Engineering Commons^™

Gaussian Beams In Hollow Metal Waveguides: Experiment, Marius Ghita, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Gaussian beams have been widely used for propagating electromagnetic waves in free space and in certain other optical systems. It has been suggested that recurring forms of such beams might also be useful for propagation in planar or rectangular metal waveguides. Experimental verification of the recurrence of the Gaussian field distribution in metal waveguides is reported here.

Implicit Algorithms For Multi-Valued Input Support Manipulation, Alan Mishchenko, Craig Files, Marek Perkowski, Bernd Steinbach, Christina Dorotska

Electrical and Computer Engineering Faculty Publications and Presentations

We present an implicit approach to solve problems arising in decomposition of incompletely specified multi-valued functions and relations. We introduce a new representation based on binaryencoded multi-valued decision diagrams (BEMDDs). This representation shares desirable properties of MDDs, in particular, compactness, and is applicable to weakly-specified relations with a large number of output values. This makes our decomposition approach particularly useful for data mining and machine learning. Using BEMDDs to represent multi-valued relations we have developed two complementary input support minimization algorithms. The first algorithm is efficient when the resulting support contains almost all initial variables; the second is efficient when …

Fast Heuristic Minimization Of Exclusive-Sums-Of-Products, Alan Mishchenko, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Exclusive-Sums-Of-Products (ESOPs) play an important role in logic synthesis and design-for-test. This paper presents an improved version of the heuristic ESOP minimization procedure proposed in [1,2]. The improvements concern three aspects of the procedure: (1) computation of the starting ESOP cover; (2) increase of the search space for solutions by applying a larger set of cube transformations; (3) development of specialized datastructures for robust manipulation of ESOP covers. Comparison of the new heuristic ESOP minimizer EXORCISM-4 with other minimizers (EXMIN2 [3], MINT [4], EXORCISM-2 [1] and EXORCISM3 [2]) show that, in most cases, EXORCISM-4 produces results of comparable or better …

A General Decomposition For Reversible Logic, Marek Perkowski, Lech Jozwiak, Pawel Kerntopf, Alan Mishchenko, Anas Al-Rabadi, Alan Coppola, Andrzej Buller, Xiaoyu Song, Svetlana Yanushkevich, Vlad P. Shmerko, Malgorzata Chrzanowska-Jeske, Mozammel Huq Azad Khan

Electrical and Computer Engineering Faculty Publications and Presentations

Logic synthesis for reversible logic differs considerably from standard logic synthesis. The gates are multi-output and the unutilized outputs from these gates are called “garbage”. One of the synthesis tasks is to reduce the number of garbage signals. Previous approaches to reversible logic synthesis minimized either only the garbage or (predominantly) the number of gates. Here we present for the first time a method that minimizes concurrently the number of gates, their total delay and the total garbage. Our method adopts for reversible logic many ideas developed previously for standard logic synthesis (such as Ashenhurst/Curtis Decomposition, Dietmeyer’s Composition, non-linear preprocessing …

Bi-Decomposition Of Multi-Valued Relations, Alan Mishchenko, Marek Perkowski, Bernd Steinbach

Electrical and Computer Engineering Faculty Publications and Presentations

This presentation discusses an approach to decomposition of multivalued functions and relations into networks of two-input gates implementing multi-valued MIN and MAX operations. The algorithm exploits both the incompleteness of the initial specification and the flexibilities generated in the process of decomposition. Experimental results over a set of multi-valued benchmarks show that this approach outperforms other approaches in the quality of final results and CPU time.

Decomposition Of Relations: A New Approach To Constructive Induction In Machine Learning And Data Mining -- An Overview, Marek Perkowski, Stanislaw Grygiel

Electrical and Computer Engineering Faculty Publications and Presentations

This is a review paper that presents work done at Portland State University and associated groups in years 1989 - 2001 in the area of functional decomposition of multivalued functions and relations, as well as some applications of these methods.

Estimating Scanning Characteristics From Corners In Bilevel Images, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

Degradations that occur during scanning can cause errors in Optical Character Recognition (OCR). Scans made in bilevel mode (no grey scale) from high contrast source patterns are the input to the estimation processes. Two scanner system parameters are estimated from bilevel scans using models of the scanning process and bilevel source patterns. The scanner's point spread function (PSF) width and the binarization threshold are estimated by using corner features in the scanned images.

These estimation algorithms were tested in simulation and with scanned test patterns. The resulting estimates are close in value to what is expected based on grey-level analysis. …

Rules For A Cellular Automaton To Model Quantum-Dot Cellular Automata, Teresa Cole, John C. Lusth

Electrical and Computer Engineering Faculty Publications and Presentations

Quantum-dot cellular automata are one of several new device architectures whose operation is based on local interactions, much like cellular automata. We have implemented several rule sets for a cellular automaton that could be used to model the behavior of quantum-dot cellular automata and used them to test most of the wire and gate configurations proposed for these devices. Arrangements of cells for which any particular cell has neighbors which are not adjacent to each other generally behave as expected. Unfavorable arrangements of cells such as those with bends and crosses tend to either have incorrect outputs or be unstable …

Scanner Parameter Estimation Using Bilevel Scans Of Star Charts, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

Scanning a high contrast image in bilevel mode results in image degradation. This is caused by two primary effects: blurring and thresholding. This paper expands on a method of estimating a joint distortion parameter, called the edge spread, from a star sector test chart in order to calculate the values of the point spread function width and binarization threshold. This theory is also described for variations in the source pattern which can represent degradations caused by repetition of the bilevel process as would be seen in printing then scanning, or in repeated photocopying. Estimation results are shown for the basic …

Regularity And Symmetry As A Base For Efficient Realization Of Reversible Logic Circuits, Marek Perkowski, Pawel Kerntopf, Andrzej Buller, Malgorzata Chrzanowska-Jeske, Alan Mishchenko, Xiaoyu Song, Anas Al-Rabadi, Lech Jozwiak, Alan Coppola

Electrical and Computer Engineering Faculty Publications and Presentations

We introduce a Reversible Programmable Gate Array (RPGA) based on regular structure to realize binary functions in reversible logic. This structure, called a 2 * 2 Net Structure, allows for more efficient realization of symmetric functions than the methods shown by previous authors. In addition, it realizes many non-symmetric functions even without variable repetition. Our synthesis method to RPGAs allows to realize arbitrary symmetric function in a completely regular structure of reversible gates with smaller “garbage” than the previously presented papers. Because every Boolean function is symmetrizable by repeating input variables, our method is applicable to arbitrary multi-input, multi-output Boolean …

Processing Algorithms For Tracking Speckle Shifts In Optical Elastography Of Biological Tissues, Donald D. Duncan, Sean J. Kirkpatrick

Electrical and Computer Engineering Faculty Publications and Presentations

Parametric and nonparametric data processing schemes for analyzing translating laser speckle data used to investigate the mechanical behavior of biological tissues are examined. Crosscorrelation, minimum mean square estimator, maximum likelihood, and maximum entropy approaches are discussed and compared on speckle data derived from cortical bone samples undergoing dynamic loading. While it was not the purpose of this paper to demonstrate that one processing technique is superior to another, maximum likelihood and maximum entropy approaches are shown to be particularly useful when the observed speckle motion is small.

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

Electrical and Computer Engineering Faculty Publications and Presentations

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 …

An Efficient Indirect Branch Predictor, Yul Chu, M. R. Ito

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, we present a new hybrid branch predictor called the GoStay2, which can effectively reduce indirect misprediction rates. The GoStay2 has two different mechanisms compared to other 2- stage hybrid predictors that use a Branch Target Buffer (BTB) as the first stage predictor: Firstly, to reduce conflict misses in the first stage, a new effective 2-way cache scheme is used instead of a 4-way setassociative. Secondly, to reduce mispredictions caused by an inefficient predict and update rule, a new selection mechanism and update rule are proposed. We have developed a simulation program by using Shade and Spixtools, provided …