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2000

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Articles 271 - 282 of 282

Full-Text Articles in Electrical and Computer Engineering

Erbium-Ytterbium Codoped Fiber Amplifiers, Wai Yee Chan Jan 2000

Erbium-Ytterbium Codoped Fiber Amplifiers, Wai Yee Chan

Student Works (2000-2009)

The amplification characteristics of an Erbium/Ytterbium codoped fiber amplifier(EYDFA) pumped in both the 800nm and 980nm pump bands is reported. With -3m long Er-Yb fiber, the 813nm pumped-EYDFA shows small-signal gain exceeding 20dB over a 20nm bandwidth in the l.Sµm region where the peak gain of 38.4dB is achieved at 1535nm. A low noise figure of ~3.6d8 is also achieved at 1550nm. However, it is found that 980nm pumped­EYDF A suffers lower gain due to the effect of nonsaturable absorption by Yb³⁺ ions which causes high pump poWer loss, thus degrades the signal amplification in Er³⁺ system. Compared to the …

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Pendarab Titik Apungan 32bit Bertalian Paip, Noorzaily Mohamed Noor Jan 2000

Pendarab Titik Apungan 32bit Bertalian Paip, Noorzaily Mohamed Noor

Student Works (2000-2009)

Tesis ini menghuraikan sebuah pendarab titik apungan 32bit bertalian paip 18MHz yang direkabentuk menggunakan bahasa perihalan perkakasan YHDL, peralatan sintesis Synopsys FPGA Express dan ·peralatan pemetaan Xilinx Alliance, PTA ini menggunakan 1007 CLB dan 100 10B di mana peranti pemetaan yang digunakan ialah xc4036xl-bg432-2 daripada pustaka XC4000 Xilinx FPGA. Pendarab ini mengandungi tiga tahap talian paip yang belainan fungsi. Tahap pertama melaksanakan penjanaan dedarab dan penambahan dedarab secara carry save dan penambahan eksponen. la menggunakan algoritma Booth tertib kedua dan pepohon Wallace dengan pemampat 4-2. Tahap kcdua pula melakukan penambahan bawaan rambatan akhir, penormalan mantisa dan pembetulan eksponen manakala tahap …

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Mekanisma Pengujian Alu Menggunakan Teknik Boundary Scan, Abdul Aziz Ahmad Zaki Zamani Jan 2000

Mekanisma Pengujian Alu Menggunakan Teknik Boundary Scan, Abdul Aziz Ahmad Zaki Zamani

Student Works (2000-2009)

ALU testing mechanism using Boundary Scan technique is a project which is develop to be the tester for testing the digital circuit, integrated circuit and computer chip. The goal of this project is to develop a mechanism and as well building an ALU chip so that we will able to test and determine whether the chips are in a good shape and condition. This project contains two parts: one is lo develop an ALU and second is to develop the boundary scan chip. ALU is a unit or a component for a cligital circuit or a integrated circuit which is …

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Litar Aritmetik Reja, Abd. Mutalib Leorna Shazerine Jan 2000

Litar Aritmetik Reja, Abd. Mutalib Leorna Shazerine

Student Works (2000-2009)

Projek Ilmiah Tahap Akhir II, iaitu WXES 3182 adalah suatu latihan akademik di dalam penyelidikan, rekabentuk, pembangunan dan komunikasi yang melibatkan prinsip-prinsip sains komputer. Projek WXES 3182 ini merupakan kursus pelengkap bagi pelajar-pelajar tahun akhir untuk mendapatkan penganugerahan Sarjana Muda Sains Komputer. Projek WXES 3182 ini adalah kesinabungan daripada projek WXES 3181 Kajian penyehdikan yang telah dijalankan adalah berkaitan dengan konsep sistem nombor reja dan litar aritmetik reja. Laporan latihan ilmiah tahap akhir II ini, merangkumi pembangunan projek WXES 3181 dan WXES 3182. laporan ini terdiri daripada lapan bahagian dan diantaranya ialah pengenalan kepada projek, kajian literasi, metodologi yang digunakan …

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Vhdl Description For Ip Engine, Bathich Zeliall Jan 2000

Vhdl Description For Ip Engine, Bathich Zeliall

Student Works (2000-2009)

Developing hardware support for network layer protocol processing is a very complex and demanding task. However. for optimal performance hardware acceleration can be required. To cope with the situation. this project present a high-level design approach. which targets the development of configurable and reusable components. Therefore it obtains the integration of advanced tools for the development of the IP Engine into the design environment. This process is illustrated based on a TCP/IP header analysis and validation component for which initial performance results are presented. The development of this Engine is embedded in an approach to develop flexible and configurable protocol …

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New Buffer Layers, Large Band Gap Ternary Compounds: Cualte², K. Benchouk, E. Benseddik, C. O. El Moctar, J. C. Bernède, S. Marsillac, J. Pouzet, A Khellil Jan 2000

New Buffer Layers, Large Band Gap Ternary Compounds: Cualte², K. Benchouk, E. Benseddik, C. O. El Moctar, J. C. Bernède, S. Marsillac, J. Pouzet, A Khellil

Electrical & Computer Engineering Faculty Publications

After deposition, by evaporation under vacuum, of Al/Cu/Te, multilayer structures, annealing at 673 K or more for half an hour, under argon flow, allows CuAlTe2 films crystallized in the chalcopyrite structure to be obtained. The optical and electrical properties are interpreted by introducing the influence of impurity foreign phases present in the films. The optical properties are sensitive to the small Al2O3 domains randomly distributed into the CuAlTe2 polycrystalline matrix. The optical band gap is slightly increased (2.35 eV) by the presence of alumina. The conductivity measurements show that a short circuit effect can be induced by a binary Cu2-xTe …

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Integration Of Battery Energy Storage With Flexible Ac Transmission System Devices, Zhiping Yang Jan 2000

Integration Of Battery Energy Storage With Flexible Ac Transmission System Devices, Zhiping Yang

Doctoral Dissertations

"This dissertation, consisting of five papers, presents the results of research on the incorporation of battery energy storage into a Static Synchronous Compensator (StatCom). The main contribution of this body of work is the establishment of the modeling and control of the StatCom/BESS in power system dynamic applications. The first paper is focused on the steady state characteristics of the StatCom and StatCom/BESS. The characteristic curves of output voltage and output power were proposed and used in comparing the functionality of the StatCom and StatCom/BESS. In the second paper, a StatCom model was proposed and used in power flow analysis. …

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Design And Evaluation Of A Specialized Computer Architecture For Manipulating Binary Decision Diagrams, Robert K. Hatt Jan 2000

Design And Evaluation Of A Specialized Computer Architecture For Manipulating Binary Decision Diagrams, Robert K. Hatt

Dissertations and Theses

Binary Decision Diagrams (BDDs) are an extremely important data structure used in many logic design, synthesis and verification applications. Symbolic problem representations make BDDs a feasible data structure for use on many problems that have discrete representations. Efficient implementations of BOD algorithms on general purpose computers has made manipulating large binary decision diagrams possible. Much research has gone into making BOD algorithms more efficient on general purpose computers. Despite amazing increases in performance and capacity of such computers over the last decade, they may not be the best way to solve large, specialized problems. A computer architecture designed specifically to …

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Scene-Based Nonuniformity Correction With Video Sequences And Registration, Russell C. Hardie, Majeed M. Hayat, Earnest Armstrong, Brian Yasuda Jan 2000

Scene-Based Nonuniformity Correction With Video Sequences And Registration, Russell C. Hardie, Majeed M. Hayat, Earnest Armstrong, Brian Yasuda

Electrical and Computer Engineering Faculty Research and Publications

We describe a new, to our knowledge, scene-based nonuniformity correction algorithm for array detectors. The algorithm relies on the ability to register a sequence of observed frames in the presence of the fixed-pattern noise caused by pixel-to-pixel nonuniformity. In low-to-moderate levels of nonuniformity, sufficiently accurate registration may be possible with standard scene-based registration techniques. If the registration is accurate, and motion exists between the frames, then groups of independent detectors can be identified that observe the same irradiance (or true scene value). These detector outputs are averaged to generate estimates of the true scene values. With these scene estimates, and …

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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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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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Sar Imaging Using Fully Random Bandlimited Signals, Dmitriy S. Garmatyuk, Ram M. Narayanan Jan 2000

Sar Imaging Using Fully Random Bandlimited Signals, Dmitriy S. Garmatyuk, Ram M. Narayanan

Department of Electrical and Computer Engineering: Faculty Publications

A coherent ultrawideband (UWB) random noise synthetic aperture radar (SAR) has been developed and tested at the University of Nebraska. It has been experimentally shown that this type of radar is capable of extracting the phase and the amplitude of the backscattered signal, thus enabling us to create target profiles in the frequency domain. The use of fully random waveforms (bandlimited noise) as the transmit signal is analyzed in this paper. A UWB signal model is developed and radar signal processing is simulated to yield statistical characteristics of image formation using stochastic waveforms. The influence of UWB signal characteristics on …

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