• Journal of Advanced Marine Engineering and Technology
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• v.17 no.1
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• pp.33-44
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• 1993

Active control of a flow field is essential to design efficient parts or elements relating to fluid machineries. The present study is aimed to suggest a new discretization technique of the convection term by renewing the non-conservative equation found in SOLA-VOF into a conservative one. And, as an application, flow characteristics are investigated by adjusting the backward ejecting velocity of 2-D square prism to control the aerodynamic properties. Strouhal number, drag and lift coefficient are compared in terms of various ejecting velocity. Among the results, the transient weak fluctuation of the lift and drag coefficient when the ejecting velocity equals channel inlet velocity is remarkably noticed.

• Journal of Engineering Education Research
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• v.15 no.4
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• pp.48-52
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• 2012

The purpose of this paper is to design and implement the user motion pattern control system for the simulated vehicle. After analyzing the user motion patterns in the system, the patterns are used to control the moving direction of the simulated vehicle such as forward, backward, turn right, turn left etc. The patterns in the system around are sent to the simulated vehicle in real time. In order to execute the suggested user motion pattern control system, the Kinect is used for executing the system. The Kinect recognizes the specified user motion patterns and it transmits the data to the user motion pattern control system. There are nine kinds of the user motion patterns in the system for controlling the simulated vehicle. In addition to this, some sensors are used to detect the condition of the simulated vehicle. GPS is also used to estimate the current location of the simulated vehicle and to obtain the driving information.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.607-612
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• 1993

원심분리기는 용액 속에 있는 물질을 크기와 밀도 및 모양의 다름을 이용하여 용액으로부터 분리, 정제 및 순화하는 과학기계이며 처리량의 규모에 따라 공업용과 실험실용으로 분류된다. 공업용은 처리량이 많은 반면 실험실용은 처리량이 적으나 분리효과가 좋은 특징을 갖으며 회전속도에 의해 저속, 고속 및 초고속의 원심분리기로 나뉘어진다. 초고속 원심분리기는 최초(30년대)에 침전계수의 측정을 목적으로 연구개발을 시작하였다. 이의 용도에서 사용되는 초고속원심기를 분석용 초고속원심기라 부르나 이는 50년대 이후에 점차적으로 기술적 발전을 가져와 미소물질 분리를 위한 분리용 초고속원심기로 변천이 되어 생물학분야 이외에 항공기,선박,고속철도,석유탐지,원자력,섬유공업과 반도체등 여러 분야에 이용이 되고 있다.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.117-123
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• 2005

This paper deals with the finite element model of the monitor fur the simulation of directional free drop tests such as the backward and vertex free drop as well as the associated free-drop experiment. The model was made for an unconditional stable solution fur the explicit integration algorithm. It was found through the comparison between simulation and experimental results that the general behaviors at the time of impact were observed to well correlate with each other in terms of acceleration, displacement, contact force and stress of monitor components.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.242-248
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• 2000

This paper is concerned with the family of parts that generally feature a central hub with radial protrusions. Radial Extrusion is usually used in order to produce complex parts, which is combined with upsetting and/or forward and backward extrusion. Typical parts that fall into this category include cross pieces for universal joints, key-shaft type parts, tube fittings, and differential gears. In this paper, the forming characteristics of radial extrusion combined with forward extrusion is investigated by comparing the punch and mandrel loads. The design factors during radial extrusion combined with forward extrusion are applied to the simulation to see how much those factors have effect on the forming loads. The rigid-plastic FEM is applied to the simulation.

• The KSFM Journal of Fluid Machinery
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• v.2 no.2 s.3
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• pp.46-56
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• 1999

This study is on the performance prediction and design of a sirocco fan. Slip coefficient is very important factor for the performance analysis of a centrifugal-type fan. Because generally used slip coefficient equations of backward curved centrifugal fan are not appropriate for forward curved sirocco fan, in this study a proper slip coefficient equation for a sirocco fan is suggested. Using this equation performance prediction program for sirocco fan is composed of and also included the total noise prediction that include the turbulent noise at the fan inlet and boundary layer noise. A comparison between the values obtained from performance prediction program and experimental values shows that the program predicts the sirocco fan performance in a practical rate.

• Journal of the Korean Society of Safety
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• v.9 no.4
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• pp.49-57
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• 1994

In this paper, a speed controller using a controller is implemented and applied to a DC motor for FA ( Factory Automation ). The objective of this paper treats the analytical and experimental studies on the improvement of control circuit and control method using a SCR-LEONARD circuit for the speed control of DC motor. This system is concerned with stabilization of single input or single output systems, so the plant (SCR-LEONARD+DC motor) is simplified to the first order system. The parameters for the PID controller are obtained by the transient-response tunning method, and this control scheme has a backward-shift operator. The control algorithms (Chopper＋transient response tunning) is used to check the performance of PID Controller through Computer simulations and experiments. The good experiment results show that the direct control of the DC motor applied to industrial field such oi factory automation.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1361-1366
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• 2007

Forging for spring cup of engine valve was investigated in this study. New method is needed to reduce cost and development lead time required to fix forming process of new product, that eventually can provide die, metal flow and forming loads with high confidence level. FEM could provide required detail information that could reduce trial error in advance before the actual production. By using the rigid-plastic finite element simulation, possibilities of improving former research were explored. Results generated by FEM could foresee expected material deformation in advance and made possible new forming process successfully.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.13-19
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• 2007

To find out the optimum design of hydrogen storage and supply tank using Metal Hydride (briefly MH) and to make clear the performance characteristics under various conditions are our research purpose. In order to use the low-temperature exhaust heat, $LaNi_{4.7}Al_{0.3}$ which operates under the low pressure of 1 MPa is chosen, and we measure the basic properties, namely density, specific heat, PCT(Pressure-Concentration-Temperature) characteristics, and effective thermal conductivity. Then, a numerical calculation model of hydrogen storage using MH alloy is suggested and this thermal diffusion equation of model is solved by the backward difference method. This calculation results are compared with the experimental results of the systems which installed 1kg MH alloy and, it is found out that our calculation model can well predict the experimental results. By the experimental using MH alloy, it is recognized that the hydrogen flow rate can control by the step adjustment of brine temperature.

• 한국어정보학회:학술대회논문집
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• 2017.10a
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• pp.201-202
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• 2017

의료정보시스템의 상호운용을 위해 개발된 의료정보 교환 국제 표준인 HL7은 복잡한 구조와 문법으로 인해 컴퓨터 소프트웨어로 관리되고 있다. 현재 개발되고 있는 HL7 인터페이스 소프트웨어에서는 다양한 버전 간 호환이 되지 않아 의료정보시스템에서 버전 상호 간의 호환을 위해 변환 소프트웨어 모듈을 개발하여 사용한다. 그러나 다양한 버전(V2.1~V2.8)의 HL7 메시지 간 상호 변환을 위해 소프트웨어 모듈을 모두 개발하는 것은 많은 시간과 막대한 비용 및 노력이 필요한 비효율적인 방법이다. 따라서 본 연구에서는 HL7 버전 호환성 정의에 기반을 두어 버전별 상호변환이 가능한 HL7 파서(Parser)를 설계하고, 객체 지향적 구조에 기반을 두어 하위 버전과의 호환(Backward Compatibility)뿐만 아니라 상위 버전과 호환(Forward Compatibility) 가능한 파서를 제안한다. 또한, 버전 간 변환 실험을 통해 효용성을 검증하였다.