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Optical Transmission, Switching, and Subsystems V

作者： Wong, Elaine Zhao, Xiaoxue Chang-Hasnain, Connie J. Hofmann, Werner Amann, Marcus C. ARC Special Research Centre on Ultra-Broadband Information Networks University of Melbourne Australia Victoria Research Laboratory NICTA Australia Dept of Electrical Engineering and Computer Science University of California Berkeley United States Walter Schottky Institute Technical University of Munich Germany

ISBN: (纸本)9780819469465

In this paper, we will discuss the utilization of optically injection-locked (OIL) 1.55 μm vertical-cavity surface-emitting lasers (VCSELs) for operation as low-cost, stable, directly modulated, and potentially uncooled transmitters, whereby the injection-locking master source is furnished by modulated downstream signals. Such a transmitter will find useful application in wavelength division multiplexed passive optical networks (WDM-PONs) which is actively being developed to meet the ever-increasing bandwidth demands of end users. Our scheme eliminates the need for external injection locking optical sources, external modulators, and wavelength stabilization circuitry. We show through experiments that the injection-locked VCSEL favors low injection powers and responds only strongly to the carrier but not the modulated data of the downstream signal. Further, we will discuss results from experimental studies performed on the dependence of OIL-VCSELs in bidirectional networks on the degree of Rayleigh backscattered signal and extinction ratio. We show that error-free upstream performance can be achieved when the upstream signal to Rayleigh backscattering ratio is greater than 13.4 dB, and with minimal dependence on the downstream extinction ratio. We will also review a fault monitoring and localization scheme based on a highly-sensitive yet low-cost monitor comprising a low output power broadband source and low bandwidth detectors. The proposed scheme benefits from the high reflectivity top distributed Bragg reflector mirror of the OIL-VCSEL, incurring only a minimal penalty on the upstream transmissions of the existing infrastructure. Such a scheme provides fault monitoring without having to further invest in the upgrade of customer premises.

关键词： Fiber optic networks

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Protecting IP Multimedia Subsystem (IMS) Service Delivery Platform from Time Independent Attacks

Protecting IP Multimedia Subsystem (IMS) Service Delivery Pl...

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International Symposium on Information Assurance and Security (IAS)

作者： Muhammad Sher Thomas Magedanz Faculty of Electrical Engineering & Computer Science Institute for Telecommunication System Next Generation Networks Integration (AV) Technical University Berlin Germany

With the emergence of mobile multimedia services, such as unified messaging, click to dial, cross network multiparty conferencing and seamless multimedia streaming services, the fixed-mobile convergence and voice-data integration has started, leading to an overall Internet-Telecommunications merger. The IP multimedia subsystem (IMS) is considered as the next generation service delivery platform in this converge communication world. It consists of modular design with open interfaces and enables the flexibility for providing multimedia services over IP technology. At parallel this open based emerging technology has security challenges from multiple communication platforms like IP, SIP and RTP. In this article our objective is to develop security model to protect IMS service delivery platform (SDP) from different time independent attacks e.g. SQL injection and media flow attacks. These attacks ultimately downfall the value added services. At the end we shall present the performance results at Fokus Fraunhofer Testbed to see the proposed solution for real world applications.

关键词： Protection

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On the road to genetic boolean matrix factorization

On the road to genetic boolean matrix factorization

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作者： Snášel, Václav Platoš, Jan Krömer, Pavel Húsek, Dušan Frolov, Alexander A. Department of Computer Science Faculty of Electrical Engineering and Computer Science VŠB - Technical University of Ostrava 17. listopadu 15 708 33 Ostrava - Poruba Czech Republic Institute of Computer Science Dept. of Neural Networks Academy of Sciences of Czech Republic Pod Vodárenskou věží 2 182 07 Prague Czech Republic Institute of Higher Nervous Activity and Neurophysiology Russian Academy of Sciences Butlerova 5a 117 485 Moscow Russia

Matrix factorization or factor analysis is an important task helpful in the analysis of high dimensional real world data. There are several well known methods and algorithms for factorization of real data but many application areas including information retrieval, pattern recognition and data mining require processing of binary rather than real data. Unfortunately, the methods used for real matrix factorization fail in the latter case. In this paper we introduce background and initial version of Genetic Algorithm for binary matrix factorization. © ICS AS CR 2007.

关键词： Boolean functions

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Mobile multimedia broadcasting vulnerability threats, attacks and security solutions

Mobile multimedia broadcasting vulnerability threats, attack...

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International Workshop on Mobile and Wireless Communications Network (MWCN)

作者： Muhammad Sher Thomas Magedanz Faculty of Electrical Engineering Computer Science Institute for Telecommunication System Next Generation Networks Integration (AV) Technical University of Berlin Fokus Fraunhofer Institute Berlin Germany

The IP Multimedia Subsystem (IMS) has emerged as next generation value added communication services including mobile multimedia broadcasting, multimedia conferencing, push to talk and presence etc on top of all IP networks. Offering multimedia streaming services across heterogeneous fixed and mobile networks have faced many challenges e.g. security, QoS, mobility and services management. In this article our objective is to identity vulnerability threats and attacks, and to study existing potential solutions for mobile multimedia broadcasting. The attacks possibilities are from multiple communication protocols suite i.e. Session Initiation Protocol (SIP) is used for session management, Diameter is used for authentication and authorization, Real-time Transport Protocol (RTP) & Real Time Streaming Protocol (RTSP) are used for media streaming on top of transport and IP infrastructure, therefore facing security challenges from three protocols domains. We will also present extended security by developing Intrusion Detection and Prevention (IDP) System to secure IMS based Mobile Multimedia Broadcasting communication from Denial-of-Service (DoS) attacks.

关键词： Multimedia communication Security Streaming media Mobile communication Digital multimedia broadcasting IP networks Multimedia systems

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An integrated simulation framework for cognitive automobiles

An integrated simulation framework for cognitive automobiles

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IEEE Symposium on Intelligent Vehicle

作者： Stefan Vacek Robert Nagel Thomas Batz Frank Moosmann Rudiger Dillmann Insitute for Computer Science and Engineering University of Karlsruhe Karlsruhe Germany Institute of Communication Networks Munich University of Technology München Germany Fraunhofer IITB Institute for Information and Data Processing Karlsruhe Germany Institute of Measurement and Control University of Karlsruhe Karlsruhe Germany

A cognitive automobile is a complex system. It is an indisputable fact that simulations are valuable tools for the development and testing of such complex systems. This paper presents an integrated closed-loop simulation framework which supports the development of a cognitive automobile. The framework aims at simulating complex traffic scenes in inner-city environments. The key features of the simulation are the generation of synthetic data for high level inference mechanisms, providing data for the analysis of car-to-car communication strategies and evaluation of cooperative vehicle behavior.

关键词： Automobiles Traffic control Communication system control Layout Analytical models Vehicle detection Intelligent vehicles System testing Decision making Path planning

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Bars problem solving - New neural network method and comparison

Bars problem solving - New neural network method and compari...

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6th Mexican International Conference on Artificial Intelligence, MICAI 2007

作者： Snášel, Václav Húsek, Dušan Frolov, Alexander Řezanková, Hana Moravec, Pavel Polyakov, Pavel Department of Computer Science FEECS VŠB - Technical University of Ostrava 17. listopadu 15 708 33 Ostrava-Poruba Czech Republic Institute of Computer Science Dept. of Neural Networks Academy of Sciences of Czech Republic Pod Vodárenskou věží 2 182 07 Prague Czech Republic Institute of Higher Nervous Activity and Neurophysiology Russian Academy of Sciences Butlerova 5a 117 485 Moscow Russia Department of Statistics and Probability University of Economics Prague W. Churchill sq. 4 130 67 Prague Czech Republic Institute of Optical Neural Technologies Russian Academy of Sciences Vavilova 44 119 333 Moscow Russia

ISBN: (纸本)9783540766308

Bars problem is widely used as a benchmark for the class of feature extraction tasks. In this model, artificial data set is generated as a Boolean sum of a given number of bars. We show that the most suitable technique for feature set extraction in this case is neural network based Boolean factor analysis. Results are confronted with several dimension reduction techniques. These are singular value decomposition, semi-discrete decomposition and non-negative matrix factorization. Even if these methods are linear, it is interesting to compare them with neural network attempt, because they are well elaborated and are often used for a similar tasks. We show that frequently used cluster analysis methods can bring interesting results, at least for first insight to the data structure. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Problem solving

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Comparison of neural network Boolean factor analysis method with some other dimension reduction methods on bars problem

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2nd International Conference on Pattern Recognition and Machine Intelligence, PReMI 2007

作者： Húsek, Dušan Moravec, Pavel Snášel, Václav Frolov, Alexander Řezanková, Hana Polyakov, Pavel Institute of Computer Science Dept. of Neural Networks Academy of Sciences of Czech Republic Pod Vodárenskou věží 2 182 07 Prague Czech Republic Department of Computer Science FEECS VŠB - Technical University of Ostrava 17. listopadu 15 708 33 Ostrava-Poruba Czech Republic Institute of Higher Nervous Activity and Neurophysiology Russian Academy of Sciences Butlerova 5a 117 485 Moscow Russia Department of Statistics and Probability University of Economics Prague W. Churchill sq. 4 130 67 Prague Czech Republic Institute of Optical Neural Technologies Russian Academy of Sciences Vavilova 44 119 333 Moscow Russia

ISBN: (纸本)3540770453

In this paper, we compare performance of novel neural network based algorithm for Boolean factor analysis with several dimension reduction techniques as a tool for feature extraction. Compared are namely singular value decomposition, semi-discrete decomposition and non-negative matrix factorization algorithms, including some cluster analysis methods as well. Even if the mainly mentioned methods are linear, it is interesting to compare them with neural network based Boolean factor analysis, because they are well elaborated. Second reason for this is to show basic differences between Boolean and linear case. So called bars problem is used as the benchmark. Set of artificial signals generated as a Boolean sum of given number of bars is analyzed by these methods. Resulting images show that Boolean factor analysis is upmost suitable method for this kind of data. © Springer-Verlag Berlin Heidelberg 2007.

关键词： Neural networks

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Image Analysis by Methods of Dimension Reduction

Image Analysis by Methods of Dimension Reduction

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computer Information Systems and Industrial Management Applications (CISIM)

作者： Pavel Moravec Vaclav Snasel Alexander Frolov Dusan Husek Hana Rezankova Pavel Polyakov Department of Computer Science FEECS VŠB – Technical University of Ostrava Ostrava-Poruba Czech Republic Institute of Higher Nervous Activity and Neurophysiology Russian Academy of Sciences Moscow Russia Institute of Computer Science Dept. of Neural Networks Academy of Sciences of Czech Republic Prague Czech Republic University of Economics Prague Prague Czech Republic Institute of Optical Neural Technologies Russian Academy of Sciences Moscow Russia

In this paper, we compare performance of several dimension reduction techniques, namely LSI, NMF, SDD, Boolean factor analysis, and cluster analysis. The qualitative comparison is evaluated on a collection of bars. We... 详细信息

关键词： Image analysis Bars Feature extraction Image retrieval Content based retrieval computer science Performance analysis Object recognition Indexing data mining

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Mining Maximal Frequent Patterns in a Unidirectional FP-tree

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Journal of Donghua University(English Edition) 2006年第6期000卷 105-109页

作者： SONG Jing-jing LIU Rui-xin WANG Yan JIANG Bao-qing SONG Jing-jing(Institute of Data and Knowledge Engineering Henan University Kaifeng 475001) LIU Rui-xin(Information Engineering Science Department Yellow River Conservancy Technical Institute Kaifeng 475003) WANG Yan(Institute of Data and Knowledge Engineering Henan University Kaifeng 475001 Department of Computer Science and Application Zhengzhou Institute of Aeronautical Industry Management Zhengzhou 450015)

Becausemining complete set of frequent patterns from dense database could be impractical, an interesting alternative has been proposed recently. Instead of mining the complete set of frequent patterns, the new model only finds out the maximal frequent patterns, which can generate all frequent patterns. FP-growth algorithm is one of the most efficient frequent-pattern mining methods published so far. However,because FP-tree and conditional FP-trees must be two-way traversable, a great deal memory is needed in process of mining. This paper proposes an efficient algorithm Unid_FP-Max for mining maximal frequent patterns based on unidirectional FP-tree. Because of generation method of unidirectional FP-tree and conditional unidirectional FP-trees, the algorithm reduces the space consumption to the fullest extent. With the development of two techniques:single path pruning and header table pruning which can cut down many conditional unidirectional FP-trees generated recursively in mining process, Unid_ FP-Max further lowers the expense of time and space.

关键词： data mining frequent pattern the maximal frequent pattern Unid _ FP-tree conditional Unid _ FP-tree

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WISENT: e-science for Energy Meteorology

WISENT: e-Science for Energy Meteorology

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IEEE International Conference on e-science and Grid Computing

作者： Wilhelm Hasselbring Detlev Heinemann Johannes Hurka Thomas Scheidsteger Ludger Bischofs Christoph Mayer Jan Ploski Guido Scherp Sina Lohmann Carsten Hoyer-Klick Thilo Erbertseder Gerhard Gesell Marion Schroedter-Homscheidt Gerd Heilscher Jochen Rehwinkel Stefan Rensberg Software Engineering Group Department of Computer Science University of Oldenburg Oldenburg Germany EHF Laboratory Department of Physics University of Oldenburg Oldenburg Germany Business Information Management OFFIS-Institute for Computer Science Oldenburg Germany German AeroSpace Centre (DLR) Institute of Atmospheric Physics Wessling Germany German AeroSpace Centre (DLR) Institute of Technical Thermodynamics Stuttgart Germany German Remote Sensing Data Center (DFD) German Aerospace Center Wessling Germany Meteocontrol GmbH Augsburg Germany

ISBN: (纸本)9781424430116

Our energy production increasingly depends on renewable energy sources, which impose new challenges for distributed and decentralized systems. One problem is that the availability of renewable energy sources such as wind and solar is not continuous as it is affected by meteorological factors. The challenge is to develop forecast methods capable of determining the level of power generation in near real-time in order to control power plants for optimal energy production. Another scenario is the identification of optimal locations for such power plants. In our collaborative project, these tasks are investigated in the domain of energy meteorology. For that purpose large data sources from many different sensors (e.g., satellites and ground stations) are the base for complex computations. The idea is to parallelize these computations in order to obtain significant speedup. This paper reports on an ongoing project employing Grid technologies in that context. Our approach to processing large data sets from a variety of heterogeneous data sources as well as ideas for parallel and distributed computing in energy meteorology are presented. Preliminary experience with several Grid middleware systems in our application scenario is discussed.

关键词： Meteorology Renewable energy resources Power generation Production systems Meteorological factors Wind forecasting Weather forecasting Load forecasting Solar power generation Wind energy generation

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