Routing problem in wireless sensor network (WSN) is challenging because WSN has distributed feature, transmission requirement, data redundancy and energy restriction. The idea of ant colony optimization (ACO) has been...
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Routing problem in wireless sensor network (WSN) is challenging because WSN has distributed feature, transmission requirement, data redundancy and energy restriction. The idea of ant colony optimization (ACO) has been used in design of routing algorithms for WSN. However, ant colony routing algorithms (ACRs) generally have a serious problem of slow routing discovery so far. In this paper, a feedback-enhanced ant colony routing algorithm (FACR) making use of timed-out forward ants and backward broadcasting ants is proposed to accelerate the routing process. This algorithm is simulated on NS2 and is compared to traditional ant colony routing algorithm (TACR). The results indicate that FACR achieves lower packet loss rate than TACR under the same experimental conditions. Moreover, FACR shows a shorter end to end delay and higher residual energy rate.
Continuous wavelet transform (CWT) is used in this paper for steady-state visual evoked potential (SSVEP) detection in a brain-computer interface (BCI) system. The developed BCI system is designed for the remote contr...
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Continuous wavelet transform (CWT) is used in this paper for steady-state visual evoked potential (SSVEP) detection in a brain-computer interface (BCI) system. The developed BCI system is designed for the remote control of humanoid robot through wireless sensor networks (WSN). A new CWT-based feature extraction method is presented and the whole framework of the BCI system is described. We investigated the feature extraction perfomance for different kinds of mother wavelets. Performance comparison was also conducted between CWT and fast Fourier transform (FFT). The experimental results show that the CWT-based method outperforms the FFT-based one in the SSVEP feature extraction scheme, specifically for short EEG segments. Moreover, the complex Morlet wavelet has significant superiority over several other mother wavelets in the CWT-based SSVEP feature extraction.
This paper deals with the performance improvement of force feedback in bilateral teleoperation with PD controller. In traditional PD structures, the force feedback is simply determined by the position and velocity of ...
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This paper deals with the performance improvement of force feedback in bilateral teleoperation with PD controller. In traditional PD structures, the force feedback is simply determined by the position and velocity of the master and the slave manipulators, which may induce large resistance forces to the operator even in free motion. In this paper, a novel PD bilateral controller is proposed to tackle this problem. By incorporating a distance variable in the controller, we show that the appropriate force feedback can be obtained which still guarantees the system stability. To validate the proposed algorithm, an experiment is also carried out on our single degree of freedom teleoperation system. The results indicate that this strategy is effective for safe teleoperation missions.
As online community question answering (cQA) portals like Yahoo! Answers and Baidu Zhidao have attracted over hundreds of millions of questions, how to utilize these questions and accordant answers becomes increasingl...
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As online community question answering (cQA) portals like Yahoo! Answers and Baidu Zhidao have attracted over hundreds of millions of questions, how to utilize these questions and accordant answers becomes increasingly important for cQA websites. Prior approaches focus on using information retrieval techniques to provide a ranked list of questions based on their similarities to the query. Due to the high variance of question quality and answer quality, users have to spend lots of time on finding the truly best answers from retrieved results. In this paper, we develop an answer retrieval and summarization system which directly provides an accurate and comprehensive answer summary instead of a list of similar questions to user's query. To fully explore the information of relations between queries and questions, between questions and answers, and between answers and sentences, we propose a new probabilistic scoring model to distinguish high-quality answers from low-quality answers. By fully exploiting these relations, we summarize answers using a maximum coverage model. Experiment results on the data extracted from Chinese cQA websites demonstrate the efficacy of our proposed method.
Sparse representation based classification algorithm has been used to solve the problem of human face recognition. The image database is confined to human frontal faces with only illumination and slight expression cha...
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Sparse representation based classification algorithm has been used to solve the problem of human face recognition. The image database is confined to human frontal faces with only illumination and slight expression changes. Cropping and normalization of the face need to be done in advance. In this paper, we apply the sparse representation based algorithm to the problem of general image classification, with a certain degree of intra-class variations and background clutter. Experiments have been done with the sparse representation based algorithm and SVM classifiers on 25 object categories selected from Caltech101 dataset. Experimental results show that without the time-consuming parameter optimization, the sparse representation based algorithm achieves comparable performance with SVM. We argue that the sparse representation based algorithm can also be applied to general image classification task when appropriate image feature is used.
We propose the Tag Allocation Model (TAM) to model social annotation data. TAM is a probabilistic generative model, its key feature is finding the latent reason for each tag. A latent reason can be any discrete featur...
We propose the Tag Allocation Model (TAM) to model social annotation data. TAM is a probabilistic generative model, its key feature is finding the latent reason for each tag. A latent reason can be any discrete features of the document (such as words) or a global noise variable. Inferring the reason for each tag helps TAM reduce the ambiguity of a document with multiple tags. By introducing noise as a reason, TAM can handle noise tags naturally. We perform experiments on three real world data sets. The results show that TAM outperforms state-of-the-art approaches in both held-out perplexity and tag recommendation accuracy.
Network services based on distributed components, which provide advanced network services with lower cost by assigning and reusing useful components running on remote nodes, are attracting increasing attention. In thi...
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ISBN:
(纸本)9781424453665
Network services based on distributed components, which provide advanced network services with lower cost by assigning and reusing useful components running on remote nodes, are attracting increasing attention. In this service, when a component fails, a component that has the same function running on another node can be substituted for it. On the other hand, there are three kinds of failures in network services; a software failure at a component, a hardware failure at a node, and a failure of the physical network. We propose a new method to identify a failure in network services, which determines not only a failure at the application level but also in the network layer by collecting a small number of messages via multiple overlay networks.
Cognitive science is widely studied as a high degree of cross-disciplinary. Various models are presented by several popular architectures. ACT-R (Adaptive Control of Thought-Rational) architecture is one of most popul...
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Cognitive science is widely studied as a high degree of cross-disciplinary. Various models are presented by several popular architectures. ACT-R (Adaptive Control of Thought-Rational) architecture is one of most popular cognitive architectures. A new combination of cognitive science and artificial intelligence is studied in this paper. Signal serials in visual modules are usually artificial defined in many cognitive models, including driver cognitive models. Vision based automatic navigation is explored for visual module of driver cognitive model. Signal serials in visual modules are provided by automatic vision based navigation systems from real driving video, and used for driver model in ACT-R architecture. Results are compared. Experimental result shows that the applying of vision navigation on cognitive model in ACT-R architecture is reliable.
Discovering common shape contour is a promising topic. However, local position and scale variance always leads to the mismatch of similar contours. In this study, we propose Shift Invariant Sparse Coding HMAX (SISCHMA...
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Discovering common shape contour is a promising topic. However, local position and scale variance always leads to the mismatch of similar contours. In this study, we propose Shift Invariant Sparse Coding HMAX (SISCHMAX)to address this problem. Shift Invariant Sparse Coding is used to learn the configuration of line responses on the output of HMAX C1 layer. And we test the proposed method on Caltech101 dataset for discovering object contour. Due to the tolerance of local shift of the lines, sparse coding extracts better object contours using HMAX C1 outputs instead of gray value.
The stability of a force-reflecting bilateral teleoperator in the presence of time delay is solved in the former researches, and recently the four-channel architecture in teleoperation is focused by many literatures. ...
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The stability of a force-reflecting bilateral teleoperator in the presence of time delay is solved in the former researches, and recently the four-channel architecture in teleoperation is focused by many literatures. This paper proposes a novel passive four-channel architecture (PFCA). Furthermore, two types of multilateral shared control architecture existed in space teleoperation are put forward, one is Dual-Master Multilateral Shared Control Architecture (DMMSCA), the other is Dual-Slave Multilateral Shared Control Architecture (DSMSCA). Simulations show that PFCA, DMMSCA and DSMSCA can maintain stability in the presence of large time delay.
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