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International Conference on Acoustics, Speech, and Signal Processing (ICASSP)

作者： Jin Li Jarmo Takala Moncef Gabbouj Hexin Chen Department of Information Technology Tampere University of Technology Tampere Finland School of Communication Engineering Jilin University Changchun China

The discrete cosine transform (DCT) is widely used in image/video coding standards. However, since most DCT coefficients will be quantized to zeros, a large number of redundant computations are introduced. This paper presents an early detection algorithm to predict zero-quantized DCT coefficients for fast JPEG encoding. Based on the theoretical analysis for 2-D DCT and quantization in JPEG standard, we derive a sufficient condition under which each quantized coefficient becomes zero. Finally, the transform of the zero-quantized coefficients is omitted. Experimental results show that the proposed algorithm can significantly reduce the redundant computations and speed up the image encoding. Moreover, it doesn't cause any performance degradation. Computational reduction also implies longer battery lifetime and energy economy for digital applications.

关键词： detection algorithms Discrete cosine transforms Image coding Encoding Quantization Degradation Sufficient conditions Computational complexity Karhunen-Loeve transforms Portable computers

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Minimization of Error in Pitch detection algorithm using Discrete Fractional Cosine Transform

Minimization of Error in Pitch Detection algorithm using Dis...

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Australasian Telecommunication Networks and Applications Conference, ATNAC

作者： Md. Kamrul Hasan Md. Lutful Kabir Department of Electrical and Electronic Engineering Bangladesh University of Engineering and Technology Dhaka Bangladesh

A novel Discrete Fractional Cosine Transform implementation for pitch estimation of noisy speech using dominant harmonic is introduced in this paper. The basic idea is to preprocess the speech signal with discrete fractional cosine transform before using the rectified dominant harmonic for signal reshaping. The performance of the proposed method is tested and compared with the latest previous method using Keele pitch extraction reference database. Comparative results show that the proposed method can detect pitch with better accuracy in terms of gross and fine pitch error as compared to the latest technique.

关键词： Minimization methods detection algorithms Discrete transforms Discrete cosine transforms Kernel Speech processing Signal processing algorithms Time frequency analysis Speech enhancement Speech coding

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Joint MAP detection for MIMO-OFDM Systems

Joint MAP Detection for MIMO-OFDM Systems

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IEEE GLOBECOM 2008 - 2008 IEEE Global Telecommunications Conference

作者： Zhendong Luo Fan Yang Dawei Huang Institute of Communication Standards Research MII China Academy of Telecommunication Research CATR Beijing China School of Information Engineering Beijing University of Posts and Telecommunications Beijing China Bell Laboratories Research China Alcatel-Lucent Beijing China

In this paper, a joint maximum a posteriori (MAP) detection algorithm is proposed for multiple-input multiple-output orthogonal frequency division multiplexing (MIMO- OFDM) systems. Without the need of estimating the channel state information (CSI), it can directly compute the a posteriori probability (APP) of the transmitted data and generate the detection results under the MAP criterion by efficient iterative processing. Based on the idea of list sphere decoding, we also present a fast searching algorithm to further reduce its complexity in the cases of large numbers of transmit antennas and high data rates. Computer simulation shows that even without the help of channel estimation, the proposed algorithm with a few iterations can approximately attain the performance of the optimal detector using the perfect CSI.

关键词： OFDM Iterative algorithms detection algorithms MIMO State estimation Channel state information Iterative decoding Transmitting antennas Computer simulation Channel estimation

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SIGNAL PROCESSING algorithms FOR STARING SINGLE PIXEL HYPERSPECTRAL SENSORS

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International Journal of High Speed Electronics and Systems 2008年第3期18卷 661-673页

作者： DIMITRIS MANOLAKIS MICHAEL ROSSACCI ERIN O'DONNELL FRANCIS M. D'AMICO MIT Lincoln Laboratory 244 Wood Street Lexington MA 02420 U.S.A. U.S. Army Edgewood Chemical and Biological Center Aberdeen Proving Ground MD 21010 U.S.A

Remote sensing of chemical warfare agents (CWA) with stand-off hyperspectral sensors has a wide range of civilian and military applications. These sensors exploit the spectral changes in the ambient photon flux produced thermal emission or absorption after passage through a region containing the CWA cloud. In this work we focus on (a) staring single-pixel sensors that sample their field of view at regular intervals of time to produce a time series of spectra and (b) scanning single or multiple pixel sensors that sample their FOV as they scan. The main objective of signal processing algorithms is to determine if and when a CWA enters the FOV of the sensor. We shall first develop and evaluate algorithms for staring sensors following two different approaches. First, we will assume that no threat information is available and we design an adaptive anomaly detection algorithm to detect a statistically-significant change in the observed spectrum. The algorithm processes the observed spectra sequentially-in-time, estimates adaptively the background, and checks whether the next spectrum differs significantly from the background based on the Mahalanobis distance or the distance from the background subspace. In the second approach, we will assume that we know the spectral signature of the CWA and develop sequential-in-time adaptive matched filter detectors. In both cases, we assume that the sensor starts its operation before the release of the CWA; otherwise, staring at a nearby CWA-free area is required for background estimation. Experimental evaluation and comparison of the proposed algorithms is accomplished using data from a long-wave infrared (LWIR) Fourier transform spectrometer.

关键词： Hypespectral Imaging chemical sensing biological sensing detection algorithms

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detection of web subsites: Concepts, algorithms, and evaluation issues 07

Detection of web subsites: Concepts, algorithms, and evaluat...

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IEEE/WIC/ACM International Conference on Web Intelligence

作者： Rodrigues, Eduarda Mendes Milic-Frayling, Natasa Fortuna, Blaz Microsoft Res Ltd 7 J J Thomson Ave Cambridge CB3 0FZ England Jozef Stefan Inst Dept Knowledge Technol Ljubljana 1000 Slovenia

ISBN: (纸本)9780769530260

Web sites are often organized into several regions, each dedicated to a specific topic or serving a particular function. From a user's perspective, these regions typically form coherent sets of pages characterized by a distinct navigation structure and page layout-we refer to them as subsites. In this paper we propose to characterize Web site structure as a collection of subsites and devise a method for detecting subsites and entry points for subsite navigation. In our approach we use a new model for representing Web site structure called Link Structure Graph (LSG). The LSG captures a complete hyperlink structure of a Web site and models link associations reflected in the page layout. We analyze a sample of Web sites and compare the LSG based approach to commonly used statistics for Web graph analysis. We demonstrate that LSG approach reveals site properties that are beyond the reach of standard site models. Furthermore, we devise a method for evaluating the performance of subsite detection algorithms and provide evaluation guidelines.

关键词： Navigation detection algorithms Machine learning algorithms Guidelines Web page design Algorithm design and analysis Statistical analysis Web sites Web pages Training data

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Educating the Smart Grid

Educating the Smart Grid

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IEEE Energy 2030 Conference, ENERGY

作者： Jeffrey S. Katz IBM USA

The smart grid is entering the era of practical pilot projects and readiness to scale. This has been the result of a movement in technology, regulation, and a learning process for all involved. This paper discusses several areas of experience with the "intelligent utility network", IBM"s nomenclature for its smart grid concept. Topics addressed are the grid wise demonstration with the Department of Energy's Pacific Northwest Lab and other research work related to the IUN, projects in progress with customers to create the foundations of a smart grid, technology and architecture, and aspects for the enablement of alternative and distributed energy and plug-in hybrid electric vehicles. From a business perspective, the IBM IUN utility coalition and the IUN maturity model will be discussed.

关键词： Smart grids Security Energy efficiency Cooling USA Councils Intelligent networks Hybrid electric vehicles Performance analysis Algorithm design and analysis detection algorithms

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Macromobility prediction for high-priority resource reservation in wireless networks

Macromobility prediction for high-priority resource reservat...

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International Symposium on Wireless Communication Systems (ISWCS)

作者： Stefan Michaelis Andreas Lewandowski Kai Daniel Christian Wietfeld Communication Networks Institute Dortmund University Dortmund Germany

Efficient management of mobile network resources is a critical task for successful operation. Giving higher priority and quality of service to applications with a high return on invest value, demands for intelligent distribution of bit rates and radio access. The research approach proposed here is based on the fact, that users cannot move freely, but are restricted to streets or rails in position, direction and speed. Following the geographical topology while in motion some locations generate a unique signature by forcing the user to traverse similar sequences of base stations. The signatures can be revealed by applying pattern detection methods on the historical user movements, allowing to predict future positions of the user on a large time scale, especially to reserve resources for rescue workers. In this paper we discuss the effect of different attributes about the user's movement for the prediction quality on different pattern detection algorithms in order to improve and accelerate the process of rescue missions. Further the availability of these attributes will be discussed for different scenarios and validated by traces from an actual large scale HSDPA/GSM network.

关键词： Wireless networks Resource management Quality of service Bit rate Rails Topology Base stations detection algorithms Acceleration Availability

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A study to demonstrate the use of an air bag device to prevent fall-related injuries

A study to demonstrate the use of an air bag device to preve...

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IEEE Symposium on Bioinformatics and Bioengineering (BIBE)

作者： Toshiyo Tamura Takumi Yoshimura Masaki Sekine Department of Biomedical Engineering Graduate School of Engineering Chiba University Inage Chiba Japan Department of Medical and Welfare Engineering Tokyo Metropolitan College of Industrial Technology Arakawa Tokyo Japan

We sought to develop a fall-related injury prevention system using a telemetry acceleration and angular velocity monitor, and an air bag. In this study, we have developed a fall detection system using both acceleration and angular velocity signals and triggering the inflation of an air bag. Sixteen subjects mimicked falls and their acceleration waveforms were monitored. Then, we developed a fall detection algorithm that could detect signals 300 ms before the fall. This signal was used as a trigger to inflate the air bag to a capacity of 2.4 L. While the proposed system can aid in preventing fall-related injuries, further development is needed to miniaturize the inflation system.

关键词： Injuries Acceleration Angular velocity Accelerometers Biomedical engineering Monitoring Telemetry detection algorithms Hip Protection

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Research on Hybrid-ARQ Chase Combining algorithms in ZF-SIC V-BLAST

Research on Hybrid-ARQ Chase Combining Algorithms in ZF-SIC ...

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IEEE Conference on Wireless Communications and Networking

作者： He Wang Guoquan Lu Xiaofang Qin Kai Wu Yongyu Chang Xin Zhang Dacheng Yang Wireless Theories and Technologies Laboratory (WT&T) Beijing University of Posts and Telecommunications Beijing China

In the conventional zero-forcing successive interference cancellation (ZF-SIC) detection algorithm of vertical Bell-Labs layered space-time (V-BLAST) architecture, the detection algorithm does not attempt to eliminate the effect of the error propagation, which is significantly deleterious to hybrid automatic repeat request (H-ARQ) scheme using bit-level Chase combining. Based on two ordering approaches respectively, we propose two novel H-ARQ bit-level Chase combining algorithms in this paper, which employ a new log-likelihood ratio (LLR) calculation algorithm to minimize the effect of the error propagation. Additionally, we bring forward a new pairwise LLR combining technique to enhance the reliability of ordering stage considerably. Through simulation results, it is shown that the new proposed algorithms outperform the conventional ones in system performance.

关键词： MIMO Interference cancellation Automatic repeat request detection algorithms Diversity reception Physical layer Silicon carbide Communications Society Helium Isolation technology

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Hough detector with an OS CFAR processor in Presence of Randomly Arriving Impulse Interference

Hough detector with an OS CFAR processor in Presence of Rand...

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European Radar Conference (EURAD)

作者： Lyubka Doukovska Christo Kabakchiev Vladimir Kyovtorov Ivan Garvanov Institute of Information Technologies Bulgarian Academy of Sciences Sofia Bulgaria Faculty of Mathematics & Informatics Sofia University Sofia Bulgaria

In this paper we present the research results concerning the performance of Hough detector with an Order Statistic False Alarm Rate (OS CFAR) processor, in the presence of randomly arriving impulse interference with Poisson distributed flow and Raleigh amplitude distribution. In the presented contribution are investigated two types of Hough detectors with CFAR processors, in order to choose the most efficient one in the presence of clutter and randomly arriving impulse interference. The Hough detector with OS CFAR processor is compared to Hough detector with CA CFAR processor. The achieved results reveal that the Hough detector with the OS CFAR algorithm is more effective. The experimental results are obtained by numerical analysis. We have studied the detection probability and the average decision threshold of Hough detector with two types of CFAR processors. The results show that the use of this structure of Hough detector allows drastically reducing the detectability losses in comparison to the conventional OS CFAR detector and that it is effective for small signal-to-noise ratios. The research work is performed in MATLAB computational environment. The obtained analytical results for Hough detector with an Order Statistic CFAR processor can be used in both, radar and communication receiver networks.

关键词： Detectors Interference Radar detection detection algorithms Object detection Signal to noise ratio Statistical analysis Noise level Signal processing Information technology

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