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Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

1998

Syracuse University

Electrical Engineering and Computer Science - All Scholarship

Articles 1 - 16 of 16

Full-Text Articles in Physical Sciences and Mathematics

Verification And Validation Of Simulation Models, Robert G. Sargent Jan 1998

Verification And Validation Of Simulation Models, Robert G. Sargent

Electrical Engineering and Computer Science - All Scholarship

This paper discusses verification and validation of simulation models. The different approaches to deciding model validity are presented; how model verification and validation relate to the model development process are discussed; various validation techniques are defined; conceptual model validity, model verification, operational validity, and data validity are described; ways to document results are given; and a recommended procedure is presented.

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A Global Communication Optimization Technique Based On Data-Flow Analysis And Linear Algebra, Mahmut Kandemir, P. Banerjee, Alok Choudhary, J. Ramanujam Jan 1998

A Global Communication Optimization Technique Based On Data-Flow Analysis And Linear Algebra, Mahmut Kandemir, P. Banerjee, Alok Choudhary, J. Ramanujam

Electrical Engineering and Computer Science - All Scholarship

Reducing communication overhead is extremely important in distributed-memory message-passing architectures. In this paper, we present a technique to improve communication that considers data access patterns of the entire program. Our approach is based on a combination of traditional data-flow analysis and a linear algebra framework, and works on structured programs with conditional statements and nested loops but without arbitrary goto statements. The distinctive features of the solution are the accuracy in keeping communication set information, support for general alignments and distributions including block-cyclic distributions and the ability to simulate some of the previous approaches with suitable modifications. We also show …

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Clouds: A Decision Tree Classifier For Large Datasets, Khaled Alsabti, Sanjay Ranka, Vineet Singh Jan 1998

Clouds: A Decision Tree Classifier For Large Datasets, Khaled Alsabti, Sanjay Ranka, Vineet Singh

Electrical Engineering and Computer Science - All Scholarship

Classification for very large datasets has many practical applications in data mining. Techniques such as discretization and dataset sampling can be used to scale up decision tree classifiers to large datasets. Unfortunately, both of these techniques can cause a significant loss in accuracy. We present a novel decision tree classifier called CLOUDS, which samples the splitting points for numeric attributes followed by an estimation step to narrow the search space of the best split. CLOUDS reduces computation and I/O complexity substantially compared to state of the art classifiers, while maintaining the quality of the generated trees in terms of accuracy …

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Design, Implementation, And Evaluation Of Parallell Pipelined Stap On Parallel Computers, Alok Choudhary, Wei-Keng Liao, Donald Weiner, Pramod Varshney, Richard Linderman, Mark Linderman Jan 1998

Design, Implementation, And Evaluation Of Parallell Pipelined Stap On Parallel Computers, Alok Choudhary, Wei-Keng Liao, Donald Weiner, Pramod Varshney, Richard Linderman, Mark Linderman

Electrical Engineering and Computer Science - All Scholarship

Performance results are presented for the design and implementation of parallel pipelined space-time adaptive processing (STAP) algorithms on parallel computers. In particular, the issues involved in parallelization, our approach to parallelization, and performance results on an Intel Paragon are described. The process of developing software for such an application on parallel computers when latency and throughput are both considered together is discussed and tradeoffs considered with respect to inter and intratask communication and data redistribution are presented. The results show that not only scalable performance was achieved for individual component tasks of STAP but linear speedups were obtained for the …

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Adaptive Linkage Crossover, Ayed A. Salman, Kishan Mehrotra, Chilukuri K. Mohan Jan 1998

Adaptive Linkage Crossover, Ayed A. Salman, Kishan Mehrotra, Chilukuri K. Mohan

Electrical Engineering and Computer Science - All Scholarship

Problem-specific knowledge is often implemented in search algorithms using heuristics to determine which search paths are to be explored at any given instant. As in other search methods, utilizing this knowledge will more quickly lead a genetic algorithm (GA) towards better results. In many problems, crucial knowledge is not found in individual components, but in the interrelations between those components. For such problems, we develop an interrelation (linkage) based crossover operator that has the advantage of liberating GAs from the constraints imposed by the fixed representations generally chosen for problems. The strength of linkages between components of a chromosomal structure …

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A Multithreaded Message-Passing System For High Performance Distributed Computing Applications, Sung-Yong Park, Joohan Lee, Salim Hariri Jan 1998

A Multithreaded Message-Passing System For High Performance Distributed Computing Applications, Sung-Yong Park, Joohan Lee, Salim Hariri

Electrical Engineering and Computer Science - All Scholarship

High Performance Distributed Computing (HPDC) applications require low-latency and high-throughput communication services and HPDC applications have different Quality of Service (QOS) requirements (e.g., bandwidth requirement, flow/error control algorithms, etc.). The communication services provided by traditional message-passing systems are fixed and thus can not be changed to meet the requirements of different HPDC applications. NYNET (ATM wide area network testbed in New York state) Communication System (NCS) is a multithreaded message-passing system developed at Syracuse University that provides high-performance and flexible communication services. In this paper, we overview the general architecture of NCS and present how NCS communication services are implemented. …

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Steady State Memetic Algorithm For Partial Shape Matching, Ender Ozcan, Chilukuri K. Mohan Jan 1998

Steady State Memetic Algorithm For Partial Shape Matching, Ender Ozcan, Chilukuri K. Mohan

Electrical Engineering and Computer Science - All Scholarship

Shape matching techniques are important in machine intelligence, especially in applications such as robotics. Currently, there are three major approaches to shape recognition: statistical, syntactic and neural approaches. This paper presents a fourth approach: evolutionary algorithms. A steady state memetic algorithm is shown to be successful in matching shapes even when they are partially obscured, and even in the presence of noise in the input image.

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Integrating Security Into The Curriculum, Cynthia E. Irvine, Shiu-Kai Chin, Deborah Frincke Jan 1998

Integrating Security Into The Curriculum, Cynthia E. Irvine, Shiu-Kai Chin, Deborah Frincke

Electrical Engineering and Computer Science - All Scholarship

The number of skilled practitioners of computer security who are able to address the complexities of modern technology and are familiar with successful approaches to system security is very small. People want security but are faced with two difficulties. First, they do not know how to achieve it in the context of their enterprises. They may not even know of a way to translate organizational procedures into policies, much less implement a set of mechanisms to enforce those policies. Second, they have no way of knowing whether their chosen mechanisms are effective. The recent US Presidential Commission on Critical Infrastructure …

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Partial Shape Matching Using Genetic Algorithms, Ender Ozcan, Chilukuri K. Mohan Jan 1998

Partial Shape Matching Using Genetic Algorithms, Ender Ozcan, Chilukuri K. Mohan

Electrical Engineering and Computer Science - All Scholarship

Shape recognition is a challenging task when images contain overlapping, noisy, occluded, partial shapes. This paper addresses the task of 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. We apply genetic algorithms to the partial shape-matching task. Preliminary results, using model shapes with 6 to 70 features each, are extremely encouraging.

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The Design And Evaluation Of A Virtual Distributed Computing Environment, Haluk Topcuoglu, Salim Hariri, Dongmin Kim, Yoonhee Kim, Xue Bing Jan 1998

The Design And Evaluation Of A Virtual Distributed Computing Environment, Haluk Topcuoglu, Salim Hariri, Dongmin Kim, Yoonhee Kim, Xue Bing

Electrical Engineering and Computer Science - All Scholarship

In this paper we present the Virtual Distributed Computing Environment (VDCE), a metacomputing environment currently being developed at Syracuse University. VDCE provides an efficient web-based approach for developing, evaluating and visualizing large-scale distributed applications that are based on predefined task libraries on diverse platforms. The VDCE task libraries relieve end-users of tedious task implementations and also support reusability. The VDCE software architecture is described in terms of three modules: a) the Application Editor, a user-friendly application development environment that generates the Application Flow Graph (AFG) of an application; b) the Application Scheduler, which provides an efficient task-to-resource mapping of AFG; …

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An Efficient Parallel Algorithm For High Dimensional Similarity Join, Khaled Alsabti, Sanjay Ranka, Vineet Singh Jan 1998

An Efficient Parallel Algorithm For High Dimensional Similarity Join, Khaled Alsabti, Sanjay Ranka, Vineet Singh

Electrical Engineering and Computer Science - All Scholarship

Multidimensional similarity join finds pairs of multi-dimensional points that are within some small distance of each other: The 6-k-d-B tree has been proposed as a data structure that scales better as the number of dimensions in-creases compared to previous data structures. We present a cost model of the E-k-d-B tree and use it to optimize the leaf size. We present novel parallel algorithms for the similarity join using the E-k-d-B tree. A load-balancing strategy based on equi-depth histograms is shown to work well for uniform or low-skew situations, whereas another based on weighted equi-depth histograms works far better for high-skew …

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Secure Delegation For Distributed Object Environments, Nataraj Nagaratnam, Doug Lea Jan 1998

Secure Delegation For Distributed Object Environments, Nataraj Nagaratnam, Doug Lea

Electrical Engineering and Computer Science - All Scholarship

SDM is a Secure Delegation Model for Java-based distributed object environments. SDM extends current Java security features to support secure remote method invocations that may involve chains of delegated calls across distributed objects. The framework supports a control API for application developers to specify mechanisms and security policies surrounding simple or cascaded delegation. Delegation may also be disabled and optionally revoked. These policies may be controlled explicitly in application code, or implicitly via administrative tools.

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A Problem Solving Environment For Network Computing, Salim Hariri, Haluk Topcuoglu, Wojtek Furmanski, Dongmin Kim, Yoonhee Kim Jan 1998

A Problem Solving Environment For Network Computing, Salim Hariri, Haluk Topcuoglu, Wojtek Furmanski, Dongmin Kim, Yoonhee Kim

Electrical Engineering and Computer Science - All Scholarship

The current advances in high-speed networks and WWW technologies have made network computing a cost-effective high performance computing environment. New software development models and problem solving environments must be developed to utilize the network computing environment efficiently. In this paper we present Virtual Distributed Computing Environment (VDCE), which provides a problem solving environment for high-performance distributed computing over wide-area networks. VDCE enables scientists to develop distributed applications without knowing the detailed architecture of the underlying resources. VDCE provides well-defined library functions that relieve end users from tedious task implementations and it supports software reusability. The VDCE software architecture consists of …

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Automatic Granularity Control For Load Balancing Of Concurrent Particle Simulations, Marc Rieffel, Stephen Taylor, Jerrell Watts Jan 1998

Automatic Granularity Control For Load Balancing Of Concurrent Particle Simulations, Marc Rieffel, Stephen Taylor, Jerrell Watts

Electrical Engineering and Computer Science - All Scholarship

This paper demonstrates the use of automatic granularity control as part of dynamic load balancing for irregular, particle-based simulations. Performance optimization techniques are considered in the context of a concurrent Direct Simulation Monte Carlo method used to study the rarefied gas flow inside three-dimensional plasma reactors. Several computational techniques are used to reduce the overall time to deliver realistic threedimensional results. The effectiveness of dynamic load balancing and granularity control are presented for large-scale simulations on distributed-memory multicomputers.

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Automatic Granularity Control For Load Balancing Of Concurrent Particle Simulations, Marc Rieffel, Stephen Taylor, Jerrell Watts Jan 1998

Automatic Granularity Control For Load Balancing Of Concurrent Particle Simulations, Marc Rieffel, Stephen Taylor, Jerrell Watts

Electrical Engineering and Computer Science - All Scholarship

This paper demonstrates the use of automatic granularity control as part of dynamic load balancing for irregular, particle-based simulations. Performance optimization techniques are considered in the context of a concurrent Direct Simulation Monte Carlo method used to study the rarefied gas flow inside three-dimensional plasma reactors. Several computational techniques are used to reduce the overall time to deliver realistic threedimensional results. The effectiveness of dynamic load balancing and granularity control are presented for large-scale simulations on distributed-memory multicomputers.

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Performance Enhancement Using Intra-Server Caching In A Continuous Media Server, Chutimet Srinilta, Alok Choudhary Jan 1998

Performance Enhancement Using Intra-Server Caching In A Continuous Media Server, Chutimet Srinilta, Alok Choudhary

Electrical Engineering and Computer Science - All Scholarship

Continuity of stream playback is the crucial constraint in designing a continuous media server. From a distributed memory architectural model developed earlier, we found that there were many points where the stream capacity of the server could be improved. The stream capacity was usually limited by the storage bottlenecks. Serving streams from memory cache eliminates disk accesses and data transfers between nodes which, in turn, helps relieve those bottlenecks. However, the capacity of the server ultimately depends on client access pattern. Client request assignment has an impact on cache hit ratio as well as workload distribution. It is also the …

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