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Resonance Raman spectroscopy in Si and C ion-implanted double-wall carbon nanotubes

Physical Review B 2009年第15期80卷 155452-155452页

作者： G. D. Saraiva A. G. Souza Filho G. Braunstein E. B. Barros J. Mendes Filho E. C. Moreira S. B. Fagan D. L. Baptista Y. A. Kim H. Muramatsu M. Endo M. S. Dresselhaus Universidade Estadual do Ceará 60740-000 Fortaleza CE Brazil Departamento de Física Universidade Federal do Ceará Caixa Postal 6030 CEP 60455-900 Fortaleza CE Brazil Micron Technology Inc. 9600 Godwin Drive Manassas Virginia 20110 USA Universidade Federal do Pampa (UNIPAMPA) Campus Bagé 96412-420 Bagé RS Brazil Centro Universitário Franciscano–UNIFRA 97010-032 Santa Maria RS Brazil Departamento de Física Universidade Federal do Rio Grande do Sul 91501-970 Porto Alegre RS Brazil Faculty of Engineering Shinshu University 4-17-1 Wakasato Nagano-shi 380-8553 Japan Department of Physics and Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge Massachusetts 02139-4307 USA

The effect of 170 keV Si and 100 keV C ion bombardment on the structure and properties of highly pure, double-wall carbon nanotubes has been investigated using resonance Raman spectroscopy. The implantations were performed at room temperature with ion doses ranging between 1×1013 ions/cm2 and 1×1015 ions/cm2. As expected, the Si irradiation created more disorder than the C irradiation for the same ion fluence. For both species, as the ion-implantation fluence increased, the D-band intensity increased, while the G-band intensity decreased, indicating increased lattice disorder, in analogous form to other forms of graphite and other nanotube types. The frequency of the G band decreased with increasing dose, reflecting a softening of the phonon mode due to lattice defects. With increasing ion fluence, the radial breathing modes (RBMs) of the outer tubes (either semiconducting or metallic) disappeared before the respective RBM bands from the inner tubes, suggesting that the outer nanotubes are more affected than the inner nanotubes by the ion irradiation. After Si ion bombardment to a dose of 1×1015 ions/cm2, the Raman spectrum resembled that of highly disordered graphite, indicating that the lattice structures of the inner and outer nanotubes were almost completely destroyed. However, laser annealing partially restored the crystalline structure of the nanotubes, as evidenced by the re-emergence of the G and RBM bands and the significant attenuation of the D band in the Raman spectrum.

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On a web-graph-based micronetwork architecture for SoCs

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International Journal of computers and Applications 2008年第1期30卷 1-8页

作者： Wang, L. Piao, S. Jiang, Y. Zhang, L. Department of Computer Science Harbin Institute of Technology Harbin Heilongjiang Province China Department of Electrical and Computer Engineering University of Nevada Las Vegas NV 89154 United States Faculty of Engineering and Applied Science Memorial University of Newfoundland St. John's NL A1B 3X5 Canada

The Network-on-Chip (NoC) concept has been identified as an attractive solution to the ever-increasing interconnect problem in complex System-on-Chip (SoC) designs. In this paper, we propose a highly scalable topology structure for NoC designs based on the web graph. This topology, named as Spidernet, is compared favourably to other five popular NoC topologies, including mesh, torus, fat tree, octagon, and spidergon in terms of node degree, network diameter, connection degree, average most short-circuit path, and average shortest wire length. We further propose a 2D layout design for Spidernet, and experiment results have confirmed its superiority over layouts derived from the above five competing topologies.

关键词： Network architecture

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A rule-based approach for availability of Web service

A rule-based approach for availability of Web service

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IEEE International Conference on Web Services, ICWS 2008

作者： Liang, Qianhui Althea Lam, Herman Narupiyakul, Lalita Hung, Patrick C.K. School of Information Systems Singapore Management University Singapore Singapore Department of Electrical and Computer Engineering University of Florida United States Faculty of Business and IT University of Ontario Institute of Technology Canada

ISBN: (纸本)9780769533100

Sustainable success of service oriented applications relies on capabilities to manage possible service failures. To substitute a failed service with some other equivalent service is unavoidable in recovering a suspended application due to failure of a constituent service. In this paper, we report a rule-based approach to Web service substitution in order to secure availability of services. Availability provides delivery assurance for each Web service so that Simple Object Access Protocol (SOAP) messages cannot be lost undetectably, especially in a Web service composition. The rides are written in Semantic Web Rule Language. The rules are a formal representation of a categorization-based scheme to identify exchangeable Web services. This scheme not only tackles the issue of heterogeneity of domain ontology in describing the Web services, it also adapts itself by learning newly discovered ontology instances. A technical framework of Web service substitution using rule based deduction is demonstrated. Experiments on service substitution based on the proposed framework achieve a best precision of 85%. © 2008 IEEE.

关键词： Web services

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A 5 GHz BiCMOS I/Q VCO with 360 variable phase outputs using the vector sum method

A 5 GHz BiCMOS I/Q VCO with 360 variable phase outputs using...

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2008 IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2008

作者： Opperman, Tjaart A.K. Sinha, Saurabh University of Pretoria Dept. of Electrical Electronic and Computer Engineering Carl and Emily Fuchs Institute for Microelectronics Corner of University Road and Lynnwood Road Pretoria 0002 South Africa Department of Electrical Electronic and Computer Engineering Faculty of Engineering Built Environment and Information Technology School of Engineering Pretoria 0002 South Africa

ISBN: (纸本)9781424426447

A 5 GHz In-phase/Quadrature (I/Q) voltage controlled oscillator (VCO) with multiple independently tunable phase outputs is presented. The VCO is realized using an LC oscillator with a ring structure and has a tuning range of between 4.6 and 5.3 GHz. The variable phase shift is achieved by varying the amplitudes of the two quadrature signals independently and then combining these signals together. Using multiple Gilbert cells as variable gain amplifiers (VGAs), multiple tunable phase outputs are achieved using only a single coupled I/Q VCO. The entire circuit is designed using a 3.3V SiGe BiCMOS process. This VCO can be used as a phase shifter in adaptive phase array antenna systems, whereby the beam is formed by controlling the phase of individual antenna elements. © 2008 IEEE.

关键词： Antenna phased arrays

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Tracking and Disturbance Rejection of Extended Constant Signals with Unknown Disturbance Structure Using MPC

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SICE Journal of Control, Measurement, and System Integration 2008年第2期1卷 82-91页

作者： Edward J. Davison Ruth Milman Systems Control Group Dept. of Electrical and Computer Engineering University of Toronto Faculty of Engineering and Applied Science University of Ontario Institute of Technology

This paper considers the Model Predictive Control (MPC) set point tracking/regulation problem for a discrete LTI system, which is subject to a class of unbounded disturbances/tracking signals called extended constant signals of unknown structure. Examples of disturbances which belong to this class include constant disturbances as well as unbounded signals such as w[k]=√k and log (k), k=1,2,3,…. A discussion re the choice of window size for MPC is also made; in particular, it is shown that the window size must be larger than a certain lower bound, which can be easily determined, in order to guarantee closed loop stability in MPC control. The main contribution is a formulation of the system's plant equations under which, for output regulation, no knowledge of the structure or magnitude of disturbances is needed in order to achieve set point regulation for this class of extended constant signals. The result is of interest since it also implies that no disturbance observer is necessary in order to solve the set point tracking/regulation problem when full-state feedback is available. The results are experimentally verified.

关键词： model predictive control disturbance rejection extended constant signals output feedback/regulation observers tracking

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Novel Regenerative Braking Control of Electric Power Assisted Wheelchair for Optimal Velocity Driving on Downhill Road

Novel Regenerative Braking Control of Electric Power Assiste...

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10th IEEE International Workshop on Advanced Motion Control (AMC'08), vol.2

作者： Hirokazu Seki Kenji Ishihara Susumu Tadakuma Department of Electrical Electronics and Computer Engineering Faculty of Engineering Chiba Institute of Technology Narashino Chiba Japan

This paper describes a novel regenerative braking control scheme of electric power assisted wheelchairs for optimal velocity driving on downhill roads. "Electric power assisted wheelchair" which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people, however, it has no braking system to suppress the wheelchair's velocity and brings the dangerous and fearful driving especially on downhill roads. Therefore this paper proposes a novel safety and efficient driving control scheme based on the regenerative braking system. This study applies the regenerative braking system with the step-up chopper circuit serially connecting two motors and realizes the velocity feedback control with the variable duty ratio so that it tracks the optimal velocity based on Minimum Jerk Model. In addition, the dynamic braking system is also applied at the low speed range instead of the regenerative brake in order to suppress the acceleration. Some driving experiments on the practical downhill roads show the effectiveness of the proposed control system.

关键词： Electric power assisted wheelchair Driving control Regenerative braking control Minimum Jerk Model Dynamic brake Ride quality

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Robust Vision-based Autonomous Navigation against Environment Changes

Robust Vision-based Autonomous Navigation against Environmen...

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2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, Pages 526-1042

作者： Jungho Kim Yunsu Bok In So Kweon Department of Electrical Engineering and Computer Science Korea Advanced Institute of Science and Technology South Korea Faculty of Electrical Engineering and Computer Science Korea Advanced Institute of Science and Technology Daejeon South Korea

ISBN: (纸本)9781424420575

Recently, many vision-based navigation methods have been introduced as an intelligent robot application. However, many of these methods mainly focus on finding an image in the database corresponding to a query image. Thus, if the environment changes, for example, objects moving in the environment, a robot is unlikely to find consistent corresponding points with one of the database images. To handle these problems, we propose a novel motion-based navigation method in contrast with appearance-based approaches. This algorithm is based on motion estimation by a camera to plan the next movement of a robot and robust feature matching to recognize home and destination locations. Experimental results demonstrate the capability of the vision-based autonomous navigation against environment changes.

关键词： Robots Navigation Robot kinematics Cameras Three dimensional displays Robot vision systems Feature extraction

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Maximization of system lifetime in body sensor networks

Maximization of system lifetime in body sensor networks

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International Conference on electrical and computer engineering (ICECE)

作者： Md. Nazrul Islam Mondal Kazi Mohiuddin Ahmed Department of Computer Science & Engineering Faculty of Electrical & Computer Engineering Rajshahi University of Engineering and Technology Bangladesh Department of Telecommunications School of Engineering & Technology Asian Institute of Technology Bangkok Thailand

In this paper, the target is to reduce the energy consumption in the body sensor network as well as maximize the system lifetime of sensor nodes when they will make communication among body sensors and personal communication unit. The best compression technique like LPC is selected for energy saving based on some calculations. Formulation of a linear programming problem where is to maximize the system lifetime which is equivalent to the time until the first node runs out of battery. Maximum system lifetimes are calculated by MATLAB optimization technique using and without using efficient compression algorithm like LPC in various environments. The results show that maximum system lifetimes calculated in different scenarios using efficient compression technique like LPC is better than without using compression technique.

关键词： Body sensor networks Linear predictive coding Power engineering and energy Linear programming Batteries Wireless sensor networks computer networks Energy consumption Sensor systems Compression algorithms

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An Alpha-wave-based binaural beat sound control system using fuzzy logic and autoregressive forecasting model

An Alpha-wave-based binaural beat sound control system using...

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SICE Annual Conference

作者： Sittapong Settapat Michiko Ohkura Department of Electrical Engineering and Computer Science Graduate School of Engineering Shibaura Institute of Technology Tokyo Japan Faculty of Engineering Shibaura Institute of Technology Tokyo Japan

ISBN: (纸本)9784907764302

We are developing a new real-time control system for customizing auditory stimulus (the binaural beat sound) by judging user alpha waves to entrain a userpsilas feeling in the most relaxed way. Since brainwave activity provides the necessary predictive information for arousal states, we use an autoregressive forecasting model to estimate the frequency response series of the alpha frequency bands and the inverted-U concept to determine the userpsilas arousal state. A fuzzy logic controller is also employed to regulate the binaural beat control signal on a forecasting error signal. Our system allows comfortable user self-relaxation. The results of experiments confirm the constructed systempsilas effectiveness and necessity.

关键词： Alpha Wave Binaural Beat Biofeedback Fuzzy Logic Autoregressive Model Fuzzy logic autoregressive processes Psychology Biofeedback Beat Frequency bands fuzzy logic controller control systems Sound control Arousal

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Design of Linearly Tapered Slot-line Antenna's Array for Quasi-terahertz Molecular Spectroscopy

Design of Linearly Tapered Slot-line Antenna's Array for Qua...

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European Conference on Microwave

作者： Zbynek Lukes Viktor Otevrel Jaroslav Lacik Zbynek Raida Institute of Radioelectronics Faculty of Electrical Engineering and Computer Science Brno University of Technology Brno Czech Republic

This presented paper deals with the novel design of the Linearly Tapered Slot-line Antenna's (LTSA) array for the Quasi-terahertz Molecular Spectroscopy application. Antenna array was designed for frequency range from 50 GHz to 600 GHz. The antenna is placed on a low lost dielectrically substrate Cuclad 217. The numerical model was analyzed in a EM solver CST Microwave Studio. After basic design, the antenna was optimized by own novel modification of SPC-PNX real-coded genetic algorithm. The wideband global optimization by SPC-PNX genetic algorithm of the broadband antenna for the mm-Band can be interpreted as original results.

关键词： Linear antenna arrays Slot antennas Spectroscopy Broadband antennas Dielectric substrates Genetic algorithms Antenna arrays Frequency Numerical models Algorithm design and analysis

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