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Articles 52501 - 52530 of 58244

Full-Text Articles in Physical Sciences and Mathematics

Scheduling Processing Resources In Programmable Routers, Prashanth Pappu, Tilman Wolf Jan 2001

Scheduling Processing Resources In Programmable Routers, Prashanth Pappu, Tilman Wolf

All Computer Science and Engineering Research

To provide flexibility in deploying new protocols and services, general-purpose processing engines are being placed in the datapath of routers. Such network processors are typically simple RISC multiprocessors that perform forwarding and custom application processing of packets. The inherent unpredictability of execution time of arbitrary instruction code poses a significant challenge in providing QoS guarantees for data flows that compete for such processing resources in the network. However, we show that network processing workloads are highly regular and predictable. Using estimates of execution times of various applications on packets of given lengths, we provide a method for admission control and …


Scalable Ip Lookup For Programmable Routers, David E. Taylor, John W. Lockwood, Todd Sproull, David B. Parlour Jan 2001

Scalable Ip Lookup For Programmable Routers, David E. Taylor, John W. Lockwood, Todd Sproull, David B. Parlour

All Computer Science and Engineering Research

Continuing growth in optical link speeds places increasing demands on the performance of Internet routers, while deployment of embedded and distributed network services imposes new demands for flexibility and programmability. IP adress lookup has become a significant performance bottleneck for the highest performance routers. New commercial products utilize dedicated Content Addressable Memory (CAM) devides to achieve high lookup speeds. This paper describes an efficient, scalable lookup engine design, able to achieve high-performance with the use of a small portion of a reconfigurable logic device and a commodity Random Access Memory (RAM) device. Based on Eatherton's Tree Bitmap algorithm [1] the …


Evaluation Of Motion-Jpeg2000 For Video Processing, Wei Yu, Ruibiao Qiu, Jason Fritts Jan 2001

Evaluation Of Motion-Jpeg2000 For Video Processing, Wei Yu, Ruibiao Qiu, Jason Fritts

All Computer Science and Engineering Research

The new ISO/ITU-T standard for still image coding, JPEG2000, has been shown to provide superior coding efficiency to the previous standard, JPEG. Because of the superb performance of JPEG2000, it is reasonable to argue that Motion-JPEG2000, the corresponding moving picture coding standard of JPEG2000, has equally outstanding performance. However, there has not been a sufficient performance evaluation of Motion-JPEG2000. To this end, we have studied the potential of Motion-JPEG2000 for video processing. Our experiments show that Motion-JPEG2000 provides high compression performance, strong error resilience, and good perceptual image quality. Together with a rich set of features inherited from JPEG2000, Motion-JPEG2000 …


Services Provision In Ad Hoc Networks, Radu Handorean, Gruia-Catalin Roman Jan 2001

Services Provision In Ad Hoc Networks, Radu Handorean, Gruia-Catalin Roman

All Computer Science and Engineering Research

The client-server model continues to dominate distributed computing with increasingly more flexible variants being deployed. Many are centered on the notion of discovering services at run time and on allowing any system component to act as a service provider. The result is a growing reliance on the service registration and discovery mechanisms. This paper addresses the issue of facilitating such service provision capabilities in the presence of (logical and physical) mobility exhibited by applications executing over ad hoc networks. The solution being discussed entailes a new kind of service model, which we were able to build as an adaption layer …


Placing Servers For Session-Oriented Services, Sumi Choi, Yuval Shavitt Jan 2001

Placing Servers For Session-Oriented Services, Sumi Choi, Yuval Shavitt

All Computer Science and Engineering Research

The provisioning of dynamic forms of services is becoming the main stream of today's network. In this paper, we focus on services assisted by network servers and different forms of associated sessions. We identify two types of services: transparent, where the session is unaware of the server location, and configurable, where the sessions need to be configured to use their closest server. For both types we formalize the problem of optimally placing network servers and introduce approximated solutions. We present simulation result of approximations and heuristics. We also solve the location problem optimally for a special topology. We show, through …


Relationship Between Two Generalized Images For Discrete And Differential Camera Motions, Robert Pless Jan 2001

Relationship Between Two Generalized Images For Discrete And Differential Camera Motions, Robert Pless

All Computer Science and Engineering Research

The recent popularity of catadioptic and multi-camera imaging systems indicates a need to create formal models for general, non-perspective camera geometries. Development of algorithmic tools for interpreting images from a generalized camera model will lead to a better understanding of how to design camera systems for particular tasks. Here we define the corollary to epi-polar constraints for standard cameras - the relationship between two images of a scene taken by generalized cameras from viewpoints related by discrete or differential motions.


Embedding Images In Non-Flat Spaces, Robert Pless Jan 2001

Embedding Images In Non-Flat Spaces, Robert Pless

All Computer Science and Engineering Research

Multi-dimensional scaling is an analysis tool which transforms pairwise distances between points to an embedding of points in space which are consistent with those distances. Two recent techniques in statistical patter recognition, locally linear embedding (LLE) and Isomap, give a mechanism for finding the structure underlying point sets for which comparisons or distances are only meaningful between nearby points. We give a direct method to extend the embedding algorithm to new topologies, finding the optimal embedding of points whose geodesic distance on a surface mathes the given pairwise distance measurements. Surfaces considered include spheres, cylinders, tori, and their higher dimensional …


An Efficient Quality Scalable Motion-Jpeg2000 Transmission Scheme, Ruibiao Qiu, Wei Yu Jan 2001

An Efficient Quality Scalable Motion-Jpeg2000 Transmission Scheme, Ruibiao Qiu, Wei Yu

All Computer Science and Engineering Research

Video application over the Internet are getting increasingly popular because of the explosive growth of the Internet. However, video packets loss due to network congestions can degrade the video quality substantially. In this paper, we propose a transmission scheme for Motion-JPEG2000. It can be implemented in an active network environment efficiently. Our simulation shows that our scheme gracefully adapts to network congestion and improves the quality of video transmission in congested IP networks.


Legends As A Device For Interacting With Visualizations, Mihail E. Tudoreanu, Eileen Kraemer Jan 2001

Legends As A Device For Interacting With Visualizations, Mihail E. Tudoreanu, Eileen Kraemer

All Computer Science and Engineering Research

Users and developers of visualization tools must deal with the problem of specifying what information to show and how to represent it. Typically, the user's focus of interest will change over time, and the specifications must change with the user's interests. Techniques for the simple, direct, and intuitive creation and refinement of these specifications can be useful. In this paper we show how legends, a natural element of graphical displays, may be used as a direct and unobstrusive interaction device through which users may interactively specify new visualizations and animations.


Comparison Of Student Performance And Attitude In A Lecture Class To Student Performance And Attitude In A Telecourse And A Web-Based Class, William J. Ryan Jan 2001

Comparison Of Student Performance And Attitude In A Lecture Class To Student Performance And Attitude In A Telecourse And A Web-Based Class, William J. Ryan

CCE Theses and Dissertations

Increasing numbers of students are returning to school and choosing alternatives to the lecture method of instruction. Using technology to reach students is a solution colleges and universities are evaluating and implementing with the goal of increasing enrollment and reducing the cost of instruction. This research examines the impact two technology-based delivery systems have on the student's learning experience compared with an equivalent classroom-based instructional method.

Academic institutions are being asked to respond to the rapid changes faced by the communities they serve especially as current workers return to join new students in obtaining knowledge and skills needed in today's …


Reorganizing Web Sites Based On User Access Patterns, Yongjian Fu, Mario Creado, Chunhua Ju Jan 2001

Reorganizing Web Sites Based On User Access Patterns, Yongjian Fu, Mario Creado, Chunhua Ju

Computer Science Faculty Research & Creative Works

In this paper, an approach for reorganizing Web sites based on user access patterns is proposed. The approach consists of three steps: preprocessing, page classification, and site reorganization. In preprocessing, pages on a Web site are processed to create an internal representation of the site, and page access information of its users is extracted from its server log. In page classification, the Web pages on the site are classified into two categories, index pages and content pages, based on the page access information. After the pages are classified, in site reorganization, the Web site is examined to find better ways …


Graduate School Of Computer And Information Sciences--Master Of Science Degree Programs 2001-2003, Nova Southeastern University Jan 2001

Graduate School Of Computer And Information Sciences--Master Of Science Degree Programs 2001-2003, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.


Learning Recursive Functions Refutably, Sanjay Jain, Efim Kinber, Rolf Wiehagen, Thomas Zeugmann Jan 2001

Learning Recursive Functions Refutably, Sanjay Jain, Efim Kinber, Rolf Wiehagen, Thomas Zeugmann

School of Computer Science & Engineering Faculty Publications

Learning of recursive functions refutably means that for every recursive function, the learning machine has either to learn this function or to refute it, i.e., to signal that it is not able to learn it. Three modi of making precise the notion of refuting are considered. We show that the corresponding types of learning refutably are of strictly increasing power, where already the most stringent of them turns out to be of remarkable topological and algorithmical richness. All these types are closed under union, though in different strengths. Also, these types are shown to be different with respect to their …


Rate-Matching Packet Scheduler For Real-Rate Applications, Kang Li, Jonathan Walpole, Dylan Mcnamee, Calton Pu, David Steere Jan 2001

Rate-Matching Packet Scheduler For Real-Rate Applications, Kang Li, Jonathan Walpole, Dylan Mcnamee, Calton Pu, David Steere

Computer Science Faculty Publications and Presentations

A packet scheduler is an operating system component that controls the allocation of network interface bandwidth to outgoing network flows. By deciding which packet to send next, packet schedulers not only determine how bandwidth is shared among flows, but also play a key role in determining the rate and timing behavior of individual flows. The recent explosion of rate and timing-sensitive flows, particularly in the context of multimedia applications, has focused new interest on packet schedulers. Next generation packet schedulers must not only ensure separation among flows and meet real-time performance constraints, they must also support dynamic fine-grain reallocation of …


Combining Multiple Representations For Pen-Based Handwritten Digit Recognition, Fevzi̇ Ali̇moğlu, Ethem Alpaydin Jan 2001

Combining Multiple Representations For Pen-Based Handwritten Digit Recognition, Fevzi̇ Ali̇moğlu, Ethem Alpaydin

Turkish Journal of Electrical Engineering and Computer Sciences

We investigate techniques to combine multiple representations of a handwritten digit to increase classification accuracy without significantly increasing system complexity or recognition time. In pen-based recognition, the input is the dynamic movement of the pentip over the pressure sensitive tablet. There is also the image formed as a result of this movement. On a real-world database of handwritten digits containing more than 11,000 handwritten digits, we notice that the two multi-layer perceptron (MLP) based classifiers using these representations make errors on different patterns implying that a suitable combination of the two would lead to higher accuracy. We implement and compare …


Fuzzy Modeling Approach For Integrated Assessments Using Cultural Theory, Adnan Yazici, Fred E. Petry, Curt Pendergraft Jan 2001

Fuzzy Modeling Approach For Integrated Assessments Using Cultural Theory, Adnan Yazici, Fred E. Petry, Curt Pendergraft

Turkish Journal of Electrical Engineering and Computer Sciences

It has already been noted that the accurate prediction of societal responses requires the use of a formal model based on some social or cultural taxonomy. One such taxonomic candidate is Cultural Theory (CT). CT argues that all societies, irrespective of time or place, are informed by their underlying worldviews, which must be more or less Hierarchic, more or less Individualistic, more or less Egalitarian, and more or less Fatalistic. This approach appears to have a potential for cross-temporal and spatial comparisons that makes it a particularly attractive instrument for a study of the human dimensions of global climate change. …


A More Efficient Design And Implementation Of Cal Programs In Natural Science Using Object-Oriented Technology, Jurgen Friedrich Jan 2001

A More Efficient Design And Implementation Of Cal Programs In Natural Science Using Object-Oriented Technology, Jurgen Friedrich

Turkish Journal of Electrical Engineering and Computer Sciences

With the amount and complexity of science topics and applications increasing, the need for appropriate and effective science education is constantly growing. Computer-based education is very promising to help both teachers and learners in their difficult task, which involves complex psychological processes. This complexity is reflected in high demands on the design and implementation methods used to create computer-assisted learning (CAL) programs. Due to their concepts, flexibility, maintainability and extended library resources, object-oriented technology (OOT) is very suitable to producing this type of pedagogical tool. The introduced approach is demonstrated by a basketball simulation program for instruction in Newtonian mechanics …


Smart Objects And Open Archives, Michael L. Nelson, Kurt Maly Jan 2001

Smart Objects And Open Archives, Michael L. Nelson, Kurt Maly

Computer Science Faculty Publications

Within the context of digital libraries (DLs), we are making information objects "first-class citizens". We decouple information objects from the systems used for their storage and retrieval, allowing the technology for both DLs and information content to progress independently. We believe dismantling the stovepipe of "DL-archive-content" is the first step in building richer DL experiences for users and insuring the long-term survivability of digital information. To demonstrate this partitioning between DLs, archives and information content, we introduce "buckets": aggregative, intelligent, object-oriented constructs for publishing in digital libraries. Buckets exist within the "Smart Object, Dumb Archive" (SODA) DL model, which promotes …


Arc - An Oai Service Provider For Digital Library Federation, Xiaoming Liu, Kurt Maly, Mohammad Zubair, Michael L. Nelson Jan 2001

Arc - An Oai Service Provider For Digital Library Federation, Xiaoming Liu, Kurt Maly, Mohammad Zubair, Michael L. Nelson

Computer Science Faculty Publications

The usefulness of the many on-line journals and scientific digital libraries that exist today is limited by the inability to federate these resources through a unified interface. The Open Archive Initiative (OAI) is one major effort to address technical interoperability among distributed archives. The objective of OAI is to develop a framework to facilitate the discovery of content in distributed archives. In this paper, we describe our experience and lessons learned in building Arc, the first federated searching service based on the OAI protocol. Arc harvests metadata from several OAI compliant archives, normalizes them, and stores them in a search …


Buckets: Smart Objects For Digital Libraries, Michael L. Nelson Jan 2001

Buckets: Smart Objects For Digital Libraries, Michael L. Nelson

Computer Science Faculty Publications

Current discussion of digital libraries (DLs) is often dominated by the merits of the respective storage, search and retrieval functionality of archives, repositories, search engines, search interfaces and database systems. While these technologies are necessary for information management, the information content is more important than the systems used for its storage and retrieval. Digital information should have the same long-term survivability prospects as traditional hardcopy information and should be protected to the extent possible from evolving search engine technologies and vendor vagaries in database management systems. Information content and information retrieval systems should progress on independent paths and make limited …


Efficient Algorithms For Graphs With Few P-4’S, Luitpold Babel, Ton Kloks, Jan Kratochvíl, Dieter Kratsch, Kaiko Müller, Stephan Olariu Jan 2001

Efficient Algorithms For Graphs With Few P-4’S, Luitpold Babel, Ton Kloks, Jan Kratochvíl, Dieter Kratsch, Kaiko Müller, Stephan Olariu

Computer Science Faculty Publications

We show that a large variety of NP-complete problems can be solved efficiently for graphs with 'few' P4's. We consider domination problems (domination, total domination, independent domination. connected domination and dominating clique), the Steiner tree problem, the vertex ranking problem, the pathwidth problem, the path cover number problem, the hamiltonian circuit problem, the list coloring problem and the precoloring extension problem. We show that all these problems can be solved in linear time for the class of (q,q - 4)-graphs, for every fixed q. These are graphs for which no set of at most q. vertices induces more …


Video Compression Using Wavelets And Hierarchical Motion Estimation, Andrew Peter Byrne Jan 2001

Video Compression Using Wavelets And Hierarchical Motion Estimation, Andrew Peter Byrne

Theses : Honours

This thesis investigates the benefits and the significant compression that can be obtained from data that has been decomposed using a wavelet transform. A video compression algorithm was developed that employs the wavelet transform and a hierarchical motion estimation algorithm which itself utilises benefits of the wavelet transform. Using MATLAB, a popular software tool for matrix based computation and analysis, several functions were developed which together formed the video compression algorithm. A variety of tests were conducted on a sample video sequence to ascertain the strengths and weaknesses of the techniques employed. The results, although not the same as the …


Storage Free Terrain Simulation, Warren Creemers Jan 2001

Storage Free Terrain Simulation, Warren Creemers

Theses : Honours

Landscape visualisation is the process of recreating a natural environment and displaying it in an interactive graphical simulation. To do this a terrain is displayed together with accompanying plant life and other objects. Present landscape visualisation software is capable in theory of displaying very detailed and large landscapes. The software is also in theory capable of simulating environments with thousands if not millions of individually structured plants. In practice though, the simulation of such landscapes requires such a large amount of storage space that it is not achievable on personal computers. Even storing small landscapes with a moderate amount plant …


The Design Of 3d Cyberspace As User Interface: Advantages And Limitations, Maria Borisovna Quick Jan 2001

The Design Of 3d Cyberspace As User Interface: Advantages And Limitations, Maria Borisovna Quick

Theses : Honours

Virtual reality propagandists, technologists and the Internet community have long debated the issue of the usability of online three-dimensional (3D) environments. A lot of work was published about the benefits of 3D spaces for human-computer interaction and information visualisation due to their realism (Anders, Kalawsky, Crossley, Davies, McGrath, Rejman-Greene, 1998, Hamit, 1993, Heim, 1992, Aukstakalnis, Blatner, Roth, 1992). This topic also receives continuous industry support including standardisation of Virtual Reality Modeling Language ( VRML, VRML Consortium, 1997) and the more recent Macromedia & Intel alliance "to bring web 3D to the mainstream" (200 1, Intel Corporation). The actual implementation …


Bluetooth Software On Linux, Wireless Hand-Held Devices, Teck Khoon Low Jan 2001

Bluetooth Software On Linux, Wireless Hand-Held Devices, Teck Khoon Low

Theses : Honours

In order to enable existing computers (non-Bluetooth ready) to connect to a Bluetooth piconet, a Bluetooth hardware device comprising of the Radio antenna, the baseband and control circuit is used. The digital portion of this device is also known as a Host Controller, HC. In the traditional communication lingo, the Bluetooth Hardware functions, as the Data Communication Equipment (DCE) while the Host is the Data terminal Equipment (DTE). This report discusses the theory and implementation of the communication protocol between the Host and the Host Controller, enabling communication between the computer and the Bluetooth hardware


Meeting The Challenge Of Dynamic User Requirements Using Data-Driven Techniques On A 4gl-Database Environment, Christopher Bolan Jan 2001

Meeting The Challenge Of Dynamic User Requirements Using Data-Driven Techniques On A 4gl-Database Environment, Christopher Bolan

Theses : Honours

Accompanying the ever-growing reliance on computers within contemporary organisations, the task of software maintenance is, increasingly, becoming a resource burden. The author has identified that there is a need for proven techniques to allow the modelling of flexible/changing user requirement, to enable systems to cope with requirements creep without suffering major code change and associated down-time from rebuilds of the database. This study ascertains the applicability of extension to current data modelling techniques that allows innate flexibility within the data model. The extension of the data model is analysed for potential benefits in the provision of such a dynamic/flexible base …


Entropy Generation Method To Quantify Thermal Comfort, S. C. Boregowda, S. N. Tiwari, S. K. Chaturvedi Jan 2001

Entropy Generation Method To Quantify Thermal Comfort, S. C. Boregowda, S. N. Tiwari, S. K. Chaturvedi

Mechanical & Aerospace Engineering Faculty Publications

The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a …


Performance Of Genetic Algorithms For Data Classification, Matthew E. Stine Jan 2001

Performance Of Genetic Algorithms For Data Classification, Matthew E. Stine

Honors Theses

In today's world, the amount of raw data archived across multiple distinct domains is growing at an exponential rate. "Data Mining" is a continuously evolving family of processes by which individuals extract useful information from these data. Classification is one of these processes, and is the construction of varying types of descriptive models from labeled data objects, for the purpose of predicting the label of those objects with unknown labels. The construction of these modules is often adversely affected by the presence of incorrect values or outlier values within the data, a phenomenon known as noise. The original motivation of …


A Market-Based Model For Resource Allocation In Agent Systems, Jonathan Bredin, David Kotz, Daniela Rus Jan 2001

A Market-Based Model For Resource Allocation In Agent Systems, Jonathan Bredin, David Kotz, Daniela Rus

Dartmouth Scholarship

In traditional computational systems, resource owners have no incentive to subject themselves to additional risk and congestion associated with providing service to arbitrary agents, but there are applications that benefit from open environments. We argue for the use of markets to regulate agent systems. With market mechanisms, agents have the abilities to assess the cost of their actions, behave responsibly, and coordinate their resource usage both temporally and spatially. \par We discuss our market structure and mechanisms we have developed to foster secure exchange between agents and hosts. Additionally, we believe that certain agent applications encourage repeated interactions that benefit …


Adaptive Web Sites By Web Usage Mining, Mario Rodney Creado Jan 2001

Adaptive Web Sites By Web Usage Mining, Mario Rodney Creado

Masters Theses

The World Wide Web has become a very popular marketing medium during the recent years. Many businesses use it extensively to publicize their products. Initially it began with static web sites. However as web sites got bigger and better, their maintenance became problematic. Just as business strategies change, so also will the orgainization of their web sites change. Hence the need of the hour is an adaptive web site (i.e. a web site that can organize itself based upon its usage). For this purpose, web usage mining techniques are used. The characteristics of the user's activity on the web site …