Physical Sciences and Mathematics Commons^™

Resource Access Control For An Internet User Agent, Nataraj Nagaratnam, Steven B. Byrne

Electrical Engineering and Computer Science - All Scholarship

The rapid increase in the Internet's connectivity has lead to proportional increase in the development of Web-based applications. Usage of downloadable content has proved effective in a number of emerging applications including electronic commerce, software components on-demand, and collaborative systems. In all these cases, Internet user agents (like browsers, tuners) are widely used by the clients to utilize and execute such downloadable content. With this new technology of using downloadable content comes the problem of the downloaded content obtaining unauthorized access to the client's resources. In effect, granting a hostile remote principal the requested access to client's resources may lead …

The Software Architecture Of A Virtual Distributed Computing Environment, Haluk Topcuoglu, Salim Hariri, Wojtek Furmanski, Jon Valente

Electrical Engineering and Computer Science - All Scholarship

The requirements of grand challenge problems and the deployment of gigabit networks makes the network computing framework an attractive and cost effective computing environment with which to interconnect geographically distributed processing and storage resources. Our project, Virtual Distributed Computing Environment (VDCE), provides a problem-solving environment for high-performance distributed computing over wide area networks. VDCE delivers well-defined library functions that relieve end-users of tedious task implementations and also support reusability. In this paper we present the conceptual design of VDCE software architecture, which is defined in three modules: a) the Application Editor, a user-friendly application development environment that generates the Application …

A Compiler Algorithm For Optimizing Locality In Loop Nests, Mahmut Kandemir, J. Ramanujam, Alok Choudhary

Electrical Engineering and Computer Science - All Scholarship

This paper describes an algorithm to optimize cache locality in scientific codes on uniprocessor and multiprocessor machines. A distinctive characteristic of our algorithm is that it considers loop and data layout transformations in a unified framework. We illustrate through examples that our approach is very effective at reducing cache misses and tile size sensitivity of blocked loop nests; and can optimize nests for which optimization techniques based on loop transformations alone are not successful. An important special case is the one in which data layouts of some arrays are fixed and cannot be changed. We show how our algorithm can …

Parallel Domain Decomposition And Load Balancing Using Space-Filling Curves, Srinivas Aluru, Faith E. Sevilgen

Electrical Engineering and Computer Science - All Scholarship

Partitioning techniques based on space-filling curves have received much recent attention due to their low running time and good load balance characteristics. The basic idea underlying these methods is to order the multidimensional data according to a space-filling curve and partition the resulting one-dimensional order. However, space-filling curves are defined for points that lie on a uniform grid of a particular resolution. It is typically assumed that the coordinates of the points are representable using a fixed number of bits, and the run-times of the algorithms depend upon the number of bits used. In this paper, we present a simple …

An Efficient K-Means Clustering Algorithm, Khaled Alsabti, Sanjay Ranka, Vineet Singh

Electrical Engineering and Computer Science - All Scholarship

In this paper, we present a novel algorithm for performing k-means clustering. It organizes all the patterns in a k-d tree structure such that one can find all the patterns which are closest to a given prototype efficiently. The main intuition behind our approach is as follows. All the prototypes are potential candidates for the closest prototype at the root level. However, for the children of the root node, we may be able to prune the candidate set by using simple geometrical constraints. This approach can be applied recursively until the size of the candidate set is one for each …

Selective Crossover: Towards Fitter Offspring, Chilukuri K. Mohan

Electrical Engineering and Computer Science - All Scholarship

A new general-purpose crossover operator is proposed. The representation of a candidate solution is slightly perturbed, and the ensuing changes in fitness are calculated. Such fitness changes (for parents) are used in constructing the offspring resulting from crossover. Experiments with several sets of problems demonstrate that this approach leads to rapid increases in average and best fitness, and performs much better than traditional general-purpose crossover operators.

A Global Computing Environment For Networked Resources, Haluk Topcuoglu, Salim Hariri

Electrical Engineering and Computer Science - All Scholarship

Current advances in high-speed networks and WWW technologies have made network computing a cost-effective, high-performance computing alternative. New software tools are being developed to utilize efficiently the network computing environment. Our project, called Virtual Distributed Computing Environment (VDCE), is a high-performance computing environment that allows users to write and evaluate networked applications for different hardware and software configurations using a web interface. In this paper we present the software architecture of VDCE by emphasizing application development and specification, scheduling, and execution/runtime aspects.

Simulated Annealing And Genetic Algorithms For Partial Shape Matching, Ender Ozcan, Chilukuri K. Mohan

Electrical Engineering and Computer Science - All Scholarship

Partial shape matching may be viewed as an optimization problem, to be solved using methods such as simulated annealing (SA) and genetic algorithms (GAs). We apply and compare both these methods for matching input shapes with model shapes described in terms of features such as line segments and angles. The quality of matching is gauged using a measure derived from attributed shape grammars [10, 11]. Current results show that both SA and GA succeed in the shape matching task; the GA is faster and yields the global optimum more often than the versions of SA implemented.

Standardization Of A Communication Middleware For High-Performance Real-Time Systems, Arkady Kanevsky, Anthony Skjellum, Jerrell Watts

Electrical Engineering and Computer Science - All Scholarship

The last several years saw an emergence of standardization activities for real-time systems including standardization of operating systems (series of POSIX standards [1]), of communication for distributed (POSIX.21 [10]) and parallel systems (MPI/RT [5]) and real-time object management (realtime CORBA [9]). This article describes the ongoing standardization work and implementation of communication middleware for high performance real-time computing. The real-time message passing interface (MPI/RT) advances the non-real-time high-performance communication standard Message Passing Interface Standard (MPI), emphasizing changes that enable and support real-time communication, and is targeted for embedded, fault-tolerant and other real-time systems. MPI/RT is the only communication middleware layer …

Topology And Logic Programming Semantics, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Logic programming employs logic as a programming language. Thus a logic program consists of a set of clauses of a certain form most often a subset of the clauses of first order logic viewed as axioms. Computation in this paradigm is deduction from these axioms via some interpreter.

Logic programming semantics is concerned with background theory for logic programming. It tries to provide models for logic programs to give them their intended meaning and to connect them with practically implementable interpreters.

Multiprocessor Out-Of-Core Ffts With Distributed Memory And Parallel Disks, Thomas H. Cormen, Jake Wegmann, David M. Nicol

Computer Science Technical Reports

This paper extends an earlier out-of-core Fast Fourier Transform (FFT) method for a uniprocessor with the Parallel Disk Model (PDM) to use multiple processors. Four out-of-core multiprocessor methods are examined. Operationally, these methods differ in the size of "mini-butterfly" computed in memory and how the data are organized on the disks and in the distributed memory of the multiprocessor. The methods also perform differing amounts of I/O and communication. Two of them have the remarkable property that even though they are computing the FFT on a multiprocessor, all interprocessor communication occurs outside the mini-butterfly computations. Performance results on a small …

A Proposed Solution For Word-Recognition Deficit In The Computer Environment, Hyacinth Williams

CCE Theses and Dissertations

Most college students with reading disabilities have difficulty with word recognition. The purpose of this study was to use an investigator-made cue word list to increase low word recognition skills among college students while creating slides for a university curriculum using a simple presentation tool. The investigator randomly divided fourteen subjects into two groups. One group received the treatment and the other did not. Subjects received fifty minutes to complete a five-slide presentation. The investigator used four different data collection processes for data collection. Beyond this, the investigator presented the results using rank correlation. Results from this study indicated that …

Financial Prediction And Trading Strategies Using Neurofuzzy Approaches, K. N. Pantazopoulos, L. H. Tsoukalas, N. G. Bourbakis, M. J. Brün, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.

Computing Volumes Of Solids Enclosed By Recursive Subdivision Surfaces, Jörg Peters, Ahmad Nasri

Department of Computer Science Technical Reports

No abstract provided.

Future Scientific Software Systems, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Videotext Database System, Haitao Jiang, Danilo Montesi, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.

Computing Moments Of Piecewise Polynomial Surfaces, Carlos Gonzalez-Ochoa, Scott Mccammon, Jörg Peters

Department of Computer Science Technical Reports

No abstract provided.

Performance Analysis And Visualization Tools For Parallel Computing, K. N. Pantazopoulos, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.

Semantic Analysis Of The Postscript Page Description Language, Ben Knuth

Honors Theses, 1963-2015

The Postscript page description language is a functional programming language. Central to the effective use of the language are the functional properties of delayed evaluation and referential transparency. Postscript performs all of its operations via distinct, multiple stacks which stores function binding lists, function parameters, and function code. By way of these stacks, Postscript creates dynamic computational states which leads identical expressions to evaluate to different results. This hints towards the polymorphic quality of an object-oriented language, even though it contradicts the functional precept of manifest interfaces thereby introducing a nonorthogonality. One other streak of object-orientation that shows up in …

How Secure Transactions Are Achieved On The Internet Using Ssl: An Honors Presentation Of Internet Security Practices And Protocols, Julie Klinefelter

Honors Theses, 1963-2015

The goal of this project is to research and present the security protocol "Secure Sockets Layer" or as it is more commonly referred to, "SSL." SSL is one of the main encryption techniques used by the internet industry to help ensure the secure transfer of information across the internet. It is one of the main encryption techniques currently under review by Internet Engineering Task Force. SSL is comprised of a strict protocol that initiates a secure "session" between two computing devices. The session is established above the transport level (on the OSI model) and encrypts from the session up. Therefore …

Examining Locally Varying Weights For Nearest Neighbor Algorithms, Nicholas Howe, Claire Cardie

Computer Science: Faculty Publications

Previous work on feature weighting for case-based learning algorithms has tended to use either global weights or weights that vary over extremely local regions of the case space. This paper examines the use of coarsely local weighting schemes, where feature weights are allowed to vary but are identical for groups or clusters of cases. We present a new technique, called class distribution weighting (CDW), that allows weights to vary at the class level. We further extend CDW into a family of related techniques that exhibit varying degrees of locality, from global to local. The class distribution techniques are then applied …

Computer-Aided Mechanical Assembly Design Using Configuration Spaces, Leo Joskowicz, Elisha Sacks

Department of Computer Science Technical Reports

No abstract provided.

Interface Relaxation Methods For Elliptic Differential Equations, John R. Rice, P. Tsompanopoulou, E. Vavalis

Department of Computer Science Technical Reports

No abstract provided.

Adaptive Multicast Routing In Wormhole Networks, Ran Libeskind-Hadas, Tom Hehre '96, Andrew Hutchings '98, Mark Reyes '98, Kevin Watkins '97

All HMC Faculty Publications and Research

Multicast communication has applications in a number of fundamental operations in parallel computing. An effective multicast routing algorithm must be free from both livelock and deadlock while minimizing communication latency. We describe two classes of multicast wormhole routing algorithms that employ the multi-destination wormhole hardware mechanism proposed by Lin et al. [12] and Panda et al. [17]. Specific examples of these classes of algorithms are described and experimental results suggests that such algorithms enjoy low communication latencies across a range of network loads.

Microlanguages For Operating System Specialization, Calton Pu, Andrew P. Black, Crispin Cowan, Jonathan Walpole, Charles Consel

Computer Science Faculty Publications and Presentations

Specialization is a technique that has the potential to provide operating system clients with the performance and functionality that they need, while still retaining the advantages of a simple generic code base for the operating system maintainer. However, at present the specialization process is labor-intensive and requires the knowledge of an expert in the domain of application behavior. In order to realize the full advantages of specialization, we believe that the process must be automated. This means building tools for specialization, and also making the domain knowledge explicit in some form or other. A specialization toolkit has been developed jointly …

The Recursive Multi-Threaded Software Life-Cycle, Scott James Simon

Theses Digitization Project

No abstract provided.

International Student Services Opportunity Database (Issodb), Sailaja Malireddy

Theses Digitization Project

No abstract provided.

Response Surface Methodology: An Analytical Method For Locating Migrated Contaminant Sources, Orlando J. Dona Jr.

Theses and Dissertations

The use and storage of hazardous chemicals at U.S. military facilities often adversely affect the groundwater when contaminants infiltrate the subsurface as a result of leaks and accidental spills. These contaminants, if not located and remediated in a relatively short time, may move and settle unpredictably, essentially creating a source some distance from the original leak or spill. An example of this phenomenon is found with migrating dense nonaqueous phase liquid (DNAPL) contaminants. Although various methods for estimating the present day locations of these migrated contaminants are in use, accurately pinpointing the source of contaminants remains a difficult problem in …

Review Of Personal Identification Systems, J. M. Cross

Research outputs pre 2011

The growth of the use of biometric personal identification systems has been relatively steady over the last 20 years. The expected biometric revolution which was forecast since the mid 1970's has not yet occurred. The main factor for lower than expected growth has been the cost and user acceptance of the systems. During the last few years, however, a new generation of more reliable, less expensive and better designed biometric devices have come onto the market. This combined with the anticipated expansion of new reliable, user friendly inexpensive systems provides a signal that the revolution is about to begin. This …

Timestamp-Based Approach For The Detection And Resolution Of Mutual Conflicts In Distributed Systems, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

We present a timestamp based algorithm for the detection of both write-write and read-write conflicts for a single file in distributed systems during network partitions. Our algorithm allows operations to occur in different network partitions simultaneously. When the sites from different partitions merge, the algorithm detects and resolves both read-write and write-write conflicts without taking into account the semantics of the transactions. Once the conflicts have been detected some reconciliation steps for the resolution of conflicts have also been proposed. Our algorithm will be useful in real-time systems where timeliness of operations is more important than response time (delayed commit)