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A Routing Protocol for Urban Vehicular Multi-hop Data Delivery

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Chinese Journal of Electronics 2016年第2期25卷 348-356页

作者： CHANG Sang-woo LEE Sang-sun Department of Electronic Engineering Hanyang University

Vehicular ad-hoc network(VANET) has distinctive environments such as highly dynamic topology, frequently disconnected network, hard delay constraints for safety-related application, and various communications environments based on highway or urban traffic scenarios. Therefore, development of a suitable routing protocol that considers these characteristics of VANET should be needed. In this paper we propose the improved distance-based VANET routing protocol in urban traffic environments. We apply approaches to multi-hop broadcast scheme for reliable packet dissemination in the intersection and stable route decision scheme based on the adaptive waiting time. The performance is evaluated under simulation which is implemented with the Manhattan urban traffic model. The results show the improved performance as compared with other protocols.

关键词： Distance-based routing protocol Vehicle-to-vehicle communication Waiting time Urban traffic environments Vehicular ad-hoc network(VANET)

Authentication mechanism for fast handoff in cdma2000-WiBro interworking

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Science China(Information Sciences) 2010年第1期53卷 137-146页

作者： HONG Do Won KIM Je Yoon SHIN Sang Uk Electronics and Telecommunications Research Institute Penta Security Systems Inc. Pukyong National University

In this paper, we propose the authentication mechanism for a handoff in cdma2000-WiBro interworking environment. In the interworking environment, the handoff procedure requires the authentication on MS for the access control and the accounting. In the handoff procedure, it is required to perform the EAP-AKA authentication process with cdma2000-HN (home network) because TN (target network) does not have the information for the authentication about MS. This process has relatively long delay. Therefore, the fast handoff authentication mechanism for reducing the long delay in the handoff procedure is needed. Thus this paper proposes the handoff authentication method of using the reactive context transfer and ticket forwarding method, to provide the fast handoff in cdma2000-WiBro interworking environment. The proposed scheme satisfies security requirements on handoff and has the advantage of low signaling overhead in handoff authentication.

关键词： authentication cdma2000 WiBro interworking handoff

Lightweight design of 45000r/min spindle using full factorial design and extreme vertices design methods

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Journal of Central South University 2011年第1期18卷 153-158页

作者： PARK Seong-jin LEE Choon-man HWANG Young-kug Department of Mechanical Design and Manufacturing Engineering Changwon National University

Factors for determining the spindle size are the shaft diameter, positions of bearing and motor, and entire length of the spindle. Then, it is important to find the assembling of the optimal design variables, which satisfy the stiffimss and rotational speed required to the spindle. A general full factorial design method was used to verify some factors that affect the natural frequency of a spindle. It is verified that the shorter shaft length and bearing span length represent the higher natural frequency, and there are some effects according to the change in the levels of factors. The detailed spindle dimension is determined by applying an EVD method, which can define the optimal bearing position through considering the limiting condition. Based on the estimated regression model, the optimal spindle size and bearing distance that can improve the primary natural frequency are obtained, and the influence of design factors on the natural frequency is also analyzed.

关键词： high-speed spindle extreme vertices design natural frequency lightweight design full factorial design

Efective Object Identification and Association by Varying Coverage Through RFID Power Control

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Journal of Computer Science & Technology 2014年第1期29卷 4-20页

作者： Shung Han Cho Kyung Hoon Kim Sangjin Hong IEEE System LSI Business Samsung Electronics Department of Electrical and Computer Engineering Stony Brook University

This paper presents an effective power scheduling strategy for energy efficient multiple objects identification and association. The proposed method can be utilized in many heterogeneous surveillance systems with visual sensors and RFID （radio-frequency identification） readers where energy efficiency as well as association rate are critical Multiple objects positions and trajectory estimates are used to decide the power level of RFID readers. Several key parameters including the time windows and the distance separations are defined in the method in order to minimize the effects of RFID coverage uncertainty. The power cost model is defined and incorporated into the method to minimize energy consumption and to maximize association performance. The proposed method computes the power cost using the range of the outermost position for possible single association and group associations at every sampling time. An RFID reader is activated with the proper coverage range when the power cost for the current time is lower than the power cost for the next time sample. The simplicity of the power cost model relieves the problematic combinatorial comparisons in multiple object cases. The performance comparison simulation with the minimum and maximum energy consumption shows that the proposed method achieves fast single associations with less energy consumption. Finally, the realistic comparison simulation with the fixed range RFID readers demonstrates that the proposed method outperforms the fixed ranges in terms of single association rate and energy consumption.

关键词： object association RFID power control power scheduling visual sensor collaboration

Analysis and optimization of nitrile butadiene rubber sealing mechanism of ball valve

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中国有色金属学会会刊：英文版 2009年第B09期19卷 220-224页

作者： Young-Chul PARK Department of Mechanical Engineering Dong-A University

An approach for analyzing and optimizing sealing mechanism of ball valve made of nitrile butadiene rubber(NBR) with finite element method was presented. The Mooney-Rivlin hyperelastic material model was chosen to characterize NBR sealing, as it has been recommended in the similar applications. That is, NBR sealing was modeled as incompressible hyperelasticity, as well as the assumption of isotropic flow. The results illustrate the structural pressure and contact pressure on the contact surface, which shows that the NBR sealing mechanism is very suitable for sealing after dimension optimization.

关键词：橡胶密封丁腈橡胶尺寸优化机制球阀有限元方法材料模型各向同性

Structural optimization for ball valve made of CF8M stainless steel

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中国有色金属学会会刊：英文版 2009年第B09期19卷 258-261页

作者： Seung-Gyu KIM Seok-Heum BAEK Young-Chul PARK Department of Mechanical Engineering Dong-A University

The mechanical and chemical properties of CF8M were studied through experiments. An application of CF8M in valve body was analyzed by using finite element method(FEM) to evaluate the structural safety. An optimization containing several variables based on the response surface method(RSM) was conducted to find the optimum dimension of the valve. The results show that using this process can save valve mass as well as the computational expense effectively.

关键词：结构优化球阀不锈钢化学性能有限元法结构安全最佳尺寸 FEM

Torsional vibration analysis of lathe spindle system with unbalanced workpiece

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Journal of Central South University 2011年第1期18卷 171-176页

作者：郭瑞 JANG Sung-Hyun CHOI Young-Hyu School of Mechatronics Changwon National University

For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared *** using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and *** results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining *** the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges.

关键词： unbalanced work piece gravitational unbalance torque torsional vibration spindle system geared transmission

Development of CAD/CAM system and profile measuring device for CNC grinding machine to obtain an optimal grinding speed

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Journal of Central South University 2011年第1期18卷 146-152页

作者： LIM Sang-Heon KIM Jae-Hyun LEE Choon-Man Agency of Promoting Technology Innovation Gyeongnam TechnoparkChangwon 641-465Korea School of Mechatronics Changwon National University

Cam mechanics is one of the most popular devices for generating irregular motions and is widely used in automatic equipment,such as textile machines,internal combustion engines,and other automatic *** order to obtain a positive motion from the follower using a rotating cam,its shape should be correctly designed and *** development of an adequate CAD/CAM system for a cam profile CNC grinding machine is necessary to manufacture high-precision *** purpose of this study is the development of a CAD/CAM system and profile measuring device for a CNC grinding machine to obtain an optimal grinding speed with a constant surface *** types of disk cams were manufactured using the proposed algorithm and procedures to verify effectiveness of the developed CAD/CAM system.

关键词： cam CAD/CAM system CNC grinding machine optimal grinding speed

Science Letters:Human-centered modeling for style-based adaptive games

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第4期10卷 530-534页

作者： Chee-onn WONG Jongin KIM Eunjung HAN Keechul JUNG Human-Centered Interfaces Lab Department of Digital Media Soongsil UniversitySeoul 156743 Korea

This letter proposes a categorization matrix to analyze the playing style of a computer game player for a shooting game genre. Our aim is to use human-centered modeling as a strategy for adaptive games based on entertainment measure to evaluate the playing experience. We utilized a self-organizing map (SOM) to cluster the player's style with the data obtained while playing the game. We further argued that style-based adaptation contributes to higher enjoyment, and this is reflected in our experiment using a supervised multilayered perceptron (MLP) network.

关键词： Player modeling Categorization matrix Adaptive games Human-centered modeling Data clustering