• 재활복지공학회논문지
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• 제8권4호
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• pp.283-289
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• 2014

본 논문에서는 능동형 대퇴의지 시스템의 설계 및 최적화에 대한 연구를 진행하였다. 본 연구의 능동형 대퇴의지 시스템은 무릎부의 1 자유도를 통해 슬관절의 움직임을 모사하는데, 실제 다리의 기능을 대체하는 것이므로 사람의 다리 무게와 최대한 유사해야 하며, 경량화가 중요한 요소라고 할 수 있다. 본 연구에서는 기존에 개발된 3-링크 구조의 능동형 의지 시스템의 문제점을 보완하기 위해 기어 구동 방식의 능동형 대퇴의지 시스템을 설계 및 제작하였고, 사용자의 만족감 향상 및 피로도 저감을 위해 최적화를 통한 경량화를 진행하고 유한요소해석을 통해 응력 및 변위 특성을 분석하고 안정성을 검증하였다. 또한 능동형 의지 시스템이 사용자의 보행 의도에 맞추어 작동하기 위해 의지의 인공 발에 스트레인 게이지를 부착하여 보행시 발의 앞, 뒷부분에 각기 다르게 가해지는 하중을 측정, 보행 주기를 판단할 수 있도록 한다. 이 때 스트레인 게이지는 미세한 변형에도 민감하게 반응하므로 유한요소해석을 통해 적절한 부착위치를 결정하고, 실제 제작 및 실험을 통해 안정성 및 보행주기 판단 여부를 검증한다.

• 한국지역사회생활과학회지
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• 제15권3호
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• pp.45-56
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• 2004

The purpose of this paper is to review research evolution and achievements, major activities, research manpower, and difficulties for social scientists, using IRRI's internal web site and Social Sciences Division's research literatures. The major findings are as follows: 1) Social research started with the establishment of Agricultural Economics Division (AED) in 1966, and it was developed into the Social Sciences Division (SSD) in 1990; 2) Their research has been geared towards developing technological and policy interventions that improve food security and raise the well-being of rice farmers through sustainable increase in the productivity of a rice-based production system; 3) Major activities of social sciences research for about four decades can be classified into the identification of technology needs, technology impact assessment, policy analysis, research prioritization, and capacity building for social science research in NARS (National Agricultural Research Systems). They have become increasingly important in alleviating the poverty of the rice growing and consuming population; 4) Social researchers at IRRI include economists, anthropologists, gender specialists, geographic information specialists, and rural sociologists; 5) Finally, this paper discusses the difficulties faced by social researchers.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.512-518
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• 2011

우리나라는 1980년대 초반부터 조선산업과 더불어 조선기자재업체의 동반 성장을 추구해왔다. 그러나 조선산업발전 추이를 보면 중국이나 동남아시아로 시장이 옮겨갈 것이라는 전망이 나오고 있고, 국제해사기구(IMO)에서는 e-navigation 실현을 예고하는 등 국내외적 여건에 따른 산업계의 신속한 변화뿐만 아니라 국가적 대책과 학계의 연구개발 노력이 절실하다. 본 논문에서는 항해통신장비산업의 특징과 국내외동향, 그리고 연구개발분야를 서술하고, 대표적인 연구개발현황을 소개한다.

• 한국축산시설환경학회지
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• 제13권1호
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• pp.29-34
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• 2007

This study was conducted to develop a reclaimer of the vehicle disinfector to be used at livestock fm. The reclaimer was mainly consisted of ball-valves, geared motors and one-chip processor, and the purpose of the system was to prevent liquid freezing as well as decrease environmental pollution of antiseptic solution. The properly spraying pressure of the vehicle disinfector was found over 1.96 MPa at 1m of the spraying range. While certain amount of the antiseptic solution remained in the injection-pipes, the spray starting time was found not making any significant effect on the remained amount of the antiseptic solution. The amounts of the antiseptic solution remained in the injection-pipes were 50 ml and 270 ml in average, respectively with and without the use of the reclaimer. The reclaimer was the most effective when the connection of the injection-pipe and sprayer line was located below the side-injection-pipe and then connected to the injection-pipe located at the bottom of vehicles.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.647-652
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• 2011

Developments in the teaching of the National Diploma in Building students should be geared towards meeting the needs of the construction industry in South Africa. These needs are usually in the form of skills and knowledge required to resolve thorny issues encountered in practice. The lack of capacity in the construction industry needs to be addressed from the basis of ensuring that the education system caters for both mature entry and matriculation entry students. The paper looks at a comparison in performance between mature entry and matriculation (just finish High School) entry students focusing on the National Diploma in Building students at the University of Johannesburg. The paper will make a comparison between those students who work first before enrolling for their first year National Diploma in Building and those who are directly from high school. Cooperative education involves training and systematically developing students through the acquisition of the requisite skills, attitudes, values and knowledge required to adequately perform in their chosen careers. The paper describes the problems and experiences that have been encountered by both mature and matriculation entry students in their three years of study which affects their performance. The paper will then look at the value of prior experience in enabling students to finish their National Diploma in Building within a three year period. The paper closes with some recommendations for the future.

• Tribology and Lubricants
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• 제34권5호
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• pp.169-174
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• 2018

A multi-stage compressor (MSC) is comprised of several impellers installed in the pinion gear shaft driven by a main bull gear. In the pinion shaft, a thrust collar (TC) is installed to support the thrust load. The TC makes the lubrication system simpler in the MSC; therefore, it is widely used in similar kinds of machinery. Typically, TCs are installed on both sides of the bull gear and pressure is developed in the lubricated area by creating a taper angle on the TC and bull gear surface. In the current study, we developed a numerical analysis model to evaluate the performance of the TC considering its design parameters. We sloved the Reynolds equation using the finite element method and applied the half Sommerfeld condition to consider cavitation. Based on the pressure calculated in the lubricated area, we calculated the power loss and minimum film thickness. In addition, we calculated stiffness and damping using perturbation method. We performed parametric studies using the developed model. The results of the analysis show that the maximum pressure presents in the center area of the TC and it increases with the taper angle. The area over which pressure is developed decreases with the taper angle. The results also show that there is an optimum taper angle providing minimum power loss and maximum film thickness. Additionally, the stiffness and damping decrease with the taper angle. As the applied load increases, the power loss increases and the minimum film thickness decreases. However, the stiffness and damping increase with the applied load.

• 한국콘텐츠학회논문지
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• 제8권8호
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• pp.235-243
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• 2008

본 연구에서는 신한승이 택견을 국가 무형문화재로 지정하기 위하여 어떻게 체계화하고 구성하였는지를 살펴보는데 초점을 맞추었고, 다음과 같은 결론과 의의를 찾을 수 있었다. 첫째, 근대 택견의 전수자로 유일한 송덕기 택견의 기술 구성은 일정한 체계가 없는 낱기술 중심의 놀이 형태로 전래 되었으나, 신한승에 의하여 체계적인 구성을 가진 무예로 발전하게 되고, 급기야 무형문화재로 인정받게 되는 쾌거를 이루었다. 둘째, 신한승은 낱기술로 전래되어 오던 택견을 체계화 하면서 유도, 검도, 합기도, 태권도, 가라테의 수련체계와 기술을 일부 차용하여 근대화 시켰다. 이 과정에서 송덕기 택견이 원형대로 전수되지 않고 변형되었다는 비판이 제기되고 있는 실정이다. 셋째, 신한승은 정통 택견에는 없던 급수 구분제도와 실기심사, 태권도의 품새에 해당하는 본대뵈기 12마당 등을 만들고, 스포츠화를 추구하여 현대적인 학습체계와 대중화에 기여하였다. 본 연구를 통해 택견의 원래 형태와 기술변천 및 구성에 대한 시대적 환경적 윤관을 재조명 할 수 있었으며, 전통화 과정에서 혼재되고 있는 각종 택견 단체들의 논쟁을 이해하는 중요한 참고 자료를 제공할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2290-2295
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• 2005

In this paper, it is developed simulator system of 3 D.O.F parallel robot for educate of expertness. This simulator system is composed of three parts ? 3 D.O.F parallel robot, controller (hardware) and software. First, basic structure of the robot is 3 active rotary actuator that small geared step motor with fixed base. An input-link is connected to this actuator, and this input-link can connect two ball joints. Thus, two couplers can be connected to the input-link as a pair. An end-plate, which is jointed by a ball joint, can be connected to the opposite side of the coupler. A sub-link is produced and installed to the internal spring, and then this sub-link is connected to the upper and bottom side of the coupler in order to prevent a certain bending or deformation of the two couplers. The robot has the maximum diameter of 230 mm, 10 kg of weight (include the table), and maximum height of 300 mm. Hardware for control of the robot is composed of computer, micro controller, pulse generator, and motor driver. The PC used in the controller sends commands to the controller, and transform signals input by the user to the coordinate value of the robot by substituting it into equations of kinematics and inverse kinematics. A controller transfer the coordinate value calculated in the PC to a pulse generator by transforming it into signals. A pulse generator analyzes commands, which include the information received from the micro controller. A motor driver transfer the pulse received from the pulse generator to a step motor, and protects against the over-load of the motor Finally, software is a learning purposed control program, which presents the principle of a robot operation and actual implementation. The benefit of this program is that easy for a novice to use. Developed robot simulator system can be practically applied to understand the principle of parallel mechanism, motors, sensor, and various other parts.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권6호
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• pp.415-424
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• 2004

In this paper, we introduce and investigate a new category of rule-based fuzzy inference system based on Information Granulation(IG). The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of “If..., then...” statements, and exploits the theory of system optimization and fuzzy implication rules. The form of the fuzzy rules comes with three types of fuzzy inferences: a simplified one that involves conclusions that are fixed numeric values, a linear one where the conclusion part is viewed as a linear function of inputs, and a regression polynomial one as the extended type of the linear one. By the nature of the rule-based fuzzy systems, these fuzzy models are geared toward capturing relationships between information granules. The form of the information granules themselves becomes an important design features of the fuzzy model. Information granulation with the aid of HCM(Hard C-Means) clustering algorithm hell)s determine the initial parameters of rule-based fuzzy model such as the initial apexes of the membership functions and the initial values of polynomial function being used in the Premise and consequence Part of the fuzzy rules. And then the initial Parameters are tuned (adjusted) effectively with the aid of the improved complex method(ICM) and the standard least square method(LSM). In the sequel, the ICM and LSM lead to fine-tuning of the parameters of premise membership functions and consequent polynomial functions in the rules of fuzzy model. An aggregate objective function with a weighting factor is proposed in order to achieve a balance between performance of the fuzzy model. Numerical examples are included to evaluate the performance of the proposed model. They are also contrasted with the performance of the fuzzy models existing in the literature.

• 한국교육학연구
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• 제23권1호
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• pp.379-404
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• 2017

본 연구는 대학의 성인전담 단과대학의 운영방안을 구체적이고 실질적인 차원에서 모색하고자 하였다. 이를 위해 성인학습자를 위한 단과대학 추진 배경으로 성인학습자의 능력개발 요구에 대한 기회 확대, 고등평생교육제도 실행에서의 문제, 현행 평생 학습중심대학 사업의 한계 등을 분석하였다. 그리고 성인전담 단과대학 운영의 우수 사례로 미국 하버드대학과 시카고대학, 영국의 워릭대학을 선정하여 각 교육과정 구성과 운영 방법 등을 살펴보고, 이를 기초로 전문가 면담을 진행하여 성인전담 단과대학의 운영방안을 제안하였다. 그 결과 대학 조직개편의 운영철학으로 대학책무성과 정책적 효율성, 대학 특성화, 그리고 지속적이고 안정적 체제의 구축을 제시하고 다양한 입학진입트랙의 제공, 사전 준비교육과정의 제공을 통한 학습준비도의 확보, 선행학습인정 범위 및 방법, 전공과 수업방식, 학사제도 및 재정지원을 포함한 기타 성인학습자 맞춤형 서비스 등을 제안하였다.