• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.945-948
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• 2005

Mobile computing devices are becoming increasingly prevalent in a huge range of physical area, offering a considerable market opportunity. The focus of this paper is on the development of a platform of fault diagnosis system integrating with personal digital assistant (PDA). An improvement of induction machine rotor fault diagnosis based on AI algorithms approach is presented. This network system consists of two parts; condition monitoring and fault diagnosis by using Artificial Intelligence algorithm. LabVIEW allows easy interaction between acquisition instrumentation and operators. Also it can easily integrate AI algorithm. This paper presents a development environment fur intelligent application for PDA. The introduced configuration is a LabVIEW application in PDA module toolkit which is LabVIEW software.

• Journal of Ocean Engineering and Technology
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• v.25 no.1
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• pp.8-13
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• 2011

A compact array system of small buoys is used for wave energy extraction. To evaluate the performance of this system, hydrodynamic analysis is carried out in regular waves using the higher order boundary element method. The motion response of each buoy is calculated considering hydrodynamic interactions caused by other buoys. The effect of energy extraction device is modeled as a linear damping load. The efficiencies of energy conversion are compared using the various sizes and arrangements of the array system and the damping coefficients for energy extraction. The increase in size or the packing ratio of the system gives better efficiency. However, the wave condition and the cost for the system should be considered to optimize performance from the perspective of engineering and economics. The proposed nondimensionalized damping coefficient for energy extraction is 0.1~0.5.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1180-1183
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• 2009

최근 온라인 환경에서 다양한 컨텐츠들이 의사소통의 매개체로 활용되고 있다. 하지만 많은 사용자들은 다양한 형태로 되어있는 정보를 공유, 전달하기 위해 기존 주로 사용되는 의사소통 방법인 문자, 음성으로 변환해야하는 불편함을 겪고 있다. 본 고에서는 온라인 환경에서 사용자들간의 의사소통 방법으로써 원하는 정보를 쉽게 전송하는 방법을 제안한다. 제안된 방법(Information-Picker)은 사용자가 타인에게 전송하려는 정보를 정해진 표식으로 지정하거나 종이에 쓰고, 근접 센서를 통해 사용자가 전송의사를 입력하면, 그 내용을 이미지 센서를 통해 입력 받아 적합한 정보 형태로 변환하여, 타인에게 전송하는 방식이다. Information- picker 는 온라인 환경에서 사용자들간의 의사소통에 있어서 방법의 폭을 넓히는 측면뿐만 아니라, 입력하려는 정보를 센서에 근접시키는 직관적인 인테페이스를 제공하여 사용자로 하여금 쉽고 폭 넓은 의사소통의 편의를 제공할 수 있으며, 특히 현 상황에서의 온라인 사용자들간의 의사전달의 한계를 개선하고, 더욱 풍부한 의도 표현 수단을 제공 할 수 있다.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.180-187
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• 1998

The stability and theoretical performance limits of the feedback controlled force reflecting haptic manipulator have been discussed. All the virtual environment which interact physically with the haptic system have its own stable performance limit. Three different realization of the interfaces have been compared using the driving point admittance. The haptic system which is separated from the human hand or finger is superior to its stable interaction provided that there is a means to apply a direct damping between the haptic manipulator and the human finger Electro-magnetic force is used for its digital implementation of the simple separated type haptic device. The stable limits of a virtual wall is calculated and experimental results show that there is performance limits in this implementation.

• Journal of the Korean Institute of Navigation
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• v.24 no.3
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• pp.133-140
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• 2000

The paper deals with the implementation of prototype Ship Simulator system (VRSS) by Virtual Reality techniques with Head Mounted Display (HMD) device. The prototype VRSS was consists of PC-based human sensors, object oriented operating system. In addition, two kinds of databases arranged from Head Related Transfer Functions and 3D object models were used to create 3D sea sound, and to construct virtual world, respectively. Using the prototype system, we carried out some simulation tests for the overtaking situation to prevent collisions at sea, and discussed on the usability of the system. As results from simulations, the prototype VRSS can provide multisensory and interactive display environment. The results gave rise to the user interaction with 3D objects that give realistic reproduction of navigational environments under a given scenario. Thus, we found that the prototype VRSS should be one of the next-generation ship simulation system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.5
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• pp.303-306
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• 2014

In this paper, by using a dual frequency liquid crystal material, we propose a liquid crystal device with a fast response characteristics. The dual frequency liquid crystal material has a positive dielectric anisotropy value at a low frequency. With a high frequency, the dielectric anisotropy becomes negative. Therefore, the relaxation process is governed by not only the elastic deformation, but also the dielectric interaction. The measured decay time and rise time were 0.88 ms and 0.33 ms, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.594-597
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• 1995

A hand controller in teleoperation is a man-machine interface device that provides real-time interaction between a human operator at control site and a slave manipulator at remote site. In this paper, we examine the design issure related to various types of hand controllers in use. Emphasis is placed on bilateral hand controllers and their design parameters. We describe the design of a new 6 degree-of-freedom universal force-reflecting hand controller to control a remote Schilling Titan manipulator. This hand controller allows the operstor to maintain spatial corresponence in remote manipulative operation and fell a sense of contact with the environment. Finally, we demonstrate the graphic simulation of the hand controller to verify its design characteristics.

• The Journal of the Acoustical Society of Korea
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• v.18 no.5
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• pp.28-34
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• 1999

The effects of the viscosity of an adjacent viscous fluid on the characteristics of the elastic waves have been studied theoretically and experimentally. Expressions for the wave speed and attenuation of the elastic waves of transverse motion, such as the torsional wave propagating in a circular cylinder and the Love wave in a layered half-space solid, have been obtained as functions of the viscosity and mass density of the fluid by exact and asymptotic analyses. The theoretical results have been compared with experimental observations, and it has been demonstrated that a device described herein can be used as a sensor for measuring the viscosity of a fluid with a known mass density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.131-132
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• 2006

We experimentally demonstrated the synthesis of silicon nanoparticles by using high-density ablation plasma prepared by the interaction of an intense pulsed light-ion beam (LIB) with a target. known as the intense pulsed ion beam evaporation (IBE) method. Light emission was obtained from the silicon nanoparticles. It was determined that the ambient gas reaction is very important and useful method to obtain the photoluminescence from the silicon nanoparticles.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.84-88
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• 2005

Eye gaze positions evaluation on computer screen uses the human eye as an input device for computer systems is that it gives low resolution. We proposes a method to determine the eye gaze positions on the screen by using two-eye displacements as the information for mapping, and the perspective projection is applied to map the displacements to a position on a computer screen. The experiments were performed on 20 persons and a 17-inch monitor is used with the screen resolution of 1024x768 pixels. Gaze detection error was 3.18 cm (RMS error), with screen is divided into 5x8 and 7x10 positions on a 17-inch monitor. The results showed 100% and 96% correction, respectively.