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Syracuse University

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Articles 151 - 180 of 532

Full-Text Articles in Computer Sciences

Interacting Data Services For Distributed Earthquake Modeling, Marlon Pierce, Choonhan Youn, Geoffrey C. Fox Jan 2003

Interacting Data Services For Distributed Earthquake Modeling, Marlon Pierce, Choonhan Youn, Geoffrey C. Fox

Electrical Engineering and Computer Science - All Scholarship

We present XML schemas and our design for related data services for describing faults and surface displacements, which we use within earthquake modeling codes. These data services are implemented using a Web services approach and are incorporated in a portal architecture with other, general purpose services for application and file management. We make use of many Web services standards, including WSDL and SOAP, with specific implementations in Java. We illustrate how these data models and services may be used to build distributed, interacting applications through data flow.

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An Adaptive Qos Routing Protocol With Dispersity For Ad-Hoc Networks, Youngki Hwang, Pramod Varshney Jan 2003

An Adaptive Qos Routing Protocol With Dispersity For Ad-Hoc Networks, Youngki Hwang, Pramod Varshney

Electrical Engineering and Computer Science - All Scholarship

In this paper, we present the design and simulation of a bandwidth constrained multiple path on-demand routing protocol for ad-hoc networks to support end-to-end Quality of Service, which is known as the Adaptive Dispersity QoS Routing (ADQR) Protocol. We propose a route discovery algorithm to find multiple disjoint paths with longerlived connections, where each path also specifies associated network resource information. This provides an efficient approach for network resource reservation combined with data dispersion and for route maintenance. A longerlived path generally involves less route maintenance, resulting in an increase of bandwidth utilization. We propose a route maintenance algorithm to …

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Building Problem Solving Environments With Application Web Service Toolkits, Choonhan Youn, Marlon Pierce, Geoffrey C. Fox Jan 2003

Building Problem Solving Environments With Application Web Service Toolkits, Choonhan Youn, Marlon Pierce, Geoffrey C. Fox

Electrical Engineering and Computer Science - All Scholarship

Application portals, or Problem Solving Environments (PSEs), provide user environments that simplify access and integrate various distributed computational services for scientists working on particular classes of problems. Specific application portals are typically built on common sets of core services, so reusability of these services is a key problem in PSE development. In this paper we address the reusability problem by presenting a set of core services built using the Web services model and application metadata services that can be used to build science application front ends out of these core services.

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Sensor Communication Networks Using Swarming Intelligence, Rajani Muraleedharan, Lisa Ann Osadciw Jan 2003

Sensor Communication Networks Using Swarming Intelligence, Rajani Muraleedharan, Lisa Ann Osadciw

Electrical Engineering and Computer Science - All Scholarship

Energy consumption is currently a key issue in research for future sensor networks. This paper presents a novel approach to sensor network routing based on energy consumption. The unique routing algorithm uses swarm intelligence, which is computationally efficient.

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An Integrated Videoconferencing System For Heterogeneous Multimedia Collaboration, Ahmet Uyar, Wenjun Wu, Hasan Bulut, Geoffrey C. Fox Jan 2003

An Integrated Videoconferencing System For Heterogeneous Multimedia Collaboration, Ahmet Uyar, Wenjun Wu, Hasan Bulut, Geoffrey C. Fox

Electrical Engineering and Computer Science - All Scholarship

We have developed an integrated conferencing system, Global Multimedia Collaboration System, which enables heterogeneous multimedia clients to join the same real-time sessions. Our system provides support for a variety of protocols and applications, including H.323 clients, SIP clients and Access Grid rooms. In this paper, we would like to show the features and design principles of our conferencing server which facilitates audio and video communications among participating clients in a real-time conference.

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Distributed And Multiprocessor Scheduling, Steven J. Chapin, Jon B, Weissman Jan 2002

Distributed And Multiprocessor Scheduling, Steven J. Chapin, Jon B, Weissman

Electrical Engineering and Computer Science - All Scholarship

This chapter discusses CPU scheduling in parallel and distributed systems. CPU scheduling is part of a broader class of resource allocation problems, and is probably the most carefully studied such problem. The main motivation for multiprocessor scheduling is the desire for increased speed in the execution of a workload. Parts of the workload, called tasks, can be spread across several processors and thus be executed more quickly than on a single processor. In this chapter, we will examine techniques for providing this facility. The scheduling problem for multiprocessor systems can be generally stated as \How can we execute a set …

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Buffer Overflow And Format String Overflow Vulnerabilities, Kyung-Suk Lhee, Steve J. Chapin Jan 2002

Buffer Overflow And Format String Overflow Vulnerabilities, Kyung-Suk Lhee, Steve J. Chapin

Electrical Engineering and Computer Science - All Scholarship

This article surveys representative techniques of exploiting buffer overflow and format string overflow vulnerabilities and their currently available defensive measures. We also describe our buffer overflow detection technique that range checks the referenced buffers at run time. We augment executable files with type information of automatic buffers (local variables and parameters of functions) and static buffers (global variables in the data/bss section), and maintain the sizes of allocated heap buffers in order to detect an actual occurrence of buffer overflow. We describe a simple implementation with which we currently protect vulnerable copy functions in the C library.

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Perspectives On The Evolution Of Simulation, Richard E. Nance, Robert G. Sargent Jan 2002

Perspectives On The Evolution Of Simulation, Richard E. Nance, Robert G. Sargent

Electrical Engineering and Computer Science - All Scholarship

Simulation is introduced in terms of its different forms and uses, but the focus on discrete event modeling for systems analysis is dominant as it has been during the evolution of the technique within operations research and the management sciences. This evolutionary trace of over almost fifty years notes the importance of bidirectional influences with computer science, probability and statistics, and mathematics. No area within the scope of operations research and the management sciences has been affected more by advances in computing technology than simulation. This assertion is affirmed in the review of progress in those technical areas that collectively …

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From Computational Science To Internetics: Integration Of Science With Computer Science, Geoffrey C. Fox Jan 2002

From Computational Science To Internetics: Integration Of Science With Computer Science, Geoffrey C. Fox

Northeast Parallel Architecture Center

We describe how our world dominated by Science and Scientists has been changed revolutionized by technologies moving with Internet time. Computers have always been well-used tools but in the beginning only the science counted and little credit or significance was attached to any computing activities associated with scientific research. Some 20 years ago, this started to change and the area of computational science gathered support with the NSF Supercomputer centers playing a critical role. However this vision has stalled over the last 5 years with information technology increasing in importance. The Holy Grail of computational science-- scalable parallel computing-- is …

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Integration Of Naradabrokering And Audio/Video Conferencing As A Web Service, Hasan Bulut, Geoffrey C. Fox, Shrideep Pallickara, Ahmet Uyar, Wenjun Wu Jan 2002

Integration Of Naradabrokering And Audio/Video Conferencing As A Web Service, Hasan Bulut, Geoffrey C. Fox, Shrideep Pallickara, Ahmet Uyar, Wenjun Wu

Electrical Engineering and Computer Science - All Scholarship

Audio/Video Conferencing Systems need communication channels between their clients in order to transport RTP packets from one client to another. In this paper we investigate audio/video conferencing as a Web Service and the deployment of publish/subscribe systems in the context of audio/video conferencing systems. In this paper we use our research system NaradaBrokering, which supports both peer-to-peer and publish/subscribe paradigms, as a test bed to investigate these ideas. We also present results from our research system.

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Building Decision Tree Classifier On Private Data, Wenliang Du, Zhijun Zhan Jan 2002

Building Decision Tree Classifier On Private Data, Wenliang Du, Zhijun Zhan

Electrical Engineering and Computer Science - All Scholarship

This paper studies how to build a decision tree classifier under the following scenario: a database is vertically partitioned into two pieces, with one piece owned by Alice and the other piece owned by Bob. Alice and Bob want to build a decision tree classifier based on such a database, but due to the privacy constraints, neither of them wants to disclose their private pieces to the other party or to any third party. We present a protocol that allows Alice and Bob to conduct such a classifier building without having to compromise their privacy. Our protocol uses an untrusted …

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A Survey Of Various Frequency Domain Integral Equations For The Analysis Of Scattering From Three-Dimensional Dielectric Objects, Baek Ho Jung, T. K. Sarkar, Y.-S. Chung Jan 2002

A Survey Of Various Frequency Domain Integral Equations For The Analysis Of Scattering From Three-Dimensional Dielectric Objects, Baek Ho Jung, T. K. Sarkar, Y.-S. Chung

Electrical Engineering and Computer Science - All Scholarship

In this paper, we present four different formulations for the analysis of electromagnetic scattering from arbitrarily shaped three-dimensional (3-D) homogeneous dielectric body in the frequency domain. The four integral equations treated here are the electric field integral equation (EFIE), the magnetic field integral equation (MFIE), the combined field integral equation (CFIE), and the PMCHW (Poggio, Miller, Chang, Harrington, and Wu) formulation. For the CFIE case, we propose eight separate formulations with different combinations of expansion and testing functions that result in sixteen different formulations of CFIE. One of the objectives of this paper is to illustrate that not all CFIE …

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Interoperable Web Services For Computational Portals, Marlon Pierce, Geoffrey C. Fox, Choonhan Youn, Steve Mock, Kurt Mueller Jan 2002

Interoperable Web Services For Computational Portals, Marlon Pierce, Geoffrey C. Fox, Choonhan Youn, Steve Mock, Kurt Mueller

Electrical Engineering and Computer Science - All Scholarship

Computational web portals are designed to simplify access to diverse sets of high performance computing resources, typically through an interface to computational Grid tools. An important shortcoming of these portals is their lack of interoperable and reusable services. This paper presents an overview of research efforts undertaken by our group to build interoperating portal services around a Web Services model. We present a comprehensive view of an interoperable portal architecture, beginning with core portal services that can be used to build Application Web Services, which in turn may be aggregated and managed through portlet containers.

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A Practical Approach To Solve Secure Multi-Party Computation Problems, Wenliang Du, Zhijun Zhan Jan 2002

A Practical Approach To Solve Secure Multi-Party Computation Problems, Wenliang Du, Zhijun Zhan

Electrical Engineering and Computer Science - All Scholarship

Secure Multi-party Computation (SMC) problems deal with the following situation: Two (or many) parties want to jointly perform a computation. Each party needs to contribute its private input to this computation, but no party should disclose its private inputs to the other parties, or to any third party. With the proliferation of the Internet, SMC problems becomes more and more important. So far no practical solution has emerged, largely because SMC studies have been focusing on zero information disclosure, an ideal security model that is expensive to achieve. Aiming at developing practical solutions to SMC problems, we propose a new …

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Inter-Domain Lsp Setup Using Bandwidth Management Points, Ibrahim Taner Okumus, Junseok Hwang, Haci Ali Mantar, Steve J. Chapin Jan 2001

Inter-Domain Lsp Setup Using Bandwidth Management Points, Ibrahim Taner Okumus, Junseok Hwang, Haci Ali Mantar, Steve J. Chapin

Electrical Engineering and Computer Science - All Scholarship

Bandwidth Management Points (BMP) are a necessity to manage the intra and inter-domain resources in the Internet. In this paper we propose a way to setup inter-domain Label Switched Path (LSP) with the help of a BMP in a MultiProtocol Label Switching (MPLS) over DiffServ network. We use extended Simple Inter-domain Bandwidth Broker Signalling Protocol (SIBBS) to distribute the labels inter-domain. We also use a BMP to interact with the MPLS to setup the intra-domain LSP and to provision the intra-domain traffic. With the help of a BMP, we show how end-to-end Quality of Service (QoS) can be achieved.

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Examining The Reflective Outcomes Of Asynchronous Computer-Mediated Communication On Inservice Teacher Development, Mark Hawkes, Alexander Romiszowski Jan 2001

Examining The Reflective Outcomes Of Asynchronous Computer-Mediated Communication On Inservice Teacher Development, Mark Hawkes, Alexander Romiszowski

Instructional Design, Development and Evaluation - All Scholarship

This study explored the professional development experiences of 28 practicing teachers in 10 Chicago suburban schools involved in a two-year technology supported Problem-Based Learning curriculum development effort. Asynchronous computer-mediated communications (CMC) were featured as teacher communication tools of the project. The computer-mediated discourse produced by the teachers was compared with the discourse produced by teachers in face-to-face meetings. Research methods including discourse analysis and archival data analysis were applied to determine the nature of the teacher discourse and its reflective content. The results show that while the computer-mediated teacher dialogue was less interactive, it was significantly more reflective (t=4.14, p=.001) …

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Privacy-Preserving Cooperative Statistical Analysis, Wenliang Du, Mikhail J. Atallah Jan 2001

Privacy-Preserving Cooperative Statistical Analysis, Wenliang Du, Mikhail J. Atallah

Electrical Engineering and Computer Science - All Scholarship

The growth of the Internet opens up tremendous opportunities for cooperative computation, where the answer depends on the private inputs of separate entities. Sometimes these computations may occur between mutually untrusted entities. The problem is trivial if the context allows the conduct of these computations by a trusted entity that would know the inputs from all the participants; however if the context disallows this then the techniques of secure multi-party computation become very relevant and can provide useful solutions. Statistic analysis is a widely used computation in real life, but the known methods usually require one to know the whole …

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Parallel Suffix Sorting, Natsuhiko Futamura, Srinivas Aluru, Stefan Kurtz Jan 2001

Parallel Suffix Sorting, Natsuhiko Futamura, Srinivas Aluru, Stefan Kurtz

Electrical Engineering and Computer Science - All Scholarship

We present a parallel algorithm for lexicographically sorting the suffixes of a string. Suffix sorting has applications in string processing, data compression and computational biology. The ordered list of suffixes of a string stored in an array is known as Suffix Array, an important data structure in string processing and computational biology. Our focus is on deriving a practical implementation that works well for typical inputs rather than achieving the best possible asymptotic running-time for artificial, worst-case inputs. We experimentally evaluated our algorithm on an IBM SP-2 using genomes of several organisms. Our experiments show that the algorithm delivers good, …

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Interdomain Resource Reservation Via Third-Party Agent, Haci Ali Mantar, Junseok Hwang, Ibrahim Taner Okumus, Steve J. Chapin Jan 2001

Interdomain Resource Reservation Via Third-Party Agent, Haci Ali Mantar, Junseok Hwang, Ibrahim Taner Okumus, Steve J. Chapin

Electrical Engineering and Computer Science - All Scholarship

This paper describes interdomain resource reservation through a third-party agent called a Bandwidth Management Point (BMP). The BMP of each domain is responsible for admission control, dynamic bandwidth provisioning, DSCP assignment, policy control, etc. We also propose that each domain be free to choose its own intradomain resource reservation protocol.This model solves two significant problems of today's Internet: interdomain dynamic resource provisioning, and scalability of the backbone. The BMP makes bulk reservations with each possible destination domain on behalf of hosts in its domain, and end hosts can join or leave the reservation without being involved with communication protocol between …

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Jobqueue: A Computational Grid-Wide Queuing System, Dimitros Katramatos, Marty Humphrey, Andrew Grimshaw, Steve Chapin Jan 2001

Jobqueue: A Computational Grid-Wide Queuing System, Dimitros Katramatos, Marty Humphrey, Andrew Grimshaw, Steve Chapin

Electrical Engineering and Computer Science - All Scholarship

In a Computational Grid, it is not easy to maintain grid-wide control over the number of executing jobs, as well as a global view of the status of submitting jobs, due to the heterogeneity in resource type, availability, and access policies. This paper describes the design and implementation of JobQueue, which is a Computational Grid-wide queuing system, or metaqueuing system, implemented in Legion. JobQueue is unique because of its ability to span multiple administrative domains. It can also be reconfigured dynamically along a number of dimensions and in the general case does not require special privileges to create, facilitating new …

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Secure Multi-Party Computation Problems And Their Applications: A Review And Open Problems, Wenliang Du, Mikhail J. Atallah Jan 2001

Secure Multi-Party Computation Problems And Their Applications: A Review And Open Problems, Wenliang Du, Mikhail J. Atallah

Electrical Engineering and Computer Science - All Scholarship

The growth of the Internet has triggered tremendous opportunities for cooperative computation, where people are jointly conducting computation tasks based on the private inputs they each supplies. These computations could occur between mutually untrusted parties, or even between competitors. For example, customers might send to a remote database queries that contain private information; two competing financial organizations might jointly invest in a project that must satisfy both organizations' private and valuable constraints, and so on. Today, to conduct such computations, one entity must usually know the inputs from all the participants; however if nobody can be trusted enough to know …

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Time-Domain Electric-Field Integral Equation With Central Finite Difference, Baek Ho Jung, Tapan Kumar Sarkar Jan 2001

Time-Domain Electric-Field Integral Equation With Central Finite Difference, Baek Ho Jung, Tapan Kumar Sarkar

Electrical Engineering and Computer Science - All Scholarship

In this paper, we present a new formulation using the time-domain electric-field integral equation (TD-EFIE) to obtain a transient scattering response from arbitrarily shaped conducting bodies. The time derivative of the magnetic vector potential is approximated with a central finite difference, and the scalar potential is time averaged by dividing it into two terms. This approach with an implicit method using central-difference results in accurate and stable transient scattering responses from conducting objects. Detailed mathematical steps are included, and several numerical results are presented.

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Mpj: Mpi-Like Message Passing For Java, Bryan Carpenter, Vladimir Getov, Glenn Judd, Anthony Skjellum, Geoffrey C. Fox Jan 2000

Mpj: Mpi-Like Message Passing For Java, Bryan Carpenter, Vladimir Getov, Glenn Judd, Anthony Skjellum, Geoffrey C. Fox

Northeast Parallel Architecture Center

Recently, there has been a lot of interest in using Java for parallel programming. Efforts have been hindered by lack of standard Java parallel programming APIs. To alleviate this problem, various groups started projects to develop Java message passing systems modeled on the successful Message Passing Interface (MPI). Official MPI bindings are currently defined only for C, Fortran, and C++, so early MPI-like environments for Java have been divergent. This paper related an effort undertaken by a working group of the Java Grande Forum, seeking a consensus on an MPI-like API, to enhance the viability of parallel programming using Java.

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Parallel Computers And Complex Systems, Geoffrey C. Fox, Paul D. Coddington Jan 2000

Parallel Computers And Complex Systems, Geoffrey C. Fox, Paul D. Coddington

Northeast Parallel Architecture Center

We present an overview of the state of the art and future trends in high performance parallel and distributed computing, and discuss techniques for using such computers in the simulation of complex problems in computational science. The use of high performance parallel computers can help improve our understanding of complex systems, and the converse is also true — we can apply techniques used for the study of complex systems to improve our understanding of parallel computing. We consider parallel computing as the mapping of one complex system — typically a model of the world — into another complex system — …

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An Hpspmd Programming Model, Bryan Carpenter, Geoffrey C. Fox, Guansong Zhang Jan 2000

An Hpspmd Programming Model, Bryan Carpenter, Geoffrey C. Fox, Guansong Zhang

Northeast Parallel Architecture Center

Building on research carried out in the Parallel Compiler Runtime Consortium (PCRC) project, this article discusses a language model that combines characteristic data-parallel features from the HPF standard with an explicitly SPMD programming style. This model, which we call the HPspmd model, is designed to facilitate direct calls to established libraries for parallel programming with distributed data. We describe a Java-based HPspmd language called HPJava.

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A Pairwise Key Pre-Distribution Scheme For Wireless Sensor Networks, Wenliang Kevin Du, Jing Deng, Yunghsiang S. Han, Pramod K. Varshney Jan 2000

A Pairwise Key Pre-Distribution Scheme For Wireless Sensor Networks, Wenliang Kevin Du, Jing Deng, Yunghsiang S. Han, Pramod K. Varshney

Electrical Engineering and Computer Science - All Scholarship

This paper, we provide a framework in which to study the security of key pre-distribution schemes, propose a new key pre-distribution scheme which substantially improves the resilience of the network compared to previous schemes, and give an in-depth analysis of our scheme in terms of network resilience and associated overhead. Our scheme exhibits a nice threshold property: when the number of compromised nodes is less than the threshold, the probability that communications between any additional nodes are compromised is close to zero. This desirable property lowers the initial payoff of smaller-scale network breaches to an adversary, and makes it necessary …

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Multi-Phase Discrete Particle Swarm Optimization, Buthainah Sabeeh No'man Al-Kazemi, Chilukuri K. Mohan Jan 2000

Multi-Phase Discrete Particle Swarm Optimization, Buthainah Sabeeh No'man Al-Kazemi, Chilukuri K. Mohan

Electrical Engineering and Computer Science - All Scholarship

This paper describes a successful adaptation of the Particle Swarm Optimization algorithm to discrete optimization problems. In the proposed algorithm, particles cycle through multiple phases with differing goals. We also exploit hill climbing. On benchmark problems, this algorithm outperforms a genetic algorithm and a previous discrete PSO formulation.

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Java’S Insecure Parallelism, Per Brinch Hansen Jan 1999

Java’S Insecure Parallelism, Per Brinch Hansen

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

The author examines the synchronization features of Java and finds that they are insecure variants of his earliest ideas in parallel programming published in 1972-73. The claim that Java supports monitors is shown to be false. The author concludes that Java ignores the last twenty-five years of research in parallel programming languages.

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Formal Development Of Secure Email, Dan Zhou, Joncheng C. Kuo, Susan Older, Shiu-Kai Chin Jan 1999

Formal Development Of Secure Email, Dan Zhou, Joncheng C. Kuo, Susan Older, Shiu-Kai Chin

Electrical Engineering and Computer Science - All Scholarship

Developing systems that are assured to be secure requires precise and accurate descriptions of specifications, designs, implementations, and security properties. Formal specification and verification have long been recognized as giving the highest degree of assurance. In this paper, we describe a software development process that integrates formal verification and synthesis. We demonstrate this process by developing assured sender and receiver C++ code for a secure electronic mail system, Privacy Enhanced Mail. We use higher-order logic for system-requirements specification, design specifications and design verification. We use a combination of higher-order logic and category theory and tools supporting these formalisms to refine …

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The Gateway System: Uniform Web Based Access To Remote Resources, Geoffrey C. Fox, Tomasz Haupt, Erol Akarsu, Alexey Kalinichenko, Kang-Seok Kim Jan 1999

The Gateway System: Uniform Web Based Access To Remote Resources, Geoffrey C. Fox, Tomasz Haupt, Erol Akarsu, Alexey Kalinichenko, Kang-Seok Kim

Northeast Parallel Architecture Center

Exploiting our experience developing the WebFlow system, we designed the Gateway system to provide seamless and secure access to computational resources at ASC MSRC. The Gateway follows our commodity components strategy, and it is implemented as a modern three-tier system. Tier 1 is a high-level front end for visual programming, steering, run-time data analysis and visualization that is built on top of the Web and OO commodity standards. Distributed object-based, scalable, and reusable Web server and Object broker middleware forms Tier 2. Back-end services comprise Tier 3. In particular, access to high-performance computational resources is provided by implementing the emerging …

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