충적대수층 조사를 위한 모래와 점토의 유도분극 특성 고찰

최상혁 ( Sang Hyuk Choi ),김형수 ( Hyoung Soo Kim ),김지수 ( Ji Soo Kim ) 대한지질공학회 2008 지질공학 Vol.18 No.4

충적층의 구성물질 중에서 포화된 실트 또는 점토층은 다른 층들에 비해 상대적으로 낮은 전기비저항 값을 나타낸다. 따라서 자료해석에 있어서 실트 및 점토층이 전기비저항이 작고 투수성이 높은 대수층으로 오인될 수 있다. 본 연구에서는 이러한 문제를 극복하고 충적층 내 포화된 실트 또는 점토층과 모래 또는 자갈 대수층을 구분하기 위해 충적층을 구성하고 있는 물질의 전기비저항 및 유도분극 값을 함께 측정하는 실내실험을 실시하였다. 실험결과 실트 또는 점토시료가 모래시료보다 충전성이 높게 나타났으며, 또한 모래와 점토 혼합시료에서 점토함량이 증가함에 따라 전기비저항은 감소하고 충전성은 증가하다가 다시 감소하는 경향을 보였다. In general, water-saturated silt or clay alluvium is characterized with relatively low-resistivity. Thus we often encountered the problem that such a low-resistivity layer is misguided to be good aquifer of high-permeability and low-resistivity in the development of groundwater. This research was conducted with an emphasis on the identification of saturated silt or clay layer from the aquifer by performing the laboratory experiment of IP and resistivity methods on the various materials consisting of alluvium aquifer. Silt or clay layer is found to be characterized with the higher chargeability zone, compared to the sand layer. Regarding the mixture of sand and clay, the higher clay volume, the lower resistivity and the higher chargeability. Subsequently chargeability decreases.

자동차 후드의 정강성을 고려한 위상 최적화

최상혁(Sang Hyuk Choi),박재용(Jae Yang Park),황준성(Joon Sung Hwang),김민수(Min Sue Kim),한석영(Seog Young Han) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

Topology optimization of the inner reinforcement for a vehicle’s hood has been performed by evolutionary structural optimization (ESO) using a smoothing scheme. The purpose of this study is to obtain optimal topology of the inner reinforcement for a vehicle's hood considering the static stiffness of bending and torsion simultaneously. To do this, the multiobjective optimization technique was implemented. Optimal topologies were obtained by the ESO method. From several combinations of weighting factors, a Pareto-optimal solution was obtained. Also, a smoothing scheme was implemented to suppress the checkerboard pattern in the procedure of topology optimization. It is concluded that ESO method with a smoothing scheme is effectively applied to topology optimization of the inner reinforcement of a vehicle’s hood considering the static stiffness of bending and torsion.

초음파 재활치료 시 PTT와 생리변수의 상관관계 분석

金性民(Sung-Min Kim),崔相赫(Sang-Hyuk Choi),李萬杓(Man-Pyo Lee),崔炳哲(Byeong-Cheol Choi),鄭會昇(Whoi-Seong Jung),朴聖允(Sung-Yoon Park) 대한전기학회 2007 전기학회논문지 Vol.56 No.8

Currently, the signal of the human body is measured with various methods, and a noninvasive investigation of various methods is useful diagnosis method. PTT(Pulse Transit Time) which is noninvasive investigation make use of to estimate the physiological phenomena. PTT has a latent information of cardiovascular system. So we have the experiments for analysis of the relations between PTT and physiological parameters. We examine to correlate to the physiological parameters, an age and degree of paralysis on the ultrasound therapy. The 40 patients who has a such paralysis join our experiment, and we obtain the PTT data that normal condition and states after ultrasound therapy. We study that PTT after the ultrasound therapy for patients who have a paralysis was related to an age and degree of paralysis.

아파트 주거속성이 거주자의 지각된 가치와 건설사 신뢰 및 거주의도에 미치는 영향

손정영(Jung-Young Son),최상혁(Sang-Hyuk Choi) 한국상품학회 2022 商品學硏究 Vol.40 No.5

최근 전 세계적으로 ESG 경영이 주목받고 있어 ESG 가치 실현을 위해 정부와 기업 차원에서 적극적 움직임을 보이고 있으며 국민적 관심도 증가하고 있는 추세이다. 건설업계에서도 소비자들에게 환경친화적 주거공간을 제공하는 등의 노력을 통해 ESG 경영을 실천하고 있다. 본 연구는 아파트 거주자를 대상으로 아파트 주거속성의 6개 차원(자재 친환경성, 관리사무소 서비스, 주거단위 특징, 공공시설, 사회환경, 그린 품질)이 거주자가 지각한 가치(쾌락적, 실용적)에 미치는 영향을 알아보고, 지각된 가치는 건설사에 대한 신뢰와 아파트 거주의도에 어떠한 영향을 미치는가를 파악하고자 한다. 온라인 서베이 회사의 패널들을 대상으로 1개월에 걸쳐 설문조사가 실시되었다. 3,457명의 패널들에게 설문조사 내용이 발송되어 618명이 설문에 응답하였으나, 불성실한 응답과 무응답으로 인해 연구에 부적합한 15부를 제외하고 603명의 응답이 분석에 이용되었다. 연구 결과, 주거속성 중 관리사무소 서비스가 실용적 가치에 미치는 영향을 제외하고 모든 관계가 유의한 영향이 있는 것으로 나타났다. 본 연구를 통해 얻은 결과는 건설사와 건설 관련 정책 담당 실무자들이 아파트 분양시장에 대한 전략과 계획 수립 및 실천에 유용한 자료로 쓰일 수 있을 것이다. The government, companies, and the general public are all actively taking action to realize the advantages of ESG management, which has recently gained attention on a global scale. The construction industry is also practicing ESG management through efforts such as providing eco-friendly residential spaces to consumers. This study examined the effects of 6 dimensions of apartment attributes (material eco-friendliness, management office services, dwelling unit features, public facilities, social environment, quality of green space) on the perceived values (hedonic and utilitarian) of apartment occupants. This study also aims to investigate the effect of perceived value on the trust in the construction company and the intention to live in an apartment. The findings show that 5 sub-dimensions except for management office services had significant positive effects on utilitarian value. And, 6 sub-dimensions of apartment attributions had significant positive effects on hedonic value. The findings of this study can be used as useful data for construction companies and construction-related policy practitioners to establish and implement strategies and plans for the apartment sale market.

안드로이드 기반 영숙어 학습 애플리케이션 개발

현영민 ( Yeong-min Hyeon ),최상혁 ( Sang-hyuk Choi ),최현민 ( Hyun-min Choi ),최진구 ( Jin-gu Choi ),서대영 ( Dae-yung Seo ) 한국정보처리학회 2011 한국정보처리학회 학술대회논문집 Vol.18 No.2

최근 스마트 디바이스의 발전이 급격하게 이루어지면서 관련 애플리케이션 연구와 개발도 활발하게 진행되고 있으며, 거의 모든 시간을 휴대하는 기기로 자리 잡게 되었다. 본 논문은 안드로이드를 기반으로 한 애플리케이션으로 사람의 망각주기인 1일,7일,30일마다 반복학습을 통해 가장 많이 사용하는 동사에서 파생되는 숙어들을 빠르고 효율적으로 학습하는 프로그램을 구현하였다.

자동차 후드의 정강성을 고려한 위상 최적화

한석영(Seog Young Han),최상혁(Sang Hyuk Choi),박재용(Jae Yong Park),황준성(Joon Seong Hwang),김민수(Min Sue Kim) 한국생산제조학회 2007 한국생산제조학회지 Vol.16 No.1

Topology optimization of the inner reinforcement for a vehicle’s hood has been performed by evolutionary structural optimization(ESO) using a smoothing scheme. The purpose of this study is to obtain optimal topology of the inner reinforcement for a vehicle’s hood considering the static stiffness of bending and torsion simultaneously. To do this, the multiobjective optimization technique was implemented. Optimal topologies were obtained by the ESO method. From several combinations of weighting factors, a Pareto-optimal solution was obtained. Also, a smoothing scheme was implemented to suppress the checkerboard pattern in the procedure of topology optimization. It is concluded that ESO method with a smoothing scheme is effectively applied to topology optimization of the inner reinforcement of a vehicle’s hood considering the static stiffness of bending and torsion.

5-Bar 스피링을 이용한 마이크로매스퓰레이터의 변위증폭

한석영(Seog Young Han),윤상준(Sang Jun Yoon),박재용(Jae Yong Park),황준성(Jun Seong Hwang),최상혁(Sang Hyuk Choi),김민수(Min Sue Kim) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

A micromanipulator means the device that can manipulate the object with high precision. It is required high natural frequency and sufficient workspace. To cope with this requirement, flexure hinge mechanisms have been proposed. However, previous designs are hard to satisfy the functional requirements of the system due to difficulty in modeling and optimization process applying the independent axiomatic design. Therefore, this paper suggests a new design based on semi-coupled, axiomatic design. A planar 3 DOF parallel type micromanipulator is chosen as an exemplary device. To check the effectiveness of the 5-bar spring, simulation is performed by FEM. The simulation result satisfy natural frequency and a workspace, simultaneously, which is in very close agreement with the specified goal of design.

PCB판의 위상 최적화를 위한 재료혼합법의 개발

한석영(Seog Young Han),김민수(Min Sue Kim),황준성(Joon Sung Hwang),최상혁(Sang Hyuk Choi),박재용(Jae Yong Park),이병주(Byung Ju Lee) 한국생산제조학회 2007 한국생산제조학회지 Vol.16 No.1

A material mixing method to obtain an optimal topology for a structure in a thermal environment was suggested. This method is based on Evolutionary Structural Optimization(ESO). The proposed material mixing method extends the ESO method to a mixing several materials for a structure in the multicriteria optimization of thermal flux and thermal stress. To do this, the multiobjective optimization technique was implemented. The overall efficiency of material usage was measured in terms of the combination of thermal stress levels and heat flux densities by using a combination strategy with weighting factors. Also, a smoothing scheme was implemented to suppress the checkerboard pattern in the procedure of topology optimization. It is concluded that ESO method with a smoothing scheme is effectively applied to topology optimization. Optimal topologies having multiple thermal criteria for a printed circuit board(PCB) substrate were presented to illustrate validity of the suggested material mixing method. It was found that the suggested method works very well for the multicriteria topology optimization.

PCB판의 위상 최적화를 위한 재료혼합법의 개발

한석영(Seog Young Han),김민수(Min Sue Kim),박재용(Jae Yong Park),황준성(Joon Sung Hwang),최상혁(Sang Hyuk Choi),이병주(Byung Ju Lee),김선정(Seon Jeong Kim) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

A material mixing method to obtain an optimal topology for a structure in a thermal environment was suggested. This method is based on Evolutionary Structural Optimization (ESO). The proposed material mixing method extends the ESO method to a mixing several materials for a structure in the multicriteria optimization of thermal flux and thermal stress. To do this, the multiobjective optimization technique was implemented. The overall efficiency of material usage was measured in terms of the combination of thermal stress levels and heat flux densities by using a combination strategy with weighting factors. Optimal topologies having multiple thermal criteria for a printed circuit board (PCB) substrate were presented to illustrate validity of the suggested material mixing method. It was found that the suggested method works very well for the multicriteria topology optimization.