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Full-Text Articles in Physical Sciences and Mathematics
Existence Theorems For Scheduling To Meet Two Objectives, April M. Rasala
Existence Theorems For Scheduling To Meet Two Objectives, April M. Rasala
Dartmouth College Undergraduate Theses
We will look at the existence of schedules which are simultaneously near-optimal for two criteria. First, we will present some techniques for proving existence theorems, in a very general setting, for bicriterion scheduling problems. We will then use these techniques to prove existence theorems for a large class of problems. We will consider the relationship between objective functions based on completion time, flow time, lateness and the number of on-time jobs. We will also present negative results first for the problem of simultaneously minimizing the maximum flow time and average weighted flow time and second for minimizing the maximum flow …
A Two Dimensional Crystalline Atomic Unit Modular Self-Reconfigurable Robot, Marsette Arthur Vona Iii
A Two Dimensional Crystalline Atomic Unit Modular Self-Reconfigurable Robot, Marsette Arthur Vona Iii
Dartmouth College Undergraduate Theses
Self-reconfigurable robots are designed so that they can change their external shape without human intervention. One general way to achieve such functionality is to build a robot composed of multiple, identical unit modules. If the modules are designed so that they can be assembled into rigid structures, and so that individual units within such structures can be relocated within and about the structure, then self-reconfiguration is possible. We propose the Crystalline Atomic unit modular self-reconfigurable robot, where each unit is called an Atom. In two dimensions, an Atom is square. Connectors at the faces of each Atom support structure formation …
An Application Of Word Sense Disambiguation To Information Retrieval, Jason M. Whaley
An Application Of Word Sense Disambiguation To Information Retrieval, Jason M. Whaley
Dartmouth College Undergraduate Theses
The problems of word sense disambiguation and document indexing for information retrieval have been extensively studied. It has been observed that indexing using disambiguated meanings, rather than word stems, should improve information retrieval results. We present a new corpus-based algorithm for performing word sense disambiguation. The algorithm does not need to train on many senses of each word; it uses instead the probability that certain concepts will occur together. That algorithm is then used to index several corpa of documents. Our indexing algorithm does not generally outperform the traditional stem-based tf.idf model.
Computers, Art And Smart Rooms: A Smart Picture Frame That Senses The Weather And Genetically Evolves Images, Marisa E. Kolodny
Computers, Art And Smart Rooms: A Smart Picture Frame That Senses The Weather And Genetically Evolves Images, Marisa E. Kolodny
Dartmouth College Undergraduate Theses
By using sensors to sense the environment and genetic programming to evolve images, this thesis explores two methods for developing smart pictures that can be integrated with a living space. The system presented senses the weather and indoor conditions, displays current weather and forecast information retrieved from the web, and displays genetically evolved images. Sensing the weather not only provides the user with information they might find useful, but also allows the computer to gain a better understanding of the user which in turn allows the computer to respond more accurately. Genetic programming allows the computer to better respond to …
The Implementation Of Dassf Otcl Apis, Hongxia Quan
The Implementation Of Dassf Otcl Apis, Hongxia Quan
Dartmouth College Undergraduate Theses
As an extension of Tcl, Otcl provides basic functionality for object-oriented programming in scripting language Tcl. We implemented the Otcl APIs for DaSSF (a parallel simulator software written in C++ at Dartmouth College) using Tclcl software package written in University of California at Berkeley. This document discussed the issues involved in the implementation, especially the communications between C++ objects and Otcl objects required by DaSSF and the naming problems.
Improved Computer Detection And Mapping Of Cerebral Oxygenation, David H. Kung
Improved Computer Detection And Mapping Of Cerebral Oxygenation, David H. Kung
Dartmouth College Undergraduate Theses
Near-infrared (NIR) optical image reconstruction that incorporates blood oxygen level dependant (BOLD) magnetic resonance imaging has the potential to improve both quantifiable measurement of oxygenation and the spatial resolution involved in such mapping. My thesis continues some preliminary work in this area through development of an analytic diffusion parameter estimation algorithm for use with a NIR imaging array and development of a finite element mesh utility to read a priori BOLD images and tag them with property elements for NIR image resolution improvement.
Two Algorithms For Performing Multidimensional, Multiprocessor, Out-Of-Core Ffts, Lauren M. Baptist
Two Algorithms For Performing Multidimensional, Multiprocessor, Out-Of-Core Ffts, Lauren M. Baptist
Dartmouth College Undergraduate Theses
We show two algorithms for computing multidimensional Fast Fourier Transforms (FFTs) on a multiprocessor system with distributed memory when problem sizes are so large that the data do not fit in the memory of the entire system. Instead, data reside on a parallel disk system and are brought into memory in sections. We use the Parallel Disk Model for implementation and analysis. The first method is a straightforward out-of-core variant of a well-known method for in-core, multidimensional FFTs. It performs 1-dimensional FFT computations on each dimension in turn. This method is easy to generalize to any number of dimensions, and …
Fast Out-Of-Core Sorting On Parallel Disk Systems, Matthew D. Pearson
Fast Out-Of-Core Sorting On Parallel Disk Systems, Matthew D. Pearson
Dartmouth College Undergraduate Theses
This paper discusses our implementation of Rajasekaran's (l,m)-mergesort algorithm (LMM) for sorting on parallel disks. LMM is asymptotically optimal for large problems and has the additional advantage of a low constant in its I/O complexity. Our implementation is written in C using the ViC* I/O API for parallel disk systems. We compare the performance of LMM to that of the C library function qsort on a DEC Alpha server. qsort makes a good benchmark because it is fast and performs comparatively well under demand paging. Since qsort fails when the swap disk fills up, we can only compare these algorithms …
Investigating Measures For Pairwise Document Similarity, Jeffrey D. Isaacs
Investigating Measures For Pairwise Document Similarity, Jeffrey D. Isaacs
Dartmouth College Undergraduate Theses
The need for a more effective similarity measure is growing as a result of the astonishing amount of information being placed online. Most existing similarity measures are defined by empirically derived formulas and cannot easily be extended to new applications. We present a pairwise document similarity measure based on Information Theory, and present corpus dependent and independent applications of this measure. When ranked with existing similarity measures over TREC FBIS data, our corpus dependent information theoretic similarity measure ranked first.
Parallel Dassf Discrete-Event Simulation Without Shared Memory, James D. Chalfant
Parallel Dassf Discrete-Event Simulation Without Shared Memory, James D. Chalfant
Dartmouth College Undergraduate Theses
The Dartmouth implementation of the Scalable Simulation Framework (DaSSF) is a discrete-event simulator used primarily in the simulation of networks. It achieves high performance through parallel processing. DaSSF 1.22 requires shared memory between all processors in order to operate. This limits the number of processors available and the hardware platforms that can exploit parallelism. We are interested in extending parallel DaSSF operation to architectures without shared memory. We explore the requirements of this by implementing parallel DaSSF using MPI as the sole form of interaction between processors. The approaches used to achieve this can be abstracted and applied to the …