• 대한조선학회논문집
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• 제48권1호
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• pp.8-14
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• 2011

RIB(Rigid Inflatable Boat) is widely used for coastal transportation in the commercial use and for ISR(Intelligence, Surveillance, Reconnaissance) in the military use. Since RIB is around 10 meters in length and over 30 knots in speed, its motion characteristics in waves is quite different from a large scale ship. When it turns, large roll occurs and heeling direction is opposite to the large ship's case. Currently, many countries are developing USV(Unmanned Surface Vehicle) of which type is RIB. In order to develop high performance autopilot and way point controller, it is very important to identify RIB's motion characteristics. In this paper, sea trial test results of a 7-meter RIB such as speed, turning, zig-zag, and way point control tests were represented and its resistance and propulsion model was identified by using sea trial data and Savitsky's formula. In addition, the state space model which will be used in the identification of the four-degree-of-freedom dynamics in the next step was formulated and the identification procedure was proposed.

• 보건행정학회지
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• 제14권1호
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• pp.1-23
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• 2004

This study was carried out to investigate the activities and job satisfaction of public health doctors in charge of community health programmes. Subjects were 138 public health doctors charged with community health project, registered in the roll of public health doctors, made out by Central Supporting Team for the District Health Work in 2002. Data was obtained from Ninety-six public health doctors. The response rate was 70%. The survey was conducted from March to April in 2003 bye-mail. The items of the questionnaire consisted of general characteristics of participants, understanding of their activities, support system, job satisfaction, and suggestions to improve the system. Collected data was analyzed using PC-SPSS 10.1. Descriptive analysis, t-test, and ANOVA test were used. The results are as follows: Most of the respondents showed a low participation rate in community health services, but they agreed to the importance of their activities and the necessity to modify and improve the system. 70% of the respondents were dissatisfied with their jobs. The participation in health planning and programmes of health center, and the degree of acceptance of their opinion from health center workers were significantly related to their job satisfaction. The participation rate of the public health doctors having specialty, in community health services is higher than that of the others. In terms of the supports for system operation, the reflection of one's intention in job arrangement process, education and public relation of this system, and the administrative and financial supports made significant differences in the job satisfaction and the accomplishment of their duty. The respondents hoped that the administrative and financial supports for public health doctors in charge of community health programmes should be reinforced to motivate them. They also wanted that they could keep from being overloaded with clinical services. They favored to conduct home visit, community diagnosis, health planning, and health promotion programs as their appropriate activities. From these results, we suggest some strategies to motivate and empower the public health doctors in charge of community health programmes.

• 한국컴퓨터정보학회지
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• 제11권1호
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• pp.9-17
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• 2003

우리나라에서도 정보통신부는 국가 및 공공기관의 전산망 품질수준을 제고하고 효율적인 정보시스템 구축을 지원하기 위해 공공부문 정보화사업에 대한 감리 제도의 활성화, 정보시스템 감리 자격제 도입, 민간 감리 기관의 육성 등을 주요 내용으로 하는 $\ulcorner$정보시스템 감리 제도 도입계획$\lrcorner$ 을 마련해 본격 시행에 들어가기로 했다. 정통부가 이번에 정보시스템 감리제도를 크게 강화하기로 한 것은 최근 들어 국가 및 공공기관을 중심으로 정보시스템 분야의 감리 수요가 폭발적으로 증가하고 있음에도 불구하고 한국전산원에 감리 업무가 집중되고 있어 공공부문의 감리 수요를 충족시키기 힘든 데다 국가정보화 사업에 대한 감리 제도의 도입 필요성이 점차 높아지고 있기 때문으로 풀이된다. 정통부는 감리제도를 활성화하기 위해 공공부문 정보시스템 감리를 정보화사업과 연계해 제도화한다는 방침을 세우고 공공부문 정보화사업에 대한 감리를 주관기관의 판단에 일임하되 정보화 추진위원회가 정한 국가적인 중요 사업에 대해선 감리를 의무화하기로 했다. 이에 대해 내. 외부 감사중 내부감사에 대해 그 내용을 파악해 보자는 데 그 목적이 있다.

• 한국항행학회논문지
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• 제9권1호
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• pp.19-27
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• 2005

인공위성이나 무인기와 같은 이동체와 지속적인 통신을 위해서는 최소한 2축 이상의 안테나 시스템이 필요하다. 또한 안테나가 차량, 선박 등의 이동체에 탑재될 경우 이동체의 롤, 피치, 요 모션의 영향을 상쇄시킬 수 있는 안정화 시스템(Stabilization System)과 이동하는 추적 대상 이동체를 연속적으로 지향할 수 있는 추적 시스템(Tracking System)이 갖추어져야한다. 이동체 안정화 및 추적 시스템의 성능은 안테나 Pedestal을 구동하는 서보제어시스템에 주로 의존한다고 할 수 있다. 따라서 본 논문에서는 Fuzzy-PID 제어기를 이용하여 2축 안테나 시스템의 안정화와 이동체 추적시스템을 위한 제어기를 구성하여 그 성능을 검증하였다. 설계한 안테나 서보제어 시스템의 검증을 위해, 같은 PID 게인으로 설계한 일반적인 PID 제어기와 Fuzzy-PID 제어기의 성능을 비교하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1787-1790
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• 2005

We have developed satellite devices for fine attitude control of the Science & Technology Satellite-2 (STSAT-2) scheduled to be launched in 2007. The analog sun sensors which have been continuously developed since the 1990s are not adequate for satellites which require fine attitude control system. From the mission requirements of STSAT-2, a compact, fast and fine digital sensor was proposed. The test of the fine attitude determination for the pitch and roll axis, though the main mission of STSAT-2, will be performed by the newly developed FDSS. The FDSS use a CMOS image sensor and has an accuracy of less than 0.01degrees, an update rate of 20Hz and a weight of less than 800g. A pinhole-type aperture is substituted for the optical lens to minimize the weight while maintaining sensor accuracy by a rigorous centroid algorithm. The target process speed is obtained by utilizing the Field Programmable Gate Array (FPGA) in acquiring images from the CMOS sensor, and storing and processing the data. This paper also describes the analysis of the optical performance for the proper aperture selection and the most effective centroid algorithm.

• Bulletin of the Korean Chemical Society
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• 제29권10호
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• pp.1937-1940
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• 2008

The P1 duplex of Tetrahymena group I ribozyme is the important system for studying the conformational changes in folding of ribozyme. The formation of the P1 duplex between IGS and substrate RNA and the catalytic activity of ribozyme require a variety of metal ions such as $Mg^{2+}$ and $Mn^{2+}$. In order to investigate the effect of the $Mg^{2+}$ concentration on the conformation of the P1 duplex, the NMR study was performed as a function of $Mg^{2+}$ concentration. This study revealed that the less stable AU-rich region formed duplex at $50{^{\circ}C}$ under high $Mg^{2+}$ concentration condition but melts out under low $Mg^{2+}$ concentration condition. It was also found that in the active conformation under 10 mM $MgCl_2$ condition, the unstable central G${\cdot}$U wobble pair maintains the significant base pairing up to $50{^{\circ}C}$. This study provides the information of the unique feature of the P1 duplex structure and the roll of $Mg^{2+}$ ion on the formation of the active conformation.

• 대한기계학회논문집
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• 제11권5호
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• pp.837-845
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• 1987

본 연구에서는 Tozawa의 이와 같은 근사적 3차원 해석법을 검토하여 그 특징 을 살피고 판나비, 판두께, 압하율의 변화가 삼차원변형역과 평면변형역의 최적 경계 면 위치에 미치는 영향을 고찰하고자 한다.

• 한국추진공학회지
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• 제20권1호
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• pp.76-81
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• 2016

부력을 이용한 연료공급밸브는 고속 비행체의 가압식 연료탱크 내 연료가 역 중력 상태에서 한 방향으로 이동하는 것을 쫓아 유로를 열어주어 지속적으로 흐르게 한다. 가혹한 시험조건과 고비용 등의 문제로 이 연료공급밸브를 실제 고속으로 시험하는 것은 쉽지 않은 일이다. 따라서 본 연구는 고속 시험 전에 저속항공기에 탑재해 기본적인 회전기동 및 역중력 시험(Negative-g test)을 수행한 내용을 포함하고 있다. 시험 결과를 바탕으로 각 기동에서 밸브의 작동 특성을 파악하고 분석하였다.

• 패션비즈니스
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• 제10권4호
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• pp.114-129
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• 2006

This purpose of this study is to research on the influence on the creation of young generation's street fashion of pop stars focused on pop music given the fact that fashion can be created by popular culture in this multi-media era. Also, this study is to provide useful data for the activation of the creation of young fashion culture and the fashion industry through pop stars' fashion. The pop stars' fashion that has affected young street fashion is as follows : Elvis Presley's rock'n'roll style, Beatles' mods style, Janis Joplin's hippy style, Sex Pistols's punk style, Madonna's boy-toy and corset style, Michael Jackson's androgynous style, Puff Daddy and L.L Cool J's hip-hop style, Bob Marley's reggae style, Spice Girls, Jennifer Lopez and Britney Spears's sexy style. The young street fashion culture of pop stars and its industrial meaning withdrawn from the above are as follows : Creation of a fashion icon, Creation of anti-fashion, Liberation of a sex role, Costume play culture, Activation of the young fashion industry through star marketing.

• International Journal of Ocean System Engineering
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• 제1권4호
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• pp.222-229
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• 2011

In this paper, we present the concept and main mission of the Crabster, an underwater walking robot. The main focus is on the modeling of drag and lift forces on the legs of the robot, which comprise the main difference in dynamic characteristics between on-land and underwater robots. Drag and lift forces acting on the underwater link are described as a function of the relative velocity of the link with respect to the fluid using the strip theory. Using the translational velocity of the link as the rotational velocity of the joint, we describe the drag force as a function of joint variables. Generalized drag torque is successfully derived from the drag force as a function of generalized variables and its first derivative, even though the arm has a roll joint and twist angles between the joints. To verify the proposed model, we conducted drag torque simulations using a simple Selective Compliant Articulated Robot Arm.