In this paper, vertically aligned carbon nanotubes field emission devices were fabricated from the as grown carbon nanotubes (CNTs) by furnace thermal CVD at atmospheric pressure. The device was tested in vacuum (/spl...
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In this paper, vertically aligned carbon nanotubes field emission devices were fabricated from the as grown carbon nanotubes (CNTs) by furnace thermal CVD at atmospheric pressure. The device was tested in vacuum (/spl sim/10/sup -6/ torr) for field emission characterization. The turn-on field was about 3 V//spl mu/m, which is comparable to data reported elsewhere.
Separating speech from acoustic interference is a very challenging task. In particular, no system successfully addresses the separation of unvoiced speech. Fricatives and affricates are two main categories of consonan...
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ISBN:
(纸本)0780388747
Separating speech from acoustic interference is a very challenging task. In particular, no system successfully addresses the separation of unvoiced speech. Fricatives and affricates are two main categories of consonants that contain a significant amount of unvoiced signal. We propose a novel system that separates fricatives and affricates from non-speech interference. The system first decomposes the input mixture into segments, each of which contains signal mainly from one source. Then it detects segments dominated by unvoiced portions of fricatives and affricates with a feature-based Bayesian classifier, and groups these segments with voiced speech separated by a previous system. The proposed system is evaluated with various types of interference and produces promising results.
Impairment of hand function is prevalent among stroke survivors, motivating the search for effective rehabilitation therapy. Recent studies have suggested that for upper extremity functional recovery, repetitive train...
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It is known that one of the most disastrous forms of collective human behavior is the kind of crowd stampede induced by panic. This situation often leads to fatalities as people are crushed or trampled. This problem h...
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It is known that one of the most disastrous forms of collective human behavior is the kind of crowd stampede induced by panic. This situation often leads to fatalities as people are crushed or trampled. This problem has been well researched from a socio-psychological point of view. In this paper we attempt to study and analyze the crowd behavior by using an ant colony optimization (ACO) based computational framework. The initial simulations refer to a panic situation generated in a few connected cities of a war affected country.
Microkernel based systems tend to depend heavily on IPC. This paper addresses the problem of a system response spanning more than one task in an embedded real-time system. The approach is based on a mix of classical r...
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Microkernel based systems tend to depend heavily on IPC. This paper addresses the problem of a system response spanning more than one task in an embedded real-time system. The approach is based on a mix of classical response time analysis equations and a graph based approach to estimate the impact of different parts of the system on the time needed by the system to respond. This approach has the major advantage of being intuitive.
In nuclear power plants, there is an accelerating trend to upgrade and replace analog instrumentation and control systems with digital systems. This transition from analog to digital I&C systems is due to their ad...
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ISBN:
(纸本)089448690X
In nuclear power plants, there is an accelerating trend to upgrade and replace analog instrumentation and control systems with digital systems. This transition from analog to digital I&C systems is due to their added capabilities and their potential to improve reliability and safety of the corresponding plants. As this replacement process continues, one or more methodologies to address digital I&C system reliability are needed to quantify the risk introduced into the plants by such systems. In reviewing the proposed methodologies, it has become apparent that there is no benchmark system available to be used as the basis for methodology comparison. A set of preliminary requirements for a benchmark system is presented to evaluate objectively methodologies available for the reliability modeling of digital I&C systems in nuclear power plants. These requirements will provide a basis for the future development of a benchmark system.
This paper explores feedback controller design for cavity flows based on reduced-order models derived using Proper Orthogonal Decomposition (POD) along with Galerkin projection method. Our preliminary analysis shows t...
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This paper explores feedback controller design for cavity flows based on reduced-order models derived using Proper Orthogonal Decomposition (POD) along with Galerkin projection method. Our preliminary analysis shows that the equilibrium of the POD model is unstable and a static output feedback controller cannot stabilize it. We develop Linear Quadratic (LQ) optimal state feedback controllers and LQ optimal observers for the linearized models. The linear controllers and observers are applied to the nonlinear system using simulations. The controller robustness is numerically tested with respect to different POD models generated at different forcing frequencies. An estimation for the region of attraction of the linear controllers is also provided.
Most edge detection algorithms include three main stages: smoothing, differentiation, and labeling. In this paper, we evaluate the performance of algorithms in which competitive learning is applied first to enhance ed...
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Most edge detection algorithms include three main stages: smoothing, differentiation, and labeling. In this paper, we evaluate the performance of algorithms in which competitive learning is applied first to enhance edges, followed by an edge detector to locate the edges. In this way, more detailed and relatively more unbroken edges can be found as compared to the results when an edge detector is applied alone. The algorithms compared are K-Means, SOM and SOGR for clustering, and Canny and GED for edge detection. Perceptionally, best results were obtained with the GED-SOGR algorithm. The SOGR is also considerably simpler and faster than the SOM algorithm.
Although wireless hearing aid systems have been proposed by several research groups, no viable whole-system simulation results have been reported so far for better evaluation of this advanced hearing device. In this p...
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Although wireless hearing aid systems have been proposed by several research groups, no viable whole-system simulation results have been reported so far for better evaluation of this advanced hearing device. In this paper, a system-level simulation using ADStrade is presented based on one of the typical wireless hearing aid architecture. The results show that the wireless hearing aid system function can be simulated and verified. And from these results, we can get a very promising performance which can be used for further design
作者:
Kicinger, RafalArciszewski, TomaszDe Jong, KennethCivil
Environmental and Infrastructure Engineering Department Critical Infrastructure Protection Program George Mason University 4400 University Drive Fairfax VA 22030 Civil
Environmental and Infrastructure Engineering Department George Mason University MS 4A6 4400 University Drive Fairfax VA 22030 Computer Science Department
George Mason University MS 4A5 4400 University Drive Fairfax VA 22030
This paper proposes a new approach to representing structural system inspired by various models of complex systems. Several types of generative representations of steel structural systems are provided and empirically ...
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ISBN:
(纸本)0784407940
This paper proposes a new approach to representing structural system inspired by various models of complex systems. Several types of generative representations of steel structural systems are provided and empirically investigated. These representations utilize various kinds of cellular automata to generate design concepts of steel structures in tall buildings. In the paper, a brief overview of the state-of-the-art in cellular automata and generative design is presented. Next, several types of generative representations of steel structural systems in tall buildings are described. The paper also reports the results of several design experiments. They have shown that generative representations produce novel structural shaping patterns which are qualitatively different than the patterns obtained using traditionally used parameterized representations. They also significantly improve the performance of evolutionary algorithms optimizing the structural systems. Finally, research conclusions are presented and most promising paths of future research are discussed.
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