Digital Commons Network^™

E-Spatial Technology For Spatial Analysis And Decision Making In Web-Based Land Information Management Systems, James Carswell

Articles

In this paper we describe e-SpatialTM technology, comprising an innovative software solution for deploying integrated web-based spatial applications within Oracle 9i Database environments. The two main components of the solution are the iSMARTTM database development technology and the i-SpatialTM Information Server (iSIS). This technology allows Oracle users to build and deploy both spatially enabled and standard Internet applications without requiring any application-specific GIS source code. It can be deployed on any Oracle supported hardware platform and on any device running a Java Virtual Machine, thus providing full support for wireless, PDAs and other mobile devices. In particular, we describe a …

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 …

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 …

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

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 …

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 …

Optimization Of Amplifier Placements In Switch-Based Optical Networks, Ling Zong, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Wavelength division multiplexing (WDM) offers a solution to the problem of exploiting the large bandwidth on optical links; it is the current favorite multiplexing technology for optical communication networks. Due to the high cost of an optical amplifier, it is desirable to strategically place the amplifiers throughout the network in a way that guarantees that all the signals are adequately amplified while minimizing the total number amplifiers being used. Previous studies all consider a star-based network. This paper demonstrates an original approach for solving the problem in switch-based WDM optical network assuming the traffic matrix is always the permutation of …

Hierarchy-Based Access Control In Distributed Environments, Jean-Camille Birget, Xukai Zou, Guevara Noubir, Byrav Ramamurthy

School of Computing: Conference and Workshop Papers

Access control is a fundamental concern in any system that manages resources, e.g., operating systems, file systems, databases and communications systems. The problem we address is how to specify, enforce, and implement access control in distributed environments. This problem occurs in many applications such as management of distributed project resources, e-newspaper and payTV subscription services.

Starting from an access relation between users and resources, we derive a user hierarchy, a resource hierarchy, and a unified hierarchy. The unified hierarchy is then used to specify the access relation in a way that is compact and that allows efficient queries. It is …

New Sequential And Scalable Parallel Algorithms For Incomplete Factor Preconditioning, David A. Hysom

Computer Science Theses & Dissertations

The solution of large, sparse, linear systems of equations Ax = b is an important kernel, and the dominant term with regard to execution time, in many applications in scientific computing. The large size of the systems of equations being solved currently (millions of unknowns and equations) requires iterative solvers on parallel computers. Preconditioning, which is the process of translating a linear system into a related system that is easier to solve, is widely used to reduce solution time and is sometimes required to ensure convergence. Level-based preconditioning (ILU(ℓ)) has long been used in serial contexts and is widely recognized …

Incorporating Window-Based Passage-Level Evidence In Document Retrieval, Wensi Xi, Richard Xu-Rong, Christopher Soo Guan Khoo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

This study investigated whether document retrieval can be improved if documents are divided into smaller sub-documents or passages and the retrieval score for these passages are incorporated in the final retrieval score for the whole document. The documents were segmented by sliding a window of a certain size across the document and extracting the words displayed each time the window stopped. A retrieval score was calculated for each of the passages extracted and the highest score obtained by a passage of that size was taken as the document’s passage-level score for that window size. A range of window sizes was …

Corba: A Quantitative And Qualitative Comparison Of Industrial Strength, Commercial Corba Orbs For The Java Platform, Michelle Leigh Mckeller

UNF Graduate Theses and Dissertations

In distributed systems design, middleware is a key component. Middleware establishes the communication between a client and server in a multi-tiered architecture. One approach to middleware is implementing the OMG's CORBA standard, through the use of ORBs. Three of the more popular commercially available ORBs are Sun's Java 2 ORB, Borland's VisiBroker for Java, and IONA's Orbix 2000 for Java. The purpose of this graduate project was to compare the three ORBs both quantitatively and qualitatively. The project compares the ORBs quantitatively by measuring the performance of each ORB, in terms of response time. The comparison was done qualitatively by …

Unified Modeling Language: A Complexity Analysis, Keng Siau, Q. Cao

Research Collection School Of Computing and Information Systems

Unified Modeling Language (UML) is the standard visual modeling language for Object Oriented (OO) systems development, but it has been criticized for its complexity, inconsistent semantics, and ambiguous constructs. A set of complexity indices for UML and the nine diagramming techniques in UML was compiled recently. The complexity analysis is formulated based on the number of constructs, associations, roles, and so forth, in a modeling method. We argue that this set of metrics provides an indication of the theoretical complexity of the modeling methods. On the other hand, the theoretical complexity of the modeling methods does not necessarily relate to …

A Framework For Performance And Value Assessment Of E-Business Systems In Corporate Travel Distribution, A.M. Chircu, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

This chapter proposes and illustrates a framework that the authors call the value life cycle for e-commerce systems. Based on recent research results that relate to technology investments in the corporate travel industry and related theoretical and empirical perspectives, the authors lay out the corporate travel e-commerce system solutions value life cycle. The perspective involves estimating the maximum value that that an organization can obtain by implementing an e-commerce system in a specific industry and competitive environment. It also considers multiple factors that act as value contingencies for the implementation process. These create barriers to value accrual and to …

Depth-First Search Embedded Wavelet Algorithm For Hardware Implementation, Li-Minn Ang

Theses: Doctorates and Masters

The emerging technology of image communication over wireless transmission channels requires several new challenges to be simultaneously met at the algorithm and architecture levels. At the algorithm level, desirable features include high coding performance, bit stream scalability, robustness to transmission errors and suitability for content-based coding schemes. At the architecture level, we require efficient architectures for construction of portable devices with small size and low power consumption. An important question is to ask if a single coding algorithm can be designed to meet the diverse requirements. Recently, researchers working on improving different features have converged on a set of coding …

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

CCAC 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 …

Guidelines For Development Of Courses For Delivery Over The Iowa Communications Network, Gary F. Hasman

CCAC Theses and Dissertations

This paper examines the quality of education as it relates to the Iowa Communications Network (ICN). It reviews the literature to determine a working definition of quality that was used to create a list of characteristics desirable in teachers who use technology. A list of such teachers was solicited from three administrative committees of the ICN and from the directors of the state's 15 area education agencies. Four teachers were selected from the list and their approach to creating programs for delivery over the ICN was examined. Personal interviews were used to discover commonalities among the four teachers' approaches to …

A Model To Evaluate The Effect Of Organizational Adaptation, Holly A. H. Handley, Alexander H. Levis

Engineering Management & Systems Engineering Faculty Publications

When an organization’s output declines due to either internal changes or changes in its external environment, it needs to adapt. In order to evaluate the effectiveness of different adaptation strategies on organizational per- formance, an organizational model composed of individual models of a five stage interacting decision maker was designed using an object oriented design approach and implemented as a Colored Petri net. The concept of entropy is used to calculate the total activity value, a surrogate for decision maker workload, based on the functional partition and the adaptation strategy being implemented. The individual decision maker’s total activity is monitored, …

Seaway: A Multi-Agent Decision-Support System For Naval Expeditionary Logistic Operations, Anthony Wood, Kym Jason Pohl, Justin Crawford, Mark Lai, John Fanshier, Ken Cudworth, Tom Tate, Hisham Assal, Shawn Pan, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This report describes work performed by CDM Technologies Inc. in conjunction with the Collaborative Agent Design (CAD) Research Center of California Polytechnic State University (Cal Poly), San Luis Obispo, for the Office of Naval Research (ONR), on the SEAWAY experimental system for planning, gaming and executing maritime logistic operations from a sea base. SEAWAY incorporates three fundamental concepts that distinguish it from existing (i.e., legacy) command and control applications. First, it is a collaborative system in which computer-based agents assist human operators by monitoring, analyzing and reasoning about events in near real-time. Second, SEAWAY includes an ontological model of the …

Software Quality Function Deployment, Xiaoqing Frank Liu

Computer Science Faculty Research & Creative Works

Any product development involves projecting its potential success in achieving its functional and commercial goals. Better quality designs that match customer needs and preferences and integrate other lifecycle issues early in the software development process are more likely to be competitive. Thus, there is significant concern in industry about quality product design, which is addressed by quality function deployment (QFD). QFD uses matrices to organize and relate pieces of data to each other. These matrices are often combined to form a basic tool of QFD, called a House of Quality (HoQ). QFD was developed in the Kobe shipyards as a …

An Efficient And Practical Scheme For Privacy Protection In E-Commerce Of Digital Goods, Feng Bao, Robert H. Deng, Peirong Feng

Research Collection School Of Computing and Information Systems

It is commonly acknowledged that customers’ privacy in electronic commerce should be well protected. The solutions may come not only from the ethics education and legislation, but also from cryptographic technologies. In this paper we propose and analyze a privacy protection scheme for e-commerce of digital goods. The scheme takes cryptography as its technical means to realize privacy protection for online customers. It is efficient in both computational cost and communication cost. It is very practical for real e-commerce systems compared with previous solutions. The cryptographic technique presented in this paper is rather simple. But the scheme has great application …

Control Challenges In Multi-Level Adaptive Video Streaming, Dylan Mcnamee, Charles Krasic, Kang Li, Ashvin Goel, Erik Walthinsen, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Streaming video is one of the fastest-growing applications of the Internet. The Internet’s diversity and dynamism demands that video streams adapt to ensure maximum quality at all times. This paper describes the control challenges we have encountered in the Quasar project’s “multi-level” adaptive streaming video player. We first describe the framework and environment of the player. This framework uses software feedback to control resource allocation as well as the quality of media delivery. We present the control challenges raised by our framework, which include horizontal and vertical feedback composition, difficult to model systems, and unpredictable, non-linear actuators. We describe some …

Generalized Tcp Congestion Avoidance And Its Effect On Bandwidth Sharing And Variability, Archan Misra, John Baras, Teunis Ott

Research Collection School Of Computing and Information Systems

To model possible suggested changes in TCP window adaptation in response to randomized feedback, such as ECN (explicit congestion notification), we formulate a generalized version of the TCP congestion avoidance algorithm. We first consider multiple such generalized TCP flows sharing a bottleneck buffer under the assured service model and use a fixed point technique to obtain the mean window sizes and throughputs for the TCP flows, To further study how changes in the adaptation algorithm affect the variability in the throughput, we use an analytical-cum-numerical technique to derive the window distribution (and related statistics) of a single generalized flow under …

Java On Networks Of Workstations (Javanow): A Parallel Computing Framework Inspired By Linda And The Message Passing Interface (Mpi), George K. Thiruvathukal, Phil M. Dickens, Shahzad Bhatti

Computer Science: Faculty Publications and Other Works

Networks of workstations are a dominant force in the distributed computing arena, due primarily to the excellent price/performance ratio of such systems when compared to traditionally massively parallel architectures. It is therefore critical to develop programming languages and environments that can help harness the raw computational power available on these systems. In this article, we present JavaNOW (Java on Networks of Workstations), a Java‐based framework for parallel programming on networks of workstations. It creates a virtual parallel machine similar to the MPI (Message Passing Interface) model, and provides distributed associative shared memory similar to the Linda memory model but with …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 3, November 2000, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

A Survey Of Context-Aware Mobile Computing Research, Guanling Chen, David Kotz

Computer Science Technical Reports

Context-aware computing is a mobile computing paradigm in which applications can discover and take advantage of contextual information (such as user location, time of day, nearby people and devices, and user activity). Since it was proposed about a decade ago, many researchers have studied this topic and built several context-aware applications to demonstrate the usefulness of this new technology. Context-aware applications (or the system infrastructure to support them), however, have never been widely available to everyday users. In this survey of research on context-aware systems and applications, we looked in depth at the types of context used and models of …

Toward Automated Abstraction For Protocols On Branching Networks, Michael D. Jones, Ganesh Gopalakrishnan

Faculty Publications

We have used various manual abstraction techniques to formally verify a transaction ordering property for an IO protocol over bus/bridge networks. In the context of network protocol verification, an abstraction is needed to reduce the unbounded number of network configurations to a small number of representative networks that can be checked using algorithmic methods. The manually derived abstraction was both brittle and difficult to validate. In this report, we discuss the need for abstraction techniques in the formal verification of protocols over networks and present our recent efforts to create an automatic abstraction technique for network protocols using predicate abstraction …

Gasturbnlab Simulation Of Instability In A Gas Turbine, A. C. Catlin, S. Fleeter, Elias N. Houstis, John R. Rice, C. Zhou

Department of Computer Science Technical Reports

No abstract provided.

Using 'Drop-Biasing' To Stabilize The Occupancy Of Random-Drop Queues With Tcp Traffic, Archan Misra, Teunis Ott, John Baras

Research Collection School Of Computing and Information Systems

The paper describes how the use of ‘drop-biasing’, a technique to control the distribution of the gap between consecutive packet losses in random drop queues (such as RED) can be used to reduce the variability of the queue occupancy with TCP traffic. Reducing the variance of the queue occupancy reduces delay jitter for buffered packets, as well as decreases the likelihood of buffer underflow. We find that modifying the packet drop probabilities to ensure a minimum separation between consecutive packet drops serves to decrease the variability in the queue occupancy. This is really achieved as a result of the increased …

Extensible Mpeg-4 Textual Format (Xmt), Michelle Kim, Steve Wood, Lai-Tee Cheok

Research Collection School Of Computing and Information Systems

This paper describes the Extensible MPEG-4 Textual format (XMT), a framework for representing MPEG-4 scene description using a textual syntax. The XMT allows the content authors to exchange their content with other authors, tools or service providers, and facilitates interoperability with both the X3D, developed by the Web3D consortium, and the Synchronized Multimedia Integration Language (SM1L) from the W3C consortium.

Automated Systematic Testing For Constraint-Based Interactive Services, Patrice Godefroid, Lalita Jategaonkar Jagadeesan, Radha Jagadeesan, Konstantin Laufer

Computer Science: Faculty Publications and Other Works

Constraint-based languages can express in a concise way the complex logic of a new generation of interactive services for applications such as banking or stock trading, that must support multiple types of interfaces for accessing the same data. These include automatic speech-recognition interfaces where inputs may be provided in any order by users of the service. We study in this paper how to systematically test event-driven applications developed using such languages. We show how such applications can be tested automatically, without the need for any manually-written test cases, and effi- ciently, by taking advantage of their capability of taking unordered …