Domain knowledge is crucial for effective performance in autonomous control systems. Typically, human effort is required to encode this knowledge into a control algorithm. In this paper, we present an approach to lang...
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Domain knowledge is crucial for effective performance in autonomous control systems. Typically, human effort is required to encode this knowledge into a control algorithm. In this paper, we present an approach to language grounding which automatically interprets text in the context of a complex control application, such as a game, and uses domain knowledge extracted from the text to improve control performance. Both text analysis and control strategies are learned jointly using only a feedback signal inherent to the application. To effectively leverage textual information, our method automatically extracts the text segment most relevant to the current game state, and labels it with a task-centric predicate structure. This labeled text is then used to bias an action selection policy for the game, guiding it towards promising regions of the action space. We encode our model for text analysis and game playing in a multi-layer neural network, representing linguistic decisions via latent variables in the hidden layers, and game action quality via the output layer. Operating within the Monte-Carlo Search framework, we estimate model parameters using feedback from simulated games. We apply our approach to the complex strategy game Civilization II using the official game manual as the text guide. Our results show that a linguistically-informed game-playing agent significantly outperforms its language-unaware counterpart, yielding a 34% absolute improvement and winning over 65% of games when playing against the built-in AI of Civilization.
We provide an algorithm for computing the centered Hausdorff measures of self-similar sets satisfying the strong separation condition. We prove the convergence of the algorithm and test its utility on some examples. (...
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We provide an algorithm for computing the centered Hausdorff measures of self-similar sets satisfying the strong separation condition. We prove the convergence of the algorithm and test its utility on some examples. (C) 2011 Elsevier Ltd. All rights reserved.
A novel precoding-based initial ranging signal is presented for the successive multiuser detection and interference cancellation (SMUD) algorithm in OFDMA uplink systems. The ranging codes in the multiple ranging symb...
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A novel precoding-based initial ranging signal is presented for the successive multiuser detection and interference cancellation (SMUD) algorithm in OFDMA uplink systems. The ranging codes in the multiple ranging symbols are coded by the precoding matrix. The performance of the SMUD algorithm is greatly improved by using the decoded signal of the received precoded ranging signal.
Reversible digital watermarking techniques enable the recovery of the original 'cover image' from a watermarked image in a distortion-free way. Reversible watermarking techniques find application in military a...
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Reversible digital watermarking techniques enable the recovery of the original 'cover image' from a watermarked image in a distortion-free way. Reversible watermarking techniques find application in military and medical imagery, where integrity of the cover image is of utmost importance. However, in practice, many military data transmissions occur over communication channels whose noise levels are so high that the receiving system is unable to correct all errors in the received data. In such a case, the authors are bound to get non-zero distortion in the recovered cover image as well as the extracted watermark, in spite of using reversible watermarking techniques. In this study, they investigate the effect of high data error rates on different state-of-the-art reversible watermarking algorithms. Their simulation results help to choose the most suitable reversible watermarking scheme, depending on whether the distortion of the retrieved cover image or the distortion of the retrieved watermark is the primary concern.
This paper considers two additional factors of the widely researched vehicle routing problem with time windows (VRPTW). The two factors, which are very common characteristics in realworld, are uncertain number of vehi...
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This paper considers two additional factors of the widely researched vehicle routing problem with time windows (VRPTW). The two factors, which are very common characteristics in realworld, are uncertain number of vehicles and simultaneous delivery and pick-up service. Using minimization of the total transport costs as the objective of the extension VRPTW, a mathematic model is constructed. To solve the problem, an efficient multiswarm cooperative particle swarm optimization (MCPSO) algorithm is applied. And a new encoding method is proposed for the extension VRPTW. Finally, comparing with genetic algorithm (GA) and particle swarm optimization (PSO) algorithm, the MCPSO algorithm performs best for solving this problem.
This paper addresses the design of a sliding mode based extremum-seeking controller for a class of single-input single-output (SISO) uncertain nonlinear systems with unmatched and state-dependent strong nonlinearities...
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This paper addresses the design of a sliding mode based extremum-seeking controller for a class of single-input single-output (SISO) uncertain nonlinear systems with unmatched and state-dependent strong nonlinearities. We demonstrate that it is possible to achieve an arbitrarily small neighborhood of the desired optimal point using only output-feedback. The key idea is the combination of a periodic switching function with a norm state observer. As an important advantage, we show that the proposed scheme achieves extremum-seeking for all initial conditions, i.e., the real-time optimization algorithm has global convergence properties. An application to a simple nonderivative optimizer illustrates the viability of the proposed approach. (C) 2011 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.
Stabilization problem for a linear plant with time delay control is considered. A new method of the sliding mode control design minimizing the effects of system disturbances is presented. It is based on a combination ...
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Stabilization problem for a linear plant with time delay control is considered. A new method of the sliding mode control design minimizing the effects of system disturbances is presented. It is based on a combination of the well-known predictor-based sliding mode control algorithm with the recently developed invariant ellipsoid method. The theoretical results are supported by numerical simulations. (C) 2011 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.
The imaginary part of the complex potential energy surface (CPES) provides the autoionization, Auger and ICD (Intermolecular Coulombic Decay) ionization decay rates as functions of the variations in the molecular elec...
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The imaginary part of the complex potential energy surface (CPES) provides the autoionization, Auger and ICD (Intermolecular Coulombic Decay) ionization decay rates as functions of the variations in the molecular electronic structure and geometry. We introduce here a novel approach which enables the calculations the molecular complex potential energy surfaces by the standard computational algorithms which were originally developed for calculating real PES of stable molecules. As an illustrative numerical example we have calculated the CPES for the molecular autoionization of hydrogen molecule, H-2[(1)Sigma(+)(g)] where the two electrons are doubly excited. (C) 2011 Elsevier B. V. All rights reserved.
Online power system stability assessment during restoration has not been strongly addressed yet. The introduction of wide area measurement systems (WAMS), however, made it possible to monitor the stability online. Thi...
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Online power system stability assessment during restoration has not been strongly addressed yet. The introduction of wide area measurement systems (WAMS), however, made it possible to monitor the stability online. This study technically presents a detailed analysis of stability during restoration using WAMS. The power system build-up strategy is used as the restoration approach, based on which the early and the last stages of restoration are to divide the power system into islands and interconnect them, respectively. In fact, the practical use of WAMS at the early stages of restoration provides precise determination of generators loading steps. Moreover, unification of phase angle references at different islands and presentation of tie line energising priority list are significant benefits of WAMS at the last stages of restoration. The New England 39-bus power system is used to demonstrate the proposed algorithm and verify the results. The proposed method is also applied on the IEEE 118-bus system as a large-scale power system to prove its capability in practical systems.
Longitudinal performance and reliability of microelectronic structures is strongly influenced by the condition of interconnects. Degradation processes invoke changes, progressive in time, on the surface, in the body o...
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Longitudinal performance and reliability of microelectronic structures is strongly influenced by the condition of interconnects. Degradation processes invoke changes, progressive in time, on the surface, in the body of interconnect layer, in the boundary between interconnect and the Si/SiO2 substrate, and in the area of substrate near Al line. Geometrical scale of these changes may vary in wide range, reaching nanometers. The authors investigate the condition of Al path of a fatigued commercial electronic circuit (memory), using in-house developed scanning thermal microscope (SThM) and commercial high resolution X-ray diffractometer (XRD). Series of SThM images were obtained for varying temperature of Wollaston probe working in active mode. The images, after processing by 2-dimensional spatial FFT, reveal various ingredients of the surface and internal structure of the Al line. FFT power spectrum dispersion is proposed as a measure of the amount of information available from the scan image. This measure may be used to determine the most efficient temperature of Wollaston probe. The result is a preliminary analysis of feasibility of the SThM approach for characterization of degradation process. In general SThM shall be perceived as a new technique for reliability analysis. (C) 2011 Elsevier Ltd. All rights reserved.
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