One of the challenges confronting structural engineers in structural control is to find more efficient control algorithms to ensure better and more reliable control results to protect structures against the damaging e...
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One of the challenges confronting structural engineers in structural control is to find more efficient control algorithms to ensure better and more reliable control results to protect structures against the damaging effects of destructive environmental forces. In this paper, a simple control algorithm, namely the Predictive Instantaneous Optimal Control (PIOC) algorithm, is proposed by introducing a new state space form. Different from the classical ground acceleration-based control algorithms, this new control algorithm uses earthquake ground velocity as the input. Since the earthquake ground velocity is not at high frequency as compared with the ground acceleration, it can be predicted at certain time steps beforehand in real-time domain with higher accuracy. This ensures the synchronous execution of the proposed PIOC algorithm with real-time application of the control force. To capture the damaging effects during earthquake ground motions, the force analogy method is used to characterize structures responding in the inelastic domain. Numerical studies are performed to compare the structural response with and without control using both single degree of freedom and multi-degree of freedom structural models. Results show that the PIOC algorithm is effective in reducing the structural response under earthquake excitation. Copyright (C) 2006 John Wiley & Sons, Ltd.
The applicability of term rewriting to program transformation is limited by the lack of control over rule application and by the context-free nature of rewrite rules. The first problem is addressed by languages suppor...
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The applicability of term rewriting to program transformation is limited by the lack of control over rule application and by the context-free nature of rewrite rules. The first problem is addressed by languages supporting user-definable rewriting strategies. The second problem is addressed by the extension of rewriting strategies with scoped dynamic rewrite rules. Dynamic rules are defined at run-time and can access variables available from their definition context. Rules defined within a rule :,cope are automatically retracted at the end of that scope. In this paper, we explore the design space of dynamic rules, and their application to transformation problems. The technique is formally defined by extending the operational semantics underlying the program transformation language Stratego, and illustrated by means of several program transformations in Stratego, including constant propagation, bound variable renaming, dead code elimination, function inlining, and function specialization.
For the difficult task of finding global minimum energy structures for molecular clusters of nontrivial size, we present a highly efficient parallel implementation of an evolutionary algorithm. By completely abandonin...
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For the difficult task of finding global minimum energy structures for molecular clusters of nontrivial size, we present a highly efficient parallel implementation of an evolutionary algorithm. By completely abandoning the traditional concept of generations and by replacing it with a less rigid pool concept, we have managed to eliminate serial bottlenecks completely and can operate the algorithm efficiently on an arbitrary number of parallel processes. Nevertheless, our new algorithm still realizes all of the main features of our old, successful implementation. First tests of the new algorithm are shown for the highly demanding problem of water clusters modeled by a potential with flexible, polarizable monomers (TTM2-F). For this problem, our new algorithm not only reproduces all of the global minima proposed previously in considerably less CPU time but also leads to improved proposals in several cases. These, in turn, qualitatively change our earlier predictions concerning the transitions from all-surface structures to cages with a single interior molecule, and from one to two interior molecules. Furthermore, we compare preliminary results up to n = 105 with locally optimized cuts from several ice modifications. This comparison indicates that relaxed ice structures may start to be competitive already at cluster sizes above n = 90.
The results of 12 well-known and three fault-primitive-based memory test algorithms applied to 0.13 micron technology 512 kB single-port SRAMs are presented. Each test algorithm is used with up to 16 different stress ...
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The results of 12 well-known and three fault-primitive-based memory test algorithms applied to 0.13 micron technology 512 kB single-port SRAMs are presented. Each test algorithm is used with up to 16 different stress combinations (SCs) (i.e. different address sequences, data backgrounds and voltages) resulting in 122 tests. The results show that SCs influence the fault coverage (FC) of the test algorithms, that the highest FC is obtained at a low voltage level and that the highest detected number of unique faults is obtained at a high voltage level. They also show that the tests with the most promising FC, based on the theory, also tend to have the highest FC in practice. Moreover, the test results show that some algorithms detect faults that cannot be explained with the existing fault models, indicating that the existing fault models still leave much to be explained;for example, no theoretical basis exists to model the stresses and the predicted FC for a given test.
Integrated power control algorithms with advanced receivers like adaptive antenna arrays and multiuser detectors have significantly better performance than conventional power control algorithms with matched filters. H...
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Integrated power control algorithms with advanced receivers like adaptive antenna arrays and multiuser detectors have significantly better performance than conventional power control algorithms with matched filters. However, these algorithms are very complex for practical implementation and their significant performance gains were only shown in idealised conditions. In this paper, we study the performance of integrated power control and advanced receivers algorithms for WCDMA uplink that are modified to be more suitable for practical implementation. We simultaneously take into account system imperfections, such as limited bandwidth for power control command, power control command errors, update rate of power control command, delay of power control command, fast fading effects, soft handover, limitation of mobile user minimum and maximum power, etc. Impact of mobile user velocities and errors in filter coefficients determination on performance of the algorithms are also shown. We show that also in this environment, power control algorithms integrated with advanced receivers significantly outperform conventional power control algorithm. Copyright (C) 2006 AEIT.
Tabucol is a tabu search algorithm that tries to determine whether the vertices of a given graph can be colored with a fixed number k of colors such that no edge has both endpoints with the same color. This algorithm ...
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Tabucol is a tabu search algorithm that tries to determine whether the vertices of a given graph can be colored with a fixed number k of colors such that no edge has both endpoints with the same color. This algorithm was proposed in 1987, one year after Fred Glover's article that launched tabu search. While more performing local search algorithms have now been proposed, Tabucol remains very popular and is often chosen as a subroutine in hybrid algorithms that combine a local search with a population based method. In order to explain this unfailing success, we make a thorough survey of local search techniques for graph coloring problems, and we point out the main differences between all these techniques. (c) 2005 Elsevier Ltd. All rights reserved.
Recent new media concerts feature a trend toward the fuller integration ofmodalities enabled by close audiovisual collaborations, avoiding the sometimes artificial separationof disc jockey (DJ) and video jockey (VJ), ...
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Recent new media concerts feature a trend toward the fuller integration ofmodalities enabled by close audiovisual collaborations, avoiding the sometimes artificial separationof disc jockey (DJ) and video jockey (VJ), of audio and visual artist. Integrating audio and visualdomains has been an artistic concern from the experimental films of such notaries as OskarFischinger and Norman McClaren earlier in the 20th century, through 1960s happenings, 1970s analogvideo synthesizers, and 1980s pop videos, to the current proliferation of VJing, DVD labels, andlive cinema (Lew 2004). The rise of the VJ has been allied with the growth in club culture since the1980s, with Super-8 film and video projectionists at early raves now replaced by ''laptopists'' armedwith commercial digital VJ software like Isadora, Aestesis, Motion Dive, and Arkaos VJ.
The paper presents a cascade generalized predictive controller. The cascade control task is performed by one predictive controller and the cascade feature is incorporated in a special predictor. Simulation results are...
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The paper presents a cascade generalized predictive controller. The cascade control task is performed by one predictive controller and the cascade feature is incorporated in a special predictor. Simulation results are presented comparing the performances of the proposed control algorithm to traditional cascade loops including two PI or two GPC controllers. The paper investigates the effects of noise filter on the robustness of the control loops in the cascade control structure. It shows, that with the proposed predictor it is possible to adjust independently the robustness of the inner and outer loops, meanwhile in the traditional cascade loop there are cross effects in this sense. Finally a real time application of the proposed algorithm is presented: the cascade GPC was tested in the oxygen control loop of an experimental fluidized bed boiler.
Redundant call elimination has been an important program optimisation process as it can produce super-linear speedup in optimised programs. In this paper, we investigate use of the tupling transformation in achieving ...
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Redundant call elimination has been an important program optimisation process as it can produce super-linear speedup in optimised programs. In this paper, we investigate use of the tupling transformation in achieving this optimisation over a first-order functional language. Standard tupling technique, as described in [6], works excellently in a restricted variant of the language;namely, functions with single recursion argument. We provide a semantic understanding of call redundancy, upon which we construct an analysis for handling the tupling of functions with multiple recursion arguments. The analysis provides a means to ensure termination of the tupling transformation. As the analysis is of polynomial complexity, it makes the tupling suitable as a step in compiler optimisation.
Association rules mining is a popular data mining modeling tool. It discovers interesting associations or correlation relationships among a large set of data items, showing attribute values that occur frequently toget...
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Association rules mining is a popular data mining modeling tool. It discovers interesting associations or correlation relationships among a large set of data items, showing attribute values that occur frequently together in a given dataset. Despite their great potential benefit, current association rules modeling tools are far from optimal. This article studies how visualization techniques can be applied to facilitate the association rules modeling process, particularly what visualization elements should be incorporated and how they can be displayed. Original designs for visualization of rules, integration of data and rule visualizations, and visualization of rule derivation process for supporting interactive visual association rules modeling are proposed in this research. Experimental results indicated that, compared to an automatic association rules modeling process, the proposed interactive visual association rules modeling can significantly improve the effectiveness of modeling, enhance understanding of the applied algorithm, and bring users greater safisfaction with the task. The proposed integration of data and rule visualizations can significantly facilitate understanding rules compared to their nonintegrated counterpart.
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