• 한국정밀공학회지
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• 제21권1호
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• pp.94-100
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• 2004

Most power steering systems obtain the power by a hydraulic mechanism. Therefore, it consumes more energy because the oil power should be sustained all the times. Recently, to solve this problem the electric power system has been developed and become widely equipped in passenger vehicles. In this research the simulation integration technique for an electric power steering system with MATLAB/SIMULINK and a full vehicle model with ADAMS has been developed. A full vehicle model interacted with electronic control unit algorithm is concurrently simulated with an impulsive steering wheel torque input. The dynamic responses of vehicle chassis and steering system are evaluated. This integrated method allows engineers to reduce the prototype testing cost and to shorten the developing period.

• 한국정밀공학회지
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• 제23권6호
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• pp.72-80
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• 2006

Electric Power Steering (EPS) mechanism has become widely equipped in passenger vehicle due to the increasing environmental concerns and higher fuel efficiency. This paper describes the development of concurrent simulation technique and simulation integration technique of EPS control system with a dynamic vehicle system. A full vehicle model interacting with EPS control algorithm was concurrently simulated on a single bump road condition. The dynamic responses of vehicle chassis and steering system resulting from road surface impact were evaluated and compared with proving ground experimental data. The comparisons show reasonable agreement on tie-rod load, rack displacement, steering wheel torque and tire center acceleration. This concurrent simulation capability was employed fur EPS performance evaluation and calibration as well as for vehicle handling performance integration and synthesis.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.351-354
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• 2003

A new milling machine was designed and manufactured for underwater cutting of rotary specimen racks(RSR) used in the Korea Research Reactor. To cut out intermediate level radioactive stainless steel parts from RSR effectively and safely, the machine was designed to be operated in four directions of X, Y, Z axes and a rotation upon Z axis. The stress and displacement of main frame were simulated by using a structural analysis tool(Design Space) and the pressure of clamping device was evaluated.

• 한국자동차공학회논문집
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• 제12권1호
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• pp.162-167
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• 2004

In this research the Co-simulation technique for an electric power steering system with MATLAB/SIMULINK and a full vehicle model with ADAMS has been developed. The dynamic responses of vehicle chassis and steering system are evaluated. Then, a full vehicle model interacted with EPS control is concurrently simulated with an impulsive steering wheel torque input to analyze the stability of 'free control' or hands free motion for Sports Utility Vehicle. This integrated method allows engineers to reduce the prototype testing cost and to shorten the developing period.

• International Journal of Control, Automation, and Systems
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• 제4권6호
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• pp.748-755
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• 2006

In this paper, a trade-off design and fabrication of IPMC(Ionic Polymer Metal Composites) as an actuator for a flapping device have been described. Experiments for the internal solvent loss of IPMCs have been conducted for various combinations of cation and solvent in order to find out the best combination of cation and solvent for minimal solvent loss and higher actuation force. From the experiments, it was found that IPMCs with heavy water as their solvent could operate longer. Relations between length/thickness and tip force of IPMCs were also quantitatively identified for the actuator design from the tip force measurement of 200, 400, 640, and $800{\mu}m$ thick IPMCs. All IPMCs thicker than $200{\mu}m$ were processed by casting $Nafion^{TM}$ solution. The shorter and thicker IPMCs tended to generate higher actuation force but lower actuation displacement. To improve surface conductivity and to minimize solvent evaporation due to electrically heated electrodes, gold was sputtered on both surfaces of the cast IPMCs by the Physical Vapor Deposition(PVD) process. For amplification of a short IPMC's small actuation displacement to a large flapping motion, a rack-and-pinion type hinge was used in the flapping device. An insect wing was attached to the IPMC flapping mechanism for its flapping test. In this test, the wing flapping device using the $800{\mu}m$ thick IPMC. could create around $10^{\circ}{\sim}85^{\circ}$ flapping angles and $0.5{\sim}15Hz$ flapping frequencies by applying $3{\sim|}4V$.

• 대한기계학회논문집A
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• 제27권3호
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• pp.372-380
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• 2003

Impact tests were conducted to study the effect of angle ply and metal laminate on impact damage characteristics of Fiber Metal laminates (FML). Impact tests were conducted using drop weight impact machine and damage behavior were analyzed by comparing with load-displacement curve and surface observation and microscopic observation of cross sections. The effect of angle ply on impact characteristics of FML are influenced by property of metal laminate. i.e., when the metal laminate is not enough to strong to prevent fiber debonding, Angle ply FML is superior to singly oriented ply (SOP) FML because angle ply enhance the stiffness by fiber supports and prevent (rack propagation. However, when the metal laminate is enough to strong to prevent fiber debonding, SOP FML is superior to Angle ply FML because the fiber of lower ply in Angle ply FML are more stressed than that of SOP FML.

• Structural Engineering and Mechanics
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• 제83권6호
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• pp.745-756
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• 2022

This study aims to determine the cause of the load resistance loss in storage racks that can be attributed to external forces such as earthquakes and to improve safety by developing reinforcement systems that can prevent load resistance loss. To this end, a static cyclic loading test was performed on pallet racks commonly used in logistics warehouses. The test results indicated that a pallet rack exposed to an external force loses more than 50% of its load resistance owing to the damage caused to column-beam joints. Three reinforcement systems were developed for preventing load resistance loss in storage racks exposed to an external force and for performing differentiated target functions: column reinforcement device, seismic damper, and viscoelastic damper. Shake table testing was performed to evaluate the earthquake response and verify the performance of these reinforcement systems. The results confirmed that, the maximum displacement, which causes the loss of load resistance and the permanent deformation of racks under external force, is reduced using the developed reinforcement devices. Thus, the appropriate selection of the developed reinforcement devices by users can help secure the safety of the storage racks.

• 한국산학기술학회논문지
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• 제14권4호
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• pp.1555-1560
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• 2013

칼럼 타입의 전동조향장치(MDPS) 시스템은 차량 안전성과 연료 효율 향상을 보장하기에 승용차에 보편적으로 장착하고 있다. 시스템 해석과 제어기 개발을 위해서는 보통 Mechanical Simulation사에서 제작한 CarSim 프로그램과 매트랩 시뮬링크의 두 프로그램을 이용하여 제어 알고리즘과 차량 모델이 결합되어 하나의 시스템처럼 동시에 동작하도록 시뮬레이션을 수행한다. 매트랩 시뮬링크의 MDPS 제어 시스템과 완전 차량 모델의 동시시뮬레이션 기술개발에 대한 구체적이 방법이 소개된 적이 없기에 본 연구에서 상세히 소개하기로 한다. 본 연구에서는 사인 파형의 조향핸들입력을 이용한 시뮬레이션 결과가 보여 지고 실험결과와 잘 비교되었다. 이러한 동시시뮬레이션 기술은 차량의 핸들링 성능 평가나 CMDPS 평가 수행 및 로직 튜닝을 위해 효과적으로 사용될 수 있다.

• 대한정형외과학회지
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• 제56권2호
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• pp.150-156
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• 2021

목적: 제5 중족골 기저부 골절의 위치와 전위, 관절 침범, 분쇄 등의 특징이 조기 체중부하 치료의 결과에 어떤 영향을 미치는지 알아보고자 하였다. 대상 및 방법: 2013년 1월부터 2017년 7월까지 인제대학교 부산백병원에 내원하여 제5 중족골 기저부 제1, 2 구역 골절로 진단 받은 총 34명의 34예를 대상으로 하였다. 평균 추시 기간은 13개월(6-15개월)이었다. 동 기간 동안 수술적 치료를 시행한 경우는 없었고 1명의 경우 추시 기간 중 이전 골절 부위와 다른 부위의 재골절로 제외되었으며 총 33예 모두 보존적 치료를 시행하였다. 족부의 전후면, 측면 및 경사 방사선 촬영 및 컴퓨터 단층 촬영을 시행하여 골절의 위치와 전위, 관절 침범, 분쇄의 정도를 평가하였다. 33명의 모든 환자에게 있어서 수상 직후부터 단하지 석고고정 혹은 탈착 가능한 부츠형 보조기를 선택하여 착용 후 통증이 허용되는 범위 내에서 부분적인 체중부하를 허용한 뒤 통증이 소실되면 일반 신발 또는 수술 후 신발을 착용 후 전 체중부하를 시행하게 하였다. 임상적 결과로 최종 추시 시에 American Orthopedic Foot and Ankle Society (AOFAS) score를 평가하였다. 외래 추시 시 족부의 단순 방사선 촬영을 하여 방사선적 골유합 시기와 업무로의 복귀 시기를 확인하였다. 결과: 총 33명의 환자가 본 연구에 참여하였고(남자 9명, 여자 24명), 환자들의 평균 나이는 48.7세(16-80세)였다. 제1 구역이 24명, 제2 구역이 9명이었고 전체 33명의 환자 중 22명에서 2 mm 이상의 골절 전위가 관찰되었고 관절 침범은 9명, 분쇄 골절은 5명에서 관찰되었다. 제1 구역에서 제2 구역에 비하여 통계적 의미 있는 업무로의 복귀를 보였고 최종 추시 시 AOFAS score는 우수한 결과를 보였고 통계적 차이는 없었다. 골절의 전위 정도, 관절 침범 여부, 분쇄 정도를 분류, 비교하였을 때 방사선적 유합 시기, 업무 복귀 시기에 있어 통계적 차이는 없었으며 모든 경우에 있어 최종 추시 시 만족할 만한 결과를 보였다. 결론: 제5 중족골 기저부 골절에서 골절의 위치, 전위, 관절 침범, 분쇄 여부에 관계없이 조기 체중부하를 허용하여도 만족할 만한 임상적 결과를 얻을 수 있다. 제5 중족골 기저부 골절에서 조기 체중부하하 보존적 치료는 우수한 임상 결과를 얻을 수 있는 좋은 치료 방법이라 생각된다.