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Introduction of C language

2014-12-18T20:59:00.001-08:00

Introduction of C language

'C' is a general purpose, Structured Programming language. It is suitable for solving scientific and engineering problems as well as for business application. Over the past few years, C has become the most popular computer programming language. C's speed and power have always made it a favorite language for operating systems, compilers, interpreters and word processors. Many powerful applications can be generated in C language economically and correctly using C language. C language encourages users to write additional library functions of their own to enhance the features of C language. One of the unique features of C language is that it is available on any make of computer and also available for a range of computers, including mainframe, mini and microcomputers.

Types of languages

As we human beings communicate with each other’s in different language such as English, French, German or Arabic. Similarly to communicate with the computers we have to use specific language and for this purpose hundreds of languages have been invented in which few of them has gained international reputation. C language is one of them. Languages can be can be broadly categorized into three categories.

Machine Language

The most elementary and first type of computer, which was invented, was machine language. Machine language was machine dependent. A program written in machine language cannot be run on another type of computer without significant alterations. Machine language is sometimes referred to as the binary language; i-e, the language of 0 and 1, where 0 stands for the absence of electric pulse and 1 stands for the presence of electric pulse. Very few computer programs are actually written in machine language.

Assembly language

As computer became more popular, it became quite apparent that machine language programming was simply too slow and tedious for most programmers. Assembly languages are also called as low-level language. Instead of using the string of numbers, programmers began using English-like abbreviations to represent the elementary operation. The language provided an opportunity to the programmers to use English like words that were called MNEMONICS.

For Example

LDAA

ADD B

Where

LDAA = Load Accumulator with A

Add B = Add number B to the contents of the accumulator, leaving the result in accumulator.

High level languages

The assembly languages started using English like words, but still it was difficult to learn these languages. High level languages are the computers language in which it is much easier to write a program than the low-level languages. A program written in high-level language is just like giving instruction to person in daily life. It was in 1957 that a high level language called FORTRAN (Formula Translation) was developed by IBM, which was specially developed for Scientists and Engineers. Other high level languages are COBOL (Common Business Oriented Language), which is widely used for business data processing task. BASIC (Beginners All-Purpose Symbolic Instruction Codes), which is developed for the beginners in 1960s. The most powerful and widely used language is C language which is a general purpose programming language. You can use C language for almost any programming task. PASCAL PL/1 are other high level languages, which has gained widespread acceptance.

Explain office automation system and expert system

2014-10-14T01:30:00.000-07:00

Explain office automation system and expert system in detail.

Office Automation System

"Office automation refers to the type of computer machinery and software used to digitally create, collect, store, manipulate, and relay office information needed for accomplishing basic tasks and goals. Raw data storage, electronic transfer, and the management of electronic business information comprise the basic activities of an office automation system."

Generally, there are three basic activities of an office automation system: storage of information, data exchange, and data management. Within each broad application area, hardware and software combine to fulfill basic functions that are needed to successfully accomplish the goals for a specific business. Storage of information would be the computer or a computer like system. Data Exchange would be a fax, phone, or some type of communication hardware. Data management would be using specific software tools to organize and maintain data.

Expert System

A computer application that performs a task that would otherwise be performed by a human expert. For example, there are expert systems that can diagnose human illnesses, make financial forecasts, and schedule routes for delivery vehicles. Some expert systems are designed to take the place of human experts, while others are designed to aid them.

Expert systems are part of a general category of computer applications known as artificial intelligence . To design an expert system, one needs a knowledge engineer, an individual who studies how human experts make decisions and translates the rules into terms that a computer can understand.

What is Normalization Explain 1nf, 2nf, 3nf

2014-10-14T00:58:00.000-07:00

What is Normalization? Explain 1nf, 2nf and 3nf in detail with the help of an example.

Normalization of Database

Database Normalization is a technique of organizing the data in the database. Normalization is a systematic approach of decomposing tables to eliminate data redundancy and undesirable characteristics like Insertion, Update and Deletion Anomalies. It is a multi step process that puts data into tabular form by removing duplicated data from the relation tables.
Normalization is used for mainly two purpose,

Eliminating redundant(useless) data.
Ensuring data dependencies make sense i.e data is logically stored.

Normalization Rule

Normalization rule are divided into following normal form.

First Normal Form
Second Normal Form
Third Normal Form

First Normal Form (1NF)

As per First Normal Form, no two Rows of data must contain repeating group of information i.e each set of column must have a unique value, such that multiple columns cannot be used to fetch the same row. Each table should be organized into rows, and each row should have a primary key that distinguishes it as unique.
The Primary key is usually a single column, but sometimes more than one column can be combined to create a single primary key. For example consider a table which is not in First normal form
Student Table :

Student   Age   Subject
Adam   15   Biology, Maths
Alex   14 Maths
Stuart 17 Maths

Student Table following 1NF will be :In First Normal Form, any row must not have a column in which more than one value is saved, like separated with commas. Rather than that, we must separate such data into multiple rows.

Student	Age	Subject
Adam	15	Biology
Adam	15	Maths
Alex	14	Maths
Stuart	17	Maths

Using the First Normal Form, data redundancy increases, as there will be many columns with same data in multiple rows but each row as a whole will be unique.

Second Normal Form (2NF)

As per the Second Normal Form there must not be any partial dependency of any column on primary key. It means that for a table that has concatenated primary key, each column in the table that is not part of the primary key must depend upon the entire concatenated key for its existence. If any column depends only on one part of the concatenated key, then the table fails Second normal form.
In example of First Normal Form there are two rows for Adam, to include multiple subjects that he has opted for. While this is searchable, and follows First normal form, it is an inefficient use of space. Also in the above Table in First Normal Form, while the candidate key is {Student, Subject}, Age of Student only depends on Student column, which is incorrect as per Second Normal Form. To achieve second normal form, it would be helpful to split out the subjects into an independent table, and match them up using the student names as foreign keys.

New Student Table following 2NF will be :

Student	Age
Adam	15
Alex	14
Stuart	17

In Student Table the candidate key will be Student column, because all other column i.e Age is dependent on it.

New Subject Table introduced for 2NF will be :

Student	Subject
Adam	Biology
Adam	Maths
Alex	Maths
Stuart	Maths

In Subject Table the candidate key will be {Student, Subject} column. Now, both the above tables qualifies for Second Normal Form and will never suffer from Update Anomalies. Although there are a few complex cases in which table in Second Normal Form suffers Update Anomalies, and to handle those scenarios Third Normal Form is there.

Third Normal Form (3NF)

Third Normal form applies that every non-prime attribute of table must be dependent on primary key. The transitive functional dependency should be removed from the table. The table must be in Second Normal form. For example, consider a table with following fields.

Student_Detail Table :

Student_id Student_name DOB Street city State Zip

In this table Student_id is Primary key, but street, city and state depends upon Zip. The dependency between zip and other fields is called transitive dependency. Hence to apply 3NF, we need to move the street, city and state to new table, with Zip as primary key.

New Student_Detail Table :

Student_id Student_name DOB Zip

Address Table :
Zip Street city state

The advantage of removing transtive dependency is,

Amount of data duplication is reduced.
Data integrity achieved.

What is database management system Explain its types

2014-10-14T00:22:00.000-07:00

What is database management system? Explain Network, Hierarchical, Relational Database management system.

Database management system

In database environment the DBMS is the software that provides the interface between the data files and that program that request for user to processing the important data management functions .including

Creating Table
Entering and editing data
Viewing data by using filters and forms
Sorting the records
Querying the database to obtain specific information
Generating reports to print processed information

The Database system like Oracle, informix, sybase.

The DML (Data manipulation Language) is responsible for manipulate the data and DDL (Data Definition Language) describe how the data are stored. DBMS manage the data according to DML required and DDL description.

Hierarchical Database management system

The hierarchical model is the basis of the oldest database management system, since these data base were add as solution to immediate problems, they were created without the strong theoretical foundation that later system had their designers were familiar with file organization and data structures.
Hierarchical structure specify that an entity can have no more than a one owning entity the owning entity is called the parent the owned entity the child. A parent with no owner is called root. there is only one root in Hierarchical structure.
A parent can have many child, Where as a child can have only one parent.

Networking Database management system

The network model the data structure consisting of nodes and branches. In this structure allows a node to have more than one parent The nodes of the network represent records in various types relationship between records are represented as links which become pointer in the implementation.

Relational Database management system

The relationship model was proposed by E. F. Codd in 1970. It is now widely use both mainframe and microcomputer based DBMS, because of it simplicity from the user point of view and its power.

In relational models both entities and relationship are represented by relations, which are physically represented as tables or two dimensional arrays, and attributes as column of these tables. for example if we wish to store information about students and classes, we need a table for the student and the class. A student is related to the class by being enrolled in that class. These tables are linked to each other.

What is feasibility study

2014-10-12T03:52:00.001-07:00

What is feasibility study? Explain Technical, Economic, Legal, Operational, and Schedule feasibility in detail.

Feasibility study

Feasibility studies aim to objectively and rationally uncover the strengths and weaknesses of an existing business or proposed venture, opportunities and threats present in the environment, the resources required to carry through, and ultimately the prospects for success.In its simplest terms, the two criteria to judge feasibility are cost required and value to be attained.

A well-designed feasibility study should provide a historical background of the business or project, a description of the product or service, accounting statements, details of the operations and management, marketing research and policies, financial data, legal requirements and tax obligations.Generally, feasibility studies precede technical development and project implementation.

A feasibility study evaluates the project's potential for success; therefore, perceived objectivity is an important factor in the credibility of the study for potential investors and lending institutions.It must therefore be conducted with an objective, unbiased approach to provide information upon which decisions can be based.

The acronym TELOS refers to the five areas of feasibility - Technical, Economic, Legal, Operational, and Scheduling.

Legal Feasibility

Determines whether the proposed system conflicts with legal requirements, e.g. a data processing system must comply with the local Data Protection Acts.

Operational Feasibility

Operational feasibility is the ability to utilize, support and perform the necessary tasks of a system or program. It includes everyone who creates, operates or uses the system. To be operationally feasible, the system must fulfill a need required by the business. Programs that reduce costs without reducing the quality of a product are an example of operational feasibility. Studies are performed to make sure that programs can be initiated in the current production facility, without the need for more equipment or staff. If there is a need for more room, machinery or personnel, the system needs to make an improvement in the way the product is perceived by consumers. This allows the added expense to manufacture the product because of the anticipated increase in sales and revenue. Economic feasibility is one portion of operational feasibility. Everyone involved in the manufacturing and use of the system, product or program needs to understand it and be able to use it in the manner it was designed to be used. Feasibility studies are done not only in the private business sector, but by all governmental organizations. If the changes made to a product or program are not understood by the end users, it is not considered feasible.

Economic Feasibility

The purpose of the economic feasibility assessment is to determine the positive economic benefits to the organization that the proposed system will provide. It includes quantification and identification of all the benefits expected. This assessment typically involves a cost/ benefits analysis.

Technical Feasibility

The technical feasibility assessment is focused on gaining an understanding of the present technical resources of the organization and their applicability to the expected needs of the proposed system. It is an evaluation of the hardware and software and how it meets the need of the proposed system.

Schedule Feasibility

A project will fail if it takes too long to be completed before it is useful. Typically this means estimating how long the system will take to develop, and if it can be completed in a given time period using some methods like payback period. Schedule feasibility is a measure of how reasonable the project timetable is. Given our technical expertise, are the project deadlines reasonable? Some projects are initiated with specific deadlines. It is necessary to determine whether the deadlines are mandatory or desirable.