Physical Sciences and Mathematics Commons^™

An Empirical Study Of Training And Testing Error In Boosting, David D. Latham

Dartmouth College Undergraduate Theses

Bounds have been proven for both training and testing error for the boosting algorithm AdaBoost, but in practice neither seem to produce a particularly tight bound. In this paper we share some observations of these bounds from empirical results, and then explore some properties of the algorithm with an eye towards finding an improved bound for the performance of AdaBoost. Based on our empirical evidence, the error of a hypothesis which labels examples probabilistically based upon the confidence of the vote of the weak hypotheses forms a tighter bound for the training error.

A System For Audio Personalization With Applications On Wireless Devices, David Marmaros

Dartmouth College Undergraduate Theses

We present and analyze a system for dynamically tailoring discrete audio content for numerous users based on aggregate data and intuitive feedback mechanisms. The framework for this system utilizes a flexible client-server architecture to facilitate audio dissemination, with particular attention to distribution over wireless networks. We discuss the requirements and specifications of such a system. We further analyze the algorithms and protocols required for its operation. Finally, we outline and provide data from a demonstration of this application.

Optimizing The Dimensional Method For Performing Multidimensional, Multiprocessor, Out-Of-Core Ffts, Jeremy T. Fineman

Dartmouth College Undergraduate Theses

We present an improved version of the Dimensional Method for computing multidimensional Fast Fourier Transforms (FFTs) on a multiprocessor system when the data consist of too many records to fit into memory. Data are spread across parallel disks and processed in sections. We use the Parallel Disk Model for analysis. The simple Dimensional Method performs the 1-dimensional FFTs for each dimension in term. Between each dimension, an out-of-core permutation is used to rearrange the data to contiguous locations. The improved Dimensional Method processes multiple dimensions at a time. We show that determining an optimal sequence and groupings of dimensions is …

Tcp/Ip Implementation Within The Dartmouth Scalable Simulation Framework, Michael G. Khankin

Dartmouth College Undergraduate Theses

This paper discusses TCP/IP networking, and in particular, the DaSSF implementation of TCP/IP. The paper reviews the protocols, outlines the implementation design, and demonstrates some tests. In addition, some performance and memory usage analysis is performed. We find DaSSF TCP/IP to be a viable option to the existing SSF. DaSSF TCP/IP is faster and uses less memory so we can simulate larger, more complex, models.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 9, June 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Market-Based Control Of Mobile-Agent Systems, Jonathan L. Bredin

Dartmouth College Ph.D Dissertations

Modern distributed systems scatter sensors, storage, and computation throughout the environment. Ideally these devices communicate and share resources, but there is seldom motivation for a device's owner to yield control to another user. We establish markets for computational resources to motivate principals to share resources with arbitrary users, to enforce priority in distributed systems, to provide flexible and rational limitations on the potential of an application, and to provide a lightweight structure to balance the workload over time and between devices. As proof of concept, we implement a structure software agents can use to discover and negotiate access to networked …

Effect Of Exponential Averaging On The Variability Of A Red Queue, Archan Misra, Teunis Ott, John Baras

Research Collection School Of Computing and Information Systems

The paper analyzes how using a longer memory of the past queue occupancy in computing the average queue occupancy affects the stability and variability of a RED queue. Extensive simulation studies with both persistent and Web TCP sources are used to study the variance of the RED queue as a function of the memory of the averaging process. Our results show that there is very little performance improvement (and in fact, possibly significant performance degradation) if the length of memory is increased beyond a very small value. Contrary to current practice, our results show that a longer memory reduces the …

Mobile Voice Over Ip (Mvoip): An Application-Level Protocol, Ayorkor Mills-Tettey

Dartmouth College Undergraduate Theses

Current Voice over Internet Protocol (VOIP) protocols require participating hosts to have fixed IP addresses for the duration of a VOIP call. When using a wireless-enabled host, such as a tablet computer on an 802.11 wireless network, it is possible for a participant in a VOIP call to roam around the network, moving from one subnet to another and needing to change IP addresses. This address change creates the need for mobility support in VOIP applications. We present the design of Mobile Voice over IP (MVOIP), an application-level protocol that enables such mobility in a VOIP application based on the …

Dassfnet: An Extension To Dassf For High-Performance Network Modeling, Mehmet Iyigun

Dartmouth College Undergraduate Theses

Scalable Simulation Framework (SSF) is a discrete-event simulation framework providing a unified programming interface geared towards network simulation. Dartmouth SSF (DaSSF) is a C++ implementation of SSF, designed for simulating very large-scale multi-protocol communication networks. As of the latest release, DaSSF lacks many features present in SSF and this prevents it from achieving mainstream use. To alleviate this shortcoming we designed and implemented DaSSFNet which extends DaSSF to the levels of functionality found in SSF. In this paper, we show that DaSSFNet and SSFNet are identical in operation given the same input. We also show that DaSSFNet is about twice …

A Directory Infrastructure To Support Mobile Services, Ammar Khalid

Dartmouth College Undergraduate Theses

Traditional Voice-over-IP applications such as Microsoft NetMeeting assume that the user is on a machine with a fixed IP address. If, however, the user connects to the Internet, via a wireless network, on a handheld device, his IP address frequently changes as he moves from one subnet to another. In such a situation, we need a service that can be queried for the most current IP address of a person whom we wish to contact. In this project, we design and implement such a directory service. The service authenticates all callers and callees, is robust against most host failure, and …

Measuring Early Usage Of Dartmouth's Wireless Network, Pablo Stern

Dartmouth College Undergraduate Theses

In Spring 2001, Dartmouth College installed a campus-wide 802.11b wireless network. To understand how that network is used, we examined the usage characteristics of the network over a five-week period. We monitored access points to determine user behavior, and user and network traffic characteristics. Because our study coincided with the deployment of the access points, our analysis captures the growth of a wireless network. The results of this study help understand the behavior of mobile users and provide a reference to network engineers wishing to deploy and expand similar wireless networks.

An Implementation Of Object-Oriented Program Transformation For Thought-Guided Debugging, Tiffany M. Wong

Dartmouth College Undergraduate Theses

This paper presents our design and implementation of program transformation for C++ that will be used in the context of a thought-guided debugging system. The program uses a lexical analyzer written in Flex and a grammar written in Bison that work in conjunction to scan the inputted C++ code for function definitions and class definitions. The code is then transformed to produce trace information for each defined function, while the original functionality of the code is left untouched. We also implement two additional data structures that are used for information storage during the course of the program.

Fastab: Solving The Pitch To Notation Problem, Jeremy I. Robin

Dartmouth College Undergraduate Theses

I have always been frustrated with the length of time necessary to notate a piece of music. Computers have simplified so many other aspects of our lives, it seems that they should be able to simplify this task as well. In fact, there are already two distinct ways that engineers have attempted to attack this problem. The first analyzes the waveform generated by microphone input and relies on Fourier Analysis and other similar methods. The other examines the analog signal generated by a electric guitar-like pickup placed beneath the strings. The method used by Fastab relies much less on the …

Infopipes—An Abstraction For Information Flow, Jie Huang, Andrew P. Black, Jonathan Walpole, Calton Pu

Computer Science Faculty Publications and Presentations

Building Object-Oriented Distributed Systems has been facilitated by Remote Message Sending (RMS) systems like Java RMI and implementations of CORBA. However, RMS systems are designed to support request/response interactions. Streaming applications, in contrast, are characterized by high-bandwidth, long-duration communication with stringent performance requirements. Examples of streaming applications include video-on-demand, teleconferencing, on-line education, and environmental observation. These applications transfer huge amounts of data and focus on distributed information flow rather than request/response.

To simplify the task of building distributed streaming applications, we propose a new abstraction for information flow—Infopipes. Using Infopipes, information flow becomes the heart of the system, not an …

Genetic Algorithms For Communications Network Design - An Empirical Study Of The Factors That Influence Performance, Hsinghua Chou, G. Premkumar, Chao-Hsien Chu

Research Collection School Of Computing and Information Systems

We explore the use of GAs for solving a network optimization problem, the degree-constrained minimum spanning tree problem. We also examine the impact of encoding, crossover, and mutation on the performance of the GA. A specialized repair heuristic is used to improve performance. An experimental design with 48 cells and ten data points in each cell is used to examine the impact of two encoding methods, three crossover methods, two mutation methods, and four networks of varying node sizes. Two performance measures, solution quality and computation time, are used to evaluate the performance. The results obtained indicate that encoding has …

Globally Convergent Approximate Dynamic Programming Applied To An Autolander, J.J. Murray, Richard Saeks, C.J. Cox, George G. Lendaris

Systems Science Faculty Publications and Presentations

A globally convergent nonlinear Approximate Dynamic Programming algorithm is described, and an implementation of the algorithm in the linear case is developed. The resultant linear Approximate Dynamic Programming algorithm is illustrated via the design of an autolander for the NASA X-43 research aircraft, without a priori knowledge of the X-43's flight dynamics.

Verifying Properties Of Neural Networks, Pedro Rodriques, J. Félix Costa, Hava Siegelmann

Hava Siegelmann

In the beginning of nineties, Hava Siegelmann proposed a new computational model, the Artificial Recurrent Neural Network (ARNN), and proved that it could perform hypercomputation. She also established the equivalence between the ARNN and other analog systems that support hypercomputation, launching the foundations of an alternative computational theory. In this paper we contribute to this alternative theory by exploring the use of formal methods in the verification of temporal properties of ARNNs. Based on the work of Bradfield in verification of temporal properties of infinite systems, we simplify his tableau system, keeping its expressive power, and show that it is …

E-Docspros : Exploring Texpros Into E-Business Era, Zhenfu Cheng

Dissertations

Document processing is a critical element of office automation. TEXPROS (TEXt PROcessing System) is a knowledge-based system designed to manage personal documents. However, as the Internet and e-Business changed the way offices operate, there is a need to re-envision document processing, storage, retrieval, and sharing. In the current environment, people must be able to access documents remotely and to share those documents with others. e-DOCPROS (e-DOCument PROcessing System) is a new document processing system that takes advantage of many of TEXPROS's structures but adapts the system to this new environment. The new system is built to serve e-businesses, takes advantage …

Waqs : A Web-Based Approximate Query System, George Jyh-Shian Chang

Dissertations

The Web is often viewed as a gigantic database holding vast stores of information and provides ubiquitous accessibility to end-users. Since its inception, the Internet has experienced explosive growth both in the number of users and the amount of content available on it. However, searching for information on the Web has become increasingly difficult. Although query languages have long been part of database management systems, the standard query language being the Structural Query Language is not suitable for the Web content retrieval.

In this dissertation, a new technique for document retrieval on the Web is presented. This technique is designed …

Augmenting Applications With Hyper Media, Functionality And Meta-Information, Roberto Galnares

Dissertations

The Dynamic Hypermedia Engine (DHE) enhances analytical applications by adding relationships, semantics and other metadata to the application's output and user interface. DHE also provides additional hypermedia navigational, structural and annotation functionality. These features allow application developers and users to add guided tours, personal links and sharable annotations, among other features, into applications. DHE runs as a middleware between the application user interface and its business logic and processes, in a n-tier architecture, supporting the extra functionalities without altering the original systems by means of application wrappers.

DHE automatically generates links at run-time for each of those elements having relationships …

Knowledge-Based Document Retrieval With Application To Texpros, Fang Sheng

Dissertations

Document retrieval in an information system is most often accomplished through keyword search. The common technique behind keyword search is indexing. The major drawback of such a search technique is its lack of effectiveness and accuracy. It is very common in a typical keyword search over the Internet to identify hundreds or even thousands of records as the potentially desired records. However, often few of them are relevant to users' interests.

This dissertation presents knowledge-based document retrieval architecture with application to TEXPROS. The architecture is based on a dual document model that consists of a document type hierarchy and, a …

Supporting Adaptive Ubiquitous Applications With The Solar System, Guanling Chen, David Kotz

Computer Science Technical Reports

As we embed more computers into our daily environment, ubiquitous computing promises to make them less noticeable and help to prevent information overload. We see, however, few ubiquitous applications that are able to adapt to the dynamics of user, physical, and computational context. We believe that there are two challenges causing this lack of ubiquitous applications: there is no flexible and scalable way to support information collection and dissemination in a ubiquitous and mobile environment, and there is no general approach to building adaptive applications given heterogeneous contextual information. We propose a system infrastructure, Solar, to meet these challenges. Solar …

Introduction (2001), Association Of Christians In The Mathematical Sciences

ACMS Conference Proceedings 2001

Thirteenth ACMS Conference on Mathematics from a Christian Perspective

Decision Making Based On Quantitative And Qualitative Evaluations, Rohan A. Pandit

Theses

This study emphasizes mainly on the influence of evaluations, both qualitative and quantitative, on decision making for many occasions that occur in business and technically oriented settings. Decisions made with a certain fuzzy as wen as technical behavior are structured by means of computer-assisted decision-making tools. Decision support tools assist decision makers in making crucial decisions. For instance the tool that has been designed for the purpose of this research will be used for selecting capital-intensive products. It is also intended to prove that with the help of decision support systems decision makers could make decisions by reducing fuzzy decision …

Data Mining Using Neural Networks For Large Credit Card Record Sites, Wei Wei

Theses

Data mining using neural networks has been applied in various financial fields such as risk mitigation, missing data filling, fraud detection, and customer profile classification etc. This master thesis work aims to develop methodologies to mine large sets of records and in particular to fill missing data in these records. The steps include data cleansing, data selection, data preprocessing, data representation, data clustering and finally the missing data filling. Furthermore, this work designs algorithms to evaluate the supervised neural networks' performance, which is helpful for the future research on data prediction and classification. A case study based on a large …

Schedule (2001), Association Of Christians In The Mathematical Sciences

ACMS Conference Proceedings 2001

Thirteenth ACMS Conference on Mathematics from a Christian Perspective

Table Of Contents (2001), Association Of Christians In The Mathematical Sciences

ACMS Conference Proceedings 2001

Thirteenth ACMS Conference on Mathematics from a Christian Perspective

Improving A Brokering System For Linking Distributed Simulations, Thomas B. Stephens

Dartmouth College Undergraduate Theses

The Agent Based Environment for Linking Simulations (ABELS) is a software framework designed to provide disparate simulations with dynamically updated data sources. It allows simulations and other agents to join a "cloud" of interacting producers and consumers of data. Once they have joined the cloud, they can publish services to other members and use methods published by others. This paper presents the initial design of a set of matchmaking components for the ABELS framework. These components dictate how services describe their abilities and requirements to ABELS. Furthermore, they help ABELS successfully match data producing services to the requests of data …

Oral History Interview With Dick Hedger, Philip L. Frana

Philip L Frana

Richard Hedger begins the interview describing his education in electrical engineering at the University of Minnesota. Following graduation he accepted a position at IBM Rochester in the optical character recognition group. He then discusses his shift to software development. Eventually he joined the Service and Support group developing application software supporting facilities infrastructures for the IBM System/3, and System/360. In various places in the interview, he describes some of the programming techniques in ...

Babylon 5 Collectable Game Network Interface, Jeremy Tillman

Honors Capstone Projects and Theses

No abstract provided.