Engineering Commons^™

Enhancements To The Scalable Coherent Interface Cache Protocol, Robert J. Safranek

Dissertations and Theses

As the number of NUMA system's cache coherency protocols based on the IEEE Std. 1596-1992, Standard for Scalable Coherent Interface (SCI) Specification increases, it is important to review this complex protocol to determine if the protocol can be enhanced in any way. This research provides two realizable extensions to the standard SCI cache protocol. Both of these extensions lie in the basic confines of the SCI architectures.

The first extension is a simplification to the SCI protocol in the area of prepending to a sharing list. Depending if the cache line is marked "Fresh" or "Gone", the flow of events …

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.

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

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.

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 …

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

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

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

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 …

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 …

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 …

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.

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.

A Feedback-Driven Proportion Allocator For Real-Rate Scheduling, David Steere, Ashvin Goel, Joshua Gruenberg, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we propose changing the decades-old practice of allocating CPU to threads based on priority to a scheme based on proportion and period. Our scheme allocates to each thread a percentage of CPU cycles over a period of time, and uses a feedback-based adaptive scheduler to assign automatically both proportion and period. Applications with known requirements, such as isochronous software devices, can bypass the adaptive scheduler by specifying their desired proportion and/or period. As a result, our scheme provides reservations to applications that need them, and the benefits of proportion and period to those that do not. Adaptive …

An Efficient And Effective Approach To Column-Based Input/Output Encoding In Functional Decomposition, Michael Burns, Marek Perkowski, Stanislaw Grygiel, Lech Jozwiak

Electrical and Computer Engineering Faculty Publications and Presentations

Encoding in Curtis-style decompositions is the process of assigning codes to groups of compatible columns (or cubes) so that the binary logic descriptions of the predecessor and successor sub-functions can be created for further decomposition. In doing so, the sub-functions created are functionally equivalent to the set of care values specified in the original function. In this paper an input/output encoding algorithm DC_ENC is presented that is designed to achieve the simplest total complexity of the predecessor and successor sub-functions, and to increase the total number of don't cares for their further utilization in subsequent decomposition steps of these sub-functions.

Production And Propagation Of Hermite–Sinusoidal-Gaussian Laser Beams, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

Hermite–sinusoidal-Gaussian solutions to the wave equation have recently been obtained. In the limit of large Hermite–Gaussian beam size, the sinusoidal factors are dominant and reduce to the conventional modes of a rectangular waveguide. In the opposite limit the beams reduce to the familiar Hermite–Gaussian form. The propagation of these beams is examined in detail, and resonators are designed that will produce them. As an example, a special resonator is designed to produce hyperbolic-sine-Gaussian beams. This ring resonator contains a hyperbolic-cosine-Gaussian apodized aperture. The beam mode has finite energy and is perturbation stable.

Static Compaction Of Test Sequences For Synchronous Sequential Circuits, Lijie Qi

Dissertations and Theses

Today, VLSI design has progressed to a stage where it needs to incorporate methods of testing circuits. The Automatic Test Pattern Generation (ATPG) is a very attractive method and feasible on almost any combinational and sequential circuit.

Currently available automatic test pattern generators (ATPGs) generate test sets that may be excessively long. Because a cost of testing depends on the test length, compaction techniques have been used to reduce that length. The motivation for studying test compaction is twofold. Firstly, by reducing the test sequence length, the memory requirements during the test application and the test application time are reduced. …

Synthetic Files: Enabling Low-Latency File I/O For Qos-Adaptive Applications, Dylan Mcnamee, Dan Revel, Calton Pu, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Files are a tried and true operating system abstraction. They present a simple byte-stream model of I/O that has proven intuitive for application programmers and efficient for operating system builders. However, current file systems do not provide good support for adaptive continuous media (CM) applications - an increasingly important class of applications that exhibit complex access patterns and are particularly sensitive to variations in I/O performance. To address these problems we propose synthetic files. Synthetic files are specialized views of underlying regular files, and convert complex file access patterns into simple sequential synthetic file access patterns. Synthetic file construction can …

Photographic Studies Of Laser-Induced Bubble Formation In Absorbing Liquids And On Submerged Targets: Implications For Drug Delivery With Microsecond Laser Pulses, Hanqun Shangguan, Lee W. Casperson, Dennis L. Paisley, Scott A. Prahl

Electrical and Computer Engineering Faculty Publications and Presentations

Pulsed laser ablation of blood clots in a fluid-filled blood vessel is accompanied by an explosive evaporation process. The resulting vapor bubble rapidly expands and collapses to disrupt the thrombus (blood clot). The hydrodynamic pressures following the bubble expansion and collapse can also be used as a driving force to deliver clot-dissolving agents into thrombus for enhancement of laser thrombolysis. Thus, the laser-induced bubble formation plays an important role in the thrombus removal process. We investigate the effects of boundary configurations and materials on bubble formation with time-resolved flash photography and high-speed photography. Potential applications in drug delivery using microsecond …

Quality Of Service Semantics For Multimedia Database Systems, Jonathan Walpole, Charles Krasic, Ling Liu, David Maier, Calton Pu, Dylan Mcnamee, David Steere

Computer Science Faculty Publications and Presentations

Quality of service (QoS) support has been a hot research topic in multimedia databases, and multimedia systems in general, for the past several years. However, there remains little consensus on how QoS support should be provided. At the resource-management level, systems designers are still debating the suitability of reservation- based versus adaptive QoS management. The design of higher system layers is less clearly understood, and the specification of QoS requirements in domain-specific terms is still an open research topic. To address these issues, we propose a QoS model for multimedia databases. The model covers the specification of user-level QoS preferences …

Location Independent Names For Nomadic Computers, David Steere, Mark Morrissey, Peter Geib, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Recent advances in the Domain Name System (DNS) and the Dynamic Host Configuration Protocol (DHCP) have enabled a new approach to supporting mobile users: location independent naming. In this approach, machines use the same hostname from any internet location, but use an IP address that corresponds to their current location. We describe a protocol that implements location independent naming for nomadic computers, i.e., machines that do not need transparent mobility. Our protocol allows hosts to move across security domains, uses existing protocols, and preserves existing trust relationships. Therefore, it preserves the performance and security of normal IP for nomadic computers …

Adaptation Space: Surviving Non-Maskable Failures, Crispin Cowan, Lois Delcambre, Anne-Francoise Le Meur, Ling Liu, David Maier, Dylan Mcnamee, Michael Miller, Calton Pu, Perry Wagle, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Some failures cannot be masked by redundancies, because an unanticipated situation occurred, because fault-tolerance measures were not adequate, or because there was a security breach (which is not amenable to replication). Applications that wish to continue to offer some service despite nonmaskable failure must adapt to the loss of resources. When numerous combinations of non-maskable failure modes are considered, the set of possible adaptations becomes complex. This paper presents adaptation spaces, a formalism for navigating among combinations of adaptations. An adaptation space describes a collection of possible adaptations of a software component or system, and provides a uniform way of …

The Columbia River Plume Study: Subtidal Variability In The Velocity And Salinity Fields, B. M. Hickey, Leonard J. Pietrafesa, David A. Jay, William C. Boicourt

Civil and Environmental Engineering Faculty Publications and Presentations

A comprehensive study of the strongly wind driven midlatitude buoyant plume from the Columbia River, located on the U.S. west coast, demonstrates that the plume has two basic structures during the fall/winter season, namely, a thin (~5~15 m), strongly stratified plume tending west to northwestward during periods of southward or light northward wind stress and a thicker (~10~40 m), weakly stratified plume tending northward and hugging the coast during periods of stronger northward stress. The plume and its velocity field respond nearly instantaneously to changes in wind speed or direction, and the wind fluctuations have timescales of 2-10 days. Frictional …

Hermite–Sinusoidal-Gaussian Beams In Complex Optical Systems, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

Sinusoidal-Gaussian beams have recently been obtained as exact solutions of the paraxial wave equation for propagation in complex optical systems. Another useful set of beam solutions for Cartesian coordinate systems is based on Hermite–Gaussian functions. A generalization of these solution sets is developed here. The new solutions are referred to as Hermite–sinusoidal-Gaussian beams, because they are in the form of a product of Hermite-polynomial functions of either complex or real argument, sinusoidal functions of complex argument, and Gaussian functions of complex argument. These beams are valid for propagation through systems that can be represented in terms of complex beam matrices, …

Tooth Contact Sensing Apparatus And Method, John D. Summer, Edmund Pierzchala, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

An apparatus and method for sensing tooth contact includes at least one, and more typically plural, vibration sensors which are coupled to the non-biting surfaces of teeth. These sensors produce output signals when the associated teeth contact one another during jaw closing, the output signals being processed to provide information concerning tooth contact. For example, information concerning the ?rst tooth which contacts may be determined, the sequence of contact by various teeth may be determined, as well as the time between contact of the various teeth. Other information concerning tooth contact may also be determined and dis played in a …

Field Solutions For Bidirectional High-Gain Laser Amplifiers And Oscillators, Lee W. Casperson, Mohammad Azadeh

Electrical and Computer Engineering Faculty Publications and Presentations

General analytical solutions are obtained for the amplitude, phase, and intensity of the electromagnetic waves in bidirectional homogeneously broadened high-gain laser amplifiers and oscillators. These solutions are important as increasingly high-gain lasers are being employed in practical systems. Expressions are derived relating the output power to the input, including the effects of arbitrary mirror reflectivities and frequency detunings from the line center. For negligible reflectivities, these regenerative amplifier results reduce to earlier expressions for single-pass high-gain amplifiers. Multivalued outputs also occur, and in the limit of low gain per pass the results are consistent with earlier studies of single-frequency laser …

Stackguard: Automatic Adaptive Detection And Prevention Of Buffer-Overflow Attacks, Crispin Cowan, Calton Pu, David Maier, Heather Hinton, Jonathan Walpole, Peat Bakke, Steve Beattie, Aaron Grier, Perry Wagle, Qian Zhang

Computer Science Faculty Publications and Presentations

This paper presents a systematic solution to the persistent problem of buffer overflow attacks. Buffer overflow attacks gained notoriety in 1988 as part of the Morris Worm incident on the Internet. While it is fairly simple to fix individual buffer overflow vulnerabilities, buffer overflow attacks continue to this day. Hundreds of attacks have been discovered, and while most of the obvious vulnerabilities have now been patched, more sophisticated buffer overflow attacks continue to emerge.

We describe StackGuard: a simple compiler technique that virtually eliminates buffer overflow vulnerabilities with only modest performance penalties. Privileged programs that are recompiled with the StackGuard …

Passive Circuit Modeling Using Ipa510, Hassan Hiwaidi Al-Sheikhly

Dissertations and Theses

Characterizing the high speed interconnect performance of circuit board, integrated circuit packages and multichip module become very important when the clock frequencies in digital and RF systems become larger than 200 MHz. At time scales less than 2 ns distributed approach must be used to measure package parasitics (stray inductance and capacitance) and transmission line effects.

A practical way to measure and model the package parasitics is by utilizing Interconnect Parameter Analyzer (IP A510). The IP A510 uses Time Domain Reflectometry (TDR) technique. The TDR technique is based on sending a waveform to a device under test (DUT) and capturing …

An Approach To Exact Modeling Of The Pwm Switch, Anas N. Al-Rabadi

Dissertations and Theses

Large number of small-signal models of de-to-de power converters exists already. These models usually use two techniques. The first is the averaging technique, such as: volt-second and current-second balance, state space averaging, and the averaged modeling approach. The other technique focuses on the exact modeling approach, such as: the application of time varying systems theory to linearize networks. One of the methodologies to apply the above techniques, is to view the three-terminal systems as a two-port network.

The aim of the work presented in this thesis is to develop a new approach, by the application of the two-port network methodology …

Communicating Conceptual Design Of Mechatronic Systems, Muir Lee Harding

Dissertations and Theses

Today's engineering designers must adapt to a changing model of product development. In the past, a single engineer could design, develop and deploy competitive systems --this is often no longer the case. Designing a mechanical system with integrated microprocessor control requires the collaboration of a cross-disciplinary team of engineers and, in many cases, no single member of the team understands the workings of the entire system. Consequently, as systems become increasingly complex, the ability to collaborate and reliably communicate design information becomes more and more crucial. Effective communication 1s particularly critical in conceptual design, where a poor decision has the …