Technical Seminars

How to face a seminar?

2010-12-09T23:22:00.000-08:00

1). Memorizing - this is absolutely the worst way to keep track of material. People are preoccupied with trying to remember the words to say and not the ideas behind the words (or with the audience). As a result, normal voice inflection disappears. With memorizing, mental blocks become inevitable. With memorizing it is not a matter of "will" you forget; it's a matter of WHEN!

2). Reading from complete text - Listening to someone read a speech or presentation is hated by most people. People say, "If that's all they were going to do is read their speech, I could have read it myself." I'm sure many of us have experienced this at least once while attending a conference or two. Below are some reasons why I believe people read poorly:

3). Using Notes - This is the most common way for remembering material. Using notes is better than reading since the speaker can have normal voice inflection and make more effective eye contact. If your notes are on the lectern, you probably won't move very far from them. If notes are in your hand, you probably won't gesture very much.

4).Using Visual Aids As Notes - Simple visual aids can effectively serve as headings and subheadings. Speak to the heading. Say what you want to say and move on. If you forget something, that's okay; the audience will never know unless you tell them.
Practice creating just a few meaningful headings to use and practice using only these headings as your "cues". This will take practice, but practicing using only these few words will force you to better internalize your speech.

How to take good seminars?

2010-12-09T23:20:00.000-08:00

Outline of a typical presentationThe first slide has the title, the date of the paper and/or the talk, and your affiliation. If you have a co-author, this is the time to make that clear.
Try to provide a perspective (a puzzle, an empirical regularity, an historical example, a casual observation, a curious gap in the literature, etc.) that you can use as a "hook" to get your audience's attention.

Give an outline of the presentation.It's not necessary to read from the slide each of the steps of your talk (e.g., literature review, model, data, results, conclusion)--most of those present in the audience can read very well without your help. However, if you want to emphasize a particular part of your talk (e.g.. "I really want to get to the results so I'll skip quickly over the model during my talk. For those interested, the details are contained in my paper anyhow"), point this out right away.

Don't spend too much time on the literature review.The point of the review is to put your paper in perspective. Avoid getting into a long argument about whether you've cited the right group of papers or whether you have misrepresented a literature. You want to talk about your own work, not someone else's.

Present your main contributions right away. It's extremely important that you emphasize your contribution and distinguish what you've done that adds to the literature. You may want to repeat your list of contributions at the end of the talk, but don't try to keep the audience in suspense! Let them know your contribution immediately. This helps the audience focus on how to assess your paper and means that even those in the audience who leave early will have a good idea of what you want them to take away from your talk.

If you have a model in your paper that is involved and difficult to follow, try to present a stripped down version in the presentation that you can use to develop the intuition for the main findings. Then you can say that in the paper you show that the intuition extends to a richer setting.

If you put up a slide with an equation, make sure that you read through it so that the audience can follow the notation that you are using. If it's not standard (e.g., "F is a production function with inputs of capital and labour") try to give an economic interpretation of the equation.

If you put up a graph, make sure that it's clear what's on the two axes and that you describe what the graph demonstrates.

If you put up a table, make sure that you take one entry and explain clearly what it means in detail and then briefly indicate how to read the remaining entries.

You should have some planned 'slack' in your talk. That is material that you don't plan to cover but that you can include if for some reason you receive fewer or briefer questions than usual. Also, there may be parts of the talk where you anticipate that some audiences will want additional clarification and/or detail. Have it ready, but don't plan to use it unless it comes up in the talk.

Always keep your eye on the time remaining. If you start to fall behind in your planned pace you should try to adjust your talk by eliminating the least important remaining parts of your talk. Always aim to finish a few minutes early.

End with your conclusion slide. If you have started or plan to begin related research, mention it. Then prepare to kick back and think beyond your paper if that's what the audience wants.

How to take seminars effectively?

2010-12-09T23:19:00.000-08:00

Scientific Method

1) Please communicate clearly with your audience in this area - your presentation should demonstrate that you have evaluated the scientific merits or faults (as discussed in this course) of the research you are presenting, at least for Round 1 (where you present on a scientific paper)

2) For Round 2, please present the results of your project (either the 3 or 9 credit honors project or guided readings) in a way that makes it clear you have developed one or more hypotheses, deduced predictions from it/them, and tested it/them. If you are doing guided readings, you can present your work by beginning with the question or hypothesis that motivated the readings you did. Then, describe the scientific results you found in those readings and whether the results supported your initial hypothesis.

Organization

1) Be straightforward and logical, think of it as telling a story - you want a less expert audience to be able to follow along

2) Be certain to start with a brief introductory summary of what you will cover (outline!!!)

3) Provide sufficient background so that the audience can appreciate the significance of the paper (who cares???)

4) Use visual aids as appropriate, flow-charts can be very helpful when explaining methods and experimental designs

5) At the close of your seminar be certain to summarize the main conclusions and provide the audience with the most significant point(s) from the seminar* (don't leave the audience wondering why they sat through the seminar)

Clarity

1) Speak clearly and 'speak up' - project your voice without shouting at your audience

2) State the objectives, hypotheses and rationale of study right at the start of the talk

3) Be certain to relate the seminar to the larger context (Can we predict something better because this study was conducted? Do have better knowledge of a basic pattern in nature?)

4) Your seminar should be understandable to a general audience (remember: you have read paper or done the research - the audience won't have the same degree of preparation as you)

5) Be certain that you understand the work yourself and do not use a word that you could not explain! (avoid "bafflegab", especially if you don't get it yourself).

10 tips to take a seminar

2010-12-09T23:01:00.000-08:00

A speech needs time to grow. Prepare for weeks, sleep on it, dream about it and let your ideas sink into your subconscious. Ask yourself questions, write down your thoughts, and keep adding new ideas. As you prepare every speech ask yourself the following questions.

In one concise sentence, what is the purpose of this speech?
1) Who is the audience? What is their main interest in this topic?
2) What do I really know and believe about this topic as it relates to this audience?
3) What additional research can I do?
4) What are the main points of this presentation?
5) What supporting information and stories can I use to support each of my main points?
6) What visual aids, if any, do I need?
7) Do I have an effective opening grabber?
8) In my final summary, how will I plan to tell them "What's In It For Me?"
9) Have I polished and prepared the language and words I will use?

10) Have I taken care of the little details that will help me speak more confidently?

Aeronautical Communications

2010-12-08T04:08:00.000-08:00

In the future, airliners will provide a variety of entertainment and communications equipment to the passenger. Since people are becoming more and more used to their own communications equipment, such as mobile phones and laptops with Internet connection, either through a network interface card or dial-in access through modems, business travellers will soon be demanding wireless access to communication services. Specifically it focus on wireless services such as UMTS and W-LAN in aircraft cabins that connect the passenger via satellite to terrestrial infrastructure. Current trends are towards high data rate communication services, in particular internet applications. In an aeronautical scenario global coverage is essential for providing continuous service. Therefore satellite communication became indispensable, and together with ever increasing data rate requirements of applications, aeronautical satellite communication meets an expensive market. Certain features of UMTS and W-LAN that helps to provide these services are also explained.

INTRODUCTION

The demand for making air traveling more ‘pleasant, secure and productive for passengers is one of the winning factors for airlines and aircraft industry. Current trends are towards high data rate communication services, in particular Internet applications. In an aeronautical scenario global coverage is essential for providing continuous service. Therefore satellite communication becomes indispensable, and together with the ever increasing data rate requirements of applications, aeronautical satellite communication meets an expansive market.

Wireless Cabin (IST -2001-37466) is looking into those radio access technologies to be transported via satellite to terrestrial backbones . The project will provide UMTS services, W-LAN IEEE 802.11 b and Blue tooth to the cabin passengers. With the advent of new services a detailed investigation of the expected traffic is necessary in order to plan the needed capacities to fulfill the QoS demands. This paper will thus describe a methodology for the planning of such system.

Smart Memories

2010-12-08T04:03:00.001-08:00

Trends in VLSI technology scaling demand that future computing devices be narrowly focused to achieve high performance and high efficiency, yet also target the high volumes and low costs of widely applicable general-purpose designs. To address these conflicting requirements, here propose a modular reconfigurable architecture called Smart Memories, targeted at computing needs in the 0.1mm technology generation. A Smart Memories chip is made up of many processing tiles, each containing local memory, local interconnect, and a processor core. For efficient computation under a wide class of possible applications, the memories, the wires, and the computational model can all be altered to match the applications. To show the applicability of this design, two very different machines at opposite ends of the architectural spectrum, the Imagine stream processor and the Hydra speculative multiprocessor, are mapped onto the Smart Memories computing substrate. Simulations of the mappings show that the Smart Memories architecture can successfully map these architectures with only modest performance degradation.

INTRODUCTION

The continued scaling of integrated circuit fabrication technology will dramatically affect the architecture of future computing systems. Scaling will make computation cheaper, smaller, and lower power, thus enabling more sophisticated computation in a growing number of embedded applications. This spread of low-cost, low power computing can easily be seen in today’s wired (e.g. gigabit Ethernet or DSL) and wireless communication devices, gaming consoles, and handheld PDAs. These new applications have different characteristics from today’s standard workloads, often containing highly data-parallel streaming behavior. While the applications will demand ever-growing compute performance, power (ops/W) and computational efficiency (ops/$) are also paramount; therefore, designers have created narrowly focused custom silicon solutions to meet these needs.

However, the scaling of process technologies makes the construction of custom solutions increasingly difficult due to the increasing complexity of the desired devices. While designer productivity has improved over time, and technologies like system-on-a-chip help to manage complexity, each generation of complex machines is more expensive to design than the previous one. High non-recurring fabrication costs (e.g. mask generation) and long chip manufacturing delays mean that designs must be all the more carefully validated, further increasing the design costs. Thus, these large complex chips are only cost-effective if they can be sold in large volumes. This need for a large market runs counter to the drive for efficient, narrowly- focused, custom hardware solutions.

To fill the need for widely applicable computing designs, a number of more general-purpose processors are targeted at a class of problems, rather than at specific applications. Tri-media, Equator, Mpact, IRAM, and many other projects are all attempts to create general purpose computing engine for multi-media applications. However, these attempts to create more universal computing elements have some limitations. First, these machines have been optimized for applications where the parallelism can be expressed at the instruction level using either VLIW or vector engines. However, they would not be very efficient for applications that lacked parallelism at this level, but had, for example, thread level parallelism. Second, their globally shared resource models (shared multi-ported registers and memory) will be increasingly difficult to implement in future technologies in which on-chip communication costs are appreciable. Finally, since these machines are generally compromise solutions between true signal processing engines and general-purpose processors, their efficiency at doing either task suffers.

Modelling of Delay Lines on Pcbs

2010-12-08T04:01:00.001-08:00

Designers of printed circuit boards often face the problem illustrated by the example in Figure 1.It is desired to transmit signals 1, 2 and 3 from one chip to the other with precisely the same transmission delay. However, with the routing pattern in Figure 1a, signal 3 has a longer path and will arrive later. The conventional solution, shown in Figure 1b, artificially extends the paths of signals 1 and 2 to match the lengths of all wires.

An example where meander lines might be used is as a bus between a processor and memory. Another example is a clock distribution tree between a clock synthesizer and target clocked circuits.

Traces such as those for signals 1 and 2 are called serpentine lines or meander lines. In the past, meander lines have been used with the assumption that the extra wire length is electrically identical to a straight section, and no parasitics were introduced. As trace dimensions become smaller and signal frequencies increase, that assumption may no longer be valid.

In this report, we present measurements of the time delay through, and characteristic impedance of meander lines as compared to an equivalent length of straight line.

It is seen that the delay through a meander line is shorter than the delay through an equivalent length of straight trace. This is because coupling between the segments of the meander lines shortens the electrical path.

The remainder of this report is organized as follows. Section 2 gives the physical background of transmission lines and meander lines, and defines terms used in the rest of the report. Section 3 discusses our measurement methods and reports experimental results. In Section 4, we discuss the results, and Section 5 gives a model for the observed effects. Finally, Section 6 gives conclusions.

Smart Dust

2010-12-08T03:57:00.001-08:00

The ‘Smart Dust’ project is aiming to build an autonomous sensing, computing, and communication system packed into a cubic-millimeter mote, to form the basis of integrated, massively distributed sensor networks. So, this device will be around the size of a grain of sand and will contain sensors, computational ability, bidirectional wireless communications, and power supply, while being inexpensive enough to deploy by the hundreds. Smart Dust requires evolutionary and revolutionary advances in integration, miniaturization and energy management.

If the project is successful, clouds of smart dust could one day be used in an astonishing array of application, from following enemy troop movements and hunting send missiles to detecting toxic chemicals in the environment and monitoring weather patters around the globe.

INTRODUCTION

The current ultramodern technologies are focusing on automation and miniaturization. The decreasing computing device size, increased connectivity and enhanced interaction with the physical world have characterized computing’s history. Recently, the popularity of small computing devices, such as hand held computers and cell phones; rapidly flourishing internet group and the diminishing size and cost of sensors and especially transistors have accelerated these strengths. The emergence of small computing elements, with sporadic connectivity and increased interaction with the environment, provides enriched opportunities to reshape interactions between people and computers and spur ubiquitous computing researches.

Smart dust is tiny electronic devices designed to capture mountains of information about their surroundings while literally floating on air. Nowadays, sensors, computers and communicators are shrinking down to ridiculously small sizes. If all of these are packed into a single tiny device, it can open up new dimensions in the field of communications.

The idea behind ‘smart dust’ is to pack sophisticated sensors, tiny computers and wireless communicators in to a cubic-millimeter mote to form the basis of integrated, massively distributed sensor networks. They will be light enough to remain suspended in air for hours. As the motes drift on wind, they can monitor the environment for light, sound, temperature, chemical composition and a wide range of other information, and beam that data back to the base station, miles away.

Real-time systems

2010-12-08T03:57:00.000-08:00

Real-time systems play a considerable role in our society, and they cover a spectrum from the very simple to the very complex. Examples of current real-time systems include the control of domestic appliances like washing machines and televisions, the control of automobile engines, telecommunication switching systems, military command and control systems, industrial process control, flight control systems, and space shuttle and aircraft avionics.

All of these involve gathering data from the environment, processing of gathered data, and providing timely response. A concept of time is the distinguishing issue between real-time and non-real-time systems. When a usual design goal for non-real-time systems is to maximize system’s throughput, the goal for real-time system design is to guarantee, that all tasks are processed within a given time. The taxonomy of time introduces special aspects for real-time system research.

Real-time operating systems are an integral part of real-time systems. Future systems will be much larger, more widely distributed, and will be expected to perform a constantly changing set of duties in dynamic environments. This also sets more requirements for future real-time operating systems.

This seminar has the humble aim to convey the main ideas on Real Time System and Real Time Operating System design and implementation.

INTRODUCTION

Timeliness is the single most important aspect of a real -time system. These systems respond to a series of external inputs, which arrive in an unpredictable fashion. The real-time systems process these inputs, take appropriate decis ions and also generate output necessary to control the peripherals connected to them. As defined by Donald Gillies “A real-time system is one in which the correctness of the computations not only depends upon the logical correctness of the computation but also upon the time in which the result is produced. If the timing constraints are not met, system failure is said to have occurred.”

It is essential that the timing constraints of the system are guaranteed to be met. Guaranteeing timing behaviour requires that the system be predictable.

The design of a real -time system must specify the timing requirements of the system and ensure that the system performance is both correct and timely. There are three types of time constraints:

Ø Hard: A late response is incor rect and implies a system failure. An example of such a system is of medical equipment monitoring vital functions of a human body, where a late response would be considered as a failure.

Ø Soft: Timeliness requirements are defined by using an average respons e time. If a single computation is late, it is not usually significant, although repeated late computation can result in system failures. An example of such a system includes airlines reservation systems.

Ø Firm: This is a combination of both hard and soft t imeliness requirements. The computation has a shorter soft requirement and a longer hard requirement. For example, a patient ventilator must mechanically ventilate the patient a certain amount in a given time period. A few seconds’ delay in the initiation of breath is allowed, but not more than that.

One need to distinguish between on -line systems such as an airline reservation system, which operates in real-time but with much less severe timeliness constraints than, say, a missile control system or a telephone switch. An interactive system with better response time is not a real-time system. These types of systems are often referred to as soft real time systems. In a soft real -time system (such as the airline reservation system) late data is still good dat a. However, for hard real -time systems, late data is bad data. In this paper we concentrate on the hard and firm real-time systems only.

Most real -time systems interface with and control hardware directly. The software for such systems is mostly custom -developed. Real -time Applications can be either embedded applications or non -embedded (desktop) applications. Real -time systems often do not have standard peripherals associated with a desktop computer, namely the keyboard, mouse or conventional display monitors. In most instances, real-time systems have a customized version of these devices.

Quantum Dot Lasers

2010-12-08T03:56:00.001-08:00

The infrastructure of the Information Age has to date relied upon advances in microelectronics to produce integrated circuits that continually become smaller, better, and less expensive. The emergence of photonics, where light rather than electricity is manipulated, is posed to further advance the Information Age. Central to the photonic revolution is the development of miniature light sources such as the Quantum dots(QDs). Today, Quantum Dots manufacturing has been established to serve new datacom and telecom markets.

Recent progress in microcavity physics, new materials, and fabrication technologies has enabled a new generation of high performance QDs. This presentation will review commercial QDs and their applications as well as discuss recent research, including new device structures such as composite resonators and photonic crystals

Semiconductor lasers are key components in a host of widely used technological products, including compact disk players and laser printers, and they will play critical roles in optical communication schemes. The basis of laser operation depends on the creation of non-equilibrium populations of electrons and holes, and coupling of electrons and holes to an optical field, which will stimulate radiative emission. . Other benefits of quantum dot active layers include further reduction in threshold currents and an increase in differential gain-that is, more efficient laser operation.

Since the 1994 demonstration of a quantum dot (QD) semiconductor laser, the research progress in developing lasers based on QDs has been impressive. Because of their fundamentally different physics that stem from zero-dimensional electronic states, QD lasers now surpass the established planar quantum well laser technology in several respects. These include their minimum threshold current density, the threshold dependence on temperature, and range of wavelengths obtainable in given strained layer material systems. Self-organized QDs are formed from strained-layer epitaxy. Upon reaching such conditions, the growth front can spontaneously reorganize to form 3-dimensional islands. The greater strain relief provided by the 3-dimensionally structured crystal surface prevents the formation of dislocations. When covered with additional epitaxy, the coherently strained islands form the QDs that trap and isolate individual electron-hole pairs to create efficient light emitters.

Laser Communication

2010-12-08T03:56:00.000-08:00

Laser communications offer a viable alternative to RF communications for inter satellite links and other applications where high-performance links are a necessity. High data rate, small antenna size, narrow beam divergence, and a narrow field of view are characteristics of laser communications that offer a number of potential advantages for system design.

Lasers have been considered for space communications since their realization in 1960. Specific advancements were needed in component performance and system engineering particularly for space qualified hardware. Advances in system architecture, data formatting and component technology over the past three decades have made laser communications in space not only viable but also an attractive approach into inter satellite link applications.

Information transfer is driving the requirements to higher data rates, laser cross -link technology explosions, global development activity, increased hardware, and design maturity. Most important in space laser communications has been the development of a reliable, high power, single mode laser diode as a directly modulable laser source. This technology advance offers the space laser communication system designer the flexibility to design very lightweight, high bandwidth, low-cost communication payloads for satellites whose launch costs are a very strong function of launch weigh. This feature substantially reduces blockage of fields of view of most desirable areas on satellites. The smaller antennas with diameter typically less than 30 centimeters create less momentum disturbance to any sensitive satellite sensors. Fewer on board consumables are required over the long lifetime because there are fewer disturbances to the satellite compared with heavier and larger RF systems. The narrow beam divergence affords interference free and secure operation.

BLAST

2010-12-08T03:55:00.001-08:00

BLAST is a wireless communications technique which uses multi-element antennas at both transmitter and receiver to permit transmission rates far in excess of those possible using conventional approaches.

In wireless systems, radio waves do not propagate simply from transmit antenna to receive antenna, but bounce and scatter randomly off objects in the environment. This scattering known as multipath, as it results in multiple copies (“images”) of the transmitted sign arriving at the receiver via different scattered paths. In conventional wireless system multipath represents a significant impediment to accurate transmission, because the image arrive at the receiver at slightly different times and can thus interfere destructively, canceling each other out. For this reason, multipath is traditionally viewed as a serious impairment. Using the BLAST approach however, it is possible toexploit multipath, that is, to use the scattering characteristics of the propagation environment to enhance, rather than degrade transmission accuracy by treating the multiplicity of scattering paths as separate parallel sub channels.

INTRODUCTION

The explosive growth of both the wireless industry and the Internet is creating a huge market opportunity for wireless data access. Limited internet access, at very low speeds, is already available as an enhancement to some existing cellular systems. However those systems were designed with purpose of providing voice services and at most short messaging, but not fast data transfer. Traditional wireless technologies are not very well suited to meet the demanding requirements of providing very high data rates with the ubiquity, mobility and portability characteristics of cellular systems. Increased use of antenna arrays appears to be the only means of enabling the type of data rates and capacities needed for wireless internet and multimedia services. While the deployment of base station arrays is becoming universal it is really the simultaneous deployment of base station and terminal arrays that can unleash unprecedented levels of performance by opening up multiple spatial signaling dimensions .Theoretically, user data rates as high as 2 Mb/sec will be supported in certain environments, although recent studies have shown that approaching those might only be feasible under extremely favorable conditions-in the vicinity of the base station and with no other users competing for band width. Some fundamental barriers related to the nature of radio channel as well as to the limited band width availability at the frequencies of interest stand in the way of high data rates and low cost associated with wide access.

ATM

2010-12-08T03:54:00.001-08:00

Nowadays, most us are surrounded by powerful computer systems with graphics oriented input and output.

These computers include the entire spectrum of PCs, through professional workstations upto super-computers. As the performance of computers has increased, so too has the demand for communication between all systems for exchanging data, or between central servers and the associated host computer system.

The replacement of copper with fiber and the advancement sin digital communication and encoding are at the heart of several developments that will change the communication infrastructure. The former development has provided us with huge amount of transmission bandwidth. While the latter has made the transmission of all information including voice and video through a packet switched network possible.

With continuously work sharing over large distances, including international communication, the systems must be interconnected via wide area networks with increasing demands for higher bit rates.

For the first time, a single communications technology meets LAN and WAN requirements and handles a wide variety of current and emerging applications. ATM is the first technology to provide a common format for bursts of high speed data and the ebb and flow of the typical voice phone call. Seamless ATM networks provide desktop-to-desktop multimedia networking over single technology, high bandwidth, low latency network, removing the boundary between LAN WAN.

ATM is simply a Data Link Layer protocol. It is asynchronous in the sense that the recurrence of the cells containing information from an individual user is not necessarily periodic. It is the technology of choice for evolving B-ISDN (Board Integrated Services Digital Network), for next generation LANs and WANs. ATM supports transmission speeds of 155Mbits / sec. In the future. Photonic approaches have made the advent of ATM switches feasible, and an evolution towards an all packetized, unified, broadband telecommunications and data communication world based on ATM is taking place.

BLAST

2010-12-08T03:52:00.001-08:00

INTRODUCTION

Blue Eyes

2010-12-08T03:49:00.001-08:00

Imagine yourself in a world where humans interact with computers. You are sitting in front of your personal computer that can listen, talk, or even scream aloud. It has the ability to gather information about you and interact with you through special techniques like facial recognition, speech recognition, etc. It can even understand your emotions at the touch of the mouse. It verifies your identity, feels your presents, and starts interacting with you .You ask the computer to dial to your friend at his office. It realizes the urgency of the situation through the mouse, dials your friend at his office, and establishes a connection.

Human cognition depends primarily on the ability to perceive, interpret, and integrate audio-visuals and sensoring information. Adding extraordinary perceptual abilities to computers would enable computers to work together with human beings as intimate partners. Researchers are attempting to add more capabilities to computers that will allow them to interact like humans, recognize human presents, talk, listen, or even guess their feelings.

The BLUE EYES technology aims at creating computational machines that have perceptual and sensory ability like those of human beings. It uses non-obtrusige sensing method, employing most modern video cameras and microphones to identifies the users actions through the use of imparted sensory abilities . The machine can understand what a user wants, where he is looking at, and even realize his physical or emotional states.

EMOTION MOUSE

One goal of human computer interaction (HCI) is to make an adaptive, smart computer system. This type of project could possibly include gesture recognition, facial recognition, eye tracking, speech recognition, etc. Another non-invasive way to obtain information about a person is through touch. People use their computers to obtain, store and manipulate data using their computer. In order to start creating smart computers, the computer must start gaining information about the user. Our proposed method for gaining user information through touch is via a computer input device, the mouse. From the physiological data obtained from the user, an emotional state may be determined which would then be related to the task the user is currently doing on the computer. Over a period of time, a user model will be built in order to gain a sense of the user’s personality. The scope of the project is to have the computer adapt to the user in order to create a better working environment where the user is more productive. The first steps towards realizing this goal are described here.

BiCMOS Technology

2010-12-08T03:41:00.001-08:00

The need for high-performance, low-power, and low-cost systems for network transport and wireless communications is driving silicon technology toward higher speed, higher integration, and more functionality. Further more, this integration of RF and analog mixed-signal circuits into high-performance digital signal-processing (DSP) systems must be done with minimum cost overhead to be commercially viable. While some analog and RF designs have been attempted in mainstream digital-only complimentary metal-oxide semiconductor (CMOS) technologies, almost all designs that require stringent RF performance use bipolar or semiconductor technology. Silicon integrated circuit (IC) products that, at present, require modern bipolar or BiCMOS silicon technology in wired application space include the essential optical network (SONET) and synchronous digital hierarchy (SDH) operating at 10 Gb/s and higher.

The viability of a mixed digital/analog. RF chip depends on the cost of making the silicon with the required elements; in practice, it must approximate the cost of the CMOS wafer, Cycle times for processing the wafer should not significantly exceed cycle times for a digital CMOS wafer. Yields of the SOC chip must be similar to those of a multi-chip implementation. Much of this article will examine process techniques that achieve the objectives of low cost, rapid cycle time, and solid yield.

INTRODUCTION

The history of semiconductor devices starts in 1930’s when Lienfed and Heil first proposed the mosfet. However it took 30 years before this idea was applied to functioning devices to be used in practical applications, and up to the late 1980 this trend took a turn when MOS technology caught up and there was a cross over between bipolar and MOS share.CMOS was finding more wide spread use due to its low power dissipation, high packing density and simple design, such that by 1990 CMOS covered more than 90% of total MOS scale.

In 1983 bipolar compatible process based on CMOS technology was developed and BiCMOS technology with both the MOS and bipolar device fabricated on the same chip was developed and studied. The objective of the BiCMOS is to combine bipolar and CMOS so as to exploit the advantages of both at the circuit and system levels. Since 1985, the state-of-the-art bipolar CMOS structures have been converging. Today BiCMOS has become one of the dominant technologies used for high speed, low power and highly functional VLSI circuits especially when the BiCMOS process has been enhanced and integrated in to the CMOS process without any additional steps. Because the process step required for both CMOS and bipolar are similar, these steps cane be shared for both of them.

CDMA

2010-12-08T03:38:00.001-08:00

Code-Division Multiple Access, a digital cellular technology that uses spread-spectrum techniques. Unlike competing systems, such as GSM, that use TDMA, CDMA does not assign a specific frequency to each user. Instead, every channel uses the full available spectrum. Individual conversations are encoded with a pseudo-random digital sequence.

As the term implies, CDMA is a form of multiplexing which allows numerous signals to occupy a single transmission channel, optimizing the use of available bandwidth. The technology is used in ultra-high-frequency (UHF) cellular telephone systems in the 800-M1-Iz and 1.9-GHz bands.

CDMA employs analog-to-digital conversion (ADC) in combination with spread spectrum technology. Audio input is first digitized into binary elements. The frequency of the transmitted signal is then made to vary according to a defined pattern (code), so it can be intercepted only by a receiver whose frequency response is programmed with the same code, so it follows exactly along with the transmitter frequency. There are trillions of possible frequency-sequencing codes; this enhances privacy and makes cloning difficult.

The CDMA channel is nominally 1.23 MHz wide. CDMA networks use a scheme called soft handoff, which minimizes signal breakup as a handset passes from one cell to another. The combination of digital and spread spectrum modes supports several times as many signals per unit bandwidth as analog modes. CDMA is compatible with other cellular technologies; this allows for nationwide Roaming…….

Boiler Instrumentation and Controls

2010-12-08T03:36:00.001-08:00

Instrumentation and controls in a boiler plant encompass an enormous range of equipment from simple in the small industrial plant to the complex in the large utility station. Boiler Instrumentation Control is the control over the industrial boilers. It consists of several control loops to control various systems related to a boiler. The main control of boilers include combination control and feed water control. To do the various operations in control different hardware methods are used.

Virtually any boiler-old or new, industrial or utility can benefit from or several control system modifications available today either by introducing advanced control schemes adding to existing control schemes

INTRODUCTION

Instrumentation and controls in a boiler plant encompass an enormous range of equipment from simple industrial plant to the complex in the large utility station.

The boiler control system is the means by which the balance of energy & mass into and out of the boiler are achieved. Inputs are fuel, combustion air, atomizing air or steam &feed water. Of these, fuel is the major energy input. Combustion air is the major mass input, outputs are steam, flue gas, blowdown, radiation & soot blowing.

CONTROL LOOPS

Boiler control systems contain several variable with interaction occurring among the control loops for fuel, combustion air, & feedwater . The overall system generally can be treated as a series of basic control loops connected together. for safety purposes, fuel addition should be limited by the amount of combustion air and it may need minimum limiting for flame stability.

Combustion controls

Amounts of fuel and air must be carefully regulated to keep excess air within close tolerances-especially over the loads. This is critical to efficient boiler operation no matter what the unit size, type of fuel fired or control system used.

Feedwater control

Industrial boilers are subject to wide load variations and require quick responding control to maintain constant drum level. Multiple element feed water control can help faster and more accurate control response…

Cable Modems

2010-12-08T03:34:00.001-08:00

A cable modem is a digital device, which connects the computer system to the Internet, via a coaxial cable, usually the same as used in a cable television network. It converts digital information into modulated RF signals(upstream) and RF signals back to digital information (downstream) across cable TV networks. Cable modem allows high-speed access to the Internet via a cable TV network. A cable modem will typically have two connections, one to the cable wall outlet and one to a computer. Most cable modems are external devices that connect to the PC through a standard 10Base-T Ethernet card and twisted-pair wiring. Cable modem speeds vary widely, depending on the cable modem system, cable network architecture, and traffic load. In the downstream direction (from the network to the computer), network speeds can be anywhere up to 27 Mbps, an aggregate amount of bandwidth that is shared by users. In the upstream direction (from computer to network), speeds can be up to 10 Mbps. However, most modem producers have selected a more optimum speed between 500 Kbps and 2.5 Mbps. An asymmetric scheme is used in most cable modems.

The term ‘Cable Modem’ is quite new and refers to a modem that operates over the ordinary cable TV network cables. Basically you just connect the Cable Modem to the TV outlet for your cable TV, and the cable TV operator connects a Cable Modem Termination System (CMTS) in his end (the Head-End).

Actually the term “Cable Modem” is a bit misleading, as a Cable Modem works more like a Local Area Network (LAN) interface than as a modem.

Cable modems allow consumers access to the Internet at higher speeds and at a fraction of the time it takes traditional telephone modems.

This is true for two reasons:

1. Broadband networks make the connection up to a hundred times faster

2. The service is “always on,” meaning customers get the information they want, when they want it.

Unlike telephone modems, cable modems allow consumers to keep their telephone lines open for voice conversations.

Distributed Wireless Communication

2010-12-08T03:32:00.001-08:00

With the rapid progress in telecommunications, more and more services are provided on the basis of broadband communications, such as video services and high-speed Internet. With worldwide fundamental construction of a backbone network based on optical fiber providing almost unlimited communications capability, the limited throughput of the subscriber loop becomes one of the most stringent bottlenecks.Compared to the capacity of the backbone network, which is measured by tens of gigabits per second, the throughput of the subscriber loop is much lower, only up to hundreds of megabits per second for wired systems (including fixed wireless access). However, for mobile access the throughput is even lower, and depends on the mobility of the terminal. For example, the peak data rate is only 2 Mb/s for 3G systems. Since there will be more and more need for mobile services, the poor throughput of mobile access not only limits user applications based on interconnection, but also wastes the capability of the backbone network. This case is quite similar to the traffic conditions shown in Fig. a, which is an image of an ultra-wide expressway with a few narrow entrances. Since the little paths are rough, narrow, and crowded, the problems in Fig. a are:

 Terminals are far away from the expressway, which will consume much power.

 Too many cars converge into the same narrow paths.

 Little paths converge several times before going into the expressway.

 The expressway is used insufficiently, since few cars are running on it.

In telecommunications, the optical fiber network (expressway) is relatively much cheaper than the wireless spectrum (little paths), while the capability of the former is much greater than that of the later. As shown in Fig. b, besides the backbone expressway, there are some dedicated sub expressways used to provide direct entrance for distributed subscribers. The above example implies that the high-capacity wired network, being so cheap, can help us solve the problem of wireless access(too many users crowded in a very narrow bandwidth). The key issue is to provide each mobile user a direct or one-hop connection to an optical network.This structure also follows the trend in network evolution: the hierarchical or tree-like structure of traditional networks will be gradually flattened to simple single-layer ones.

Free Space Optics

2010-12-08T03:28:00.001-08:00

Free space optics or FSO, free space photonics or optical wireless, refers to the transmission of modulated visible or infrared beams through the atmosphere to obtain optical communication. FSO systems can function over distances of several kilometers. FSO is a line-of-sight technology, which enables optical transmission up to 2.5 Gbps of data, voice and video communications, allowing optical connectivity without deploying fiber optic cable or securing spectrum licenses. Free space optics require light, which can be focused by using either light emitting diodes (LED) or LASERS(light amplification by stimulated emission of radiation). The use of lasers is a simple concept similar to optical transmissions using fiber-optic cables, the only difference being the medium.

As long as there is a clear line of sight between the source and the destination and enough transmitter power, communication is possible virtually at the speed of light. Because light travels through air faster than it does through glass, so it is fair to classify FSO as optical communications at the speed of light. FSO works on the same basic principle as infrared television remote controls, wireless keyboards or wireless palm devices.

Electronic Nose

2010-12-08T03:26:00.001-08:00

The harnessing of electronics to measure odor is greatly to be desired. Human panels backed up by gas chromatography and mass spectrometry are helpful in quantifying smells, but they time are consuming, expensive and seldom performed in real time in the field. So it is important that these traditional methods give way to a speedier procedure using and electronic nose composed of gas sensors. Electronic nose or E-noses are the systems that detect and identify odours and vapours, typically linking chemical sensing devices with signal processing, pattern recognition and artificial intelligence techniques which enable uses to readily extract relevant and reliable information.

INTRODUCTION

The electronics field is developing at a fast rate. Each day the industry is coming with new technology and products. The electronic components play a major role in all fields of life. The scientists had started to mimic the biological world. The development of artificial neural network (ANN), in which the nervous system is electronically implemented is one among them.

The scientists realized the importance of the detection and identification of odor in many fields. In human body it is achieved with the help of one of the sense organ, the nose. So scientists realized the need of imitating the human nose. The concept of the electronic nose appeared for the first time in a nature paper by Persuade and Dodd (1982). The authors suggested and demonstrated with a few examples that gas sensor array responses could be analyzed with artificial neural networks thereby increasing sensitivity and precision in analysis significantly. This first publication was followed by several methodological papers evaluating different sensor types and combinations.

The scientists saw the last advances in the electronic means of seeing and hearing. Witnessing this fast advances they scent a marker for systems mimicking the human nose. The harnessing of electronics to measure odor is greatly desired. Human panels backed by gas chromatography (GC)/ mass spectroscopy (MS) are helpful in quantifying smells. The human panels are subject to fatigue and inconsistencies. While classical gas chromatography (GC)/ mass spectrograph (MS) technique separate quantify and identify individual volatile chemicals, they cannot tell us if the components have an odour. Also they are very slow. So it is important that faster methods must give way to speedier procedure using an electronic nose composed of gas sensory. The E-nose was developed not to replace traditional GC/MS and sensory techniques. The E-nose was sensitive and as discriminating as the human nose, and it also correlates extremely with GC/MS data. The electronic nose allows to transfer expert know ledged from highly trained sensory panels and very sophisticated R&D analytical techniques to the production floor for the control of quality. Although the human nose is very sensitive, it is highly subjective. The E – nose offers objectivity and reproducibility.

The electronic nose technology goes several steps ahead of the conventional gas sensors. The electronics nose system detects and sensing devices with pattern recognition sub system. The electronic nose won quickly considerable interest in food analysis for rapid and reliable quality classification in manufacturing testing. Later, the electronic noses have also been applied to classification of micro organisms and bio-reactor monitoring. Even though the electronic nose resembles its biological counter part nose too closely the label “electronic nose” or “E-nose” has been widely accepted around the world.

Electrophysiological Interactive Computer Systems

2010-12-08T03:24:00.003-08:00

New interactive computing applications are continually being developed in a bid to support people’s changing work and recreational activities. As research focuses on one particular class interactive systems, high level models of interaction are formulated and requirements emerge that reflect shared features or common functionality among those systems. The existence of models of interaction and shared functional requirements mean that support tools can be created which ease the subsequent development of these systems. The type of tool that interactive systems developers are most familiar with is a library of reusable code that can be used for prototyping and building interactive applications and their interfaces.

A new class of interactive system is identified, based on shared requirements for detection, processing and presentation of human physiological information. This is electro physiological interactive computers systems. It is envisaged that the work will serve as a jumping of point for others interested in exploring the potential of incorporating physiological information into the human machine relationship. A method of hands free of human computer interaction currently under investigation is based on the detection of consciously controllable human physiological information. This physiological information can be processed electrically and thereafter transformed into computer control signals and commands.

INTRODUCTION

EPICS is a new class of interactive system based on detection, processing and presentation of human physiological information .A user physically manipulates an electromechanical device to initiate a computer operation requires the periodic dedication one or both hands. Unfortunately many people work in environments where their hands are fully occupied with other physical tasks. Examples include surgeons, fitters, maintenance engineers, aircraft flight crew and drivers of heavy goods, passenger and private vehicles. In all of these situations, access to information would be better served by alternative, hands-free access control. A further limitation of existing mechanical models of interaction is that they exclude access to those individuals for whom normal physical control is either difficult or impossible. It is clear that supplemental methods of human-machine interaction to those currently available are needed.

EPICS are interactive systems in which the physiological information can be processed electrically and thereafter transformed into computer control signals and commands. Using specialised electronic sensing equipment it is possible to both detect and make available in digital format information pertaining to a wide range of human physiology. Physiological sensing equipment can be used in order to train individuals to gain conscious control over a range of physiological parameters including heart rate, muscle tension and brain activity. The process of making physiological information available to a subject who is being trained to control some aspect of his or her own physiology is known as bio feed back. After training, physiological signals can be applied to hands free human machine control. It can utilize electrical brain activity to directly control a cursor on a computer screen and to input alphanumeric character using a soft keyboard….

Ferroelectric Memory(FRAM)

2010-12-08T03:21:00.001-08:00

Ferroelectric memory is a new type of semiconductor memory, which exhibit short programming time, low power consumption and nonvolatile memory, making highly suitable for application like contact less smart card, digital cameras which demands many memory write operations.

A ferroelectric memory technology consists of a complementary metal-oxide-semiconductor (CMOS) technology with added layers on top for ferroelectric capacitors. A ferroelectric memory cell has at least one ferroelectric capacitor to store the binary data, and one transistor that provide access to the capacitor or amplify its content for a read operation. Once a cell is accessed for a read operation, its data are presented in the form of an analog signal to a sense amplifier, where they are compared against a reference voltage to determine their logic level.

Ferroelectric memories have borrowed many circuit techniques (such as folded-bitline architecture) from DRAM’s due to similarities of their cells and DRAM’s maturity. Some architectures are reviewed here.

INTRODUCTION

Before the 1950’s, ferromagnetic cores were the only type of random-access, nonvolatile memories available. A core memory is a regular array of tiny magnetic cores that can be magnetized in one of two opposite directions, making it possible to store binary data in the form of a magnetic field. The success of the core memory was due to a simple architecture that resulted in a relatively dense array of cells. This approach was emulated in the semiconductor memories of today (DRAM’s, EEPROM’s, and FRAM’s). Ferromagnetic cores, however, were too bulky and expensive compared to the smaller, low-power semiconductor memories. In place of ferromagnetic cores ferroelectric memories are a good substitute. The term “ferroelectric’ indicates the similarity, despite the lack of iron in the materials themselves.

Ferroelectric memory exhibit short programming time, low power consumption and nonvolatile memory, making highly suitable for application like contact less smart card, digital cameras which demanding many memory write operations. In other word FRAM has the feature of both RAM and ROM. A ferroelectric memory technology consists of a complementry metal-oxide-semiconductor (CMOS) technology with added layers on top for ferroelectric capacitors. A ferroelectric memory cell has at least one ferroelectric capacitor to store the binary data, and one or two transistors that provide access to the capacitor or amplify its content for a read operation.

A ferroelectric capacitor is different from a regular capacitor in that it substitutes the dielectric with a ferroelectric material (lead zirconate titanate (PZT) is a common material used)-when an electric field is applied and the charges displace from their original position spontaneous polarization occurs and displacement becomes evident in the crystal structure of the material. Importantly, the displacement does not disappear in the absence of the electric field. Moreover, the direction of polarization can be reversed or reoriented by applying an appropriate electric field.

A hysteresis loop for a ferroelectric capacitor displays the total charge on the capacitor as a function of the applied voltage. It behaves similarly to that of a magnetic core, but for the sharp transitions around its coercive points, which implies that even a moderate voltage can disturb the state of the capacitor. One remedy for this would be to modify a ferroelectric memory cell including a transistor in series with the ferroelectric capacitor. Called an access transistor, it wo control the access to the capacitor and eliminate the need for a square like hysteresis loop compensating for the softness of the hysteresis loop characteristics and blocking unwanted disturb signals from neighboring memory cells.

Once a cell is accessed for a read operation, its data are presented in the form of an anal signal to a sense amplifier, where they are compared against a reference voltage to determine the logic level.

Geographic Information System(GIS)

2010-12-08T03:19:00.001-08:00

Geographic Information System(GIS) is a computer system that records,stores and analyzes information about the features that make up the earth’s surface. A GIS can generate two or three dimensional images of an area,showing such natural features as hills and rivers with artificial features such as roads and power lines.Scientists use GIS images as models , making precise measurements, gathering data and testing ideas with the help of the computer.

Many GIS databases consist of sets of information called layers. Each layers represents a particular type of geographic data.A GIS database can include as many as 100 layers.

A GIS is designed to accept geographic data from a variety of sources ,including maps ,satellite photographs and printed text and statistics. GIS sensors can scan some of this data directly.The GIS converts all geographical data into a digital code,which it arranges in its database. Operators program the GIS to process the information and produce the images or information they need.

The applications of a GIS are vast and continue to grow.By using a GIS, scientists can research changes in the environment , engineers can design road systems ,electrical companies can manage their complex networks of power lines,governments can track the uses of land and fire and police departments can plan emergency routes.Many private businessess have begun to use a GIS to plan and improve their services.

The idea of using map layers is an old one. Layered information from traditional maps had been used for practical purposes for a long time. But computers made the application of this concept much more practical.

GIS was a welcome change from the era of hand cartography when maps had to be painstakingly created by hand ,even small changes required the creation of a new map . The earliest version of a GIS was known as computer cartography and involved simple line work to represent land features on the top of each other to determine patterns and causes of spatial phenomenon.

The capabilities of GIS are a far cry from the simple beginnings of computer cartography. at the simplest level ,GIS can be thought of as a high-tech equivalent of a map. However,not only can paper maps be produced far quicker and more efficiently,the storage of data in an easily accessible digital format enables complex analysis and modeling not previously possible. The reach of GIS expands into all disciplines and has been used for such widely ranged problems such as prioritizing sensitive species habitat to determining optimal real estate locations for new businesses.

The keyword to this technology is geography,this usually means that the data is spatial, in other words ,data that is in some way referenced to locations on the earth. Coupled with this is usually data known as attribute data. Attribute data generally defined as additional information, which can be tied to spatial data. An example of this would be schools. The location of the schools is the spatial data. Additional data such as the school’s name,level of education taught ,school capacity would make up the attribute data. It is the partnership of these two data that enables GIS to be such an effective problem solving tool.

GIS operates on many levels. On the most basic level , GIS is used as computer cartography , i.e. mapping. The real power in GIS is through using spatial and statistical methods to analyze attribute and geographic information. The end results of the analysis can br derivative information, interpolated information.