Electrical and Electronics Commons^™

Schottky-Barrier Solar Cells, Surface Patterning For Efficient Light Collection, Constantinos Manolis

Theses

Different geometrical surface configurations are considered here for a Au/n-Si semiconductor Schottky-barrier solar cell to improve their light collection efficiency.

Optical and electrical properties are theoretically analyzed for two given optical wavelengths of 0.9 and 0.5 micrometers respectively.

The configurations considered are: V-shaped, Star- shaped, M-shaped, asymmetric-V-shaped, and asymmetric-M-shaped. They all show a significant improvement in the short-circuit current over a flat cell model, while the open-circuit voltage remains practically unchanged.

Computer Controlled Oxygen Bioreactor, Dinesh Sachdeva

Theses

A computer controlled oxygen bioreactor has been designed to obtain more accurate values for oxygen bioreactor requirements and to optimize oxygen productivity with respect to oxygen concentration. This study solves a specific problem relating to oxygen concentration measurement and bioreactor control. The proposed reactor system is computer controlled to insure a desired oxygen concentration supply to an oxygen consuming reaction or organism. This thesis also explains and illustrates the bioreactor and its computer control system.

The computer controller incorporates oxygen sensing, oxygen measurement and temperature measurement, Electrical circuits have been designed and built for proper signal conditioning, data acquisition, data …

Design Of Governor-Turbine Models In Stability Studies, Vidyanand Swaminathan

Theses

This thesis investigates the effect of hydro governor-turbine models on the steady state stability of an automatically controlled electric power system. Basically two kinds of hydro governor-turbine models, namely, Impulse and Francis type are studied in depth. Design of a compensating network has also been proposed, which can help improve the stability conditions of a power system which employs a poor governor-turbine model.

The power system investigated includes a large sized hydro generating unit connected to an infinite bus via a power network. This generator employs a modern three-channel fast-acting automatic voltage regulator (AVR). For any operating condition, stability results …

Analysis On Dielectric Resonators, Xuan Tu

Theses

This dissertation deals with the studies and analysis of Dielectric Resonators (DR). A shielded dielectric iesonator structure, consisting of the substrate, the spacer, the dielectric resonator and the metallic shielding is modelled theoretically. The theoretical expressions for the resonance fields are derived by using radial-mode matching and axial mode-matching techniques. In these techniques, the structure is divided into partial regions and the fields in each pai tial region are represented in terms of a series of the appropriate modes with unknown coefficients. Matching the adjacent regions yields a system of linear or nonlinear equations — which then are solved. The …

Spectrum Analysis Of Heart Rate Variability, Xuming Wang

Theses

This research investigated the respiratory influence on heart rate variability. The heart rate spectrum was obtained from the heart rate variability signal which was extracted from the electrocardiogram We then studied the magnitude of the respiration peak in the heart rate spectrum and examined the dependence of the magnitude of this peak on breathing frequency, subject and day.

An experiment designed to simultaneously acquire the electrocardiogram and the respiration signal was conducted on ten people ranging from 22 to 55 years of age (3 females, 7 males). Three tests were performed on each subject. In each test, 2 different postures …

Trellis Coded Partial-Response Channels, Kumari Yalamanchili

Theses

Binary partial-response channels with transfer functions (1+D), (1-D) and (1 — D²) are intersymbol-interference channels which find applications in baseband data communications and magnetic recording systems (tapes, discs, compact discs, etc.). In this thesis we develop a coding technique for improving the reliability of digital transmission over noisy partial-response channels with the above transfer functions. We do so by introducing a new concept, called matched encoding, which arises in the context of trellis coding for channels with memory.

We use inner and outer trellis coding of the partial-response channels. The inner codes called matched inner coset codes, are …

Efficient Design Of Trellis Coded Cpfsk, Hsinhsyong Yang

Theses

In this thesis convolutional coded continuous-phase frequency shift keying (CPFSK) is studied.

CPFSK which is a subclass of continuous phase modulation ( CPM ) is a constant amplitude digital modulation scheme with very good spectral characteristics.

A new method, called matched encoding, that combines convolutional codes and CPFSK is studied. With the maximum free Euclidean distance as the optimization criterion, the best combined coded schemes were found for the same rate of the codes and given total number of states in the optimum decoder.

A different method which was suggested by Rimoldi[7], called the decomposition method, is also described in …

Methods Of Achieving High Speed On Data Flow Machines, Chung-Lin Yu

Theses

Simultaneity is a key to high speed and large computation. Assuming hardware components of a given speed, it is the only remaining consideration in achieving raw speed. Simultaneity can be shackled by dependencies, however, and years of hardware and software work have been devoted to understanding the types of dependencies and how they can be obeyed or removed from a computation.

In this thesis, the principles of the data flow machines and the structure of the data flow languages are illustrated. Various methods of achieving high speed are discussed. These methods include streams, Lenient Cons (I-structure), and dependence-driven computation, which …

Image Coding With Switchable Dynamic Quantizers, Shing-Sun Yu

Theses

In this thesis, an image coding scheme based upon dynamic quantizations and Differential Pulse Code Miodulalton (DPCM) is studied for application in digital image transmission. This scheme achieves a degree of data compression, and at the same time, maintains an acceptable degraded Mean Square Error (MSE) in the reproduced image. The image to be transmitted is first divided into blocks and each block is then quantized before transmission. The dynamic quantizations including DPCM) are dynamically utilized in reducing the transmission rate while maintaining a desirable quantization noise level. Results of computer simulation of the proposed scheme demonstrate that the switchable …

Algorithms And Analysis Of Dialogue Time Patterns, Muhammad Saleem Akhtar

Theses

The characteristics of a conversation between two people can be determined not only what they say to each other, but also by the rhythm of their dialogue. Their moods, attitudes and attributes may be conveyed in part by time patterns of the speech. The programs described herein can be useful in exploring the relationship between dialogue time patterns and other psychological aspects of human behavior. The measurements of these time patterns can be quickly, inexpensively, and reliably accomplished by the use of a PC.

The programs described herein are capable of calculating the variabilities, the time durations and frequencies of …

Performance Enhancement & Fault Detection Of Cmos Dynamic Logic For Vlsi, Ashok Arunachalum

Theses

New CMOS dynamic latches are designed which can be used along with conventional dynamic circuits to realize fast pipelined dynamic logic. Also a new method is described for detecting the difficult CMOS Non-classical faults viz. stuck open and stuck on faults. The conventional Domino logic is redesigned to make all the stuck open and stuck on faults detectable.

Unified Study Of Trellis Encoded Correlative-Fm, K. Narendra Bhat

Theses

Trellis encoding of correlative-FM is studied from the point of view of the overall structure, performance, bandwidth occupancy, and complexity. Here, correlative (partial-response) coding is used to improve the bandwidth efficiency of MSK (Minimum-Shift Keying) at the expense of performance. Then, trellis codes are used to improve the error-rate performance of the corresponding correlative-FM scheme with little or no increase in bandwidth occupancy (compared to uncoded MSK). In a sense, this is similar to Ungerboeck's coding for (memoryless) PSK modulation.

A new encoding approach, called matched encoding, is used here that produces trellis coded modulations achieving greater coding gains than …

Non Invasive Monitoring Of Cardiovascular Dynamics Through A Microwave Interferometer, Suresh Chakravarthi

Theses

The microwave interferometer is utilized to pick up vibrations of the anterior (front) chest wall, produced by cardiac activity. This instrument is capable of remotely measuring the vibrations at distances up to four feet through clothing, by using low level microwave energy at 9.3 Ghz. The vibrations picked up from subjects are filtered, and processed through a PC to correlate with EKG signals, and thereby evaluate the instrument as a non-invasive, non-contacting cardiac monitor.

The subjects lie on their back with the microwave energy illuminating their chest, and their cardiovascular dynamics are recorded simultaneously with EKG signals. The EKG is …

Transverse Electric (Te) And Transverse Magnetic (Tm) Mode Conversion In Optically Active (Chiral) Embedded Polymeric Waveguides, Mingdeh Chien

Theses

Wave propagation in an optically active isotropic, polymeric thin film waveguides is studied. The waveguides are fabricated using the dipping method. Thin film layers are composed of a passive PMMA (poly methyl methacrylate) host material and a chiral, optically active, ((s)-(+)-1,1'-Binaphthyl-2,2'-dily hydro phosphate), guest material. Experimental results show about 1° per centimeter rotation of polarization as light propagates through a 1.8cm waveguide. The theoretical analysis of the mode structure and wave propagation in the waveguide are examined using first order coupled mode theory. TE (-4 TM mode converter is a typical application of this investigation.

Implementation Of The Sliding Dictionary Data Compression Algorithm On An At&T Dsp 32 Digital Signal Processor, Shu Fang

Theses

Compared with other data compression algorithms, the sliding dictionary is more practical for implementation in hardware. After a comprehensive study of the algorithm, an on line data compression scheme which uses AT&T DSP 32 Digital Signal Processor has been developed. Assembly language programs for encoder and decoder have been written and tested. The whole compression system has been simulated in a real-time environment and results have been obtained. A quantized coding scheme has been used to increase compression ratio. Separate assembly language programs have been written to implement the quantized coding scheme and tested. Results obtained from real-time simulation are …

One-Dimensional Parametric Inverse Scattering For Lossless Dispersive Media, Frank Gangi

Theses

In this thesis, the effects of high frequency noise on a perturbational inversion algorithm for a stratified dispersive medium are investigated. It is shown that the perturbational algorithm becomes unstable under high frequency noise. The physical origin of this instability is discussed.

In order to enhance the robustness of the perturbational inverse scattering solution, a parametric inversion algorithm is implemented. The improvement by the use of a parametric inversion is given quantitatively by the profile-to-error ratio (PER). Examples of the two-pole and the three-pole reflection coefficients are compared and contrasted.

A Decomposition Algorithm For The State Transition Lattices Of Certain Non-Product Queueing Protocols, Cheng-Kuo Hong

Theses

In this thesis, an algorithm is developed to decompose the state transition lattice of a class of non-product form queueing models. Here only the lattices of regular type A structure are considered. By applying the algorithm, the lattice is decomposed into solvable subsets which can be solved sequentially.

Modelling And Parameter Estimation In Clinical Electrooculography, Shengche Hsu

Theses

The Corneoretinal potential (CRP) was discovered in 1848. Its response to changes in light intensity can provide information relevant in the diagnosis of some retinal degenerative disorders. The indirectly measured CRP is referred to as electro-oculography (EOG). A system for automatic data acquisition and modelling, providing graphic presentation, data processing and file management, has been developed. A linear feedback model is proposed to represent the dynamics of the EOG signal. Model parameters are estimated by the nonlinear least-square method. The effect of measurement time on the reliability of parameter estimation is discussed.

Csma/Cd Lan Performance : Modeling And Simulation In Csim, Nanda K. Kanuri

Theses

A simulation model to analyze the performance of CSMA/CD protocol is developed. CSIM, a process oriented simulation language, is used. Performance measures such as throughput, average delay and maximum delay per packet are presented. System performance is analyzed for different loads, number of stations, and network lengths, with packet length as parameter. By trading off the throughput and delay time, an optium packet length can be selected from simulated performance curves. A general scheme for MAC protocols modeling is provided.

Output Feedback Applied To Observer Based Controller, Nainn-Ping Ke

Theses

This thesis presented the results of an investigation on the stability robustness issues of the Infinite-horizon linear-quadratic-Gaussian (IH-LQG) control system design methodology. The goal of this research deals with the design of Observer based controller using Output Feedback (00F), and this is a new method to solve estimation problems. The primary difference of this method from others is that the estimator is considered as a system. The results of this research shows that the optimal output feedback control law and the optimal state estimator can be designed by the optimal output feedback control method, and shows that the OOF Weighting …

A Cmos Robotic Lan Interface Integrated Circuit Design, Yong-Bin Kim

Theses

This thesis describes the design including specification, schematics,logic and circuit simulation, and standard cell layout for a CMOS mixed-mode I.C. for interfacing sensors into a robotics local area network. The network accepts up to 256 interface chips as nodes in each area. A simple network protocol permits acquisition of digital data from the interface nodes through gateways into ARCNET and MAP.

The sensor chip interfaces directly from analog signals of range 0-1V and 0-20mV. It contains an 8-bit ADC. The application I.C. interfaces to sensors for pressure, tactile stress, humidity, temperature, etc.

Each of the sensor interface node I.C.s is …

A Dynamic Cmos Programmable Logic Device, Praveen K. Parvathala

Theses

This thesis presents the design of a Dynamic CMOS Programmable Logic Device chip (NJIT PLD). The main feature of the chip is its reconfigurability and the provision of a processor interface which makes the chip capable of performing coprocessor like functions. The chip has been designed to be used with the Intel 8088 microprocessor, but may also find stand-alone applications. Provision is made for dynamic reconfiguration of the chip. The configuration data for the chip comes from a serial PROM, to which the chip sends a synchronizing clock. The NJIT PLD is a high performance, digital integrated circuit. It has …

Trellis Encoded M-Ary Partial-Response Schemes, Raju P. Patel

Theses

Convolutional codes can be used to improve the reliability of partial-response channels in a Gaussian noise environment. Multilevel partial-response schemes can be used to increase the information rate in a given bandwidth compared to binary partial-response schemes. This thesis deals with the theory and construction of convolutionally encoded 4-ary partial- response schemes. The free Euclidean distance of the combined trellis of rate-1/2 convolutional code and 4-ary partial-response scheme is found through a computer search, using the Viterbi-algorithm.

The matched encoding concept is also applied to find the conditions for matched encoding for combined trellis of rate-1/2 convolutional codes and 4-ary …

Hardware And Software Designs For Integrated Electrical Engineering Experiments, Sujin Pramojaney

Theses

The interfacing between the various electrical engineering fields is not emphasized in the electrical engineering laboratory; the traditional aim of a laboratory course is to complement a single theoretical course. The object of this thesis is to provide means, hardware and software, that can be used in different system configurations to perform useful industrial tasks. The chosen task is to control electrical machines using a microcomputer. Experiments can be written to be performed by students, using these systems. The emphasize of these experiments can be on the characteristics of a power electronics device, but the device will be seen as …

Network Realizability Approach To Robust Stability Of Discrete-Time Systems Characterized By Polynomials, Sri Indran Rasiah

Theses

In system design, the coefficients of a characterizing polynomial are usually not precisely known but can be bounded from above and below by real numbers. The requirement of robust system design from the stability standpoint demands, then, the guaranteeing of the stability of a set of polynomials.

Stability theorems for continuous-time systems and discrete-time systems, are studied in this report. It is shown that one more condition has to be included into each of the theorem. The revised theorem for continuous-time systems is proved through network realizability theory. The one for discrete-time systems is, then, proved via the use of …

Study Of Ionized Cluster Beam Techniques For Reactive Deposition Of Gallium Nitride Thin Films, Jyh Sheen

Theses

This thesis is divided into two parts. The first part investigates the Ionized Cluster Beam( ICB ) technique through measurements of the energy of ionized gallium beam. The presence of ions and their kinetic energy in the ICB technique is advantageous in the formation process of thin film. The results of retarding potential measurement are comparable with the presence of clusters as large as 500 atoms. The second part examines the formation of gallium nitride thin film. In order to enhance the reaction of gallium and nitrogen, dissociation of molecular nitrogen by microwave discharge method was used to generate atomic …

Firmware Toolkit For Larynx Synchronous D.S.P., Shih-Chieh Su

Theses

During the past ten years, digital signal processing has been an extremely active and dynamic field. Advances in integrated circuit technology and in processor architecture have greatly enlarged the scope of the technical areas to which digital signal processing techniques can be applied. Research in fundamental signal processing techniques and algorithms has led to dramatic improvements in the efficiency of signal processing systems.

This thesis creates a fast and cheap DSP package for 8052AH-BASIC. This is a useful and potential package when we apply research in speech science and medical diagnostics. It exploits the latest software-in-silicon technology to create a …

Electrical Insulation Screening For Reliability, Vinu Sundaresan

Theses

This thesis work includes an investigation on the use of electrical noise for the screening of dielectric sheet material for reliability. Three different high voltage insulation sheet materials, commonly used in power industry, have been studied. These are - Westinghouse Polyester resin coated glass cloth, Dupont ‘NOMEX' aramid calendared paper and a cotton rag commonly known as Fishpaper. Samples of each material have been categorized into low noise and high noise units. Subsequently, these samples were subjected to accelerated life testing.

It is seen that units having high noise are failing quicker compared to low noise units when subjected to …

A Methodology For Designing Spacecraft Onboard Processing Systems, Mohammad Nadeem Ahmad

Theses

A three layer methodology is presented for designing spacecraft onboard computer systems. The system design is perceived as a sequence of three hierarchical layers: the Dedicated Processing Layer, the Application and Support Processing Layer, and the Communications Processing Layer. Each layer implements a distinct set of functions and offers services at different levels of abstraction. As opposed to the ISO/OSI Reference Model, where the prime objective is to implement peripheral interaction between two systems, the layered approach used here is to address the problems in system design itself. The problem is approached in a bottom-up fashion, starting with the description …

Design Of A Temperature Sensor For Gallium Arsenide Ic Applications, Raviprakash Raviprakash Gutala

Theses

This thesis presents the design of a temperature sensor circuit including sensor, differential amplifier, and a memory element for gallium arsenide IC standard cell applications. A standard 1-um depletion-mode GaAs MESFET technology has been used for the design of the circuit. The circuit is intended to be used as a standard cell in GaAs les providing an alarm when the sensor temperature reaches 125 °C. The circuit includes a NAND latch which is set when the chip cell temperature reaches 125 °C. The output of the latch can be sensed by additional circuits (on or off the GaAs chip) which …