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

Physical Sciences and Mathematics Commons™

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

LSU Doctoral Dissertations

Computer Sciences

2015

Articles 1 - 8 of 8

Full-Text Articles in Physical Sciences and Mathematics

Pattern Mining And Events Discovery In Molecular Dynamics Simulations Data, Shobhit Sandesh Shakya Jan 2015

Pattern Mining And Events Discovery In Molecular Dynamics Simulations Data, Shobhit Sandesh Shakya

LSU Doctoral Dissertations

Molecular dynamics simulation method is widely used to calculate and understand a wide range of properties of materials. A lot of research efforts have been focused on simulation techniques but relatively fewer works are done on methods for analyzing the simulation results. Large-scale simulations usually generate massive amounts of data, which make manual analysis infeasible, particularly when it is necessary to look into the details of the simulation results. In this dissertation, we propose a system that uses computational method to automatically perform analysis of simulation data, which represent atomic position-time series. The system identifies, in an automated fashion, the …

Go to article

A Trust-Based Relay Selection Approach To The Multi-Hop Network Formation Problem In Cognitive Radio Networks, Brandy Michelle Tyson Jan 2015

A Trust-Based Relay Selection Approach To The Multi-Hop Network Formation Problem In Cognitive Radio Networks, Brandy Michelle Tyson

LSU Doctoral Dissertations

One of the major challenges for today’s wireless communications is to meet the growing demand for supporting an increasing diversity of wireless applications with limited spectrum resource. In cooperative communications and networking, users share resources and collaborate in a distributed approach, similar to entities of active social groups in self organizational communities. Users’ information may be shared by the user and also by the cooperative users, in distributed transmission. Cooperative communications and networking is a fairly new communication paradigm that promises significant capacity and multiplexing gain increase in wireless networks. This research will provide a cooperative relay selection framework that …

Go to article

Real-Time Shadows For Gigapixel Displacement Maps, Kevin Anthony Cherry Jan 2015

Real-Time Shadows For Gigapixel Displacement Maps, Kevin Anthony Cherry

LSU Doctoral Dissertations

Shadows portray helpful information in scenes. From a scientific visualization standpoint, they help to add data without unnecessary clutter. In video games they add realism and depth. In common graphics pipelines, due to the independent and parallel rendering of geometric primitives, shadows are difficult to achieve. Objects require knowledge of each other and therefore multiple renders are needed to collect the necessary data. The collection of this data comes with its own set of trade offs. Our research involves adding shadows into a lunar rendering framework developed by Dr. Robert Kooima. The NASA-collected data contains a multi-gigapixel displacement map describing …

Go to article

Classification In The Presence Of Ordered Classes And Weighted Evaluative Attributes, Forrest Justin Osterman Jan 2015

Classification In The Presence Of Ordered Classes And Weighted Evaluative Attributes, Forrest Justin Osterman

LSU Doctoral Dissertations

We are interested in an important family of problems in the interface of the Multi-Attribute Decision-Making and Data Mining fields. This is a special case of the general classification problem, in which records describing entities of interest have been expressed in terms of a number of evaluative attributes. These attributes are associated with weights of importance, and both the data and the classes are ordinal. Our goal is to use historical records and the corresponding decisions to best estimate the class values of new data points in a way consistent with prior classification decisions, without knowledge of the weights of …

Go to article

Seavipers - Computer Vision And Inertial Position Reference Sensor System (Cviprss), Justin Lee Erdman Jan 2015

Seavipers - Computer Vision And Inertial Position Reference Sensor System (Cviprss), Justin Lee Erdman

LSU Doctoral Dissertations

This work describes the design and development of an optical, Computer Vision (CV) based sensor for use as a Position Reference System (PRS) in Dynamic Positioning (DP). Using a combination of robotics and CV techniques, the sensor provides range and heading information to a selected reference object. The proposed optical system is superior to existing ones because it does not depend upon special reflectors nor does it require a lengthy set-up time. This system, the Computer Vision and Inertial Position Reference Sensor System (CVIPRSS, pronounced \nickname), combines a laser rangefinder, infrared camera, and a pan--tilt unit with the robust TLD …

Go to article

String Searching With Ranking Constraints And Uncertainty, Sudip Biswas Jan 2015

String Searching With Ranking Constraints And Uncertainty, Sudip Biswas

LSU Doctoral Dissertations

Strings play an important role in many areas of computer science. Searching pattern in a string or string collection is one of the most classic problems. Different variations of this problem such as document retrieval, ranked document retrieval, dictionary matching has been well studied. Enormous growth of internet, large genomic projects, sensor networks, digital libraries necessitates not just efficient algorithms and data structures for the general string indexing, but indexes for texts with fuzzy information and support for queries with different constraints. This dissertation addresses some of these problems and proposes indexing solutions. One such variation is document retrieval query …

Go to article

Synthesis With Hypergraphs, Christopher Thomas Alvin Jan 2015

Synthesis With Hypergraphs, Christopher Thomas Alvin

LSU Doctoral Dissertations

Many problems related to synthesis with intelligent tutoring may be phrased as program synthesis problems using AI-style search and formal reasoning techniques. The _x000C_first two results in this dissertation focus on problem synthesis as an aspect of intelligent tutoring systems applied to STEM-based education frameworks, specifically high school geometry. Given a geometric _x000C_figure as input, our technique constructs a hypergraph representing logical deduction of facts, and then traverses the hypergraph to synthesize problems and their corresponding solutions. Using similar techniques, our third result is focused on exhaustive synthesis of molecules. This synthesis process involves bonding sets of basic, molecular `fragments' …

Go to article

Large-Scale Geometric Data Decomposition, Processing And Structured Mesh Generation, Wuyi Yu Jan 2015

Large-Scale Geometric Data Decomposition, Processing And Structured Mesh Generation, Wuyi Yu

LSU Doctoral Dissertations

Mesh generation is a fundamental and critical problem in geometric data modeling and processing. In most scientific and engineering tasks that involve numerical computations and simulations on 2D/3D regions or on curved geometric objects, discretizing or approximating the geometric data using a polygonal or polyhedral meshes is always the first step of the procedure. The quality of this tessellation often dictates the subsequent computation accuracy, efficiency, and numerical stability. When compared with unstructured meshes, the structured meshes are favored in many scientific/engineering tasks due to their good properties. However, generating high-quality structured mesh remains challenging, especially for complex or large-scale …

Go to article