Digital Commons Network^™

Parallel Detection Of Closed Streamlines In Planar Flows, Thomas Wischgoll, Gerik Scheuermann, Hans Hagen

Computer Science and Engineering Faculty Publications

No abstract provided.

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, …

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 …

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 …

Multicast Communication In Circuit-Switched Optical Networks, Ran Libeskind-Hadas, Rami Melhem

All HMC Faculty Publications and Research

In this paper we examine the problem of multicast routing in Wavelength-division multiplexed (WDM) optical networks. In particular, we examine wavelength and routing assignment problems in circuit-switched WDM networks. We show that although the routing and wavelength assignment (RWA) problem is NP-complete in general, the wavelength assignment (WA) problem can be solevd in a polynomial time.

Design Verification And Functional Testing Of Finite State Machines, Mark W. Weiss, Sharad C. Seth, Shashank K. Mehta, Kent L. Einspahr

School of Computing: Conference and Workshop Papers

The design of a finite state machine can be verified by simulating all its state transitions. Typically, state transitions involve many don’t care inputs that must be fully expanded for an exhaustive functional verification. However, by exploiting the knowledge about the design structure it is shown that only a few vectors from the fully expanded set suffice for both design verification and testing for manufacturing defects. The main contributions of the paper include a unified fault model for design errors and manufacturing faults and a function-based analysis of the circuit structure for the purpose of generating tests under the unified …

Diffserver: Application Level Differentiated Services For Web Servers, Gautam Rao, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Web content hosting, in which a Web server stores and provides Web access to documents for different customers, is becoming increasingly common. For example, a web server can host webpages for several different companies and individuals. Traditionally, Web Service Providers (WSPs) provide all customers with the same level of performance (best-effort service). Most service differentiation has been in the pricing structure (individual vs. business rates) or the connectivity type (dial-up access vs. leased line, etc.). This report presents DiffServer, a program that implements two simple, server-side, application-level mechanisms (server-centric and client-centric) to provide different levels of web service. The results …

Latent Maximum Entropy Principle For Statistical Language Modeling, Shaojun Wang, Ronald Rosenfeld, Yunxin Zhao

Kno.e.sis Publications

We describe a unified probabilistic framework for statistical language modeling, the latent maximum entropy principle. The salient feature of this approach is that the hidden causal hierarchical dependency structure can be encoded into the statistical model in a principled way by mixtures of exponential families with a rich expressive power. We first show the problem formulation, solution, and certain convergence properties. We then describe how to use this machine learning technique to model various aspects of natural language, such as syntactic structure of sentences, semantic information in a document. Finally, we draw a conclusion and point out future research directions.

Aggregated Hierarchical Multicast For Active Networks, Tilman Wolf, Sumi Y. Choi

All Computer Science and Engineering Research

Active Networking is the basis for a range of new and innovative applications that make use of computational resources inside network routers. One such application is Aggregated Hierarchical Multicast, which aims at implementing efficient many-to-many communication. In certain scenarios it is possible to transmit less accurate, aggregated data and thus achieve better scalability. Using Active Networks, this aggregation computation can be done transparently by network routers without end system support. We present how aggregated data streams can be structured in a hierarchical fashion to allow easy access of data at the desired aggregation level. We introduce two application examples to …

A Proposal For A Scalable Internet Multicast Architecture, Sherlia Shi

All Computer Science and Engineering Research

We propose a new network and system architecture for multicast in the Internet. Our main objectives are to find a cost-effective way to scale to a large number of multicast groups whose members are geographically dispersed, and to enable small and less capable devices to participate in group communications. In order to preserve the efficiency of data distribution gained by multicast, while avoiding the control complexity previously exhibited by IP multicast, we propose the use of an overlay network for multicast services. We construct "virtual" multicast trees, which consist of unicast connections joining multicast servers in the network. These servers …

Network Abstractions For Context-Aware Mobile Computing, Gruia-Catalin Roman, Christine Julien, Qingfeng Huang

All Computer Science and Engineering Research

Context-Aware computing is characterized by the ability of a software system to continuously adapt its behavior to a changing environment over which it has little or no control. Previous work along these lines presumed a rather narrow definition of context, one that was centered on resources immediately available to the component in question, e.g., communication bandwidth, physical location, etc. This paper explores context-aware computing in the setting of ad hoc networks consisting of numerous mobile hosts that interact with each other opportunistically via transient wireless interconnections. We extend the context to encompass awareness of an entire neighborhood within the ad …

Relying On Safe Distance To Ensure Consistent Group Membership In Ad Hoc Networks, Qingfeng Huang, Christine Julien, Gruia-Catalin Roman, Ali Hazemi

All Computer Science and Engineering Research

The design of ad hoc mobile applications often requires the availability of a consistent view of the application state among the participating hosts. Such views are important because they simplify both the programming and verification tasks. Essential to constructing a consitent view is the ability to know what hosts are within proximity of each other, i.e., form a group in support of the particular application. In this paper we propose a protocol that allows hosts within communication range to maintain a consistent view of the group membership despite movement and frequent disconnections. The novel features of this protocol are its …

Indra: A Distributed Approach To Network Intrusion Detection And Prevention, Qi Zhang, Ramaprabhu Janakiraman

All Computer Science and Engineering Research

While advances in computer and communications technology have made the network ubiquitous, they ahve also rendered networked systems vulnerable to malicious attacks orchestrated from a distance. These attacks, usually called cracker attacks or intrusions, start with crackers infiltrating a network through a vulnerable host and then going on to launch further attacks. Crackers depend on increasingly sophisticated techniques like using distributed attack sources. On the other hand, software that guards against them remains rooted in traditional centralized techniques, presenting an easily-targetable single point of failure. Scalable, distributed network intrusion prevention software is sorely needed. We propose Indra - a distributed …

Towards Comparative Profiling Of Parallel Applications With Pperfdb, Christian Leland Hansen

Dissertations and Theses

Due to the complex nature of parallel programming, it is difficult to diagnose and solve performance related problems. Knowledge of program behavior is obtained experimentally, with repeated runs of a slightly modified version of the application or the same code in different environments. In these circumstances, comparative performance analysis can provide meaningful insights into the subtle effects of system and code changes on parallel program behavior by highlighting the difference in performance results across executions.

I have designed and implemented modules which extend the PPerfDB performance tool to allow access to existing performance data generated by several commonly used tracing …

Tackling The Deficit - It Solutions For Art Appreciation - Needs Study And Provision Project At Primary School Level., Séan Ó Hargáin

Theses

This project looks at the changing environment in terms of the approach to the Visual Arts curriculum at Primary School level. It aims to provide an innovative solution to the art appreciation area, which is being given equal status with the art creation area, which traditionally has been the main focus of the curriculum.

The Project includes a review of the curricular climate, both at home and abroad. In this context it focusses particularly on the role of Information Technology in addressing access problems from those living remote from major population, and therefore major artistic centres.

Primary Research included involved …

An Approach To Networking In Irish Primary Schools, Donal A. O'Connor

Theses

In this Thesis, I hope to develop an approach to networking in the Irish Primary school which will provide practical as well as theoretical advice to Primary Teachers. In the pages that follow, I will detail a general outline of the principles of computer networking and detail models appropriate to the primary school.

At the outset, I wish to acknowledge that there are as many solutions to the primary school’s networking requirements as there are individual schools. This document is intended as a general set of guidelines for the average Primary school in this country. By this, I mean schools …

A Fresh Look At The Provision Of Bandwidth To A Health Agency, James G. Leahy

Theses

This thesis describes development of a networking infrastructure to support a Regional Health Service in Ireland. It covers:-

• The design, building, commissioning and delivery of a Forward Emergency Control Vehicle to provide the video, voice and data communications needed to enhance delivery of patient care in Disaster Situations. The main focus here is on the integration of satellite and terrestrial communications.

• By studying the history of telecommunications provision over copper, the best use is made of the legacy copper cabling in and between existing buildings on a campus to provide both voice and data services.

• A financial …

A Case For Systems Thinking And System Dynamics, Craig William Caulfield, Stanislaw P. Maj

Research outputs pre 2011

Systems thinking is a way of thinking that focuses on the relationships between the parts forming a purposeful whole. System dynamics is concerned with building computer models of complex problem situations and then experimenting with and studying the behaviour of these models over time. This paper is a review of systems thinking that considers its unique history and influences, paradigms and methodologies, and presents a case for the system dynamics methodology as the best tool for the most diverse range of problem situations

Hopfield Model For Shortest Path Computation And Routing In Atm Network, Chee Weng Lee

Student Works (2000-2009)

This research focuses on the application of Hopfield neural network and Boltmann machine in solving the shortest path routing problem in the ATM network environment. Hopfield neural network and Boltzmann machine are two types of neural network which are commonly used for solving optimization problem such as the shortest path routing problem. The objectives of this research are to construct a Hopfield neural network and a Boltzmann machine for solving the shortest path routing problem in the ATM network. Both of these two types of neural network are built based on a chosen example of an A TM network. The …

Digital Library Of Thesis, Fong Fong Chong

Student Works (2000-2009)

Digital library of thesis is a web-based library system for submitting, storing and disseminating or theses electronically. This system is proposed to overcome the short comings of the traditional methods of storing and disseminating or printed thesis. Users can use this system to upload their theses in the electronic form to the server and the theses can be retrieved using the efficient search capabilities provided. Source codes can be stored in this system too. This system provides an efficient way or handling source codes by storing the source codes in the reusable components or object form. This is to promote …

Network Simulation And Performance Evalution Of Ip Multicast Using Pim-Dm In Umjanetsim, Jui Hiangh Teoh

Student Works (2000-2009)

The demand for multicast capabilities in IP networks is growing very rapidly. New applications that take advantage of IP Multicast are being introduced constantly. Therefore, IP Multicast is regarded as one of the most important technologies in IP networks today. This dissertation focuses on the simulation and performance evaluation of IP Multicast using Protocol Independent Multicast- Dense Mode (PIM-OM) as the multicast routing protocol. The simulation is executed in a network simulator named UMJaNetSim, where custom components are built in order to simulate IP Multicast. First, the advantages and applications of IP Multicast, multicast addressing, Internet Group Management Protocol (IGMP), …

Mpls Vpn Simulation Using Mp-Ibgp, Tan Fong Ang

Student Works (2000-2009)

As Internet traffic continues to increase, companies are demanding greater speeds and better services to disseminate information to their customers, partners and employees. In order to provide reliable services and to support a variety of secure communications among a wide range of locations, Multiprotocol Label Switching Virtual Private Network (MPLS VPN) has been introduced. MPLS is an emerging technology that aims to address many of the existing issues associated with packet forwarding in today's internetworking environment. Whereas, VPN provides secure private connections through public infrastructure amongst multiple locations. MPLS­ based VPN provides isolation. security, simplified routing, easier provisioning as well …

Dynamic Bandwidth Allocation Using Neural-Fuzzy In Atm Network, Yan Sing Chua

Student Works (2000-2009)

Dynamic bandwidth allocation is becoming one of the crucial issues in the design and research in the computer network. This is due to the continuous increasing demand of intensive applications that require more bandwidth while retaining higher quality. Dynamic bandwidth allocation utilises the current network state information to optimise the bandwidth distribution. The state information can be gathered through prediction using past data and measurement on current state. Agility and flexibility of dynamic bandwidth allocation using Neural-Fuzzy has the advantage that it can adapt to the state changes of the network. ATM network carries heterogeneous traffic and this causes the …

Laman Web Multimedia Kuala Lumpur, Shahrom Suzanna

Student Works (2000-2009)

Saya di bawah penyeliaan En. Norzaily Mohamed Noor telah memilih tajuk pembangunan laman web multimedia untuk destinasi-destinasi menarik di sekitar Kuala Lumpur. Pakej perisian ini diberi nama Laman Web Multimedia Kuala Lumpur. Ia akan dibangunkan untuk membantu para pelancong dari dalam dan luar negara untuk memperolehi maklumat berkenaan Kuala Lumpur. Untuk menarik minat pengguna dan sebagai salah satu cara mempromosikan laman web ini, perisian Macromedia Flash telah digunakan. Ia merupakan satu perisian multimedia yang terkini di mana pengguna dapat mencapai maklumat dengan lebih mudah. Di antara kelebihan taman web ini ialah memaparkan pelbagai maklumat yang berinformatif kepada pengguna. Para pengguna …

Design And Develop A Generic Cut-Through Switch, Nazaruddin Noraini

Student Works (2000-2009)

Today's advancement in network is related to the advancement of packet switching technology. Switching directs network traffic in an efficient manner – it sends information directly from the port of origin to only its destination port. Without switching, many networks are experiencing bandwidth shortages because of an increase in traffic due to the increased numbers of users, the amount of data transported between client/server applications, and the inefficient traffic patterns of some networks. Transmission of data from one destination to another is unguaranty successful. Sometimes the data will lost or conupted during transmission to destination port. To make data more …

Digital Library Of Thesis: Administration Side, Soo Noan Chew

Student Works (2000-2009)

Currently, the faculty promoted a plan to rethink the way graduate students present their theses. Traditionally, the theses were produced in paper fonn and storing in library. The access of student work through this method still facing a lot of problems including less timely public access to users, shelf space required for storage, no maintenance, resources are not fully used and cost of preparing theses are high. Thus, Digital Library of Theses is proposed to eliminate all the shortcomings mentioned above. Digital Library of Theses (administration side) is a web-based theses administration system for faculty that can cater about 3 …

Webtv, Soon Hing Leong

Student Works (2000-2009)

This graduation project report was a partial requirement of the Bachelor Degree of Information Technology. This project focused on the testing and implementation of streaming multimedia files using multicast and unicast technology through Local Area Network with conserving network resources. It is also an effort being carried out to provide a multimedia and interactive base entertainment system for Faculty of Computer Science and Information Technology. Multimedia has become a popular catchword during the last few years. The idea behind a multimedia network is a single network combining an improving all current technologies that realizes fast and convenient access for the …

V-Faculty, Kee Foo Leong

Student Works (2000-2009)

The technology of graphics is moving to the era of three dimensions (30). In 1970s, people were using the text-based computer system. When the technique of 2D image processing was invented, people changed their system into 2D representation because of its ability to explain more information in only one image. Around 1990s 3D graphics have been pushed out to the market. Soon, people accepted 3D as an advance information representation medium. The most important achievement of 3D technology is the making of virtual reality, which provides human unlimited space and interactivity. The v- Faculty applies the concept of virtual reality …

Lecture On-Line/On-Demand, Siew Ping Foo

Student Works (2000-2009)

The on-line/on-demand lecture broadcasting is an ideal approach to meet the demand of effective and efficient communication for the fast growing web and multimedia technology. Thus, this project, the development of Lecture On-Line/On-Demand (LOL/LOD) broadcasting system provides the common functional components required for broadcasting both real time and not real time lectures. This will have resolved some existing education delivery bottlenecks such as time inconvenience, location dependence, space and tools limitation in the existing systems.Furthermore, there are viewer and administrator modules proposed for the LOL/LOD system. The viewer section allows the user to view, sort, search on-line or on-demand lectures …

Online Counselling Assistant (Oca Ver 1.0), Mohd Zaini Hana Salwani

Student Works (2000-2009)

OCA ver 1.0 adalah sistem pengurusdan pangkalan data berasaskan web yang dibangunkan untuk membantu komunikasi di FSKTM, Universiti Malaya. Ia direka untuk menjanakan interaksi antara pelajar, pensyarah dan tutor melalui web. OCA mempunyai 4 bahagian iaitu Bahagian Pensyarah, Bahagian Pelajar, Bahagian Tutor dan Bahagian Am. OCA yang berdaftar menghanar tugasan jika tutor atau lecture telah ,emdaftarkan matapelajaran atau tugasan tersebut memuat turun (download) nota jika nota telah dimuat naik (upload) oleh pensyarah dan melihat markah tugasan jika dibenarkan oleh tutor atau pensyarah. OCA membenarkan pensyarah mengadakan pengurusan mata pelajaran dan tugasan supaya dengan ini nota dapat dimuat naik oleh pensyarah …