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Full-Text Articles in Physical Sciences and Mathematics

Powerfaids: Building A Road To Financial Aid Efficiency, Lauri Nichols '96 Apr 1996

Powerfaids: Building A Road To Financial Aid Efficiency, Lauri Nichols '96

Honors Projects

To most students, the Financial Aid office is a small room in the basement of Holmes Hall where they are occasionally sent to sign over a paper or two. It has something to do with money, and every so often, these students get something in the mail that tells them just how much it's going to cost them to continue their education here at Illinois Wesleyan. They know that papers are filled out, usually by their parents, and then in a couple of months, a figure jumps out of nowhere and becomes "Your Financial Aid Package."


The Expected Lifetime Of Single-Address-Space Operating Systems, David Kotz, Preston Crow Apr 1996

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. To simplify address-space management, 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 the design of appropriate address-space management policies. In this paper, we present the results of extensive kernel-level tracing of the workstations on our campus, and discuss the implications for …


Compressing Semi-Structured Text Using Hierarchical Phrase Identifications, Dan R. Olsen Jr., Craig G. Nevill-Manning, Ian H. Witten Apr 1996

Compressing Semi-Structured Text Using Hierarchical Phrase Identifications, Dan R. Olsen Jr., Craig G. Nevill-Manning, Ian H. Witten

Faculty Publications

The structure of this paper is as follows. We begin by identifying some characteristics of semi-structured text that have special relevance to data compression. We then give a brief account of a particular large textual database, and describe a compression scheme that exploits its structure. In addition to providing compression, the system gives some insight into the structure of the database. Finally we show how the hierarchical grammar can be generalized, first manually and then automatically, to yield further improvements in compression performance.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 4, April 1996, College Of Engineering And Computer Science, Wright State University Apr 1996

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 4, April 1996, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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


Parametric Kinematic Tolerance Analysis Of Planar Mechanisms, Elisha Sacks, Leo Joskowicz Apr 1996

Parametric Kinematic Tolerance Analysis Of Planar Mechanisms, Elisha Sacks, Leo Joskowicz

Department of Computer Science Technical Reports

No abstract provided.


Tonitza A Graphics Package For Structural Biology User's Guide, Ioana Maria Martin, Dan C. Marinescu Apr 1996

Tonitza A Graphics Package For Structural Biology User's Guide, Ioana Maria Martin, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.


An Improved Hypercube Bound For Multisearching And Its Applications, Mikhail J. Atallah Apr 1996

An Improved Hypercube Bound For Multisearching And Its Applications, Mikhail J. Atallah

Department of Computer Science Technical Reports

No abstract provided.


Variable Step Size Lms Adaptive Filters With Delayed Coefficient Updating, Guixian Xu Apr 1996

Variable Step Size Lms Adaptive Filters With Delayed Coefficient Updating, Guixian Xu

Electrical & Computer Engineering Theses & Dissertations

A new approach to delayed LMS adaptive filtering is presented, which uses a variable step size for coefficient updating to increase convergence speed and improve tracking characteristics. The new algorithm, called delayed variable step size LMS (DVLMS), is explained, analyzed, and simulated to experimentally determine performance characteristics. Three different strategies for adjusting the step size are examined, and their performance is compared. Also, simulation results are presented to show that the proposed DVLMS systems provide faster convergence and lower mis-adjustment than previously proposed DLMS systems.


Low-Degree Spanning Trees Of Small Weight, Samir Khuller, Balaji Raghavachari, Neal Young Apr 1996

Low-Degree Spanning Trees Of Small Weight, Samir Khuller, Balaji Raghavachari, Neal Young

Dartmouth Scholarship

Given n points in the plane, the degree-K spanning-tree problem asks for a spanning tree of minimum weight in which the degree of each vertex is at most K. This paper addresses the problem of computing low-weight degree-K spanning trees for $K > 2$. It is shown that for an arbitrary collection of n points in the plane, there exists a spanning tree of degree 3 whose weight is at most 1.5 times the weight of a minimum spanning tree. It is shown that there exists a spanning tree of degree 4 whose weight is at most 1.25 times …


Speech Feature Computation For Visual Speech Articulation Training, Stefan Auberg Apr 1996

Speech Feature Computation For Visual Speech Articulation Training, Stefan Auberg

Electrical & Computer Engineering Theses & Dissertations

A new version of the Visual Speech Articulation Training Aid was implemented which provides real-time visual feedback for speech articulation training. This version was migrated to a Windows Multimedia PC from a previous version which used a Personal Computer (PC) system and additional specialized and expensive custom hardware. This new version will make the system more available to schools and private users. A new method was developed for computing spectral/temporal features which characterize the speech sounds. In addition to the typical frame-based spectral analysis parameters, the new method represents temporal changes of the spectrum with a small number of features. …


Adaptive Integration Of Audio And Visual Information Using Discrete And Semi-Continuous Hidden Markov Models In Audiovisual Automatic Speech Recognition, Qin Su Apr 1996

Adaptive Integration Of Audio And Visual Information Using Discrete And Semi-Continuous Hidden Markov Models In Audiovisual Automatic Speech Recognition, Qin Su

Electrical & Computer Engineering Theses & Dissertations

An audiovisual semi-continuous hidden Markov model (HMM)-based Automatic Speech Recognition (ASR) system and an improved method of integrating audio and visual information in an audiovisual discrete HMM-based ASR system are investigated.

In the audiovisual discrete HMM, an adaptive integration formulation is employed, which incorporates the integration into the HMM at a pre-categorical stage. A visual weighting parameter is determined automatically, which allows the relative contribution of audio and visual information to be adjusted adaptively. Using an adaptive weight, the accuracy increased by 13% compared to the same model with no adaptive weight.

The semi-continuous HMM is a class of models …


Visibility-Related Problems On Parallel Computational Models, Himabindu Gurla Apr 1996

Visibility-Related Problems On Parallel Computational Models, Himabindu Gurla

Computer Science Theses & Dissertations

Visibility-related problems find applications in seemingly unrelated and diverse fields such as computer graphics, scene analysis, robotics and VLSI design. While there are common threads running through these problems, most existing solutions do not exploit these commonalities. With this in mind, this thesis identifies these common threads and provides a unified approach to solve these problems and develops solutions that can be viewed as template algorithms for an abstract computational model. A template algorithm provides an architecture independent solution for a problem, from which solutions can be generated for diverse computational models. In particular, the template algorithms presented in this …


Scheduling Processors For Distributed, Critical, Real-Time Systems, Hari K. Narasimhamurthy Apr 1996

Scheduling Processors For Distributed, Critical, Real-Time Systems, Hari K. Narasimhamurthy

Electrical & Computer Engineering Theses & Dissertations

The development of a procedure to obtain cyclo-static schedules for distributed, critical real-time applications is presented in this thesis. The applications considered in this thesis are characterized by hard deadlines and periodic inputs. The applica­ tions are described by a data flow graph model which guarantees performance. Given the data flow graph representation, processors are scheduled to complete tasks as specified in the representation. The scheduling technique separates the scheduling of tasks in time and the assignment of processors to tasks. While different criteria exist for task scheduling, a schedule which minimizes latency and maximizes throughput is used in this …


File-Access Characteristics Of Parallel Scientific Workloads, Nils Nieuwejaar, David Kotz, Apratim Purakayastha, Carla Schlatter Ellis, Michael Best Mar 1996

File-Access Characteristics Of Parallel Scientific Workloads, Nils Nieuwejaar, David Kotz, Apratim Purakayastha, Carla Schlatter Ellis, Michael Best

Computer Science Technical Reports

Phenomenal improvements in the computational performance of multiprocessors have not been matched by comparable gains in I/O system performance. This imbalance has resulted in I/O becoming a significant bottleneck for many scientific applications. One key to overcoming this bottleneck is improving the performance of parallel file systems.

The design of a high-performance parallel file system requires a comprehensive understanding of the expected workload. Unfortunately, until recently, no general workload studies of parallel file systems have been conducted. The goal of the CHARISMA project was to remedy this problem by characterizing the behavior of several production workloads, on different machines, at …


A Queuing Analysis Of Bandwidth Allocation Schemes For Compressed Video, Saurab Nog, Carl J. Beckmann Mar 1996

A Queuing Analysis Of Bandwidth Allocation Schemes For Compressed Video, Saurab Nog, Carl J. Beckmann

Computer Science Technical Reports

Video and audio compression techniques allow continuous media streams to be transmitted at bit rates that are a function of the delivered quality of service. Digital networks will be increasingly used for the transmission of such continuous media streams. This paper describes an admission control policy in which the quality of service is negotiated at stream initiation, and is a function of both the desired quality of service and the available bandwidth resources. The advantage of this approach is the ability to robustly service large numbers of users, while providing increased quality of service during low usage periods. Several simple …


The Expected Lifetime Of "Single-Address-Space" Operating Systems, David Kotz, Preston Crow Mar 1996

The Expected Lifetime Of "Single-Address-Space" Operating Systems, David Kotz, Preston Crow

Computer Science Technical Reports

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 …


Categorization Of Programs Using Neural Networks, Franz J. Kurfess, Lonnie R. Welch Mar 1996

Categorization Of Programs Using Neural Networks, Franz J. Kurfess, Lonnie R. Welch

Computer Science and Software Engineering

This paper describes some experiments based on the use of neural networks for assistance in the quality assessment of programs, especially in connection with the reengineering of legacy systems. We use Kohonen networks, or self-organizing maps, for the categorization of programs: programs with similar features are grouped together in a two-dimensional neighbourhood, whereas dissimilar programs are located far apart. Backpropagation networks are used for generalization purposes: based on a set of example programs whose relevant aspects have already been assessed, we would like to obtain an extrapolation of these assessments to new programs. The basis for these investigation is an …


An Rpc Mechanism For Transportable Agents, Saurab Nog, Sumit Chawla, David Kotz Mar 1996

An Rpc Mechanism For Transportable Agents, Saurab Nog, Sumit Chawla, David Kotz

Computer Science Technical Reports

Transportable agents are autonomous programs that migrate from machine to machine, performing complex processing at each step to satisfy client requests. As part of their duties agents often need to communicate with other agents. We propose to use remote procedure call (RPC) along with a flexible interface definition language (IDL), to add structure to inter-agent communication. The real power of our Agent RPC comes from a client-server binding mechanism based on flexible IDL matching and from support for multiple simultaneous bindings. Our agents are programmed in Agent Tcl; we describe how the Tcl implementation made RPC particularly easy to implement. …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 3, March 1996, College Of Engineering And Computer Science, Wright State University Mar 1996

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 3, March 1996, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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


Stochastic Approximation Methods For Systems Over An Infinite Horizon, Harold J. Kushner, Felisa Vázquez-Abad Mar 1996

Stochastic Approximation Methods For Systems Over An Infinite Horizon, Harold J. Kushner, Felisa Vázquez-Abad

Publications and Research

The paper develops efficient and general stochastic approximation (SA) methods for improving the operation of parametrized systems of either the continuous- or discrete-event dynamical systems types and which are of interest over a long time period. For example, one might wish to optimize or improve the stationary (or average cost per unit time) performance by adjusting the systems parameters. The number of applications and the associated literature are increasing at a rapid rate. This is partly due to the increasing activity in computing pathwise derivatives and adapting them to the average-cost problem. Although the original motivation and the examples come …


A Generic Intelligent Architecture For Computer-Aided Training Of Procedural Knowledge, Freeman A. Kilpatrick Jr. Mar 1996

A Generic Intelligent Architecture For Computer-Aided Training Of Procedural Knowledge, Freeman A. Kilpatrick Jr.

Theses and Dissertations

Intelligent Tutoring System (ITS) development is a knowledge-intensive task, suffering from the same knowledge acquisition bottleneck that plagues most Artificial Intelligence (AI) systems. This research presents an architecture that requires knowledge only in the form of a shallow knowledge base and a simulation to produce a training system. The knowledge base provides the basic procedural knowledge while the simulation provides context. The remainder of the knowledge required for training is learned through the interaction of these components in a state-space scenario exploration process and inductive machine learning. These knowledge components are used only at the interface level, allowing the internal …


Generalized Hidden Filter Markov Models Applied To Speaker Recognition, John M. Colombi Mar 1996

Generalized Hidden Filter Markov Models Applied To Speaker Recognition, John M. Colombi

Theses and Dissertations

Classification of time series has wide Air Force, DoD and commercial interest, from automatic target recognition systems on munitions to recognition of speakers in diverse environments. The ability to effectively model the temporal information contained in a sequence is of paramount importance. Toward this goal, this research develops theoretical extensions to a class of stochastic models and demonstrates their effectiveness on the problem of text-independent (language constrained) speaker recognition. Specifically within the hidden Markov model architecture, additional constraints are implemented which better incorporate observation correlations and context, where standard approaches fail. Two methods of modeling correlations are developed, and their …


Teaching Ethical Issues In Computer Science: What Worked And What Didn't, Kay G. Schulze, Frances Grodzinsky Mar 1996

Teaching Ethical Issues In Computer Science: What Worked And What Didn't, Kay G. Schulze, Frances Grodzinsky

School of Computer Science & Engineering Faculty Publications

It is the role of computer science educators to ensure that students have a firm foundation in the social and ethical issues of the discipline.


A System For Structured Management Of Hypermedia Resources For The World Wide Web, Kevin L. Marlowe Mar 1996

A System For Structured Management Of Hypermedia Resources For The World Wide Web, Kevin L. Marlowe

Computer Science Theses & Dissertations

The World Wide Web (WWW) is arguably the preferred method for disseminating information across the Internet. Most of the work to support the advancement of WWW technology has focused on servers used in storing and retrieving information, browsers for viewing this information, and editors or filters for creating the information.

One area which has received little attention is that of actually managing this information at the local host. This thesis describes the development of a means for organizing local data prior to its publishing on the WWW, a method for gathering local pages together and preparing them for distribution, and …


Non-Traditional Techniques In Teaching Science For General Students, Gary Lewis, Ben Golden, Gail Schiffer, Diane Willey Feb 1996

Non-Traditional Techniques In Teaching Science For General Students, Gary Lewis, Ben Golden, Gail Schiffer, Diane Willey

Gary C. Lewis

No abstract provided.


World Wide Web, Netscape, And Simple Html Coding: What Use Do They Have In The Classroom?, C. Claiborne, Sonya Shepherd Feb 1996

World Wide Web, Netscape, And Simple Html Coding: What Use Do They Have In The Classroom?, C. Claiborne, Sonya Shepherd

Sonya S. Gaither

No abstract provided.


On The Interaction Of Object-Oriented Design Patterns And Programming Languages, Gerald Baumgartner, Konstantin Läufer, Vincent F. Russo Feb 1996

On The Interaction Of Object-Oriented Design Patterns And Programming Languages, Gerald Baumgartner, Konstantin Läufer, Vincent F. Russo

Computer Science: Faculty Publications and Other Works

Design patterns are distilled from many real systems to catalog common programming practice. However, some object-oriented design patterns are distorted or overly complicated because of the lack of supporting programming language constructs or mechanisms. For this paper, we have analyzed several published design patterns looking for idiomatic ways of working around constraints of the implementation language. From this analysis, we lay a groundwork of general-purpose language constructs and mechanisms that, if provided by a statically typed, object-oriented language, would better support the implementation of design patterns and, transitively, benefit the construction of many real systems. In particular, our catalog of …


R-By-C Crozzle: An Np-Hard Problem, Michelle Gower, Ralph W. Wilkerson Feb 1996

R-By-C Crozzle: An Np-Hard Problem, Michelle Gower, Ralph W. Wilkerson

Computer Science Faculty Research & Creative Works

In an Australian Magazine, a Monetary Prize is Awarded to the Person with the Best Answer to a Word Puzzle Called a Crozzle. the Placement of Words into a Ten by Fifteen Grid Obtaining the Highest Score is the Best Answer. Various Search Techniques Have Been Employed to Solve This Problem, Yet No One Has Shown Whether There is a Polynomial-Time Algorithm to Find the Best Crozzle. This Paper Creates a Similar Word Puzzle, Called R-By-C Crozzle, by Lifting the Constraint on the Grid Size. R-By-C Crozzle is Not in NP, But There Exists a Polynomial Reduction to It from …


Near Perfect Hash Table For Image Databases, Sanjiv K. Bhatia, Chaman Sabharwal Feb 1996

Near Perfect Hash Table For Image Databases, Sanjiv K. Bhatia, Chaman Sabharwal

Computer Science Faculty Research & Creative Works

In image database systems, a perfect hash table can be used to enhance the efficiency and effectiveness of the image retrieval process. In our earlier work, we have proposed heuristic algorithms to compute the minimal perfect hash table from symbolic picture objects. The hash table thus computed cannot be modified easily, limiting its application to fixed databases like the ones on CD-ROMs. In this paper, we propose a new data structure to allow for insertion and deletion in the hash table. The new data structure, the near-perfect hash table, allows a limited number of collisions on some of the hash …


Data Parallel Implementation Of Surface-To-Surface Intersection, Terence M. Burke, Chaman Sabharwal Feb 1996

Data Parallel Implementation Of Surface-To-Surface Intersection, Terence M. Burke, Chaman Sabharwal

Computer Science Faculty Research & Creative Works

The sequential surface-to-surface intersection algorithm has been extensively studied in the past decade. With the advent of parallel processing machines, it is desirable to parallelize this algorithm to gain extra computation speed for real time applications. An earlier attempt to parallelize this algorithm was on shared memory parallel computer due to the highly shared model of data structure [Chang 1991). A shared memory machine is not available at every location. Instead, we have implemented it on distributed parallel computer iPSC/860 with 32 processors. The initial development was done using PVM software in heterogeneous environment consisting of Sun workstations and 486's …