Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Keyword
-
- #antcenter (10)
- Machine learning (7)
- Artificial intelligence (5)
- Computer science (5)
- Computer networks--Security measures (4)
-
- UAV (3)
- Ant-inspired algorithms (2)
- Ants--Behavior--Mathematical models (2)
- Authentication (2)
- Autonomous robots--Mathematical models (2)
- Command and control systems (2)
- Computer graphics (2)
- Computer network protocols (2)
- Computer security (2)
- Computer viruses (2)
- Database security (2)
- Ensembles (2)
- Internet (2)
- Mathematical optimization (2)
- Model checking (2)
- Robots--Control systems (2)
- Software protection (2)
- TCP/IP (Computer network protocol) (2)
- Thesis (2)
- Training (2)
- Wireless communication systems (2)
- 3D interface (1)
- 802.11 (1)
- AI-based animation (1)
- Abstract matching (1)
Articles 1 - 30 of 72
Full-Text Articles in Physical Sciences and Mathematics
A Unified Framework For Solving Multiagent Task Assignment Problems, Kevin Cousin
A Unified Framework For Solving Multiagent Task Assignment Problems, Kevin Cousin
Theses and Dissertations
Multiagent task assignment problem descriptors do not fully represent the complex interactions in a multiagent domain, and algorithmic solutions vary widely depending on how the domain is represented. This issue is compounded as related research fields contain descriptors that similarly describe multiagent task assignment problems, including complex domain interactions, but generally do not provide the mechanisms needed to solve the multiagent aspect of task assignment. This research presents a unified approach to representing and solving the multiagent task assignment problem for complex problem domains. Ideas central to multiagent task allocation, project scheduling, constraint satisfaction, and coalition formation are combined to …
A Hybrid Multi-Robot Control Architecture, Daylond J. Hooper
A Hybrid Multi-Robot Control Architecture, Daylond J. Hooper
Theses and Dissertations
Multi-robot systems provide system redundancy and enhanced capability versus single robot systems. Implementations of these systems are varied, each with specific design approaches geared towards an application domain. Some traditional single robot control architectures have been expanded for multi-robot systems, but these expansions predominantly focus on the addition of communication capabilities. Both design approaches are application specific and limit the generalizability of the system. This work presents a redesign of a common single robot architecture in order to provide a more sophisticated multi-robot system. The single robot architecture chosen for application is the Three Layer Architecture (TLA). The primary strength …
Web Based Resource Management For Multi-Tiered Web Applications, Bryce Daniel Ott
Web Based Resource Management For Multi-Tiered Web Applications, Bryce Daniel Ott
Theses and Dissertations
The currently emerging trend of building more complex web applications to solve increasingly more involved software problems has led to the the need for a more automated and practical means for deploying resources required by these advanced web applications. As web based applications become more complex and involve more developers, greater system redundancy, and a larger number of components, traditional means of resource deployment become painfully inadequate as they fail to scale sufficiently. The purpose of this research is to provide evidence that a more sound and scalable test and deployment process can be employed and that many of the …
Route Validation Using Radio Frequency Identification, William T. Watson
Route Validation Using Radio Frequency Identification, William T. Watson
Theses and Dissertations
In recent years, radio frequency identification (RFID) has been proposed and implemented in a variety of applications where tracking objects, animals or people is desirable. This paper proposes a novel approach to the application of RFID tech- nology in those applications where it is possible to validate a person or an object's passive contact with a given or arbitrary set of fixed points along a predefined route. The notable departure from the typical application of RFID technology is that in this scheme, the transponders are permanently installed while the interrogator is affixed to a person or object that travels the …
Rss Management: An Rss Reader To Manage Rss Feeds That Efficiently And Effectively Pulls And Filters Feeds With Minimal Bandwidth Consumption, Brian Cooper
Theses and Dissertations
In the early 2000s, RSS (Really Simple Syndication) was launched into cyber space and rapidly gained fame by existing as the underlying technology that fueled millions of web logs (blogs). Soon RSS feeds appeared for news, multimedia podcasting, and many other types of information on the Internet. RSS introduced a new way to syndicate information that allowed anyone interested to subscribe to published content and pull the information to an aggregator, (RSS reader application), at their discretion. RSS made it simple for people to keep up with online content without having to continuously check websites for new content. This new …
Malicious Mobile Code Related Experiments With An Extensible Network Simulator, Attila Ondi
Malicious Mobile Code Related Experiments With An Extensible Network Simulator, Attila Ondi
Theses and Dissertations
The automated spread of worms such as Code-Red, SQL/Slammer, and Nimda have caused costly problems to computers connected to the Internet. Even users whose machines were not vulnerable to these threats suffered a loss of productivity and experienced great frustration as connectivity and network traffic were negatively impacted during outbreaks. Although the number of new worm attacks reported in the media seems to be declining, it is vital that researchers study the effects of malicious code on the global network to understand how to defend against future threats. The choice of system for studying the spread of worms and viruses …
A Direct Algorithm For The K-Nearest-Neighbor Classifier Via Local Warping Of The Distance Metric, Tohkoon Neo
A Direct Algorithm For The K-Nearest-Neighbor Classifier Via Local Warping Of The Distance Metric, Tohkoon Neo
Theses and Dissertations
The k-nearest neighbor (k-NN) pattern classifier is a simple yet effective learner. However, it has a few drawbacks, one of which is the large model size. There are a number of algorithms that are able to condense the model size of the k-NN classifier at the expense of accuracy. Boosting is therefore desirable for increasing the accuracy of these condensed models. Unfortunately, there does not exist a boosting algorithm that works well with k-NN directly. We present a direct boosting algorithm for the k-NN classifier that creates an ensemble of models with locally modified distance weighting. An empirical study conducted …
Supporting Flight Control For Uav-Assisted Wilderness Search And Rescue Through Human Centered Interface Design, Joseph L. Cooper
Supporting Flight Control For Uav-Assisted Wilderness Search And Rescue Through Human Centered Interface Design, Joseph L. Cooper
Theses and Dissertations
Inexpensive, rapidly deployable, camera-equipped Unmanned Aerial Vehicle (UAV) systems can potentially assist with a huge number of tasks. However, in many cases such as wilderness search and rescue (WiSAR), the potential users of the system may not be trained as pilots. Simple interface concepts can be used to build an interaction layer that allows an individual with minimal operator training to use the system to facilitate a search or inspection task. We describe an analysis of WiSAR as currently accomplished and show how a UAV system might fit into the existing structure. We then discuss preliminary system design efforts for …
Intersection Algorithms Based On Geometric Intervals, Nicholas Stewart North
Intersection Algorithms Based On Geometric Intervals, Nicholas Stewart North
Theses and Dissertations
This thesis introduces new algorithms for solving curve/curve and ray/surface intersections. These algorithms introduce the concept of a geometric interval to extend the technique of Bézier clipping. A geometric interval is used to tightly bound a curve or surface or to contain a point on a curve or surface. Our algorithms retain the desirable characteristics of the Bézier clipping technique such as ease of implementation and the guarantee that all intersections over a given interval will be found. However, these new algorithms generally exhibit cubic convergence, improving on the observed quadratic convergence rate of Bézier clipping. This is achieved without …
Heuristic Weighted Voting, Kristine Perry Monteith
Heuristic Weighted Voting, Kristine Perry Monteith
Theses and Dissertations
Selecting an effective method for combining the votes of classifiers in an ensemble can have a significant impact on the overall classification accuracy an ensemble is able to achieve. With some methods, the ensemble cannot even achieve as high a classification accuracy as the most accurate individual classifying component. To address this issue, we present the strategy of Heuristic Weighted Voting, a technique that uses heuristics to determine the confidence that a classifier has in its predictions on an instance by instance basis. Using these heuristics to weight the votes in an ensemble results in an overall average increase in …
Limitations And Extensions Of The Wolf-Phc Algorithm, Philip R. Cook
Limitations And Extensions Of The Wolf-Phc Algorithm, Philip R. Cook
Theses and Dissertations
Policy Hill Climbing (PHC) is a reinforcement learning algorithm that extends Q-learning to learn probabilistic policies for multi-agent games. WoLF-PHC extends PHC with the "win or learn fast" principle. A proof that PHC will diverge in self-play when playing Shapley's game is given, and WoLF-PHC is shown empirically to diverge as well. Various WoLF-PHC based modifications were created, evaluated, and compared in an attempt to obtain convergence to the single shot Nash equilibrium when playing Shapley's game in self-play without using more information than WoLF-PHC uses. Partial Commitment WoLF-PHC (PCWoLF-PHC), which performs best on Shapley's game, is tested on other …
Improving Neural Network Classification Training, Michael Edwin Rimer
Improving Neural Network Classification Training, Michael Edwin Rimer
Theses and Dissertations
The following work presents a new set of general methods for improving neural network accuracy on classification tasks, grouped under the label of classification-based methods. The central theme of these approaches is to provide problem representations and error functions that more directly improve classification accuracy than conventional learning and error functions. The CB1 algorithm attempts to maximize classification accuracy by selectively backpropagating error only on misclassified training patterns. CB2 incorporates a sliding error threshold to the CB1 algorithm, interpolating between the behavior of CB1 and standard error backpropagation as training progresses in order to avoid prematurely saturated network weights. CB3 …
Scaling Ant Colony Optimization With Hierarchical Reinforcement Learning Partitioning, Erik J. Dries
Scaling Ant Colony Optimization With Hierarchical Reinforcement Learning Partitioning, Erik J. Dries
Theses and Dissertations
This research merges the hierarchical reinforcement learning (HRL) domain and the ant colony optimization (ACO) domain. The merger produces a HRL ACO algorithm capable of generating solutions for both domains. This research also provides two specific implementations of the new algorithm: the first a modification to Dietterich's MAXQ-Q HRL algorithm, the second a hierarchical ACO algorithm. These implementations generate faster results, with little to no significant change in the quality of solutions for the tested problem domains. The application of ACO to the MAXQ-Q algorithm replaces the reinforcement learning, Q-learning and SARSA, with the modified ant colony optimization method, Ant-Q. …
Multi-Objective Optimization For Speed And Stability Of A Sony Aibo Gait, Christopher A. Patterson
Multi-Objective Optimization For Speed And Stability Of A Sony Aibo Gait, Christopher A. Patterson
Theses and Dissertations
Locomotion is a fundamental facet of mobile robotics that many higher level aspects rely on. However, this is not a simple problem for legged robots with many degrees of freedom. For this reason, machine learning techniques have been applied to the domain. Although impressive results have been achieved, there remains a fundamental problem with using most machine learning methods. The learning algorithms usually require a large dataset which is prohibitively hard to collect on an actual robot. Further, learning in simulation has had limited success transitioning to the real world. Also, many learning algorithms optimize for a single fitness function, …
Collaborative, Trust-Based Security Mechanisms For A National Utility Intranet, Gregory M. Coates
Collaborative, Trust-Based Security Mechanisms For A National Utility Intranet, Gregory M. Coates
Theses and Dissertations
This thesis investigates security mechanisms for utility control and protection networks using IP-based protocol interaction. It proposes flexible, cost-effective solutions in strategic locations to protect transitioning legacy and full IP-standards architectures. It also demonstrates how operational signatures can be defined to enact organizationally-unique standard operating procedures for zero failure in environments with varying levels of uncertainty and trust. The research evaluates layering encryption, authentication, traffic filtering, content checks, and event correlation mechanisms over time-critical primary and backup control/protection signaling to prevent disruption by internal and external malicious activity or errors. Finally, it shows how a regional/national implementation can protect private …
Parallelization Of Ant Colony Optimization Via Area Of Expertise Learning, Adrian A. De Freitas
Parallelization Of Ant Colony Optimization Via Area Of Expertise Learning, Adrian A. De Freitas
Theses and Dissertations
Ant colony optimization algorithms have long been touted as providing an effective and efficient means of generating high quality solutions to NP-hard optimization problems. Unfortunately, while the structure of the algorithm is easy to parallelize, the nature and amount of communication required for parallel execution has meant that parallel implementations developed suffer from decreased solution quality, slower runtime performance, or both. This thesis explores a new strategy for ant colony parallelization that involves Area of Expertise (AOE) learning. The AOE concept is based on the idea that individual agents tend to gain knowledge of different areas of the search space …
A Framework For Analyzing And Mitigating The Vulnerabilities Of Complex Systems Via Attack And Protection Trees, Kenneth S. Edge
A Framework For Analyzing And Mitigating The Vulnerabilities Of Complex Systems Via Attack And Protection Trees, Kenneth S. Edge
Theses and Dissertations
Attack trees have been developed to describe processes by which malicious users attempt to exploit or break complex systems. Attack trees offer a method of decomposing, visualizing, and determining the cost or likelihood of attacks. Attack trees by themselves do not provide enough decision support to system defenders. This research develops the concept of using protection trees to offer a detailed risk analysis of a system. In addition to developing protection trees, this research improves the existing concept of attack trees and develops rule sets for the manipulation of metrics used in the security of complex systems. This research specifically …
Ontology Aware Software Service Agents: Meeting Ordinary User Needs On The Semantic Web, Muhammed Jassem Al Muhammed
Ontology Aware Software Service Agents: Meeting Ordinary User Needs On The Semantic Web, Muhammed Jassem Al Muhammed
Theses and Dissertations
To achieve the dream of the semantic web, it must be possible for ordinary users to invoke services. It is clear that users need simple-to-invoke-and-use services. This dissertation offers an ontological approach to declaratively create services that users can invoke using free-form, natural-language-like specifications. Our approach uses task ontologies as foundational knowledge. A task ontology consists of a domain ontology and a process ontology. The domain ontology encodes domain information such as possible constraints and instances in terms of object sets, relationship sets among these object sets, and operations over values in object sets and relationship sets. The process ontology …
The Spillable Environment: Expanding A Handheld Device's Screen Real Estate And Interactive Capabilities, Jeffrey S. Clement
The Spillable Environment: Expanding A Handheld Device's Screen Real Estate And Interactive Capabilities, Jeffrey S. Clement
Theses and Dissertations
Handheld devices have a limited amount of screen real estate. If a handheld device could take advantage of larger screens, it would create a more powerful user interface and environment. As time progresses, Moore's law predicts that the computational power of handheld devices will increase dramatically in the future, promoting the interaction with a larger screen. Users can then use their peripheral vision to recognize spatial relationships between objects and solve problems more easily with this integrated system. In the spillable environment, the handheld device uses a DiamondTouch Table, a large, touch-sensitive horizontal table, to enhance the viewing environment. When …
Text Identification By Example, Daniel Joseph Preece
Text Identification By Example, Daniel Joseph Preece
Theses and Dissertations
The World-Wide Web contains a lot of information and reading through the web pages to collect this information is tedious, time consuming and error prone. Users need an automated solution for extracting or highlighting the data that they are interested in. Building a regular expression to match the text they are interested in will automate the process, but regular expressions are hard to create and certainly are not feasible for non-programmers to construct. Text Identification by Example (TIBE) makes it easier for end-users to harvest information from the web and other text documents. With TIBE, training text classifiers from user-selected …
Sampling Methods In Ray-Based Global Illumination, David Cline
Sampling Methods In Ray-Based Global Illumination, David Cline
Theses and Dissertations
In computer graphics, algorithms that attempt to create photographic images by simulating light transport are collectively known as Global Illumination methods. The most versatile of these are based on ray tracing (following ray paths through a scene), and numerical integration using random or quasi-random sampling. While ray tracing and sampling methods in global illumination have progressed much in the last two decades, the goal of fast and accurate simulation of light transport remains elusive. This dissertation presents a number of new sampling methods that attempt to address some of the shortcomings of existing global illumination algorithms. The first part of …
Or Best Offer: A Privacy Policy Negotiation Protocol, Daniel David Walker
Or Best Offer: A Privacy Policy Negotiation Protocol, Daniel David Walker
Theses and Dissertations
Users today are concerned about how their information is collected, stored and used by Internet sites. Privacy policy languages, such as the Platform for Privacy Preferences (P3P), allow websites to publish their privacy practices and policies in machine readable form. Currently, software agents designed to protect users' privacy follow a "take it or leave it" approach when evaluating these privacy policies. This approach is inflexible and gives the server ultimate control over the privacy of web transactions. Privacy policy negotiation is one approach to leveling the playing field by allowing a client to negotiate with a server to determine how …
Extensible Pre-Authentication In Kerberos, Phillip L. Hellewell
Extensible Pre-Authentication In Kerberos, Phillip L. Hellewell
Theses and Dissertations
Organizations need to provide services to a wide range of people, including strangers outside their local security domain. As the number of users grows larger, it becomes increasingly tedious to maintain and provision user accounts. It remains an open problem to create a system for provisioning outsiders that is secure, flexible, efficient, scalable, and easy to manage. Kerberos is a secure, industry-standard protocol. Currently, Kerberos operates as a closed system; all users must be specified upfront and managed on an individual basis. This paper presents EPAK (Extensible Pre-Authentication in Kerberos), a framework that enables Kerberos to operate as an open …
Obstacle Avoidance And Path Traversal Using Interactive Machine Learning, Jonathan M. Turner
Obstacle Avoidance And Path Traversal Using Interactive Machine Learning, Jonathan M. Turner
Theses and Dissertations
Recently there has been a growing interest in using robots in activities that are dangerous or cost prohibitive for humans to do. Such activities include military uses and space exploration. While robotic hardware is often capable of being used in these types of situations, the ability of human operators to control robots in an effective manner is often limited. This deficiency is often related to the control interface of the robot and the level of autonomy that control system affords the human operator. This thesis describes a robot control system, called the safe/unsafe system, which gives a human operator the …
Conceptual Xml For Systems Analysis, Reema Al-Kamha
Conceptual Xml For Systems Analysis, Reema Al-Kamha
Theses and Dissertations
Because XML has become a new standard for data representation, there is a need for a simple conceptual model that works well with XML-based development. In this research we present a conceptual model for XML, called C-XML, which meets this new need of systems analysts who store their data using XML. We describe our implementation of an automatic conversion from XML Schema to C-XML that preserves information and constraints. With this conversion, we can view an XML Schema instance graphically at a higher level of abstraction. We also describe our implementation of an automatic conversion from C-XML to XML Schema. …
Efficient Gps Position Determination Algorithms, Thao Nguyen
Efficient Gps Position Determination Algorithms, Thao Nguyen
Theses and Dissertations
This research is aimed at improving the state of the art of GPS algorithms, namely, the development of a closed-form positioning algorithm for a standalone user and the development of a novel differential GPS algorithm for a network of users. The stand-alone user GPS algorithm is a direct, closed-form, and efficient new position determination algorithm that exploits the closed-form solution of the GPS trilateration equations and works in the presence of pseudorange measurement noise for an arbitrary number of satellites in view. A two-step GPS position determination algorithm is derived which entails the solution of a linear regression and updates …
Intelligent Rotoscoping: A Semi-Automated Interactive Boundary Tracking Approach To Video Segmentation, Seth R. Holladay
Intelligent Rotoscoping: A Semi-Automated Interactive Boundary Tracking Approach To Video Segmentation, Seth R. Holladay
Theses and Dissertations
Video segmentation is an application of computer vision aimed at automating the extraction of an object from a series of video frames. However, it is a difficult problem, especially to compute at real-time, interactive rates. Although general application to video is difficult because of the wide range of image scenarios, user interaction can help to reduce the problem space and speed up the computation. This thesis presents a fast object-tracking tool that selects an object from a series of frames based on minimal user input. Our Intelligent Rotoscoping tool aims for increased speed and accuracy over other video segmentation tools, …
Finding Termination And Time Improvement In Predicate Abstraction With Under-Approximation And Abstract Matching, Dritan Kudra
Finding Termination And Time Improvement In Predicate Abstraction With Under-Approximation And Abstract Matching, Dritan Kudra
Theses and Dissertations
The focus of current formal verification methods is mitigating the state explosion problem. One of these formal methods is predicate abstraction, which reduces concrete states of a system to bitvectors of true/false valuations of a set of predicates. Predicate abstraction comes in two flavors, over-approximation and under-approximation. A drawback of over-approximation is that it produces too many spurious errors for data-intensive applications. A more recent under-approximation technique which does not produce spurious errors, does abstract matching on concrete states (AMCS). AMCS adds behaviors to an abstract system by augmenting the set of initial predicates, making use of a theorem prover. …
Cognitive And Behavioral Model Ensembles For Autonomous Virtual Characters, Jeffrey S. Whiting
Cognitive And Behavioral Model Ensembles For Autonomous Virtual Characters, Jeffrey S. Whiting
Theses and Dissertations
Cognitive and behavioral models have become popular methods to create autonomous self-animating characters. Creating these models presents the following challenges: (1) Creating a cognitive or behavioral model is a time intensive and complex process that must be done by an expert programmer (2) The models are created to solve a specific problem in a given environment and because of their specific nature cannot be easily reused. Combining existing models together would allow an animator, without the need of a programmer, to create new characters in less time and would be able to leverage each model's strengths to increase the character's …
Vision-Based Control And Flight Optimization Of A Rotorcraft Uav, David Christian Hubbard
Vision-Based Control And Flight Optimization Of A Rotorcraft Uav, David Christian Hubbard
Theses and Dissertations
A Rotorcraft UAV provides an ideal experimental platform for vision-based navigation. This thesis describes the flight tests of the US Army PALACE pro ject, which implements Moravec's pseudo-normalized correlation tracking algorithm. The tracker uses the movement of the landing site in the camera, a laser range, and the aircraft attitude from an IMU to estimate the relative motion of the UAV. The position estimate functions as a GPS equivalent to enable the rotorcraft to maneuver without the aid of GPS. Flight tests were performed with obstacles and over concrete, asphalt, and grass in daylight conditions with a safe landing area …