Digital Commons Network^™

The Expected Lifetime Of “Single-Address-Space” Operating Systems, David Kotz, Preston Crow

Dartmouth Scholarship

Trends toward shared-memory programming paradigms, large (64-bit) address spaces, and memory-mapped files have led some to propose the use of a single virtual-address space, shared by all processes and processors. Typical proposals require the single address space to contain all process-private data, shared data, and stored files. To simplify management of an address space where stale pointers make it difficult to re-use addresses, some have claimed that a 64-bit address space is sufficiently large that there is no need to ever re-use addresses. Unfortunately, there has been no data to either support or refute these claims, or to aid in …

A User-Level Process Package For Concurrent Computing, Ravi Konuru, Steve Otto, Jonathan Walpole, Robert Prouty, Jeremy Casas

Computer Science Faculty Publications and Presentations

A lightweight user-level process(ULP) package for parallel computing is described. Each ULP has its own register context, stack, data and heap space and communication with other ULPs is performed using locally synchronous, location transparent, message passing primitives. The aim of the package is to provide support for lightweight over-decomposition, optimized local communication and transparent dynamic migration. The package supports a subset of the Parallel Virtual Machine(PVM) interface[Sun90).

Managing Memory For Real-Time Queries, Hwee Hwa Pang, Michael J. Carey, Miron Livny

Research Collection School Of Computing and Information Systems

The demanding performance objectives that real-time database systems (RTDBS) face necessitate the use of priority resource scheduling. This paper introduces a Priority Memory Management (PMM) algorithm that is designed to schedule queries in RTDBS. PMM attempts to minimize the number of missed deadlines by adapting both its multiprogramming level and its memory allocation strategy to the characteristics of the offered workload. A series of simulation experiments confirms that PMM's admission control and memory allocation mechanisms are very effective for real-time query scheduling.

The Analysis Of Iterative Elliptic Pde Solvers Based On The Cubic Hermite Collocation Discretization, Yu-Ling Lai, Apostolos Hadjidimos, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Communication Operations On Coarse-Grained Mesh Architectures, Susanne E. Hambrusch, Farooq Hameed, Ashfaq A. Khokhar

Department of Computer Science Technical Reports

No abstract provided.

Polynomial Surface Patch Representations, Chandrajit L. Bajaj

Department of Computer Science Technical Reports

No abstract provided.

Building Information Systems For Mobile Environments, Evaggelia Pitoura, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

An Open Structure For Pde Solving Systems, Elias N. Houstis, John R. Rice, Sanjiva Weerawarana

Department of Computer Science Technical Reports

No abstract provided.

The Roles Of Models, Software Tools, And Applications In High Performance Computing, Leah H. Jamieson, Susanne E. Hambrusch, Ashfaq A. Khokhar, Edward J. Delp

Department of Computer Science Technical Reports

No abstract provided.

A Software Platform For Integrating Symbolic Computation With A Pde Solving Environment, Sanjiva Weerawarana, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Load Balancing The Heat Equation In A Heterogeneous Environment With Pvm, N. Nemer-Preece, L. Mullin

Computer Science Technical Reports

Parallel processing is maturing with the ability to program heterogeneous environments and the help of networking systems such as PVM. Heterogeneous multiprocessing has been revolutionized due to tools such as PVM which allows the user to develop code independent of the machine arthitecture. This thesis develops a load balancing algorithm to handle the time march problem, heat conduction. It is based on the speeds of the machines in the current environment.

The heat equation algorithm is enhanced by the Psi Calculus of a Mathematics of Arrays. \l' Calculus allows the indexing of the heat matrix in terms of starts, stops …

Providing Assurance For Reponsive Computing Systems, G. Tsai, B. Mcmillin

Computer Science Technical Reports

A responsive computing system is a hybrid of real-time, distributed and fault-tolerant systems. In such a system, severe consequences will occur if the logical and physical specifications of the system are not met. In this dissertation, an approach to ensure satisfaction of specifications in the operational environment is presented as follows. First, we specify properties of the system using ITL formulas. Next, we collect, at runtime, events and maintain equivalent event histories to represent system execution. Finally, we apply a decision procedure to determine satisfaction of the formulas. A run-time evaluation system was built according to this approach and we …

Skin Cancer Diagnosis Using Hierarchal Neural Networks And Fuzzy Logic, H. C. Lee, F. Ercal

Computer Science Technical Reports

Skin cancer, the most common cancer in the United States that affects about 600,000 Americans every year, accounts for 1% of all cancer deaths. Among all, Malignant Melanoma is the most virulent form of skin cancer that is responsible for 75% of all deaths from skin cancer. In 1992, approximately 32,000 people are expected to develop melanoma and about 6,700 will die. However, even malignant melanoma can be treated successfully if detected in the early phase. Therefore, our research goal is to diagnose skin cancer, especially malignant melanoma.

In this study, only the digitized images obtained from color tumor slides …

Classification Characteristics Of Som And Art2, J. Aleshunas, D. St. Clair, W. Bond

Computer Science Technical Reports

Artificial neural network algorithms were originally designed to model human neural activities. They attempt to recreate the processes involved in such activities as learning, short term memory, and long term memory. Two widely used artificial neural network algorithms are the Self-Organizing Map (SOM) and the Adaptive Resonance Theory (ART2). Each was designed to simulate a particular biological neural activity. Both can be used as unsupervised data classifiers.

This paper compares performance characteristics of two unsupervised artificial neural network architectures; the SOM and the ART2 networks. The primary factors analyzed were classification accuracy, sensitivity to data noise, and sensitivity to the …

The Myriad Federated Database Prototype, San-Yih Hwang, Ee Peng Lim, H. R. Yang, S. Musukula, K. Mediratta, M. Ganesh, D. Clements, J. Stenoien, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

Myriad is a federated database system (FDBS) prototype being developed at the University of Minnesota. The main objective behind this prototyping effort is to provide "enterprise-wide" information by integrating independently developed databases while preserving the local autonomy of the component DBMSs and applications. In Myriad, multiple federations can be formed. A federation consists of an integrated database whose schema is represented as a set of integrated relations derived from the export relations provided by the component DBMSS. SQL, mainly due to its simplicity and popularity among database users and vendors, has been adopted to express global queries as well as …

Multirate Time-Frequency Distributions, John R. O'Hair

Theses and Dissertations

Multirate systems, which find application in the design and analysis of filter banks, are demonstrated to also be useful as a computational paradigm. It is shown that any problem which can be expressed a set of vector-vector, matrix-vector or matrix-matrix operations can be recast using multirate. This means all of numerical linear algebra can be recast using multirate as the underlying computational paradigm. As a non-trivial example, the multirate computational paradigm is applied to the problem of Generalized Discrete Time- Frequency Distributions GDTFD to create a new family of fast algorithms. The first of this new class of distributions is …

Designing A New Programming Methodology For Optimizing Array Accesses In Complex Scientific Problems, Larry Coffin

Opportunities for Undergraduate Research Experience Program (OURE)

Many problems of interest to scientists and engineers, such as fluid flow and stress analysis, require the solution of complex PDEs. Often the solution requires discretizing the physical domain into a mesh or grid then stepping from a given initial state towards some final state using small incremental time steps. Grid sizes can reach several thousand to hundreds of thousands of elements and the number of time steps required to solve the problem can vary from several thousand to tens of thousands or more. Traditional programming techniques are unable to take advantage of the non-random grid access patterns and generally …

Image Processing Techniques And Implementations In Software For Use With A Ccd Camera, Clarence Franklin Jr.

Opportunities for Undergraduate Research Experience Program (OURE)

The concept of image processing is used whenever there is a reference to digital images. By random and natural errors introduced into the image during collection and transmission, the images are distorted. Image processing techniques are used to eliminate these error before viewing of the images. For this experiment, the images provided by the ST-6 CCD Camera System will be used in the development and implementation of image processing techniques into a software package.

Course Scheduling Software: Reference Manual, Saadatu Gobir

Honors Projects

Welcome to version 1.0 of the Course Scheduling software. Course Scheduling is designed to meet needs of anyone who is tying to create a course schedule. This software is a product that compiles, links, and runs in C++; although it has C extension. It has been specifically designed to work In C++ exclusively. I had mixed a little of C++ functions with C structure programming to complete this package and make it more efficient. It is versatile, quick, and efficient. This instruction manual is brief, due to fact that the software is well documented. It only covers the basic functions …

Constraint Objects, Divesh Srivastava, Raghu Ramakrishnan, Peter Revesz

School of Computing: Conference and Workshop Papers

We describe the Constraint Object Data Model (CODM), which enhances an object-based data model with existential constraints to naturally represent partially specified information. We present the Constraint Object Query Language (COQL), a declarative, rule-based query language that can be used to infer relationships about and monotonically refine information represented in the CODM. COQL has a model-theoretic and an equivalent fixed-point semantics, based on the notions of constraint entailment and "proofs in all possible worlds." We also provide a novel polynomial-time algorithm for quantifier elimination for set-order constraints, a restricted class of set constraints that uses membership of subset-equal.

Benefits Of Using Team Choice For Windows As A Multi-Criteria Decision Making Group Decision Support System, Eddie Goggans

Mahurin Honors College Capstone Experience/Thesis Projects

Various experiments have been conducted over the past ten years using several different types of group decision support systems (GDSSs). Many previous GDSS designs have had success in these experiments with brainstorming but have been limited in providing judgment and choice support. TeamChoice for Windows is a multi-criteria decision making GDSS that is currently under development in an effort to overcome the limitations of previous systems and to significantly advance the capabilities of GDSSs. This paper discusses some of the general aspects of GDSSs, existing limitations, and explains the developments and use of TeamChoice for Windows as a multi-criteria decision …

Knowledge-Based Nonuniform Crossover, Harpal Maini, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

We present a new "knowledge-based non-uniform crossover" (KNUX) operator for genetic algorithms (GA's) that generalizes uniform crossover. We extend this to "Dynamic KNUX" (DKNUX), which constantly updates the knowledge extracted so far from the environment's feedback on previously generated chromosomes. KNUX can improve on good solutions previously obtained by using other algorithms. The modifications made by KNUX are orthogonal to other changes in parameters of GA's, and can be pursued together with any other proposed improvements. Whereas most genetic search methods focus on improving the move-selection procedures, after having chosen a fixed move-generation mechanism, KNUX and DKNUX make the move-generation …

Classification Characteristics Of Som And Art2, J. J. Aleshunas, Daniel C. St. Clair, William E. Bond

Mathematics and Statistics Faculty Research & Creative Works

Artificial neural network algorithms were originally designed to model human neural activities. They attempt to recreate the processes involved in such activities as learning, short term memory, and long-term memory. Two widely used unsupervised artificial neural network algorithms are the Self-Organizing Map (SOM) and Adaptive Resonance Theory (ART2). Each was designed to simulate a particular biological neural activity. Both can be used as unsupervised data classifiers. This paper compares performance characteristics of two unsupervised artificial neural network architectures; the SOM and the ART2 networks. The primary factors analyzed were classification accuracy, sensitivity to data noise, and sensitivity of the algorithm …

Generating Indexing Functions Of Regularly Sparse Arrays For Array Compilers, Scott Thibault, Lenore Mullin, Matt Insall

Computer Science Technical Reports

There are many applications involving arrays that contain non-zero components in regular geometric partitions. These include triangular, diagonal, tridiagonal, banded, etc. When computing with this type of arrays, they are usually stored in a packed form and computations are performed with only the non-zero components. This packed form requires an indexing function that maps an index of the array to an index of the packed lexico-graphically stored array. This paper presents a method of describing regular partitions and of automatically generating an indexing function from that description. These methods enable an array compiler to compile array operations on these type …

Polylog Depth Circuits For Integer Factoring And Discrete Logarithms, Jonathan P. Sorenson

Scholarship and Professional Work - LAS

AbstractIn this paper, we develop parallel algorithms for integer factoring and for computing discrete logarithms. In particular, we give polylog depth probabilistic boolean circuits of subexponential size for both of these problems, thereby solving an open problem of Adleman and Kompella.

Existing sequential algorithms for integer factoring and discrete logarithms use a prime base which is the set of all primes up to a bound B. We use a much smaller value for B for our parallel algorithms than is typical for sequential algorithms. In particular, for inputs of length n, by setting B = nlogdn with d a positive …

A Performance-Driven Routing Approach For Mcm-C, Qiong Yu

Masters Theses

In this paper, a new routing methodology for Ceramic MultiChip Module (MCM-C) is presented. In the proposed approach, the routing space is partitioned into several towers and the routing process is decomposed into three phases, namely, routing distribution, terminal assignment, and tower routing. During the routing distribution phase, the routing is uniformly distributed among towers. The locations of nets on the faces of each tower are assigned during the terminal assignment phase whereas the exact paths for the nets in each tower are determined during the tower routing phase.

The existing approaches to MCM routing are extensions of two-dimensional approaches …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 4, April 1994, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Genetic Algorithms And Artificial Life, Melanie Mitchell, Stephanie Forrest

Computer Science Faculty Publications and Presentations

Genetic algorithms are computational models of evolution that play a central role in many artificial-life models. We review the history and current scope of research on genetic algorithms in artificial life, giving illustrative examples in which the genetic algorithm is used to study how learning and evolution interact, and to model ecosystems, immune system, cognitive systems, and social systems. We also outline a number of open questions and future directions for genetic algorithms in artificial-life research

Maintaining Consistency Of Data In Mobile Distributed Environments, Evaggelia Pitoura, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

Tcp Buffering And Performance Over An Atm Network, Douglas E. Comer, John C. Lin

Department of Computer Science Technical Reports

No abstract provided.