Computer Sciences Commons^™

Representing And Learning Propositional Logic In Symmetric Connectionist Networks, Gadi Pinkas

All Computer Science and Engineering Research

The chapter presents methods for efficiently representing logic formulas in connectionist networks that perform energy minimization. Algorithms are given for transforming any formula into a network in linear time and space and for learning representations of unknown formulas by observing examples of satisfying truth assignments. The relaxation process that underlies networks of energy minimization reveals an efficient hill climbing algorithm for satisfiability problems. Experimental results indicate that the parallel implementation of the algorithm with give extremely good average-case performance, even for large-scale, hard satisfiability problems (randomly generated).

An Optimal Nonblocking Multicast Virtual Circuit Switch, Jonathan S. Turner

All Computer Science and Engineering Research

This paper describes an architecture for a multicast virtual circuit switch using cell recycling. This is the first nonblocking switch architecture that is optimal in both the switching network complexity and the amount of memory required for multicast address translation. Furthermore, it is optimal in the amount of effort required for multicast connection modification. This architecture makes it both technically and economically feasible to construct the large switching systems that will ultimately be needed for wide scale deployment of Broadband ISDN to residential users. In particular, we estimate that systems with tens of thousands of 620 Mb/s ports can be …

Segmentation/Recognition Of Hand-Written Numeral Characters, Khalid Sherdil

All Computer Science and Engineering Research

This thesis describes a number of techniques for segmenting non-cursive handwritten digits into individual characters. It strongly emphasizes on a recognition-segmentation algorithm, which uses the linear regression method to recognize those strokes which consist of one or more straight-lined parts. A new method of sampling the pen data according to the pen speed, hence giving a more uniform points concentratino distribution, is also introduced. It is shown how several of our segmenting techniques, such as relative stroke lengths, relative stroke positions, order of stroke entry, stroke direction, stroke intersection, etc. can be combined to yield success results of about 95%.

Learning Unions Of Boxes With Membership And Equivalence Queries, Paul W. Goldberg, Sally A. Goldman, H. David Matthias

All Computer Science and Engineering Research

We present two algorithms that use membership and equivalence queries to exactly identify the concepts given by the union of s discretized axis-parallel boxes in d-dimensional discretized Euclidean space where each coordinate can have n discrete values. The first algorithm receives at most s*d counterexamples and uses time and membership queries polynomial in s and logn for d any constant. Further, all equivalence queries made can be formulated as the union of O(s*d*log(s)) axis-parallel boxes. Next, we introduce a new complexity measure that better captures the complexity of a union of boxes than simply the number of boxes and dimensions. …

The Washington University Multimedia Explorer, William D. Richard, Jerome R. Cox Jr., A. Maynard Engebretson, Jason Fritts, Craig Horn

All Computer Science and Engineering Research

The Washington University MultiMedia eXplorer (MMX) is a complete, host-independent multimedia system capable of transmitting and receiving JPEG-compressed video, CD-quality audio, and high-resolution radiographic images over the Washington University broadband ATM network. If the host is equipped with an ATM interface card, normal network traffic is supported via "T" and "Y" connections. The MMX consists of an ATMizer and three multimedia subsystems. The ATMizer implements the host interface, the interface to the ATM network, and the interface to the three multimdeia channels. This paper describes the architecture of the MMX, the software used with the system, and the applications which …

A Methodology For Developing High Performance Computing Models: Storm-Scale Weather Prediction, Nikos Chrisochoides, Kelvin Droegemeier, Geoffrey C. Fox, Kim Mills, Ming Xue

Northeast Parallel Architecture Center

A methodology for developing future generations of a storm-scale weather prediction model for Massively Parallel Processing is described. The forecast model is the Advanced Regional Prediction System (ARPS), a three-dimensional, fully compressible, non-hydrostatic predictive model. In the short term, the computational goals include developing a portable, scalable model for distributed memory SIMD and MIMD architectures, while preserving a high degree of modularity to support rapid design and validation, maintainability, educational goals and operational testing. Longer term computational goals include a parallel adaptive mesh refinement scheme. A FortranD/High Performance Fortran version of the ARPS provides portability in the current version of …

Fortran 90d/Hpf Compiler For Distributed Memory Mimd Computers: Design, Implementation, And Performance Results, Zeki Bozkus, Alok Choudhary, Geoffrey C. Fox, Tomasz Haupt

Northeast Parallel Architecture Center

Fortran 90D/HPF is a data parallel language with special directives to enable users to specify data alignment and distributions. This paper describes the design and implementation of a Fortran90D/HPF compiler. Techniques for data and computation partitioning, communication detection and generation, and the run-time support for the compiler are discussed. Finally, initial performance results for the compiler are presented which show that the code produced by the compiler is portable, yet efficient. We believe that the methodology to process data distribution, computation partitioning, communication system design and the overall compiler design can be used by the implementors of HPF compilers.

A Compilation Approach For Fortran 90d/Hpf Compilers On Distributed Memory Mimd Computers, Zeki Bozkus, Alok Choudhary, Geoffrey C. Fox, Tomasz Haupt

Northeast Parallel Architecture Center

This paper describes a compilation approach for a Fortran 90D/HPF compiler, a source-to-source parallel compiler for distributed memory systems. Different from Fortran 77 parallelizing compilers, a Fortran90D/HPF compiler does not parallelize sequential constructs. Only parallelism expressed by Fortran 90D/HPF parallel constructs is exploited. The methodology of parallelizing Fortran programs such as computation partitioning, communication detection and generation, and the run-time support for the compiler are discussed. An example of Gaussian Elimination is used to illustrate the compilation techniques with performance results.

Integrating Multiple Programming Paradigms On Connection Machine Cm5 In A Dataflow-Based Software Environment, Gang Cheng, Geoffrey C. Fox, Kim Mills

Northeast Parallel Architecture Center

By viewing different parallel programming paradigms as essential heterogeneous approaches in mapping "real-world" problems to parallel systems, we discuss methodologies in integrating multiple programming models on a Connection Machine CM5. In a data flow based integration model built in a visualization software AVS, we demonstrate a simple, effective and modular way to couple sequential, data-parallel and explicit message-passing modules into an integrated programming environment on the CM5.

The Multicomputer Toolbox - First-Generation Scalable Libraries, Anthony Skjellum, Alvin Leung, Steven G. Smith, Robert D. Falgout

Northeast Parallel Architecture Center

"First-generation" scalable parallel libraries have been achieved, and are maturing, within the Multicomputer Toolbox. The Toolbox includes sparse, dense, iterative linear algebra, a stiff ODE/DAE solver, and an open software technology for additional numerical algorithms, plus an inter-architecture Makefile mechanism for building applications. We have devised C-based strategies for useful classes of distributed data structures, including distributed matrices and vectors. The underlying Zipcodemessage passing system has enabled process-grid abstractions of multicomputers, communication contexts, and process groups, all characteristics needed for building scalable libraries, and scalable application software. We describe the data-distribution-independent approach to building scalable libraries, which is needed so …

A Message Passing Interface For Parallel And Distributed Computing, Salim Hariri, Jongbaek Park, Fang-Kuo Yu, Manish Parashar

Northeast Parallel Architecture Center

The proliferation of high performance workstations and the emergence of high speed networks have attracted a lot of interest in parallel and distributed computing (PDC). We envision that PDC environments with supercomputing capabilities will be available in the near future. However, a number of hardware and software issues have to be resolved before the full potential of these PDC environments can be exploited. The presented research has the following objectives: (1) to characterize the message-passing primitives used in parallel and distributed computing; (2) to develop a communication protocol that supports PDC; and (3) to develop an architectural support for PDC …

Hierarchical Tree-Structures As Adaptive Meshes, David J. Edelsohn

Northeast Parallel Architecture Center

Introduction: Two basic types of simulations exist for modeling systems of many particles: grid-based (point particles indirectly interacting with one another through the potential calculated from equivalent particle densities on a mesh) and particle-based (point particles directly interacting with a one another through potentials at their positions calculated from the other particles in the system). Grid-based solvers traditionally model continuum problems, such as fluid and gas systems, and mixed particle-continuum systems. Particle-based solvers find more use modeling discrete systems such as stars within galaxies or other rarefied gases. Many different physical systems, including electromagnetic interactions, gravitational interactions, and fluid vortex …

An Interpretive Framework For Application Performance Prediction, Manish Parashar, Salim Hariri, Tomasz Haupt, Geoffrey C. Fox

Northeast Parallel Architecture Center

Software development in parallel/distributed environment is a non-trivial task and depends greatly on the availability of appropriate support in terms of development tools and environments. Performance prediction /evaluation tools form a critical part of any software development environment as they enable the developer to visualize the effects of various design choices on the performance of the application. This paper presents an interpretive model for a source driven performance prediction framework. A prototype framework based on the proposed model has been developed for the iPSC/860 system. Numerical results obtained on this system are presented. These results confirm the potential of interpretive …

Complete Exchange On A Wormhole Routed Mesh, Rajeev Thakur, Alok Choudhary, Geoffrey C. Fox

Northeast Parallel Architecture Center

The complete exchange (or all-to-all personalized) communication pattern occurs frequently in many important parallel computing applications. We discuss several algorithms to perform complete exchange on a two dimensional mesh connected computer with wormhole routing. We propose algorithms for both powerof -two and non power-of-two meshes as well as an algorithm which works for any arbitrary mesh. We have developed analytical models to estimate the performance of the algorithms on the basis of system parameters. These models take into account the effects of link contention and other characteristics of the communication system. Performance results on the Intel Touchstone Delta are presented …

Binary Resolution In Surface Reasoning, William C. Purdy

Electrical Engineering and Computer Science - Technical Reports

Intuition suggests the hypothesis that everyday human reasoning is conducted in the written or spoken natural language, rather than in some disparate representation into which the surface language is translated. An examination of human reasoning reveals patterns of inference that parallel binary resolution. But any standard implementation of resolution requires Skolemization. Skolemization would seem an unlikely component of human reasoning. This appears to contradict the hypothesis that human reasoning takes place at the surface. To reconcile these observations, this paper develops a new rule of inference, which operates on surface expressions directly. This rule is shown to produce results which …

Genetic Algorithms For Stochastic Flow Shop No Wait Scheduling, Harpal Maini, Ubirajara R. Ferreira

Electrical Engineering and Computer Science - Technical Reports

ln this paper we present Genetic Algorithms - evolutionary algorithms based on an analogy with natural selection and survival of the fittest - applied to an NP Complete combinatorial optimization problem: minimizing the makespan of a Stochastic Flow Shop No Wait (FSNW) schedule. This is an important optimization criteria in real-world situations and the problem itself is of practical significance. We restrict our applications to the three machine flow shop no wait problem which is known to be NP complete. The stochastic hypothesis is that the processing times of jobs are described by normally distributed random variables. We discuss how …

Multimedia Object Modelling And Storage Allocation Strategies For Heterogeneous Parallel Access Storage Devices In Real Time Multimedia Computing Systems, C.Y. Roger Chen, Kingsley C. Nwosu, P. B. Berra

Electrical Engineering and Computer Science - All Scholarship

The improvements in disk speeds have not kept up with improvements in processor and memory speeds. Conventional storage techniques, in the face of multimedia data, are inefficient and/or inadequate. Here, an efficient multimedia object allocation strategy is presented. We describe a multimedia object model, the object and storage device characteristics, and the fragmentation strategy. A bipartite graph approach is used for mapping fragments to storage devices and a cost function is used to determine an efficient allocation of an object and to balance the loads on the devices.

Graduate Bulletin, 1993-1995, Moorhead State University

Graduate Bulletins (Catalogs)

No abstract provided.

On Transactional Workflows, Amit P. Sheth, Marek Rusinkiewicz

Kno.e.sis Publications

The basic transaction model has evolved over time to incorporate more complex transactions structures and to take the advantage of semantics of higher-level operations that cannot be seen at the level of page reads and writes. Well known examples of such extended transaction models include nested and multi-level transactions. A number of relaxed transaction models have been defined in the last several years that permit a controlled relaxation of the transaction isolation and atomicity to better match the requirements of various database applications. Correctness criteria other than global serializability have also been proposed. Several examples of extended/relaxed transaction models are …

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 …

An Object Oriented Preemptive Multitasking Kernel, Lee Gene Shipman

Masters Theses

“This paper describes a preemptive multitasking kernel designed and coded using C++ using an object oriented paradigm. The kernel design, while implemented on an Intel 80386 based IBM PC running MS-DOS 4.01, can be ported to any platform, rewriting only the low level, hardware specific code.

The kernel, in application framework form, enables the applications developer to create real-time multitasking applications. This can be done in a systematic way by capitalizing on the power of object oriented program development.

A simulation was created to verify the correctness of the kernel against a traditional non-multitasking approach. This simulation provides the proof …

X.500 Directory Service Support For Electronic Mail, Mihai G. Sirbu

Masters Theses

"One of the difficult problems on the Internet is finding the electronic mail addresses of users. In practice, there are some indirect ways of finding these addresses such as the finger program in UNIX, but almost all of these methods require the user to know the exact host name of the destination. What is most desirable is an automated mechanism which provides the e-mail addresses of users if some minimal information about the destination site is known.

This thesis describes the design of such a directory service support system, based on the X.500 Series of CCITT Recommendation, for the elm …

Practical Prefetching Techniques For Multiprocessor File Systems, David Kotz, Carla Schlatter Ellis

Dartmouth Scholarship

Improvements in the processing speed of multiprocessors are outpacing improvements in the speed of disk hardware. Parallel disk I/O subsystems have been proposed as one way to close the gap between processor and disk speeds. In a previous paper we showed that prefetching and caching have the potential to deliver the performance benefits of parallel file systems to parallel applications. In this paper we describe experiments with practical prefetching policies that base decisions only on on-line reference history, and that can be implemented efficiently. We also test the ability of these policies across a range of architectural parameters.

Temporal Model Of An Optically Pumped Co-Doped Solid State Laser, T. G. Wangler, J. J. Swetits, A. M. Buoncristiani

Mathematics & Statistics Faculty Publications

Currently, research is being conducted on the optical properties of materials associated with the development of solid-state lasers in the 2 micron region. In support of this effort, a mathematical model describing the energy transfer in a holmium laser sensitized with thulium is developed. In this paper, we establish some qualitative properties of the solution of the model, such as non-negativity, boundedness, and integrability. A local stability analysis is then performed from which conditions for asymptotic stability are obtained. Finally, we report on our numerical analysis of the system and how it compares with experimental results.

Neural Network Diagnosis Of Malignant Melanoma From Color Images, Fikret ErçAl, C. Chawla, William V. Stoecker, Randy Hays Moss

Computer Science Technical Reports

Malignant melanoma is the deadliest form of all skin cancers. Approximately 32,000 new cases of malignant melanoma were diagnosed in 1991, with approximately 80 percent of patients expected to survive five years [1]. Fortunately, if detected early, even malignant melanoma may be treated successfully. Thus, in recent years, there has been a rising interest in the automated detection and diagnosis of skin cancer, particularly malignant melanoma [2]. In this paper, we present a novel neural network approach for the automated separation of melanoma from three other benign categories of tumors which exhibit melanoma-like characteristics. Our approach is based on devising …

Visual Inspection Algorithms For Printed Circuit Board Patterns A Survey, Madhav Moganti, Fikret ErçAl, Cihan H. Dagli

Computer Science Technical Reports

The importance of the inspection process has been magnified by the requirements of the modern manufacturing environment. In electronics mass-production manufacturing facilities, an attempt is often made to achieve 100 % quality assurance of all parts, subassemblies, and finished goods. A variety of approaches for automated visual inspection of printed circuits have been reported over the last two decades. In this survey, algorithms and techniques for the automated inspection of printed circuit boards are examined. A classification tree for these algorithms is presented and the algorithms are grouped according to this classification. This survey concentrates mainly on image analysis and …

Pseudobases In Direct Powers Of An Algebra, Paul Bankston

Mathematics, Statistics and Computer Science Faculty Research and Publications

A subset P of an abstract algebra A is a pseudobasis if every function from P into A extends uniquely to an endomorphism on A. A is called K-free has a pseudobasis of cardinality K; A is minimally free if A has a pseudobasis. (The 0-free algebras are "rigid" in the strong sense; the 1-free groups are always abelian, and are precisely the additive groups of E-rings.) Our interest here is in the existence of pseudobases in direct powers A^I of an algebra A. On the positive side, if A is a rigid …

Design And Implementation Of Fuzzy Logic Controllers. Thesis Final Report, 27 July 1992 - 1 January 1993, Osama A. Abihana, Oscar R. Gonzalez

Electrical & Computer Engineering Faculty Publications

The main objectives of our research are to present a self-contained overview of fuzzy sets and fuzzy logic, develop a methodology for control system design using fuzzy logic controllers, and to design and implement a fuzzy logic controller for a real system. We first present the fundamental concepts of fuzzy sets and fuzzy logic. Fuzzy sets and basic fuzzy operations are defined. In addition, for control systems, it is important to understand the concepts of linguistic values, term sets, fuzzy rule base, inference methods, and defuzzification methods. Second, we introduce a four-step fuzzy logic control system design procedure. The design …

Trimming And Closure Of Constrained Surfaces, Xiangping Chen, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

Modeling With A-Patches, Chandrajit L. Bajaj, Jindon Chen, Guoliang Xu

Department of Computer Science Technical Reports

No abstract provided.