Digital Commons Network^™

Development Of Object-Oriented Components For Atm Network Simulation With Emphasis On Congestion Control, Wai Kit Sin

Student Works (2000-2009)

Asynchronous Transfer Mode (ATM) is a very high-speed transmission technology. The barrage of technological advancements has continuously enhanced the network performance. There is an increasing dependence on the network. Thus, there is a need to accurately predict the impact of network and applications changes in the dynamic network environment. The network simulator is a tool to analyze the behavior of ATM networks without the expense of building a real network. The simulation of this simulator will give the results that imitate the real network environment. The aim of this project is to develop object-oriented components for an ATM Network Simulator …

Accurate Parameter Estimation For An Articulatory Speech Synthesizer With An Improved Neural Network Mapping, Hali̇s Altun, Tankut Yalçinöz, K. Mervyn Curtis

Turkish Journal of Electrical Engineering and Computer Sciences

Neural network (NN) applications have recently been employed to extract the parameters of an articulatory speech synthesizer from a given speech signal. Results from these attempts showed that a single NN is insufficient to cover all of the possible configurations uniquely. Moreover, apart from their computational advantages, NN mapping is so far not superior to the other mapping techniques [1]. Thus there is a clear need to improve NN solution to the inverse problem. Results from our earlier experiments with an articulatory speech synthesizer have shown that the statistical characteristic of the articulatory target pattern vectors can be exploited for …

Dynamic Bandwidth Allocation Using Neural-Fuzzy In Atm Network, Yan Sing Chua

Student Works (2000-2009)

Dynamic bandwidth allocation is becoming one of the crucial issues in the design and research in the computer network. This is due to the continuous increasing demand of intensive applications that require more bandwidth while retaining higher quality. Dynamic bandwidth allocation utilises the current network state information to optimise the bandwidth distribution. The state information can be gathered through prediction using past data and measurement on current state. Agility and flexibility of dynamic bandwidth allocation using Neural-Fuzzy has the advantage that it can adapt to the state changes of the network. ATM network carries heterogeneous traffic and this causes the …

Breakdown Voltage In Thin Iii-V Avalanche Photodiodes, Mohammad A. Saleh

Electrical and Computer Engineering Faculty Research and Publications

1. The dead-space multiplication theory of Hayat et al. [Journal of Lightwave Technology 10, 1415 (1992)], in conjunction with the multiplication-width-independent ionization-coefficient model developed by Saleh et al. [IEEE Trans. Electron Devices 47, 625 (2000)], are shown to accurately predict breakdown voltages for thin avalanche photodiodes of GaAs, InP, In_0:52Al_0:48As, and Al_0:2Ga_0:8As, over a broad range of device widths. The breakdown voltage is determined from the analytical expression for the impulse-response-function decay rate.

A Wideband Monopole For Reconfigurable Multiband Radio Terminals, Max Ammann

Conference papers

A wideband planar monopole employing two broadbanding techniques is investigated, and is shown to yield an impedance bandwidth ratio of 10:1 or greater for a return loss of 8 dB. The radiation pattern bandwidth is also investigated

Sharing Health-Care Records Over The Internet, Jane Grimson, Gaye Stephens, Benjamin Jung, William Grimson, Damon Berry, Sebastien Pardon

Articles

Presents a novel approach to sharing electronic health-care records that leverages the Internet and the World Wide Web, developed as part of two European Commission-funded projects, Synapses and SynEx. The approach provides an integrated view of patient data from heterogeneous, distributed information systems and presents it to users electronically. Synapses and SynEx illustrate a generic approach in applying Internet technologies for viewing shared records, integrated with existing health computing environments. Prototypes have been validated in a variety of clinical domains and health-care settings

Adaptive Notch Filter For Single And Multiple Narrow-Band Interference, Selina Kuek Lin Mei

Theses : Honours

In this project, the adaptive notch filter for single and Multiple narrow-band interference is implemented using simplified LMS algorithm. Performances of the LMS adaptive algorithms is evaluated and analysed through simulation on the computer using Matlab. The algorithm are then written in C programme and implemented using Texas Instrument Tool which consist of TMS320C54x EMV board and Code Composer Studio.

Video Compression Using Wavelets And Hierarchical Motion Estimation, Andrew Peter Byrne

Theses : Honours

This thesis investigates the benefits and the significant compression that can be obtained from data that has been decomposed using a wavelet transform. A video compression algorithm was developed that employs the wavelet transform and a hierarchical motion estimation algorithm which itself utilises benefits of the wavelet transform. Using MATLAB, a popular software tool for matrix based computation and analysis, several functions were developed which together formed the video compression algorithm. A variety of tests were conducted on a sample video sequence to ascertain the strengths and weaknesses of the techniques employed. The results, although not the same as the …

Indoor Radio Channel Of Bluetooth Technology, Kai Hock Charlie Khoo

Theses : Honours

This thesis discusses the findings of the final year project involving the characterisation of indoor radio channel specified by Bluetooth technology through theoretical analysis, simulations and actual measurements through field experiments. The concepts of indoor radio propagation effects and its statistical models arc explored. In addition, Bluetooth specifications are also studied and presented in Section 1. These provided a clear understanding of the radio propagation behaviour inside a building and the radio performance of Bluetooth specifications. Profound understanding of the propagation characteristics of the indoor radio channel is a major requirement for successful design of any indoor wireless communication systems. …

A Cable/Wireless Modulation/Demodulation Frontend Module For High Speed/Broadband Datalink, Pay Peng Clarice Chong

Theses : Honours

What are the modulation/demodulation schemes that are suitable tor cable or wireless high speed or broadband data link, between 1 Mbps to 30 Mbps? The recent adoption of modulation schemes such as OFDM, 8-VSB, OAM, for Digital Television broadcast (DTV), Asymmetrical Digital Subscriber Lines (ADSL), and Cable Modem (CM) for Internet access, is poss'1ble because of the increase bit/Hz in these modulations over conventional modulation schemes. These modulation/demodulation schemes could also offer similar advantages to dedicated data link applications such as home-networking using cable or wireless medium. This report document the project implementation of Quadrature Amplitude Modulation as the modulation …

An Efficient Instruction Cache Scheme For Object-Oriented Languages, Yul Chu, M. R. Ito

Electrical and Computer Engineering Faculty Publications

We present an efficient cache scheme, which can considerably reduce instruction cache misses caused by procedure call/returns. This scheme employs N-way banks and XOR mapping functions. The main function of this scheme is to place a group of instructions separated by a call instruction into a bank according to the initial and final bank selection mechanisms. After the initial bank selection mechanism selects a bank on an instruction cache miss, the final bank selection mechanism will determine the final bank for updating a cache line as a correction mechanism. These two mechanisms can guarantee that recent groups of instructions exist …

Ensemble Monte Carlo Based Simulation Analysis Of Gan Hemts For High-Power Microwave Device Applications, Tao Li

Electrical & Computer Engineering Theses & Dissertations

The high electron mobility transistors (HEMTs) fabricated using wide-bandgap semiconductors show promise as high-gain, low-noise devices with superior frequency response. The structure and operation principle of HEMT are first briefly discussed. The distinguishing and unique properties of GaN are reviewed and compared with those of GaAs. Calculations of the electronic mobility and drift velocity have been carried out for bulk GaN based on a Monte Carlo approach, which serves as a validity check for the simulation model.

By taking account of polarization effects, degeneracy and interface roughness scattering, important microwave performance measures such as the dynamic range, harmonic distortion and …

A Committee Of Neural Networks For Automatic Speaker Recognition (Asr) Systems, Viresh Moonasar, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes how the results of speaker verification systems can be improved and made robust with the use of a committee of neural networks for pattern recognition rather than the conventional single-network decision system. It illustrates the use of a supervised learning vector quantization neural network as the pattern classifier. Linear predictive coding and cepstral signal processing techniques are utilized to form hybrid feature parameter vectors to combat the effect of decreased recognition success with increased group size (number of speakers to be recognized)

Volume Management In San Environment, Chang-Soo Kim, Gyoung-Bae Kim, Bum-Joo Shin

Electrical and Computer Engineering Faculty Research & Creative Works

Logical volume managers have long been key components of a storage system. Their key features are creation of logical or virtual views of physical storage devices and support for various software RAID levels. These make it possible to overcome the limits to capacity, availability and performance of a physical storage device. Most logical volume managers are operated in a single system environment. They are not adequate for SAN (storage area network) environments where several hosts share and access a logical volume at the same time. Some recent logical volume managers are run in a multi-host environment. However, they cannot support …

Measurement And Monitoring Of Microwave Reflection And Transmission Properties Of Cement-Based Specimens, Sergey Kharkovsky, M. F. Akay, U. C. Hasar, C. D. Atis

Electrical and Computer Engineering Faculty Research & Creative Works

The results of measurement and monitoring of reflection and transmission properties of cement-based specimens (blocks of mortar, concrete) during long time of their service lives, including hydration process, and different curing conditions at microwave frequencies (X-band) are presented. A simple and inexpensive measurement system that utilizes the nondestructive and contactless free space method is used. Dependencies of the reflection and transmission coefficients on water-to-cement ratio, preparing and curing conditions of the specimens are demonstrated. It is shown that the reflection coefficient is approximately stable after hydration process while the transmission coefficient changes during long time of the specimen''s service life. …

Measurement And Monitoring Of Microwave Reflection And Transmission Properties Of Cement-Based Materials For Propagation Modeling, Sergey Kharkovsky, U. C. Hasar, M. F. Akay, C. D. Atis

Electrical and Computer Engineering Faculty Research & Creative Works

A non-destructive, contactless, free-space method is used for measuring and monitoring the properties of cement-based materials. We analyse the propagation factor, penetration depth and reflection and transmission coefficients of the plane wave interacting with the highly lossy specimen. Results are presented of the measurement and monitoring of the properties of cement-based materials during all stages of their lives and different curing conditions The expected applications of the results for propagation modelling are discussed.

Experiments On Adaptive Techniques For Host-Based Intrusion Detection, Timothy Draelos, Michael Collins, David Duggan, Edward Thomas, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

This research explores four experiments of adaptive host-based intrusion detection (ID) techniques in an attempt to develop systems that can detect novel exploits. The technique considered to have the most potential is adaptive critic designs (ACDs) because of their utilization of reinforcement learning, which allows learning exploits that are difficult to pinpoint in sensor data. Preliminary results of ID using an ACD, an Elman recurrent neural network, and a statistical anomaly detection technique demonstrate an ability to learn to distinguish between clean and exploit data. We used the Solaris Basic Security Module (BSM) as a data source and performed considerable …

Factory Automation: A Controls Course For Every University, Kelvin T. Erickson

Electrical and Computer Engineering Faculty Research & Creative Works

The majority of new control engineering positions is now in manufacturing and involves programmable logic controllers (PLCs). The paper describes two courses developed at the University of Missouri-Rolla to satisfy this demand. Both courses present the subject of programming PLCs with an emphasis on the design of the programs. Both courses contain an integral laboratory component that solidifies the concepts presented in the lectures. The philosophy and pedagogical features of the two courses are first described, followed by the structure of the lecture and the laboratory exercises.

Organizational Change, Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

The Electrostatic Interaction Of Charged, Dust-Particle Pairs In Plasmas, M. E. Markes, P. F. Williams

Department of Electrical and Computer Engineering: Faculty Publications

We report the results of a study of the electrostatic interaction between negatively charged particles in a plasma. The goal of the study was to investigate the possibility of an attractive interaction which would make possible the formation of “molecules” of particles. For all approximations relating the positive ion density to the local electrostatic potential that we examined, we find that the interaction is repulsive for all particle separations.

A Technique For Analyzing Radiation From Conformal Antennas Mounted On Arbitrarily-Shaped Conducting Bodies, Dean Arakaki, Douglas H. Werner, Raj Mittra

Electrical Engineering

This paper presents an efficient method to solve the problem of radiation from conformal aperture and microstrip antennas mounted on arbitrarily-shaped conducting bodies. The method, based on the surface equivalence and reciprocity principles, uses a combination of the Finite Difference Time Domain (FDTD) and Method of Moments (MoM) techniques to substantially improve the computational efficiency of the radiation pattern calculation. When the geometry and location of the radiating element are modified, only a small portion of the overall analysis requires re-simulation. This leads to a significant improvement in computational efficiency over presently used techniques, and can substantially improve design efficiency …

System Level Microwave Design: Radar-Based Laboratory Projects, Michael A. Jensen, David V. Arnold, Donald E. Crockett

Faculty Publications

Two laboratory projects-a Doppler radar and a synthetic aperture radar (SAR)-designed to augment traditional electromagnetics education are proposed. The projects introduce students to component and system level design and expose them to modern computer-aided design (CAD) tools, microstrip and surface mount fabrication technologies, and industry standard test equipment and procedures. Additionally, because the projects result in a working radar system, students gain new enthusiasm for the electromagnetics discipline and directly see its relevance in the engineering field. Implementation of these laboratories within the curriculum have proven to be highly motivational and educational and have even contributed to increased enrolments in …

Enabling Mobile Agents Communication, Mohammad Samarah, Philip K. Chan

Electrical Engineering and Computer Science Faculty Publications

In this paper, we investigate the need for well-suited remote communication architectures to address communication issues in mobile agent environments. We study the implication of mobility for agent architectures – specifically, ways in which the architecture may facilitate agent communication. We present an architecture for inter-agent communication suitable for remote messaging, agent monitoring, agent tracing, and agent debugging for mobile agent environments. The architecture allows for the dynamic adaptation of communication components. It provides for a seamless and continuous active communication during the agent migration process. We have implemented an agent framework simulator that conforms to all these requirements. The …

A Protocol Language Approach To Generating Client-Server Software, Philip K. Chan, Melvin A.L. Douglas

Electrical Engineering and Computer Science Faculty Publications

Client-server software is becoming more common as the Internet grows. To ease the burden of repeatedly writing low-level communication and protocol code, we seek to design a protocol language, My Simple Protocol Language (MSPL), that produces the corresponding communication functions. The programmer then supplies the rest of the application-specific code but never modifies the generated code. Besides saving development time, this approach also reduces programming errors. The potential to develop more efficient code also exists once the technique of generating code is mastered. The main contribution, however, is that unlike RPC, Corba or RMI, we provide the user with not …

Laboratories Teaching Concepts In Microcontrollers And Hardware-Software Co-Design, Daryl G. Beetner, Hardy J. Pottinger, Kyle Mitchell

Electrical and Computer Engineering Faculty Research & Creative Works

Hardware software co-design is becoming increasingly important to the embedded systems industry. It will soon be fundamental to digital systems design. As such, students in electrical and computer engineering and in computer science should be introduced to hardware-software co-design early in their undergraduate education.

We are designing laboratory modules which introduce concepts of hardware-software co-design in an undergraduate's first course on microcontrollers and digital systems design. Students use design automation tools to develop FPGA-based hardware for use with an 8051-microcontroller and use common software development tools to develop microcontroller software in C or assembly language. Co-simulation of hardware and software …

Self-Organization In Porous 6h–Sic, S. Zangooie, John A. Woollam, H. Arwin

Department of Electrical and Computer Engineering: Faculty Publications

Pores in porous 6H–SiC were found to propagate first nearly parallel with the basal plane and gradually change direction and align with the c axis. As a consequence, well-defined columnar pores were formed. It was shown that the rate of change of propagation directions was influenced by the etching parameters, such as hydrofluoric acid concentration and current density. Larger currents resulted in formation of larger pores. Pore sizes were found to increase with depth due to a decrease of the acid concentration. In addition, due to chemical etching effects, larger pore sizes were obtained close to the sample surface.

Performance Monitoring In Umr's Solar Car, Louis Mccarthy, Josh Pieper, Aaron Rues, Cheng-Hsiao Wu

Electrical and Computer Engineering Faculty Research & Creative Works

We describe the instrumentation in UMR's solar car. Accurate knowledge of the operating parameters inside the solar car is shown to be crucial to maintaining high efficiency and reliability. The power trackers keep the solar array operating at its highest efficiency by conditioning the input and maintaining the maximum power point of the solar cells.

Reduction Of Peak To Average Power Ratio In Ofdm And Ofdm-Cdma System, Jie Cheng

Theses

High Peak to Average Power Ratio is a main problem in Orthogonal Frequency Division Multiplexing(OFDM) system and Orthogonal Frequency Division Multiplexing -Code Division Multiple Access (OFDM-CDMA) system. Considering a compensated High Power Amplifier(HPA), in order to keep linearity for amplification, Input Back-Off(IBO) of the HP-A, has to be increased for handling a high PAPR. Higher 1130 will make HPA less efficient. Additionally, a signal with high PAPR will suffer clipping when PAPR is larger than 1130 of the HPA. Clipping can cause the distortion of the signal and deteriorate the performance of the system. Reduction of PAPR is a main …

Phase Tunability In A Conductor Backed Coplanar Waveguide Patch Antenna, Idan Mandelbaum

Theses

Traditionally beam steering in phase array antenna systems is achieved using tunable phase shifters or switched feed networks. Here, a tunable patch antenna element is suggested as a novel alternative to a combination of a radiating element and a phase shifter. A conductor backed coplanar waveguide patch antenna is chosen due to its suitability to mounted external tuning elements, using varactor diodes. Limited types of lumped tuning circuits, using varactor diodes, have been tested, though a lumped as well as distributed tuning is feasible in the chosen antenna configuration. Approximate analytical models for coplanar waveguide patch antennas with finite ground …

Method Of Testing And Diagnosing Field Programmable Gate Arrays, Miron Abramovici, Eric Seng-Kar Lee, Charles Eugene Stroud

Electrical and Computer Engineering Faculty Patents

A method of testing field programmable gate arrays (FPGAs) includes establishing a first group of programmable logic blocks as test pattern generators or output response analyzers and a second group of programmable logic blocks as blocks under test. This is followed by generating test patterns and comparing outputs of two blocks under test with one output response analyzer. Next is the combining of results of a plurality of output response analyzers utilizing an iterative comparator in order to produce a pass/fail indication. The method also includes the step of reconfiguring each block under test so that each block under test …