Systems Architecture Commons^™

Keyboard - Smart Card Reader Controller Using Vhdl, Lani Mohd Zuwairi

Student Works (2000-2009)

As the time fly by the technology of computers has improves and much security is needed in every transaction of data that being done. In this project, designing a microcontroller for keyboard and smart card reader terminal integration is being done. At first stage, the architecture of the controller will analyze and studied. This will need some practice of knowledge in computer organization and architecture, as well as microprocessors architecture designs. Then the architecture is design using hardware prototyping. This is by using the VHSIC Hardware Description Language (VHDL). The codes done using the language then being simulate to get …

Design And Develop A Generic Cut-Through Switch, Nazaruddin Noraini

Student Works (2000-2009)

Today's advancement in network is related to the advancement of packet switching technology. Switching directs network traffic in an efficient manner – it sends information directly from the port of origin to only its destination port. Without switching, many networks are experiencing bandwidth shortages because of an increase in traffic due to the increased numbers of users, the amount of data transported between client/server applications, and the inefficient traffic patterns of some networks. Transmission of data from one destination to another is unguaranty successful. Sometimes the data will lost or conupted during transmission to destination port. To make data more …

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.

Two Approaches To Critical Path Scheduling For A Heterogeneous Environment, Guangxia Liu

Computer Science Theses & Dissertations

Advances in computing and networking technologies are making large scale distributed heterogeneous computing a reality. Multi-Disciplinary Optimization (MDO) is a class of applications that is being addressed under this paradigm. It consists of multiple heterogeneous modules interacting with each other to solve an overall design problem. An efficient implementation of such an application requires scheduling heterogeneous modules (with different computing and disk 1/0 requirements) on a heterogeneous set of resources (with different CPU, memory, disk IO specifications).

Given a set of tasks and a set of resources, an optimal schedule of the tasks on the resources is very hard to …

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.

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 …

Architectural Optimization Of Digital Libraries, Aileen O. Biser

Computer Science Theses & Dissertations

This work investigates performance and scaling issues relevant to large scale distributed digital libraries. Presently, performance and scaling studies focus on specific implementations of production or prototype digital libraries. Although useful information is gained to aid these designers and other researchers with insights to performance and scaling issues, the broader issues relevant to very large scale distributed libraries are not addressed. Specifically, no current studies look at the extreme or worst case possibilities in digital library implementations. A survey of digital library research issues is presented. Scaling and performance issues are mentioned frequently in the digital library literature but are …

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 …

Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Multimedia applications are sensitive to I/O latency and jitter when accessing data in secondary storage. Transparent adaptive prefetching (TAP) uses software feedback to provide multimedia applications with file system quality of service (QoS) guarantees. We are investigating how QoS requirements can be communicated and how they can be met by adaptive resource management. A preliminary test of adaptive prefetching is presented.

Adaptive Methods For Distributed Video Presentation, Crispin Cowan, Shanwei Cen, Jonathan Walpole, Carlton Pu

Computer Science Faculty Publications and Presentations

This paper describes problems and solutions for delivering real-time, multi-media presentations across the Internet. A key characteristic of presentations of continuous media datatypes, such as digital video and audio, is their need for predictable real-time data delivery. For example, an NTSC quality video presentation requires video frames to be displayed every 1/30th of a second. Variations in this display rate can be observable as stalls or glitches in the video stream and reduce the quality of the presentation [6]. Delivering such presentations across the Internet is difficult because highly variable band- width and latency make it difficult to predict the …

Defining Locally Shared Memory Constructs For Special Purpose Parallel Architectures, David J. Nielsen

Electrical & Computer Engineering Theses & Dissertations

Locally shared memory systems offer significant advantages over other parallel processing systems for specific classes of problems. Locally shared memory systems tend to be easier to program because explicit passing of messages is not necessary. The goal in defining a locally shared memory system is to allow only a small number of processors access to any single memory. If this goal is met, locally shared memory systems provide an architecture which is relatively simple to implement.

To make shared memory architectures attractive to designers of special purpose parallel architectures, the architectures must be scalable. To be scalable, the number of …

A Study Of Dynamic Optimization Techniques: Lessons And Directions In Kernel Design, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

The Synthesis kernel [21,22,23,27,28] showed that dynamic code generation, software feedback, and fine-grain modular kernel organization are useful implementation techniques for improving the performance of operating system kernels. In addition, and perhaps more importantly, we discovered that there are strong interactions between the techniques. Hence, a careful and systematic combination of the techniques can be very powerful even though each one by itself may have serious limitations. By identifying these interactions we illustrate the problems of applying each technique in isolation to existing kernels. We also highlight the important common under-pinnings of the Synthesis experience and present our ideas on …

Smimd - A Synchronous Multiple Instruction Multiple Data Computer Architecture, Cathy C. Roberts

Computer Science Theses & Dissertations

This thesis assesses the feasibility of utilizing a hypercube interconnect topology to link a heterogeneous processor array in a very long instruction word (VLIW) computer architecture. The research focused upon the selection of a suitable arrangement of processors for the computer and the subsequent demonstration of the architecture's capability to handle simple loop iterations. Previous attempts at VLIW computer design are summarized, the new SMIMD architecture is presented, and suggestions for future research are given. The thesis concludes with results of the initial performance evaluations of the architecture design.

Simulator For Concurrent Processing Data Flow Architectures, Mahyar R. Malekpour

Electrical & Computer Engineering Theses & Dissertations

A software simulator capable of simulating execution of an algorithm graph on a given system under the Algorithm To Architecture Mapping Model (ATAMM) rules is presented in this thesis. ATAMM is capable of modeling the execution of large-grained algorithms on distributed data flow architectures. Investigating the behavior and determining the performance of an ATAMM based system requires the aid of software tools. The ATAMM Simulator presented in this thesis is capable of determining the behavior, performance, and reliability of a system without having to build a hardware prototype. Case studies are performed on four algorithms to demonstrate the capabilities of …

Diagnostics Software For Concurrent Processing Computer Systems, Robert L. Jones Iii

Electrical & Computer Engineering Theses & Dissertations

Diagnostics software for analyzing ATAMM based concurrent processing systems is presented in this thesis. ATAMM (Algorithm to Architecture Mapping Model) is a new model developed by researchers at Old Dominion University and the NASA-Langley Research Center. ATAMM is capable of modeling the execution of large grain algorithms on distributed data flow architectures. Investigating a real or simulated ATAMM based system requires the aid of software tools. The software tool presented in this thesis can evaluate the behavior and performance of an ATAMM based system. The tool graphically portrays algorithm activities and processor activities. The tool's measurement capabilities indicate computing speed, …

Software Tools For Performance Evaluation Of Concurrent Processing, Rodrogo A. Obando

Electrical & Computer Engineering Theses & Dissertations

The development and use of software tools for performance evaluation of concurrent processing is presented in this thesis. The particular concurrent processing architecture proposed by Stoughton and Mielke is investigated. The modelling of this architecture is based on Petri net theory and it can be studied making use of circuit theory. Computation of lower bounds for Time Between Outputs (TBO) and Time Between Input and Output (TBIO) can be accomplished by using principles of circuit theory, among others. This new modelling needs to be deeply evaluated and studied. This evaluation and study is accomplished with the tools developed and presented …

Randomized Routing On Fat-Trees, Ronald I. Greenberg

Computer Science: Faculty Publications and Other Works

Fat-trees are a class of routing networks for hardware-efficient parallel computation. This paper presents a randomized algorithm for routing messages on a fat-tree. The quality of the algorithm is measured in terms of the load factor of a set of messages to be routed, which is a lower bound on the time required to deliver the messages. We show that if a set of messages has load factor lambda on a fat-tree with n processors, the number of delivery cycles (routing attempts) that the algorithm requires is O(lambda+lgnlglgn) with probability 1-O(1/ …

Analog Computer Simulation With Automatic Scaling By Digital Computer, Mark Anthony Motter

Electrical & Computer Engineering Theses & Dissertations

A computer-aided design approach for the simplification of analog computer simulation is presented. The simulation configuration consists of an EAI 2000 analog computer with serial communications link to a PDP — 11/24 digital computer. Under control of the PDP-11, the analog simulations are realized with appropriate time and magnitude scaling which adjusts the range of the simulation coefficients and prevents overloads of the analog components. The analog computer hardware configuration accommodates both stable plants up to eighth order and closed-loop systems up to tenth order. Cascade compensation is provided for the closed-loop systems.

The plant may be described by either …

Moment-Curvature-Thrust Relationships In Hybrid Members, Douglas Wrenn Fiala

Dissertations and Theses

In order to overcome the difficulties encountered in closed form solutions, moment-curvature-thrust relationships are developed for hybrid and nonhybrid cross sections utilizing an open form method. The use of horizontal sectors permits the inclusion of residual stresses and/or nonbilinear stress-strain relationships, if desired. Theoretical and experimental data are compared. Applications to circular tubes and other cross sections are discussed. Results indicate that open form solutions are feasible for calculating moment-curvature-thrust data. Hybrid cross sections are easily treated by open form solutions.