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A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer Jan 2000

A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer

Conference papers

The ability of proportional integral (PI) and proportional integral derivative (PID) controllers to compensate many practical industrial processes has led to their wide acceptance in industrial applications. The requirement to choose either two or three controller parameters is perhaps most easily done using tuning rules. A summary of tuning rules for the PID control of single input, single output (SISO) processes with time delay is provided in this paper.

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New Free-Space Multistage Optical Interconnection Network And Its Matrix Theory, Fengguang Luo, Mingcui Cao, Anjun Wan, Jun Xu, Xinjun Zhou, Cong Deng Jan 2000

New Free-Space Multistage Optical Interconnection Network And Its Matrix Theory, Fengguang Luo, Mingcui Cao, Anjun Wan, Jun Xu, Xinjun Zhou, Cong Deng

Electro-Optics and Photonics Faculty Publications

A new free-space multistage optical interconnection network which is called the Comega interconnection network is presented. It has the same topological construction for the cascade stages of the Comega interconnection. The concept of the left Comega and the right Comega interconnection networks are given to describe the whole Comega interconnection network. The matrix theory for the Comega interconnection network is presented. The route controlling of the Comega interconnection network is decided based on the matrix analysis. The node switching states in cascade stages of the 8 by 8 Comega interconnection network for the route selection are given. The data communications …

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Integrated Floorplanning And Buffer Insertion For Bus-Based Microprocessor Designs, Faran Rafiq Jan 2000

Integrated Floorplanning And Buffer Insertion For Bus-Based Microprocessor Designs, Faran Rafiq

Dissertations and Theses

In this thesis, we propose a novel algorithm for the interconnect driven floorplanning problem that integrates bus planning with floorplanning. This integrated floorplanner is intended for bus-based designs in which the layout is considered to be a set of blocks connected through buses. Each bus consists of a large number of wires. Our floorplanner allocates the exact location and shape of the interconnect (both above and between the circuit blocks) and ensures routability as well as optimizes the timing goals. Our experiments with benchmarks clearly show the superiority of integrated floorplanning approach over the classical floorplan-analyze-and-then-refloorplan approach. Our initial results …

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Doppler Estimation Using A Coherent Ultrawide-Band Random Noise Radar, Ram M. Narayanan, Muhammad Dawood Jan 2000

Doppler Estimation Using A Coherent Ultrawide-Band Random Noise Radar, Ram M. Narayanan, Muhammad Dawood

Department of Electrical and Computer Engineering: Faculty Publications

The University of Nebraska has developed an ultrawide- band (UWB) coherent random noise radar operating over the 1–2 GHz frequency range. The system achieves phase coherence by using heterodyne correlation of the received signal with a time-delayed frequency-shifted replica of the transmit waveform. Knowledge of the phase of the received signal and its time dependence due to target motion permits the extraction of the mean Doppler frequency from which the target speed can be inferred. Theoretical analysis, simulation studies, and laboratory measurements using a microwave delay line showed that it was possible to estimate the Doppler frequency from targets with …

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An Efficient Algorithm To Determine The Periodic Steady-State Solutions Of Nonlinear Systems Using Extended Spectral Analysis, Gülay Tohumoğlu Jan 2000

An Efficient Algorithm To Determine The Periodic Steady-State Solutions Of Nonlinear Systems Using Extended Spectral Analysis, Gülay Tohumoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

A new method for the solution of nonlinear periodic systems was developed. It avoids the time domain calculations of the whole network equations. In the proposed method, by forming the augmented network as linear and nonlinear subnetworks these subnetworks are formulated in complex frequency and time domain respectively. Using spectral analysis the steady-state periodic solution of the whole nonlinear network is reached by an iterative approach. The method can be applied efficiently to weak and strong nonlinear circuits equally well. When we divide the network into a large linear subnetwork and a small nonlinear subnetwork, this method can be applied …

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Applications Of Wavelet Transforms In Biomedical Optoacoustics, Zibiao Wei, Shujun Yang, Amin N. Dharamsi, Barbara Hargrave Jan 2000

Applications Of Wavelet Transforms In Biomedical Optoacoustics, Zibiao Wei, Shujun Yang, Amin N. Dharamsi, Barbara Hargrave

Biological Sciences Faculty Publications

We discuss the utility of wavelet transform methods in signal processing in general, and in particular, demonstrate the technique in optoacoustic applications. In several optoacoustic experiments with different samples, we have successfully enhanced the signal to noise ratios. Wavelet transforms optimize resolution by utilizing a tailored, variable time-window in different frequency regions. The technique's great advantage lies in the fact that the wavelet transform adds some redundancy to the original signal, and some desired features can be enhanced in the transformed space. In addition, proper choice of the basis set allows a sparse representation of the signal. Therefore, even when …

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Additional Quality Factors For The World Wide Web., Ronan Fitzpatrick Jan 2000

Additional Quality Factors For The World Wide Web., Ronan Fitzpatrick

Conference papers

Web site development is maturing from the enthusiastic experimental practice of early years to a more professional discipline, addressing the needs of Web site visitors and owner organisations. Quality is central to this maturing and it is necessary to have a full understanding of the meaning of quality in the context of the ever-changing Web. This paper identifies five new quality factors for the Web (visibility, credibility, intelligibility, engagibility and differentiation), together with their characteristics and a checklist of enablers, which can be used by specifiers, designers, developers and evaluators to create quality Web sites.

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Decentralized Online Neuro-Identification Of Turbogenerators In A Multi-Machine Power System, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2000

Decentralized Online Neuro-Identification Of Turbogenerators In A Multi-Machine Power System, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a new and a novel technique based on Artificial Neural Networks (ANNs) for nonlinear model of turbogenerators in a multi-machine power system. Only local measurements are required by each ANN in this new method, and hence it is called decentralized neuro-identificiation. Each turbogenerator in the power system is quipped with an ANN which is able to identify (or model) its particular turbogenerator from moment to moment This information can then be used by a second ANN at each generator to enable effective control of the nonlinear non-stationary process under all operating conditions. Simulation results are presented in …

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Pid Compensation Of Time Delayed Processes: A Survey, Aidan O'Dwyer Jan 2000

Pid Compensation Of Time Delayed Processes: A Survey, Aidan O'Dwyer

Conference papers

An extensive literature exists on the PID compensation of time delayed processes. It is possible to identify themes that are common to many of the available techniques. The intention of the paper is to provide a framework against which the literature may be viewed.

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Power Education At The Crossroads, Badrul H. Chowdhury Jan 2000

Power Education At The Crossroads, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

To meet the demands of designing and running far more complex and highly integrated electricity systems, a new kind of power engineer is needed. In this paper, the author describes how, though students tend to favor higher-tech and more lucrative fields than power Engineering; reports of the discipline''s demise are exaggerated

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Voice Command Controller, Hoang Nghia Nguyen Jan 2000

Voice Command Controller, Hoang Nghia Nguyen

Theses : Honours

Signal processing technology has been strongly developed and it has attracted interest from scientists and engineers around the world from the last decade. Speech synthesis and speech recognition are particular topic in the field that have been widely used and developed in many different area such as business, controlling, education and entertainment. The project's main objective is to study and develop an application program with the Speech SDK through design and implementation of Tele-Control system based on the commercial product of National Semiconductor: Carrier-Current Transceiver (LM 1893) and Speech development kit (Speech SDK4.0) from Microsoft Corporation. The project is suitable …

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Vhdl Design And Simulation For Embedded Zerotree Wavelet Quantisation, Hung Huynh Jan 2000

Vhdl Design And Simulation For Embedded Zerotree Wavelet Quantisation, Hung Huynh

Theses : Honours

This thesis discusses a highly effective still image compression algorithm – The Embedded Zerotree Wavelets coding technique, as it is called. This technique is simple but achieves a remarkable result. The image is wavelet-transformed, symbolically coded and successive quantised, therefore the compression and transmission/storage saving can be achieved by utilising the structure of zerotree. The algorithm was first proposed by Jerome M. Shapiro in 1993, however to minimise the memory usage and speeding up the EZW processor, a Depth First Search method is used to transverse across the image rather than Breadth First Search method as initially discussed in Shapiro's …

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Cellular Automata Study Of The Feasibility Of A Parallel Optical Computer, Jason Robert Lane Jan 2000

Cellular Automata Study Of The Feasibility Of A Parallel Optical Computer, Jason Robert Lane

Masters Theses

"The speed of modern electronic computers has inherent design limitations which will soon be reached. A possible substitute is the optical computer. In this project, the feasibility of the optical computer is explored by designing and building a parallel optical system. This system is used to test the basic principles that would govern a parallel optical computer. The system is based on the principle of cellular automata, which is a simulation technique used to study interactions of objects in a system. The following goals were set. The system would be based on cellular automata. A one-dimensional array with nine cells, …

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Fourier Based Three Phase Power Metering System, Scott C. Smith, M. J. Devaney Jan 2000

Fourier Based Three Phase Power Metering System, Scott C. Smith, M. J. Devaney

Electrical and Computer Engineering Faculty Research & Creative Works

The increased application of higher frequency nonlinear loads, such as electronic fluorescent ballasts and higher speed adjustable drives, has resulted in the need to monitor the higher power system harmonics which were largely ignored in earlier power monitors. Addressing this need requires a meter with substantially higher sample rate and greater computational power. This paper describes a zero-blind, three-phase, three-element power meter that samples three voltages and four currents at 256 points per cycle. The instrument relies on the FFT to compute real and reactive power at each harmonic and reports total real, reactive, and distortion power on each phase. …

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Comparison Of Text-Dependent Speaker Identification Methods For Short Distance Telephone Lines Using Artificial Neural Networks, Ganesh K. Venayagamoorthy, N. Sundepersadh Jan 2000

Comparison Of Text-Dependent Speaker Identification Methods For Short Distance Telephone Lines Using Artificial Neural Networks, Ganesh K. Venayagamoorthy, N. Sundepersadh

Electrical and Computer Engineering Faculty Research & Creative Works

The transition to democracy in South Africa has brought with it certain challenges. The main challenge is to get rid of crime and corruption. The paper presents a technique to combat white-collar crime in telephone transactions by identifying and verifying speakers using artificial neural networks (ANNs). Results are presented to show that speaker identification is feasible and this is illustrated with two different types of ANN architectures and with two different types of characteristic features as inputs to ANNs.

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A Probabilistic Analysis Of The Ratio Spectrum, M. D. Skowronski, J. G. Harris Jan 2000

A Probabilistic Analysis Of The Ratio Spectrum, M. D. Skowronski, J. G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, Lim and Harris (see IEEE International Symposium on Circuits and Systems, p.277-80, June 1998) developed a novel spectral representation called the ratio spectrum. The ratio spectrum is formed by taking the ratio of the power of a low pass filtered signal to the power of the original unfiltered signal for all filter cutoff frequencies. Features extracted from the ratio spectrum have proven to be promising for phoneme recognition and speech compression. In this work we have shown that the ratio spectrum feature sets are competitive with standard feature sets used for automatic speech recognition. To understand the underlying properties …

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Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna Dec 1999

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …

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Results Using An Alternative Approach To Channel Equalization Using A Pattern Classification Strategy, Frank M. Caimi, Gamal A. Hassan Dec 1999

Results Using An Alternative Approach To Channel Equalization Using A Pattern Classification Strategy, Frank M. Caimi, Gamal A. Hassan

Electrical Engineering and Computer Science Faculty Publications

In underwater acoustic communication, (ACOMMs), ocean surface and bottom conditions create multi path propagation's for the transmitted signal that result in Inter symbol Interference (ISI) at the receiver. Generally, Equalization, Diversity IBeam forming, and Channel Coding are three independent techniques that are used to improve received signal quality. Equalization compensates for ISI created by a band-limited, time-dispersive channel through implementation of specialized filtering schemes within the receiver. The coefficients of the equalizer need to be continuously adjusted to compensate for the variability in the channel. Since the number of states required by the equalizer (or beam former) is finite, and …

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Approximation And Optimization Of An Auditory Model For Realization In Vlsi Hardware, Samuel L. Sangregory Dec 1999

Approximation And Optimization Of An Auditory Model For Realization In Vlsi Hardware, Samuel L. Sangregory

Theses and Dissertations

The Auditory Image Model (AIM) is a software tool set developed to functionally model the role of the ear in the human hearing process. AIM includes detailed filter equations for the major functional portions of the ear. Currently, AIM is run on a workstation and requires 10 to 100 times real-time to process audio information and produce an auditory image. An all-digital approximation of the AIM which is suitable for implementation in very large scale integrated circuits is presented. This document details the mathematical models of AIM and the approximations and optimizations used to simplify the filtering and signal processing …

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Economic Dispatch And Optimal Sizing Of Battery Energy Storage Systems In Utility Load-Leveling Operations, Chin H. Lo, Max Darwin Anderson Dec 1999

Economic Dispatch And Optimal Sizing Of Battery Energy Storage Systems In Utility Load-Leveling Operations, Chin H. Lo, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

Battery energy storage (BES) systems show promise of savings for both the utility and the customer. An algorithm combining multi-pass dynamic programming (MPDP) with a time-shift technique has been developed for two purposes: economic dispatch of BES and finding optimal BES power and energy capacities in a power system. Due to the daily cyclic nature of the load curve, a 168-hour load curve is decomposed into seven 24-hour subsections for easy management. Each subsection is treated independently. Decomposition can save computation time and computer memory. A time-shift technique provides better starting state values and improves the finding process of the …

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Multimedia Databases, S. R. Subramanya Dec 1999

Multimedia Databases, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

The acquisition, generation, storage and processing of multimedia data in computers and transmission over networks have grown tremendously. Databases have been developed to cope with huge amounts of data in different applications. Multimedia databases (MMDB) are essential for efficient management and effective use of this data. They are however still in their infancy. Most current MMDB system prototypes are closely bound to narrow application areas. Experiences gained from developing and using novel multimedia will help advance the multimedia database technology.

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Method For Testing Field Programmable Gate Arrays, Charles E. Stroud, Miron Abramovici Nov 1999

Method For Testing Field Programmable Gate Arrays, Charles E. Stroud, Miron Abramovici

Electrical and Computer Engineering Faculty Patents

A method of testing field programmable gate arrays (FPGAs) includes the step of configuring programmable logic blocks of the FPGAs for completing a built-in self-test. Specifically, the FPGA under test may be configured to act as an iterative logic array wherein a first group of programmable logic blocks are configured as test pattern generators, output response analyzers and helper cells, and a second group of programmable logic blocks are configured as blocks under test. The blocks under test are then repeatedly reconfigured in order to completely test each block under test in all possible modes of operation. The first and …

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Accuracy Of Scatterometer-Derived Winds Using The Cramer-Rao Bound, David G. Long, Travis E. Oliphant Nov 1999

Accuracy Of Scatterometer-Derived Winds Using The Cramer-Rao Bound, David G. Long, Travis E. Oliphant

Faculty Publications

A wind scatterometer makes measurements of the normalized radar-backscatter coefficient O of the ocean surface. To retrieve the wind, a geophysical model function (GMF), which relates O to the near-surface wind, is used. The wind vector can be estimated using maximum-likelihood techniques from several O measurements made at different azimuth angles. The probability density of the measured O is assumed to be Gaussian with a variance that depends on the true O and therefore, depends on the wind through the GMF. With this model for wind estimation, the Cramer-Rao (C-R) bound is derived for wind estimation, and its implications for …

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Crossover Photonic Switching Network With Cmos/Seed Smart Pixel Device And 2d Optical Fiber Bundle Array, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Deming Liu Nov 1999

Crossover Photonic Switching Network With Cmos/Seed Smart Pixel Device And 2d Optical Fiber Bundle Array, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Deming Liu

Electro-Optics and Photonics Faculty Publications

A 16 X 16 Crossover photonic switching network with hybrid integrated CMOS/SEED smart pixel device and 2D optical fiber bundle array I/O access device is reported in this paper. SEEd array devices ar used as light receivers and transmitters, while CMOS devices make efficient logical processing. 4 X 40 2D multilayer optical fiber bundle arrays are fabricated and are used as I/O access devices in the crossover photonic switching network. The center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125micrometers , and the spacing between adjacent layers is 250micrometers . Displacing …

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Low-Frequency Noise In N-Gan With High Electron Mobility, M. E. Levinshtein, S. L. Rumyantsev, D. C. Look, R. J. Molnar, M. Asif Khan, Grigory Simin, V. Adivarahan, M. S. Shur Nov 1999

Low-Frequency Noise In N-Gan With High Electron Mobility, M. E. Levinshtein, S. L. Rumyantsev, D. C. Look, R. J. Molnar, M. Asif Khan, Grigory Simin, V. Adivarahan, M. S. Shur

Faculty Publications

We report on the results of measurements of low frequency noise in n-type gallium nitride (GaN) grown on sapphire with 300 K electron mobility of 790 cm2/V s. The noise spectra have the form of 1/f noise with a Hooge parameter α of approximately 5×10−2. This value of α is two orders of magnitude smaller than that observed before in n-GaN. The obtained results show that the level of flicker noise in GaN, just like that in GaAs and Si, strongly depends on the structural perfection of the material (the amplitude of the 1/f …

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Temperature Dependence Of Electrical And Optical Modulation Responses Of Quantum-Well Lasers, T. Keating, Xiaomin Jin, Shun Lien Chuang, K. Hess Oct 1999

Temperature Dependence Of Electrical And Optical Modulation Responses Of Quantum-Well Lasers, T. Keating, Xiaomin Jin, Shun Lien Chuang, K. Hess

Electrical Engineering

We present theory and experiment for high-speed optical injection in the absorption region of a quantum-well laser and compare the results with those of electrical injection including the carrier transport effect. We show that the main difference between the two responses is the low-frequency roll-off. By using both injection methods, we obtain more accurate and consistent measurements of many important dynamic laser parameters, including the differential gain, carrier lifetime, K factor, and gain compression factor. Temperature-dependent data of the test laser are presented which show that the most dominant effect is the linear degradation of differential gain and injection efficiency …

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Theory Of Photon Coincidence Statistics In Photon-Correlated Beams, Majeed M. Hayat, Sergio N. Torres, Leno M. Pedrotti Oct 1999

Theory Of Photon Coincidence Statistics In Photon-Correlated Beams, Majeed M. Hayat, Sergio N. Torres, Leno M. Pedrotti

Electrical and Computer Engineering Faculty Research and Publications

The statistics of photon coincidence counting in photon-correlated beams is thoroughly investigated considering the effect of the finite coincidence resolving time. The correlated beams are assumed to be generated using parametric downconversion, and the photon streams in the correlated beams are modeled by two partially correlated Poisson point processes. An exact expression for the mean rate of coincidence registration is developed using techniques from renewal theory. It is shown that the use of the traditional approximate rate, in certain situations, leads to the overestimation of the actual rate. The error between the exact and approximate coincidence rates increases as the …

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Evaluation Of The Transport Properties Of Gasb For Bipolar Applications Through Monte Carlo Simulations, Damayanthi Palaniappan Oct 1999

Evaluation Of The Transport Properties Of Gasb For Bipolar Applications Through Monte Carlo Simulations, Damayanthi Palaniappan

Electrical & Computer Engineering Theses & Dissertations

GaAs is currently the semiconductor material of choice for high speed, low power applications. Its electronic transport properties are superior to almost all other semiconductors. It is also used in a variety of bipolar applications such as photodetectors and photo-mixers. However, as is well known, the hole mobility and related transport parameters of GaAs are not very good. This is a serious drawback, and poses a potential problem for all applications involving bipolar conductivity. In order to increase the high :frequency limits and high-speed capability of bipolar devices, the choice of an alternative material, therefore, becomes necessary. An important first …

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Implementation And Performance Of Error Correction Codes For High-Speed Computer Networks, Jochen Spengler Sep 1999

Implementation And Performance Of Error Correction Codes For High-Speed Computer Networks, Jochen Spengler

Dissertations and Theses

During the transmission of data there is always a possibility that errors occur and some pieces are modified. If the receiver detects an error it either sends a request for retransmission or, like in networks using Ethernet, it does not send an acknowledgment for the erroneous frame. In this case the sender waits a certain time and retransmits the frame. With the development of faster computer networking hardware and the need for more real-time applications, these errors have become a major concern. Long retransmission latencies and the need for large memories for buffering drive the development of more reliable network …

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Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu Sep 1999

Optoelectronic Switching Network With 2d Optical Fiber Bundle Array I/O Access Device, Fengguang Luo, Mingcui Cao, Qiaoyan Hu, Anjun Wan, Jun Xu, Cong Deng, Yuan-Zhong Xu

Electro-Optics and Photonics Faculty Publications

An optoelectronic switching network with 2-D optical fiber bundle arrays I/O access device is presented in this paper. An optoelectronic recirculating Banyan network based on CMOS/SEED smart pixel device is used in this configuration. Thirty-two X two single-mode fiber bundle array and 32 X 2 multi- mode fiber bundle array are fabricated respectively based on the features of high density, high precision and array permutation of the CMOS/SEED optoelectronic integrated devices. The measuring results show that the center to center spacing between adjacent optical fibers in the same layer of the fiber array is 125 micrometer, and the spacing between …

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