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International Conference on Information and communication Technology Convergence (ICTC)

作者： Seungho Lee Junghoon Lee Yongtae Lee Myungsun Baek Bomi Lim Jungkyu Rho Incheol Jeong Jaesang Cha Department of Media Engineering Seoul National University of Science and Technology Seoul South Korea Principal Member of Engineering Staff Broadcasting System Research Department Broadcasting & Telecommunication Media Research Division ETRI South Korea Department of Computer Science. Seokyeong University Seoul South Korea Department of Computer and Communication Engineering Sungkonghoe University Seoul South Korea

This paper compared ACF(Auto Correlation Feature) characteristics for ZCD, Kasami and Golay codes. Sequence codes have been used as a spreading sequence in order to overcome ICI(Inter Code Interference) caused by transmitter and MPI(Multiple Path Interference) in receiver. In this paper, we abstracted characteristics of each spreading code and analyzed the properties of them.

关键词： Correlation Watermarking Density estimation robust algorithm Mathematical model Interference Equations Error analysis

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A no-reference image quality evaluation based on power spectrum

A no-reference image quality evaluation based on power spect...

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3DTV Conference

作者： Yan Zhang Ping An Qiuwen Zhang Liquan Shen Zhaoyang Zhang School of Communication and Information Engineering Shanghai University China Department of Computer Science and Technology Anhui University of Finance and Economics China Key Laboratory of Advanced Displays and System Application Ministry of Education China

ISBN: (纸本)9781612841618

No-reference quality evaluation is more difficult because it does not refer to any image. However, in some cases, like virtual view images, can not find the reference image, no-reference method had to be used. With the free viewpoint video technology development and application, measuring the performance of the multiview video system is essential and virtual view image quality evaluation is one of the key technologies in the system. The characteristic of virtual view image quality evaluation is that most of the virtual view images haven't reference images and can't be assessed using general measures such as PSNR of full-reference. Therefore, this paper proposed a no-reference image quality evaluation method based on image power spectrum. Experimental results show that the proposed method is consistent with PSNR.

关键词： PSNR Image quality Three dimensional displays Transform coding Mathematical model Speckle

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Improved multi-view depth estimation for view synthesis in 3D video coding

Improved multi-view depth estimation for view synthesis in 3...

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3DTV Conference

作者： Qiuwen Zhang Ping An Yan Zhang Liquan Shen Zhaoyang Zhang School of Communication and Information Engineering Shanghai University China Key Laboratory of Advanced Displays and System Application Ministry of Education China Department of Computer Science and Technology Anhui University of Finance and Economics China

ISBN: (纸本)9781612841618

Multi-view depth estimation is an important part in the virtual view synthesis and depth map coding within the 3DV/FTV applications. However, existing depth estimation methods generally have difficulty to generate good depth results around object edges or in areas with less texture. To solve this problem, we propose an improved algorithm to obtain a smooth and accurate depth map for view synthesis in 3D video coding. The proposed method aims to preserve details in the depth map and simultaneously smooth depths in object boundary occluded area, less texture and discontinuity regions, to avoid blurring in the synthesized views. Experimental results show a significant improvement of the initial input depth maps and coding efficiency, as well as a reduction of view synthesis artifacts.

关键词： Estimation Pixel Three dimensional displays Encoding Rendering (computer graphics) Image coding Transform coding

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Efficient rendering distortion estimation for depth map compression

Efficient rendering distortion estimation for depth map comp...

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IEEE International Conference on Image Processing

作者： Qiuwen Zhang Ping An Yan Zhang Zhaoyang Zhang School of Communication and Information Engineering Shanghai University China Key Laboratory of Advanced Displays and System Application Ministry of Education China Department of Computer Science and Technology Anhui University of Finance and Economics China

A depth map represents three-dimensional (3D) scene information and is used to synthesize virtual views in 3D video. Since the quality of synthesized virtual views highly depends on the quality of depth map, efficient depth compression is crucial to realize the 3D video system. However compressing depth map using existing video coding techniques yields unacceptable distortions while rendering virtual views. To solve this problem, we propose an efficient depth map compression method for the view rendering, a novel distortion metric base on view rendering distortions instead of distortion of depth map itself. First, we derive relationships between distortions in coded depth map and rendered view. Then, a region based video characteristics distortion model is proposed for precisely estimation distortion in view synthesis. Finally, experimental results have shown that 1.8 dB coding gain in terms of PSNR and subjective quality improvement of synthesized views are achieved by the proposed method.

关键词： Image coding Rendering (computer graphics) Three dimensional displays Cameras Geometry Encoding Estimation

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An improved depth map estimation for coding and view synthesis

An improved depth map estimation for coding and view synthes...

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IEEE International Conference on Image Processing

Inaccuracy depth estimation may influence on depth coding and virtual view rendering in the free-viewpoint television (FTV) system, an improved depth map estimation is proposed to solve the problem for coding and view synthesis. Firstly, check the consistency of initial depth, and the influence of initial miss-matches is minimized by introduction of an additional adaptive matching error selection that penalizes the unreliable matches. Then according to certain criteria, the multi-reference depth maps are merged into one disparity map to improve the quality of disparity map. Finally, a multilateral filtering is used to preserve details in the depth map and simultaneously smooth the depths in occluded areas at object boundary, less texture and discontinuity regions. Experimental results show a significant improvement of the initial input depth maps and coding efficiency, as well as a reduction of view synthesis artifacts.

关键词： Estimation Image coding Rendering (computer graphics) Transform coding Three dimensional displays Filtering

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Quantum-limited phase-matching effect in a Λ-type laser system

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Physical Review A 2011年第6期83卷 063846-063846页

作者： Deshui Yu Jingbiao Chen Department of Applied Physics The University of Tokyo Bunkyo-ku Tokyo 113-8656 Japan Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication System & Network School of Electronics Engineering & Computer Science Peking University Beijing 100871 P.R. China

The theory of a quantum-limited phase-matching effect in a Λ-type lasing system is studied in detail based on the quantum Langevin approach. Two quasimonochromatic fields are directly generated based on two lasing transitions. We find that the coherence between two lasers can well exceed the linewidth of either laser field. This result denotes that two field phases match each other although either laser field has a high phase fluctuation. Unlike the phase-matching effect based on atomic absorption, the final coherence between two laser fields here is not limited by saturation broadening, and the higher laser intensities lead to a higher coherence. Additionally, based on a linear stability analysis, we find that the instability of the field steady state can substantially restrict the occurrence of this phase-matching effect in the bad-cavity limit for a high pump rate. We also discuss the spectrum of amplitude fluctuations of output fields, and the result shows that the squeezing of amplitude fluctuations at low frequencies for a single field oscillating inside the cavity is damaged in the case of two fields oscillating.

关键词： LASERS LIGHT amplifiers OPTOELECTRONIC devices NONLINEAR optics BASES (Linear topological spaces)

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Using P2P Networks to Repair Packet Losses in Digital Video Broadcasting systems

Using P2P Networks to Repair Packet Losses in Digital Video ...

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International Conference on Parallel and Distributed systems (ICPADS)

作者： Yung-Tsung Weng Ce-Kuen Shieh Tzu-Chi Huang Yu-Ben Miao Department of Management Information System Far East University Tainan Taiwan Institute of Computer and Communication Engineering Department of Electrical Engineering National Cheng Kung University Tainan Taiwan Department of Electric Engineering Lunghwa University of Science and Technology Taoyuan Taiwan Information and Communications Research Laboratories Industrial Technology Research Institute Hsinchu Taiwan

Digital multimedia broadcasting services require resiliency against signal fading due to signal encounters with bad weather, terrain obstructions, such as tree, building, etc. There are several solutions that use peer-to-peer network to repair packet losses. But they have some shortcomings such as long lookup latency, control message overhead, flash crowd problem and low chunk availability. In this paper we propose a novel solution that considers load distribution in structured peer-to-peer networks and repairing packet losses in short lookup latency. Our proposed solution doesn't need to modify the codec technology for multimedia stream. Our proposed solution can achieve load evenly distributed, high chunk availability, short lookup latency and low control message overhead by using peer-to-peer network to repair packet losses in digital multimedia broadcasting systems.

关键词： Peer to peer computing Digital video broadcasting Media Message systems Streaming media Receivers Multimedia communication

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CR Enabled TD-LTE within TV White Space: system Level Performance Analysis

CR Enabled TD-LTE within TV White Space: System Level Perfor...

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2011 IEEE Global Telecommunications Conference - GLOBECOM 2011

作者： Junfeng Xiao Feng Ye Tingjian Tian Rose Qingyang Hu Wireless Research Department of Chengdu Research Institute Huawei Technologies Company Limited Chengdu China Communication System Technology Research Department Huawei Technologies Company Limited Chengdu China Department of Electrical and Computer Engineering Utah State University Logan UT USA

Cognitive Radio has emerged as a new technology to improve spectrum utilization and to alleviate spectrum scarcity by allowing unlicensed users to sense and opportunistically access the under-utilized spectrum. This paper proposes a system framework for the Cognitive Radio enabled TD-LTE system that opportunistically accesses and utilizes the TV White Space spectrum. The system performance of both TV broadcasting network and TD-LTE network is evaluated and analyzed. The simulation studies show that the proposed framework can significantly improve the performance of both TV and TD-LTE systems when they are co-operating within the same TV spectrum with TV as the primary user and TD-LTE as the secondary user. Both TV spectrum utilization and TD-LTE coverage are greatly enhanced.

关键词： TV Sensors Switches Correlation Interference White spaces TV broadcasting

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SEWOS: Bringing Semantics into Web operating system

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International Journal of computer Science Issues 2011年第3 3-1期8卷 515-521页

作者： Riad, A.M. Elminir, Hamdy K. ElSoud, Mohamed Abu Sabbeh, Sahar F. Information system department Faculty of computers and information sciences Mansoura university Egypt Department of Communication Misr Academy for Engineering and technology Faculty of computers and information sciences Mansoura University Egypt Computer Science department Faculty of computers and information sciences Mansoura University Egypt Alzarka Higher institute for administration and computer sciences Damietta Egypt

The revolution in web world led to increasing users' needs, demands and expectations. By the time, those needs developed starting from ordinary static pages, moving on to fully dynamic ones and reaching the need for services and applications to be available on the web!.. Those demands changed the perspective of our web today to what's said to be a cloud of computing that aims mainly to provide applications as services for web user. As time goes by, applications were just not enough;users needed their applications and data available anytime, anywhere. For these reasons, traditional operating system functionality was needed to be provided as a service that integrates several applications together with user's data. In this paper we present the detailed description, implementation and evaluation of SEWOS [1]- a semantically enhanced web operating system- that provides the feel, look and mimic traditional desktop applications using desktop metaphor.

关键词： Semantics

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Cross-cultural study on feasible sound levels of possible warning sounds for quiet vehicles

Cross-cultural study on feasible sound levels of possible wa...

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40th International Congress and Exposition on Noise Control engineering 2011, INTER-NOISE 2011

作者： Yamauchi, Katsuya Menzel, Daniel Fastl, Hugo Takada, Masayuki Nagahata, Koji Iwamiya, Shin-Ichiro Division of Electrical Engineering and Computer Science Faculty of Engineering Nagasaki University Bunkyo-machi 1-14 Nagasaki 852-8521 Japan AG Technische Akustik MMK TU München Archisstrasse 21 München 80333 Germany Communication Design Science Faculty of Design Kyushu University Shiobaru 4-9-1 Minami-ku Fukuoka 815-8540 Japan Department of Human Support System Faculty of Symbiotic Systems Science Fukushima University 1 Kanayagawa Fukushima 960-1296 Japan

ISBN: (纸本)9781618392800

Electric and hybrid electric vehicles (EV/HEV) have the advantage of being more environmentally friendly and quieter than internal combustion engine vehicles. However, reduced noise can also lead to potentially dangerous situations for pedestrians when an oncoming vehicle is inaudible due to background noise (e.g. Kerber and Fastl, internoise 2007). The installation of devices that produce warning sounds in vehicles to alert pedestrians is being considered in various countries. Because this is a global topic, it is of vital interest to determine whether there exist cross-cultural differences. Pilot studies on this topic were performed in Japan (Yamauchi et al., internoise 2010) and, with improved input devices and test procedure, in Germany (Menzel et al., DAGA 2011). The level of three possible warning sounds (engine noise, car horn, and band-pass noise) were adjusted in presence of four different urban background sounds (busy street, residential area, heavy traffic, and shopping area) in laboratory environments. In the first part of the experiments, subjects were asked to adjust the level of the warning sounds so that they were clearly audible and could be reliably detected in the background noise. In the second part the goal was to adjust the level so that the warning sounds were just audible. The results of the adjustments showed no significant difference between the two subjects groups. The results were discussed in view of inter-individual and intraindividual differences. Moreover, the results were compared to current recommendations for sound levels of warning sounds in quiet vehicles.

关键词： Acoustic noise

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