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1993

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Articles 61 - 90 of 90

Full-Text Articles in Computer Engineering

The Programmers' Playground: I/O Abstraction For Heterogeneous Distributed Systems, Kenneth J. Goldman, Michael D. Anderson, Bala Swaminathan Jan 1993

The Programmers' Playground: I/O Abstraction For Heterogeneous Distributed Systems, Kenneth J. Goldman, Michael D. Anderson, Bala Swaminathan

All Computer Science and Engineering Research

I/O abstraction is offered as a new high-level approach to interprocess communication. Functional components of a concurrent system are written as encapsulated modules that act upon local data structures, some of which may be published for external use. Relationships among modules are specified by logical connections among their published data structures. Whenever a module updates published data, I/O takes place implicitly according to the configuration of logical connections. The Programmer's Playground, a software library and run-time system supporting I/O abstraction, is described. Design goals include high-level communication among programs written in multiple programming languages and the uniform treatment of discrete …


A Unified Model For Shared-Memory And Message-Passing Systems, Kenneth Goldman, Katherine Yelick Jan 1993

A Unified Model For Shared-Memory And Message-Passing Systems, Kenneth Goldman, Katherine Yelick

All Computer Science and Engineering Research

A unified model of distributed systems that accomodates both shared-memory and message-passing communication is proposed. An extension of the I/O automaton model of Lynch and Tuttle, the model provides a full range of types of atomic accesses to shared memory, from basic reads and writes to read-modify-write. In addition to supporting the specification and verification of shared memory algorithms, the unified model is particularly helpful for proving correspondences between atomic shared objects and invocation-response systems and for proving the correctness of systems that contain both message passing and shared memory (such as a network of shared-memory multiprocessors or a distributed …


Human And Machine Cognition Workshop Papers 1989, 1991, 1993, R. P. Loui Jan 1993

Human And Machine Cognition Workshop Papers 1989, 1991, 1993, R. P. Loui

All Computer Science and Engineering Research

No abstract provided.


A Design For Reasoning With Policies, Prrecedents And Rationales, Ronald P. Loui, Jeff Norman, Jon Olson, Andrew Merrill Jan 1993

A Design For Reasoning With Policies, Prrecedents And Rationales, Ronald P. Loui, Jeff Norman, Jon Olson, Andrew Merrill

All Computer Science and Engineering Research

No abstract provided.


Reasoning About Synchrony Illustrated On Three Models Of Concurrency, Gruia-Catalin Roman, Jerome Plun Jan 1993

Reasoning About Synchrony Illustrated On Three Models Of Concurrency, Gruia-Catalin Roman, Jerome Plun

All Computer Science and Engineering Research

This paper presents a model of concurrency (Dynamic Synchrony) whose distinctive feature is a novel formal treatment of synchronization. Synchrony is defined as the coordinated execution of two or more actions. The dynamic aspect comes from the fact that the definition of which actions must be executed synchronously can change freely during the execution of the program. This unique modeling capability comes with a UNITY-stype assertional logic that can be applied to program verification and derivation. This paper shows that the proposed proof logic can be used to verify programs expressed using other models of foncurrency without having to translate …


The Washington University Multimedia System, William D. Richard, Jerome R. Cox Jr., Brian Gottlieb, Ken Krieger Jan 1993

The Washington University Multimedia System, William D. Richard, Jerome R. Cox Jr., Brian Gottlieb, Ken Krieger

All Computer Science and Engineering Research

The Washington University Multimedia System (MMS) is a complete multimedia system capable of transmitting and receiving video, audio, and radiological images, in addition to normal network traffic, over the Washingon University broadband ATM network. The MMS 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 multimedia subsystems. The video sybsystem encodes and decodes JPEG compressed video using two hardware compression engines. The audio subsystem encodes and decodes CD-quality stereo audio. The high-speed radiological image subsystem reformats radiological image data transmitted by a dedicated …


A Fault Tolerant Connectionist Architecture For Construction Of Logic Proofs, Gadi Pinkas Jan 1993

A Fault Tolerant Connectionist Architecture For Construction Of Logic Proofs, Gadi Pinkas

All Computer Science and Engineering Research

This chapter considers the problems of expressing logic and constructing proofs in fault tolerant connectionist networks that are based on energy minimalism. Given a first-order-logic knowledge base and a bound k, a symmetric network is constructed (like a Boltzman machine or a Hopfield network) that searches for a proof for a given query. If a resolution-based proof of length no longer than k exists, then the global minima of the energy function that is associated with the network represent such proofs. If no proof exist then the global minima indicate the lack of a proof. The network that is generated …


Research Proposal: Preference Acquisition Through Reconciliation Of Inconsistencies, Nilesh L. Jain Jan 1993

Research Proposal: Preference Acquisition Through Reconciliation Of Inconsistencies, Nilesh L. Jain

All Computer Science and Engineering Research

The quality of performance of a decision-support system (or an expert system) is determined to a large extent by its underlying preference model (or knowledge base). The difficulties in preference and knowledge acquisition make them a major focus of current research in decision-support and expert systems. Researchers have used various concepts to develop promising acquisition techniques. One of the concepts used is knowledge maintenence where the knowledge base is changed in response to incorrect or inadequate performance by the expert system. This dissertation investigates a preference acquisition technique based on the reconciliation of inconsistencies between the preference model and the …


Objective Evaluation Of Radiation Treatment Plans, Nilesh L. Jain, Michael G. Kahn Jan 1993

Objective Evaluation Of Radiation Treatment Plans, Nilesh L. Jain, Michael G. Kahn

All Computer Science and Engineering Research

The evaluation of radiation treatment plans involves making trade-offs among doses delivered to the tumor volumes and nearby normal tissues. Evaluating state-of-the-art three-dimensional (3D) plans is a difficult task because of the huge amount of planning data that needs to be deciphered. Multiattribute utility theory provides a methodology for specifying trade-offs and selecting the optimal plan from many competing lans. Using multiattribute utility theory, we are developing a clinically meaningful objective plan-evaluation model for 3D radiation treatment plans. Our model incorporates three of the factors involved in radiation treatment evaluation - treatment preferences of the radiation oncologist, clinical condition of …


Supervised Competitive Learning With Backpropagation Network And Fuzzy Logic, Takayuki Dan Kimura, Thomas H. Fuller Jr., Ce Wang Jan 1993

Supervised Competitive Learning With Backpropagation Network And Fuzzy Logic, Takayuki Dan Kimura, Thomas H. Fuller Jr., Ce Wang

All Computer Science and Engineering Research

SCL assembles a set of learning modules into a supervised learning system to address the stability-plasticity dilemma. Each learning module acts as a similarity detector for a prototype, and includes prototype resetting (akin to that of ART) to respond to new prototypes. Here (Part I) we report SCL results using back-propagation networks as the learning modules. We used two feature extractors: about 30 energy-based features, and a combination of energy-based and graphical features (about 60). ACL recognized 96% (energy) and 99% (energy/graphical) of test digits, and 91% (energy) and 96% (energy/graphical) of test letters. In the accompanying paper (Part II), …


Teaching A Smarter Learner, Sally A. Goldman, H. David Mathias Jan 1993

Teaching A Smarter Learner, Sally A. Goldman, H. David Mathias

All Computer Science and Engineering Research

We introduce a formal model of teaching in which the teacher is tailored to a particular learner, yet the teaching protocol is designed so that no collusion is possible. Not surprisingly, such a model remedies the non-intuitive aspects of otehr models in which the teacher must successfully teach any consistent learner. We prove that any class that can be exactly identified by a deterministic polynomial-time algorithm with access to a very rich set of example-based queries is teachable by a computationally unbounded teacher and a polynomial-time learner. In addition, we present other general results relating this model of teaching to …


Improving The Speed Of A Distributed Checkpointing Algorithm, Sachin Garg, Kenneth F. Wong Jan 1993

Improving The Speed Of A Distributed Checkpointing Algorithm, Sachin Garg, Kenneth F. Wong

All Computer Science and Engineering Research

This paper shows how Koo and Toueg's distributed checkpointing algorithm can be modified so as to substantially reduce the average message volume. It attempts to avoid O(n{squared}) messages by using dependency knowledge to reduce the number of checkpoint request messages. Lemmas on consistency and termination are also included.


Trainrec: A System For Training Feedforward & Simple Recurrent Networks Efficiently And Correctly, Barry L. Kalman, Stan C. Kwasny Jan 1993

Trainrec: A System For Training Feedforward & Simple Recurrent Networks Efficiently And Correctly, Barry L. Kalman, Stan C. Kwasny

All Computer Science and Engineering Research

TRAINREC is a system for training feedforward and recurrent neural networks that incorporates several ideas. It uses the conjugate-gradient method which is demonstrably more efficient than traditional backward error propagation. We assume epoch-based training and derive a new error function having several desirable properties absent from the traditional sum-of-squared-error function. We argue for skip (shortcut) connections where appropriate and the preference for a sigmoidal yielding values over the [-1,1] interval. The input feature space is often over-analyzed, but by using singular value decomposition, input patterns can be conditioned for better learning often with a reduced number of input units. Recurrent …


A Characterization Of The Computational Power Of Rule-Based Visualization, Kenneth C. Cox, Gruia-Catalin Roman Jan 1993

A Characterization Of The Computational Power Of Rule-Based Visualization, Kenneth C. Cox, Gruia-Catalin Roman

All Computer Science and Engineering Research

Declarative visualization is a paradigm in which the process of visualization is treated as a mapping from some domain (typically a program) to an image. One means of declaring such mappings is through the use of rules which specify the relationship between the domain and the image. This paper examines the computational power of such rule-based mappings. Computational power is measure using three separate criteria. The first of these uses the Chomsky hierarchy, in which computational power is treated as string-acceptance; with this criterion we are able to show that certain rule-based models are equivalent in power to Turing machines. …


Logical Interference In Symmetric Connectionist Networks, Gadi Pinkas Jan 1993

Logical Interference In Symmetric Connectionist Networks, Gadi Pinkas

All Computer Science and Engineering Research

This work delineates the relation between logic and symmetric neural networks. The motivation is two-fold: 1) to study the capabilities and limitations of connectionist networks with respect to knowledge representatoin; and 2) to develop a new kind of inference negine that is expressive, massively parallel, capable of coping with nonmonotonic or noisy knowledge and capable of learning. The thesis shows that propositional logic can be implemented efficiently in networks where hidden units allow the representation of arbitrary constraints. An inference engine is constructed which can obtain its knowledge either by compiling symbolic rules or by learning them inductively from examples. …


A Comparison Study Of The Pen And The Mouse In Editing Graphic Diagrams, Ajay Apte, Takayuki Dan Kimura Jan 1993

A Comparison Study Of The Pen And The Mouse In Editing Graphic Diagrams, Ajay Apte, Takayuki Dan Kimura

All Computer Science and Engineering Research

We report the results of an experiment comparing the merits of the pen and the mouse as drawing devices. For this study a pen-based graphic diagram editor equipped with a shape recognition algorithm was developed on GO's PenPoint operating system. A commercially available drawing program on NeXT was used for mouse-based editing. Twelve CS students were chosen as subjects and asked to draw four different diagrams of similar complexity: two with a pen and the other two with a mouse. The diagrams are chosen from the categories of dataflow visual language, Petri nets, flowcharts, and state diagrams. The results indicate …


A Taxonomy Of Program Visualization Systems, Gruia-Catalin Roman, Kenneth C. Cox Jan 1993

A Taxonomy Of Program Visualization Systems, Gruia-Catalin Roman, Kenneth C. Cox

All Computer Science and Engineering Research

Program visualization may be viewed as a mapping from programs to graphical representations. This simple idea provides a formal framework for a new taxonomy of program visualization systems. The taxonomy is compared briefly against previous attempts to organize the program visualization field. The taxonomic principles and their motivation are explained in detail with reference to a number of existing systems, especially Balsa, Tango, and Pavane.


Asking Questions To Minimize Errors, Nader H. Bshouty, Sally A. Goldman, Thomas R. Hancock, Sleiman Matar Jan 1993

Asking Questions To Minimize Errors, Nader H. Bshouty, Sally A. Goldman, Thomas R. Hancock, Sleiman Matar

All Computer Science and Engineering Research

A number of efficient learning algorithms achieve exact identification of an unknown function from some clas using membership and equivalence queries. Using a standard transformation such algorithms can easily be converted to on-line learning algorithms that use membership queries. Under such a transformation the number of equivalence queries made by the query algorithm directly corresponds to the number of mistakes made by the on-line algorithm. In this paper we consider several of the natural classes known to be learnable in this setting, and investigate the minimum number of equivalence queries with accompanying counterexamples (or equivalently the minimum number of mistakes …


Dna Mapping Algorithms: Synchronized Double Digest Mapping, Jim Daues, Will Gillett Jan 1993

Dna Mapping Algorithms: Synchronized Double Digest Mapping, Jim Daues, Will Gillett

All Computer Science and Engineering Research

A technique called Synchronized Double Digest Mapping (SDDM) is presented; it combines classical Double Digest Mapping (DDM) and Multiple-Restriction-Enzyme Mapping (MREM). Classical DDM is a technique for determining the order of restriction fragments in a clone given three digestions of the clone: a digestion by enzyme1, a digestion by enzyme2, and a digestion by enzyme1 and enzyme2 combined. All algorithms for applying this technique are exponential (in the number of fragments present in the clone) in nature. MREM is an extension of classical high-resolution restriction-fragment mapping of a YAC or a genome, in which the overlaps among a set of …


Fril - A Fractal Intermediate Language, Ron Cytron, David Shields Jan 1993

Fril - A Fractal Intermediate Language, Ron Cytron, David Shields

All Computer Science and Engineering Research

This document describes the motivation, language description, and experience using FrIL, an intermediate language for a compiler's "middle-end." FrIL has subbessfully supported a two-semester compiler construction sequence, where the first semester included code generation from a C-like language and the second semester included advanced data flow analysis and program transformation.


The Pessimism Behind Optimistic Simulation, George Varghese, Roger D. Chamberlain, William E. Weihl Jan 1993

The Pessimism Behind Optimistic Simulation, George Varghese, Roger D. Chamberlain, William E. Weihl

All Computer Science and Engineering Research

In this paper we make an analogy between the time that storage must be maintained in an optimistic simulation and the blocking time in a conservative simulation. By exploring this analogy, we design two new Global Virtual Time (GVT) protocols for Time Warp systems. The first simple protocol is based on the null message scheme proposed for clock advancement in some conservative approaches; this yields what we call Local Guaranteed Time. Our main contribution is a second new protocol that is inspired by Misra's circulating marker scheme for deadlock recovery in conservative simulations, and appears to have advantages over previous …


The Washington University Multimedia Explorer, William D. Richard, Jerome R. Cox Jr., A. Maynard Engebretson, Jason Fritts, Craig Horn Jan 1993

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 …


Rule-Maker's And Rule-Follower's Meaning, R. P. Loui Jan 1993

Rule-Maker's And Rule-Follower's Meaning, R. P. Loui

All Computer Science and Engineering Research

No abstract provided.


Visual Process Language: An Environment That Enhances Inventiveness In The System Development Process -- A Theoretical Perspective, Wita Wojtkowski, Waclaw G. Wojtkowski Jan 1993

Visual Process Language: An Environment That Enhances Inventiveness In The System Development Process -- A Theoretical Perspective, Wita Wojtkowski, Waclaw G. Wojtkowski

IT and Supply Chain Management Faculty Publications and Presentations

This paper provides a theoretical perspective on the effect of computer support on creativity. The assertion is made that artifacts of IS do not substantially differ from those of art and science, and that the creative processes leading to the artifacts are similar. It further proposes that the use of newly available computer technology, specifically, the Visual Process Language (VPL) will have much to offer in terms of augmenting creativity when constructing IS artfacts. We postulate that VPL assists the first insight, preparation and illumination steps of the creative process, and that both Association/Images and Progressive Abstraction techniques are embedded …


Computer Model For Predicting Aids Among Intravenous Drug Users, Daniel Berleant, R. Ron Goforth, Jun Yuan Jan 1993

Computer Model For Predicting Aids Among Intravenous Drug Users, Daniel Berleant, R. Ron Goforth, Jun Yuan

Journal of the Arkansas Academy of Science

Intravenous drug abuse (IVDA) is an important cause of HIV transmission. Computer simulation is one way to understand and predict the spread of HIV infection among IVDAs. We design and simulate HIV infection among IVDAs and the impact of AIDS on this community, and thereby predict future IVDA population, HIV levels, AIDS levels, and AIDS deaths in this group. The HIV to AIDS, and AIDS to Death latencies are described by probability density functions (PDFs) in this model. Factors such as the recruit, quit, and normal death rate of IVDAs, are considered, as well as the infection and removal rates …


Graduate Catalog Center For Computer And Information Sciences, Nova Southeastern University Jan 1993

Graduate Catalog Center For Computer And Information Sciences, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.


Graduate Catalog Center For Computer And Information Sciences 1993-1994 Catalog, Nova Southeastern University Jan 1993

Graduate Catalog Center For Computer And Information Sciences 1993-1994 Catalog, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.


A Study Of Dynamic Optimization Techniques: Lessons And Directions In Kernel Design, Calton Pu, Jonathan Walpole Jan 1993

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 …


Observation Of The Charmed Baryon C+ And Measurement Of The Isospin Mass Splittings Of The C, Crawford, G.; Et Al., M. Thulasidas Jan 1993

Observation Of The Charmed Baryon C+ And Measurement Of The Isospin Mass Splittings Of The C, Crawford, G.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.


Scanner To Printer Color Calibration (Title Translated From French), Cécile Péraire Dec 1992

Scanner To Printer Color Calibration (Title Translated From French), Cécile Péraire

Cécile Péraire

No abstract provided.