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매니폴드 노즐 형상변화가 웨이퍼 캐리어 내부 유동특성에 미치는 영향
정문기(M.K. Jung),강병화(B.H. Kang),강현영(H.Y. Kang),양연희(Y.H. Yang),김요환(Y.H. Kim),김윤제(Y.J. Kim) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12
Wafer carrier is important equipment in semiconductor manufacturing processes which is used to remove contaminants from wafers by purging gas. However, having a uniform purging gas is difficult because the purging gas inlet in the wafer carrier is located at the lower left of the carrier. As a result, uneven flow patterns are formed inside the carrier, so that contamination of the wafer can not be smoothly removed. The numerical analysis was conducted to investigate the effect of manifold nozzle shape change on the flow characteristics of a wafer carrier using ANSYS Fluent 18.1. The turbulence kinetic energy and velocity distributions are investigated to obtain the most efficient aspect ratio of the nozzle(η).
근골격 시뮬레이션을 이용한 보행 중 지면반력 중심위치 추정방법
정이환(Yihwan Jung),정문기(Moonki Jung),이건우(Kunwoo Lee),구승범(Seungbum Koo) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10
Musculoskeletal kinematics analysis is possible when all external force information including ground reaction force(GRF) are provided. However using force plate has limitation in installation depending on environments. In this study, we developed a simulation method that can predict the center of pressure on the foot from kinematics data utilizing artificial muscles between the foot and ground, which are conditionally activated during musculoskeletal simulation. The artificial muscles on the foot were activated when the distance of foot node and ground node is smaller than the pre-definded value. In this study we demonstrated the predictions of ground reaction force and center of pressure on the foot using inverse dynamics simulation with conditionally activated artificial muscles. The results were validated against the measured values from a force plate.
정이환(Yihwan Jung),정문기(Moonki Jung),이건우(Kunwoo Lee),구승범(Seungbum Koo) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11
Human dynamics simulation requires external forces and moment. During gait analysis the full ground reaction forces and moments can be obtained using force plates. In some testing situations such as slope ascending/descending and stair walking full external ground reactions cannot be easily obtained while the joint kinematics can be obtained using camera systems. Recently mobile insole type pressure mat systems have been developed. The mobile pressure mat provides the pressure distribution and the center of pressure on the foot during walking though the shear forces (FX and FY) and the free moment along the vertical direction to ground (MZ) cannot be provided. The purpose of our study was to create a human musculoskeletal model and simulation to predict the shear forces and free moment from joint kinematics and pressure mat data. The predicted values were validated against the true values obtained from force plates.
제품과 인체의 통합 모델을 바탕으로 한 스미스 스쿼트 운동의 가상 시험 프레임워크
이해린,정문기,이상헌,Lee, Haerin,Jung, Moonki,Lee, Sang Hun 대한기계학회 2017 大韓機械學會論文集A Vol.24 No.2
The barbell squat is a fundamental physical exercise for strengthening the lower body and core muscles. It is an integral part of training and conditioning programs in sports, rehabilitation, and fitness. In this paper, we proposed a virtual test framework for squat exercises using a Smith machine to simulate joint torques and muscle forces, based on an integrated product-human model and motion synthesis algorithms. We built a muscular skeletal human model with boundary conditions modeling the interactions between the human body and a machine or the ground. To validate the model, EMG, external forces, and squat motions were captured through physical experiments by varying the foot position. A regression-based motion synthesis algorithm was developed based on the captured squat motions to generate a new motion for a given foot position. The proposed approach is expected to reduce the need for physical experiments in the development of training programs. 본 연구에서는 스미스 머신을 이용한 스쿼트 운동에 대한 가상 테스트 프레임웍을 제안하고 구현하였다. 이를 위하여 인체 및 제품의 통합 모델을 개발하고, 실험 데이터를 바탕으로 자세의 변화에 따른 새로운 동작을 생성하는 알고리즘을 개발한 후, 가상의 조건에서 동작을 생성하여 인체의 관절에 걸리는 토크와 근육에 걸리는 힘을 시뮬레이션 하는 전체 시스템을 개발하였다. 이 시스템을 검증하기 위하여 동작 수집과 더불어 EMG와 지면반력에 대한 데이터를 수집하여 시뮬레이션 결과가 실제와 잘 맞는지 확인하였다. 이 시스템을 확장시켜 사용한다면 다양한 조건에서 운동하였을 때 신체 근육과 관절에 어떤 영향을 끼치는 지 시뮬레이션 해봄으로써 적절한 운동 프로그램을 효과적으로 개발할 수 있을 것으로 기대된다.