Various approaches are presented in the literature to identify faultprone components. The approaches represent a wide range of characteristics and capabilities, but they are not comparable, since different aspects are...
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In this paper we address the problem of designing energy minimizing collision-free maneuvers for multiple agents moving on a plane. We show that the problem is equivalent to that of finding the shortest geodesic in a ...
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Advances in VLSI technology have lead to a tremendous increase in the density and number of devices that can be manufactured in a single microchip. One of the interesting ways in which this silicon may be used is to l...
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A neuro-fuzzy (NF)-based adaptive controller is presented in this paper for the trajectory tracking control of a flexible-link space manipulator. Based on the singular perturbation method and two time-scale decomposit...
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A neuro-fuzzy (NF)-based adaptive controller is presented in this paper for the trajectory tracking control of a flexible-link space manipulator. Based on the singular perturbation method and two time-scale decompositions, the dynamic model of a flexible space robot is reduced into a slow subsystem of an equivalent rigid-link arm and a fast subsystem of flexible mode. A dynamic NF adaptive controller based on dynamic inversion is presented for the tracking control of the equivalent rigid arm, while a fuzzy proportional-derivative (PD) controller is used to stabilize the elastic dynamics. Finally, experiment studies are carried out to show the viability and effectiveness of the proposed control approach.
In this paper, we propose a method for detecting a traffic sign from a scene image in the daytime. This method uses Active Net in two steps. Active net is a deformable lattice network model which minimizes an energy f...
For some important network management applications, e.g., MIB browsing, there is a need to traverse portions of an MIB tree, especially tables, in both directions. While the GetNext request defined by the SNMP standar...
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Divide-and-conquer approximation algorithms for vertex ordering problems partition the vertex set of graphs, compute recursively an ordering of each part, and "glue" the orderings of the parts together. The ...
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Divide-and-conquer approximation algorithms for vertex ordering problems partition the vertex set of graphs, compute recursively an ordering of each part, and "glue" the orderings of the parts together. The computed ordering is specfied by a decomposition tree that describes the recursive partitioning of the subproblems. At each internal node of the decomposition tree, there is a degree of freedom regarding the order in which the parts are glued together. Approximation algorithms that use this technique ignore these degrees of freedom, and prove that the cost of every ordering that agrees with the computed decomposition tree is within the range specified by the approximation factor. We address the question of whether an optimal ordering can be efficiently computed among the exponentially many orderings induced by a binary decomposition tree. We present a polynomial time algorithm for computing an optimal ordering induced by a binary balanced decomposition tree with respect to two problems: Minimum Linear Arrangement (MINLA) and Minimum Cutwidth (MINCW). For 1/3-balanced decomposition trees of bounded degree graphs, the time complexity of our algorithm is O(n2:2), where n denotes the number of vertices. Additionally, we present experimental evidence that computing an optimal orientation of a decomposition tree is useful in practice. It is shown, through an implementation for MINLA, that optimal orientations of decomposition trees can produce arrangements of roughly the same quality as those produced by the best known heuristic, at a fraction of the running time.
We introduce a new paradigm for automatic medical image analysis that adopts concepts from the field of Artificial Life. Our approach prescribes deformable organisms, autonomous agents whose objective is the segmentat...
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This thesis studies several topics within the area of antennas and propagation from a signal processing perspective. However, theory and methods from electromagnetics and communications have also been used, contributi...
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This thesis studies several topics within the area of antennas and propagation from a signal processing perspective. However, theory and methods from electromagnetics and communications have also been used, contributing to an interdisciplinary character of the thesis. Several physical models are derived in the thesis that describes the wireless communications channel and several novel antennas. On the basis of these models, it is investigated how multiple antennas may be employed to increasing the capacity of future wireless communication systems. Furthermore, several aspects of using antenna arrays for finding the directions of arrival of electromagnetic waves, with applications in radar and acoustic sonar, are studied. An often neglected issue when employing several antennas is that the elements affect each other through mutual coupling. By deriving expressions for the mutual coupling, the achievable direction finding performance is analyzed for this case. It is found that if the coupling is known, the effects on direction finding are small and can even increase performance in some cases. Similar results are also obtained when examining the capacity of communication systems employing multiple closely spaced antennas at both the transmitter and receiver. To evaluate the performance of communication systems, a spatio-temporal channel model is proposed that is based on electromagnetic scattering and fundamental physics. By using a dyad notation and concepts from rough surface scattering, a compact formulation of the channel model is obtained. System models are then derived that employs multiple antennas at both the transmitter and receive, so called Multi-Input Multi-Output (MIMO) systems. The polarization properties of the channel as well as those of the antennas are also included in the model, allowing for studies of different antenna arrangements. Two novel antenna solutions are proposed that can be used as diversity receivers in MIMO systems or when performing hi
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