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221.
Xinguo Yu Liyuan Li Hon Wai Leong 《Journal of Visual Communication and Image Representation》2009,20(2):117-130
This paper presents a system for providing interactive broadcast services for live soccer video that is based on instant semantics acquisition. Currently, we have implemented two such interactive services: live event alert and on-the-fly language selection. The live event alert service has a small time lag of about 30 s for a short video clip to reach its final viewer and at most 1.5 min for a long clip of the live event. The on-the-fly language selection service allows users to choose their preferred contents and preferred language. The motivation for this work is that such interactive services will greatly increase the value of live soccer video. Currently, similar systems attempt to derive semantics of a soccer game from gamelog in freestyle text format and low-level features of the video, which is a challenging task. In this paper, we tackle this challenge with a combination of both gamelog input tool and targeted algorithm proposed in this paper. Our system is powered by our proposed semantic gamelog input tool that facilitates fast and accurate input of a semantic gamelog that contains basic semantic information of atomic events. When an interesting event occurs, our system performs boundary detection of these events by combining features extracted from the video with additional information from the semantic gamelog. This additional information facilitates our system to achieve accurate and very fast boundary detection of these events to support our live event alert service. Our system also implements a gamelog translation machine which translates the semantic gamelog (encoded in a game-specific code) into any natural language, provided that there is a configuration file for that language. Combining our gamelog translation machine with existing text-to-speech technology, we provide the on-the-fly language selection service. (Currently, our system supports English, Chinese, and Malay.) 相似文献
222.
随着工艺的进步,△∑A/D只适用于低速高精度领域的观念正在被打破。本论文设计一个单环二阶前馈反馈混合型多比特△∑调制器,用于ADSL。为了能让PH2相向PH1相借用12%的时间,以降低对运放、比较器和DEM单元速度的要求,本论文改进了传统的不交叠时钟产生电路。为解决无源加法器时钟馈通对比较结果的影响,调整了比较器和加法器的时序。
本设计采用1.8V电源电压,UMC 0.18um CMOS工艺。芯片测试结果显示:在80MHz时钟频率,32倍过采样下,调制器达到了79dB动态范围,71.3dB SNDR,11mW功耗和1.47pJ/step的FOM值。 相似文献
223.
224.
Nonlinear Dynamics - A modified corticothalamic (MCT) system with multiple delays for epileptic absence seizures is taken as a study object. Synchronization transition dynamics of two time-delay... 相似文献
225.
Liu Bin An Chongwei Geng Xiaoheng Yang Liyuan Xu Shuai Ye Baoyun Xu Ruixuan Wang Jingyu 《Journal of Thermal Analysis and Calorimetry》2019,135(6):3303-3309
Journal of Thermal Analysis and Calorimetry - 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) has drawn extensive attention because of its heat resistance and insensitivity properties. In this... 相似文献
226.
Perovskite solar cells(PSCs) have attracted much attention because of their high efficiencies and low costs for production.Although academic research started late in China, compared to that in Europe and Korea, the majority of active PSC research is now conducted in China; furthermore, Chinese research groups currently hold the certified highest efficiency record for both an individual PSC and a PSC module. China is also the world's largest supplier of solar modules, making it a promising country in which to realize the commercialization of PSCs. Herein, we review PSC research activities undertaken in China(both academic and industrial) and discuss significant remaining challenges to overcome for early commercialization of PSCs. We propose that research activities shift away from material and device structure development toward improving PSC stability and developing methods for large-area module fabrication. In addition, we suggest that a recognized certification center is urgently needed in China to further accelerate PSC research. 相似文献
227.
Zhaorui Li Kristin Werner Kun Qian Rui You Agata Pucienik Aiping Jia Lihui Wu Liyuan Zhang Haibin Pan Helmut Kuhlenbeck Shamil Shaikhutdinov Weixin Huang Hans‐Joachim Freund 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(41):14828-14835
The interaction of hydrogen with reduced ceria (CeO2?x) powders and CeO2?x(111) thin films was studied using several characterization techniques including TEM, XRD, LEED, XPS, RPES, EELS, ESR, and TDS. The results clearly indicate that both in reduced ceria powders as well as in reduced single crystal ceria films hydrogen may form hydroxyls at the surface and hydride species below the surface. The formation of hydrides is clearly linked to the presence of oxygen vacancies and is accompanied by the transfer of an electron from a Ce3+ species to hydrogen, which results in the formation of Ce4+, and thus in oxidation of ceria. 相似文献
228.
Liyuan Wu Qian Wang Chuanghua Yang Ruge Quhe Pengfei Guan Pengfei Lu 《The European Physical Journal B - Condensed Matter and Complex Systems》2018,91(2):46
Different main-group metal atoms embedded in crown oxygen-doping graphene (metal@OG) systems are studied by the density functional theory. The binding energies and electronic structures are calculated by using first-principles calculations. The binding energy of metal@OG system mainly depends on the electronegativity of the metal atom. The lower the value of the electronegativity, the larger the binding energy, indicating the more stable the system. The electronic structure of metal@OG arouses the emergence of bandgap and shift of Dirac point. It is shown that interaction between metal atom and crown oxygen-doping graphene leads to the graphene’s stable n-doping, and the metal@OG systems are stable semiconducting materials, which can be used in technological applications. 相似文献
229.
Liyuan Li Weimin Huang Irene Yu-Hua Gu Qi Tian 《IEEE transactions on image processing》2004,13(11):1459-1472
This paper addresses the problem of background modeling for foreground object detection in complex environments. A Bayesian framework that incorporates spectral, spatial, and temporal features to characterize the background appearance is proposed. Under this framework, the background is represented by the most significant and frequent features, i.e., the principal features, at each pixel. A Bayes decision rule is derived for background and foreground classification based on the statistics of principal features. Principal feature representation for both the static and dynamic background pixels is investigated. A novel learning method is proposed to adapt to both gradual and sudden "once-off" background changes. The convergence of the learning process is analyzed and a formula to select a proper learning rate is derived. Under the proposed framework, a novel algorithm for detecting foreground objects from complex environments is then established. It consists of change detection, change classification, foreground segmentation, and background maintenance. Experiments were conducted on image sequences containing targets of interest in a variety of environments, e.g., offices, public buildings, subway stations, campuses, parking lots, airports, and sidewalks. Good results of foreground detection were obtained. Quantitative evaluation and comparison with the existing method show that the proposed method provides much improved results. 相似文献
230.
Cellulose - During the oil and gas drilling engineering, the selection of drilling fluids must take account of the technical and environmental factors. This study investigated the effectiveness of... 相似文献