Tech Tology

Join Local Hack Day:Build

2019-10-25T05:52:00.001-07:00

Local Hack Day: Build is a global hack day that enables your community to get first-hand experience bringing their ideas to life by participating in a hackathon. Over the course of 12 hours,attendees will use hardware and software to build everything from website to robots to mobile apps and more.
This is an event for all skill levels, from beginners to the most veteran developers. Workshop attendees will learn skills that they can apply in their projects,schoolwork ,job and beyond.

For further details visit: https://localhackday.mlh.io/build

RL Filters

2018-10-27T06:34:00.000-07:00

High pass filter[edit]

When the inductor is in parallel with the load while the resistor is in series with the inductor and load, this creates a high pass filter.

High pass filter has a transfer function

H(j\omega )={\frac {v_{o}}{v_{i}}}={\frac {j\omega T}{1+j\omega T}}

T={\frac {L}{R}}

Frequency response of High pass filter

\omega =0.v_{o}=0

\omega =\omega _{o}.v_{o}={\frac {v_{i}}{2}}

\omega =00.v_{o}=v_{i}

Cut off frequency,

\omega _{o}

, frequency at which

v_{o}={\frac {1}{2}}v_{i}

\omega _{o}={\frac {1}{T}}

Low pass filter[edit]

When the resistor is in parallel with the load while the inductor is in series with the resistor and load, a low pass filter is created.

Low pass filter has a transfer function

H(j\omega )={\frac {v_{o}}{v_{i}}}={\frac {1}{1+j\omega T}}

T={\frac {L}{R}}=RC

Frequency response of Low pass filter

\omega =0.v_{o}=0

\omega =\omega _{o}.v_{o}={\frac {v_{i}}{2}}

\omega =00.v_{o}=v_{i}

Cut off frequency,

\omega _{o}

, frequency at which

v_{o}={\frac {1}{2}}v_{i}

\omega _{o}={\frac {1}{T}}

A single RL circuit creates a filter with a 20.0 dB/decade, or 6.02 dB/octave, slope.

Filters and its Types-Electronics

2018-10-27T06:11:00.000-07:00

A Low Pass Filter is a circuit that can be designed to modify, reshape or reject all unwanted high frequencies of an electrical signal and accept or pass only those signals wanted by the circuits designer.
In other words they “filter-out” unwanted signals and an ideal filter will separate and pass sinusoidal input signals based upon their frequency. In low frequency applications (up to 100kHz), passive filters are generally constructed using simple RC (Resistor-Capacitor) networks, while higher frequency filters (above 100kHz) are usually made from RLC (Resistor-Inductor-Capacitor) components.

Passive filters are made up of passive components such as resistors, capacitors and inductors and have no amplifying elements (transistors, op-amps, etc) so have no signal gain, therefore their output level is always less than the input.

Filters are so named according to the frequency range of signals that they allow to pass through them, while blocking or “attenuating” the rest. The most commonly used filter designs are the:

The Low Pass Filter – the low pass filter only allows low frequency signals from 0Hz to its cut-off frequency, ƒc point to pass while blocking those any higher.
The High Pass Filter – the high pass filter only allows high frequency signals from its cut-off frequency, ƒc point and higher to infinity to pass through while blocking those any lower.
The Band Pass Filter – the band pass filter allows signals falling within a certain frequency band setup between two points to pass through while blocking both the lower and higher frequencies either side of this frequency band.

Simple First-order passive filters (1st order) can be made by connecting together a single resistor and a single capacitor in series across an input signal, ( VIN ) with the output of the filter, ( VOUT ) taken from the junction of these two components.

Depending on which way around we connect the resistor and the capacitor with regards to the output signal determines the type of filter construction resulting in either a Low Pass Filter or a High Pass Filter.

As the function of any filter is to allow signals of a given band of frequencies to pass unaltered while attenuating or weakening all others that are not wanted, we can define the amplitude response characteristics of an ideal filter by using an ideal frequency response curve of the four basic filter types as shown.

Ideal Filter Response Curves

Filters can be divided into two distinct types: active filters and passive filters. Active filters contain amplifying devices to increase signal strength while passive do not contain amplifying devices to strengthen the signal. As there are two passive components within a passive filter design the output signal has a smaller amplitude than its corresponding input signal, therefore passive RC filters attenuate the signal and have a gain of less than one, (unity).

A Low Pass Filter can be a combination of capacitance, inductance or resistance intended to produce high attenuation above a specified frequency and little or no attenuation below that frequency. The frequency at which the transition occurs is called the “cut-off” or “corner” frequency.

The simplest low pass filters consist of a resistor and capacitor but more sophisticated low pass filters have a combination of series inductors and parallel capacitors. In this tutorial we will look at the simplest type, a passive two component RC low pass filter.

The Low Pass Filter

A simple passive RC Low Pass Filter or LPF, can be easily made by connecting together in series a single Resistor with a single Capacitor as shown below. In this type of filter arrangement the input signal ( VIN ) is applied to the series combination (both the Resistor and Capacitor together) but the output signal ( VOUT ) is taken across the capacitor only.

This type of filter is known generally as a “first-order filter” or “one-pole filter”, why first-order or single-pole?, because it has only “one” reactive component, the capacitor, in the circuit.

RC Low Pass Filter Circuit

As mentioned previously in the Capacitive Reactance tutorial, the reactance of a capacitor varies inversely with frequency, while the value of the resistor remains constant as the frequency changes. At low frequencies the capacitive reactance, ( XC ) of the capacitor will be very large compared to the resistive value of the resistor, R.

This means that the voltage potential, VC across the capacitor will be much larger than the voltage drop, VR developed across the resistor. At high frequencies the reverse is true with VC being small and VR being large due to the change in the capacitive reactance value.

While the circuit above is that of an RC Low Pass Filter circuit, it can also be thought of as a frequency dependant variable potential divider circuit similar to the one we looked at in the Resistors tutorial. In that tutorial we used the following equation to calculate the output voltage for two single resistors connected in series.

We also know that the capacitive reactance of a capacitor in an AC circuit is given as:

Opposition to current flow in an AC circuit is called impedance, symbol Zand for a series circuit consisting of a single resistor in series with a single capacitor, the circuit impedance is calculated as:

Then by substituting our equation for impedance above into the resistive potential divider equation gives us:

RC Potential Divider Equation

So, by using the potential divider equation of two resistors in series and substituting for impedance we can calculate the output voltage of an RC Filter for any given frequency.

Low Pass Filter Example No1

A Low Pass Filter circuit consisting of a resistor of 4k7Ω in series with a capacitor of 47nF is connected across a 10v sinusoidal supply. Calculate the output voltage ( VOUT ) at a frequency of 100Hz and again at frequency of 10,000Hz or 10kHz.

Voltage Output at a Frequency of 100Hz.

Voltage Output at a Frequency of 10,000Hz (10kHz).

Frequency Response

We can see from the results above, that as the frequency applied to the RC network increases from 100Hz to 10kHz, the voltage dropped across the capacitor and therefore the output voltage ( VOUT ) from the circuit decreases from 9.9v to 0.718v.

By plotting the networks output voltage against different values of input frequency, the Frequency Response Curve or Bode Plot function of the low pass filter circuit can be found, as shown below.

Frequency Response of a 1st-order Low Pass Filter

The Bode Plot shows the Frequency Response of the filter to be nearly flat for low frequencies and all of the input signal is passed directly to the output, resulting in a gain of nearly 1, called unity, until it reaches its Cut-off Frequency point ( ƒc ). This is because the reactance of the capacitor is high at low frequencies and blocks any current flow through the capacitor.

After this cut-off frequency point the response of the circuit decreases to zero at a slope of -20dB/ Decade or (-6dB/Octave) “roll-off”. Note that the angle of the slope, this -20dB/ Decade roll-off will always be the same for any RC combination.

Any high frequency signals applied to the low pass filter circuit above this cut-off frequency point will become greatly attenuated, that is they rapidly decrease. This happens because at very high frequencies the reactance of the capacitor becomes so low that it gives the effect of a short circuit condition on the output terminals resulting in zero output.

Then by carefully selecting the correct resistor-capacitor combination, we can create a RC circuit that allows a range of frequencies below a certain value to pass through the circuit unaffected while any frequencies applied to the circuit above this cut-off point to be attenuated, creating what is commonly called a Low Pass Filter.

For this type of “Low Pass Filter” circuit, all the frequencies below this cut-off, ƒc point that are unaltered with little or no attenuation and are said to be in the filters Pass band zone. This pass band zone also represents the Bandwidth of the filter. Any signal frequencies above this point cut-off point are generally said to be in the filters Stop band zone and they will be greatly attenuated.

This “Cut-off”, “Corner” or “Breakpoint” frequency is defined as being the frequency point where the capacitive reactance and resistance are equal, R = Xc = 4k7Ω. When this occurs the output signal is attenuated to 70.7% of the input signal value or -3dB (20 log (Vout/Vin)) of the input. Although R = Xc, the output is not half of the input signal. This is because it is equal to the vector sum of the two and is therefore 0.707 of the input.

As the filter contains a capacitor, the Phase Angle ( Φ ) of the output signal LAGS behind that of the input and at the -3dB cut-off frequency ( ƒc ) is -45oout of phase. This is due to the time taken to charge the plates of the capacitor as the input voltage changes, resulting in the output voltage (the voltage across the capacitor) “lagging” behind that of the input signal. The higher the input frequency applied to the filter the more the capacitor lags and the circuit becomes more and more “out of phase”.

The cut-off frequency point and phase shift angle can be found by using the following equation:

Cut-off Frequency and Phase Shift

Then for our simple example of a “Low Pass Filter” circuit above, the cut-off frequency (ƒc) is given as 720Hz with an output voltage of 70.7% of the input voltage value and a phase shift angle of -45o.

Green Computing

2018-10-27T05:46:00.000-07:00

I. Introduction

Green Computing has become an innovative way on how technology and ecology converge together. With the recent years many industries and companies have turned their attention in realizing how going 'green' can benefit public relations, reduced costs, and lowering global emissions from industrial manufacturing. Though the term green computing covers a vast range of methods, from energy saving techniques, to the study of materials used in our lives, it all fundamentally breaks down to finding ways to not damage or consume all of earth's natural resources.Ultimately green computing focuses on ways in reducing overall environmental impact, its main purpose is to find and promote new ways of reducing pollution, discovering alternative technologies, and creating more recyclable products (Gingichashvili, 2007).

II. Background

The idea of green computing has been around a good time, the government themselves play a role in it. For example the Environmental Protection Agency (EPA) launched the 'energy star' program in the 90s, to promote energy efficient methods. The EPA today still plays an active role by providing not only energy effective methods, but also cost effective methods for the consumers. In 2006 the EPA established a way to save U.S. households and businesses money; "With an eye to saving U.S. households and businesses more than $1.8 billion in energy costs over the next 5 years, today EPA announced new Energy Star specifications for computers and related equipment.These new modifications are also expected to prevent greenhouse gas emissions equal to the annual emissions of 2.7 million cars."(Jones, 2006) Though the EPA is a recognizable agency, they are not the only ones who promoting new ways of going green in the technological aspect. Organizations such as European Union and TCO Certification are one of the leading groups in green computing.

III. How it is beneficial for Human Beings and Environement?

The ever rapid growth of technologies and innovations brings forth many ways on how green computing will have a positive impact, along with great benefits. The benefits of green computing is large, not only from just the consumer, or business, or country's standpoint, but a global benefit. Green computing helps reduce energy demands, waste, and money of how we use technology which positively effects the environment, and our costs.Though the method of green computing can also benefit in simple ways, methods such as turning off your computers during the night. For example, a computer left on for "24 hours will cost you between $115-160 in annual electric costs and also produce 1,500 pounds of CO2 in the atmosphere" (Schneider, 2008). By simply turning off your computer during the nights, you ultimately can save up to" 67 percent annually in your electric bill"(Schneider, 2008), along with reducing greenhouse gases. Overall the benefits of green computing will result in saving money, reducing costs, and conserving energy, along with helping the environment.

IV. Ethical Issues

Going green is not only a fashion statement, it is a real movement that begun back in 1992 with "The Energy Star Program" (Brandrick, 2009). It has become a way of life for many big corporations to try and reduce the amount of energy waste that they would normally excrete and nowadays it is not only expected to be done by such corporations but also by small businesses and individuals alike who have a moral responsibility to their community.Due to the widely known need to save energy and natural resources of our ever dyeing planet many manufacturers have come out with ideas on how to make your device energy efficient, the problem is that with good inventions come the useless ones and those are made to assume a purpose that it is not properly attributed. Some manufacturers will label a product as energy efficient just so it can be sold but sadly it will not work.

Consumers can easily be deceived to buy such products that end up causing more harm to the environment "considering the materials and energy used to manufacture it"(Brandrick, 2009) such products are truly a waste.Like the "Eco Button that promised its consumers that they would save energy and money" (Brandrick, 2009) on their PC but there was a downloadable content available on the internet that would provide the same results. It is not moral or ethical for such manufacturers to lie on the efficiency of their product but it's not illegal to say that the product was misinterpreted by the consumer.

V. Security Concerns & Social Problems

Many belief that being eco-friendly is a get rich idea from big corporations that know that if the consumer is unhappy then they will not buy their product. Even though this is somewhat true and the consumer does look bad at companies believed to be unjust, it is also true that such companies care for the environment. We all remember the "Gulf of Mexico Oil Spill" (Mufson, 2010) and how things like that can "seriously burn their reputation" (Wharton, 2007), this is why such big companies care for the environment and how they affect it. We all remember the oil spill on the gulf of Mexico in 2010 and how that dilemma hurt the BP company and still is hurting it even after a year, if they had followed all the right protocols maybe this tragedy could have been averted.

VI. Further Required Research

Advancements in green computing have become vast. There are so many new ways of combining ecology with technology, that we practically are trying a bit of everything. Such as using solar technology, solar technology now is being used on keyboards and mice now to reduce energy costs. Another green computing method is eliminating certain materials that are hazardous to the environment, and replacing them with cleaner and efficient materials which are biodegradable and eco-friendly. Even now certain computer components such as processor units have reduced heat emissions, and monitors as well with their advancement of flat screens.

Not only is green computing effecting components and other various hardware, it has changed in ways businesses use technology such as cloud computing. Cloud computing essentially is a method of a user connecting to a network or server, through the internet. Ultimately this reduces the need of businesses to have purchase more computers, which can emit greenhouse gases when left on.

The practice of green computing has essentially branched off to every form of technology out there. Cars being a great example, now with hybrids becoming mainstream, people are able to save on gas, money, and also cutting on carbon monoxide, and other various dangerous gases to the atmosphere.

Green computing has also grasped how industries market themselves, and many realize how going green in their technologies can aid them. One great example of green computing corporation is Apple. "Apple has been criticized by some environmental organizations for not being a leader in removing toxic chemicals from its new products, and for not aggressively or properly recycling its old products" (Jobs, 2009) but that has changed, when looking now upon Apple's computers, their unibody designs material is a great source to dissipate heat, along with their products being able to conserve energy very well. Not only have they implemented ways in being more eco-friendly by removing hazardous materials in their computers and products, but their manufacturing and delivering their goods has also been altered to help the environment.

VII. Conclusion

Overall the effects of green computing with its benefits, practicality, and uses are all positives. All which are great for not only the individual, but also all around the globe. By going "green" in technology we help promote an eco-friendly and cleaner environment, along with our own benefits by reducing costs, conserving energy, cutting down on waste and greenhouse gases. Green computing has definitely come a long way, but with so many new innovations coming along in regards of preserving the environment, it is safe to say that green computing is a great development.

saving  techniques  for  home  computers  to  enterprise  systems'  Client  and  Server 

machines. It is needed to find a way to handle computers and its devices for save the 

environment and society from such E-hazards.  This study provides a brief account of 

Green  Computing.  The  emphasis  of  this  study  is  on  current  trends  in  Green 

Computing;  challenges  in  the  field  of  Green Computing  and the  future trends  of 

Green Computing. Since, it is  a qualitative  research; the researcher used Individual 

interviews and Observations to collect relevant information to fulfill this research. IT 

industry is putting efforts in all  its sectors to achieve Green computing. Equipment 

recycling,  reduction  of  paper  usage,  virtualization,  cloud  computing,  power 

management, Green manufacturing are the key initiatives towards Green computing.

saving  techniques  for  home  computers  to  enterprise  systems'  Client  and  Server 

machines. It is needed to find a way to handle computers and its devices for save the 

environment and society from such E-hazards.  This study provides a brief account of 

Green  Computing.  The  emphasis  of  this  study  is  on  current  trends  in  Green 

Computing;  challenges  in  the  field  of  Green Computing  and the  future trends  of 

Green Computing. Since, it is  a qualitative  research; the researcher used Individual 

interviews and Observations to collect relevant information to fulfill this research. IT 

industry is putting efforts in all  its sectors to achieve Green computing. Equipment 

recycling,  reduction  of  paper  usage,  virtualization,  cloud  computing,  power 

management, Green manufacturing are the key initiatives towards Green computing. 

Design and Analysis of Algorithms-Course Outline

2018-09-16T02:34:00.002-07:00

Course Description: The design and analysis of algorithms is the core subject matter of Computer
Science. Given a problem, we want to (a) nd an algorithm to solve the problem, (b) prove that the
algorithm solves the problem correctly, (c) prove that we cannot solve the problem any faster, and (d)
implement the algorithm. Designing an algorithm for a computational problem involves knowledge of the
problem domain, a thorough knowledge of the data structures that are available and suitable and no small
measure of creativity. This course concentrates on the above problems, studying useful algorithm design
techniques, and methods for analyzing algorithms.

Course Objectives: The objective of the course is to develop following skills in the students of computer
science:
getting to the mathematical core of problems,
improving mathematical and algorithmic writing,
enhancing programming skills,
identifying appropriate algorithms and data structures,
analysis of algorithms for time and space complexity,
understanding of algorithm design methodologies,
identi cation of di cult questions and nding strategies to cope with them.
Main References:
Thomas H. Cormen Charles E. Leiserson Ronald L. Rivest Cli ord Stein Introduction to Algorithms
Third Edition The MIT Press Cambridge, Massachusetts
Other References:
Robert Sidgewick, Kevin Wayne, Algorithms 4th ed.
Knuth, Donald Ervin, The Art Of Computer Programming (3 volumes) Addison-Wesley, 1977.

Data Communication & Networks-Course Outline

2018-09-16T02:14:00.002-07:00

GC University Lahore

Department of Computer Science

Course Title: Data Communication & Networks

Course Code: CS - 3106

Course Duration: One Semester (16 weeks of study)

Credit Hour: 03

Course Instructor:Mr. Yahya Khurram

Course Description: To introduce students to the concept of computer communication. Analogue & digital transmission. Network Layers, Network models (OSI, TCP/IP) and Protocol Standards. Emphasis is given on the understanding of modern network concepts.

Pre-Requisite: None

Course Co-Requisite: Wireless & Mobile Communication

Course Goals & Objective

Goal No.1: Explain introduction to Data Communication, Internet Communication Model, OSI reference Model and TCP/IP protocol architecture.

Obj No.01: Explain data communication and computer networks (LAN, WAN, MAN & Wireless LAN), also explain different LAN topologies.

Obj No.02: Describe OSI reference Model in detail with each layer functionality and different protocols working at different layers.

Obj No.03: Discuss Guided transmission media (Twisted Pair, Coaxial Cable, Optical Fiber)& Unguided transmission Media.

Obj No.04: Explain TCP/IP protocol architecture in detail and comparison of TCP/IP with OSI Model.

Obj No.05: Discuss LAN protocol architecture and explain popular protocols in detail (TCP, UDP, HTTP, F|TP, SMTP etc.)

Goal No.2: Explain Digital Data Communication and Data Link control in detail

Obj No.01: Explain the Synchronous and Asynchronous communication also discusses error detection and error correction in detail.

Obj No.02: Describe flow control in data link control, Explain Stop and Wait flow control in detail.

Obj No.03: Explain different techniques of error control in detail (Stop and Wait ARQ, Go back N ARQ, Selective Reject ARQ).

Obj No.04: Discuss the High Level Data Link (HDLC) protocol functionality.

Obj No.05: Discuss Analog transmission, Digital transmission and Transmission impairments

Goal No.3: Explain & describe the Multiplexing, Spread Spectrum, Encoding Schemes and Transmission Media.

Obj No.01: Describe the concept of Frequency Division Multiplexing and Time Division Multiplexing.

Obj No.02: Explain Basic concept of Spread Spectrum, also explain Frequency Hopping spread spectrum and Direct Sequence Spread spectrum.

Obj No.03: Explain guided transmission media. Discuss wireless transmission and wireless propagation.

Obj No.04: Explain Line of sight propagation and mobile transmission in detail.

Obj No.04: Explain Switched, IP Networks and Inter-networking

Obj No.05: Explain Encoding Schemes (Digital Data – Digital Signal, Analog Data – Digital Signal, Digital Data – Analog Signal, Analog Data – Analog Signal).

Goal No.4: Describe the Circuit Switching and Packet Switching. Explain the routing in Switched Networks.

Obj No.01: Discuss Concept of Circuit switching.

Obj No.02: Discuss Circuit switching networks and control signaling in circuit switching.

Obj No.03: Explain Packet switching principles and two types of packet switching (Datagram & Virtual Circuits) . Discuss packet size in packet switching.

Obj No.04: Discuss the comparison of circuit switching and packet switching and which is better in different scenarios.

Obj No.05: Discuss the routing and circuit switching networks and packet switching networks in detail.

Teaching & Learning Strategies

The course will be taught by a combination of lectures, presentations and directed reading material. Unannounced quizzes will be taken during the lectures. All lectures may comprise of a power point presentation, handouts and white board demonstrations. The students will be given the assignments related to the topic covered during the different lecture. Each student will be asked to select a research topic and give at least one assessed presentation to the class.

Lecture Duration will be of 90 Minutes.

Time Management Matrix

Goal No.1 18%: 3 Weeks
Goal No.2 25%: 4 Weeks
Goal No.3 25%: 4 Weeks
Goal No. 4 32%: 5 Weeks

Assessment Strategy

Semester Work (Assignments +Quizzes) : 05% + 15 %
Mid Term : 20%
Final Term (Objective + Subjective): 10 + 50 = 60%

Evaluation is based on how well the student will perform in class, assignments and quizzes. Performance will be monitored throughout the semester. The examination will test the student’s understanding of the various concepts discussed during the course.

The written examination requires students to complete a theoretical paper covering all aspects of the course.

Recommended Text Books

1. Data & Computer Communications by William Stallings, 8^th edition

2. Computer Networks, 5^th Edition, A.S Tanenbaum, D.J Wetherall

3. Data Communications and Networking, Behrouz A. Forouzan, 4^th Edition

Microsoft Urges Congress to Regulate Use of Facial Recognition

2018-07-13T09:36:00.001-07:00

Bradford L. Smith, the company’s president, compared the technology to products like medicines and cars that are highly regulated, and he urged Congress to study it and oversee its use.“We live in a nation of laws, and the government needs to play an important role in regulating facial recognition technology,”

Mr. Smith wrote. He added: “A world with vigorous regulation of products that are useful but potentially troubling is better than a world devoid of legal standards.”

Now, Microsoft is moving to position itself as an industry leader by calling for government regulation of facial recognition, and for “the development of norms around acceptable uses,” of the technology. The company may also be trying to get out ahead of a budding movement in states like California to tightly regulate the technology.

Mr. Smith said Congress should appoint a commission to study the issue and make recommendations on potential regulations. The Federal Trade Commission has already examined facial recognition, recommending in a report that certain companies “provide consumers with an easy-to-use choice not to have their biometric data collected and used for facial recognition.”

Mr Smith

Microsoft markets facial recognition software that can detect faces in photos, as well as facial features like hair color, and emotions like anger or disgust, according to the company's site.

The company also markets facial recognition software that “enables you to search, identify, and match faces in your private repository of up to one million people,” the site said. Uber has used the technology to verify drivers’ identities, according to Microsoft marketing materials.

Mr. Smith wrote in the blog post that Microsoft was examining its own development and marketing of the technology.

A recent study led by an M.I.T. researcher found that facial recognition software from Microsoft and IBM was much more accurate in identifying white men than darker-skinned females. Mr. Smith said the company was working to improve the accuracy of its facial recognition and to reduce the potential for bias.

GCU BSCS Entry Test 2018 Details

2018-07-11T08:34:00.002-07:00

For more Details and Preparation Sources.Contact through

Email: saadaslam816@gmail.com

Facebook: saadaslam7355

WhatsApp: 0302-4609017

Or post your comments below in the comments section

DSA Mid Term Syllabus

2018-04-06T11:58:00.000-07:00

DSA Pre-Mid Topics

1. All General Algorithms related to search and sort.

2. Arrays. General arrays and traversal algorithms.

a. Polynomial algorithms, general matrices.

b. Dynamic arrays, dynamic declaration, dynamic growth and shrinking.

c. Inorder insertion. Deletion, inorder deletion.

d. 2D array search, traversal. Complex 2D/3D loops for any purpose.

3. Algorithm techniques:
Brute Force vs Divide & Conquer.

4. Time cost. Loop cost, nested loop, initialization and boundary checking cost. Exact cost verses order of complexity.

5. Stack:
using Array and Linked list. Stack ordering, ToH problem, in-order insertion in stack using a temporary stack, stack search and delete using temporary stack, Sorting using stack.

6. Expression evaluation: Complete.

7. Recursion:
Recursion for Brute-force and Divided & Conquer.

8. Queue:
using array and linked list. General Queue, Priority Queue. Techniques to recover space before head of queue. Circular Queue. Searching/Sorting using queue.

9. Linked list:
Single, double, circular link list. List as stack or queue. Insertlast, insertfirst, insertInorder, deletelast, deletefirst, deleteAt, deleteAfter, deletebefore, searchAndDeleteetc in all types of link lists. Insert an existing Node(without creation). Attach/Detach techniques. Ordering/Sorting of existing link list.

DSA-Mids Solution-2018

2018-04-06T04:35:00.000-07:00

Roll No:-BSCS-2017 Name:____________ Section:

GC UniversityLahore

Solution of DSA MidTerm Exam Spring-18Selester-4

Time Allowed: 10Minutes MCQ Part Set “X” Max. Marks: 10

Q#1: Answer MCQ questions by FILLING THE CIRCLE.

1. Brute Force Sorting techniques require comparison of each element with each other element, and therefore run in _____________ time?

A	Linear	¡
B	Fixed	¡
C	N	¡
D	N²	¡

2. Brute-force Sorting algorithm’s Average case time is ____________ ?

A	N	¡
B	N/2	¡
C	Constant	¡
D	Quadratic.	¡

3. Only method to dynamically increase/decrease capacity of __________ data structure is to dynamically delete and then allocate ccording to new size.

A	Singly Linked list	¡
B	Circular Linked list	¡
C	Array	¡
D	All of above	¡

4. Operators stack used in expression evaluator maintains __________ priorityof operators from top to bottom.

A	FIFO	¡
B	LIFO	¡
C	Descending	¡
D	Ascending	¡

5. The _______________has the advantage that compaction is not required.

A	Circular buffer	¡
B	Circular Linked list	¡
C	Only A is correct.	¡
D	Both A and B are correct.	¡

6. General order of operations when inserting a new node in any dynamic data structure is to adjust the pointers of_______________?

A	New node, then adjacent nodes, then globals.	¡
B	Globals, then new node, then adjacent.	¡
C	Adjacent nodes, then globals, then new node.	¡
D	New node, then globals, then adjacent.	¡

7. Following is the correct PRE-FIX form of A+B*C/D?

A	+A*B/CD	¡
B	ABCD/*+	¡
C	A+*B/CD.	¡
D	None of above.	¡

8. Priority Queue is different from simple queue as it requires _________________.

A	Compaction	¡
B	In-order deletion	¡
C	In Order insertion.	¡
D	Deletion from both ends.	¡

9. A[i -1 ] = i* A[i] is the typical technique to find ___________ of polynomial?

A	Root	¡
B	Antiderivative	¡
C	Derivative	¡
D	One of above (actual statement was None of above)	¡

10. Divide & Conquer Algorithms have the advantage that Time Cost is reduced to _____________________.

A	Log(N)	¡
B	Quadratic.	¡
C	Linear	¡
D	N².	¡

Roll No:-BSCS-2016Name:______________Section:_____

Q1	Q2	Q3	Q4	Total

GC University Lahore

Solution of DSAMidTerm Exam Spring-18Semester-4

Time Allowed: 1 Hour 5 Minutes Subjective Part Max. Marks: 10

All necessary boundary checks and special cases must be applied.

Note: Following solution is not complete. DIY means Do it yourself. Boundary checks and special cases are applied in some answers.

Q#2: a) Number x is to be inserted into a linear doubly linked list in order. Write pseudocode.

Node * t=new node(x);

If(!first){first=last=t; return;}//empty case

If(first-> data > =x){//new node to be inserted even before first.

t-> next=first;

first->prev= t;

first =t;

}

If(last->data<x){insert at last; }//DIY

Node * t1=first;

While(t1 ->next->data<x || t1->next!=NULL){t1=t1->next;}//search for node’s position or last, then insert after t1

//step-1 set new node’s pointers

t->prev=t1;

t->next=t1->next;

step-2: set adjacent nodes pointers

t1->next->prev=t;

t1->next=t;

//step-3 set global pointers. Not needed because node is inserted in between first and last

b) Write pseudocode to store Antiderivative of Polynomial Array A into array B. Consider contant of integration is zero.

B[0]=0;//coefficient of constant term. i.e constant of integration

For(inti=1;i<N; i++){

B[i]= A[i-1]/i; i-1th power is now ith power but divided by i power.

}

c)Write pseudocode to find an element x and delete its previous node in singly linked list.

Bool findAndDeletePrev(int x){

If(first->data= =x )return false;//there is no node previous to first

If((first->next->data= =x) {//data matches next to first, therefore delete first

Node * t=first;

First=first->next;

Delete t;

}

Node * t=first;

While(t->next->next->data!=x|| t->next->next!=NULL)t=t->next;//scan for next to next node matching data;

If(t==NULL) return false;//element not found

If(t==last)// assign last pointer to second last, then delete last. DIY.

}

Q3: a) Write pseudocode to search &remove a value x from a sortedlinearsingly linked list.

If(!first) return false;//empty list

If(first->data> x|| last->data<x) {// x does not lie in range of sorted list.

Return false;

}

If(first->data==key){//first node to be deleted. DIY

}

Node * t=first;

While(t->next->data<=x|| t->next!=NULL){//find node whose next matches

T=t->next;

}

If(t->next-data==x)//above loop broken before required node

{

//delete t-> next. DIY

}

Q.3: b) What is problem with following code for insertion into a circular queue. Give reasons and write correct version.

bool insert(int x){

If (head = = tail) {//circular queue is full

Return False;

}

else{

If(tail= = MAX)compact( );

A[tail + +] = x;

Return True;

}

1. CQueueis full only when head = = tail+1, (not when head = = tail)

2. Tail = = MAX does not apply to circular queue and compaction is not required.

3. if(tail = = MAX) tail = 0;

thenA[tail]= x; Tail + +;

c) Write pseudocdeto implementinsertlast( int x) for a circular double linked list.

Node * t=new node(x);

If(!first)[first=t;first->prev=first->next=t; return;} insert to empty

If(first->next==first){t->prev=t->next=first;first->next=first->prev=t; return;}

t->next=first;

t->prev=first->prev;

first->prev=t; return;

Q. 3 d)Convert the following expression into Postfix form using stack technique. Then evaluate the answer using stack. Show dry run steps, especially stack states.

Conversion Steps

Infix=1+9/3^2^1 *4 – 7^2/7*7*7/7

Postfix=1932^1^/*4*+72^7/7*77/*-



^	^			/
/	/	*		*
+	+	+	-	-

Evaluation Steps

1932^1^/*4*+72^7/7*77/*-

	^	=		^	=
2	2		1	1
3	3	9	9	9	9
9	9	9	9	9	9
1	1	1	1	1	1

Q. 4: a) Write typical pseudocode to insert a number x into a dynamic array, with the feature that array grows double when space utilization is greater than 70%.

If(SIZE > = MAX * 0.7)//if utilization is around 70%

{

Int * t= new int(MAX);// allocate a new array

For(int I = 0 ;I < SIZE ; i++ ) t[i] = A[i]; copy elements

Delete A;

A=new int(MAX * 2);//delete and re-allocate double size

For(int I = 0 ; I < SIZE; i++) A[i] = t[i];//copy back

}

A[SIZE++]=x; //insert-last, if no other method is specified

b) Write pseudocode to search and modify an element x in a sorted array, such that its new value becomes x1 and it travels to its new position in-order.

Int index = search(A, 0,N,x)//can use binary search to find position of x

If(index= = -1) return false; //element not found, search returs -1

int index2 = search(A,0,N,x1);//find its new position.

If(index2>index){//element has to be shifted righttside

For(inti=index2;i<=index ;i--)A[i-1]=A[i];//copy each element to its left side

}

Else{//element is to be shifted leftside

For(inti=index;i<=index2;i++)A[i-1]=A[i];

}

A[index2]=x2;

//make necessary corrections. Above code is just a concept

Following is recursive definition of a mathematical formula. Write the recursive function. Apply proof of correctness to check if algorithm is correct or not.

Is it divide &conqer or not?

Is it branch recursion?

x¹= x

x^N = { x * (x^(N-1)/2)² for N odd

= { (x^N/2)²for N even

IntrecPow(float x, int N)

{

If(N==1)return x;//base case

If(N%2){//odd-case

N=N-1;

Float y= recPow(x,N/2);

Return x*y*y;

}

Else{//even-case

Float y= recPow(x,N/2);

Return y*y;

}

This is Divide & Conquer. This is branch recursion, but only one branch executes in each call.

Proof of correctness:

Base case: x^N for N=1 is x¹ = x itself. hencebasecase proved

Recursive call:

Even case:algebraically x^AB = (x^A)^B so x^N = (x^N /2)²because N/2 * 2= N

(x^N /2)²= (x^N /2) * (x^N /2)by square rule. So even case is proved.

Odd case: N is decremented to smaller even number. Then recursive call is generated for even case N – 1.

Then x is multiplied with result. As x^N = x * x^N-1. henceproved.

d) Fill the following table, assign precedence numbers to all operators and also mention associativity is right-to- left ot left-to-right.

Operator	Precedence	Associativity
=	0	Left-right
- (subtract)	4	Left-right
*	3	Left-right
^	1	Right-left
/	2	Left-right
+	4	Left-right

Coupling and Cohesion-OOP

2018-03-31T23:31:00.000-07:00

Name: Saad Aslam

Roll No: 0043-BSCS-16

Section: E2

Subject: Object Oriented Programming

Topics :

Ø Coupling

Ø Reduce Coupling

§ Calling Separate Methods

§ Encapsulation

§ Responsibilty driven design

§ Localizing Changes

Ø Implicit Coupling

Ø Cohesion

Ø Refactoring

§ Refactoring and testing

§ Refactoring for language independence

CH #6 Coupling and Cohesion

REDUCE COUPLING

Ø By calling separate methods:

If same code is used in different methods again and again than instead of writing the same code in different methods ,we can implement a separate method and write that code which is similar in different methods and then call that code in that methods where the code was used.

Ø Encapsulation:

To avoid tight coupling ,we need to use encapsulation by making all public fields to public .This will help us in decoupling the classes and hence decrease in tight coupling.

(“Never make fields public!”)

Proper

encapsulation in

classes reduces

coupling and thus

leads to a better

The encapsulation guideline (hiding implementation information from view) suggests that only information about what a class can do should be visible to the outside, not about how it does it.This has a great advantage: if no other class knows how our information is stored, then we can easily change how it is stored without breaking other classes.

Ø Responsibility-driven design:

Responsibility-driven design expresses the idea that each class should be responsible for handling

its own data. Often, when we need to add some new functionality to an application, we

need to ask ourselves in which class we should add a method to implement this new function.

Which class should be responsible for the task? The answer is that the class that is responsible

for storing some data should also be responsible for manipulating it.

Ø Localizing Changes:

Another aspect of the decoupling and responsibility principles is that of localizing change. We

aim to create a class design that makes later changes easy by localizing the effects of a change.

Ideally, only a single class needs to be changed to make a modification. Sometimes several

classes need change, but we then aim at this being as few classes as possible. In addition, the

changes needed in other classes should be obvious, easy to detect, and easy to carry out.

To a large extent, we can achieve this by following good design rules such as using

responsibility-driven design and aiming for loose coupling and high cohesion. In addition, however,

we should have modification and extension in mind when we create our applications. It is important

to anticipate that an aspect of our program might change, in order to make this change easy.

WORSE FORM OF COUPLING

Implicit Coupling:

There is an even worse form of coupling: implicit coupling.

Implicit coupling is a situation where one class depends on the internal information of another,but this dependence is not immediately obvious. The tight coupling in the case of the public fields was not good, but at least it was obvious. If we change the public fields in one class and forget about the other, the application will not compile any more and the compiler will point out the problem. In cases of implicit coupling, omitting a necessary change can go undetected.

This is a fundamental problem, because every time a command is added, the help text needs to be changed, and it is very easy to forget to make this change. The program compiles and runs, and everything seems fine. A maintenance programmer may well believe that the job is finished and release a program that now contains a bug.

This is an example of implicit coupling.

THINKING AHEAD

Q:What is Model View Controller Pattern?

COHESION

A unit of code should always be responsible for one, and only one, task. The principle of cohesion can be applied to classes and methods: classes should display a high degree of cohesion, and so should methods.

Ø Cohesion in Methods:

When we talk about cohesion of methods, we seek to express the ideal that any one method should be responsible for one, and only one, well-defined task.We can see an example of a cohesive method in the Game class. This class has a private method named printWelcome to show the opening text, and this method is called when the game starts in the play method.

Ø Cohesion in Classes:

The rule of cohesion of classes states that each class should represent one single, well-defined entity in the problem domain.

BENEFITS OF COHESION

There are several ways in which high cohesion benefits a design. The two most important ones

are readability and reuse

REFACTORING

Refactoring is the activity of restructuring existing classes and methods to adapt them to

changed functionality and requirements. Often in the lifetime of an application, functionality is

gradually added. One common effect is that, as a side-effect of this, methods and classes slowly

grow in length.

Refactoring is the rethinking and redesigning of class and method structures. Most commonly,the effect is that classes are split in two or that methods are divided into two or more methods.

Refactoring can also include the joining of multiple classes or methods into one, but that is less

common than splitting.

Ø Refactoring and testing:

Before we provide an example of refactoring, we need to reflect on the fact that, when we

refactor a program, we are usually proposing to make some potentially large changes to something

that already works. When something is changed, there is a likelihood that errors will be

introduced. Therefore, it is important to proceed cautiously; and, prior to refactoring, we should establish that a set of tests exists for the current version of the program. If tests do not exist, then we should first decide how we can reasonably test the functionality of the program and record those tests (for instance, by writing them down) so that we can repeat the same tests later.

Refactoring will follow the following two steps:

■ The first step is to refactor in order to improve the internal structure of the code, but without

making any changes to the functionality of the application. In other words, the program should,

when executed, behave exactly as it did before. Once this stage is completed, the previously

established tests should be repeated to ensure that we have not introduced unintended errors.

■ The second step is taken only once we have reestablished the baseline functionality in the refactored version. Then we are in a safe position to enhance the program. Once that has been

done, of course, testing will need to be conducted on the new version.

Doing good refactoring is as much about thinking in a certain mindset as it is about technical skills. While we make changes and extensions to applications, we should regularly question whether an original class design still represents the best solution. As the functionality changes, arguments for or against certain designs change. What was a good design for a simple application might not be good any more when some extensions are added.

Recognizing these changes and actually making the refactoring modifications to the source

code usually saves a lot of time and effort in the end. The earlier we clean up our design, the

more work we usually save.

Ø Refactoring for language independence:

If we want to have language independence in the program, then ideally we should have just one place in the source code where the actual text of command words is stored and have everywhere else refer to commands in a language-independent way. A programming language feature that makes this possible is enumerated types, or enums.

In its simplest form, an enumerated type definition consists of an outer wrapper that uses the word enum rather than class and a body that is simply a list of variable names denoting the

set of values that belong to this type. By convention, these variable names are fully capitalized.

We never create objects of an enumerated type. In effect, each name within the type definition

represents a unique instance of the type that has already been created for us to use. We refer to these instances as CommandWord.GO, CommandWord.QUIT, etc. Although the syntax for using them is similar, it is important to avoid thinking of these values as being like the numeric class constants Despite the simplicity of their definition, enumerated type values are proper objects and are not the same as integers.

SUMMARY

Ø Good class design can make a huge difference when an application needs to be corrected, modified,or extended. It also allows us to reuse parts of the application in other contexts (for example, for other projects) and thus creates benefits later.

Ø There are two key concepts under which class design can be evaluated: coupling and cohesion.

Ø Coupling refers to the interconnectedness of classes, cohesion to modularization into appropriate units. Good design exhibits loose coupling and high cohesion.

Ø One way to achieve a good structure is to follow a process of responsibility-driven design. Whenever we add a function to the application, we try to identify which class should be responsible for which part of the task.

Ø When extending a program, we use regular refactoring to adapt the design to changing requirement and to ensure that classes and methods remain cohesive and loosely coupled.

CONCEPT SUMMARY

■ Coupling The term coupling describes the interconnectedness of classes. We strive for loose

coupling in a system—that is, a system where each class is largely independent and communicates with other classes via a small, well-defined interface.

■ Cohesion The term cohesion describes how well a unit of code maps to a logical task or entity.In a highly cohesive system, each unit of code (method, class, or module) is responsible

for a well-defined task or entity. Good class design exhibits a high degree of cohesion.

■ Code duplication Code duplication (having the same segment of code in an application more

than once) is a sign of bad design. It should be avoided.

■ Encapsulation Proper encapsulation in classes reduces coupling and thus leads to a better

design.

■ Responsibility-driven design Responsibility-driven design is the process of designing

classes by assigning well-defined responsibilities to each class. This process can be used to

determine which class should implement which part of an application function.

■ Localizing change One of the main goals of a good class design is that of localizing change:

making changes to one class should have minimal effects on other classes.

■ Method cohesion A cohesive method is responsible for one, and only one, well-defined task.

■ Class cohesion A cohesive class represents one well-defined entity.

■ Refactoring Refactoring is the activity of restructuring an existing design to maintain a good

class design when the application is modified or extended.

■ Switch statement A switch statement selects a sequence of statements for execution from

multiple different options.

Syllabus Before Mids-OOP

2018-03-31T23:22:00.003-07:00

OOP(Object Oriented Programming)

Topics:

1. Compilation process in java

2. Bytecode

3. Objects

4. Classes

5. Instance variables, State

6. Methods, Behaviours

7. Classes as Reference type

8. Classes to create object

9. Passing object as parameter to different objects. =>Student s2=new Student(s); (*Imp)

10. Primitive and non primitive data types

11. Inheritance(*Imp)

12. Using Is-A relationship(*Imp)

13. Polymorphism(*Imp)

14. Overloading and overriding(*Imp)

15. Encapsulation(*Imp)

i. Basics of encapsulation

16. Setter and getters methods(*Imp)

17. Using keyword “This”(*Imp)

18. Static and non static variables(*Imp)

19. Calling a non static method into static causes error why?(*Imp)

20. Constructor(*Imp)

21. Byte code

22. Student s=new Student(); Printing “s” which is a reference and incrementing. (*Imp)

23. Scanner class

24. Abstraction

25. Modularization

26. JVM(Java Virtual Machine)

27. Collection

28. Array List(*Imp)

29. Iterators (advantage of removing objects)

30. For each loop(not used for removing objects)

31. Difference btw for loop ,foreach loop and iterators(*Imp)

32. Hash Map (key,value)(*Imp)

33. Order of Elements in HashMap

34. HashCode for key and Equals for value

35. HashSet(For uniqueness)(*Imp)

36. Order of Elements in HashSet

37. How to split a String(*Imp)?

38. Equality and identity of string

39. Equals for String(*Imp)

40. Trim method(For reducing extra spaces)

41. Design of Class (Bad and Better –Ch 6 in new book)

42. Association

43. Aggregation

44. Coupling (Bond between classes)

45. Cohesion

46. Steps for Reduce Coupling

· Methods Calling

· Encapsulation

· Responsibilty –Driven

Important Points-OOP

2018-03-31T23:11:00.000-07:00

· Collection, Set, List an interface in the Collection Framework.

· HashSet restricts Duplicate elements

· ArrayList has the ability to grow dynamically

· The accuracy and efficiency of a HashMap can be guaranteed with override equals and override hashCode methods

· A Hash Map allows only one null key value and many null values

· ListIterator allows the collection to iterate in both direction

· Map doesn’t implement the collection interface

· The default capacity of arraylist is 10

· Linked List provides the better performance of insertion and removal from the middle of list

· An unsorted array has search time capacity of “n”.

· After resizing the size of arrayList is increased by 50%.

· Generics guarantees type Safety in collection

· HashSet internally uses HashMap

· The most used interfaces in the collection framework are list,map,set.

· The root interface of Java Collection framework hierarchy is Collection

· HashMap,HashSet and ArrayList are not synchronized

· ArrayList implements List,Randomacess,Cloneable

· HashSet allows storage of only one null value

SISO,SIPO Shift Registers-DLD

2018-03-31T23:00:00.001-07:00

Prepared by :Saad Aslam

Shift Register

Ø The Shift Register is another type of sequential logic circuit that can be used for the storage or transfer of data in the form of binary numbers.

Ø This Sequential device loads the data present on its inputs and then moves or “Shifts” It to its output once every clock cycle,hence the name Shift Register.

Ø Being a sequential logic ,it is not only affected by the present inputs ,but also, the past inputs.

Types of Shift Registers:

1. Serial-In/Serial-Out(SISO)

2. Serial-In/Parallel-Out(SIPO)

3. Parallel-In/Serial-Out(PISO)

4. Parallel-In/Parallel-Out(PIPO)

1. Serial-In/Serial-Out(SISO)

Serial-In to Serial-Out(SISO) –the data is shifted serially “IN” and serially “OUT” of the register, one bit at a time in either a left or right direction under clock control

Let us assume that all the flip flops have just been RESET and all the outputs are at logic level “0” ie no Serial output.If a logic “1” is connected to DATA input of first flip flop (FF-1) then on the first clock pulse the output of first flip flop(FF-1) will be set High to logic “1” with all the outputs stil remaining LOW at logic “0”.Assume now that Data input of FF-1 has returned LOW again to logic “0” giving us one data pulse or 0-1-0.

The second clock pulse will change the logic of FF-1 to logic “0” and the output of second flip flop(FF-2) will set to High logic “1” as its input D has the logic “1”.The logic “1” has now moved or been shifted from FF-1 to FF-2.

When the third clock pulse arrives this logic “1” will shift from FF-2 to third flip flop (FF-3) and the output of FF-3 will have logic “1” .This process will continue until the arrival of fifth clock pulse which sets all the outputs back to logic level “0”.

The effect of each clock pulse is to shift the data contents of each stage one place to the right ,until the complete data value is stored in the register.This data value can now be read serially by the output of the last flip flop FF-4.

2. Serial-IN/Parallel-Out(SIPO)

Serial-In to Parallel-Out(SIPO)-the data is shifted serially “IN” and parallely “OUT” of the register, one bit at a time in either a left or right direction under clock control.

Block Diagram:

Working:

It has same pattern as SISO but instead of having the output serially by the last flip flop ,the outputs are taken by each flip flop at the end.Let us assume that all the flip flops have just been RESET and all the outputs are at logic level “0” ie no parallel output.If a logic “1” is connected to DATA input of first flip flop (FF-1) then on the first clock pulse the output of first flip flop(FF-1) will be set High to logic “1” with all the outputs stil remaining LOW at logic “0”.Assume now that Data input of FF-1 has returned LOW again to logic “0” giving us one data pulse or 0-1-0.

DSA Assignment Guidelines

2018-03-31T11:57:00.000-07:00

Guidelines for submitting Assignments

1. Each assignment will be of 10 marks.

2. One mark will be deducted if assignment is submitted on last date.

3. After last date, 2 marks per day will be deducted.

4. 7 marks will be given for exactly following general requirements and hints. Extra 3 marks will be for those who implement all requirements and do more than required.

5. Marks will not be deducted for small logical errors.

6. Please do not get assignment from others or give to others. Also, do not get or give assignment help. Get help on data structures and programming. If you want to help others, teach them programming and algorithms. Assignment is for self preparation.

7. 5 Negative marks will be given for copied assignment for the first time. F grade will be given for 2^nd time submission of copied assignment.

8. Please email source code to saeedturk@yahoo.com, (before submitting) or bring in USB. Also bring Printed Source Code at submission.

Assignment submission and viva will start from 3^rd April 2018

DSA Pre-Mid Assignment 2018

1. Predator-Prey Simulation on a 2D Array.

Predator is always attracted towards Prey while prey is always repelled away from predator. If predator position is denoted by P_i,j, and prey position is denoted by p_ij,attraction/repulsion is directly proportional to distance between P and p. Distance between two elements of 2D array can be calculated using Cartesian formula. Movements of predator and prey are always in row or column wise. Movement of predator is always towards prey, while movement of prey can be away from predator but with some random long /medium jumps in any direction. Can predator ever catch the prey? Can you optimize your algorithm to guarantee that predator will never be able to catch prey?

2. Stack based Expression evaluator

As discussed in class, an expression evaluator consists of two main components.

1. Infix to Postfix converter

2. Postfix expression evaluator.

Both parts use stacks(of different types, obviously).

Your expression evaluator should contain following core functionality.

General requirements

1. Input an infix expression.

2. Operands should be single digit.

3. operators +, -, * , /, ^,

4. parenthesis should also be supported. ( it is simple. Starting parenthesis: push in operand stack. Ending parenthesis: pop all operators until a starting parenthesis is found. Ending and starting parenthesis are not added to output postfix expression. Also, if a low priority operator comes, it will pop all higher/equal priority operators until a starting parenthesis)

5. print output postfix expression on screen.

6. Use same expression or a newly input expression from user.

7. Calculate solution of postfix expression.

8. If any error is found in calculation, indicate as syntax error.

Advanced: Above mentioned requirements will get you 7/10 marks. For 3 more marks.

1. Input operands may be multidigit and decimal numbers.

2. Input operands may be variable.

3. Operands may be more complex. Like exp(x), sin(x), a+b(c+d), -a%b, etc.

Assignment 3: Pure dynamic array: Develop a pure dynamic array class, as discussed in class.
Dynamic array has following features.

1. Array size can be dynamically set. Array can grow and shrink dynamically and automatically. Growth will double the array size and should be when array is approximately 95% utilized. Shrinkage will decrease the size to half and should be called when array is about 40% utilized.

2. Implement instertAt, InsertinOrder, insertlast, deleteAt, deleteLast, searchAndDelete etc methods.

3. Implement array traversal, i.e. just screen output.

4. Array input, output, search, delete, insertInOrder etc as a menu based program.

Basic Structure of Assembly Language

2018-03-30T11:09:00.001-07:00

Prepared by: Saad Aslam

Assembly language programs divide roughly into five sections

header
equates
data
body
closing

The Header

The header contains various directives which do not produce machine code
Sample header:

%TITLE "Sample Header"
.8086
.model small
.stack 256

Named Constants

Symbolic names associated with storage locations represent addresses
Named constants are symbols created to represent specific values determined by an expression
Named constants can be numeric or string
Some named constants can be redefined
No storage is allocated for these values

Equates

Constant values are known as equates
Sample equate section:

Count EQU 10
Element EQU 5
Size = Count * Element
MyString EQU "Maze of twisty passages"
Size = 0

= is used for numeric values only
Cannot change value of EQU symbol
EQUated symbols are not variables
EQU expressions are evaluated where used; = expressions are evaluated where defined

The Data Segment

Begins with the .data directive
Two kinds of variables, initialized and uninitialized.
Initialized variables take up space in the program's code file
Declare uninitialized variables after initialized ones so they do not take up space in the program's code file

Reserving space for variables

Sample DATA SEGMENT

.data
numRows DB 25
numColumns DB ?
videoBase DW 0800h

DB and DW are common directives (define byte) and (define word)
The symbols associated with variables are called labels
Strings may be declared using the DB directive:

aTOm DB "ABCDEFGHIJKLM"

Program Data and Storage

Pseudo-ops to define data or reserve storage

DB - byte(s)
DW - word(s)
DD - doubleword(s)
DQ - quadword(s)
DT - tenbyte(s)

These directives require one or more operands

define memory contents
specify amount of storage to reserve for run-time data

Defining Data

Numeric data values

100 - decimal
100b - binary
100h - hexadecimal
'100' - ASCII
"100" - ASCII

Use the appropriate DEFINE directive (byte, word, etc.)
A list of values may be used - the following creates 4 consecutive words

DW 40Ch,10b,-13,0

A ? represents an uninitialized storage location

DB 255,?,-128,'X'

Naming Storage Locations

Names can be associated with storage locations

ANum DB -4
DW 17
ONE
UNO DW 1
X DD ?

These names are called variables
ANum refers to a byte storage location, initialized to FCh
The next word has no associated name
ONE and UNO refer to the same word
X is an uninitialized doubleword

Arrays

Any consecutive storage locations of the same size can be called an array

X DW 040Ch,10b,-13,0
Y DB 'This is an array'
Z DD -109236, FFFFFFFFh, -1, 100b

Components of X are at X, X+2, X+4, X+6
Components of Y are at Y, Y+1, �, Y+15
Components of Z are at Z, Z+4, Z+8, Z+12

DUP

Allows a sequence of storage locations to be defined or reserved
Only used as an operand of a define directive

DB 40 DUP(?)
DW 10h DUP(0)
DB 3 DUP("ABC")
DB 4 DUP(3 DUP (0,1), 2 DUP('$'))

Word Storage

Word, doubleword, and quadword data are stored in reverse byte order (in memory)

Directive      Bytes in Storage
DW 256         00 01
DD 1234567h    67 45 23 01
DQ 10          0A 00 00 00 00 00 00 00
X DW 35DAh     DA 35

Low byte of X is at X, high byte of X is at X+1

The Program Body

Also known as the code segment
Divided into four columns: labels, mnemonics, operands, and comments
Labels refer to the positions of variables and instructions, represented by the mnemonics
Operands are required by most assembly language instructions
Comments aid in remembering the purpose of various instructions

An example

Label    Mnemonic   Operand     Comment
---------------------------------------------------------
         .data
exCode   DB         0          ;A byte variable
myWord   DW         ?          ;Uninitialized word var.
         .code
MAIN    PROC
         mov        ax,@data   ;Initialize DS to address
         mov        ds,ax      ; of data segment
         jmp        Exit       ;Jump to Exit label
         mov        cx,10      ;This line skipped!
Exit:    mov        ah,04Ch    ;DOS function: Exit prog
         mov        al, exCode ;Return exit code value
         int        21h        ;Call DOS. Terminate prog
MAIN     ENDP                  ;End Program
         END        MAIN       ; and specify entry point

The Label Field

Labels mark places in a program which other instructions and directives reference
Labels in the code segment always end with a colon
Labels in the data segment never end with a colon
Labels can be from 1 to 31 characters long and may consist of letters, digits, and the special characters ? . @ _ $ %
If a period is used, it must be the first character
Labels must not begin with a digit
The assembler is case insensitive

Legal and Illegal Labels

Examples of legal names

COUNTER1
@character
SUM_OF_DIGITS
$1000
DONE?
.TEST

Examples of illegal names

TWO WORDS contains a blank
2abc begins with a digit
A45.28 . not first character
YOU&ME contains an illegal character

The Mnemonic Field

For an instruction, the operation field contains a symbolic operation code (opcode)
The assembler translates a symbolic opcode into a machine language opcode
Examples are: ADD, MOV, SUB
In an assembler directive, the operation field contains a directive (pseudo-op)
Pseudo-ops are not translated into machine code; they tell the assembler to do something

The Operand Field

For an instruction, the operand field specifies the data that are to be acted on by the instruction. May have zero, one, or two operands

NOP             ;no operands -- does nothing
INC AX          ;one operand -- adds 1 to the contents of AX
ADD WORD1,2     ;two operands -- adds 2 to the contents
                ; of memory word WORD1

In a two-operand instruction, the first operand is the destination operand. The second operand is the source operand.
For an assembler directive, the operand field usually contains more information about the directive.

The Comment Field

A semicolon marks the beginning of a comment field
The assembler ignores anything typed after the semicolon on that line
It is almost impossible to understand an assembly language program without good comments
Good programming practice dictates a comment on almost every line

Good and Bad Comments

Don't say something obvious, like

MOV CX,0 ;move 0 to CX

Instead, put the instruction into the context of the program

MOV CX,0 ;CX counts terms, initially 0

An entire line can be a comment, or be used to create visual space in a program

;
; Initialize registers
;
MOV AX,0
MOV BX,0

The Closing

The last lines of an assembly language program are the closing
Indicates to assembler that it has reached the end of the program and where the entry point is

MAIN ENDP ;End of program
END MAIN ; entry point for linker use

END is a pseudo-op; the single "operand" is the label specifying the beginning of execution, usually the first instruction after the .code pseudo-op

Assembling a Program

The source file of an assembly language program is usually named with an extension of .asm

edit myprog.asm

The source file is processed (assembled) by the assembler (TASM) to produce an object file (.obj)

tasm myprog produces myprog.obj

The object file must be linked by the linker (TLINK) to produce an executable file (.exe)

tlink myprog produces myprog.exe

Dealing with Errors

TASM will report the line number and give an error message for each error it finds
Sometimes it is helpful to have a listing file (.lst), created by using TASM with the -l option
The .lst file contains a complete listing of the program, along with line numbers, object code bytes, and the symbol table

Using the Debugger

Useful for logic errors that the assembler misses
See the text for a complete tutorial
You do not need to use the TDH386.SYS driver or the TD386.EXE debugger with the latest version of the assembler
To use the debugger on myprog.asm

tasm /zi myprog
tlink /v myprog
td myprog

.COM and .EXE files

The .COM code file format is a relic of the first version of MS-DOS
Not recommended for general purposes
All code, data, and the stack occupy one 64K segment (Borland's "tiny" model)
.EXE code files are more efficient in use of RAM
Data and code occupy separate segments
The programmer is responsible for setting up the data and code segments properly

Ending a Program

All programs, upon termination, must return control back to another program -- the operating system
Under MS-DOS, this is COMMAND.COM
This is done by doing a DOS system call

Data Transfer Instructions

MOV destination,source

reg, reg
mem, reg
reg, mem
mem, immed
reg, immed

Sizes of both operands must be the same
reg can be any non-segment register except IP cannot be the target register
MOV's between a segment register and memory or a 16-bit register are possible

Examples

mov ax, word1

"Move word1 to ax"
Contents of register ax are replaced by the contents of the memory location word1

xchg ah, bl

Swaps the contents of ah and bl

Illegal: mov word1, word2

can't have both operands be memory locations

Sample MOV Instructions

b db 4Fh
w dw 2048

mov bl,dh
mov ax,w
mov ch,b
mov al,255
mov w,-100
mov b,0

When a variable is created with a define directive, it is assigned a default size attribute (byte, word, etc)
You can assign a size attribute using LABEL

LoByte LABEL BYTE
aWord DW 97F2h

Addresses with Displacements

b db 4Fh, 20h, 3Ch
w dw 2048, -100, 0

mov bx, w+2
mov b+1, ah
mov ah, b+5
mov dx, w-3

Type checking is still in effect
The assembler computes an address based on the expression
NOTE: These are address computations done at assembly time

MOV ax,b-1
will not subtract 1 from the value stored at b

eXCHanGe

XCHG destination,source

reg, reg
reg, mem
mem, reg

MOV and XCHG cannot perform memory to memory moves
This provides an efficient means to swap the operands

No temporary storage is needed
Sorting often requires this type of operation
This works only with the general registers

Arithmetic Instructions

ADD dest, source
SUB dest, source
INC dest
DEC dest
NEG dest

Operands must be of the same size
source can be a general register, memory location, or constant
dest can be a register or memory location

except operands cannot both be memory

ADD and INC

ADD is used to add the contents of

two registers
a register and a memory location
a register and a constant

INC is used to add 1 to the contents of a register or memory location

Examples

add ax, word1

"Add word1 to ax"
Contents of register ax and memory location word1 are added, and the sum is stored in ax

inc ah

Adds one to the contents of ah

Illegal: add word1, word2

can't have both operands be memory locations

SUB, DEC, and NEG

SUB is used to subtract the contents of

one register from another register
a register from a memory location, or vice versa
a constant from a register

DEC is used to subtract 1 from the contents of a register or memory location
NEG is used to negate the contents of a register or memory location

Examples

sub ax, word1

"Subtract word1 from ax"
Contents of memory location word1 is subtracted from the contents of register ax, and the sum is stored in ax

dec bx

Subtracts one from the contents of bx

Illegal: sub byte1, byte2

can't have both operands be memory locations

Type Agreement of Operands

The operands of two-operand instructions must be of the same type (byte or word)

mov ax, bh ;illegal
mov ax, byte1 ;illegal
mov ah,'A' ;legal -- moves 41h into ah
mov ax,'A' ;legal -- moves 0041h into ax

Translation of HLL Instructions

B = A

mov ax,A
mov B,ax

memory-memory moves are illegal

A = B - 2*A

mov ax,B
sub ax,A
sub ax,A
mov A,ax

Program Segment Structure

Data Segments

Storage for variables
Variable addresses are computed as offsets from start of this segment

Code Segment

contains executable instructions

Stack Segment

used to set aside storage for the stack
Stack addresses are computed as offsets into this segment

Segment directives

.DATA
.CODE
.STACK size

Memory Models

.Model memory_model

tiny: code+data <= 64K (.com program)
small: code<=64K, data<=64K, one of each
medium: data<=64K, one data segment
compact: code<=64K, one code segment
large: multiple code and data segments
huge: allows individual arrays to exceed 64K
flat: no segments, 32-bit addresses, protected mode only (80386 and higher)

Program Skeleton

.MODEL small
.STACK 100h
.DATA

;declarations

.CODE
MAIN PROC

;main proc code
;return to DOS

ENDP MAIN
;other procs (if any) go here
end MAIN

· Select a memory model

· Define the stack size

· Declare variables

· Write code

· organize into procedures

· Mark the end of the source file

· define the entry point

Input and Output Using 8086 Assembly Language

Most input and output is not done directly via the I/O ports, because

port addresses vary among computer models
it's much easier to program I/O with the service routines provided by the manufacturer

There are BIOS routines (which we'll look at later) and DOS routines for handling I/O (using interrupt number 21h)

Interrupts

The interrupt instruction is used to cause a software interrupt (system call)

An interrupt interrupts the current program and executes a subroutine, eventually returning control to the original program
Interrupts may be caused by hardware or software

int interrupt_number ;software interrupt

Output to Monitor

DOS Interrupts : interrupt 21h

This interrupt invokes one of many support routines provided by DOS
The DOS function is selected via AH
Other registers may serve as arguments

AH = 2, DL = ASCII of character to output

Character is displayed at the current cursor position, the cursor is advanced, AL = DL

Output a String

Interrupt 21h, function 09h

DX = offset to the string (in data segment)
The string is terminated with the '$' character

To place the address of a variable in DX, use one of the following

lea DX,theString ;load effective address
mov DX, offset theString ;immediate data

Print String Example

%TITLE "First Program -- HELLO.ASM"
        .8086
        .MODEL   small
        .STACK   256
        .DATA
msg     DB      "Hello, World!$"
        .CODE
MAIN    PROC
        mov     ax,@data     ;Initialize DS to address
        mov     ds,ax        ; of data segment
        lea     dx,msg       ;get message
        mov     ah,09h       ;display string function
        int     21h          ;display message
Exit:   mov     ah,4Ch       ;DOS function: Exit program
        mov     al,0         ;Return exit code value
        int     21h          ;Call DOS. Terminate program
MAIN    ENDP                 ;End of program
        END     MAIN         ; entry point

Input a Character

Interrupt 21h, function 01h
Filtered input with echo

This function returns the next character in the keyboard buffer (waiting if necessary)
The character is echoed to the screen
AL will contain the ASCII code of the non-control character

AL=0 if a control character was entered

An Example Program

%TITLE "Case Conversion"
    .8086
    .MODEL small
    .STACK 256
    .DATA
MSG1     DB 'Enter a lower case letter: $'
MSG2     DB 0Dh,0Ah,'In upper case it is: '
CHAR     DB ?,'$'
exCode   DB 0
    .CODE
MAIN    PROC
;initialize ds
    mov     ax,@data     ; Initialize DS to address
    mov     ds,ax        ; of data segment
;print user prompt
    mov     ah,9         ; display string fcn
    lea     dx,MSG1      ; get first message
    int     21h          ; display it
;input a character and convert to upper case
    mov     ah,1         ; read char fcn
    int     21h          ; input char into AL
    sub     al,20h       ; convert to upper case
    mov     CHAR,al      ; and store it
;display on the next line
    mov     dx,offset MSG2 ; get second message
    mov     ah,9         ; display string function
    int     21h          ; display message and upper case
;return to DOS
Exit:
    mov     ah,4Ch       ; DOS function: Exit program
    mov     al,exCode    ; Return exit code value
    int     21h          ; Call DOS. Terminate program
MAIN ENDP
    END     MAIN        ; End of

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English Group Assignement-Semester 1

2018-03-30T09:41:00.002-07:00

PREFERANCE OF ENGLISH WORDS OVER AVAILABLE

URDU WORDS: A FACT OR AN ASSUMPTION.

Language is one of the most powerful sourcesof ideology. Each nation has its own ideological boundaries in which language has a significant role.A person must know something of the structure of his language ,its position in the word and its relation to another tongues History shows that many ideological movements used the power of language to succeed. In 21st century where science is pacing up advancement in human life, language still holds its importance for the growth of powerful ideas. Without the progress of language a group of people, a society or a nation can’t represent itself object.

The sum totality of ideas, values, beliefs, attitudes, prejudices, myths, religious strictures, and all the other cultural `baggage' that speakers bring to their dealings with language from their culture. Linguistic culture also is concerned with the transmission and codification of language and has bearing also on the culture's notions of the value of literacy and the sanctity of texts. And of course language itself is a cultural artifact and must be counted as a part of linguistic culture.

English is the most dominant language of the 21st century.It is spreading all around the world and also it is adapting vocabulary from other languages.It is globalized and its major demand is in developed countries.It has taken too much change in our daily routine. Most people in Pakistan prefer to use English words instead of Urdu words in their daily routine.They consider this language as a way to belong to well-educated society, the way towards a better education, better job opportunities etc.Furthermore it is a language used everywhere in the world.Pakistan has a large population of people that can speak or can communicate in English. Almost 50% of Pakistan’s population can speak some level of English. Uses of English words have now become a compulsory thing in our society and are been frequently used in Pakistan.

It is a fact that in our culture and environment, english language has penetrated so much that every person tries to use one or two english words in his speech or conversation. It is our nature that we learn different languages for the sake of interest, fashion and other needs. Our national language is urdu, but we want to influence or impress others by english language, to show others that I have good communication skills. Even the persons, who don’t know about english language and can’t speak english, are also using some english words considering it relevant for their acceptance in the society. There are a lot of people who don’t speak urdu language even in their homes, because they consider it shameful to use urdulanguage.Society also have set the standard that a person who can’t speak english is considered to be illiterate.Samuel Daniel in his poem "Musophilies",wrote in 1959.

And who in time knows whither we my vent

The treasure oourtongue, to what strange

This gain of our best glory shall be sent,

To rich unknowing nations without stores?

Which worlds in the yet unformed Occident

May come refined with the accents that are ours. (74)

English words have been widely used by us or communication with foreigners. When people from foreign countries come to visit Pakistan, they are basically promoting their culture. They use their native language, they don’t hesitate to speak their inborn language even we don’t understand them. When people came from china, they speak Chinese only; some of them can speak little English. Similarly, natives of the France, still speak French. Similarly, when we go abroad they speak their native language only. All countries of the world consider their native language as a pride, because it gives them unique identity. In our country, if we speak Urdu in conversation, we also use many English words with Urdu. It is due to the concept of westernization that is promoted so much in our society that we hesitate to use our national language. We can also say that globalization is also the key factor of promoting this western culture in our language. It is right to say that we cannot survive without English.Mr Rushdie has stated:

What seems to be happening is that those peope who were once colonized by the language are now rapidly remarking it ,domesticating it, becoming more and more relaxed about the way they use it assisted by the English language's enormous flexibility and size, they are carving out large territories for themselves within its frontiers.(5)

The language of science is English and is the second languages of most of the countries including Pakistan. Urdu being less updated and mostly containing outdated content and vocabulary has no part in scientific research.Pakistan is in the list of low progressive countries.Technology induced in market and scientific societies have manufacturing details, blue prints in English language language.UK and other foreign countries are very up to date in many aspects of science and technology. On the other hand, wedon’t have words as meanings of those technologies in our language.Pakistan is not considered a very progressive country in all aspects of science especially in technology. So we borrow those words in our daily use. As soon as a product/entertainment media is launched in the market, other countries including India translate it to the national language of state as to make people use the national language instead of the foreign language. In this way all types of latest technology is in English. Such as websites, communication and social apps, games and all programming languages are in English. Moreover all the latest machinery understands commands only in English language. So English is considering as an essential component for the progress of Pakistan. In this manner Urdu is not updated regularly and is one of the main cause of preference of English words on Urdu

In our education system, we have all the subjects even they are related to science or math are in english.Now mostly students study science subjects in English because it has much in the future.All the Universities have provided their course subjects in English except of subjects like Urdu and Islamiyat.It helps the students to collect research material for their projects and assignments from the internet .Otherwise it will become difficult for the students to research in Urdu language. In Arab and other countries such as China, Japan and Russia, all teaching and research material is presented in their national languages but our Government is not willing to transfer or translate our science and technology material into Urdu.Thats why students prefer to study science subjects in English.

English has huge economic values.It has become a source of livelihood for many people in Pakistan. With the help of English language, they can deal internationalmarkets. Even in Government sector, English is preferred on jobs and deals. The world has progressed so much that it has become necessary for everyone to be uptodate.English is essential for communication not only for Pakistan but also important for other countries. People in Pakistan have to polish their English skills to challenge the Western Countries.If a Pakistani go for a job to countries like America,England ,he has to learn English to earn his livelihood because it is impossible for him to stay without any knowledge of English Language. So we can say that English has become an international language for almost all countries. In this way we can say that in order to successfully communicate with countries; a person has to focus on his knowledge of English words.

English language is now recognized as a Modern language and has earned a status "A language of upper class society".Because of frequent use of English language in elite class, other languages are struggling to survive at official level.In high class societies,Urdu is thought to be a language of lower or middle class people.Youngsters generally used to speak English words instead of Urdu words because they think that speaking English is Modern and has become a fashion amongst them.English has putted a lot of impact on Urdu words .A lot of English words have been written in Urdu language are pronounced as same in English language.Their are different words in like doctor,bedroom,basket,ball are written in Urdu language and have the same pronunciation as they have in English Language. Mr. Crystal has stated "This is the first time we actually have a language spoken genuinely by every country in the world."(11)

There is also a lot of research and knowledge available in English language. Almost every scientific knowledge is available in English language. A lot of moral and spiritual research is also present in English language. If a student is familiar to the English language then he can learn everything easily. Because almost all type of research is available in English language. If a student stuck in solving any complex math problem then he can easily search the solution of that problem from Google. But in order to do this, he has to be familiar to the use of English. He cannot do this by using Urdu or Punjabi words. He can understand not only math but he can understand any subject if he is familiar to English language. So in order to enhance ones knowledge, he has to learn English properly.

Different social events and seminars are arranged in Pakistan in which the Political Leaders emphasize on the use of our national language "Urdu".They try to promote Urdu language but they didn’t perform their role effectively. They advise people in their speeches to speak and learn Urdu but they themselves speak at least one or two words of English in every sentence while addressing to the nation or during any media talk.Inspite of using Urdu words ,they use English words because it gives a pleasant effect on their speech. They wanted to be a good English speaker. Our political leaders including president and prime minister should address official events within or outside the country in Urdu .Also in our schools and colleges, seminars are arranged in which announcements and debates are presented in English language.

Urdu since independence has been declared the national language of the state Pakistan.But the value of Urdu has been the same as it was before independane.Beforeindependence Hindi and English were the dominating languages of the subcontinent and Urdu was one of the minor yet progressing languages of the region.Persion(Farsi) has a major role in the development of Urdu.From the day of independence to the present day Urdu has not progressed as much as the other languages have done in the same period.New words and phrases are not updated as the current need of language.This lack of language updating and not improving the vocabulary results in other languages dominating the language .

As we have discussed much about the importance of English, but it doesn,t means that Urdu has been neglected .Urdu words have their own importance in the society. Basically,Urdu is our mother tongue.Mother tongue is the best way of expression of intellectual powers and mental qualities.Urdu is the unique carrier of our emotional and reasoningactivities.It opens new ways for us to acquire and understand the importance of social maturity and logical thinking.The advancement of Urdu in current Pakistan is necessary for the objectives of a welfare state.As we all know that Pakistan has a great asset in form of Urdu language which can defend the nation on its ideological borders. We must remember the history of this language which had given us the power to make our beloved homeland.SirSapru has stated:"Urdu is a sacred heritage which the Hindus and the Muslims have inherited from their forefathers and it is indivisible"

It is a fact that Urdu is the best way of our expression.It is a language of our jokes, friendships and feeling ease among our community.Love for national language is the sign of developed nations. It must maintain its image as a carrier of progressive thinking, ideology and logical activity.Through it we can secure our cultural heritage and golden traditions .We can shape many progressive minds in the field of science and arts.As the use of English words is increasing day by day but our mother-tongue has penetrated so much in our souls that no other language can take its place.

Urdu has also played an important role in our ideology.Urdu language was used as one of the factors for the demand of Pakistan. A large number of Muslims of India had considered Urdu as their language instead of Hindi, which paved the way for the origin of “Two Nation Theory”."Ideologies are threatened when there is shift from language and cultures.English would not the yard stick to measure caliber for job seeking" (Rehman 1996:242) .Urdu language has vital role in the ideology of Pakistan. The advancement of Urdu in current Pakistan is necessary for the objectives of a welfare state. But Urdu language is facing many challenges in Pakistan. Many regional languages are also in danger to some extent. Because of frequent use of English language in elite class, other languages are struggling to survive at official level. As we all know that Pakistan has a great asset in form of Urdu language which can defend the nation on its ideological borders. We must remember the history of this language which had given us the power to make our beloved homeland. Mr.Rehman has stated:

Language has been initimately related to ideology and power in Pakistan.While Urdu is conspicuous as a symbol of Pakistani identity and national integeritation,otherethnic groups have this as a version of internal colonialism.Indigenous languages thus become tools that serve to assert ethnic identity and ensure a wider mobalisation.(4556)

After Pakistan was given independence there were pro-English, pro-Urdu and pro-ethno-nationalists lobby which shaped our language dispute. After independence, Pakistan underwent a series of political instabilities and marshal laws after which English emerged as the dominant language despite the efforts of the ruling elite of Pakistan and pro-Urdu lobby to give Urdu the status of the national language. The Pro-Urdu lobby failed to run a successful campaign in support of Urdu. The only success they had were the following two clauses were included in article 251 of the constitution of 1973 which is still in place till today.

(1) The National Language of Pakistan is Urdu, and arrangements shall be made for Urdu to be used for official and other purposes within fifteen years.

(2) Subject to clause (1) the English language may be used for official purposes until arrangements are made for the replacement of English.

Although the article proclaimed the national language to be Urdu. Yet till this date clause (2) wasn’t implemented to its full extent.

In the era of Zia’s marshal law steps were taken to make Urdu as a language of instruction and language of administration but these steps were strongly opposed by the pro-English lobby which were mainly the middle and upper class. But by the end of his era Zia realized the completely removing English was an impossible task and he himself admitted that it couldn’t be done.After many more governments and one marshal law later in 2017 English is now consider as co-national language of Pakistan along side Urdu. After 70 years of independence somewhere in-between it all went wrong and the Urdu-English dispute became politicized and became a fight between the elites and the non-elites. As Mr. Rehman states:

During the forty-six years of Pakistan's independence, Urdu has been supported at the rhetorical levels by the ruling elites of Pakistan in order to counter ethno-nationalist sentiment and to increase the power base of the elite. The Urdu proto-elite, which was not allied to the ethno-nationalist proto-elites, supported Urdu, too, as a symbol of Pakistani identity…….. The ruling elite, however, actually supported English for use in all official domains so as to ensure its cultural predominance and distinction from the non-elites; to facilitate the entry of its children in positions of power and privilege and open the possibility of entering the international, very highly paid, professional elite (The Urdu-English controversy in Pakistan 203)

In order to secure Urdu, we must produce and preseve the picelessgift.It is our most prestigious heritage .In order to presereit,we have to make all our efforts by ourselves and the best means to promote and secure Urdu are the books.Thanks to computer that we are now having access to all the calligraphies.Now every computer with an addition of a software , can poduce all our literature in nastaliq(Urdu).We should activte all book producing agencies and also new ones where it is necessary and that must be done by full passion.It is the need of the hour to publish Urdu translations of scientific and technical books available in English.These are essential for our artisans,skilled workers and technological experts who want to improve thei skills.

We must take some steps at National level to promote Urdu language. Some steps are taken by the government officials in promoting Urdu. The Supreme Court of Pakistan recently passed an order in which Supreme Court ordered the Federal Government and Provincial government to use Urdu as official language in country. In its decision it wrote that English cannot be understood by the large number of people in the Pakistan. Notice boards in public offices like police stations, parks, hospitals and banks should display information in Urdu. Urdu can also be promoted by increasing the literacy rate of the countries where Urdu is spoken. It is the duty of every individual to perform its role in developing Urdu language. We should take positive steps to rebuild our national language. We should spread the awareness that Urdu language is also developed language. Love with our national language is sign of love with our country. If we want to become a strong and developed nation and country than we have to adopt our language in all fields. We should guide our elite class societies to use Urdu language. In this way, we shall be successful to write our name in history as successful nation.

References

1. Rahman,Tariq.Language ,Power and Ideology.Economic and Political Weekly,2002.

2. Latifi,Daniel.PreservingUrdu through Self Help.Economic and Political Weekly,1999.

3. Jussawal,Feroza.The Decline of English.National Council of Teachers of English,1982.

4. Crystal ,David.English has a Global Language.CAMBRIDGE.

5. Rehman,Tariq.The Urdu-English Controversy in Pakistan. Cambridge University Press,1997.

6. Russel ,Ralph.Urdu in India Since Independence.Economic and Political Weekly,1999.

7. JitLal,Inder.A language of Composite Culture.Sahitya Akademi,1976.

8. Bikramjit.Abuse of Urdu.Economic and Political Weekly,2004.

9. Neglect of Urdu.Economic and Political Weekly,1985.

10. S.Dulai,Surjit.Urdu POETRY AND ITS ADVENT IN English.Asian Studies Center,Michigan State University,1974.

11. www.britishcouncil.org

Arrays-Assembly Language

2018-03-30T09:33:00.001-07:00

Prepared by: Saad Aslam

Arrays

A one-dimensional array is an ordered list of elements, all of the same type.
To define an array in assembly language

W dw 10,20,30,40,50,60

The address of the array variable is called the base address of the array
If the offset address of the array is 0200h, the array looks like this in memory:

element   offset address   symbolic address contents
W[0]         0200h             W            10
W[1]         0202h             W+2h         20
W[2]         0204h             W+4h         30
W[3]         0206h             W+6h         40

The DUP Operator

Arrays whose elements share a common initial value are defined using the DUP pseudo-op
It has the form:

repeat_count DUP (value)

gamma dw 100 DUP(0)

sets up an array of 100 words, with each entry initialized to 0

delta db 212 DUP(?)

sets up an array of 212 uninitialized bytes

Location of Array Elements

The address of an array element may be computed by adding a constant to the base address
If A is an array and S denotes the number of bytes in an element, then the address of element A[i] is A + i*S (assuming zero-based arrays; for one-based arrays it would be A + (i-1)*S)
To exchange W[9] and W[24] in an word array W:

mov ax,W+18     ; ax has W[9]
xchg W+48,ax     ; ax has W[24]
mov W+18,ax     ; complete exchange

Addressing Data in Memory

Three forms:

Immediate data -- stored directly in machine code

example: mov ax,5 ; 5 is an immediate value
immediate operands are always source operands

example: add ax,bx

Memory data -- held in memory

processor calculates the 16-bit effective address

Memory-Addressing Modes

Direct             mov ax, count
Register-indirect  mov ax, [bx]
Base               mov ax, [record + bp]
Indexed            mov ax, [array + si]
Base-indexed       mov ax, [recordArray + bx + si]
String             lodsw
I/O Port           in ax, dx

Segment Override

Register indirect mode references for bx, si, or di are usually relative to ds
To change this, use a segment override:

mov ax, es:[bi]

Segment overrides can also be used with based and indexed modes.
An override occupies a byte of machine code which is inserted just before the affected instruction

Register-Indirect Mode

The offset address of the operand is contained in a register
The register acts as a pointer to the memory location
The operand format is

[register]
The register is bx,si,di, or bp

For bx,si, ordi, the segment register is ds
For bp, ss has the segment number

Example

si = 0100h, [0100h] = 1234h
To execute mov ax,[si] the CPU

examines si and obtains the offset address 0100h
uses the address ds:0100h to obtain the value 1234h
moves 1234h into ax

This is not the same as mov ax,si which simply moves the value of si (0100h) into ax

Another example

bx=1000h, si=2000h, di=3000h, [1000h]=1BACh, [2000h]=20FEh, [3000h]=031Dh

instruction    source offset     result
mov bx,[bx]     1000h             1BACh
mov cx,[si]     2000h             20FEh
mov bx,[ax]     illegal source register
add [si],[di]   illegal memory-memory add
inc [di]        3000h             031Eh

Processing Arrays using Register-Indirect Mode

Sum in ax the 10-element word array W

W dw 10,20,30,40,50,60,70,80,90,10

xor ax,ax     ; ax holds sum
lea si,W      ; si points to array W
mov cx,10     ; cx has number of elements

addnos:

add ax,[si]   ; sum = sum + element
add si,2      ; move pointer to the next element
loop addnos    ; loop until done

WORD and BYTE PTR operators

Both operands of an instruction must be of the same type

mov ax,1 is a word operation because ax is a 16-bit register
mov bh,5 is a byte operation
mov [bx],1 is illegal because the assembler can't tell whether the destination is a byte or a word

if you want the destination to be a byte, use

mov BYTE PTR [bx],1

and if you want it to be a word, use

mov WORD PTR [bx],1

The LABEL Pseudo-op

We have seen the use of the WORD and BYTE pseudo-ops to remove type ambiguity
The LABEL pseudo-op is another way of working with data of various types
Example:

money   LABEL   WORD
dollars db 1Ah
cents   db 52h
        mov ax,money    ;al=dollars, ah=cents
has same effect as
        mov al,dollars
        mov ah,cents

Based and Indexed Addressing Modes

The operands offset address is obtained by adding a number called a displacement to the contents of a register
The displacement may be:

the offset address of a variable, e.g., A
a constant, e.g., -2
the offset address of a variable plus or minus a constant, e.g., A + 4

Syntax of an operand

Any of the following expressions are equivalent:

[register + displacement] <--- preferred form
[displacement + register]
[register] + displacement
displacement + [register]
displacement[register]

The register must be bx, bp, si, or di.
If bx, si, or di is used, ds contains the segment number
If bp is used, ss has the segment number
The addressing is called based if bx or bp is used; it is called indexed if si or di is used

Application of Index Mode

Replace the lowercase letters in the string to uppercase using index addressing mode

msg db   "this is a message"
     mov cx,17         ; # chars in string
     xor si,si         ; si indexes a char
top:
     cmp [si+msg],' ' ; blank?
     je   next          ; yes, skip over
     and [si+msg],0DFh ; no, convert to upper
next:
     inc si            ; index next byte
     loop top           ; loop until done

Processing Arrays using Based Addressing Mode

Sum in ax the 10-element word array W using based mode

W dw 10,20,30,40,50,60,70,80,90,10

    xor ax,ax     ; ax holds sum
    xor bx,bx     ; clear base register
    mov cx,10     ; cx has number of elements
addnos:
    add ax,[bx+W] ; sum = sum + element
    add bx,2      ; index next element
    loop addnos    ; loop until done

Base-Indexed Addressing Mode

In this mode the offset address is the sum of:

the contents of a base register (bx or bp)
the contents of an index register (si or di)
optionally, a variable's offset address
optionally, a positive or negative constant

There are many valid ways to write the operand, some of them are:

[base + index + variable + constant]<-- preferred
variable[base + index + constant]
constant[base + index + variable]

Use of Based, Indexed, and Base-Indexed Modes

Based and indexed addressing mode is often used for array and string processing
Based-indexed addressing mode can be used for two dimensional arrays
We will discuss these in greater detail later

LEA vs. MOV

lea ax,data

and

mov ax,offset data

do the same thing, but the mov is more efficient

However,

lea bx,[A + si]

is more efficient than

mov bx, offset A
add bx, si

Two-Dimensional Arrays

A 2D array is an array of arrays
Usually view them as consisting of rows and columns

A[0,0] A[0,1] A[0,2] A[0,3]
A[1,0] A[1,1] A[1,2] A[1,3]
A[2,0] A[2,1] A[2,2] A[2,3]

Elements may be stored in row-major order or column-major order

Locating an Element in a 2D Array

A is an M x N array in row-major order, where the size of the elements is S
To find the location of A[i,j]

find where row i begins
find the location of the j^th element in that row

Row 0 begins at location A -- row i begins at location A + i*N*S
The j^th element is stored j*S bytes from the beginning of the row
So, A[i,j] is in location A+(i*N + j)*S

2D Arrays and Based-Indexed Addressing Mode

Suppose A is a 5x7 word array stored in row-major order. Write code to clear row 2.

    mov   bx,28            ; bx indexes row 2
    xor   si,si            ; si will index columns
    mov   cx,7             ; # elements in a row

clear:

    mov   [bx + si + A],0 ; clear A[2,j]
    add   si,2             ; go to next column
    loop clear            ; loop until done

Another Example:

Write code to clear column 3 -- Since A is a 7 column word array we need to add 2*7 = 14 to get to the next row

        mov   si,6            &n bsp; ; si indexes column 3
        xor   bx,bx             ; bx will index rows
        mov   cx,5            &n bsp; ; #elements in a column
clear:
        mov   [bx + si + A],0   ; clear A[i,3]
        add   bx,14             ; go to next row
        loop clear             ; loop until done

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DLD: Laws of Boolean Algebra

2018-03-30T07:54:00.000-07:00

Prepared by:Saad Aslam

Boolean Operations and Expressions

Boolean Algebra is the mathematics of digital system .A basic knowledge of Boolean Algebra is the study and analysis of logic circuits .Variables and complements terms are used in this chapter.

A variable can have a 1 or 0 value.

A complement is the inverse of the variable indicated by a bar over the variable .For example:

Complement of variable A is A.If A is 0 the A is 1 and if A is 1 then A is 0.The complement of a variable is read as “not A” or “A bar”.

Laws and Rules of Boolean Algebra

Laws of Boolean Algebra:

The basics Laws of Boolean Algebra are as follows:

· Commutative Laws

· Associative Laws

· Distributive Laws

Commutative Laws

For addition

A+B=B+A

The figure below illustrates the Commutative law as applied to OR gates.

For Multiplication

AB=BA

The figure below illustrates the Commutative law as applied to AND gates.

Associative Laws

For Addition

A+(B+C)=(A+B)+C

The figure below illustrates the Associative law as applied to OR gates.

For Multiplication

A(BC)=(AB)C

The figure below illustrates the Associative law as applied to AND gates.

Distributive Laws

A(B+C)=AB + BC

The figure below illustrates the Distributive Law by using both AND ,OR gates.

Rules of Boolean Algebra:

Basic rules that are useful in manipulating and simplifying Boolean Expressions are as follows:

Rule 1: A+0=A

A variable ORed with 0 will always equal to the variable.

Rule 2 :A+1=1

A variable ORed with 1 will always equal to 1.

Rule 3 : A.0=0

A variable ANDed with 0 will always equal to 0.

Rule 4: A.1=A

A variable ANDed with 1 will always equal to variable.

Rule 5: A+A=A

A variable ORed with itself will always equal to the variable.

Rule 6: A+A=1

A variable ORed with the complement of itself will equal to 1.

Rule 7: A.A=A

A variable ANDed with itself will always equal to the variable.

Rule 8: A.A=0

A variable ANDed with the complement of itself will always equal to 0.

Rule 9 : A =A

A variable by complementing itself twice will equal to the variable.

Rule 10: A+ AB=A

Proof

A+AB=A(1+B) Distributive Law

=A.1 Rule 2 (1+B=1)

=A Rule 4 (A.1=A)

Rule 11 : A+AB=A+B

Proof

A + AB= (A+AB)+ AB Rule 10 A+ AB=A

= (AA+AB)+ AB Rule 7 A.A=A

= AA+AB+AA+ AB Rule 8 A.A=0

=(A+A)(A+B)

=1.(A+B) Rule 6 A+A=1

=A+B Rule 4 A.1=A

Report Writing-Communication Skills

2018-03-30T02:54:00.001-07:00

COMPUTER SCIENCE:

A Platform for turning Imaginations into Reality

________________________________________________________________

July 19, 2017.

Prepared for:

Sir Sheryar

Prepared by :

Saad Aslam

Roll no: 0043-BSCS-16

Department of Computer Science

Governement College University, Lahore

Table of Contents

Executive Summary………………………………………………………….

1. Introduction………………………………………………………………………. 5

1.1. Background

1.2. Statement of the Problem

1.3. Purposes of the Study

1.4. Scope

2. Related Literature………………………………………………………………. 6

3. Procedure……………………………………………………………………………. 6

4. Findings……………………………………………………………………………….. 7

4.1. Computer Science role towards success

4.2. User perceptions on computing facilities

4.3. Researches made in field of Computer Science

4.4. Employment

5. Analysis................................................................................................................. 9

6. Conclusions and Recommendations................................................... 10

6.1. Conclusions

6.2. Recommendations

Appendix-Study Questionnaire

Bibliography

LIST OF ILLUSTRATIONS

FIGURES

i. Branches of Science……………………………………………… 7

ii. User Perceptions……….…………………………………………..8

iii. Learning Computer Science......…………………………………….9

TABLES

i. Solutions of the Problems…………………………………………..8

EXECUTIVE SUMMARY

Computer science is the most growing fields nowadays. It has taken much more positive change in the world. This study was designed to describe that how computer science proved as a platform for turning imaginations into reality, its progress in the modern world, the researches made in this field .100 students ,teachers and parents entering the GCU Computer Science Department were interviewed. Proper analysis was done on this study and recommended improvements to ensure the progress of this field .

Related Literature shows that computer science is changing, in relation to other sciences and to the human society etc. Computer science should not be viewed only as a human created tools discipline that provides hardware, software and services to other disciplines. Computing is more universal and fundamental. Computation is inherent in nature and in the human society. Further Researches shows that Inovations in computing contributes towards economic growth. Since 1995, networking and other information technology industries accounted for 25 percent of the U.S. economic growth.

A survey revealed that Computer Science is contrinuting 41% towards success and achievements made in this modern world. Users are satisfied with the facilities provided to them by the latest computing techniques and are enjoying these luxuries in their daily life. Above 45% of teachers and students are considering computer science as a field that is providing most solutions to the challenging problems in their work.From 60-80 % of students and teachers are willing to learn computer science.

In addition,the survey shows that students are considering computer science as compulsory study to get employed and to get a job in their future.The urge to learn computer science was found mostly in the male students (above 80%).They are confident are learn confident computer science and to do higher studies in this subject and to make new researches.

The analysis of the study revealed that computer science plays an important role in the progress of the society as compared to other fields of sciences. This field expanded people visions , enhanced their living standards and provided much more facilities in their lives.They consider computer science as a key role towards success .

Based on the conclusions ,it is recommended that Computer Science Department needs to collaborate with other departments to meet up the challenges of the modern world, Researchers and Computer Scientists should be promoted by the government at all levels ,Government should invest more in the field of computer science and free Computer Courses should be started by the Government so that those students, who cannot afford to bear the expenses of this study , can have knowledge about this field.

1. INTRODUCTION

Computer Science is the systematic study of the feasibility, structure, expression, and mechanization of the methodical Processes (algorithms) that underlie the achievement, representation, processing, storage, communication and access to information.

1.1. Background:

In the early years of field, Computer Scientists were primarily concerned with the size, efficiency and reliability of computers. They attempted to increase the computational speed of computer, reduce the physical size and to make it more practical and useful. The research mainly dealt with hardware, programming languages, compilers and operating systems. There were different generations of computer, in which there were modifications in the previous generation computers .With the passage of time, computer science has developed so much that it has now become a gateway to success.

1.2. Statement of the Problem:

The focus of the study is to determine (1) that Computer Science provides a platform for turning imaginations into reality , (2) to make new researches in the field of science and (3) to benefit the humanity to maintain their lifestyle.

1.3. Purposes of the Study:

The purposes of the study are as follows:

i. To provide a description about Computers role in todays world.

ii. To determine if the computing facilities provided to the users are adequate.

iii. To analyze user perceptions about latest technologies in the field of Computer Science.

iv. How Researchers are using advanced computing infrastructure to enhance the quality of life?

v. Why most students are now selecting Computer Science as compared to other branches of science?

vi. To determine new ways to success that Computer Science is providing in the field of science.

vii. To determine that to which extent Computer Science has proved beneficial for the modern world.

1.4. Scope:

This study was limited to the perceptions of students (male,female) ,parents and teachers as to study computer science as a platfrorm for turning imaginations into reality and to which extent it has proved beneficial for the modern world. This study was restricted to Universities and academies. For the purpose of the study ,computer science is a field of science which led the world to new advancements and acted as gateway towards success.

2. RELATED LITERATURE

Advances in computer, communication and information science and engineering have transformed our lives. Essentially all practical applications of information technology are based on ideas and concepts that emerged from investments in basic computing research.

A common observation is that role of computer science is changing, in relation to other sciences and to the human society etc. Computer science should not be viewed only as a human created tools discipline that provides hardware, software and services to other disciplines. Computing is more universal and fundamental. Computation is inherent in nature and in the human society.

Inovations in computing contributes towards economic growth. Since 1995, networking and other information technology industries accounted for 25 percent of the U.S. economic growth. In 2010 alone, information technology industries grew 16 % and contributed 5 % to the overall U.S. gross domestic product.

Beyond contributing towards economic growth, computer science accelerates the pace of discovery and innovation in nearly all fields. Researchers are using advanced computing infrastructure to improve the quality of brain tumor imaging. Advanced tools allow doctors to make more informed decisions about treatment options and perform more successful surgeries. Computing machines like CT Scanners etc are facilitating in the medical field.

3. PROCEDURES

A survey was conducted using sampling technique to ensure randomization in the respondants. It was determined statistically that a sample of 100 students would provide .05 precision and 95% confidence level. The procedures followed included these:

i. A questionnaire was developed that contained simple questions, check list questions , multiple choice questions and open ended questions .

ii. Interviews were conducted by interviewers at GCU Computer Science Department.

iii. Interviews were conducted over a two day period-Monday through Tuesday-beginning on

iv. July 10, 2017.

v. Every 20^th student entering the department was approached for an interview. If the interview was rejected than interview was conducted for the next available student until one was willing to be interviewed.

vi. The data was tabulated using MS-Excel.

vii. The results were analyzed by BSCS student and this report prepared.

4. FINDINGS

These findings are presented using the study objectives as framework. These following sections include information about demographic information describing computer science roll towards success, user perceptions on advanced technologies, researches made in the field of computer science, students review towards computer science, employment and to which extent it has proved beneficial for the modern world.

Computer Science role towards success:

The demographic description for the study-computer science role towards success-provides detailed description. The presentation of these findings is shown in the figure1

This figure shows that Computer Science has made most success as compared to other fields of science.

User Perceptions on Computing Facilities:

Figure2 shows the user perceptions on various computing facilties.The presentations of findings shows that the users are fully satisfied with computing facilities available in todays world.

Figure2:User Perceptions

Researches made in the field of Computer Science:

Researches made in the field of computer science has transformed people lives and has provided them the solutions of their problems.

Table1:Solutions of Problems

Which field of Science provides solutions to the most pressing problems of society?

	Teachers (%)	Male (%)	Female (%)
Computer Science	43	47	39
Physics	25	24	22
Chemistry	20	17	23
Biology	9	10	14	—
Other Sciences	3	2	2

Employment:

Computer science students stand a pretty good chance of being professionally employed or in further study within 6 months from leaving university.Students consider it essential to study computer science because they think that it will help to get a job in the near future.As in figure3 ,it is clealy visible that students are considering computer science important for employment.

Figure3:Learning Computer Science

5. Analysis

The study shows that computer science plays an important role in the progress of the society as compared to other fields of sciences. This field expanded people visions , enhanced their living standards and provided much more facilities in their lives.They consider computer science as a key role towards success .

The study shows that latest computing techniques has provided more luxuries to the society and these facilities are beneficial for them in their daily routine. There is no reason that they can neglect the importance of computer science .It has modeled their brain and well being of people through technology.

In addition, this study shows researches made in the field of computer science are much more vast then the other fields of sciences.It has transformed health care system and has provided latest machinery that has helped people in taking care of their health .

Finally,this study shows clearly that the majority of students even teachers are confident to learn computer science because they know that this field has much vast scope in present and in the near future also.So,they are desperately willing to learn computer science because to get employed they want knowledge of computers.

6. Conclusions and Recommendations

Conclusions:

I. Computer Science has made much more success as compared to other fields of science. It is considered as a step towards a better future.

II. Users are satisfied with the facililties provided to them by this field in the form of latest technologies. Technologies computers, laptops etc are facilitating them in their daily work.

III. Computer Science is a vast field. Researchers have made extraordinary researches that have proved beneficial for the mankind to maintain their health .Researches have been made that have enabled doctors to cure serious diseases like brain tumor.

IV. Students are considering computer science as an important subject to study.They wanted to

Learn computer science because this will help them in their future

V. People are giving much preference to computer science because it has now become a compulsory part for being employed and to compete with others in this fast world.

Recommendations:

We had learned that field of computer science plays a vital role in our society and it is a huge field but this field still need some recommendations through which it might do some new innovations.Some of the recommendations are given below:

i. Computer Science Department needs to collaborate with other departments to meet up the challenges of the modern world and to gain more knowledge about new concepts.

ii. The latest technologies provided by the advanced computing should have complete investigation that whether the facilities provided to the public are adequate or not.

iii. Researchers and Computer Scientists should be promoted by the government at all levels .Government should invest more in the field of computer science.Because Researchers are the one who are working for the progress of this world and for all this mankind.

iv. Research Centers should be increased and their needs should be fulfilled.

v. Computer Science should be given much more preference in our schools.

vi. Free Computer Courses should be started by the Government so that those students, who cannot afford to bear the expenses of this study , can have knowledge about this field.

vii. Proper Training should be given to the employers about computer science in order to get a good performance.

Appendix-Study Questionnaire

Computer Science: A platform for turning imaginations into reality Survey

Hello, I am ___________________ student of BSCS(2016_2020).I am doing a survey on computer science .May I ask you a few questions?

i. Which field of science is progressing more in todays world?

a. Computer Science b. Physics c. Chemistry d. Other fields

ii. Do you think latest computing techniques are adequate?

a. Strongly Agree b. Agree c. Disagree d. Strongly Disagree

iii. Do computers have facilitated people with more luxury?

a. Strongly Agree b. Agree c. Disagree d. Strongly Disagree

iv. Do you think that these facilities are beneficial for the people?

a. Strongly Agree b. Agree c. Disagree d. Strongly Disagree

v. Which field of Science provides solutions to the most pressing problems of society?

a. Computer Science b. Physics c. Chemistry d. Other fields

vi. How confident you are that you could learn computer science if you wanted to do?

a. (0-30)% b.(30-50)% c. (50-70)% d.(70-100)%

vii. How likely are you to learn computer science in the future?

a. (0-30)% b.(30-50)% c. (50-70)% d.(70-100)%

viii. How likely are you that you would have a job someday where you will need to know computer science?

a. (0-30)% b.(30-50)% c. (50-70)% d.(70-100)%

ix. What change has brought Computer Science to the lives of people?

Ans:___________________________________________________________________

Bibliography

Wang, Liauro -“The Future of Computer Science”, Cornell University, Ithaca NY 14853, USA:551-560.

Tapan S,Praikh - “Computer Science and Global Economic Development:

Sounds Interesting, but is it Computer Science?”, UC Berkeley School of Information

Berkeley, CA, USA: 20-40.

Arghya Ray - “Importance of Computer ScienceEducationin the General Social Context” ,(National Computing Academy, 2015).

Zhi-Wei Xu and Dan-Dan Tu- “Three New Concepts of Future Computer Science” , Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100190, China,( December 15, 2010):616-625

“Enhancing our lives through Computing” , National Science Foundation.

Visual Programming Course Outline

2018-03-27T05:03:00.001-07:00

Course Instructor: Ms. Asma Kanwal / Mam Anoosha

Description

Visual programming languages are extensively used for the rapid development of graphical applications. This subject will introduce students to the essential principles of event-driven programming and to programming using a visual environment through the use of the Visual C# programming language.

An important thrust of the course is to teach C# programming from an object-oriented viewpoint. It is often difficult for programmers trained originally in a procedural language to start "thinking in objects."

· .NET Enterprise Architecture

1. NET Framework

2. Base Class Libraries (BCL)

3. Common Language Run Time (CLR)

4. Microsoft Intermediate Language (MSIL)

5. Common Language Specification (CLS)

· Introduction

1. Structure of a C# program

2. Compiling and Executing

3. Commenting

4. Value-Type Data

5. Arrays

6. Reference-Type Data

· Arrays

1. Overview

2. Creating Arrays

3. Command Line Argument

4. Multi-Dimensional Arrays

· Control Statements

1. Introduction

2. Statement Blocks

3. Methods

4. if Statements

5. switch Statement

6. loop Statements

7. break and continue

8. return Statements

More Data Types

1. Structs

2. Interfaces

3. Delegates

4. Enumerations

5. Namespaces

6. Applications and Libraries

C# Concepts

1. Application Startup

2. Member Access

3. Overloading

4. Scope

5. Value vs. Reference Parameters

6. Conversions

7. Exceptions

Classes

1. Object Oriented Programming

2. Simple Class Example

3. Class Methods

4. Constructors

5. Access Levels

6. Other Modifiers

7. Fields

8. Properties

9. Operators

10. Destructors

11. Static Constructor

Inheritance

1. Introduction

2. Base Class Modifiers

3. Direct Inheritance

4. Static vs. non-static

5. Abstract Classes

6. Interfaces

7. Base Class Interfaces

Delegates And Events

1. Overview

2. Delegates

3. Events

Data Streams

1. Introduction

2. Streams

3. Readers

4. Writers

5. File I/O

Properties, Indexers And Attributes

1. Where to use

2. Properties

3. Indexers

4. Attributes

Creating Windows-based Applications

1. Introduction to Windows Forms

2. Visual Studio and the Forms Designer

3. Using Controls

4. List Controls

5. Working with Dialogs

6. Menus, Toolbars and Status Bars

7. Advanced Windows Forms Topics

8. Using Advanced Controls

Using ADO.NET to Access Data

1. ADO.NET Architecture

2. Data Providers in .NET

3. Connection, Command

4. Data reader

5. Data Adapter

6. Data Set

7. Command Builder

8. Data Relations

9. ADO.NET and XML

10. Writing an ADO.NET Application with Windows Forms

Assemblies

1. Private Assemblies

2. Shared Assemblies

3. Global Assembly Cache (GAC)

4. Architecture of CLR

5. Components in CLR

6. Type Safety

Threads

1. Overview

2. Understanding Threads

3. Using Threads in C#

4. Thread Properties

5. Managing Threads

6. Interrupting and Terminating Threads

7. Synchronization

Windows Services

1. Service base class

2. Service Process Installer

3. Service Installer

4. Creating a windows Service

5. Installutil.exe

Window Communication Foundation

1. Introduction to WCF

2. Addresses and Bindings

3. Service Contracts

4. Instance Management

5. Data Contracts

6. More about Service Contracts

7. Handling Errors

Building WEB APPLICATION WITH ASP.NET

1. Understanding Web Application and Web Services

2. The Role of HTML

3. Building Classic ASP Page

4. Interacting with the Incoming HTTP Request and Outgoing HTTP Response

5. Life Cycle of ASP.Net Web page

6. ASP.Net Web Controls

7. The Role of Validation Controls

Recursion- DSA

2018-03-26T07:13:00.006-07:00

By: Gulfam Tahir
Section : E2

Permutation Program through Recursive Call

#include<iostream>

using namespace std;

int punction(int,int);

int fac(int);

int fac(int n){

if(n<=1){

return 1; //base case

}else{

return n*fac(n-1); //recrssive case

}

int punction(int k,int r){

if(k<=1){

return 1; //base case

}

else

{

return (k-r)*fac(k-r-1); //recurssive case

}

int main(){

cout<<"\n\n******************** Permutation *********************"<<endl;

int n,r;

cout<<"\n\nEnter n"<<endl;

cin>>n;

cout<<"enter value of r"<<endl;

cin>>r;

int j=fac(n)/punction(n,r);

cout<<"permutation of "<<n<<"P"<<r<<" "<<"is"<<" "<<j;

}

Differential Equation Mid Term Syllabus

2018-03-22T12:06:00.001-07:00

Classification of Differential Equation
Order and Degree
General Solution
Seperable Equation
Homogenous Equation and Solution
Equation Reducible to Homogenous
Exact Equation
Intergrating Factor
Linear Equation
Orthogonal Trajectories
Bernoulis Equation

Number System-DLD

2018-03-22T09:48:00.000-07:00

Prepared by: Saad Aslam

Number System

Radix or Base a number System:

Base or Radix of number system is the no symbols used in its representations .

For example:

· Decimal number system has 10 symbols

0 ,1 ,2 ,3 ,4 ,5 ,6 ,7 ,8 ,9 hence Radix or Base is 10

· Binary number system has symbols 0 or 1

Therefore radix is 2

· Octal number system has 8 symbols

0 ,1, 2, 3, 4, 5, 6, 7 therefore Rdix or Base is 8

· Hexadecimal number system has 16 symbols

0 ,1 ,2, 3………………..,15 .Therefore Radix is 16

Common Number Systems

System	Base	Symbols	Used by Humans?	Used by Computers?
Decimal	10	0,1,2, . . . . ,9	Yes	No
Binary	2	0 , 1	No	Yes
Octal	8	0 , 1 ,2 , . . . ,7	No	No
Hexadecimal	16	0 ,1,2, . . . ,9 ,A ,B, C , . . ,F	No	No

In general ,a number can be expressed in Base-r system as

a_n rⁿ+ a_n-1r^{n- 1}+ .………………… + a₀r⁰+ a_-1r^-1+ a_-2r^-2+…………………....+ a_-mr^-m

For example:

2 3 4 6 . 5 9

2*10³ + 3*10² + 4*10¹ + 6*10⁰ + 5*10^-1 + 9*10^-2 =2346.59

Types of Number Systems

Commonly used number systems are:

1. Decimal Number System

2. Binary Number System

3. Octal Number System

4. Hexadecimal Number System

Conversion of Bases

1. (A)Decimal number system to other Number Systems

(B) Other Number Systems to Decimal Number Systems

2. (A)Binary number system to other Number Systems

(B)Other Number Systems to Binary Number Systems

3. (A)Octal number system to other Number Systems

(B) Other Number Systems to Octal Number Systems

4. (A)Hexadecimal number system to other Number Systems

(B) Other Number Systems to Hexadecimal Number Systems

1. (A) Decimal to other Number Systems

Decimal to Binary

Q.Convert the decimal 18 to Binary Number System.

2 18

2 9 -- 0

2 4 -- 1

2 2 -- 0

1 -- 0

Note: Binary has two Base “2” so divide 18 by 2.

(18)₁₀=(10010)₂

(1 0 0 1 0)₂

MSB LSB

If there is a fractional value:

Q: Convert the following decimal fraction to binary fraction

· (0.625)₁₀

· (0.18725)₁₀

(0.625)₁₀

If the fractional value is given then you have to multiply by “2” as

Real Part Decimal Point Fractional Part

0.625*2 1 . 25

0.25*2 0 . 50

0.50*2 1 . 00

(0.625)₁₀ = ( . 101)₂

· Do this by yourself (0.18725)₁₀into Binary Number System

Decimal to Octal

Q: Convert the following Decimal to Octal Number System

· (172.878)₁₀

Sol:

First take Real Part 172 and divide by 8

8 172

8 21 -- 4

8 2 -- 5

(254)₈

Now take Fractional Part and Multiply by 8

Real Part Decimal Point Fractional Part

0.878 * 8 7 . 024

0.024 * 8 0 . 152

0.152 * 8 1 . 536

0.536 * 8 4 . 288

Solve upto 4 digits

(0.878)₁₀= ( . 7014)₈

So, (172.878)₁₀ = (254.7014)₈

Decimal to Hexadecimal

Q:Find the value of x

(786.983)₁₀= ( x )₁₆

Sol:

This type of question mean to convert decimal to Hexadecimal

16 786

16 49 – 2

16 3 -- 1

(786)₁₀= (312)₁₆

Real Part Decimal Point Fractional Part

0.983 * 16 15 = F . 728

0.728 * 16 11 = B . 648

0.648 * 16 10 = A . 368

0.368 * 16 5 . 886

(.983)₁₀= (.FBA5)₁₆

So,

(786.983)₁₀= (312.FBA5)₁₆

Q: Convert (82.35)₁₀ to base 4 number system.

Sol:

4 82

4 20 – 2

4 5 -- 0

1 – 1

(82)₁₀= (1102)₄

Real Part Decimal Point Fractional Part

0.35 * 4 1 . 40

0.40 * 4 1 . 60

0.60 * 4 2 . 40

0.40 * 4 1 . 60

(.35)₁₀= (.1121)₄

So,

(82.35)₁₀= (1102.1121)₄

(B) Other Number Systems to Decimal Number Systems

Binary to Decimal

Q : Convert the Binary number 11010.011 to decimal

Sol:

= 1*2⁴ + 1*2³ + 0*2² + 1*2¹ + 0*2⁰ + 0*2^-1 + 1*2^-2 + 1*2^-3

= 16 + 8 + 0 + 2 + 0 + 1/4 + 1/8

= ( 26.375 )₁₀Ans

Octal to Decimal Number System

Q: Convert the following Octal to Decimal Number System

(763.45)₈

Sol:

= 7*8² + 6*8¹ + 3*8⁰ + 4*8^-1 + 5*8^-2

= 7*64 + 6*8 + 3 + 4/8 + 5/64

= (499.5781 )₁₀Ans

Hexadecimal to Decimal Number System

Q: Convert the following Hexadecimal to Decimal Number System

(ABC.75)₁₆

Sol:

= A*16² + B*16¹ + C*16⁰ + 7*16^-1 + 5*16^-2

= 10*256 + 11*16 + 12 + 7/16 + 5/256

= (2748.457 )₁₀Ans

2. (A)Binary number system to other Number Systems

Binary to Octal

Technique

· Group bits in threes ,starting on right before decimal point and from left after decimal point.

· Convert to Octal digits

Q: Convert the following Binary Number to Octal

a)(1011011.011011)₂b)(1101.00101)₂

a)(1011011.011011)₂

sol:

Make 3,3 pairs

001 011 011 . 011 011

1 3 3 . 3 3

=(133.33)₈Ans

b) (1101.00101)₂

001 101 . 001 010

1 5 . 1 5

=(15.15)₈Ans

Binary To Hexadecimal

Technique

· Group bits in fours ,starting on right begore decimal point and from left after decimal point.

· Convert to Hexadecimal digits

Q: (10111011.011011)₂ to ( x )₁₆

Sol:

1011 1011 . 0110 1100

B B . 6 C

=(BB.6C)₁₆

Hexadecimal to Octal Number System

Technique

· Use Binary as Intermediatry

Q:Convert the following hexadecimal to Octal Number System

a) 1A5B b) A246.39

a) 1A5B

Sol: First convert the Hexadecimal to Binary

1 A 5 B

0001 1010 0101 1011

Then making pairs of 3 bits starting from right to left

000 001 101 001 011 011

0 1 5 1 3 3

=(15133)₈

b) A246.39

Do by yourself

Conversion of Any Number System to any other Number System

Technique:

· Convert the first base to decimal, by multiplying with base given and taking powers.

· Then convert the decimal number system to the specified base by dividing with the base

Q:Convert (124)₅ to ( x )₁₂

Sol:

First convert into Decimal

=1*5² + 2*5¹ + 4*5⁰

=25 + 10 + 4

=( 39 )₁₀

Now Perfom the following process with base 12

12 39

3 --- 3

=( 33 )₁₂

Note:

All conversions are described in the above examples . Therefore, part 3 and 4 is not written separately.

Exercise

Convert the following given number system to other number systems

Decimal	Binary	Octal	Hexadecimal
33	?	?	?
?	1110101	?	?
?	?	703	?
?	?	?	1AF

Addressing Modes in 8086

2018-03-21T10:05:00.000-07:00

Prepared by Saad Aslam

Addressing mode indicates a way of locating data or operands. Depending up on the
data type used in the instruction and the memory addressing modes, any instruction may
belong to one or more addressing modes or same instruction may not belong to any of the
addressing modes.
The addressing mode describes the types of operands and the way they are accessed for
executing an instruction. According to the flow of instruction execution, the instructions may be
categorized as
1. Sequential control flow instructions and
2. Control transfer instructions.
Sequential control flow instructions are the instructions which after execution, transfer
control to the next instruction appearing immediately after it (in the sequence) in the program. For
example the arithmetic, logic, data transfer and processor control instructions are Sequential
control flow instructions.
The control transfer instructions on the other hand transfer control to some predefined
address or the address somehow specified in the instruction, after their execution. For example
INT, CALL, RET & JUMP instructions fall under this category.
The addressing modes for Sequential and control flow instructions are explained as follows.
1. Immediate addressing mode:
In this type of addressing, immediate data is a part of instruction, and appears
in the form of successive byte or bytes.
Example: MOV AX, 0005H.
In the above example, 0005H is the immediate data. The immediate data may be 8- bit or 16-bit in
size.
2. Direct addressing mode:
In the direct addressing mode, a 16-bit memory address (offset) directly specified in the
instruction as a part of it.
Example: MOV AX, [5000H].
3. Register addressing mode:
In the register addressing mode, the data is stored in a register and it is referred using the
particular register. All the registers, except IP, may be used in this mode.
Example: MOV BX, AX
4. Register indirect addressing mode:
Sometimes, the address of the memory l o c a t i o n which contains data or operands is
determined in an indirect way, using the offset registers. The mode of addressing is known as
register indirect mode.
In this addressing mode, the offset address of data is in either BX or SI or DI Register. The
default segment is either DS or ES.
Example: MOV AX, [BX].
5. Indexed addressing mode:
In this addressing mode, offset of the operand is stored one of the index registers. DS & ES
are the default segments for index registers SI & DI respectively.
Example: MOV AX, [SI]
Here, data is available at an offset address stored in SI in DS.
6. Register relative addressing mode:
In this addressing mode, the data is available at an effective address formed by adding an
8-bit or 16-bit displacement with the content of any one of the register BX, BP, SI & DI in the default
(either in DS & ES) segment.
Example: MOV AX, 50H [BX]
7. Based indexed addressing mode:
The effective address of data is formed in this addressing mode, by adding content of a
base register (any one of BX or BP) to the content of an index register (any one of SI or DI). The
default segment register may be ES or DS.
Example: MOV AX, [BX][SI]
8. Relative based indexed:
The effective address is formed by adding an 8 or 16-bit displacement with the sum of
contents of any of the base registers (BX or BP) and any one of the index registers, in a default
segment.
Example: MOV AX, 50H [BX] [SI]
For the control transfer instructions, the addressing modes depend upon whether the
destination location is within the same segment or in a different one. It also depends upon the
method of passing the destination address to the processor. Basically, there are two addressing
modes for the control transfer instructions, viz. Inter segment and intra segment addressing modes.
If the location to which the control is to be transferred lies in a different segment
other than the current one, the mode is called intersegment mode. If the destination
location lies in the same segment, the mode is called intersegment mode.
Addressing Modes for control transfer instructions:
1. Intersegment
· Intersegment direct
· Intersegment indirect
2. Intrasegment
· Intrasegment direct
· Intrasegment indirect

1. Intersegment direct:
In this mode, the address to which the control is to be transferred is in a different segment.
This addressing mode provides a means of branching from one code segment to another code
segment. Here, the CS and IP of the destination address are specified directly in the instruction.
Example: JMP 5000H, 2000H; jump to effective address 2000H in segment 5000H.
2. Intersegment indirect:
In this mode, the address to which the control is to be transferred lies in a different
segment and it is passed to the instruction indirectly, i.e. contents of a memory block
containing four bytes, i.e. IP(LSB), IP(MSB), CS(LSB) and CS(MSB) sequentially. The
starting address of the memory block may be referred using any of the addressing modes,
except immediate mode.
Example: JMP [2000H].
Jump to an address in the other segment specified at effective address 2000H in DS.
3. Intrasegment direct mode:
In this mode, the address to which the control is to be transferred lies in the same
segment in which the control transfers instruction lies and appears directly in the
instruction as an immediate displacement value. In this addressing mode, the displacement
is computed relative to the content of the instruction pointer.
The effective address to which the control will be transferred is given by the sum
of 8 or 16 bit displacement and current content of IP. In case of jump instruction, if
the signed displacement (d) is of 8-bits (i.e. -128<d<+127), it as short jump and if it is of 16
bits (i.e. -32768<d<+32767), it is termed as long jump.
Example: JMP SHORT LABEL.
4. Intrasegment indirect mode:
In this mode, the displacement to which the control is to be transferred is in the
same segment in which the control transfer instruction lies, but it is passed to the
instruction directly. Here, the branch address is found as the content of a register or a
memory location.
This addressing mode may be used in unconditional branch instructions.
Example: JMP [BX]; Jump to effective address stored in BX.