• Transactions on Control, Automation and Systems Engineering
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• 제4권1호
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• pp.9-16
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• 2002

In this paper, we intend to demonstrate a new intuitive force-feedback device for advanced VR applications. Force feed-back for the device is tension based and is characterized by 7 degrees of freedom (DOF); 3 DOF for translation, 3 DOF for rotation, and 1 DOF for grasp). The SPIDAR-G (Space Interface Device for Artificial Reality with Grip) will allow users to interact with virtual objects naturally by manipulating two hemispherical grips located in the center of the device frame. We will show how to connect the strings between each vertex of grip and each extremity of the frame in order to achieve force feedback. In addition, methodologies will be discussed for calculating translation, orientation and grasp using the length of 8 strings connected to the motors and encoders on the frame. The SPIDAR-G exhibits smooth force feedback, minimized inertia, no backlash, scalability and safety. Such features are attributed to strategic string arrangement and control that results in stable haptic rendering. The design and control of the SPIDAR-G will be described in detail and the Space Graphic User Interface system based on the proposed SPIDAR-G system will be demonstrated. Experimental results validate the feasibility of the proposed device and reveal its application to virtual reality.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.211-212
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• 2012

• 대한치과교정학회지
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• 제29권5호
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• pp.551-562
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• 1999

본 연구는 치아를 실험적으로 이동시킬 때, 교정력의 크기와 적용방법에 따른 치아이동 양상의 차이가 존재하는 지의 여부와 치근흡수와의 관련 여부에 대하여 평가하고자 하였다. 300g전후의 건강한 수컷 흰쥐 24마리를 세 군으로 나누고 상악 제 1대구치와 상악중절치 사이에 NiTi closed coil spring을 장착하여, 각 군당 50g(A군), 100g(B군), 25g(C군)을 적용하였고 C군의 경우에는 교정력을 적용한지 4일째 50g으로 힘을 증가하였다. 15일간 교정력을 적용하는 동안 매일 ehter로 흡입 마취를 시행하고 치아이동거리를 digital caliper로 측정하고 15일간의 실험기간 종료 후 상악 제1대구치 치근부의 조직표본을 제작하여 광학 현미경으로 관찰한 바 다음과 같은 결과를 얻었다. 1. 각 군별 15일간 총 치아이동거리는 B군에서 가장 컸고, 그 다음 C군, A군의 순이었으나 통계학적으로 유의성있는 차이는 없었다. 2. A, B, C군 모두 전형적인 치아의 이동양상을 보여주었으며 치아이동 지체기가 끝난 날은 C, B, A군의 순서로 각각 7, 8, 9일째 끝났으나 통계학적으로 유의성있는 차이는 없었다. 3. A, B, C군 모두에서 치근의 흡수양상을 관찰할 수 있었고, 특히 B군에서 가장 심한 치근흡수양상을 보여주었고, C군에서 치근흡수의 양상이 가장 적었다. 이상을 종합해볼 때, 교정력이 크다고 하여 더 빠른 치아이동이 일어난다고 볼 수 없으며 교정력이 클수록 초자양변성대가 광범위하게 형성되어 오히려 치근의 흡수도 증가하므로 교정력을 적용할 때 초기 교정력을 보다 적게 적용하여 초자양변성대 형성범위를 줄인 뒤 교정력을 증가시키는 방법이 치근흡수를 최소화하면서 효과적인 치아이동을 얻을 수 있을 것으로 생각된다.

• Applied Biological Chemistry
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• 제32권3호
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• pp.216-221
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• 1989

조리조건이 익혀진 콩의 품질에 미치는 영향을 알아보고저 인스트론을 사용하여 텍스쳐의 변화를 측정하였고 puncture force와 shear force의 측정결과를 사용하여 조리온도를 달리하였을 때의 cooking kinetics를 검토하였다. 관능검사에 의해 알맞게 익혀졌을 때 황색콩의 puncture force는 0.15kg, shear force는 1.2kg/g-soybean으로 나타났으며 활성화에너지 값은 각각 14,540, 21,374 cal/g-mole이었고 z값은 $42.1,\;37.4^{\circ}C$이었다. 이러한 결과로 조리된 콩의 텍스쳐는 침지와 조리 조건에 따라 크게 영향받음을 알 수 있었다.

• 한국식품저장유통학회지
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• 제7권1호
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• pp.38-43
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• 2000

Changes in firmness and pectin contents during maturation and sotrage of Stsuma mandarin (Citrus Unshiu Marc. var. miyagawa) were investigated. Firmness of fruits was decreased quickly from 1,176.8g-force to 503.6g-dorce. Satsuma mandarin was stored at 3$^{\circ}C$ and 85%${\pm}$5% relative humidity. Firmness were decreased from 538.9g-force to 336.9g-force during storage. Alcohol-insoluble solid(AIS) of peel and flesh were decreased quickly from 27.04g/100g to 12.30g/100g, and from 2.67g/100g to 1.91g/100g during maturation of fruits. During storage of fruits, AIS of peel was decreased from 14.32g/100g to 12.06g/100g . During maturation of fruits, water soluble pectin (WSP) of peel were increased from 420.82mg/100g to 601.62mg/100g as wet basis. Hexametaphosphate soluble pectin (HMP) was also increased from 450.17mg/100g to 577/53mg/100g. hydrochloricacid soluble pectin (HSP) was decreased from 1938.30 mg/100g to 695.14mg/100g. During storage of fruits, HMP and HSP of peel was decreased from 507.82mg/100g to 695.14mg/100g. During storage of fruits, HMP and HSP of peel was decreased from 527.82mg/100g to 275.47mg/100g , and from 672.28mg/100g to 351.36mg/100g, respectively. WSP of peel was increased from 543.70mg/100g to 584.31mg/100g. Total pectin substance (TPS) of peel was decreased from 2809.79 mg/100g to 1874.29mg/100g during maturation, and from 1723.80mg/100g to 1211.14mg/100g during storage, respectively. Composition ratio of pectin was in order of WSP>HSP>HMP.

• 산업경영시스템학회지
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• 제37권4호
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• pp.212-217
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• 2014

Recently, Korea Air Force has been facing a lot of problems in its pilot training system such as training time shortage due to the expensive gas price, noise pollution and difficulties in finding airspace for training. To tackle these problems, a new training system (called L-V training system) using both aircraft and its simulator has been suggested. In the system, a data link is established between aircraft and simulator to exchange their flight information. Using the flight information of simulator, aircraft can perform various air missions with or against imaginary aircraft (i.e., simulator). For this system, it is crucially important that fair fighting condition has to be guaranteed between aircraft and simulator. In this paper, we suggested an approach to impose a maneuvering restriction to simulator in order to provide fair fighting condition between aircraft and simulator.

• PNF and Movement
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• 제9권1호
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• pp.31-38
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• 2011

Purpose : Sit-to-stand (STS) is one of the important activities of daily living (ADL) and each of its parameters is used frequently. This study aimed to examine the influence of different seat height on performance time and floor reaction force strength during an STS movement. Methods : Fifteen young-adult male subjects participated in this study. The subjects were divided into three groups based on lower leg length. Subjects performed an STS movement twice from chairs at height adjusted by the lower leg length of each subject. To examine the influence of the chair seat height, ground reaction forces during a STS performed with 3 chair heights adjusted to each subjects lower leg length were compared. Results : Vertical ground reaction force and time during an STS movement were measured to evaluate. Parameters regarding ground reaction force were selected for analyses. Significant differences were found in ground reaction force at G1 was greater than G2 and G3. Conclusion : The STS movement achievement strategy differed since chair seat height changes relatively by the difference in lower leg length. When conducting the ability to achieve STS movement rating test, chair seat height considering each subject's lower leg length may be needed.

• 한국육종학회지
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• 제43권4호
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• pp.311-317
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• 2011

이 실험은 다양한 크기의 종자로부터 콩나물을 키우고 콩나물의 생장 및 물리적 특성으로 조사함으로써 나물콩 품종육성과 나물콩 품질평가를 위한 기초자료를 얻고자 수행되었다. 대립 및 중소립 재배종 각각 3품종, 야생종과 재배종 교잡종 소립 3품종, 극소립 야생콩 3계통을 공시하여 4일간 콩나물을 키운 뒤 생육특성과 콩나물의 물성을 조사하였다. 콩나물 재배 96시간 후 배축 길이는 품종간 차이가 컸는데 황금콩, 풍산나물콩 및 소영이 가장 길었으며 극소립인 야생콩 계통들이 짧았다. 특히 대립종인 황금콩은 72시간까지 소립 나물콩 품종들과 비슷하게 생장하였으며 96시간 후에는 15.9 cm로 가장 길었다. 극소립 야생종계통은 재배 48시간 후부터 72시간 사이에 급격하게 증가하였으며 원료콩 1 g당 생장량도 월등히 많았으나 다른 품종들은 비슷한 증가양상을 보였다. 재배 96시간 후 단위 종자당 콩나물 생체중 증가비율은 소립일수록 컸으며 콩나물 수율도 소립종일수록 높은 경향을 보였다. 생체 배축의 hardness는 장엽콩이 3,505 g으로 가장 컸고 야생종 YWS516이 1,750 g으로 가장 낮았다. Mastication는 태광콩이 1,650 g으로 가장 높았으며 YWS516이 1,079g으로 가장 낮았으며 배축의 cutting force는 은하콩이 133 g으로 가장 크고 YWS516이 51 g으로 가장 낮았다. 익힌 후의 cutting force는 모든 품종에서 증가하였는데 전체적으로 종자크기가 클수록 물성특성이 증가하는 것으로 나타났다. 배축의 breaking force는 장엽콩이 83.5 g로 가장 컸고 야생콩이 가장 낮아 종자크기가 클 수록 증가하였다.

• 한국자동차공학회논문집
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• 제18권3호
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• pp.116-126
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• 2010

The Korean rolling stock safety regulation stipulates that the collision deceleration of a car body should be maintained under average 5g and maximum 7.5g during train collisions. One-dimensional dynamic model of a full rake train, which is made up of nonlinear springs/bars-dampers-masses, is often used to estimate the collision decelerations of car bodies in a basic design stage. By the way, the previous studies have often used some average force-deformation curve for energy absorbing structures in rolling stock. Through this study, we intended to analyse how much the collision deceleration levels are influenced by the initial peak force modeling in the one-dimensional force-deformation curve. The numerical results of the one-dimensional dynamic model for the Korean High-Speed Train show that the initial peak force modeling gives significant effect on the collision deceleration levels. Therefore the peak force modeling of the force-deformation curve should be considered in one-dimensional dynamic model of a full rake train to evaluate the article 16 of the domestic rolling stock safety regulations.

• 소성∙가공
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• 제15권1호
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• pp.82-88
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• 2006

In this paper, the web-based monitoring system is developed for the effective process monitoring of mold manufacturing using web. In developed system, the cutting force for monitoring the manufacturing condition is measured using hall-sensor that is low cost and useful to be installed in a machine tool indirectly. Specially, the current of main spindle in a machine tool is converted into cutting force by various experiments. For effective web-based monitoring, the program which runs in the local computer of client is made to exchange message between a server and a client by making of ActiveX control and the result of manufacturing is shown on web-browser by Ch language. The developed system in this study is the foundation of establishing E-manufacturing in mold factory.