Digital Commons Network^™

Using Real Options Analysis For Evaluating Uncertain Investments In Information Technology: Insights From The Icis 2001 Debate, Paul P. Tallon, Robert J. Kauffman, Henry C. Lucas, Andrew B. Whinston, Kevin Zhu

Research Collection School Of Computing and Information Systems

Business and information systems (IS) executives continue to grapple with issues of risk and uncertainty in evaluating investments in information technology (IT). Despite the use of net present value (NPV) and other investment appraisal techniques, executives are often forced to rely on instinct when finalizing IT investment decisions. Recognizing the shortcomings of NPV, real options analysis has been suggested as an alternative approach, one that considers the risks associated with an investment while recognizing the ability of corporations to defer an investment until a later period or to make a partial investment instead. Responding to a growing interest in real …

Video Indexing And Retrieval Techniques Using Novel Approaches To Video Segmentation, Characterization, And Similarity Matching, Waleed Ezzat Farag

Computer Science Theses & Dissertations

Multimedia applications are rapidly spread at an ever-increasing rate introducing a number of challenging problems at the hands of the research community, The most significant and influential problem, among them, is the effective access to stored data. In spite of the popularity of keyword-based search technique in alphanumeric databases, it is inadequate for use with multimedia data due to their unstructured nature. On the other hand, a number of content-based access techniques have been developed in the context of image indexing and retrieval; meanwhile video retrieval systems start to gain wide attention, This work proposes a number of techniques constituting …

Controlling Web Query Execution In A Web Warehouse, Sanjay Kumar Madria, Sourav S. Bhowmick

Computer Science Faculty Research & Creative Works

Most of the contemporary Web query systems have limited capabilities in controlling Web query execution. Such query facility is important as it gives us an opportunity to optimize the evaluation of a Web query. We address this issue in the context of our Web warehousing system called WHOWEDA (Warehouse Of Web Data). Specifically, we investigate different types of constraints (related to query execution) which may be imposed on a Web query such as number of query results, time of execution, restrict the evaluation of a query to specified set of Web sites, etc. An important feature of our approach is …

A Distributed Discrete-Time Neural Network Architecture For Pattern Allocation And Control, A.T. Chronopoulos, Jagannathan Sarangapani

Computer Science Faculty Research & Creative Works

No abstract provided.

Adaptive Critic-Based Neural Network Controller For Uncertain Nonlinear Systems With Unknown Deadzones, Pingan He, Jagannathan Sarangapani, S. N. Balakrishnan

Electrical and Computer Engineering Faculty Research & Creative Works

A multilayer neural network (NN) controller in discrete-time is designed to deliver a desired tracking performance for a class of nonlinear systems with input deadzones. This multilayer NN controller has an adaptive critic NN architecture with two NNs for compensating the deadzone nonlinearity and a third NN for approximating the dynamics of the nonlinear system. A reinforcement learning scheme in discrete-time is proposed for the adaptive critic NN deadzone compensator, where the learning is performed based on a certain performance measure, which is supplied from a critic. The adaptive generating NN rejects the errors induced by the deadzone whereas a …

Federating Heterogeneous Digital Libraries By Metadata Harvesting, Xiaoming Liu

Computer Science Theses & Dissertations

This dissertation studies the challenges and issues faced in federating heterogeneous digital libraries (DLs) by metadata harvesting. The objective of federation is to provide high-level services (e.g. transparent search across all DLs) on the collective metadata from different digital libraries. There are two main approaches to federate DLs: distributed searching approach and harvesting approach. As the distributed searching approach replies on executing queries to digital libraries in real time, it has problems with scalability. The difficulty of creating a distributed searching service for a large federation is the motivation behind Open Archives Initiatives Protocols for Metadata Harvesting (OAI-PMH). OAI-PMH supports …

A Policy-Based Resource Brokering Environment For Computational Grids, Ahmed Hamdan Al-Theneyan

Computer Science Theses & Dissertations

With the advances in networking infrastructure in general, and the Internet in particular, we can build grid environments that allow users to utilize a diverse set of distributed and heterogeneous resources. Since the focus of such environments is the efficient usage of the underlying resources, a critical component is the resource brokering environment that mediates the discovery, access and usage of these resources. With the consumer's constraints, provider's rules, distributed heterogeneous resources and the large number of scheduling choices, the resource brokering environment needs to decide where to place the user's jobs and when to start their execution in a …

Geometric Integrators For Hamiltonian Pdes, Dmitry Karpeev

Computer Science Theses & Dissertations

We consider methods for systematic construction of algorithms for a class of time-dependent PDEs with Hamiltonian structure. These systems possess phase space geometry and constants of the motion that need to be preserved by the integration algorithm to reflect the qualitative features of the system.

We exploit the structure of Hamiltonian systems, in particular their variational formulation based on a Lagrangian, and the dual covariant formulation, to expose the geometric features of the system that have natural analogs when discretized. We emphasize the local space-time approach to the constructions, making them amenable to parallelization and preconditioning using domain decomposition methods, …

Performance Modeling And Prediction For The Scalable Solution Of Partial Differential Equations On Unstructured Grids, Dinesh Kumar Kaushik

Computer Science Theses & Dissertations

This dissertation studies the sources of poor performance in scientific computing codes based on partial differential equations (PDEs), which typically perform at a computational rate well below other scientific simulations (e.g., those with dense linear algebra or N-body kernels) on modern architectures with deep memory hierarchies. We identify that the primary factors responsible for this relatively poor performance are: insufficient available memory bandwidth, low ratio of work to data size (good algorithmic efficiency), and nonscaling cost of synchronization and gather/scatter operations (for a fixed problem size scaling). This dissertation also illustrates how to reuse the legacy scientific and engineering software …

Multimedia Tools For The Creation Of Online Learning Materials : A Critique, Victor Augustine Udosen

World Maritime University Dissertations

No abstract provided.

Application Of Extensive Markup Language (Xml) For Shipping Companies, Bala Vithoba Meshram

World Maritime University Dissertations

No abstract provided.

Open Source Software: A History, David Bretthauer

Published Works

In the 30 years from 1970-2000, open source software began as an assumption without a name or a clear alternative. It has evolved into a sophisticated movement which has produced some of the most stable and widely used software packages ever produced. This paper traces the evolution of three operating systems: GNU, BSD, and Linux, as well as the communities which have evolved with these systems and some of the commonly-used software packages developed using the open source model. It also discusses some of the major figures in open source software, and defines both “free software” and “open source software.”

Night Out Itinerary Creator, Jennifer Hood

Honors Capstone Projects and Theses

No abstract provided.

Meeting Medical Terminology Needs: The Ontology-Enhanced Medical Concept Mapper, Gondy Leroy, Hsinchun Chen

CGU Faculty Publications and Research

This paper describes the development and testing of the Medical Concept Mapper, a tool designed to facilitate access to online medical information sources by providing users with appropriate medical search terms for their personal queries. Our system is valuable for patients whose knowledge of medical vocabularies is inadequate to find the desired information, and for medical experts who search for information outside their field of expertise. The Medical Concept Mapper maps synonyms and semantically related concepts to a user's query. The system is unique because it integrates our natural language processing tool, i.e., the Arizona (AZ) Noun Phraser, with human-created …

Meeting Medical Terminology Needs: The Ontology-Enhanced Medical Concept Mapper, Gondy Leroy, Hsinchun Chen

CGU Faculty Publications and Research

This paper describes the development and testing of the Medical Concept Mapper, a tool designed to facilitate access to online medical information sources by providing users with appropriate medical search terms for their personal queries. Our system is valuable for patients whose knowledge of medical vocabularies is inadequate to find the desired information, and for medical experts who search for information outside their field of expertise. The Medical Concept Mapper maps synonyms and semantically related concepts to a user's query. The system is unique because it integrates our natural language processing tool, i.e., the Arizona (AZ) Noun Phraser, with human-created …

Slowstart Congestion Control For Fine-Grained Layered Multicast, Khalid Shaheen

Archived Theses and Dissertations

No abstract provided.

Learning From Linux, Sourav Mukherji

IIMB Management Review

Conventional wisdom on knowledge management deems organisations as essential vehicles for collaborative knowledge creation but here the entire process of knowledge creation takes place outside the boundary of any formal hierarchical organisation, creating a paradox for knowledge management. An attempt is made here to analyse the Linux development process to help resolve this paradox, and in the process, provide some insights Award Winning Student Essay Learning from Linux for organisational knowledge management.

Deploying Integrated Web-Based Spatial Applications Within An Oracle Database Environment, James Carswell

Conference papers

In this paper, we describe the architectural and functional characteristics of e-Spatial™ technology, comprising an innovative software package that represents a timely alternative to traditional and complex proprietary GIS application packages. The two main components of the package, developed by e- Spatial Solutions, are the iSMART™ database development technology and the i-Spatial™ Information Server (iSIS), both implemented within an Oracle 9i Spatial database environment. This technology allows users to build and deploy spatially enabled or standard Internet applications without requiring any application-specific source code. It can be deployed on any Oracle supported hardware platform and on any device that supports …

Mobile-Agent Versus Client/Server Performance: Scalability In An Information-Retrieval Task, Robert S. Gray, David Kotz, Ronald A. Peterson, Joyce Barton, Daria Chacon, Peter Gerken, Martin Hofmann, Jeffrey Bradshaw, Maggie Breedy, Renia Jeffers, Niranjan Suri

Dartmouth Scholarship

Building applications with mobile agents often reduces the bandwidth required for the application, and improves performance. The cost is increased server workload. There are, however, few studies of the scalability of mobile-agent systems. We present scalability experiments that compare four mobile-agent platforms with a traditional client/server approach. The four mobile-agent platforms have similar behavior, but their absolute performance varies with underlying implementation choices. Our experiments demonstrate the complex interaction between environmental, application, and system parameters.

Dual Heuristic Programming For Fuzzy Control, George G. Lendaris, Thaddeus T. Shannon, Larry J. Schultz, Steven Hutsell, Alec Rogers

Complex Systems Faculty Publications and Presentations

Overview material for the Special Session (Tuning Fuzzy Controllers Using Adaptive Critic Based Approximate Dynamic Programming) is provided. The Dual Heuristic Programming (DHP) method of Approximate Dynamic Programming is described and used to the design a fuzzy control system. DHP and related techniques have been developed in the neurocontrol context but can be equally productive when used with fuzzy controllers or neuro-fuzzy hybrids. This technique is demonstrated by designing a temperature controller for a simple water bath system. In this example, we take advantage of the TSK model framework to initialize the tunable parameters of our plant model with reasonable …

Fast Focal Length Solution In Partial Panoramic Image Stitching, William A. Barrett, Kirk L. Duffin

Faculty Publications

Accurate estimation of effective camera focal length is crucial to the success of panoramic image stitching. Fast techniques for estimating the focal length exist, but are dependent upon a close initial approximation or the existence of a full circle panoramic image sequence. Numerical solutions of the focal length demonstrate strong coupling between the focal length and the angles used to position each component image about the common spherical center. This paper demonstrates that parameterizing panoramic image positions using spherical arc length instead of angles effectively decouples the focal length Ji.om the image position. This new parameterization does not require an …

Characteristics Of Erp Software Maintenance: A Multiple Case Study, Fiona Fui-Hoon Nah, Silvana Faja, Teuta Cata

Research Collection School Of Computing and Information Systems

A multiple case study approach was employed to identify maintenance activities pertaining to enterprise resource planning (ERP) implementation, classify them into maintenance categories, and assess their relative frequency at various stages of the ERP maintenance lifecycle. Five maintenance categories (corrective, adaptive, perfective, preventive, user support) were identified from a review of the literature on software maintenance. A new category pertaining to ‘communication, coordination and knowledge exchange with external parties’ and herein labeled ‘external parties’ is introduced to highlight the supporting role of external parties in ERP maintenance. This category includes reporting problems to vendors and consultants, tracking their progress towards …

Image Compression By Wavelet Transform., Panrong Xiao

Electronic Theses and Dissertations

Digital images are widely used in computer applications. Uncompressed digital images require considerable storage capacity and transmission bandwidth. Efficient image compression solutions are becoming more critical with the recent growth of data intensive, multimedia-based web applications.

This thesis studies image compression with wavelet transforms. As a necessary background, the basic concepts of graphical image storage and currently used compression algorithms are discussed. The mathematical properties of several types of wavelets, including Haar, Daubechies, and biorthogonal spline wavelets are covered and the Enbedded Zerotree Wavelet (EZW) coding algorithm is introduced. The last part of the thesis analyzes the compression results to …

Real-Time Distributed Scheduling In Non-Guaranteed Networks Within A Quality Of Service Framework, Hisham Nabil El-Zahhar

Archived Theses and Dissertations

No abstract provided.

On Detecting Service Violations And Bandwidth Theft In Qos Network Domains, Ahsan Habib, Sonia Fahmy, Srinivas R. Avasarala, Venkatesh Prabhakar, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

Fast Implementation Of Depth Contours Using Topological Sweep, Kim Miller, Suneeta Ramaswami, Peter Rousseeuw, Toni Sellarès, Diane Souvaine, Ileana Streinu, Anja Struyf

Computer Science: Faculty Publications

The concept of location depth was introduced in statistics as a way to extend the univariate notion of ranking to a bivariate configuration of data points. It has been used successfully for robust estimation, hypothesis testing, and graphical display. These reguire the computation of depth regions, which form a collection of nested polygons. The center of the deepest region is called the Tukey median. The only available implemented algorithms for the depth contours and the Tukey median are slow, which limits their usefulness. In this paper we describe an optimal algorithm which computes all depth contours in &Ogr;(n 2) time …

A Framework For Multilingual Information Processing, Steven Edward Atkin

Theses and Dissertations

Recent and (continuing) rapid increases in computing power now enable more of humankind's written communication to be represented as digital data. The most recent and obvious changes in multilingual information processing have been the introduction of larger character sets encompassing more writing systems. Yet the very richness of larger collections of characters has made the interpretation and processing of text more difficult. The many competing motivations (satisfying the needs of linguists, computer scientists, and typographers) for standardizing character sets threaten the purpose of information processing: accurate and facile manipulation of data. Existing character sets are constructed without a consistent strategy …

Image Magnification Using Level-Set Reconstruction, Bryan S. Morse, Duane Schwartzwald

Faculty Publications

Image magnification is a common problem in imaging applications, requiring interpolation to “read between the pixels”. Although many magnification/interpolation algorithms have been proposed in the literature, all methods must suffer to some degree the effects of impefect reconstruction―false high-frequency content introduced by the underlying original sampling. Most often, these effects manifest themselves as jagged contours in the image. This paper presents a method for constrained smoothing of such artifacts that attempts to produce smooth reconstructions of the image’s level curves while still maintaining image fidelity. This is similar to other iterative reconstruction algorithms and to Bayesian restoration techniques, but instead …

A Confidence Measure For Boundary Detection And Object Selection, William A. Barrett, Eric N. Mortensen

Faculty Publications

We introduce a confidence measure that estimates the assurance that a graph arc (or edge) corresponds to an object boundary in an image. A weighted, planar graph is imposed onto the watershed lines of a gradient magnitude image and the confidence measure is a function of the cost of fixed-length paths emanating from and extending to each end of a graph arc. The confidence measure is applied to automate the detection of object boundaries and thereby reduces (often greatly) the time and effort required for object boundary definition within a user-guided image segmentation environment.

Houghing The Hough: Peak Collection For Detection Of Corners, Junctions And Line Intersections, William A. Barrett, Kevin D. Petersen

Faculty Publications

We exploit the Accumulator Array of the Hough Transform by finding collections of (2 or more) peaks through which a given sinusoid will pass. Such sinusoids identify points in the original image where lines intersect. Peak collection (or line aggregation) is performed by making a second pass through the edge map, but instead of laying points down in the accumulator array (as with the original Hough Transform), we compute the line integral over each sinusoid that corresponds to the current edge point. If a sinusoid passes through greater than or equal to 2 peaks, we deposit that sum/integral into a …