Digital Commons Network^™

Highly Concurrent Logically Synchronous Multicast, Kenneth J. Goldman

All Computer Science and Engineering Research

We define the logically synchronous multicast problem, which imposes a natural and useful structure on message delivery order in an asynchronous system. In this problem, a computation proceeds by a sequence of multicasts, in which a process sends a message to some arbitrary subset of the processes, including itself. A logically synchronously multicast protocol must make it appear to every process as if each multicast occurs simultaneously at all participants of that multicast (sender plus receivers). Furthermore, if a process continually wishes to sends a message, it must eventually be permitted to do so. We present a highly concurrent solution …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, October 1990, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

A Software Design Tool For Predictable Performance In Real-Time, Data Flow Architectures, Brij Mohan V. Mandala

Electrical & Computer Engineering Theses & Dissertations

A software design tool which aids in the performance evaluation and selection of operating points for an algorithm implemented in ATAMM defined data flow architectures is presented in this thesis. ATAMM (Algorithm To Architecture Mapping Model) is a new graph theoretic model developed by researchers at Old Dominion University and the NASA-Langley Research Center. ATAMM is capable of modeling the execution of large-grained algorithms on distributed data flow architectures. A software tool is required for predicting the performance, determining the resource requirements and for selecting suitable operating points for an ATAMM based system. The ATAMM Design Tool presented in this …

Domain Decomposer: A Software Tool For Mapping Pde Computations To Parallel Architectures, N. P. Chrisochoides, C. E. Houstis, Elias N. Houstis, P. N. Papachiou, S. K. Kortesis

Department of Computer Science Technical Reports

No abstract provided.

Global Concurrency Control In Heterogeneous Distributed Database Systems, Ahmed K. Elmagarmid, Weimin Du, Yungho Leu

Department of Computer Science Technical Reports

No abstract provided.

Generalized Quasi Serializability Theory, Weimin Du, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.

How To Construct The Skeleton Of Csg Objects, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

A Colored Petri Net-Based Approach For Automated Deadlock Detection In Parallel Programs, N. Mansouri, Amrit L. Goel

Electrical Engineering and Computer Science - Technical Reports

A static analysis approach is proposed for automated detection of deadlocks in a common class of parallel programs, referred to as Single Code Multiple Data (SCMD) programs. It is based on colored Petri net (CP-net) modeling and reachability analysis, where colors correspond to parallel processes. An SCMD program is first translated into a CP-net and a reachability tree is then derived and analyzed for deadlock information. CP-subnets representing basic programming language constructs are described. These subnets are employed as building blocks by an algorithm that translates synchronization-related statements of a process in an SCMD program and connects the resulting subnets. …

An Approach For Minimizing Spurious Errors In Testing Ada Tasking Programs, N. Mansouri, Amrit L. Goel

Electrical Engineering and Computer Science - Technical Reports

We propose an approach for detecting deadlocks and race conditions in Ada tasking software. It is based on an extension to Petri net-based techniques, where a concurrent program is modeled as a Petri net and a reachability graph is then derived and analyzed for desired information. In this approach, Predicate-Action subnets representing Ada programming constructs are described, where predicates and actions are attached to transitions. Predicates are those found in decision statements. Actions involve updating the status of the variables that affect the tasking behavior of the program and updating the Read and Write sets of shared variables. The shared …

A Petri Net-Based Tool For Detecting Deadlocks And Race Conditions In Concurrent Programs, Amrit L. Goel, N. Mansouri

Electrical Engineering and Computer Science - Technical Reports

A static analysis tool for detecting deadlocks and potential race conditions on shared variables in concurrent programs is presented. It is based on Petri Net modeling and reachability analysis, where a concurrent program is modeled as an augmented Petri net and a reachability graph is then derived and analyzed for desired information. Place-Transition subnets representing programming language constructs are described. Transitions in these subnets are augmented with sets of shared variables that occur in sections of the program, called concurrency zones, related to the transitions. The tool consists of four modules. The modeling module employs the augmented subnets as building …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, September 1990, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Unification In Modal Theorem Proving, Xiaolin Zhang, Chilukuri K. Mohan

Electrical Engineering and Computer Science - Technical Reports

Modal formulas can be proved by translating them into a three-typed logic and then using unification and resolution, with axioms describing properties of the reachability relation among possible worlds. In this paper, we improve on the algorithms in [1], showing that "strong skolemisation" and occurrence checks are not needed for proving theorems of Q, T, Q4, and S4. We also extend the 'path logic' approach to S5, give the appropriate unification algorithm, and prove its correctness.

Studies In The Hybrid Deterministic Parsing, Stan C. Kwasny, Anne M. Johnstone, Barry L. Kalman

All Computer Science and Engineering Research

This report details research plans to extend work on hybrid deterministic parsing. The approach is hybrid in its combination of symbolic and sub-symbolic (connectionist) approaches. The research is investigating (1) new and more robust architectures for deterministic parsing which are hybrid mixtures of symbolic and sub-symbolic components, (2) combinations of syntax with lexical access and other components of natural language processing in order to determine how the distributed patterns of connectionism may enable better interfaces among these components, and (3) properties of the rules in the rule-based deterministic processing of natural language that make them most suitable for sub-symbolic training. …

Gateway Design For Lan Interconnection Via Isdn, Xian-Yu Zhang, Robert H. Deng

Research Collection School Of Computing and Information Systems

Recently, the use of bridges/gateways to interconnect physically distant local area networks (LANs) has become increasingly popular. There are various ways of connecting these bridges/gateways. ISDN is one of them and an attractive one. In this paper we discuss our work in the gateway design for interconnecting LANs via ISDN.

Notions Of Relative Ubiquity For Invariant Sets Of Relational Structures, Paul Bankston, Wim Ruitenburg

Mathematics, Statistics and Computer Science Faculty Research and Publications

Given a finite lexicon L of relational symbols and equality, one may view the collection of all L-structures on the set of natural numbers w as a space in several different ways. We consider it as: (i) the space of outcomes of certain infinite two-person games; (ii) a compact metric space; and (iii) a probability measure space. For each of these viewpoints, we can give a notion of relative ubiquity, or largeness, for invariant sets of structures on w. For example, in every sense of relative ubiquity considered here, the set of dense linear orderings on w is …

The Origins Of Modern Computing, Saul Rosen

Department of Computer Science Technical Reports

No abstract provided.

Curvature Computations On Surfaces In N-Space, Jung-Hong Chuang, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

Multisearch Techniques Of Hierarchical Dags On Mesh-Connected Computers, With Applications, Jyh-Jong Tsay, Mikhail J. Atallah

Department of Computer Science Technical Reports

No abstract provided.

Computing Some Distance Functions Between Polygons, Mikhail J. Atallah, Celso C. Ribeiro, Sergio Lifschitz

Department of Computer Science Technical Reports

No abstract provided.

History Of The Computer Sciences Department At Purdue University, John R. Rice, Saul Rosen

Department of Computer Science Technical Reports

No abstract provided.

The Origins Of Computing And Computer Science At Purdue University, Saul Rosen, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Robot Pedagogics: The Adaptation, Analysis, And Computer Control Of A Model Manipulator, Edward T. Hammerand, Chung You Ho

Computer Science Technical Reports

The subject of robotics is addressed by many different fields, among them computer science, electrical engineering, and mechanical engineering. This work is an attempt to bring together all of these aspects from the perspective of a computer science background. Different techniques are considered and reconciled with one another in the analytical area, while detail and explanation are added in all areas that were not previously available. In addition, geometrical interpretations arc presented for concepts that have heretofore been presented only in the form of equations.

Mesh And Pyramid Algorithms For Iconic Indexing, Alok Choudhary, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

In this paper parallel algorithms on meshes and pyramids for iconic indexing are presented. Our algorithms are asymptotically superior to previously known parallel algorithms.

Ctran: Transforming Scientific Fortran Programs To Unix Based Computing Environments, Qi Chen

Masters Theses

FORTRAN is one of the most popular scientific programming languages. The efficiency, rich libraries, and popularity of FORTRAN support its continued use as a programming language for scientific computing in the near future. However, in current multiprocessor UNIX environments, C is often better supported. The desire to use existing FORTRAN subroutines within such a C environment leads to several options. In this thesis, we introduce a "modern" scientific programming language called CTRAN for this purpose.

We begin with a brief review of the history of scientific programming languages. An introduction of CTRAN is given in Chapter HI. In Chapter IV, …

The Cops Security Checker System, Daniel Farmer, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

Encoding Phonetic Knowledge For Use In Hidden Markov Models Of Speech Recognition, Danming Qian

Electrical & Computer Engineering Theses & Dissertations

Hidden Markov models (HMM's) have achieved considerable success for isolated-word speaker-independent automatic speech recognition. However, the performance of an HMM algorithm is limited by its inability to discriminate between similar sounding words. The problem arises because all differences between speech patterns are treated as equally important. Thus the algorithm is particularly susceptible to confusions caused by phonetically-irrelevant differences. This thesis presents two types of preprocessing schemes as candidates for improving HMM performance. The aim is to maximize the differences between phonologically-distinct speech sounds while minimizing the effect of variations in phonologically-equivalent speech sounds. The preprocessors presented are a discrete cosine …

Visual Speech Training Aid For The Deaf, Subhashri Venkat

Electrical & Computer Engineering Theses & Dissertations

A computer-based vowel articulation training aid has been developed. A "continuous" acoustic-phonetic transformation is performed to map speech parameters to a lower dimensionality display space. There are two possible approaches to this transformation problem. The transformation could be either linear or a combination nonlinear/linear. The nonlinear transformation is performed using a multi-layered feedforward neural network with linear output layers. Speech parameters are extracted either from an analog filter bank arrangement (band energies) or by a digital signal processing procedure (Discrete Cosine Transform Coefficients). The speech parameters obtained from both methods correspond to the spectral envelope of the speech signals. The …

An Artificial Neural Approach To The Decomposition Problem, Chandrashekar L. Masti

Electrical & Computer Engineering Theses & Dissertations

The goal of this thesis is to develop an artificial neural approach toward addressing the intractability involved with the decomposition problem. The search for the lattice of substitution property (s. p.) partitions essential to decompositions is cast into the framework of constraint satisfaction. An artificial neural network is developed to provide solutions by performing optimization of a mathematically derived objective function over the problem space. The issue of transitivity is verified to belong to a class of problems beyond the scope of solvability for conventional quadratic-order constraint satisfaction neural networks. A theorem is stated and proved establishing that third-order correlations …

Typed Token Approach For Database Processing During Network Partitioning, Bharat Bhargava, Shy-Renn Lian

Department of Computer Science Technical Reports

No abstract provided.

A Data Structure For Analyzing Collisions Of Moving Objects, George Vanecek

Department of Computer Science Technical Reports

No abstract provided.