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Effective operation and performance improvement methods for OMTP BONDI-based mobile Web widget resources

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第10期12卷 787-799页

作者： Jiwoong BANG daewon kim Department of Computer Science Dankook University Department of Multimedia Engineering Dankook University

The Open Mobile Terminal Platform (OMTP) is a global forum made by telecommunications providers to promote user-oriented mobile services and data businesses. Devised by OMTP, BONDI is a browser-based application or a mobile Web run-time platform to help widgets make good use of the functions of mobile devices in a secure way. BONDI enables applications programmed with Web standard technologies such as HTML, JavaScript, CSS, and AJAX to reach the internal functions of mobile devices. Since BONDI, which is not just a simple network application, can reach the internal resources of devices in standard ways, it enables the application and widgets to be developed regardless of the operating system (OS) or platform. Web browser-based widgets are vulnerable to the network environment, and their execution speed can be slowed as the operations of the widgets or applications become heavy. Compared with the native widgets inside the device, however, those Web widgets will be continuously used thanks to the user-friendly simple interface and the faster speed in using Web resources. This study deals with a method to effectively operate and manage the resources of OMTP BONDI Web widget and provides improved results based on running performance evaluation experiments. The experiments were carried out to improve the entire operating time by enhancing the module-loading speed. In this regard, only indispensable modules were allowed to be loaded while the BONDI widget was underway. For this purpose, the widget resource list, which can make the operating speed of the BONDI widget faster, was redefined while a widget cache was employed. In addition, the widget box, a management tool for removed widgets, was devised to store temporarily idle widgets.

关键词： Mobile OMTP BONDI Web Widget Resources

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Stress Analysis of Membrane Flapping-Wing Aerial Vehicle Based on Different Material Models

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Journal of Applied Mathematics and Physics 2014年第12期2卷 1023-1030页

作者： Chunjin Yu daewon kim Yi Zhao Institute of Flight Vehicle Engineering Nanchang Hangkong University Nanchang China Department of Aerospace Engineering Embry-Riddle Aeronautical University Daytona Beach USA

Recent studies of flapping-wing aerial vehicles have been focused on the aerodynamic performance based on linear materials. Little work has been done on structural analysis based on nonlinear material models. A stress analysis is conducted in this study on membrane flapping-wing aerial vehicles using finite element method based on three material models, namely, linear elastic, Mooney-Rivlin non linear, and composite material models. The purpose of this paper is to understand how different types of materials affect the stresses of a flapping-wing. In the finite element simulation, each flapping cycle is divided into twelve stages and the maximum stress is calculated in each stage. The results show that 1) there are two peak stress values in one flapping cycle;one at the beginning stage of down stroke and the other at the beginning of upstroke, 2) maximum stress at the beginning of down stroke is greater than that at the beginning of upstroke, 3) maximum stress based on each material model is different. The composite and the Mooney-Rivlin nonlinear models produce much less stresses compared to the linear material model;and 4) the ratio of downstroke maximum stress and upstroke maximum stress varies with different material models. This research is helpful in answering why insect wings are so impeccable, thus providing a possibility of improving the design of flapping-wing aerial vehicles.

关键词： Flapping-Wing Aerial Vehicle Membrane Wing Stress Analysis

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Lift and Thrust Characteristics of Flapping Wing Aerial Vehicle with Pitching and Flapping Motion

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Journal of Applied Mathematics and Physics 2014年第12期2卷 1031-1038页

Development of flapping wing aerial vehicle (FWAV) has been of interest in the aerospace community with ongoing research into unsteady and low Reynolds number aerodynamics based on the vortex lattice method. Most of the previous research has been about pitching and plunging motion of the FWAV. With pitching and flapping motion of FMAV, people usually study it by experiment, and little work has been done by numerical calculation. In this paper, three-dimension unsteady vortex lattice method is applied to study the lift and thrust of FWAV with pitching and flapping motion. The results show that: 1) Lift is mainly produced during down stroke, however, thrust is produced during both down stroke and upstroke. The lift and thrust produced during down stroke are much more than that produced during upstroke. 2) Lift and thrust increase with the increase of flapping frequency;3) Thrust increases with the increase of flapping amplitude, but the lift decreases with the increase of flapping amplitude;4) Lift and thrust increase with the increase of mean pitching angle, but the effect on lift is much more than on thrust. This research is helpful to understand the flight mechanism of birds, thus improving the design of FWAV simulating birds.

关键词： Flapping Wing Aerial Vehicle Lift Characteristics Thrust Characteristics

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Sn3．5Ag0．75Cu钎料与Au／Ni／Cu焊盘接头老化过程中IMC组织的演变

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现代表面贴装资讯 2007年第2期6卷 42-44页

作者：秦毅李明雨 kim Jongmyung kim daewon 哈尔滨工业大学深圳研究生院 Jeonnam Provincial College

通过SEM（Scanning Electron Microscope）背散射照片和EDX（Energy Dispersive X-Ray Spectroscopy）成分分析研究了无铅钎料Sn3．5Ag0．75Cu与Au／Ni／Cu焊盘接头在老化过程中其界面金属间化合物（IMC）的生长演变过程；在175℃温度... 详细信息

通过SEM（Scanning Electron Microscope）背散射照片和EDX（Energy Dispersive X-Ray Spectroscopy）成分分析研究了无铅钎料Sn3．5Ag0．75Cu与Au／Ni／Cu焊盘接头在老化过程中其界面金属间化合物（IMC）的生长演变过程；在175℃温度条件下老化72h后发现Cu可以穿过Ni层参与形成界面金属间化合物（Au，Ni，Cu）Sn4和（Au，Ni，Cu）6Sn5；基于金属间化合物生长动力学理论计自得该焊点结构中AuSn4生长的活化能为53．78KJ／mol。

关键词：金属间化合物无铅钎料活化能

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Wide speed range for traction motor in braking force of electric braking control system

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Journal of Central South University 2014年第10期21卷 3837-3843页

作者： Young-Choon kim Moon-Taek Cho Division of Mechanical and Automotive Engineering College of EngineeringKongju National University Department of Electrical & Electric Engineering Daewon University College

A vehicle stopping method using an electric brake until a traction motor is stopped is studied. At the moment of vehicle stop, electric brake is changed to control mode where torque is reduced at a low speed. Gradient is controlled by estimating the load torque of motor, thereby traction motor is not rotated after stop. In addition, coasting operation and brake test are performed from normal-opposite operation and start using a small-scale model comprising the inertial load equipment and the power converter. Further, traction motor is made to be equipped with a suspension torque. Pure electric braking that makes traction motor stop by an air brake at the time of stop is also implemented. Constant torque range and constant power range are expanded during braking so that braking force is secured with the electric brakes even in high speed region. Therefore, vehicle reduction effect can be expected by reducing parts related with an air brake which is not used frequently by using a pure electric brake in the M car in wide speed region. Further, maintenance of brake system can be reduced. Besides, ride comfort of passenger in the electric rail car, energy efficiency improvement, and noise reduction effect can be additionally expected. Further, an improved brake method that uses only an electric brake till motor stop is proposed by comparing those in the blending brake that uses an air brake while reducing brake torque at vehicle stop.

关键词： wide speed range electric braking control traction motor

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