Computer Sciences Commons^™

Randomized Motion Planning For Groups Of Nonholonomic Robots, Christopher M. Clark, Stephen M. Rock.

Computer Science and Software Engineering

This paper presents a technique for motion planning which is capable of planning trajectories for a large number of nonholonomic robots. The robots plan within a two dimensional environment that consists of stationary/moving obstacles, and fixed boundaries. Each robot uses randomized motion planner techniques based on Probabilistic Road Maps (PRM’s) to construct it’s own trajectory that is free of collisions with moving obstacles and other robots. The randomized motion planner allows easy integration of the robots nonholonomic constraint into the planning so that only kinematically consistent plans are constructed. It is important to include this constraint in the planning problem …

Topological Noise Removal, Igor Guskov, Zoë J. Wood

Computer Science and Software Engineering

Meshes obtained from laser scanner data often contain topological noise due to inaccuracies in the scanning and merging process. This topological noise complicates subsequent operations such as remeshing, parameterization and smoothing. We introduce an approach that removes unnecessary nontrivial topology from meshes. Using a local wave front traversal, we discover the local topolo-gies of the mesh and identify features such as small tunnels. We then identify non-separating cuts along which we cut and seal the mesh, reducing the genus and thus the topological complexity of the mesh.

Perspective Filters As A Means For Interoperability Among Information-Centric Decision-Support Systems, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

No abstract provided.

Information-Centric Decision-Support Systems: A Blueprint For ‘Interoperability’, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

For the past 20 years the US military services have suffered under the limitations of stove-piped computer software applications that function as discrete entities within a fragmented data-processing environment. Lack of interoperability has been identified by numerous think tanks, advisory boards, and studies, as the primary information systems problem (e.g., Army Science Board 2000, Air Force SAB 2000 Command and Control Study, and NSB Network-Centric Naval Forces 2000). Yet, despite this level of attention, all attempts to achieve interoperability within the current data-centric information systems environment have proven to be expensive, unreliable, and generally unsuccessful.

Proceedings Of The 2001 Onr Decision-Support Workshop Series: Continuing The Revolution In Military Affairs, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

In August of 1998 the Collaborative Agent Design Research Center (CADRC) of the California Polytechnic State University in San Luis Obispo (Cal Poly), approached the Office of Naval Research (ONR) with the proposal for an annual workshop focusing on emerging concepts in decision-support systems for military applications. The proposal was considered timely by the ONR Logistics Program Office for at least two reasons. First, rapid advances in information systems technology over the past decade had produced distributed, collaborative computer-assistance capabilities with profound potential for providing meaningful support to military decision makers. Indeed, some systems based on these new capabilities such …

Approximation Techniques For Average Completion Time Scheduling, Chandra Chekuri, Rajeev Motwani, Balas Natarajan, Clifford Stein

Dartmouth Scholarship

We consider the problem of nonpreemptive scheduling to minimize average ( weighted) completion time, allowing for release dates, parallel machines, and precedence constraints. Recent work has led to constant-factor approximations for this problem based on solving a preemptive or linear programming relaxation and then using the solution to get an ordering on the jobs. We introduce several new techniques which generalize this basic paradigm. We use these ideas to obtain

improved approximation algorithms for one-machine scheduling to minimize average completion time with release dates. In the process, we obtain an optimal randomized on-line algorithm for the same problem that beats …

Webalps Implementation And Performance Analysis: Using Trusted Co-Servers To Enhance Privacy And Security Of Web Interactions, Shan Jiang

Dartmouth College Master’s Theses

The client-server model of the Web poses a fundamental trust issue: clients are forced to trust in secrecy and correctness of computation occurring at a remote server of unknown credibility. The current solution for this problem is to use a PKI (Public Key Infrastructure) system and SSL (Secure Sockets Layer) digital certificates to prove the claimed identity of a server and establish an authenticated, encrypted channel between the client and this server. However, this approach does not address the security risks posed by potential malicious server operators or any third parties who may penetrate the server sites. The WebALPS (Web …

Immaccs: A Multi-Agent Decision-Support System, Jens G. Pohl, Mark Porczak, Kym Jason Pohl, Russell Leighton, Hisham Assal, Alan Davis, Lakshmi Vempati, Anthony Wood

Collaborative Agent Design (CAD) Research Center

This report describes work performed by the Collaborative Agent Design Research Center for the US Marine Corps Warfighting Laboratory (MCWL), on the IMMACCS experimental decision-support system. IMMACCS (Integrated Marine Multi-Agent Command and Control System) 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, IMMACCS includes an ontological model of the battlespace that represents the behavioral characteristics and relationships among real world entities such as friendly and enemy assets, infrastructure objects …

What Mathematical Paradoxes Teach Us About Paradoxes In Christianity, Paul Bialek

ACMS Conference Proceedings 2001

In Christian academic circles, we talk about the integration of our faith and learning. That is, we seek to discover and develop connections between our Christian faith and our particular discipline. This is notoriously difficult when the discipline is mathematics. I have found that asking myself these three questions has helped me to integrate my Christian faith with mathematics, although they could be applied to any discipline: (1) How does the fact that I am a Christian affect the way I view mathematics? (2) How does the fact that I am a mathematician affect the way I view Christianity? (3) …

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 …

Smartreminder: A Case Study On Context-Sensitive Applications, Arun Mathias

Dartmouth College Undergraduate Theses

Designing context-sensitive applications is challenging. We design and implement SmartReminder to explore designing context-sensitive applications and to demonstrate how the SOLAR system can be used in developing such applications. SmartReminder is an application that reminds the user based on contextual information. Current appointment-reminder applications remind the user about their appointments at an arbitrarily specified time. For instance, they might remind the user ten minutes before each appointment. SmartReminder, on the other hand, uses contextual information, like location, to better estimate the appropriate reminder time for each appointment. It reminds the user based on where they are, where they need to …

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.

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.

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 …

Implementing A Database Information System For An Electronic Baseball Scorecard, Tiffany M. Wong

Dartmouth College Undergraduate Theses

We present our design and implementation of a database system of information storage and retrieval for an electronic baseball scorecard. The program uses the relational MySQL database to hold information and a Tcl API to handle interactions between the database and the user interface code. This paper discusses the inner workings of how information storage was broken down inside the database, how queries were internally constructed in accordance with the user's input, and how statistics for players and teams were calculated and returned to the user. Finally, we discuss some limitations attached to our current implementation of the program and …

An Armored Data Vault, Alex Iliev

Dartmouth College Undergraduate Theses

We consider the problem of secure long-term archiving of network traffic, an instance of the problem of storing data securely. We approach the problem using secure hardware, which enables the enforcement of flexible access policy. The policy cannot be circumvented by anyone, even insiders, and so we are assured that access to the data is as originally intended. The policy can be expressed as any feasible computation, as it will be checked inside the secure hardware without possibility of interference. We discuss our design of a device to perform such network data archiving and have implemented a prototpe device. We …

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 …

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.

Efficient Compression Of Generic Function Dispatch Tables, Eric Kidd

Dartmouth College Undergraduate Theses

A generic function is similar to an overloaded operator, but provides a way to select an appropriate behavior at run-time instead of compile-time. Dujardin and colleagues have proposed an algorithm for building and compressing generic function dispatch tables. We present several modifications to their algorithm, including an improvement to Pseudo-Closest-Poles and two new algorithms for compressing pole tables. The two new compression algorithms are simple and fast, and one produces smaller output than the original.

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 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.

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 …

Ecomrisk.Org : A Site To Classify And Organize The Risks Of Performing Business On The Internet, Aidan Stanley Marcuss

Dartmouth College Undergraduate Theses

As the use of the Internet and other computer networks to transact business grows, there is an ever increasing need for those taking part in those transactions to understand the risks of doing so. While there are many web sites that have created valuable databases of specific vulnerabilities for certain types of hardware and software, there is a lack of focus on attempting to analyze the interaction of businesses, their systems, computer networks, and their customers and the risks that are created by either intended or unattended interactions. EcomRISK.org is a web site that presents a clear taxonomy to classify …

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.

Summarizing Data Sets For Classification, Christopher W. Kinzig, Krishnaprasad Thirunarayan, Gary B. Lamont, Robert E. Marmelstein

Kno.e.sis Publications

This paper describes our approach and experiences with implementing a data mining system using genetic algorithms in C++. In contrast with earlier classification algorithms that tended to “tile” the data sets using some pre-specified “shapes”, the proposed system is based on Marmelstein’s work on determining natural boundaries for class homogeneous regions. These boundaries are further refined to construct a compact set of simple data mining rules for classification.

Computer Science: A Guide To Selected Resources On The Internet., Michael Knee

University Libraries Faculty Scholarship

No abstract provided.

Query Processing With An Fpga Coprocessor Board, Jack S. Jean, Guozhu Dong, Hwa Zhang, Xinzhong Guo, Baifeng Zhang

Kno.e.sis Publications

In this paper, a commercial FPGA coprocessor board is used to accelerate the processing of queries on a relational database that contains texts and images. FPGA designs for text searching and image matching are described and their performances summarized. A potential design for a database JOIN operator is then studied. A query optimization preprocessor is then proposed.

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.

Three Problems From Number Theory, Robert Brabenec

ACMS Conference Proceedings 2001

This paper discusses the experiences of Wheaton College mathematics and computer science department colloquium as they explored open-ended problems.

The Soviet Concept Of The Correlation Of Forces, James Bradley

ACMS Conference Proceedings 2001

This paper takes a look at the Soviet Union’s accumulation of nuclear weapons during the Cold War and what mathematical strategy they employed to make their choices.