Denna rapport har jämfört olika path tracking-algoritmer för att se vilken som presterar bäst för spelagenter som färdas i konstant hastighet. Tre vanliga path tracking algoritmer som ofta används inom robotik har valts ut för undersökningen, Follow The Carrot, Pure Pursuit och Vector Pursuit. Algoritmerna har implementerats i C# och simuleringarna har genomförts i Unity 4.0. Path tracking-algoritmerna har testats på ett antal olika vägar för att se hur de lyckas följa vägen. Av simuleringarna så visar det sig att Pure Pursuit och Vector Pursuit presterade likvärdigt för spelagenter i konstant hastighet samt att de presterade bättre än Follow The Carrot.

In this thesis we are investigating a different formalism of non-relativistic quantum mechanics called the path integral formalism. It is a generalization of the classical least action principle. The introduction to this subject begins with the construction of the path integral in terms of the idea of probability amplitudes whose absolute square gives the probability of finding a system in a particular state. Then we show that if the Lagrangian is a quadratic form one needs only to calculate the classical action besides from a time-dependent normalization constant to find the explicit expression of the path integral. We look in to the subject of two kinds of slit-experiments: The square slit, the single- and the double-Gaussian slit. Also, the propagator for constrained paths is calculated and applied to the Aharonov-Bohm effect, which shows that the vector potential defined in classical electrodynamics have a physical meaning in quantum mechanics. It is also shown that the path integral formulation is equivalent to the Schrödinger description of quantum mechanics, by deriving the Schrödinger equation from the path integral. Further applications of the path integral are discussed. / I detta fördjupningsarbete undersöker vi en annan formalism av icke-relativistisk kvantmekanik kallad banintegral formalismen. Det är en generalisering av den klassiska verkansprincipen. Introduktionen till detta ämne börjar med konstruktionen av banintegralen i termer av sannolikhetsamplituder vars absolutbelopp i kvadrat ger sannolikheten av att finna ett system i ett särskilt tillstånd. Sedan visar vi att om Lagrangianen är av kvadratisk form så krävs endast en beräkning av den klassiska verkan förutom en tidsberoende normaliseringskonstant för att finna ett uttryck för banintegralen. Vi ser på två olika typer av spaltproblem: Den kantinga spalten, enkel- och dubbel Gaussisk spalt. Vi beräknar dessutom propagatorn för banor med restriktioner och applicerar detta på Aharonov-Bohm effekten, som visar att den klassiska vektorpotentialen som definierad i klassisk elektrodynamik har en fysikalisk mening i kvantmekaniken. Vi visar också ekvivalensen av banintegralformalismen med Schrödingerekvationen genom att härleda Schrödingerekvationen från banintegralen. Andra applikationer av banintegralen diskuteras.

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The purpose of this research was to design a multiple UAV system with collaborative operation. This project is built on work that has been done in the field of Unmanned Systems at VCU and is aimed at providing a starting point for research into collaborative control of multiple UAVs. The current GCS software was extended to include multiple vehicles per single controller via a new communication protocol. Many changes were made to the user interface to facilitate controlling multiple vehicles with a single operator. A second processor, called an MCS, was added to each vehicle to allow for greater flexibility and processing power, while maintaining backwards-compatibility and limiting infringement on the real-time processing of the FCS itself. The system was fully simulated via both hardware and software simulators, and ultimately the system was field tested using multiple vehicles collaboratively searching a defined area.

Global Navigation Satellite Systems can provide position, velocity and time information to users using receiver hardware. The United States developed Global Positioning System (GPS) is the only current fully operational system; however further systems are in development. The GPS has shown considerable success for navigation, but it still has a number of problems that limit its accuracy. The two main problems are the ionosphere and local environment of the receiver. The ionosphere causes a delay and random rapid shifts in phase and amplitude (scintillation) to the signal. The local environment can provide the signal with multiple routes (multi-path) to the receiver. In this project a GPS signal simulator is developed, which models the effects of the ionosphere and multi-path on the modulated signals. The focus is made on the GPS system as the simulator measurements can be compared to the real measurements; however other systems will be considered in the future. A number of experiments investigating multi-path and ionospheric effects on a receiver’s ability to track the signals have been completed. The simulator has been used to replicate a real local multi-path environment and the results have been compared. Further investigations of the multi-path have shown a unique multi-path signature in the receiver power output. The later part of the thesis describes a case study investigating a short but rapid period of scintillation observed on three receivers based in Norway. An analysis of the multi-path environment was completed, but was found not to be the cause. The ionosphere was investigated using equipment based across Scandinavia. The equipment showed that geomagnetic conditions were disturbed at the time of the event. The GPS measurements were compared with all-sky camera data to show that the scintillation can be attributed to the GPS signal path crossing electron density structures associated with the aurora.

How does the brain convert sensory information into abstract representations that can support complex behaviours? The rodent head-direction (HD) system, whose cell ensembles represent head direction in the horizontal plane, is a striking example of a “cognitive” representation without a direct sensory correlate. It can be updated by sensory inputs fromdifferentmodalities, yet persists in the absence of external input. Together with cells tuned for place, the HD system is thought to be fundamental for navigation and spatial information processing. However, relatively few studies have sought to characterise the connection between the HD system and spatial behaviour directly, and their overall outcome has been inconclusive. In the experiments that make up the first part of this thesis, we approach this issue by isolating the self-motion component of the HDsystem. We developed an (angular) path integration task in which we show that rats rely on their internal sense of direction to return to a trial-unique starting location, allowing us to investigate the contribution of the HD system to this behaviour without influences from uncontrolled external cues. Using this path integration task, we show that rats with bilateral lesions of the lateral mammillary nuclei (LMN) are significantly impaired compared to sham-operated controls. Lesions of the LMN, which contains HDcells, are known to abolish directional firing in downstream HD areas, suggesting that impairment on the task is due to loss of HD activity. We also recorded HD cell activity as rats are performing the path integration task, and found the HD representation to correlate with the rats’ choice of return journey. Thus, we provide both causal and correlational experimental evidence for a critical role of the HD system in path integration. For the second part of this thesis, we implemented a computational model of how the HD system is updated by head movements during path integration, providing a novel explanation for HD cells’ ability to anticipate the animal’s head direction. The model predicts that such anticipatory time intervals (ATIs) should depend on the frequency spectrum of the rats’ head movements. In direct comparison with experimental recording data, we show that the model can explain up to 80% of the experimentally observed variance, where none was explained by previous models. We also consider the effects of propagating the HD signal through multiple layers, identifying several potential sources of anticipation and lag. In summary, this thesis provides behavioural, lesion, and unit-recording evidence that during path integration, rats use a directional signal provided by the head direction system. The neural mechanisms responsible for the generation and maintenance of this signal are explored computationally. The finding that ATIs depend on the statistics of head movements has methodological implications and constrains models of the HD system.

The web provides a lot of fluid information but this information changes, moves, and even disappears over time. Bookmark lists, portals, and paths are collections where the building blocks are web pages, which are susceptible to these changes. A lot of research, both in industry and in academia, focuses on organizing this vast amount of data. In this thesis, I present context-based algorithms for measuring changes to a document. The methods proposed use other documents in a collection as the context for evaluating changes in the web pages. These metrics will be used in maintaining paths as the individual pages in paths change. This approach will enhance the evaluations of change made by the currently existing Path Manager, in the Walden's Paths project that is being developed in the Center for the Study of Digital Libraries at Texas A&M University.

No description available.

Immanants are a generalization of the well-studied determinant and permanent. Although the combinatorial interpretations for the determinant and permanent have been studied in excess, there remain few combinatorial interpretations for the immanant. The main objective of this thesis is to consider the immanant, and its possible combinatorial interpretations, in terms of recursive structures on the character. This thesis presents a comprehensive view of previous interpretations of immanants. Furthermore, it discusses algebraic techniques that may be used to investigate further into the combinatorial aspects of the immanant. We consider the Temperley-Lieb algebra and the class of immanants over the elements of this algebra. Combinatorial tools including the Temperley-Lieb algebra and Kauffman diagrams will be used in a number of interpretations. In particular, we extend some results for the permanent and determinant based on the $R$-weighted planar network construction, where $R$ is a convenient ring, by Clearman, Shelton, and Skandera. This thesis also presents some cases in which this construction cannot be extended. Finally, we present some extensions to combinatorial interpretations on certain classes of tableaux, as well as certain classes of matrices.

This study via the literatures and expert¡¦s interviews to explore the currently problems of new venture incubator to domestic Web2.0 industry, then try to offer the helpful suggestion. First, the way of analyzing literatures and correlating dates, can get the general problems during enterprise. This study focus on the pre start up stage and start up stage then choose the controllable factors and made the chosen factor as the content of expert¡¦s interview. This study chosen four factors ¡§the path of enterprise¡¨,¡¨ the recourses of enterprise¡¨, ¡§specific assistance of enterprise¡¨, ¡§the enterprise team¡¨ as the basic analyzing frame, , and get the results through expert¡¦s interview. By this study find out enterprise behavior can receive a appreciable profit. Recently, the industry orientations have gradually changed from labor-intensive industry to knowledge-intensive industry, and the information technology and infrastructure are nearly complete. Therefore this study chooses Web2.0 industry as research target. To observe the current circumstance of domestic enterprise assistance system can acquire preliminary phenomenon that current assistance system is lack of resource of pre start up stage and start up stage. It always makes enterprise behavior vanish even if the enterprisers have a fantasy idea. Comparatively a foreign country as U.S.A has lots of assistance institutions in connection with Web2.0 enterprise and has assisted the enterpriser establishes the company. Therefore, this study hopes to design an ideal model for domestic Web2.0 industry.