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2011 IEEE International Conference on Robotics and Automation(2011年IEEE世界机器人与自动化大会 ICRA 2011)

作者： Young-Sik Kwon Bae Lee In-Cheol Whang Whee-kuk Kim Byung-Ju Yi School of Electrical Engineering and Computer Science Hanyang UniversityKorea Doobae system Korea Department of Control and Instrumentation Engineering Korea UniversityKorea Department of Electronic System Engineering Hanyang UniversityKorea

This paper presents a new pipeline inspection robot that has multiple sensors for inspection of 80-100mm pipelines. The special feature of this robot is realization of driving and steering capability by using only two wheel chains. Compared to popularly employed pipeline robots using three wheel chains, the new design allows simple robot control and easy user interface, specially at T-branch. As another advantage, the flat shape of this robot allows mounting additional sensors on the both sides of the robot. The kinematics and three control modes are described. Finally, the performance of this robot system is verified by experimentation.

关键词： Mobile robots Wheels Pipelines Robot vision systems Cameras

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RAMC: A RSU-assisted multi-channel coordination MAC protocol for VANET

RAMC: A RSU-assisted multi-channel coordination MAC protocol...

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作者： Liu, Kai Guo, Jinhua Lu, Ning Liu, Fuqiang Wang, Xinhong Wang, Ping School of Electronics and Information Engineering Key Laboratory of Embedded System and Service Computing Tongji University 4800 Cao'an Road 201804 Shanghai China Department of Computer and Information Science University of Michigan-Dearborn 4901 Evergreen Rd Dearborn MI 48128 United States

Dedicated Short Range Communication (DSRC) employs one control channel for safety-oriented applications and six service channels for non-safety commercial applications. However, most existing multichannel schemes require all neighboring vehicles periodically (e.g. every 100 milliseconds) tune to the control channel for a full update of safety-oriented data before they can switch to the service channels for non-safety services. The safety exchange interval increases with the increase of traffic density. Consequently, under high traffic densities, the service channels are often completely idle while the control channel is congested. We propose a RSU Assisted Multi-channel Coordination MAC (RAMC) protocol that fully utilizes all channels to provide simultaneous safety and non-safety communications. Within the radio range of a roadside unit (RSU), vehicles are free to tune to any service channel. The RSU monitors all the safety messages being transmitted in both the control and service channels. Periodically, the RSU broadcasts a consolidated traffic view report to all neighboring vehicles in all channels. Therefore, a vehicle can operate in a service channel as long as it needs to achieve high throughput for non-safety applications, while maintaining adequate and timely safety awareness. Our simulation results show that the proposed RAMC protocol consistently achieves very high percentage of non-safety usage, while maintaining high safety message delivery ratios in various traffic density conditions. Copyright © 2011 The Institute of Electronics, Information and Communication Engineers.

关键词： Dedicated short range communications

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Extracting environmental constraints to make reactive system specifications realizable

Computer Software

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computer Software 2011年第3期28卷 132-146页

作者： Hagihara, Shigeki Shimakawa, Masaya Yonezaki, Naoki Kitamura, Yusuke Sekido, Satoshi Department of Computer Science Graduate School of Information Science and Engineering Institute of Technology Japan System Engineering Dept. Sony Business Solutions Corporation Value Creation Division Japan Department of Communications and Integrated Systems Graduate School of Science and Engineering Tokyo Institute of Technology Japan

Many fatal accidents of safety critical reactive systems have occurred in unexpected situations which had not been considered during design and test phases of the systems. To prevent these accidents, reactive systems should be designed to respond appropriately to any requests of any timing from their environments. Verifying this property in specification phase reduces the development costs of safety critical reactive systems. This property of a specification is well known as realizability. If a specification was found not to be realizable, we have to determine the flaws in the unrealizable specification. Unrealizability of a specification arises from arbitrary requirements given by system designers. From a different point of view, it can be thought that the unrealizable specification implicitly imposes a precondition on the behavior of environment, which a system can not control. If it is possible to obtain the precondition in intuitively comprehensive forms, this makes it easy for system designers to understand the cause of flaws in specifications. In this paper, we propose methods for deriving constraints on the behavior of environments, which is implicitly imposed by unrealizable specifications. Instead of realizability, we use strong satisfiability which is a necessary condition for realizability, due to the fact that many practical unrealizable specifications are also strongly unsatisfiable, and strong satisfiability have the advantage of lower complexity for analysis against realizability. These methods derive constraints in propositional linear temporal logic from Büchi automata representing specifications. The expressions of derived constraints are limited to simple and intuitively comprehensive forms where only two temporal operators appear successively. We give proofs for three correctness properties of our methods, i.e. the termination property, the soundness property, and the weakest constraints derivability. We also discuss complexity of our methods. Fi

关键词： Specifications

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Precoder design and convergence analysis of MIMO systems with Krylov subspace receivers

Precoder design and convergence analysis of MIMO systems wit...

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IEEE International Symposium on Information Theory

作者： Jun Tong Peter J. Schreier Steven R. Weller Signal and System Theory Group Universität Paderborn Germany School of Electrical Engineering and Computer Science University of Newcastle Australia

ISBN: (纸本)9781457705960

This paper studies the design and analysis of large multiple-input multiple-output (MIMO) systems with linear precoding and Krylov subspace receivers. We design precoders that can improve performance with low-rank receivers. We then introduce a tool based on potential theory to analyze the convergence behavior of the mean-squared error (MSE). The effectiveness of the proposed precoder and the superexponential convergence of the MSE are demonstrated 1 .

关键词： Receivers Convergence Complexity theory MIMO Eigenvalues and eigenfunctions Frequency modulation Limiting

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Distributed Storage Schemes for Controlling Data Availability in Wireless Sensor Networks

Distributed Storage Schemes for Controlling Data Availabilit...

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International Conference on Computational Intelligence and Security

作者： Shen Yulong Xi Ning Pei Qingqi Ma Jianfeng Xu Qijian Wu Zuoshun School of Computer Science and Technology Xidian University Xi'an Shanxi China School of Computer Science and Technology Xidian University Xi'an Shaanxi China Institute of China Electronic System Engineering Corporation Beijing China

The high unreliability of sensor nodes decreases the data availability. The replica management systems can provide very high data availability in the distributed systems. Due to energy limitations, the biggest challenge is the placement and management of replicas in the sensor networks. This paper addresses the problem of introducing sufficient redundancy with minimal communication cost to a network such that the entire network data can be retrieved after a failure. We formalize the replica placement problem and using failure models, give the optimal placement equation. Because the optimal placement equation is the 0-1 integer program problem which generally is very difficult to solve, we simplify the optimization equation by implicit enumeration method. The proposed data distribute scheme reduces the communication cost and ensure data availability in wireless sensor networks.

关键词： Availability Distributed databases Optimization Equations Mathematical model Wireless sensor networks

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Adaptive Disk I/O Scheduling for MapReduce in Virtualized Environment

Adaptive Disk I/O Scheduling for MapReduce in Virtualized En...

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International Conference on Parallel Processing (ICPP)

作者： Shadi Ibrahim Hai Jin Lu Lu Bingsheng He Song Wu Cluster and Grid Computing laboratory Services Computing Technology and System laboratory School of Computer Science and Technology Huazhong University of Science and Technology Wuhan China School of Computer Engineering Nanyang Technological University Singapore

Virtual machine (VM) interference has long been a challenging problem for performance predictability and system throughput for large-scale virtualized environments in the cloud. Such interferences are contributed by intertwined factors including the application's type, the number of con current VMs, and the VM scheduling algorithms used within the host. Since MapReduce has become an important data processing platform in the cloud, we investigate the impact of disk schedulers in Hadoop. Interestingly, our experimental results report a noticeable variation of the Hadoop performance between different applications when applying different disk pairs' schedulers in both the hypervisor and the virtual machines. Furthermore, a typical Hadoop application consists of different interleaving stages, each requiring different I/O workloads and patterns. As a result, the disk pairs' schedulers are not only sub-optimal for different MapReduce applications, but also sub-optimal for different sub-phases of the whole job. Accordingly, this paper presents a novel approach for adaptively tuning the disk pairs' schedulers in both the hypervisor and the virtual machines during the execution of a single MapReduce job. Our results show that MapReduce performance can be significantly improved; specifically, adaptive tuning of disk pairs' schedulers achieves a 25% performance improvement on a sort benchmark with Hadoop.

关键词： Benchmark testing Throughput Virtual machine monitors Interference Switches Virtual machining Tuning

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A nonlinear model predictive control using a continuation method and a step input constraint

A nonlinear model predictive control using a continuation me...

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2011 International Conference on Advanced Mechatronic systems, ICAMechS 2011

作者： Kogiso, Kota Masuda, Shiro Sato, Takao Faculty of System Engineering Tokyo Metropolitan University 6-6 Asahigaoka Hino Tokyo Japan Faculty of Electrical Engineering Mathematics and Computer Science Tokyo Metropolitan University 6-6 Asahigaoka Hino Tokyo Japan Department of Mechanical and Systems Engineering Graduate School of Engineering University of Hyogo 1-3-3 Higashikawasaki-cho Chuo-ku Kobe Hyogo Japan

ISBN: (纸本)9780955529375

The nonlinear model predictive control (MPC) needs to solve a two-point boundary-value problem (TP-BVP) at every sample time based on the receding horizon control strategy. However, solving a nonlinear algebraic equation for the TP-BVP requires high computational load, so developing an efficient computation method of the control law in real-time is a significant issue on the research of the nonlinear model predictive control. This paper proposes an efficient calculation method of the control law for nonlinear MPC. The proposed approach searches an optimal step-type input signal for a given performance index beforehand, then the input signal is successively updated using a continuation method. Hence, it can reduce the computation load because the number of the parameter to be optimized becomes one in the SISO case or the number of the inputs in the MIMO case, and solving TP-BVP can be avoided by a continuation method. In addition, the accuracy of the nonlinear algebraic equation, which gives the optimal condition, keeps well by analytically deriving the updating law of the MPC control law. A numerical example shows that the proposed method can reduce the computation load of the nonlinear MPC, while the accuracy of the optimal conditions given by the nonlinear algebraic equations keeps a tolerance level. © 2011 Intl Journal of Adv Mechatr.

关键词： Model predictive control

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Trajectory Tracking Control of Pendulum with Variable Length by Partial Energy Shaping * *

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IFAC Proceedings Volumes 2011年第1期44卷 10679-10684页

作者： Xin Xin Tatsuya Shinji Taiga Yamasaki Changyin Sun Faculty of Computer Science and System Engineering Okayama Prefectural University 111 Kuboki Soja Okayama 719-1197 Japan School of Automation Southeast University Nanjing 210096 China

Abstract This paper concerns a trajectory tracking control problem for a pendulum with variable length, which is an underactuated mechanical system of two degrees-of-freedom with a single input of adjusting the length of the pendulum. We aim to study whether it is possible to design a time-invariant control law to pump appropriate energy into the variable-length pendulum for achieving a desired swing motion (trajectory) with given desired energy and length of the pendulum. First, we show that it is difficult to avoid singular points in the controller designed by using the conventional energy-based control approach in which the total mechanical energy of the system is controlled. Second, we propose a tracking controller free of singular points by shaping only the kinetic energy of rotation and the potential energy of the pendulum and not utilizing the kinetic energy related to the motion along the rod. Third, we analyze globally the motion of the pendulum and clarify the stability issue of some closed-loop equilibrium points; and we also provide some conditions on control parameters for achieving the tracking objective. Finally, we present numerical simulation results to validate the presented theoretical results.

关键词： Trajectory tracking control nonlinear control pendulum swing variable length stability analysis energy shaping Lyapunov stability

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The SmartCane system: An assistive device for geriatrics 3

The SmartCane system: An assistive device for geriatrics

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3rd International ICST Conference on Body Area Networks, BODYNETS 2008

作者： Wu, Winston Au, Lawrence Jordan, Brett Stathopoulos, Thanos Batalin, Maxim Kaiser, William Vahdatpour, Alireza Sarrafzadeh, Majid Fang, Meika Chodosh, Joshua Electrical Engineering Department University of California Los Angeles United States Computer Science Department University of California Los Angeles United States Rheumatology and Geriatric Medicine VA Greater Los Angeles Health Care System David Geffen School of Medicine at UCLA United States

ISBN: (纸本)9789639799172

Falls are currently a leading cause of death from injury in the elderly. The usage of the conventional assistive cane devices is critical in reducing the risk of falls and is relied upon by over 4 million patients in the U.S. While canes provide physical support as well as supplementary sensing feedback to patients, at the same time, these conventional aids also exhibit serious adverse effects that contribute to falls. The falls due to the improper usage of the canes are particularly acute in the elderly and disabled where reduced cognitive capacity accompanied by the burden of managing cane motion leads to increased risk. This paper describes the development of the SmartCane assistive system that encompasses broad engineering challenges that will impact general development of individualized, robust assistive and prosthetic devices. The SmartCane system combines advances in signal processing, embedded computing, and wireless networking technology to provide capabilities for remote monitoring, local signal processing, and real-time feedback on the cane usage. This system aims to reduce risks of injuries and falls by enabling training and guidance of patients in proper usage of assistive devices. Copyright © 2008 ICST.

关键词： Patient monitoring

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Mobile Applications Provisioning Using Bluetooth Wireless Technology

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Journal of Software engineering and Applications 2011年第2期4卷 95-105页

作者： Thomas Djotio Ndie Claude Tangha Tam Sangbong Armstrong Formenah Kufor LIRIMA Management and Security of Network and System Services University of Yaounde I Department of Computer Science National Advanced School of Engineering University of Yaounde I Soft-Tech International Inc

In this paper, we propose a cheap means for propagating mobile application using Bluetooth, a convenient short range wireless technology. Today, one of the main problems about mobile technology is about implementing automatically the software in the multiple and various type of phones devices, irrespective of the phone model (Nokia, Samsung, iPhone, etc.). There are many ways of doing OTA like by SMS. This approach allows providing an http download link by SMS but, we are limited by the maximum size one can have to build an application and send it trough this means. This approach is also expensive because data sources are expensive. Within the context of mobile social networking and proximity marketing, we come up with an original way of provisioning mobile applications using Bluetooth. We use anybody who is already a subscriber of an application to become an ambassador of it. The application is self-replicating and distributing in itself and sending back results. It ethically acts like a virus or a disease. A prototype is built to validate the proposed methodology.

关键词： Mobile Application Application Provisioning Bluetooth Mobile Social Network Application Auto-Replication

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