Digital Commons Network^™

The Formal Description Of Resource Deadlock In Distributed Systems, P. Lu, B. Mcmillin

Computer Science Technical Reports

Deadlock detection is a fundamental problem in a distributed system and has been extensively studied in the past few years. Many distributed deadlock detection/resolution alg·orithms have been proposed, but most of them either have not given a correctness proof or have given an informal proof by using intuitive operational arguments. Informal arguments are prone to errors and many of the published algorithms have been fouud to be incorrect. In trying to avoid this situation, the development of a formal approach to the algorithm correctness proof is required.

In this work, a formal resource deadlock model with global and local clocks …

Production And Decay Of D1 (2420)0 And D2* (2460)0, Avery, P.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Feature And Model Selection In Feedforward Neural Networks, Jean M. Steppe

Theses and Dissertations

This research advances feature and model selection for feedforward neural networks. Feature selection involves determining a good feature subset given a set of candidate features. Model selection involves determining an appropriate architecture number of middle nodes for the neural network. Specific advances are made in neural network feature saliency metrics used for evaluating or ranking features, statistical identification of irrelevant noisy features, and statistical investigation of reduced neural network architectures and reduced feature subsets. New feature saliency metrics are presented which provide a more succinct quantitative measure of a features importance than other similar metrics. A catalogue of feature saliency …

Searching For Plans Using A Hierarchy Of Learned Macros And Selective Reuse, Douglas E. Dyer

Theses and Dissertations

This research presents a new approach to improving the performance of a macro planner: selective reuse. In macro planning, reuse can result in poorer performance than when planning with only primitive operators, a phenomenon that has been called the utility problem. The utility problem arises because the benefits of reuse are outweighed by the cost of retrieving a macro to reuse and the cost of searching through the larger search space caused by considering reuse candidates. Selective reuse contains the expansion of the search space by limiting the number of reuse candidates considered and limits the search required by considering …

Parallel Exact Enumeration Of Self-Avoiding Walk On Cubic Lattices And Its Applications To Protein Folding Studies, Anek Vorapanya

Theses

Exact enumeration of self-avoiding walk on many lattices have been studied extensively recently. Even a short chain polymer (about 30 monomers) represented as a chain of cubic lattice sites requires a considerable amount of computer time to exhaustively search for all unique conformations. However, self-avoiding walk process can be modified such that it exhibits a high degree of independence among subprocesses. Parallel implementation of such subprocesses can reduce a great amount of enumeration time. Parallel enumeration makes longer chain enumeration possible.

Enumerating only unique conformations requires that all rotation and mirror conformations be removed. An algorithm to avoid generating such …

Extracting Parallelism At Compile-Time Through Dependence Analysis & Cloning Techniques In An Object-Based Paradigm, Binoy Ravindran

Theses

The construct of Abstract Data Type (ADT) modules and Abstract Data Object (ADO) modules supported by most object-based languages are a great source for developing reusable code. To improve the run time performance of such object-based programs, we consider the asynchronous remote procedure call (ARPC) model of parallel execution, in which concurrency is achieved by having the caller and the callee (which are module instances) running on different processors. Frequently, an ADT module is needed simultaneously by other modules, thus causing contention. To resolve this, we clone the module instance in demand and distribute the copies across different processors, so …

Quickadvise - The Search For A More Efficient Method Of Advising, Gregory G. Pengiel '94

Honors Projects

In order to choose courses both efficiently and properly, a student and advisor must look at which courses have been taken, and also which ones are necessary. They must then determine whether or not the student is qualified to take the necessary courses. Unfortunately, there is no easy way to record and maintain this work so that it may be used throughout the college career.
Hence, even though the student and advisor recently determined which classes were headed, they must once again look up all relevant information and determine which courses are best. This is exactly the type of problem …

Fast Greedy Triangulation Algorithms, Matthew T. Dickerson, Robert L. Scot Drysdale, Scott A. Mcelfresh, Emo Welzl

Computer Science Technical Reports

The greedy triangulation of a set $S$ of $n$ points in the plane is the triangulation obtained by starting with the empty set and at each step adding the shortest compatible edge between two of the points, where a compatible edge is defined to be an edge that crosses none of the previously added edges. In this paper we present a simple, practical algorithm that computes the greedy triangulation in expected time $O(n \log n)$ and space $O(n)$ for points uniformly distributed over any convex shape. A variant of this algorithm should be fast for some other distributions. As part …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 5, May 1994, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Creation And Simulation Of A Model For A Discrete Time Buffer System With Interrupted Poisson Arrivals And Uncorrelated Server Interruptions, Susanne Naegele-Jackson

Masters Theses & Specialist Projects

A mathematical model for a discrete-time buffer system with both arrival and server interruptions is developed. In this model fixed-size packets arrive at the buffer according to a Poisson distribution and are stored there until they can be transmitted over the output channel. Service times are constant and the buffer is assumed to be of infinite size. Both arrival stream as well as the service of the packets are subjected to random interruptions described by Bernoulli processes, where the interruption process of the Poisson input stream is uncorrelated to the interruptions of the output line. Expressions are derived for the …

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 …

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).

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 …

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.

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 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 …