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COVAD: Content-oriented video anomaly detection using a self attention-based deep learning model

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Virtual Reality & Intelligent Hardware 2023年第1期5卷 24-41页

作者： Wenhao SHAO Praboda RAJAPAKSHA Yanyan WEI Dun LI Noel CRESPI Zhigang LUO College of Computer National University of Defense TechnologyChangsha 410073China telecom sudparis IMTInstitut Polytechnique de ParisPalaiseau 91764France Zhengzhou College of Finance and Economics Zhengzhou 450000China

Background Video anomaly detection has always been a hot topic and has attracted increasing *** of the existing methods for video anomaly detection depend on processing the entire video rather than considering only the significant context. Method This paper proposes a novel video anomaly detection method called COVAD that mainly focuses on the region of interest in the video instead of the entire video. Our proposed COVAD method is based on an autoencoded convolutional neural network and a coordinated attention mechanism,which can effectively capture meaningful objects in the video and dependencies among different objects. Relying on the existing memory-guided video frame prediction network, our algorithm can significantly predict the future motion and appearance of objects in a video more effectively. Result The proposed algorithm obtained better experimental results on multiple datasets and outperformed the baseline models considered in our analysis. Simultaneously, we provide an improved visual test that can provide pixel-level anomaly explanations.

关键词： Video surveillance Video anomaly detection Machine learning Deep learning Neural network Coordinate attention

Prediction of urban human mobility using large-scale taxi traces and its applications

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Frontiers of Computer Science 2012年第1期6卷 111-121页

作者： Xiaolong LI Gang PAN Zhaohui WU Guande QI Shijian LI Daqing ZHANG Wangsheng ZHANG Zonghui WANG Department of Computer Science Zhejiang UniversityHangzhou 310027China institut telecom sudparis 91011 Evry CedexFrance

This paper investigates human mobility patterns in an urban taxi transportation system. This work focuses on predicting human mobility from discovering patterns of in the number of passenger pick-ups quantity （PUQ） from urban hotspots. This paper proposes an improved ARIMA based prediction method to forecast the spatial-temporal variation of passengers in a hotspot. Evaluation with a large-scale real- world data set of 4 000 taxis＇ GPS traces over one year shows a prediction error of only 5.8%. We also explore the applica- tion of the pl^di^fioti approach to help drivers find their next passetlgerS, The sinatllation results using historical real-world data demonstrate that, with our guidance, drivers can reduce the time taken and distance travelled, to find their next pas- senger＋ by 37.1% and 6.4% respectively,

关键词： urban traffic GPS traces hotspots human mo-bility prediction auto-regressive integrated moving average(ARiMA)

Testing protocols in Internet of Things by a formal passive technique

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Science China(Information Sciences) 2014年第3期57卷 6-18页

作者： Xiaoping CHE Stephane MAAG Insititut Mines-telecom/telecom sudparis CNRS UMR 5157Evry 91000France

In recent years,Extensible Messaging and Presence Protocol(XMPP)is gaining momentum in Internet of Things(IoT).It has been widely used in chatting,message exchanging and unique *** a matter of course,it raises an interesting issue:how to formally test the conformance and performance of XMPP in IoT *** conformance testing of communicating protocols is a functional test that verifies whether the behaviors of the protocol satisfy defined requirements,performance testing is a qualitative and quantitative test that aims at checking whether the performance requirements of the protocol are satisfied under certain *** this paper,we present a logic-based passive testing approach that can test both the conformance and the performance of XMPP protocol through real execution traces and formally specified *** evaluate and assess our methodology,we present a developed prototype and the experiments with a set of XMPP ***,the relevant verdicts and conclusions are provided.

关键词： Internet of Things passive testing formal methods XMPP

A P2P Platform for Collaborative Aggregated Multimedia Sharing

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Communications and Network 2013年第3期5卷 529-543页

作者： Ines Fakhfakh Hongguang Zhang Marc Girod-Genet UMR CNRS 5157 Telecom SudParis Institut Mines-Telecom Evry France

Peer-to-peer technologies have emerged as a powerful and scalable communication model for large scale content shar-ing. However, they are not yet provided with optimized heterogeneous aggregated content management functionality since they lack rich semantic specifications. To overcome these shortcomings, we elaborated a reference model of P2P architecture for a dynamic aggregation, sharing and retrieval of heterogeneous multimedia contents (simple or aggre-gated). This architecture was mainly developed under the CAM4Home European research project and is fully based on the CAM4Home semantic metadata model. This semantic model relies on RDF (Resource Description Framework) and is rich (but simple enough), extensible and dedicated for the description of any kind of multimedia *** this paper, we detail and evaluate an original semantic-based community network architecture for heterogeneous multimedia con-tent sharing and retrieval. Within the presentedarchitecture, multimedia contents are managed according to their asso-ciated CAM4Home semantic metadata through a structured P2P topology. This topology relies on a semantically en-hanced DHT (Distributed Hash Table) and is also provided with an additional indexing system for offering semantic storage and search facilities and overcoming the problem of exact match keywords in DHTs.

关键词： P2P DHT RDF Semantics Metadata Semantic Indexing and Search Multimedia Content Sharing Community Networking

Online conflict resolution strategies for human activity recognition in smart homes

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Journal of Control and Decision 2023年第3期10卷 402-416页

作者： Amina Jarraya Amel Bouzeghoub Amel Borgi Facultédes Sciences de Tunis Universitéde Tunis El ManarTunisTunisia Samovar Télécom SudParisInstitut Polytechnique de ParisPalaiseauFrance Facultédes Sciences de Tunis Institut Supérieur d’InformatiqueUniversitéde Tunis El ManarTunisTunisia

DCR-OL is a Distributed Collaborative Reasoning multi-agent model with an Online Learning thataims to identify human activities in smart homes from distributed, heterogeneous and dynamicsensor data. In this model, distributed learning agents with diverse classifiers, detect sensorstream data, make local predictions, communicate and collaborate to identify current ***, they learn from their collaborations to improve their own performance in activity *** resolution strategies are applied to generate one final predicted activity when thelocal predicted activity of an agent is different from received predicted activities of other *** this paper, two conflict resolution strategies using online learning, w-max-trust and w-maxfreq,are proposed. We experimentally test these strategies by performing an evaluation studyon the Aruba dataset. The obtained results indicate an enhancement in terms of accuracy and Fmeasuremetrics compared to the offline strategies max-trust and max-freq and also to the onlineexisting one max-wPerf .

关键词： Human activity recognition distributed reasoning learning agents smart homes online learning conflict resolution strategies sensor data stream

Personal Information Self-Management:A Survey of Technologies Supporting Administrative Services

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Journal of Computer Science & Technology 2021年第3期36卷 664-692页

作者： Paul Marillonnet Maryline Laurent Mikaël Ates Entr'ouvert Paris 75014France SAMOVAR Télécom SudParisInstitut Polytechnique de ParisEvry 91000France

This paper presents a survey of technologies for personal data self-management interfacing with administrative and territorial public service *** classifies a selection of scientific technologies into four categories of solutions:Personal Data Store(PDS),Identity Manager(IdM),Anonymous Certificate System and Access Control Delegation *** category,along with its technological approach,is analyzed thanks to 18 identified functional criteria that encompass architectural and communication aspects,as well as user data lifecycle *** originality of the survey is ***,as far as we know,there is no such thorough survey covering such a panel of a dozen of existing ***,it is the first survey addressing Personally Identifiable Information(PII)management for both administrative and private service ***,this paper achieves a functional comparison of solutions of very different technical *** outcome of this paper is the clear identification of functional gaps of each *** a result,this paper establishes the research directions to follow in order to fill these functional gaps.

关键词： personal information management privacy enforcement user-centric solution technological survey

Understanding bike trip patterns leveraging bike sharing system open data

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Frontiers of Computer Science 2017年第1期11卷 38-48页

作者： Longbiao CHEN Xiaojuan MA Thi-Mai-Trang NGUYEN Gang PAN Jeremie JAKUBOWICZ institut Mines-telecom Telecom SudParis UMR CNRS Samovar Evry 91000 France Laboratoire d'Informatique de Paris 6 (LIP6) University of Paris 6 Paris 75005 France College of Computer Science Zhejiang University Hangzhou 310027 China Department of Computer Science and Engineering Hong Kong University of Science and Technology Hong Kong China

Bike sharing systems are booming globally as a green and flexible transportation mode, but the flexibility also brings difficulties in keeping the bike stations balanced with enough bikes and docks. Understanding the spatio-temporal bike trip patterns in a bike sharing system, such as the popular trip origins and destinations during rush hours, is important for researchers to design models for bike scheduling and sta- tion management. However, due to privacy and operational concerns, bike trip data are usually not publicly available in many cities. Instead, the station feeds about real-time bike and dock number in stations are usually public, which we refer to as bike sharing system open data. In this paper, we propose an approach to infer the spatio-temporal bike trip patterns from the public station feeds. Since the number of possible trips （i.e., origin-destination station pairs） is much larger than the number of stations, we define the trip infer- ence as an ill-posed inverse problem. To solve this problem, we identify the sparsity and locality properties of bike trip patterns, and propose a sparse and weighted regularization model to impose both properties in the solution. We evaluate our method using real-world data from Washington, D.C. and New York City. Results show that our method can effectively infer the spatio-temporal bike trip patterns and outperform the baselines in both cities.

关键词： bike sharing system open data ill-posed inverse problems urban computing

Middleware technologies for cloud of things： a survey

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Digital Communications and Networks 2018年第3期4卷 176-188页

作者： Amirhossein Farahzadi Pooyan Shams Javad Rezazadeh Reza Farahbakhsh Dept. of Electrical and Computer Engineering Islamic Azad University North Tehran Branch Tehran Iron institut Mines telecom and Universite Paris Saclay Telecom SudParis CNRS Lab UMR5157 91011 Evry France School of Computing and Communication Faculty of Engineering and IT University of Technology Sydney Australia

The next wave of communication and applications will rely on new services provided by the Internet of Things which is becoming an important aspect in human and machines future. IoT services are a key solution for providing smart environments in homes, buildings, and cities. In the era of massive number of connected things and objects with high growth rate, several challenges have been raised, such as management, aggregation, and storage for big produced data. To address some of these issues, cloud computing emerged to the IoT as Cloud of Things (CoT), which provides virtually unlimited cloud services to enhance the large-scale IoT platforms. There are several factors to be considered in the design and implementation of a CoT platform. One of the most important and challenging problems is the heterogeneity of different objects. This problem can be addressed by deploying a suitable “middleware” which sits between things and applications as a reliable platform for communication among things with different interfaces, operating systems, and architectures. The main aim of this paper is to study the middleware technologies for CoT. Toward this end, we first present the main features and characteristics of middlewares. Next, we study different architecture styles and service domains. Then, we present several middlewares that are suitable for CoT-based platforms and finally, a list of current challenges and issues in the design of CoT-based middlewares is discussed.

关键词：通信技术物联网发展现状中国

Steady-State Behavior of Semiconductor Laser Diodes Subject to Arbitrary Levels of External Optical Feedback

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Optics and Photonics Journal 2013年第1期3卷 128-134页

作者： Qin Zou institut Mines-telecom Telecom SudParis Département Electronique et Physique UMR 5157 CNRS Evry France

This paper investigates the steady-state behavior of a semiconductor laser subject to arbitrary levels of external optical feedback by means of an iterative travelling-wave (ITW) model. Analytical expressions are developed based on an iterative equation. We show that, as in good agreement with previous work, in the weak-feedback regime of operation except for a phase shift the ITW model will be simplified to the Lang-Kobayashi (LK) model, and that in the case where this phase shift is equal to zero the ITW model is identical to the LK model. The present work is of use in particular for distinguishing the coherence-collapse regime from the strong-feedback regime where low-intensity-noise and narrow-linewidth laser operation would be possible at high feedback levels with re-stabilization of the compound laser system.

关键词： Semiconductor Lasers External Optical Feedback Iterative Traveling-Wave Model Compound Cavity Modes Lang-Kobayashi Model External Cavity Modes Feedback Lasers