• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.961-966
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• 2001

Micro fans of randomly swept-blades were designed to provide C.P.U. in a personal computer with effective cooling in a very quiet mode. The proto--type axial micro-fans machined by a laser sintering machine were tested against manufactured products by comparing the performance and overall sound pressure level with spectral measurements in an environment suggested by ASHRAE and ANSI standards. The predicted OSPLs and directivity patterns of fans by iDesignFan software were in good agreements with measured data. The newly introduced fans of randomly swept-blades were proved to provide a very promising mode of low noise at small loading conditions.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.19-24
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• 1992

Real-time mobile robot controllers usually have been designed with an emphasis on control theory ignoring the importance of system integration. This paper demonstrates that useful mobile robots require a real time controller with a wide range of capabilities in addition to control theory. These capabilities include: path-planning, position estimation, path tracking control and wheel control. An architectural framework supporting these capabilities has been designed and implemented. Using this frame work, individual modules such as a path planner, a path tracking controller, position estimators, wheel controllers and other cruical elements have been successfully integrated into the control system for the LCAR robot which was developed as a proto-type mobile robot in our laboratory. The context of the research, the architecture, its implementation and performance results from experiments are discussed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.10a
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• pp.186-192
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• 1993

Proto-type seismic isolation rubber bearings are investigated through nonlinear hyperelasticity finite elements using the ANSYS general purpose structural analysis code. The purpose of the analysis was to determine the maximum horizontal strain range which can be obtained with a 250KN hydraulic actuator. A Mooney-Rivlin strain energy density function was used as a constitutive law for rubber. The results are compared with the test data available in the literature and found to in good agreement only in the higy strain range. The analysis results can be used with conservatism to predict the necessary force required to a specified displacement such as the purpose of this analysis. However, more precise constitutive model will be required to simulate the bearing behavior with accuracy in the mid-range strain.

• Journal of the Korean Magnetics Society
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• v.6 no.4
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• pp.258-263
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• 1996

Air gap flux density and d, q axis inductances of the Interior Permanent Magnet Synchronous Motor obtained by equivalent magnetic circuit method are compensated using results from Finite Element Method. For optimal design, the efficiency of the motor is taken as the objective function, and Genetic Algorithm finds the value of design parameters which maximize the objective function. The result of optimal designed motor is examined by comparison with proto-type motor.

• Nuclear Engineering and Technology
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• v.27 no.6
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• pp.894-897
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• 1995

원자력 발전소의 안전계통은 요구된 신뢰도를 확보하기 위하여 각 트립 변수(공정계통 및 핵관련 총11개)회로의 센서 및 트립로직으로 구성된 각자의 채널에 대하여 주기적으로 운전중에 운전원에 의해 수동으로 수행하므로 안전계통에 대한 신뢰도를 화보하고 있다. 안전계통에 대한 시험자동화는 컴퓨터에 의해 시험 신호의 발생과 시험 결과의 표시 및 기록이 자동적으로 프로그램에 의해서 수행되는 것을 의미하며, 시험 자동화에 의해 주기 시험에 따른 시험시간 단축과 운전원의 심리적 부담을 경감하여 운전원에 의한 인적 실수 방지 및 계통 신뢰도 향상에 기여하는 것은 물론 계통을 단순화하고 기기경비의 절감 효과를 가져온다. 현재 기존 중수로 발전소는 직접 시험 방식에 의해 모의 신호를 시험 대상 채널의 센서부분에 보내어 안전 계통을 시험하여 해당 루프에 대한 건전성을 점검하고 있는데, 이 방식은 시험회로가 복잡하여 이로인한 기기의 설치 경비 상승, 유지 보수의 부담 증가 및 운전원의 주기 시험에 대한부담감으로 인적 실수를 유발하는등 계통 신뢰도 저하의 문제점이 지적되어 개선이 요구된다.

• Tribology and Lubricants
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• v.24 no.2
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• pp.82-89
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• 2008

The purpose of this study is to develop the proto type sensor installed inside an oil filter in order to detect oil deterioration level. The sensor is made up with two concentric cylinders with constant gap in between and a filter element inside the central area. The size will be designed as similar as real oil filters. The sensor will be tested on a test rig, which is circulating engine oil, with the same size of an oil filter adapting housing as real engines'. It will be measured the capacitance of a sample engine oil, then be able to be gotten the dielectric constant. The changes in the dielectric constant could be correlated with the engine oil deterioration level if the sensor development would be completed. In this paper, it will be shown the test results carrying out under variable temperature conditions at atmosphere pressure.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.538-540
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• 1997

A new dual half bridge induction heating cooker circuit with multiple loads is proposed for reducing the acoustics noise which is caused by the difference between operating frequencies q adjacent loads. This circuit has minimum loss due to the zero voltage switching characteristic. According to the mode analysis of the proposed circuit, we explain the operation of the dual half bridge induction heating cooker circuit The proto-type circuit with 2.8kW power consumption is builted and tested to verify the operation q the proposed circuit.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.2
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• pp.83-83
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• 1996

Recently, for enhanced productivity the induction of CAD/CAM is vigorous. Most of high-level CAD/CAM systems produce powerful faculties. But it is very expensive to purchase the system in small and difficult to be operated by non-experienced workers effectively. Then the resonable CAM system for these is needed. In this study we developed a proto-type of the CAM system for CNC lathe connecting with personal computer. This system is configured with interactive menu windows for easy control of CNC lathe. And the system supports tool path generation for cutting conditions of workpiece. The performance of this system is satisfactory.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.2
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• pp.15-23
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• 1996

Recently, for enhanced productivity the induction of CAD/CAM is vigorous. Most of high-level CAD/CAM systems produce powerful faculties. But it is very expensive to purchase the system in small and difficult to be operated by non-experienced workers effectively. Then the resonable CAM system for these is needed. In this study we developed a proto-type of the CAM system for CNC lathe connecting with personal computer. This system is configured with interactive menu windows for easy control of CNC lathe. And the system supports tool path generation for cutting conditions of workpiece. The performance of this system is satisfactory.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.57-57
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• 2010

Sb(111) is a spin textured surface due to the strong spin-orbit coupling, often viewed as a proto-type topological insulator. We used scanning tunneling microscopy (STM) to characterize various Mn-induced subsurface defects existing at the surface of Mn-doped Sb at 50 K. Our STM images show that every defect exhibits 3-fold symmetry with a single rotational orientation and can be categorized by their shapes and sizes. We found more than 10 types of subsurface defects with distinctive orders, which allows the resolution of the vertical positions of the magnetic dopants lying more than 10 layers down from the surface. We will discuss about our findings in comparison with theoretical results.