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991.
Ziyou Xiong 《Pattern Analysis & Applications》2005,8(1-2):62-71
We present our studies on the application of Coupled Hidden Markov Models(CHMMs) to sports highlights extraction from broadcast video using both audio and video information. First, we generate audio labels using audio classification via Gaussian mixture models, and video labels using quantization of the average motion vector magnitudes. Then, we model sports highlights using discrete-observations CHMMs on audio and video labels classified from a large training set of broadcast sports highlights. Our experimental results on unseen golf and soccer content show that CHMMs outperform Hidden Markov Models(HMMs) trained on audio-only or video-only observations. Next, we study how the coupling between the two single-modality HMMs offers improvement on modelling capability by making refinements on the states of the models. We also show that the number of states optimized in this fashion also gives better classification results than other number of states. We conclude that CHMMs provide a promising tool for information fusion techniques in the sports domain for audio-visual event detection and analysis. 相似文献
992.
In this paper, a new identification method performed in the time domain based on the decentralized step‐test is proposed for two inputs and two outputs (TITO) processes with significant interactions. In terms of parameter identification, the coupled closed‐loop TITO system is decoupled to obtain four individual single open‐loop systems with the same input signal. As in the SISO case, new linear regression equations are derived, from which the parameters of a first‐ or second‐order plus dead‐time model can be obtained directly. The proposed method outperforms the existing estimation methods for multivariable control systems that use step‐test responses. Furthermore, the method is robust in the presence of high levels of measurement noise. Simulation examples are given to show both effectiveness and practicality of the identification method for a wide range of multivariable processes. The usefulness of the identified method in multivariable process modeling and controller design is demonstrated. 相似文献
993.
This paper presents a new scheme of face image feature extraction, namely, the two-dimensional Fisher linear discriminant. Experiments on the ORL and the UMIST face databases show that the new scheme outperforms the PCA and the conventional PCA+FLD schemes, not only in its computational efficiency, but also in its performance for the task of face recognition. 相似文献
994.
Zhixin Liu Cheng S. Liveris A.D. Zixiang Xiong 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2006,52(10):4358-4379
Nested lattice quantization provides a practical scheme for Wyner-Ziv coding. This paper examines the high-rate performance of nested lattice quantizers and gives the theoretical performance for general continuous sources. In the quadratic Gaussian case, as the rate increases, we observe an increasing gap between the performance of finite-dimensional nested lattice quantizers and the Wyner-Ziv distortion-rate function. We argue that this is because the boundary gain decreases as the rate of the nested lattice quantizers increases. To increase the boundary gain and ultimately boost the overall performance, a new practical Wyner-Ziv coding scheme called Slepian-Wolf coded nested lattice quantization (SWC-NQ) is proposed, where Slepian-Wolf coding is applied to the quantization indices of the source for the purpose of compression with side information at the decoder. Theoretical analysis shows that for the quadratic Gaussian case and at high rate, SWC-NQ performs the same as conventional entropy-coded lattice quantization with the side information available at both the encoder and the decoder. Furthermore, a nonlinear minimum mean-square error (MSE) estimator is introduced at the decoder, which is theoretically proven to degenerate to the linear minimum MSE estimator at high rate and experimentally shown to outperform the linear estimator at low rate. Practical designs of one- and two-dimensional nested lattice quantizers together with multilevel low-density parity-check (LDPC) codes for Slepian-Wolf coding give performance close to the theoretical limits of SWC-NQ 相似文献
995.
On the complexity of and algorithms for finding the shortest path with a disjoint counterpart 总被引:4,自引:0,他引:4
Dahai Xu Yang Chen Yizhi Xiong Chunming Qiao Xin He 《Networking, IEEE/ACM Transactions on》2006,14(1):147-158
Finding a disjoint path pair is an important component in survivable networks. Since the traffic is carried on the active (working) path most of the time, it is useful to find a disjoint path pair such that the length of the shorter path (to be used as the active path) is minimized. In this paper, we first address such a Min-Min problem. We prove that this problem is NP-complete in either single link cost (e.g., dedicated backup bandwidth) or dual link cost (e.g., shared backup bandwidth) networks. In addition, it is NP-hard to obtain a K-approximation to the optimal solution for any K>1. Our proof is extended to another open question regarding the computational complexity of a restricted version of the Min-Sum problem in an undirected network with ordered dual cost links (called the MSOD problem). To solve the Min-Min problem efficiently, we introduce a novel concept called conflicting link set which provides insights into the so-called trap problem, and develop a divide-and-conquer strategy. The result is an effective heuristic for the Min-Min problem called COnflicting Link Exclusion (COLE), which can outperform other approaches in terms of both the optimality and running time. We also apply COLE to the MSOD problem to efficiently provide shared path protection and conduct comprehensive performance evaluation as well as comparison of various schemes for shared path protection. We show that COLE not only processes connection requests much faster than existing integer linear programming (ILP)-based approaches but also achieves a good balance among the active path length, bandwidth efficiency, and recovery time. 相似文献
996.
Colinge J.-P. Floyd L. Quinn A.J. Redmond G. Alderman J.C. Xiong W. Cleavelin C.R. Schulz T. Schruefer K. Knoblinger G. Patruno P. 《Electron Device Letters, IEEE》2006,27(3):172-174
Trigate silicon-on-insulator (SOI) MOSFETs have been measured in the 5-400 K temperature range. The device fin width and height is 45 and 82 nm, respectively, and the p-type doping concentration in the channel is 6/spl times/10/sup 17/ cm/sup -3/. The subthreshold slope varies linearly with temperature as predicted by fully depleted SOI MOS theory. The mobility is phonon limited for temperatures larger than 100 K, while it is limited by surface roughness below that temperature. The corner effect, in which the device corners have a lower threshold voltage than the top and sidewall Si/SiO/sub 2/ interfaces, shows up at temperatures lower than 150 K. 相似文献
997.
建筑生态环境评价体系及评价标准的分析与探讨 总被引:1,自引:1,他引:1
提出了建筑生态环境评价的概念和建立建筑生态环境评价体系的意义,指出了其评价原则、内容和方法.对国外建筑生态环境的评价标准做了详细介绍和对比分析,能指导我国建立适合我国国情的绿色生态建筑的评估体系,创造出更好的建筑生态环境. 相似文献
998.
基于对Web系统的特点研究,提出了一个全面测试Web系统的框架.并基于模型驱动的软件测试思想(MDT),重点研究了此框架中的中间业务逻辑层的测试建模方法:定义了一个平台相关的测试模型(硎)——EJB构件测试模型;并给出了对它的模型复原算法和模型一致性检测方法.该测试建模方法,从软件构件的层次,实现了EJB静态结构和动态行为的建模,并通过模型一致性检测实现EJB代码的潜在缺陷检查.这一测试模型将为测试用例和测试数据的生成提供有力的支持. 相似文献
999.
在分析了火电厂燃料桥式抓斗(行车)运行特性基础上。采用变频控制技术对原有控制系统进行了改造,优化了控制系统。解决了调速范围小、速度稳定性差、无法长时间低速下吊重物、故障率高等缺点。 相似文献
1000.