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Portland State University

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1999

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Articles 1 - 18 of 18

Full-Text Articles in Engineering

Work In Progress: Automating Proportion/Period Scheduling, David Steere, Jonathan Walpole, Calton Pu Dec 1999

Work In Progress: Automating Proportion/Period Scheduling, David Steere, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

The recent effort to define middleware capable of supporting real-time applications creates the opportunity to raise the level of abstraction presented to the programmer. We propose that proportion/period is a better abstraction for specifying resource needs and allocation than priorities. We are currently investigating techniques to address some issues that are restricting use of proportion/period scheduling to research real-time prototypes. In particular, we are investigating techniques to automate the task of selecting proportion and period, and that allow proportion/period to incorporate job importance under overload conditions.


Investigation Of Image Feature Extraction By A Genetic Algorithm, Steven P. Brumby, James P. Theiler, Simon J. Perkins, Neal R. Harvey, John J. Szymanski, Jeffrey J. Bloch, Melanie Mitchell Nov 1999

Investigation Of Image Feature Extraction By A Genetic Algorithm, Steven P. Brumby, James P. Theiler, Simon J. Perkins, Neal R. Harvey, John J. Szymanski, Jeffrey J. Bloch, Melanie Mitchell

Computer Science Faculty Publications and Presentations

We describe the implementation and performance of a genetic algorithm which generates image feature extraction algorithms for remote sensing applications. We describe our basis set of primitive image operators and present our chromosomal representation of a complete algorithm. Our initial application has been geospatial feature extraction using publicly available multi-spectral aerial-photography data sets. We present the preliminary results of our analysis of the efficiency of the classic genetic operations of crossover and mutation for our application, and discuss our choice of evolutionary control parameters. We exhibit some of our evolved algorithms, and discuss possible avenues for future progress.


Capillary Surfaces In An Exotic Container: Results From Space Experiments, Paul Concus, Robert Finn, Mark M. Weislogel Sep 1999

Capillary Surfaces In An Exotic Container: Results From Space Experiments, Paul Concus, Robert Finn, Mark M. Weislogel

Mechanical and Materials Engineering Faculty Publications and Presentations

Experimental results from the Interface Configuration Experiment (ICE) performed aboard the Space Shuttle and the Mir Space Station are reported. The experiment concerns fluid interfaces in certain ‘exotic’ containers in a low-gravity environment. These containers are rotationally symmetric and have the property that for given contact angle and liquid volume, a continuum of distinct rotationally symmetric equilibrium configurations can appear, all of which have the same mechanical energy. These symmetric equilibrium configurations are unstable, in that deformations that are not rotationally symmetric can be shown mathematically to yield configurations with lower energy. It is found experimentally, in confirmation of mathematical …


Fine-Grain Period Adaptation In Soft Real-Time Environments, David Steere, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole Sep 1999

Fine-Grain Period Adaptation In Soft Real-Time Environments, David Steere, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Reservation-based scheduling delivers a proportion of the CPU to jobs over a period of time. In this paper we argue that automatically determining and assigning this period is both possible and useful in general purpose soft real-time environments such as personal computers and information appliances. The goal of period adaptation is to select the period over which a job is guaranteed to receive its portion of the CPU dynamically and automatically. The choice of period represents a trade-off between the amount of jitter observed by the job and the overall efficiency of the system. Secondary effects of period include quantization …


Qos Scalability For Streamed Media Delivery, Charles Krasic, Jonathan Walpole Sep 1999

Qos Scalability For Streamed Media Delivery, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Applications with real-rate progress requirements, such as mediastreaming systems, are difficult to deploy in shared heterogenous environments such as the Internet. On the Internet, mediastreaming systems must be capable of trading off resource requirements against the quality of the media streams they deliver, in order to match wide-ranging dynamic variations in bandwidth between servers and clients. Since quality requirements tend to be user- and task-specific, mechanisms for capturing quality of service requirements and mapping them to appropriate resource-level adaptation policies are required. In this paper, we describe a general approach for automatically mapping user-level quality of service specifications onto resource …


Double-Pass High-Gain Laser Amplifiers, Janet M. Casperson, Frederick G. Moore, Lee W. Casperson Sep 1999

Double-Pass High-Gain Laser Amplifiers, Janet M. Casperson, Frederick G. Moore, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Double-pass laser amplifiers have advantages of compactness and efficiency in the amplification of optical signals, and such amplifiers have been employed in a wide range of optical systems. Work in this area is reviewed briefly, and analytical solutions are obtained for the intensity of the electromagnetic waves in double-pass homogeneously-broadened high-gain laser amplifiers. Expressions are derived relating the output power to the input, including the effects of arbitrary mirror reflectivity and frequency detuning from line center. In the limits of weak saturation and of high reflectivity the results are consistent with earlier studies.


Constructive Induction Machines For Data Mining, Marek Perkowski, Stanislaw Grygiel, Qihong Chen, Dave Mattson Mar 1999

Constructive Induction Machines For Data Mining, Marek Perkowski, Stanislaw Grygiel, Qihong Chen, Dave Mattson

Electrical and Computer Engineering Faculty Publications and Presentations

"Learning Hardware" approach involves creating a computational network based on feedback from the environment (for instance, positive and negative examples from the trainer), and realizing this network in an array of Field Programmable Gate Arrays (FPGAs). Computational networks can be built based on incremental supervised learning (Neural Net training) or global construction (Decision Tree design). Here we advocate the approach to Learning Hardware based on Constructive Induction methods of Machine Learning (ML) using multivalued functions. This is contrasted with the Evolvable Hardware (EHW) approach in which learning/evolution is based on the genetic algorithm only.


Grazing Reflection Of Gaussian Beams, Lee W. Casperson Jan 1999

Grazing Reflection Of Gaussian Beams, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The reflectivities of most surfaces are higher for grazing or near-90-deg angles of incidence than for more perpendicular or near-zero-deg angles. Grazing-incidence configurations are especially important in the development of lasers and optical systems that operate in the far-ultraviolet and soft-x-ray regions of the spectrum, where transparent or highly reflecting media are almost unknown. Analytical solutions of the paraxial wave equation are obtained for the grazing reflection and complex interference effects that take place when a Gaussian beam interacts at shallow angles with a reflecting surface.


Constructive Induction Machines For Data Mining, Marek Perkowski, Stanislaw Grygiel, Qihong Chen, Dave Mattson Jan 1999

Constructive Induction Machines For Data Mining, Marek Perkowski, Stanislaw Grygiel, Qihong Chen, Dave Mattson

Electrical and Computer Engineering Faculty Publications and Presentations

"Learning Hardware" approach involves creating a computational network based on feedback from the environment (for instance, positive and negative examples from the trainer), and realizing this network in an array of Field Programmable Gate Arrays (FPGAs). Computational networks can be built based on incremental supervised learning (Neural Net training) or global construction (Decision Tree design). Here we advocate the approach to Learning Hardware based on Constructive Induction methods of Machine Learning (ML) using multivalued functions. This is contrasted with the Evolvable Hardware (EHW) approach in which learning/evolution is based on the genetic algorithm only. Various approaches to supervised inductive learning …


Improvements In Modeling Dissolved Oxygen In Activated Sludge Systems, Jacek Makinia, Scott A. Wells Jan 1999

Improvements In Modeling Dissolved Oxygen In Activated Sludge Systems, Jacek Makinia, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The aim of this research was to show the impact of the flow conditions and variations in the aeration intensity on changes in the predicted dissolved oxygen (DO) concentrations in a full-scale activated sludge reactor. The Activated Sludge Model No. 1 was used to describe the biochemical processes. The studies were performed at the Rock Creek wastewater treatment plant in Hillsboro, OR (USA). The simulation results were compared with data originating from two 24-hour experiments. The model that best reflected the spatial and diurnal distributions of the DO concentrations was the one-dimensional advection-dispersion equation with a variable overall oxygen mass …


A New Technique For Estimating Confidence Intervals On Dea Efficiency Estimates, Janice Forrester, Timothy R. Anderson Jan 1999

A New Technique For Estimating Confidence Intervals On Dea Efficiency Estimates, Janice Forrester, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

A new approach to chance constrained DEA is described and experimental results are given for calculating a confidence band for the estimated production function. This allows an interval containing the most likely production function, to be specified with a predetermined level of confidence.


Using Data Envelopment Analysis For Evaluating Alternative Software Development Process Configurations, Timothy R. Anderson, Peter K. Ghavami Jan 1999

Using Data Envelopment Analysis For Evaluating Alternative Software Development Process Configurations, Timothy R. Anderson, Peter K. Ghavami

Engineering and Technology Management Faculty Publications and Presentations

Summary form only given as follows. The goal of achieving better software depends on improvements in software development processes. This paper provides a nonparametric, quantitative methodology for evaluating alternative software development process configurations as a tool for process improvement. The methodology uses data envelopment analysis (DEA) for comparing the impact of varying degrees of software inspection on project schedule, cost and quality. Since every phase of the development process can be inspected at varying levels, a large number of process combinations become possible. Thus a manager's job to compare and select an efficient process configuration can become tedious. This is …


A Comparison Of Efficiency Measurement Using Data Envelopment Analysis And Regression In The Utility Industry, Janice Forrester, Timothy R. Anderson Jan 1999

A Comparison Of Efficiency Measurement Using Data Envelopment Analysis And Regression In The Utility Industry, Janice Forrester, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

It is the intent of this paper to discuss the theoretical differences between the manner in which regression and data envelopment analysis (DEA) separate variation into that which is caused by noise and that caused by inefficiency. It examines the empirical results of independent studies, one that used regression and one that used DEA. The studies were performed one year apart by independent teams using the same data and responding to the same questions. Both studies focus on monitoring the efficiency of the electric utility providers in light of deregulation


Head Movement And Vision In Underwater-Feeding Birds Of Stream, Lake, And Seashore, Lee W. Casperson Jan 1999

Head Movement And Vision In Underwater-Feeding Birds Of Stream, Lake, And Seashore, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Studies head movement and vision in underwater-feeding birds. Review of relevant literature on the physiological and behavioral aspects of vision; Role of vertical head movement as an aid in the acquisition of visual information.


Logic Synthesis For A Regular Layout, Marek Perkowski, Yang Xu, Malgorzata Chrzanowska-Jeske Jan 1999

Logic Synthesis For A Regular Layout, Marek Perkowski, Yang Xu, Malgorzata Chrzanowska-Jeske

Electrical and Computer Engineering Faculty Publications and Presentations

New algorithms for generating a regular two-dimensional layout representation for multi-output, incompletely specified Boolean functions, called, Pseudo-Symmetric Binary Decision Diagrams (PSBDDs), are presented. The regular structure of the function representation allows accurate prediction of post-layout areas and delays before the layout is physically generated. It simplifies power estimation on the gate level and allows for more accurate power optimization. The theoretical background of the new diagrams, which are based on ideas from contact networks, and the form of decision diagrams for symmetric functions is discussed. PSBDDs are especially well suited for deep sub-micron technologies where the delay of interconnections limits …


Trace: A Visual Software System To Explore Properties Of Reed-Muller Movement Functions, Marek Perkowski, Alan Mishchenko Jan 1999

Trace: A Visual Software System To Explore Properties Of Reed-Muller Movement Functions, Marek Perkowski, Alan Mishchenko

Electrical and Computer Engineering Faculty Publications and Presentations

We present new experimental Windows 95/98/NT software for investigation of graph properties of boolean (in particular, Reed-Muller) logic with an equal number n of inputs and outputs (called movement functions). Realized at the input of an n-bit register, such functions create autonomous Finite State Machines (FSMs). TRACE software system allows the user to visualize State Transition Graphs (STGs) of the autonomous FSMs. Other features of TRACE help explore graph properties of function families. These families are produced by a generic function, differing from it only in the order of components, one operation, or one literal (this literal is complemented or …


Adaptive Resource Management Via Modular Feedback Control, Ashvin Goel, David Steere, Calton Pu, Jonathan Walpole Jan 1999

Adaptive Resource Management Via Modular Feedback Control, Ashvin Goel, David Steere, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

A key feature of tomorrow’s operating systems and runtime environments is their ability to adapt. Current state of the art uses an ad-hoc approach to building adaptive software, resulting in systems that can be complex, unpredictable and brittle. We advocate a modular and methodical approach for building adaptive system software based on feedback control. The use of feedback allows a system to automatically adapt to dynamically varying environments and loads, and allows the system designer to utilize the substantial body of knowledge in other engineering disciplines for building adaptive systems. We have developed a toolkit called SWiFT that embodies this …


Feedback Based Dynamic Proportion Allocation For Disk I/O, Dan Revel, Dylan Mcnamee, Calton Pu, David Steere, Jonathan Walpole Jan 1999

Feedback Based Dynamic Proportion Allocation For Disk I/O, Dan Revel, Dylan Mcnamee, Calton Pu, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we propose to use feedback control to automatically allocate disk bandwidth in order to match the rate of disk I/O to the real-rate needs of applications. We describe a model for adaptive resource management based on measuring the relative progress of stages in a producer-consumer pipeline. We show how to use prefetching to transform a passive disk into an active data producer whose progress can be controlled via feedback. Our progress-based framework allows the integrated control of multiple resources. The resulting system automatically adapts to varying application rates as well as to varying device latencies.