Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 17 of 17

Full-Text Articles in Physical Sciences and Mathematics

Target-Dominant Chinese-English Machine Translation, Dan Su Nov 2004

Target-Dominant Chinese-English Machine Translation, Dan Su

Theses and Dissertations

Information exchange is increasing rapidly with the advent of globalization. As the language spoken by the most people in today's world, Chinese will play an important role in information exchange in the future. Therefore, we need an efficient and practical means to access the increasingly large volume of Chinese data. This thesis describes a target-dominant Chinese-English machine translation system, which can translate a given Chinese news sentence into English. We conjecture that we can improve the state of the art of MT using a TDMT approach. This system has participated in the NIST (National Institute of Standards and Technology) 2004 …


Automating The Extraction Of Domain-Specific Information From The Web-A Case Study For The Genealogical Domain, Troy L. Walker Nov 2004

Automating The Extraction Of Domain-Specific Information From The Web-A Case Study For The Genealogical Domain, Troy L. Walker

Theses and Dissertations

Current ways of finding genealogical information within the millions of pages on the Web are inadequate. In an effort to help genealogical researchers find desired information more quickly, we have developed GeneTIQS, a Genealogy Target-based Information Query System. GeneTIQS builds on ontology-based methods of data extraction to allow database-style queries on the Web. This thesis makes two main contributions to GeneTIQS. (1) It builds a framework to do generic ontology-based data extraction. (2) It develops a hybrid record separator based on Vector Space Modeling that uses both formatting clues and data clues to split pages into component records. The record …


Does The Halting Necessary For Hardware Trace Collection Inordinately Perturb The Results?, Myles G. Watson Nov 2004

Does The Halting Necessary For Hardware Trace Collection Inordinately Perturb The Results?, Myles G. Watson

Theses and Dissertations

Processor address traces are invaluable for characterizing workloads and testing proposed memory hierarchies. Long traces are needed to exercise modern cache designs and produce meaningful results, but are difficult to collect with hardware monitors because microprocessors access memory too frequently for disks or other large storage to keep up. The small, fast buffers of the monitors fill quickly; in order to obtain long contiguous traces, the processor must be stopped while the buffer is emptied. This halting may perturb the traces collected, but this cannot be measured directly, since long uninterrupted traces cannot be collected. We make the case that …


Real-Time Image Enhancement Using Texture Synthesis, Matthew J. Sorensen Nov 2004

Real-Time Image Enhancement Using Texture Synthesis, Matthew J. Sorensen

Theses and Dissertations

This thesis presents an approach to real-time image enhancement using texture synthesis. Traditional image enhancement techniques are typically time consuming, lack realistic detail, or do not scale well for large magnification factors.

Real-time Enhancement using Texture Synthesis (RETS) combines interpolation, classification, and patch-based texture synthesis to enhance low-resolution imagery, particularly aerial imagery. RETS uses as input a low-resolution source image and several high-resolution sample textures. The output of RETS is a high-resolution image with the structure of the source image, but with detail consistent with the high-resolution sample textures. We show that RETS can enhance large amounts of imagery in …


Improved Signal Integrity In Ieee 1149.1 Boundary Scan Designs, Efren De Jesus Rangel Taboada Nov 2004

Improved Signal Integrity In Ieee 1149.1 Boundary Scan Designs, Efren De Jesus Rangel Taboada

Theses and Dissertations

This work is an analysis of solutions to problems derived from inherent timing and signal integrity issues in the use and application of the IEEE 1149.1 Standard at the board level in conjunction with its test system. Setup or hold times violations may occur in a boundary scan chain using IEEE 1149.1 compliant devices. A practical study of the TDI-TDO scan data path has been conducted to show where problems may arise in relationship to a particular board topology and test system. This work points to differences between passing and failing scan path tests for problem characterization. Serial data flow …


Disk Based Model Checking, Tonglaga Bao Oct 2004

Disk Based Model Checking, Tonglaga Bao

Theses and Dissertations

Disk based model checking does not receive much attention in the model checking field becasue of its costly time overhead. In this thesis, we present a new disk based algorithm that can get close to or faster verification speed than a RAM based algorithm that has enough memory to complete its verification. This algorithm also outperforms Stern and Dill's original disk based algorithm. The algorithm partitions the state space to several files, and swaps files into and out of memory during verification. Compared with the RAM only algorithm, the new algoritm reduces hash table insertion time by reducing the cost …


Vision-Based Human Directed Robot Guidance, Richard B. Arthur Oct 2004

Vision-Based Human Directed Robot Guidance, Richard B. Arthur

Theses and Dissertations

This paper describes methods to track a user-defined point in the vision of a robot as it drives forward. This tracking allows a robot to keep itself directed at that point while driving so that it can get to that user-defined point. I develop and present two new multi-scale algorithms for tracking arbitrary points between two frames of video, as well as through a video sequence. The multi-scale algorithms do not use the traditional pyramid image, but instead use a data structure called an integral image (also known as a summed area table). The first algorithm uses edge-detection to track …


Network-Layer Selective Security, Casey T. Deccio Sep 2004

Network-Layer Selective Security, Casey T. Deccio

Theses and Dissertations

The Internet and other large computer networks have become an integral part of numerous daily processes. Security at the network layer is necessary to maintain infrastructure survivability in the case of cyber attacks aimed at routing protocols. In order to minimize undesired overhead associated with added security at this level, the notion of selective security is proposed. This thesis identifies elements in network topologies that are most important to the survivability of the network. The results show that the strategic placement of network security at critical elements will improve overall network survivability without the necessity of universal deployment.


An Ecological Display For Robot Teleoperation, Robert W. Ricks Aug 2004

An Ecological Display For Robot Teleoperation, Robert W. Ricks

Theses and Dissertations

This thesis presents an interface for effectively teleoperating robots that combines an ecological display of range and video information with quickening based on dead-reckoning prediction. This display is built by viewing range and video information from a virtual camera trailing the robot. This is rendered in 3-D by using standard hardware acceleration and 3-D graphics software. Our studies demonstrate that this interface improves performance for most people, including those that do not have much previous experience with robotics. These studies involved 32 test subjects in a simulated environment and 8 in the real world. Subjects were required to drive the …


A Qualitative Method For Dynamic Transport Selection In Heterogeneous Wireless Environments, Heidi R. Duffin Aug 2004

A Qualitative Method For Dynamic Transport Selection In Heterogeneous Wireless Environments, Heidi R. Duffin

Theses and Dissertations

Computing devices are commonly equipped with multiple transport technologies such as IrDA, Bluetooth and WiFi. Transport switching technologies, such as Quality of Transport (QoT), take advantage of this heterogeneity to keep network sessions active as users move in and out of range of various transports or as the networking environment changes. During an active session, the goal is to keep the device connected over the best transport currently available. To accomplish that, this thesis introduces a two-phase decision making protocol. In phase one, intra-device prioritization, users indicate the relative importance of criteria such as speed, power, service charge, or signal …


Preserving Trust Across Multiple Sessions In Open Systems, Fuk-Wing Thomas Chan Jul 2004

Preserving Trust Across Multiple Sessions In Open Systems, Fuk-Wing Thomas Chan

Theses and Dissertations

Trust negotiation, a new authentication paradigm, enables strangers on the Internet to establish trust through the gradual disclosure of digital credentials and access control policies. Previous research in trust negotiation does not address issues in preserving trust across multiple sessions. This thesis discusses issues in preserving trust between parties who were previously considered strangers. It also describes the design and implementation of trust preservation in TrustBuilder, a prototype trust negotiation system. Preserving trust information can reduce the frequency and cost of renegotiation. A scenario is presented that demonstrates that a server supporting trust preservation can recoup the cost of the …


Grouping Search-Engine Returned Citations For Person-Name Queries, Reema Al-Kamha Jul 2004

Grouping Search-Engine Returned Citations For Person-Name Queries, Reema Al-Kamha

Theses and Dissertations

In this thesis we present a technique to group search-engine returned citations for person-name queries, such that the search-engine returned citations in each group belong to the same person. To group the returned citations we use a multi-faceted approach that considers evidence from three facets: (1) attributes, (2) links, and (3) page similarity. For each facet we generate a confidence matrix. Then we construct a final confidence matrix for all facets. Using a threshold, we apply a grouping algorithm on the final confidence matrix. The output is a group of search-engine returned citations, such that the citations in each group …


Load Balancing Parallel Explicit State Model Checking, Rahul Kumar Jun 2004

Load Balancing Parallel Explicit State Model Checking, Rahul Kumar

Theses and Dissertations

This research first identifies some of the key concerns about the techniques and algorithms developed for distributed and parallel model checking; specifically, the inherent problem with load balancing and large queue sizes resultant in a static partition algorithm. This research then presents a load balancing algorithm to improve the run time performance in distributed model checking, reduce maximum queue size, and reduce the number of states expanded before error discovery. The load balancing algorithm is based on Generalized Dimension Exchange (GDE). This research presents an empirical analysis of the GDE based load balancing algorithm on three different supercomputing architectures---distributed memory …


Solving Large Mdps Quickly With Partitioned Value Iteration, David Wingate Jun 2004

Solving Large Mdps Quickly With Partitioned Value Iteration, David Wingate

Theses and Dissertations

Value iteration is not typically considered a viable algorithm for solving large-scale MDPs because it converges too slowly. However, its performance can be dramatically improved by eliminating redundant or useless backups, and by backing up states in the right order. We present several methods designed to help structure value dependency, and present a systematic study of companion prioritization techniques which focus computation in useful regions of the state space. In order to scale to solve ever larger problems, we evaluate all enhancements and methods in the context of parallelizability. Using the enhancements, we discover that in many instances the limiting …


Responding To Policies At Runtime In Trustbuilder, Bryan J. Smith Apr 2004

Responding To Policies At Runtime In Trustbuilder, Bryan J. Smith

Theses and Dissertations

Automated trust negotiation is the process of establishing trust between entities with no prior relationship through the iterative disclosure of digital credentials. One approach to negotiating trust is for the participants to exchange access control policies to inform each other of the requirements for establishing trust. When a policy is received at runtime, a compliance checker determines which credentials satisfy the policy so they can be disclosed. In situations where several sets of credentials satisfy a policy and some of the credentials are sensitive, a compliance checker that generates all the sets is necessary to insure that the negotiation succeeds …


Query Rewriting For Extracting Data Behind Html Forms, Xueqi Chen Apr 2004

Query Rewriting For Extracting Data Behind Html Forms, Xueqi Chen

Theses and Dissertations

Much of the information on the Web is stored in specialized searchable databases and can only be accessed by interacting with a form or a series of forms. As a result, enabling automated agents and Web crawlers to interact with form-based interfaces designed primarily for humans is of great value. This thesis describes a system that can fill out Web forms automatically according to a given user query against a global schema for an application domain and, to the extent possible, extract just the relevant data behind these Web forms. Experimental results on two application domains show that the approach …


Fast Registration Of Tabular Document Images Using The Fourier-Mellin Transform, Luke Alexander Daysh Hutchison Mar 2004

Fast Registration Of Tabular Document Images Using The Fourier-Mellin Transform, Luke Alexander Daysh Hutchison

Theses and Dissertations

Image registration, the process of finding the transformation that best maps one image to another, is an important tool in document image processing. Having properly-aligned microfilm images can help in manual and automated content extraction, zoning, and batch compression of images. An image registration algorithm is presented that quickly identifies the global affine transformation (rotation, scale, translation and/or shear) that maps one tabular document image to another, using the Fourier-Mellin Transform. Each component of the affine transform is recovered independantly from the others, dramatically reducing the parameter space of the problem, and improving upon standard Fourier-Mellin Image Registration (FMIR), which …