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IEEE Symposium on Real-Time and Embedded Technology and Applications

作者： Isaac Amundson Xenofon Koutsoukos Janos Sallai Akos Ledeczi Institute for Software Integrated Systems (ISIS) Department of Electrical Engineering and Computer Science Vanderbilt University Nashville TN USA

Over the past decade, wireless sensor networks have advanced in terms of hardware design, communication protocols, resource efficiency, and other aspects. Recently, there has been growing interest in mobile wireless sensor networks, and several small-profile sensing devices that are able to control their own movement have already been developed. Unfortunately, resource constraints inhibit the use of traditional navigation methods, because these typically require bulky, expensive, and sophisticated sensors, substantial memory and processor allocation, and a generous power supply. Therefore, alternative navigation techniques are required. In this paper we present TripNav, a localization and navigation system that is implemented entirely on resource-constrained wireless sensor nodes. Localization is realized using radio interferometric angle of arrival estimation, in which bearings to a mobile node from a small number of infrastructure nodes are estimated based on the observed phase differences of an RF interference signal. The position of the mobile node is then determined using triangulation. A digital compass is also employed to keep the mobile node from deviating from the desired trajectory. We demonstrate using a real-world implementation that a resource-constrained mobile sensor node can accurately perform waypoint navigation with an average position error of 0.95 m.

关键词： Mobile communication Robot sensing systems Navigation Hardware Wireless sensor networks Radio interferometry Trajectory

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Transmission Control Policy design for decentralized detection in sensor networks

Transmission Control Policy design for decentralized detecti...

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International Conference on Distributed Computing in Sensor systems (DCOSS)

作者： Ashraf Tantawy Xenofon Koutsoukos Gautam Biswas Institute of Software Integrated Systems (ISIS) Department of Electrical Engineering and Computer Science Vanderbilt University Nashville TN USA

A Wireless Sensor Network (WSN) deployed for detection applications has the distinguishing feature that sensors cooperate to perform the detection task. Therefore, the decoupled design approach typically used to design communication networks, where each network layer is designed independently, does not lead to the desired optimal detection performance. Recent work on decentralized detection has addressed the design of MAC and routing protocols for detection applications by considering independently the Quality of Information (QoI), Channel State Information (CSI), and Residual Energy Information (REI) for each sensor. However, little attention has been given to integrate the three quality measures (QoI, CSI, REI) in the complete system design. In this work, we pursue a cross-layer approach to design a QoI, CSI, and REI-aware Transmission Control Policy (TCP) that coordinates communication between local sensors and the fusion center, in order to maximize the detection performance. We formulate and solve a constrained nonlinear optimization problem to find the optimal TCP design variables. We compare our design with the decoupled approach, where each layer is designed separately, in terms of the delay for detection and WSN lifetime.

关键词： Wireless sensor networks Wireless communication Optimization Channel models Media Access Protocol Delay

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PaNeCS: A modeling language for passivity-based design of networked control systems

PaNeCS: A modeling language for passivity-based design of ne...

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Mediterranean Conference on Control and Automation (MED)

作者： Emeka Eyisi Joseph Porter Nicholas Kottenstette Xenofon Koutsoukos Janos Sztipanovits Institute of Software Integrated Systems (ISIS) Department of Electrical Engineering and Computer Science Vanderbilt University Nashville TN USA

The rapidly increasing use of information technology in constructing real-world systems has led to the urgent need for a sound systematic approach in designing networked control systems. Communication delays and other uncertainties complicate the development and analysis of these systems. This paper describes a prototype modeling language for the design of networked control systems using passivity to decouple control design from network uncertainties. The modeling language includes an integrated analysis tool to check for passivity and code generators for simulation in MATLAB/Simulink using the TrueTime platform modeling toolbox and for running actual experiments. The resulting designs are by construction robust to platform effects and implementation uncertainties.

关键词： Biological system modeling

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No-go theorem for one-way quantum computing on naturally occurring two-level systems

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Physical Review A 2011年第5期83卷 050301(R)-050301(R)页

作者： Jianxin Chen Xie Chen Runyao Duan Zhengfeng Ji Bei Zeng Department of Computer Science and Technology Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing China Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts USA Centre for Quantum Computation and Intelligent Systems (QCIS) Faculty of Engineering and Information Technology University of Technology Sydney New South Wales Australia Perimeter Institute for Theoretical Physics Waterloo Ontario Canada State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing China Institute for Quantum Computing and Department of Combinatorics and Optimization University of Waterloo Waterloo Ontario Canada

The ground states of some many-body quantum systems can serve as resource states for the one-way quantum computing model, achieving the full power of quantum computation. Such resource states are found, for example, in spin-52 and spin-32 systems. It is, of course, desirable to have a natural resource state in a spin-12, that is, qubit system. Here, we give a negative answer to this question for frustration-free systems with two-body interactions. In fact, it is shown to be impossible for any genuinely entangled qubit state to be a nondegenerate ground state of any two-body frustration-free Hamiltonian. What is more, we also prove that every spin-12 frustration-free Hamiltonian with two-body interaction always has a ground state that is a product of single- or two-qubit states. In other words, there cannot be any interesting entanglement features in the ground state of such a qubit Hamiltonian.

关键词： QUANTUM computers QUANTUM theory HAMILTONIAN operator HAMILTONIAN systems PHYSICS

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Students' perceptions of the differences between formal and informal learning 11

Students' perceptions of the differences between formal and ...

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7th International Computing Education Research Workshop, ICER 2011

作者： Boustedt, Jonas Eckerdal, Anna McCartney, Robert Sanders, Kate Thomas, Lynda Zander, Carol Division of Technology and Environment University of Gävle Gävle Sweden Department of Information Technology Uppsala University Uppsala Sweden Department of Computer Science and Engineering University of Connecticut Storrs CT United States Mathematics and Computer Science Department Rhode Island College Providence RI United States Department of Computer Science Aberystwyth University Aberystwyth United Kingdom Computing and Software Systems University of Washington Bothell Bothell WA United States

ISBN: (纸本)9781450308298

Research has shown that most learning in the workplace takes place outside of formal training and, given the swiftly changing nature of the field, computer science graduates more than most workers, need to be able to learn computing topics outside of organized classes. In this paper we discuss students' perceptions of the difference between formal and informal learning of computing topics, based on three datasets: essays collected from a technical writing course at a single university;the results of a brainstorming exercise conducted in the same course;and semi-structured interviews conducted at six institutions in three countries. The students report strengths and weaknesses in informal learning. On the one hand, they are motivated, can choose their level of learning, can be more flexible about how they learn, and often retain the material better. On the other hand, they perceive that they may miss important aspects of a topic, learn in an ad hoc way, and have difficulty assessing their learning. © 2011 ACM.

关键词： Students

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Performance evaluation of backoff algorithms for medium access in wireless networks

Performance evaluation of backoff algorithms for medium acce...

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International Conference on Selected Topics in Mobile and Wireless Networking (iCOST)

作者： Antoniy Ganchev Lata Narayanan Chadi Assi Department of Computer Science and Software Engineering Concordia University Montreal Canada Concordia Institute of Information Systems Engineering Concordia University Montreal Canada

Consider a backoff algorithm for medium access in wireless networks where a node chooses with probability 1-q to transmit right away and with probability q to transmit after CW slots, where CW is the maximum value of the contention window. We study a variation of the 802.11 protocol called XVBEB which uses the above backoff scheme and give a theoretical analysis of its saturation throughput. Simulation results show that the throughput of XVBEB is better than that of 802.11 for saturated CBR traffic. Furthermore, XVBEB also exhibits lower packet loss, delay and delay variation than 802.11 for both VBR and VoIP traffic for a variety of load conditions.

关键词： Throughput Protocols IEEE 802.11 Standards Delay Multiaccess communication Equations Markov processes

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On the need for data flow graph visualization of Forensic Lucid programs and encoded evidence, and their evaluation by GIPSY

On the need for data flow graph visualization of Forensic Lu...

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Annual Conference on Privacy, Security and Trust, PST

作者： Serguei A. Mokhov Joey Paquet Mourad Debbabi Department of Computer Science and Software Engineering Concordia University Montreal Canada Concordia Institute for Information Systems Engineering Concordia University Montreal Canada

Lucid programs are data-flow programs and can be visually represented as data flow graphs (DFGs) and composed visually. Forensic Lucid, a Lucid dialect, is a language to specify and reason about cyberforensic cases. It includes the encoding of the evidence (representing the context of evaluation) and the crime scene modeling in order to validate claims against the model and perform event reconstruction, potentially within large swaths of digital evidence. To aid investigators to model the scene and evaluate it, instead of typing a Forensic Lucid program, we propose to expand the design and implementation of the Lucid DFG programming onto Forensic Lucid case modeling and specification to enhance the usability of the language and the system. We briefly discuss the related work on visual programming and DFG modeling in an attempt to define and select one approach or a composition of approaches for Forensic Lucid based on various criteria such as previous implementation, wide use, formal backing in terms of semantics and translation. In the end, we solicit the readers' constructive, opinions, feedback, comments, and recommendations within the context of this short discussion.

关键词： Forensics Visualization Three dimensional displays Semantics Unified modeling language Computational modeling

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A CSMA-based approach for detecting composite data aggregate events with collaborative sensors in WSN

A CSMA-based approach for detecting composite data aggregate...

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International Conference on computer Supported Cooperative Work in Design

作者： Yang, Chi Ren, Kaijun Yang, Zhimin Gong, Peng Liu, Chang School of Computer Science and Software Engineering University of Western Australia M002 35 Stirling Highway Crawley WA 6009 Australia College of Computer National University of Defense Technology Changsha Hunan 410073 China Department of Computer Shandong University at Weihai Weihai China Anhui Wenda Information and Technology College Hefei 231201 China CS3-Centre for Complex Software Systems and Services Swinburne University of Technology Melbourne 3122 Australia

ISBN: (纸本)9781457703874

Nowadays, wireless sensor networks are widely used to monitor real time events and answer the ad hoc queries from a certain member node. However, computing and maintaining the information of aggregate queries in event monitoring wireless sensor networks incurs high spatial and temporal overhead for storage and transmission where potentially high volumes of unnecessary data may run through with changing time. Failure of processing that data can lead to unsuccessful event detection which can be very dangerous and costly in real world application. In order to reduce the overhead caused by unnecessary data for aggregate, suppression techniques such as data fusion, data sharing, data prediction, lossless data compression and base station side query rewriting are widely discussed in the WSN research community. In this paper, a technique which makes use of the spatial data relationship of local sensor nodes collaboratively is proposed to rein the detection of composite events with data aggregate. An empirical study is carried out to show the efficiency of the new technique. In addition, the new algorithm is compared to the previous event detection algorithms without spatial data suppression technique to demonstrate the significant performance gains. © 2011 IEEE.

关键词： Chemical detection

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QoS-aware Deployment of Network of Virtual Appliances Across Multiple Clouds

QoS-aware Deployment of Network of Virtual Appliances Across...

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IEEE International Conference on Cloud Computing Technology and Science (CloudCom)

作者： Amir Vahid Dastjerdi Saurabh Kumar Garg Rajkumar Buyya Cloud Computing and Distributed Systems (CLOUDS) Laboratory Department of Computer Science and Software Engineering University of Melbourne Parkville VIC Australia

Cloud computing paradigm allows on-demand access to computing and storages services over the Internet. To solve the complexity of application deployment in Cloud infrastructure, virtual appliances, pre-configured, ready-to-run applications are emerging as a breakthrough technology. However, an automated approach for deploying network of appliances is required to guarantee minimum deployment cost, low latency, and high reliability. In this paper, we propose and compare two different deployment approaches: Forward-checking-based backtracking (FCBB) and genetic-based. They take into account Quality of Service (QoS) criteria such as reliability, data communication cost, and latency between multiple Clouds to choose the most appropriate combination of virtual machines and appliances. We evaluate our approach using a real case study and different request types. Experimental results show both algorithms reach near optimal solution. Further, we investigate effects of factors such as latency requirements, and data communication between appliances on the performance of the algorithms and placement of appliances across multiple Clouds.

关键词： Home appliances Quality of service Servers Monitoring Cloud computing Availability

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IEEE Southeastcon

作者： Adam Harris James M. Conrad Department of Electrical and Computer Engineering and Department of Software and Information Systems University of North Carolina Charlotte Charlotte NC USA Department of Electrical and Computer Engineering University of North Carolina Charlotte Charlotte NC USA

Robotic simulators, frameworks, and related toolkits are very important in today's research community. The need to accurately simulate movements, algorithms, and interactions with the real world is quickly becoming a major research focus as humans and robots interact in more situations and differently than ever before. This is a survey of popular robotics simulators and some of the main frameworks and toolkits that are used to help bring robotics simulations to a one-to-one relationship with real-world interaction.

关键词： Robot sensing systems Engines Physics Robot kinematics Hardware

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