Digital Commons Network^™

Visual Knowledge Query Language As A Front-End To Relational Systems, Keng Siau, Kok Phuang Tan, Hock Chuan Chan

Research Collection School Of Computing and Information Systems

Relational query languages like SQL and QUEL require the users to understand the complex database structure. This is a burden on end users, especially novice end users who access the database on a casual and infrequent basis. To alleviate the need to know the logical database organization, this paper proposes the use of a semantic data model, known as the Enhanced Entity-Relationship (EER) model, as a front-end to the relational systems. A formal, high-level Visual Knowledge Query Language (VKQL) has also been designed for this interface. This language provides for knowledge abstraction as the user communicates only domain knowledge with …

A Topological Model For Parallel Algorithm Design, Jeffrey A. Simmers

Theses and Dissertations

This research demonstrates that formal, mathematical analysis in theoretical computer science can be recast in terms of the topology of complete metric spaces, and also presents a methodical technique for developing formal specifications. This effort shows that the topology of complete metric spaces provides a tool that can be used to both recreate major results about computational models and also to develop new results about these models. Using the two computational models CSP and UNITY, this effort shows that the required mathematics needed to support this alternative to the traditional analysis of computational models can be readily supported by a …

Education Necessary For Air Force Software Managers To Use The Ada Programming Language And Software Engineering Effectively, James W. Worley Jr.

Theses and Dissertations

This research investigated the perceived Ada and software engineering education needs of software managers throughout the Air Force and provided recommendations to Air Staff for developing the education. Since the Department of Defense mandated all DOD agencies use the Ada programming language for software development, the education of the personnel who have to support the policy has lagged behind the implementation Ada is not a simple language to use and is only fully effective if used with sound software engineering principles. A survey was given to Air Force mid-level personnel who manage software in some capacity. Of the software personnel …

An Expert System Job Aid For Users Of The Automated Scheduling Module, Kevin A. Gore

Theses and Dissertations

This research developed an Expert System for novice aircraft maintenance schedulers (AFSC: 392XX) with little experience using the Automated Scheduling Module (ASM). First, an in-depth literature review was completed. Next, personal interviews were conducted with an ASM expert and other 392XX personnel. Prototypes using VP-Expert and KnowledgePro shells were created. The knowledgePro shell was selected to create the ASM Job Aid, combining the knowledge of the expert and AFM 66-279. The program was verified, validated, and favorably reviewed by 392XX personnel. Recommendations include: The Air Force Logistics Management Center (AFLMC) examine the ASM Job AId and develop a Performance Support …

Heuristics For Hospital Inventory Management, Thomas G. Hibson

Theses and Dissertations

This study investigated the reasoning strategies used by hospital logistics management experts and was conducted at the Wright-Patterson AFB (WPAFB) Medical Center. An expert system was developed to verify the captured strategies. The particular area of interest of this study was the reasoning strategies involved in the reconciliation of the Monthly Stock Status Report within the Medical Logistics Branch. A literature review revealed there were few guidelines as to when and what action to pursue when reconciling the Monthly Stock Status Report. Though there were no references in the literature on expert systems that dealt with this particular report, there …

Work-Preserving Real-Time Emulation Of Meshes On Butterfly Networks, Alf-Christian Achilles

Theses

The emulation of a guest network G on a host network H is work-preserving and real-time if the inefficiency, that is the ratio W_G/W_H of the amounts of work done in both networks, and the slowdown of the emulation are O(1).

In this thesis we show that an infinite number of meshes can be emulated on a butterfly in a work-preserving real-time manner, despite the fact that any emulation of an s x s-node mesh in a butterfly with load 1 has a dilation of Ω(logs).

The recursive embedding of a mesh in a butterfly presented by …

The Ganith Algebraic Geometry Toolkit V 1.0, Chanderjit Bajaj, Andrew V. Royappa

Department of Computer Science Technical Reports

No abstract provided.

The Vaidak Medical Imaging And Model Reconstruction Toolkit, Brian Bailey, Chanderjit Bajaj, Malcolm C. Fields

Department of Computer Science Technical Reports

No abstract provided.

Computer Viruses And Ethics, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

C1 Smoothing Of Polyhedra With Implicit Surface Patches, Chanderjit L. Bajaj, Insung Ihm

Department of Computer Science Technical Reports

No abstract provided.

Formal Methods Of Real-Time Systems, Su-Mei Tsai, Bruce M. Mcmillin

Computer Science Technical Reports

Formal aid in specification and verification techniques have become an accepted approach to achieving reliable software for life-critical real-time systems, in which testing may be impossible or too dangerous, since the real inputs to the systems come from the real world. Modelling, assertion languages, and proof systems are three major components that are employed to accomplish the confidence of safe real-time environments. This paper examines these currently available techniques that are used for safety analysis of real-time systems.

Application-Oriented Fault-Tolerant Parallel Branch & Bound, Aggie Sun, Bruce M. Mcmillin

Computer Science Technical Reports

An important aspect which is often overlooked in the software design cycle is the question of reliability. Many methodologies in the past have attempted to provide reliability efficiently but have never been successful at eliminating explicit time and space redundancy. The approach taken here is based on the Application-Oriented Fault Tolerance Paradigm which provides reliability by examining the behavior and properties of the application. This paper will demonstrate how fault detecting constraints are developed and incorporated using the Application-Oriented Fault Tolerance paradigm for the class of Branch and Bound algorithms. Branch and bound algorithms are a type of combinatorial search …

Semi-Distributed Load Balancing For Massively Parallel Multicomputer Systems, Ishfaq Ahmad, Arif Ghafoor

Electrical Engineering and Computer Science - Technical Reports

This paper presents a semi-distributed approach, for load balancing in large parallel and distributed systems, which is different from the conventional centralized and fully distributed approaches. The proposed strategy uses a two-level hierarchical control by partitioning the interconnection structure of a distributed or multiprocessor system into independent symmetric regions (spheres) centered at some control points. The central points, called schedulers, optimally schedule tasks within their spheres and maintain state information with low overhead. We consider interconnection structures belonging to a number of families of distance transitive graphs for evaluation, and using their algebraic characteristics, show that identification of spheres and …

Explicit Clock Temporal Logic In Timing Constraints For Real-Time Systems, S. Ramanna, J. F. Peters Iii

Electrical Engineering and Computer Science - Technical Reports

A form of explicit clock temporal logic (called TLrt) useful in specifying timing constraints on controller actions, a real-time database (rtdb) items, and constraints in a real-time constraint base (rtcb), is presented. Timing as well as other forms of constraints are stored in the rtcb. A knowledge-based approach to ensure the integrity of information in an rtdb is given. The rtcb is realized as a logic program called Constrainer, which is a historyless integrity checker for a real-time database. The consistency and integrity issues for an rtcb and rtdb are investigated. The formal bases for a temporally complete rtdb and …

Multi Cast Routing In Unreliable Networks, Martina Schollmeyer, Bruce M. Mcmillin

Computer Science Technical Reports

The efficient routing of messages in a multicomputer interconnection network is the key to the performance of such a network. Multicast communication refers to the delivery of a message from a source node to several destination nodes. Although multicast is highly desirable for many applications, it is not directly supported in most multicomputer architectures. This paper examines existing algorithms for multicast routing in multicomputer networks and groups them into a number of categories such as multicast trees, multicast paths, multicast stars, etc. These algorithms are evaluated in terms of deadlock handling, adaptability and suitability for wormhole routing. Wormhole routing is …

Collision Detection And Analysis In A Physically Based Simulation, William J. Bouma, George Vanĕček

Department of Computer Science Technical Reports

No abstract provided.

Formal Generation Of Executable Assertions For A Fault-Tolerant Parallel Bitonic Sort, Hanan Lutfiyya, Bruce M. Mcmillin

Computer Science Technical Reports

No abstract provided.

Selective Inheritance And Overriding In Statically-Typed Object-Oriented Languages, Ryan Stansifer, Dan Wetklow

Department of Computer Science Technical Reports

No abstract provided.

Multidimensional Digital Searching And Some New Parameters In Tries, Peter Kirschenhofer, Helmut Prodinger, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

The Complexity Of Local Stratification, Peter Cholak, Howard A. Blair

Electrical Engineering and Computer Science - Technical Reports

The class of locally stratified logic programs is shown to be Π11-complete by the construction of a reducibility of the class of infinitely branching nondeterministic finite register machines.nondeterministic finite register machines.

Fault-Tolerant Load Management For Real-Time Distributed Computer Systems, Arif Ghafoor, Ishfaq Ahmad

Electrical Engineering and Computer Science - Technical Reports

This paper presents a fault-tolerant scheme applicable to any decentralized load balancing algorithms used in soft real-time distributed systems. Using the theory of distance-transitive graphs for representing topologies of these systems, the proposed strategy partitions these systems into independent symmetric regions (spheres) centered at some control points. These central points, called fault-control points, provide a two-level task redundancy and efficiently re-distribute the load of failed nodes within their spheres. Using the algebraic characteristics of these topologies, it is shown that the identification of spheres and fault-control points is, in general, is an NP-complete problem. An efficient solution for this problem …

Constructing Real-Time Systems From Temporal I/O Automata, J. F. Peters Iii, S. Ramanna

Electrical Engineering and Computer Science - Technical Reports

A new class of communicating automata called Temporal Input/Output Automata (TAi/os) is introduced. A TAi/o is a predicate automaton used to specify real-time systems. The specification provided by a TAi/o includes state predicates with proof expressions and abstract program syntax as attributes. An abstract program is extracted during a constructive proof of the specification using the proof expressions. A TAi/o specification also includes hard, real-time constraints on program behavior. The predictability of deterministic, temporally complete TAi/o is investigated. The formulation of real-time system transductions and transduction rules for TAi/os in explicit clock temporal logic is given. An illustration of the …

The Spectrum Simulation System: A Formal Approach To Distributed Algorithm Development Tools, Kenneth J. Goldman

All Computer Science and Engineering Research

We present the Spectrum Simulation System, a new research tool for the design and study of distributed algorithms. Based on the formal Input/Output Automation model of Lynch and Tuttle, Spectrum allows one to express distributed algorithms as collections of I/O automata and simulate them directly in terms of the semantics of that model. This permits integration of algorithm specification, design, debugging, analysis, and proof of correctness within a single formal framework that is natural for describing distributed algorithms. Spectrum provides a language for expressing algorithms as I/O automata, a simulator for generating algorithm executions, and a graphics interface for constructing …

Rapid Display Of Radiographic Images, Jerome R. Cox Jr., Stephen M. Moore, Robert A. Whitman, G. James Blaine, R. Gilbert Jost, L. Magnus Karlsson, Thomas L. Monsees, Gregory L. Hansen, Timothy C. David

All Computer Science and Engineering Research

The requirements for the rapid display of radiographic images exceed the capabilities of widely available display, computer and communication technologies. Computed radiography captures data with a resolution of about four megapixels. Large format displays are available that can present over four megapixels. One megapixel displays are practical for use in combination with large format displays and in areas where the viewing task does not require primary diagnosis. This paper describes an electronic radiology system that approximates the highest quality systems, but through the use of several interesting techniques allows the possibility of its widespread installation throughout hospitals. The techniques uses …

Composition, Superposition, And Encapsulation In The Formal Specification Of Distributed Systems, Kenneth J. Goldman

All Computer Science and Engineering Research

Composition, superposition, and encapsulation are important techniques that work well together for designing large distributed software systems. Composition is a symmetric operator that allows system components to communicate with each other across module boundaries. Superposition is an asymmetric relationship that allows one system component to observe the state of another. Encapsulation is the ability to define the reason about the behavior of a module in terms of a well-defined boundary between that module and its environment, while hiding the internal operations of that module. In this paper, the I/O automation model of Lynch and Tuttle is extended to permit superposition …

A Generic Multiplication Pipeline, Per Brinch Hansen

Electrical Engineering and Computer Science - Technical Reports

This paper illustrates the benefits of developing generic algorithms for parallel programming paradigms which can be adapted to different applications. We consider a combinatorial problem called tuple multiplication. This paradigm includes matrix multiplication and the all-pairs shortest paths problem as special cases. We develop a generic pipeline for tuple multiplication. From the generic algorithm we derive pipelines for matrix multiplication and shortest paths computation by making substitutions of data types and functions. The performance of the matrix multiplication pipeline is analyzed and measured on a Computing Surface.

Fast Parallel Algorithms For Basic Problems, Zhaofang Wen

Computer Science Theses & Dissertations

Parallel processing is one of the most active research areas these days. We are interested in one aspect of parallel processing, i.e. the design and analysis of parallel algorithms. Here, we focus on non-numerical parallel algorithms for basic combinatorial problems, such as data structures, selection, searching, merging and sorting. The purposes of studying these types of problems are to obtain basic building blocks which will be useful in solving complex problems, and to develop fundamental algorithmic techniques.

In this thesis, we study the following problems: priority queues, multiple search and multiple selection, and reconstruction of a binary tree from its …

Philco: Some Recollections Of The Philco Transac S-2000, Saul Rosen

Department of Computer Science Technical Reports

No abstract provided.

Porting Ncube Packages To Ipsc/860 And Ipsc/2 Hypercubes, Jingwen Wang, Mo Mu

Department of Computer Science Technical Reports

No abstract provided.

Negotiating And Supporting Interdependent Data In Very Large Federated Database Systems, Ahmed K. Elmagarmid, James G. Mullen

Department of Computer Science Technical Reports

No abstract provided.