Physical Sciences and Mathematics Commons^™

The Panda Array I/O Library On The Galley Parallel File System, Joel T. Thomas

Dartmouth College Undergraduate Theses

The Panda Array I/O library, created at the University of Illinois, Urbana-Champaign, was built especially to address the needs of high-performance scientific applications. I/O has been one of the most frustrating bottlenecks to high performance for quite some time, and the Panda project is an attempt to ameliorate this problem while still providing the user with a simple, high-level interface. The Galley File System, with its hierarchical structure of files and strided requests, is another attempt at addressing the performance problem. My project was to redesign the Panda Array library for use on the Galley file system. This project involved …

Object Oriented Scenes For Virtual Light, Jonathan A. Moore

Dartmouth College Undergraduate Theses

Ray tracing is one of many way to use a computer to generate an image. Ray tracers produce images by simulating light. Eliminating the details that might distract one from the interesting parts of ray tracing algorithms was purpose of my thesis project. The software I have written can be divide into three parts: the virtual frame buffer, the support classes and the ray tracing abstract base classes. The virtual frame buffer class, vfb, provides a simple means of rendering and studying the final image produced by a graphical algorithm. The support classes provide an elegant notation for the equations …

Implementation And Analysis Of Software Based Fault Isolation, Scott M. Silver

Dartmouth College Undergraduate Theses

Extensible applications rely upon user-supplied, untrusted modules to extend their functionality. To remain reliable, applications must isolate themselves from user modules. One method places each user module in a separate address space (process), which uses hardware virtual memory support to isolate the user process. Costly inter-process communication, however, prohibits frequent communication between the application and the untrusted module. We implemented and analyzed a software method for isolating an application from user modules. The technique uses a single address space. We provide a logical address space and per-module access to system resources for each module. Our software technique is a two-step …

Segmenting Workstation Screen Images, Denis M. Serenyi

Dartmouth College Undergraduate Theses

No abstract provided.

A Multiple Discrete Pass Algorithm On A Dec Alpha 2100, Scott R. Cushman

Dartmouth College Undergraduate Theses

No abstract provided.

Simulation Of A Video-On-Demand System, Song Bac Toh

Dartmouth College Undergraduate Theses

This paper presents a simulation study of a video-on-demand system. The focus of the study is the effectiveness of different caching strategies on a video-on-demand system with two levels of cache, RAM and disks, in front of a tape library. Using an event-driven simulator, I show that caching was helpful in increasing the service capacity of the system. On-demand caching showed its advantages especially when the requests were clustered around a few popular titles (in other words, there was temporal locality).

Tias: A Transportable Intelligent Agent System, Kenneth Harker

Dartmouth College Undergraduate Theses

In recent years, there has been an explosive growth in the amount of information available to our society. In particular, the amount of information available on-line through vast networks like the global Internet has been growing at a staggering rate. This growth rate has by far exceeded the rate of growth in network speeds, as has the number of individuals and organizations seeking access to this information. There is thus a motivation to find abstract methods of manipulating this on-line data in ways that both serve the needs of end users efficiently and use network resources intelligently. In lieu of …

Efficient Parallel Algorithms For Closest Point Problems, Peter Su

Dartmouth College Ph.D Dissertations

This dissertation develops and studies fast algorithms for solving closest point problems. Algorithms for such problems have applications in many areas including statistical classification, crystallography, data compression, and finite element analysis. In addition to a comprehensive empirical study of known sequential methods, I introduce new parallel algorithms for these problems that are both efficient and practical. I present a simple and flexible programming model for designing and analyzing parallel algorithms. Also, I describe fast parallel algorithms for nearest-neighbor searching and constructing Voronoi diagrams. Finally, I demonstrate that my algorithms actually obtain good performance on a wide variety of machine architectures. …

Bmmc Permutations On A Decmpp 12000/Sx 2000, Kristin Bruhl

Dartmouth College Undergraduate Theses

Increasingly, modern computing problems, including many scientific and business applications, require huge amounts of data to be examined, modified, and stored. Parallel computers can be used to decrease the time needed to operate on such large data sets, by allowing computations to be performed on many pieces of data at once. For example, on the DECmpp machine used in our research, there are 2048 processors in the parallel processor array. The DECmpp can read data into each of these processors, perform a computation in parallel on all of it, and write the data out again, theoretically decreasing the execution time …

Human Creativity Through Computer Gaming, Christine Mcgavran

Dartmouth College Undergraduate Theses

No abstract provided.

Accurate Verification Of Five-Axis Numerically Controlled Machining, Jerome L. Quinn

Dartmouth College Ph.D Dissertations

Current automated machining systems are composed of a number of components to aid in bringing a surface from design to physical completion. Numerically controlled (NC) milling machines are used to cut parts out of stock. Programming these machines to cut a desired surface is still largely a matter of experienced human participation. Therefore, the need exists to verify that tool programs produce the desired part.

We present recent developments in the verification of NC tool programs. Many of these methods rely on approximating the stock material as vectors whose lengths reflect the amount of uncut material at any point. This …

Formal Implementation Of High-Level Languages For Data-Parallel Programming, Deb Banerjee

Dartmouth College Ph.D Dissertations

The success of parallel architectures has been limited by the lack of high-level parallel programming languages and useful programming models. The data-parallel model of programming has been demonstrated to be useful and natural on a wide variet of parallel architectures. This dissertation presents a set of formal techniques for compiling high- level languages based on data-parallelism.

Spede: A Simple Programming Environment For Distributed Execution (Users' Manual), James Gochee

Dartmouth College Undergraduate Theses

Traditional single processor computers are quickly reaching their full computational potentials. The quest for faster and faster chips have brought technology to the point where the laws of physics are hampering future gains. Significant gains in speed must therefore come from using multiple processors instead of a single processor. This technology usually represents itself in the form of a parallel computer, such as the Connection Machine Model 5. Recently however, much interest has been focused on software that organizes single processor computers to behave like a parallel computer. This is desirable for sites which have large installations of workstations, since …

Spede: Simple Programming Environment For Distributed Execution, James Gochee

Dartmouth College Undergraduate Theses

One of the main goals for people who use computer systems, particularly computational scientists, is speed. In the quest for ways to make applications run faster, engineers have developed parallel computers, which use more than one CPU to solve a task. However, many institutions already posses significant computational power in networks of workstations. Through software, it is possible to glue together clusters of machines to simulate a parallel environment. SPEDE is one such system, designed to place the potential of local machines at the fingertips of the programmer. Through a simple interface, users design computational objects that can be linked …

Making Mail Friendlier: Adding Macintosh Features And Multimedia Documents In Unix Mail, John R. Meier

Dartmouth College Undergraduate Theses

This paper describes a Macintosh application which acts as a front-end to Unix mail. Features of the Macintosh interface such as icons, menus, and windows replace the command driven interface. Complicated editing commands are replaced with mouse selection and cut, copy, and paste. Message can be composed of text, pictures, and any Macintosh file, because they are encoded into plain text, sent through the mail system,and then unencoded by the receiving end. The designs of the mail server and communications interface are such that mail servers and communications other than Unix mail and a serial line may be easily implemented.

Creating Havoc: Havoc Development Program, David Cohn, Stephen Madancy

Dartmouth College Undergraduate Theses

One area where use of the computer is essential is in the modern scientific laboratory. High speed computation, data storage and data analysis enable scientists to perform experiments that would otherwise be impractical. A problem inherent to the effective use of special purpose laboratory computers, however, is the fact that this equipment has generally been developed for highly specific uses, and has either tried to cope with existing high-level languages or has abandoned the attempt and required the user to program in a low-level assembly or machine language. Our idea was to design, develop and implement a programming language that …