Computer Engineering Commons^™

Turbo Codes For Wireless Mobile Communication Systems Applications, Moataz M. Salah

Theses and Dissertations

Research in coding theory has seen many proposals aimed at the construction of powerful codes using block and convolutional codes. Recently, a new forward error control code, known as turbo code, was introduced. This new code yields very good performance (near the Shannon limit) with relatively simple component codes and large interleavers in combination with an iterative decoding process. Among the most important applications of turbo codes are wireless mobile communication systems. A significant performance metric for this application is the minimization of end-to-end delay. In this dissertation, different ways to enhance the performance of turbo codes with short frames …

A New Approach For Computing The Bandwidth Statistics Of Avalanche Photodiodes, Majeed M. Hayat, Guoquan Dong

Electrical and Computer Engineering Faculty Research and Publications

A new approach for characterizing the avalanche-buildup-time-limited bandwidth of avalanche photodiodes (APDs) is introduced which relies on the direct knowledge of the statistics of the random response time. The random response time is the actual duration of the APD’s finite buildup-limited random impulse response function. A theory is developed characterizing the probability distribution function (PDF) of the random response time. Recurrence equations are derived and numerically solved to yield the PDF of the random response time. The PDF is then used to compute the mean and the standard deviation of the bandwidth. The dependence of the mean and the standard …

Swarm Engineering, S. Kazadi '90

Doctoral Dissertations

Swarm engineering is the natural evolution of the use of swarm-based techniques in the accomplishment of high level tasks using a number of simple robots. In this approach, one seeks not to generate a class of behaviors designed to accomplish a given global goal, as is the approach typically found in mainstream robotics. Once the class of behaviors has been understood and decided upon, specific behaviors designed to accomplish this goal may be generated that will complete the desired task without any concern about whether or not the final goal will actually be completed. As long as the generated behaviors …

Design And Fabrication Of Optical Resonators, Pushkar Moholkar

Theses

The design and fabrication of ring optical resonators for high-speed optical communication systems is the topic of this thesis. Its novelty is in two aspects: 1) Use of silicon wafers as an optical guiding medium; 2) Use of wafer bonding technique to attach two optical elements together.

The structure consists of two optical waveguides, the bus waveguide and the drop channel waveguide. A ring on top of these waveguides couples them in such a way that only one narrow spectral line is removed from the bus waveguides which propagates in the drop-channel waveguide. The assembly is fabricated using wafer-bonding technique …

Development Of A Demanufacturing System Modeling And Simulation Tool, Jingjing Hu

Theses

This thesis develops a demanufacturing system modeling and simulation tool as an interface between simulation methods and demanufacturers. This tool can mimic the behavior of demanufacturing facility and obtain penetrable understanding of the system. By this modeling tool, one can intuitively analyze the behavior of a system and improve the operational efficiency. Detailed designs on the simulation tool including user interface, logic, and user view are presented in this thesis. The initial prototype version of the system modeling and simulation tool has been completed with fourteen modules in the developed template. Each object in the template refers to a specific …

An Algorithm For Fast Route Lookup And Update, Pinar Altin Yilmaz

Theses

Increase in routing table sizes, number of updates, traffic, speed of links and migration to IPv6 have made IP address lookup, based on longest prefix matching, a major bottleneck for high performance routers. Several schemes are evaluated and compared based on complexity analysis and simulation results. A trie based scheme, called Linked List Cascade Addressable Trie (LLCAT) is presented. The strength of LLCAT comes from the fact that it is easy to be implemented in hardware, and also routing table update operations are performed incrementally requiring very few memory operations guaranteed for worst case to satisfy requirements of dynamic routing …

A Method Of Tracking Eye Motion For Human-Computer Interface, Martin Maranski

Theses

It would be of value to create another device for interfacing with a computer besides the commonly used handheld devices; one option is to determine where the user is looking on the screen. The major obstacle to overcome in this task is to be able to reliably track the motion of the iris and pupil in the eye. A method to do this is revealed here, using a variation of the Rough transform to detect circular patterns in a close shot of the eye. The algorithm was developed in Matlab and analyzed over a series of 20 sets of 6 …

Current-Voltage Characteristics Of Tasi2/Si And Mos Devices Using Labview, Prasant Tangirala

Theses

Analyses of current-voltage (LV) characteristics of Schottky Barrier Diodes (Tantalum Suicide) and Metal Oxide Semiconductor (MOS) Devices, using LabVIEW^TM, has been presented here. LabVIEW^TMTM, a graphical program development application, has been used to program a computer-driven Keithley Source Measure Unit (SMU) for device characterization. The SMU, which can be used as a Source Voltage - Measure Current as well as Source Current - Measure Voltage instrument, is used in the Source Voltage -Measure Current mode in this study. A General Purpose Interface Bus (GPIB) IEEE 488.2 has been used to interface the SMU with LabVIEW^{TM …}

Integrating Domain Knowledge With Data: From Crisp To Probabilistic And Fuzzy Knowledge, Hung T. Nguyen, Vladik Kreinovich, Leonid Reznik

Departmental Technical Reports (CS)

It is well known that prior knowledge about the domain can improve (often drastically) the accuracy of the estimates of the physical quantities in comparison with the estimates which are solely based on the measurement results. In this paper, we show how a known method of integrating crisp domain knowledge with data can be (naturally) extended to the case when the domain knowledge is described in statistical or fuzzy terms.

How Important Is Theory For Practical Problems? A Partial Explanation Of Hartmanis' Observation, Vladik Kreinovich, Luc Longpre

Departmental Technical Reports (CS)

No abstract provided.

Granularity As An Optimal Approach To Uncertainty - A General Mathematical Idea With Applications To Sleep, Consumption, Traffic Control, Learning, Etc., Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

Traditional statistical and fuzzy approaches to describing uncertainty are continuous in the sense that we use a (potentially infinite) set of values from the interval [0,1] to characterize possible degrees of uncertainty. In reality, experts describe their degree of belief by using one of the finitely many words from natural language; in this sense, the actual description of expert uncertainty is granular.

In this paper, we show that in some reasonable sense, granularity is the optimal way of describing uncertainty. A similar mathematical idea explains similar "granularity" in such diverse areas as sleep, consumption, traffic control, and learning.

A New Graph Characteristic And Its Application To Numerical Computability, Frank Harary, Vladik Kreinovich, Luc Longpre

Departmental Technical Reports (CS)

Many traditional numerical algorithms include a step on which we check whether a given real number a is equal to 0. This checking is easy for rational numbers, but for constructive real numbers, whether a number is 0 or not is an algorithmically undecidable problem. It is therefore desirable to re-formulate the existing algorithms with as few such comparisons as possible. We describe a new graph characteristic; this characteristic describes how the number of comparisons in an algorithm can be reduced.

A Comment On The Shape Of The Solution Set For Systems Of Interval Linear Equations With Dependent Coefficients, Goetz Alefeld, Vladik Kreinovich, Guenter Mayer, Michael Huth

Departmental Technical Reports (CS)

This article is a short supplement to our previously published paper, in which we prove that each semialgebraic set can be represented as a projection of a solution set of some system of linear equations with dependent coefficients. The new results says that interval occurring can be chosen as narrow as wanted. This new result is proven by a simple linear transformation.

Computational Complexity Of Planning Based On Partial Information About The System's Present And Past States, Chitta Baral, Le Chi Tuan, Raul A. Trejo, Vladik Kreinovich

Departmental Technical Reports (CS)

Planning is a very important AI problem, and it is also a very time-consuming AI problem. To get an idea of how complex different planning problems are, it is useful to describe the computational complexity of different general planning problems. This complexity has been described for problems in which planning is based on the (complete or partial) information about the current state of the system. In real-life planning, in addition to this information, we often also use the knowledge about the system's past behavior. To describe such more realistic planning situations, a special language L was developed in 1997 by …

Fuzzy (Granular) Levels Of Quality, With Applications To Data Mining And To Structural Integrity Of Aerospace Structures, Roberto A. Osegueda, Carlos Ferregut, Vladik Kreinovich, Seelam Seetharami, Harry Schulte

Departmental Technical Reports (CS)

Experts usually describe quality by using words from natural language such as "perfect", "good", etc. In this paper, we deduce natural numerical values corresponding to these words, and show that these values explain empirical dependencies uncovered in data mining and in the analysis of structural integrity of aerospace structures.

Why Two Sigma? A Theoretical Justification, Hung T. Nguyen, Vladik Kreinovich, Gennady N. Solopchencko, Ching-Wang Tao

Departmental Technical Reports (CS)

For a normal distribution, the probability density is everywhere positive, so in principle, all real numbers are possible. In reality, the probability that a random variable is far away from the mean is so small that this possibility can be often safely ignored. Usually, a small real number k is picked (e.g., 2 or 3); then, with a probability P0(k)~1 (depending on k), the normally distributed random variable with mean a and standard deviation sigma belongs to the interval A=[a-k*sigma,a+k*sigma].

The actual error distribution may be non-Gaussian; hence, the probability P(k) that a random variable belongs to A differs from …

The Use Of Fuzzy Measures In Pain Relief Control, Vladik Kreinovich, Nadipuram R. Prasad

Departmental Technical Reports (CS)

Many people suffer from a continuous strong pain which is caused solely by the malfunction of the pain mechanism itself. One way to ease their pain is to electrically stimulate the spinal cord. Since the equations of pain are not known, we must use heuristic methods to find the optimal pain relief stimulation. In this paper, we show how fuzzy measures and similar nonlinear models can be used in pain relief control: they can be used to determine the parameters of the model which describes the dependence of the pain relief on the applied stimulation. Thus, fuzzy measures lead to …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 5, May 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A nineteen page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Rotation-Invariant Synthetic Discriminant Function Filter For Pattern Recognition, Vahid R. Riasati, Partha P. Banerjee, Mustafa A. G. Abushagur, Kenneth B. Howell

Electrical and Computer Engineering Faculty Publications

The ring synthetic discriminant function (RSDF) filter for rotation-invariant response is discussed for pattern recognition. This method uses one half of a slice of the Fourier transform of the object to generate the transfer function of the filter. This is accomplished by rotating the one half of a slice in the Fourier domain through 2π rad about the zero-frequency point of the Fourier plane. This filter has the advantage of always matching at least one half of a slice of the Fourier transform of any rotation of the image. An analytical discussion of the filter construction and correlation results are …

A Proposed Inconsistency Management Model For An Integrated Multiple View Oo-Software Development Environment, Mahmoud Gouda Mohamed

Archived Theses and Dissertations

No abstract provided.

3d Outside Cell Interference Factor For An Air-Ground Cdma ‘Cellular’ System, David W. Matolak

Faculty Publications

We compute the outside-cell interference factor of a code-division multiple-access (CDMA) system for a three-dimensional (3-D) air-to-ground (AG) "cellular-like" network consisting of a set of uniformly distributed ground base stations and airborne mobile users. The CDMA capacity is roughly inversely proportional to the outside-cell interference factor. It is shown that for the nearly free-space propagation environment of these systems, the outside-cell interference factor can be larger than that for terrestrial propagation models (as expected) and depends approximately logarithmically upon both the cell height and cell radius.

Building The Veco Online Community : A Model For Encouraging Novices., Michelle Williams, Janine Bowes.

Australian Journal of Teacher Education

Building online networks and designing network activity is becoming central to how educators and other education-based professionals work, train others and teach students. It is only since 1995 that Internet connectivity in Australia has provided the critical mass and momentum which alters how people work, who they work with and how they learn. Thus the business of helping professional networks develop and become part of the lives of their members is uncharted territory and an area for research and development for educators in all fields. This paper shares the story of the development of an Australian Network for Vocational Education …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 16, Number 4, April 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Towards Feasible Approach To Plan Checking Under Probabilistic Uncertainty: Interval Methods, Raul A. Trejo, Vladik Kreinovich, Chitta Baral

Departmental Technical Reports (CS)

The main problem of planning is to find a sequence of actions that an agent must perform to achieve a given objective. An important part of planning is checking whether a given plan achieves the desired objective. Historically, in AI, the planning and plan checking problems were mainly formulated and solved in a deterministic environment, when the initial state is known precisely and when the results of each action in each state is known (and uniquely determined). In this deterministic case, planning is difficult, but plan checking is straightforward. In many real-life situations, we only know the probabilities of different …

Towards Optimal Mosaicking Of Multi-Spectral Images, Francisco Garcia, Roberto Araiza, Brain Rzycki

Departmental Technical Reports (CS)

To cover a certain area, it is often necessary to combine several satellite photos. To get a proper combination, we need to appropriately position and orient these photos relative to one another, i.e., mosaic these photos. With the new generation of multi-spectral satellites, for each area, we have several hundred images which correspond to different wavelengths. At present, when we mosaic two images, we only use one of the wavelengths and ignore the information from the other wavelengths. It is reasonable to decrease the mosaicking error by using images corresponding to all possible wavelengths in mosaicking. In this paper, we …

Data Generation In The Nigerian Environment: The Cbn Experience., A. A. Sere-Ejembi

Bullion

The paper examines data collection activities of the statistical services division in collaboration with its Lagos liaison office as well as the zonal research units. The paper analyzes the survey methods applied by them. The task of easing data collection should be regarded as a continuous process. This is relevant even to the most developed economies with sophisticated technology for data collection and processing. Finally, with an improvement in the literacy level and overall appreciation of the role of reliable statistics in the country, it is believed that the public would embrace data generation and availability of relevant statistics will …

Process Flow Optimization Studies Through Discrete Event Simulation, Milind Chokshi

Electrical & Computer Engineering Theses & Dissertations

Computer-aided simulation has begun to emerge as a powerful tool for numerical analysis of the behavior and anticipated performance of industrial systems and their optimization. Applications include materials handling, storage and controls systems, prediction of manufacturing efficiencies, and production optimization. Simulations are used to test baseline models and subsequently analyze new production concepts, operating strategies, and planned procedures prior to costly implementation.

The study of process flows in a manufacturing environment is difficult due to its inherent stochastic nature. Breakdown of the sub-systems and failures of machines is a random process and needs to be solved based on concepts of …

A Generic Object-Oriented Server Model, Brian Douglas Jones

Electrical & Computer Engineering Theses & Dissertations

The purpose of this paper is to introduce a generic, object-oriented model for the simulation of networks of queues. Generic simulation modeling provides robust ways of laying out processes in stochastic, event driven simulations. The approach taken is to define a methodology that will be implementation independent, termed the Generic Server Simulation Model (GSSM); thus, leaving the implementers to choose the best (most suited for their use) means of implementation. GSSM uses many object-oriented concepts to provide its basic structure and has in its design the ability to take advantage of these object-oriented concepts, including reuse of (existing) code. GSSM …

A Digital Pressure Sensor Data Acquisition System In A Wind Tunnel Model, John J. Novakoski

Electrical & Computer Engineering Theses & Dissertations

Pressure measurements on wind tunnel models provide an important aid to overall aerodynamic analysis and design of aircraft and vehicles. Most pressure measurements in wind tunnels are made using analog pressure sensors with interfacing electronics that connect to an external data acquisition unit. Some of desirable features of an improved pressure measurement system are that it be: 1) model embeddable, 2) inherently digital in nature, 3) intelligent, and 4) controllable by a remote computer.

An intelligent, model-embedded, eight-channel digital pressure sensor system has been developed and tested in a wind tunnel. The implemented system consists of Micro-Electro-Mechanical System (MEMS) digital …

Fundamental Properties Of Pair-Wise Interactions Naturally Lead To Quarks And Quark Confinement: A Theorem Motivated By Neural Universal Approximation Results, Vladik Kreinovich

Departmental Technical Reports (CS)

In traditional mechanics, most interactions are pair-wise; if we omit one of the particles from our description, then the original pair-wise interaction can sometimes only be represented as interaction between triples, etc. It turns out that, vice versa, every possible interaction between N particles can be represented as pair-wise interaction if we represent each of the original N particles as a triple of new ones (and two new ones are not enough for this representation). The resulting three "particles" actually represent a single directly observable particles and in this sense, cannot be separated. So, this representation gives a fundamental reason …