• 로봇학회논문지
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• 제17권3호
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• pp.322-333
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• 2022

The Avatar robot, which is one of the teleoperation robots, aims to enable users to feel the robot as a part of the body to intuitively and naturally perform various tasks. Considering the purpose of the avatar robot, an end-effector identical to a human hand is advantageous, but a robotic hand with human hand level performance has not yet been developed. In this paper we propose a new 3-finger robotic hand with human-avatar hand posture mapping algorithm which were integrated with TOCABI-AVATAR, one of the teleoperation system. Due to the flexible rolling contact joints and tendon driven mechanism applied to the finger, the finger could implement adaptive grasping and absorb the impact force caused by unexpected contacts. In addition, human-avatar hand mapping algorithm using five calibration hand postures propose to compensate physical differences between operators. Using the TOCABI-AVATAR system with the robotic hands and mapping algorithm, the operator can perform 13 out of 16 hand postures of grasping taxonomy and 4 gestures. In addition, using the system, we participated in the ANA AVATAR XPRIZE Semi-final and successfully performed three scenarios which including various social interactions as well as object manipulation.

• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2005년도 제22회 학술대회 발표 논문집
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• pp.207-212
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• 2005

• 한국재료학회지
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• 제15권10호
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• pp.644-651
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• 2005

The thermal analysis of $Al(OH)_3-SiO_2-AIF_3$ system was done. The thermal behaviors of components and the effect of moisture on the formation of mullite were investigated via TG-DTA and XRD analysis. The mixture of $Al(OH)_3,\;SiO_2,\;AIF_3$showed two endothermic peaks with drastic weight loss and one exothermic peak. Fluorotopaz was formed at $800^{\circ}C$ and turned into mullite completely at $1100^{\circ}C$. But the mixture $Al_2O_3$ of or dehydrated $Al(OH)_3$ and $SiO_2$ could not form mullite even at $1200^{\circ}C$ in which the crystalline phases were $\alpha-Al_2O_3$ ana cristobalite. It was found that the synthesized mullite was aciculate shaped single crystalline whisker.

• 한국재료학회지
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• 제15권10호
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• pp.621-625
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• 2005

Effects of rf power, pressure, sputtering gas composition, and substrate temperature on the deposition rate of the $WC_x$ coatings were investigated. The effects of rf power and sputtering gas composition on the hardness and corrosion resistance of the $WC_x$ coatings deposited by reactive sputtering were also investigated. X-ray diffraction (XRD) and Auger electron spectroscopy (AES) analyses were performed to determine the structures and compositions of the films, respectively. The hardnesses of the films were investigated using a nanoindenter, scanning electron microscopy, ana a salt-spray test, respectively. The deposition rate of the films was proportional to rf power and inversely proportional to the $CH_4$ content of $Ar/CH_4$ sputtering gas. The deposition rate linearly increased with increasing chamber pressure. The hardness of the $WC_x$ coatings Increased as rf power increased. The highest hardness was obtained at a $Ar/CH_4$ concentration of $10 vol.\%$ in the sputtering gas. The hardness of the $WC_x$ film deposited under optimal conditions was found to be much higher than that of the electroplated chromium film, although the corrosion resistance of the former was slightly lower than that of the latter.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.172-177
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• 2004

This paper presents the results of the structural analysis and optimal design of frames of the UUV(Unmanned Underwater vehicle) to be operated at 6000m depth in the ocean. The structure of the UUV system can be classified into two structure, Launcher ana ROV. Frame of the launcher will be made by Galvanized Steel which has high strength and corrosion-resistant but this material has high specific gravity for tile object to be weight in the water Similarly, ROV will be made by AI6061-T6, and frame of the ROV will be fix many instruments and syntactic buoyancy materials. Before fabrication of tile frame, we performed sensitivity analysis - change in weight due to $\pm1\%$ change in design variables, for easy choice by change of dimension of the frame.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.117-122
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• 2004

This study investigates the spatial and temporal distribution characteristics and relationships among water quality parameters, which based on 6 years' data(from 1989 to 1994) measured at 16 stations on Jinhae Bay. The results of these analysis, monthly variations range between surface and bottom layer of water quality had a tendency to increase and decrease, and appeared to be at the maximum value in August. The relationships between concentration of COD ana nutrients(DIN and DIP), which obtained by correlation analysis of water quality, were shown $85\%$ and $74\%$, respectively. Using the cluster analysis to develop the division of the sea basin by the dendrogram, before and after dredging of Masan bay and operating a sewage disposal plant, the variation characteristics of water quality of Jinhae Bay were discussed. Through it, we can see the serious pollution of northen sea basin of Jinhae Bay(B2) although dredging Masan bay and operating the sewage disposal plant. As the results, it doesn't appear the improvement effect of water quality in spite of carrying out the effort of water quality improvement.

• Nuclear Engineering and Technology
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• 제44권3호
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• pp.343-354
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• 2012

Primary water stress corrosion cracking (PWSCC) is a major safety concern in the nuclear power industry worldwide. PWSCC is known to initiate only in the condition in which sufficiently high tensile stress is applied to alloy 600 tube material or alloy 82/182 weld material in pressurized water reactor operating environments. However, it is still uncertain how much tensile stress is re-quired to generate PWSCC or what causes such high tensile stress. This study was performed to pre-dict the magnitude of weld residual stress and operating stress and compare it with previous experi-mental results for PWSCC initiation. For the study, a pressurizer safety nozzle was selected because it is reported to be vulnerable to PWSCC in overseas plants. The assessment was conducted by nu-merical analysis. Before performing stress analysis for plant conditions, a preliminary mock-up ana-lysis was done. The result of the preliminary analysis was validated by residual stress measurement in the mock-up. After verification of the analysis methodology, an analysis under plant conditions was conducted. The analysis results show that the stress level is not high enough to initiate PWSCC. If a plant is properly welded and operated, PWSCC is not likely to occur in the pressurizer safety nozzle.

• International Journal of Fluid Machinery and Systems
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• 제2권1호
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• pp.72-79
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• 2009

The effect of symmetric and asymmetric micro regenerative pump impellers on their pressure performance was studied. The shut off head of the pump with the symmetric impeller was about 2.5 times as that with the asymmetric impeller. The computation of the internal flow was performed to clarify the cause of the increase of the head. It was found that the contribution of the angular momentum supply was larger than that of shear stress for the head development in both cases. The larger head and momentum supply in the case of the symmetric impeller were caused by larger recirculated flow rate and larger angular momentum difference between the inlet and outlet to the impeller. The larger recirculated flow rate was caused by smaller pressure gradient in the direction of recirculated flow. The decrease of the circumferential velocity in the casing was attributed to the smaller local flow rate in the casing.

• Environmental Analysis Health and Toxicology
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• 제17권4호
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• pp.299-305
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• 2002

심폐 지구력은 유전인자에 의해 부분적으로 결정되며, 현재까지 이루어진 연구 결과에 의하면 안지오텐신 전환효소 유전자에 존재하는 다형성과 이 형질 사이에 유의한 관련성이 보고되고 있다. 그러나, 이러한 연구는 주로 서양인을 대상으로 수행되었기 때문에 유전적 배경이 다른 아시아 집단에 대해서는 아직까지 이렇다 할 연구 성과가 없는 실정이다. 이에, 본 연구에서는 아시아 집단중에서도 민족적으로 순수한 한국인 집단을 대상으로 안지오텐신 전환효소 유전자에 존재하는 다향성이 한국인 집단에서도 심폐 지구력과 유의한 관련성이 있는 지를 조사하였다. 그러나, 한국인 운동선수군을 대상으로 한 연구에서는 안지오텐신 전환효소 유전자의 다향성이 심폐 지구력을 비롯한 신체 계측치 및 생화학적인 측정치 들과 어떠한 관련성도 나타내지 않았다(P＜0.05). 그러나, 본 연구 대상으로 다양한 종목에서 선발된 운동선수들을 표본으로 하였기 때문에, 단일 종목의 운동 선수군을 대상으로 한 추시가 요구된다.

• 동의신경정신과학회지
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• 제20권3호
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• pp.121-132
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• 2009

Objectives : This study was done to investigate the relativity of thermography to HRV(heart rate variability) in Sasang constitutional groups. Methods : We investigated 87 healthy workers consisted of 10 Taeumin, 47 Soeumin, 30 Soyangin. After diagnosing the Sasang constitution by QSCCII(Questionnaire for the Sasang Constitutional Classification), we ana lysed their HRV -time domain and frequency domain and also checked their thermography in April 2009. Results & Conclusions : Analysing the thermography, The whole skin temperature was showed equaly in many Taeumin, the face, Upper burner skin temperature was showed high in many Soeumin, and the abdomen skin temperature was showed low in many Soyangin. The relativity of the sympathetic index to skin temperature was high in Taeumin. The higher sympathetic index, the higher Upper burner skin temperature in Taeumin, the higer most of the skin temperature in Soyangin, lower the whole skin temperature in Soeumin.