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Full-Text Articles in Electrical and Electronics

Modeling Of Vacuum Microelectronic Lateral And Vertical Devices, Qiong Gui May 1991

Modeling Of Vacuum Microelectronic Lateral And Vertical Devices, Qiong Gui

Theses

Vertical and lateral configurations of the vacuum microelectronic device have been modeled using the simulation tools. Both cone and ridge cathode structures are used. Simulation results are compared with experimental data where available. These device structures include cathode, extraction grid, anode, and deflectors. The electric field at the tip of the cathode has been calculated for tip radius as small as 0.1nm. The model used takes into account the effect of potential on all electrodes on the E-field at the cathode tip. Also the effect of cathode geometry on the E-field is detailed.

Static characteristics are based on a new …


Representing Tolerances In A Geometric Modeller, Chih-Tsung Huang May 1991

Representing Tolerances In A Geometric Modeller, Chih-Tsung Huang

Theses

Current geometric modeller contains dimension information only. This thesis describes how tolerance can be added to a geometric modeller. The modeller is based on a hybrid design of the Constructive Solid Geometry (CSG) scheme and Boundary Representation (B-Rep). Various tolerances based on the ANSI standard are considered.


The Neural Network Based Control System For Dynamic Channel Allocation In Pcn Communications, Ching-Yao Huang May 1991

The Neural Network Based Control System For Dynamic Channel Allocation In Pcn Communications, Ching-Yao Huang

Theses

A neural network based control system (NNCS) is adopted in this paper to conduct the channel allocation task in the personal communication networks (PCN). Binary adaptive resonance theory (ART-1) that was modified for pattern matching and provided the corresponding responses is selected as the basic algorithm for the system. Digital portable radio technology can provide reliable access to high quality wireless service for many users. Low power transmission requirement and small cell size configuration that can support more users and diverse services than cellular radio system are the attractive attributes of PCN. Assigning multiple time slots to a user in …


Automatic Infrared And Visual Inspection Of Solder Joints On Pcbs, Jiang Huang May 1991

Automatic Infrared And Visual Inspection Of Solder Joints On Pcbs, Jiang Huang

Theses

This thesis reports the research results of automatic inspection of solder joints on printed circuit boards (PCBs). The previous work on this regard has been advanced significantly in the following three aspects. With the application of some microlens and the principle of geometric optics solder joints of real size are inspected in this work instead of larger simulation solder joints in the previous work. A new set of features is formulated and used for infrared inspection. Consequently, better results have been achieved in this work.

Reasonably good results demonstrate the capability of infrared inspection of solder joints on PCBs. Once …


Direct Recovering Of Composite Surface Using Uoff, Zhesheng Huang May 1991

Direct Recovering Of Composite Surface Using Uoff, Zhesheng Huang

Theses

The research work reported in the thesis is motivated by the problem raised in the computer vision area. It utilizes direct method to recover surface structure of objects in 3-D space from a pair of stereo images. The direct method, compared with optical flow-based approach and feature-based approach, is robust and computationally efficient. However it can only recover planar surface structure so far. A new approach to recover structure from a pair of stereo images based on unified optical flow field (UOFF) is developed recently. It can recover curved surface structure.

In this thesis, the problem of recovering surface structure …


Brushless Dc Motor Speed Control System With Saturation Nonlinearity, Khawja M. Kamal May 1991

Brushless Dc Motor Speed Control System With Saturation Nonlinearity, Khawja M. Kamal

Theses

A study of a three-phase, pulse-width modulated, velocity controlled brushless DC motor speed control system is presented. Previous works on brushless DC drive systems could not explain global instability, due to linear approximations. A complete three-phase system model is presented here, along with a simplified single-phase model, which is similar to a conventional DC motor model. The models incorporate saturation nonlinearity. The brushless DC drive system is analyzed and simulated. Special emphasis is laid on the study of the limit-cycle phenomenon, due to saturation nonlinearity. Global instability is accounted for and relevant parameter regions are established for global stability. The …


Workstation Allocation Schemes For Response Time Improvement In A Multiserver Pc Lan, Asit V. Merchant May 1991

Workstation Allocation Schemes For Response Time Improvement In A Multiserver Pc Lan, Asit V. Merchant

Theses

Microcomputer Local Area Networks have recently become quite popular. Higher demand in term of number of users who contribute a variable amount of load has led to Multiple File servers in a LAN. As a result of variable load, response time at workstations differ significantly depending not only on total load on the network but also on workstation distribution across servers. The goal of this study is to develop schemes to keep response time as low as possible and constant among workstations. This study is based on minimizing response time and containing it or keeping it constant by distributing workstations …


A Comparative Study Of Image Coding Techniques : Filter Banks Vs. Discrete Cosine Transform, Hosam Fawzi Mutlag May 1991

A Comparative Study Of Image Coding Techniques : Filter Banks Vs. Discrete Cosine Transform, Hosam Fawzi Mutlag

Theses

Subband coding of still image frames using Binomial PR-QMF has been presented in this thesis. Simulation results have shown that the performance of subband coding using a low complexity coder is practically the same as the performance of the industry standard (8 x 8) DCT based image coder.

A low bit rate adaptive video coding technique is also introduced in this thesis. The redundancy within adjacent video frames is exploited by motion compensated interframe prediction. The Motion Compensated Frame Difference (MCFD) signals are filtered by employing Binomial PR-QMF structure into four subbands. Then, the subbands are quantized using an efficient …


Minimized Test Patterns For Sequential Logic, Chetan Patel May 1991

Minimized Test Patterns For Sequential Logic, Chetan Patel

Theses

This thesis presents a novel algorithmic approach which can be used to reduce the total test pattern lengths for testing a sequential logic circuit. Test generation for sequential circuits has long been recognized as a difficult task. Several approaches have been made in the past to solve the problems of test generation stage for sequential circuits but they were either an extension of the classical D-algorithm or based on the random techniques. When number of states of the sequential circuit is larger and the test demands long input sequences, they can be quite ineffective for the test generation. The STALLION …


Synthesis And Characterization Of Boron Nitride Masks For X-Ray Lithography, Venkat Paturi May 1991

Synthesis And Characterization Of Boron Nitride Masks For X-Ray Lithography, Venkat Paturi

Theses

Boron nitride thin films were deposited on silicon and fused quartz substrates by low pressure chemical vapor deposition using liquid precursor source consisting of Triethyl amine borane complex over a temperature range of 600-900°C. In the range of 600-800°C, the deposition rate, measured at a constant pressure of 0.35 Torr and flow rate of 30 sccm, was observed to follow an Arrhenius behavior yielding an activation energy of 11 kcal/mol. In the temperature range of 800-900°C, the addition of ammonia to Triethylamineborane complex produced films that are stoichiometric, as estimated by RBS measurements, and hydrogen free as determined by Infrared …


Analysis And Implementation Of A Navigation System Using Vanishing Points In A Generalized Environment, Rolf Schuster May 1991

Analysis And Implementation Of A Navigation System Using Vanishing Points In A Generalized Environment, Rolf Schuster

Theses

The development of accurate sensors is of crucial importance in navigation of mobile autonomous robots. The following master's thesis analyzes the use of vanishing points for robot navigation. Parallel lines in the environment of the robot are used to compute vanishing points which serve as a reference for guiding a robot. To accomplish the navigation tasks, three subtasks are to be performed: detection of straight lines, computation of vanishing points, and robot navigation with vanishing points.

An edge detection algorithm is presented that combines Sobel and Laplacian of Gaussian operators. The algorithm preserves the precision of the Laplacian of Gaussian …


Connected Component Labelling On A Pair Of Parallel Systems, Imran Shahid May 1991

Connected Component Labelling On A Pair Of Parallel Systems, Imran Shahid

Theses

Hypercubes and meshes are of the most successful parallel processing structures and are widely used in image processing applications. The mesh is a natural multiprocessor architecture for image processing because an N x N image can be directly mapped onto a mesh of N x N PEs (processing elements), holding each PE responsible for one pixel, with neighboring PEs responsible for neighboring pixels. Thus, local operations can be performed on the image, or local image features can be detected in parallel, with each processor simultaneously accessing its neighbor and computing the appropriate function for its neighborhood. Meshes and several other …


Tisi2/N+/P Silicon Junction Formation By Ion Implantation Through Metal Technique, Ying Wu May 1991

Tisi2/N+/P Silicon Junction Formation By Ion Implantation Through Metal Technique, Ying Wu

Theses

Experimental analysis, modeling and simulation of the formation and electrical characterization of TiSi2/n+/p-Si shallow junctions are presented here. The formation of shallow n+-p junction, by ion implantation of As+ through Ti films evaporated on p-Si substrates followed by Rapid Thermal Annealing ( RTA ) and conventional furnace annealing has been performed in these experiments. Structural techniques such as Secondary Ion Mass Spectroscopy ( SIMS ) and Rutherford Backscattering spectroscopy ( RBS ) experiments have been employed to characterize the devices, and RUMP simulator was used to analyze and interpret the RBS data. Current-voltage …


Novel Artificial Dielectric Plannar Waveguides, Jialing Yang May 1991

Novel Artificial Dielectric Plannar Waveguides, Jialing Yang

Theses

An artificial dielectric is a composite material consisting of a dielectric with a large number of conducting particles arranged in a three-dimensional pattern. The particle dimensions are smaller than the optical wavelength of interest. In this thesis, the theoretical and experimental results of some novel artifical dielectric planar waveguide structures are presented. By comparing near field intensity profile measurements from various waveguide structures, we have shown that by adding small clusters of the conductor material into the waveguide we can tailor the mode profile of the waveguide. Also, we were able to fabricate waveguides on a substrate with relatively higher …


A New Approach To Motion Analysis From A Sequence Of Stereo Images, Lin Zhou May 1991

A New Approach To Motion Analysis From A Sequence Of Stereo Images, Lin Zhou

Theses

A new approach to motion analysis from a sequence of stereo images is presented in this thesis. Based on a four-frame model, a new concept of unified optical flow field has been developed recently [3]. It is a generalization of the optical flow in stereo imagery. A set of fundamental equations is established to characterize the unified optical flow field. Another set of equations is then derived from which 3-D motion can be reconstructed via the use of the field quantities of the unified optical flow field. In this thesis, the implementation of the approach is conducted. The simulation and …


Bad Data Identification In Power Systems, Shichun Zou May 1991

Bad Data Identification In Power Systems, Shichun Zou

Theses

Two classes of bad data (BD) identification methods in power system state estimation are studied.

The first class is the perturbation method. In this method, the obtained measurements are perturbed a few times. Each time a state is obtained from which measurement corrections are calculated. The statistics of the corrections corresponding to a BD are different from those corresponding to a healthy data. The method uses those differences for identification purposes.

The effectiveness of different indicators is studied. These include the normalized residual, the weighted residual, and residuals incorporating the statistics of the corrections.

The success rate of using the …


Performance Analysis Of Symbol Timing Recovery Circuits Employed In Digital Communications Systems, Elisha Yegal Bar-Ness May 1991

Performance Analysis Of Symbol Timing Recovery Circuits Employed In Digital Communications Systems, Elisha Yegal Bar-Ness

Theses

An analytical approach is presented for the jitter performance of a timing recovery circuit consisting of a prefilter, a zero-memory nonlinear device, and a narrow band postfilter tuned to the pulse repetition frequency. Assuming first a squarer type of nonlinearity, analytical expressions for the rms jitter in the timing wave are obtained as a function of the pre and post filtering characteristics. These expressions are suitable for judging the case where the baseband signal is bandlimited. Also for some specific examples, the jitter performance of this kind of STR circuit is evaluated.

Secondly, a general type of nonlinerity is assumed, …


Multistage Interconnection Networks : Improved Routing Algorithms And Fault Tolerance, Kuo-Yu Chen May 1991

Multistage Interconnection Networks : Improved Routing Algorithms And Fault Tolerance, Kuo-Yu Chen

Theses

Multistage interconnection networks for use by multiprocessor systems are optimal in terms of the number of switching element, but the routing algorithms used to set up these networks are suboptimal in terms of time. The network set-up time and reliability are the major factors to affect the performance of multistage interconnection networks. This work improves routing on Benes and Clos networks as well as the fault tolerant capability. The permutation representation is examined as well as the Clos and Benes networks. A modified edge coloring algorithm is applied to the regular bipartite multigraph which represents a Clos network. The looping …


Task Scheduling For Fms Based On Genetic Algorithm, Hung-Yuan Li May 1991

Task Scheduling For Fms Based On Genetic Algorithm, Hung-Yuan Li

Theses

A Flexible Manufacturing System (FMS) consisting of p automated guided vehicles (AGV's), m workstations and n tasks is studied. The main problem investigated in this thesis is to find an optimal or suboptimal task scheduling for p AGV's among m workstations to complete n tasks.

An efficient approach based on genetic algorithms has been designed and implemented to solve the problem of task scheduling for a FMS. Near-optimal, or even optimal, task scheduling is accomplished by genetic algorithms. Simulation results on the algorithm are also discussed.


Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Services In The Token Ring Network, Hong Wang May 1991

Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Services In The Token Ring Network, Hong Wang

Theses

Ordinary service and exhaustive service are two major alternatives of scheduling policies considered in providing access to token ring networks. Results to date have shown that exhaustive service results in more delay to lightly loaded stations in asymmetric traffic while ordinary service wastes time in circulating the token after each transmission. This work presents a new token passing protocol, called adaptive service, in which the token holding time is dynamically changing; in this way, it provides a fair compromise between exhaustive and ordinary service. The simulation results show that in asymmetric traffic, adaptive service gives improvement on the local delay …


Performance Evaluation In Terms Of Congestion And Flow Control Of Interconnected Token Ring Local Area Networks, Muhammad Salim Raza May 1991

Performance Evaluation In Terms Of Congestion And Flow Control Of Interconnected Token Ring Local Area Networks, Muhammad Salim Raza

Theses

In an interconnected network, if user demands are allowed to exceed the system capacity, unpleasant congestion effects occur which rapidly neutralize the delay and efficiency advantages. Congestion can be eliminated by using an appropriate set of traffic monitoring and control procedures called flow control procedures. This thesis first investigates the major technical concepts underlying the token-ring technology; performance and flow control issues and then gives an approximate analytical solution in terms of mean end-toned delay in a system of token-ring local area network interconnected through bridges. The analytical solution is based on an approximation of the mean end-to-end delay in …


A Parallelogram Four-Frame Model In 3-D Motion And Structure Recovery Using Unified Optical Flow Field Approach, Zhichun Lin May 1991

A Parallelogram Four-Frame Model In 3-D Motion And Structure Recovery Using Unified Optical Flow Field Approach, Zhichun Lin

Theses

In this paper a new concept of the unified optical flow field (UOFF) for 3 D motion analysis from a stereo image sequence is implemented which is an extension of the temporal optical flow formulations developed by Horn and Schunck. A four frame model is established and a spatial optical flow is also introduced.

In order to alleviate the problem of the strict requirement of two identical sensors in common stereo imagery a new imaging system is presented in this paper that needs only one camera, two plane mirrors and two switches to generate a phase shifted binocular sequence of …


A Cmos Logic Circuit To Reduce Substrate Current/Hot Carrier Effect, Tejinder K. Jaswal May 1991

A Cmos Logic Circuit To Reduce Substrate Current/Hot Carrier Effect, Tejinder K. Jaswal

Theses

A new C-MOS NAND and CMOS full adder logic circuits which reduces hot carrier problems are discussed. The application of new circuit lowers the channel electric field in N-MOSFET during switching transient and leads to suppression of the N-MOSFET substrate current. The simulation results shows that about 3.99 and 3.75 times smaller peak substrate current are obtained in C-MOS NAND and adder with new circuit compared to the conventional logic circuits. These logic circuits also gives better noise and shows shorter rise and fall times. The new concept provides highly reliable logic circuits without any change of device structure or …


Parallel Implementation Of Spatial Domain Image Processing Algorithms On The Mesh Connected Computer Simulator, Adury Devi Prasad May 1991

Parallel Implementation Of Spatial Domain Image Processing Algorithms On The Mesh Connected Computer Simulator, Adury Devi Prasad

Theses

The performance of conventional computers in image processing applications is known to be inadequate due to the enormous computational requirements. Almost all image processing applications can be implemented in parallel. This thesis is the parallel implementation of neighborhood averaging and edge detection by the Sobel and Laplacian operators on the Mesh Connected Computer Computer Simulator (MCCS), a package developed at NJIT to study the behavior of SIMD machines. Expressions for speedup, utilization and efficiency have been derived. Suggestions for further improvements that can be incorporated in MCCS and its instruction set have been made.


Linear Regulator And Singular Control In Generalised State Space System, Devesh Kumar Thodimela May 1991

Linear Regulator And Singular Control In Generalised State Space System, Devesh Kumar Thodimela

Theses

The problem of unconstrained optimal control of continuous-time singular systems is considered, by straight forward extension of some well-known equations derived for ordinary state-space systems by variational calculus and by the aid of the simplest algebraic and matrix tools: In this thesis, the interest is restricted to the case where the system is to be driven from a fixed initial state to a fixed final state as well as free final state tf while minimizing a performance index of the form

J = 1/2 ∫tf to <( Y - Yi), Q ( Y - Yi) > dt

Subject …


Simulation Of Voice And Data Integration, Urmila S. Patel May 1991

Simulation Of Voice And Data Integration, Urmila S. Patel

Theses

A simulation model of integrated voice and data is developed. The data packets are transmitted during voice inactivity (i.e. silence duration). A statistical model of voice (talkspurt) and silence duration is generated. inter-arrival time between data packets is modeled using geometrical distribution. The data traffic statistics is simulated for a given voice activity model and various data packet arrival rates. Four important results are obtained by performing this simulation: 1. Average data packet delay versus arrival rate. 2. The optimal ratio of data packet arrival rate to average data packet delay. 3. Probability of wait time for various data packet …


Decomposing Non-Product Form Queueing Lattices Through Autorouting With A* Algorithm, Chun-Chang Yu Jan 1991

Decomposing Non-Product Form Queueing Lattices Through Autorouting With A* Algorithm, Chun-Chang Yu

Theses

Direct solution techniques are expensive for the state transition lattice of a class of non-product form queuing modes. In this thesis, Autorouting with A* algorithm is adapted to decompose it as solvable subsets which can be solved sequentially and independently. Autorouting with A* algorithm is heuristics in problem solving. It also is one of a class of global optimization problems that are difficult to solve. Some queuing modes of type A will be decomposed in this thesis through Autorouting with A* algorithm.


Direct Schottky Injection Image Sensors, Subramanyam V. Ayyagari Jan 1991

Direct Schottky Injection Image Sensors, Subramanyam V. Ayyagari

Theses

This thesis describes the analysis and simulations of Direct Schottky Injection (DSI) imagers which have 100% fill factor. Frame transfer (FT) and interline transfer (IT) DSI imager structures have been investigated. Theoretical Poisson solution for the PT and P-NP FT-DSI structures is presented, which closely agrees with simulation results. Simulation for frame transfer FT-DSI imagers has been done in SUPREM III since 1-D effects are more dominant. Single carrier transit time for both the structures were estimated from the electric fields.

Simulations of IT-DSI structures was done using PISCES llb, to get the local electric fields, which define the directionality …


Multiresolution Techniques : Laplacian Pyramid Coding And Its Comparison With Subband Coding, Danmei Chang Jan 1991

Multiresolution Techniques : Laplacian Pyramid Coding And Its Comparison With Subband Coding, Danmei Chang

Theses

The multiresolution pyramid and related structures have been developed as intermediate representations between the purely frequency domain and purely spatial domain. In this thesis. we discuss two important pyramid structures which are often used in multiresolution representation: Laplacian pyramid and subband coding.

Laplacian pyramid. a typical pyramid structure, is studied in detail. By means of software implementation. we obtain a comprehensive understanding of its features and applications in image representation and data compression. Several modifications of pyramid structure are used to compress the data dynamic range, reduce the computational complexity and improve performance. Performance of the conventional Laplacian pyramid and …


A Machine Vision System With Remote Host, Chieyeon Jason Chen Jan 1991

A Machine Vision System With Remote Host, Chieyeon Jason Chen

Theses

The modem plays an important role in data communication using the Public Swiched Telephone Network. In this thesis, the modem function is merged into a low cost machine vision system based on the Motorola 68HC11. Evalation Board The system comprises the intelligent machine vision con- troller and a remotely located host computer, such as an IBM-PC. It, supports extra long distance communication capability so that the controller and the host can be anywhere in the world where then is a telephone line. Because of the limit of a 2100 bps modem, soft ware data compression is implemented here to save …