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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Optical Characterization Of Ferromagnetic And Multiferroic Thin-Film Heterostructures, Xin Ma
Optical Characterization Of Ferromagnetic And Multiferroic Thin-Film Heterostructures, Xin Ma
Dissertations, Theses, and Masters Projects
This thesis presents optical characterization of the static and dynamic magnetic interactions in ferromagnetic and multiferroic heterostructures with time-resolved and interface-specific optical techniques. The focus of the thesis is on elucidating the underlying physics of key physical parameters and novel approaches, crucial to the performance of magnetic recording and spintronic devices.;First, time-resolved magneto-optical Kerr effect (TRMOKE) is applied to investigate the spin dynamics in L10 ordered FePt thin films, where perpendicular magnetic anisotropy Ku and intrinsic Gilbert damping alpha0 are determined. Furthermore, the quadratic dependence of Ku and alpha0 on spin-orbit coupling strength xi is demonstrated, where xi is continuously …
Classification Of Non-Heat Generating Outdoor Objects In Thermal Scenes For Autonomous Robots, William L. Fehlman
Classification Of Non-Heat Generating Outdoor Objects In Thermal Scenes For Autonomous Robots, William L. Fehlman
Dissertations, Theses, and Masters Projects
We have designed and implemented a physics-based adaptive Bayesian pattern classification model that uses a passive thermal infrared imaging system to automatically characterize non-heat generating objects in unstructured outdoor environments for mobile robots. In the context of this research, non-heat generating objects are defined as objects that are not a source for their own emission of thermal energy, and so exclude people, animals, vehicles, etc. The resulting classification model complements an autonomous bot's situational awareness by providing the ability to classify smaller structures commonly found in the immediate operational environment. Since GPS depends on the availability of satellites and onboard …
Sonar Sensor Interpretation For Ectogeneous Robots, Wen Gao
Sonar Sensor Interpretation For Ectogeneous Robots, Wen Gao
Dissertations, Theses, and Masters Projects
We have developed four generations of sonar scanning systems to automatically interpret surrounding environment. The first two are stationary 3D air-coupled ultrasound scanning systems and the last two are packaged as sensor heads for mobile robots. Template matching analysis is applied to distinguish simple indoor objects. It is conducted by comparing the tested echo with the reference echoes. Important features are then extracted and drawn in the phase plane. The computer then analyzes them and gives the best choices of the tested echoes automatically. For cylindrical objects outside, an algorithm has been presented to distinguish trees from smooth circular poles …
Automated Fish Species Classification Using Artificial Neural Networks And Autonomous Underwater Vehicles, Daniel Foster Doolittle
Automated Fish Species Classification Using Artificial Neural Networks And Autonomous Underwater Vehicles, Daniel Foster Doolittle
Dissertations, Theses, and Masters Projects
No abstract provided.
Ann Wave Prediction Model For Winter Storms And Hurricanes, Jun-Young. Kim
Ann Wave Prediction Model For Winter Storms And Hurricanes, Jun-Young. Kim
Dissertations, Theses, and Masters Projects
Currently available wind-wave prediction models require a prohibitive amount of computing time for simulating non-linear wave-wave interactions. Moreover, some parts of wind-wave generation processes are not fully understood yet. For this reason accurate predictions are not always guaranteed. In contrast, Artificial Neural Network (ANN) techniques are designed to recognize the patterns between input and output so that they can save considerable computing time so that real-time wind-wave forecast can be available to the navy and commercial ships. For this reason, this study tries to use ANN techniques to predict waves for winter storms and hurricanes with much less computing time …
The Fusion And Integration Of Virtual Sensors, Thomas F. Litant
The Fusion And Integration Of Virtual Sensors, Thomas F. Litant
Dissertations, Theses, and Masters Projects
There are numerous sensors from which to choose when designing a mobile robot: ultrasonic, infrared, radar, or laser range finders, video, collision detectors, or beacon based systems such as the Global Positioning System. In order to meet the need for reliability, accuracy, and fault tolerance, mobile robot designers often place multiple sensors on the same platform, or combine sensor data from multiple platforms. The combination of the data from multiple sensors to improve reliability, accuracy, and fault tolerance is termed Sensor Fusion.;The types of robotic sensors are as varied as the properties of the environment that need to be sensed. …
A Grammar-Based Technique For Genetic Search And Optimization, Clayton Matthew Johnson
A Grammar-Based Technique For Genetic Search And Optimization, Clayton Matthew Johnson
Dissertations, Theses, and Masters Projects
The genetic algorithm (GA) is a robust search technique which has been theoretically and empirically proven to provide efficient search for a variety of problems. Due largely to the semantic and expressive limitations of adopting a bitstring representation, however, the traditional GA has not found wide acceptance in the Artificial Intelligence community. In addition, binary chromosones can unevenly weight genetic search, reduce the effectiveness of recombination operators, make it difficult to solve problems whose solution schemata are of high order and defining length, and hinder new schema discovery in cases where chromosome-wide changes are required.;The research presented in this dissertation …
General Methods For Analyzing Machine Learning Sample Complexity, Christoph Cornelius Michael
General Methods For Analyzing Machine Learning Sample Complexity, Christoph Cornelius Michael
Dissertations, Theses, and Masters Projects
During the past decade, there has been a resurgence of interest in applying mathematical methods to problems in artificial intelligence. Much work has been done in the field of machine learning, but it is not always clear how the results of this research should be applied to practical problems. Our aim is to help bridge the gap between theory and practice by addressing the question: "If we are given a machine learning algorithm, how should we go about formally analyzing it?" as opposed to the usual question: "how do we write a learning algorithm we can analyze?".;We will consider algorithms …
Design And Analysis Techniques For Concurrent Blackboard Systems, John William Mcmanus
Design And Analysis Techniques For Concurrent Blackboard Systems, John William Mcmanus
Dissertations, Theses, and Masters Projects
Blackboard systems are a natural progression of Artificial Intelligence based systems into a more powerful problem solving technique. They provide a way for several highly specialized knowledge sources to cooperate to solve large, complex problems. Blackboard systems incorporate the concepts developed by rule-based and expert systems programmers and include the ability to add conventionally coded knowledge sources. The small and specialized knowledge sources are easier to develop and test, and are hosted on hardware specifically suited to the task that they are solving.;Designing and developing blackboard systems is a difficult process. The designer is attempting to balance several conflicting goals …
Knowledge-Based System For Flight Information Management, Wendell R. Ricks
Knowledge-Based System For Flight Information Management, Wendell R. Ricks
Dissertations, Theses, and Masters Projects
No abstract provided.
Adaptation Of Lr Parsing To Production System Interpretation, Louis Paul Slothouber
Adaptation Of Lr Parsing To Production System Interpretation, Louis Paul Slothouber
Dissertations, Theses, and Masters Projects
This thesis presents such a new production system architecture, called a palimpsest parser, that adapts LR parsing technology to the process of controlled production system interpretation. Two unique characteristics of this architecture facilitate the construction and execution of large production systems: the rate at which productions fire is independent of production system size, and the modularity inherent in production systems is preserved and enhanced. In addition, individual productions may be evaluated in either a forward or backward direction, production systems can be integrated with other production systems and procedural programs, and production system modules can be compiled into libraries and …