블럭펄스 함수를 이용한 대규모시스템의 계층별 상태추적에 관한 연구

안비오,임윤식,김정환,안두수 成均館大學校 科學技術硏究所 1996 論文集 Vol.47 No.1

This paper presents a algorithm of hierarchical approach to tracking problems for large-scale systems via Block pulse functions(BPF). In controlling the n-th order large-scale systems for tracking problem, two point boundary value problems(TPBVP) has the 2n-th order. Generally, it is very difficult to obtain the solutions due to its high order. In order to solve the this difficulty, hierarchical approach is proposed. And apply the BPF transformation to the system, we simply obtained the solutions of decomposed control laws from the recursive algebraic equations.

축소 플랜트를 이용한 PID 제어기 설계

안두수,임윤식,김민형,이재춘,이한석 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.1

In this paper, a simple method is developed for desiging a single loop PID contriller using a computer oriented algebraic approach which is based on general polynomial. Specifically, the proposed PID controller can approximately achieve an arbitrarily specified closed-loop response, which satisfies time domain specifications such as rising time, overshoot and settling time. The design technique is straightforward, and the paramaters of the PID controller are determined by solving a set of linear equations using the least squares method. It does not involve any trial and error proceduer, hence the difficulty of the conventional approach can be avoided.

수공구조물이 하천환경에 미치는 영향에 관한 연구(II) : 수질 및 생태학적특성 Water Quality and Ecological Characteristics

안승섭,최윤영,이수식 한국환경과학회 2002 한국환경과학회지 Vol.11 No.4

In this study, water protection reservoir is selected as the target which is located at the estuary of Taehwa river to analyze and examine the effects of hydraulic structure on river environment. This study examined the water quality variation characteristics among many effects of hydraulic structure on river environment before and after removal of the sediment protection reservoir when low flow is yielded. This study aims at the definition of factors which cause the change of ecological environmental friendly river space development through the comparison of stream variation conditions(depth, velocity, and etc.) and riverbed variation characteristics with ecological depth condition of Taehwa-river's channel for each representative species of fish and examination those. Firstly, form the examination result of water quality when low flow is yielded before and after removal of the sediment protection reservoir for problems about water quality of river due to flow amount decrease in river, it is found that DO decreases about 0.78~0.86ppm at the lower stream of Myeongchon-gyo, and BOD decreases about 0.06~0.24ppm from right upper stream to the direction of estuary when the sediment protection reservoir is removed. It is known from the above that there is some improvement of water quality from the lower stream of Taehwa-gyo to the estuary in case of removal the sediment protection reservoir. Nextly, it is thought that the effects on ecosystem due to water depth and draw down in channel is not serious on the basis of the examination of water quality analysis result according to removal of sediment protection reservoir and hydraulic depths for reservation of ecosystem, these are 10~40㎝ for breeding season, 10~50㎝ for fry period, and 10~100㎝ for adult period of the representative species of fish in Korea.

수공구조물이 하천환경에 미치는 영향에 관한 연구(I) : 수리학적특성 Hydraulic Characteristics

안승섭,최윤영,이수식 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

In this study, water protection reservoir is selected as the target which is located at the estuary of Teahwa river to analyze and examine the effects of hydraulic structure on river environment. This study aims at the definition of factors which cause the change of ecological environment of river due to the effects of the sediment protection reservoir, and the proposal of the direction of environmental friendly river space development through the analysis and examination of stream variation conditions and riverbed variation characteristics among many effects of hydraulic structure on river environment before and after removal of the sediment protection reservoir when design flow is yielded. Firstly, in case of removal the existing sediment protection reservoir, the hydraulic variation characteristics like depth drop due to removal of the sediment protection reservoir are thought of little because it is examined that depths drop with about 0.01m and 0.01~0.56m when low flow is yielded and design flood yielded, respectively. Nextly, as the examination result of the variation characteristics of flow velocity in case of removal the existing sediment protection reservoir, it is thought that the concern about riverbed erosion is not serious according to the analyzed result as the mean velocity of the channel section where the velocity varies in case of removal the sediment protection reservoir is about 0.07~1.36m/s when low flow is yielded, and is about 1.02~2.41m/s when design flood is yielded despite riverbed erosion is concerned as it is examined that flow velocity is getting increase as about 0.01m/s when low flow is yielded and about 0.01~0.44m/s when design flood is yielded. Lastly, from the prediction result of riverbed variation for each flow amount condition before and after removal the sediment protection reservoir, it is known that the variation range of riverbed is nearly constant when flow amount of the channel exceeds a specific limit as it is analyzed that the more flow amount, the more erosion and sediment in the channel section of down stream part of the sediment protection reservoir and the sediment protection reservoir-Samho-gyo, and the variation ranges according to flow amount between flood condition and design flood condition have little difference in the channel section of the upstream of Samho-gyo.

편측 상하지 마비를 동반한 두개강내 지주막 낭종1례

안상윤,김영태,이하백,문수지 한국의학사 1989 診斷과治療 Vol.9 No.8

K대학 치위생과 재학생의 학과만족도 조사 연구

송윤신,권순복,안금선,김영남,김수화,차민주 경복대학 2003 京福論叢 Vol.7 No.-

경기 K대학 치위생과 재학생들의 대학 진학시 학과선택 요인을 알아보고, 학과 만족도를 분석하여 치위생과 학과 경쟁력을 높이고 학생지도의 기초자료를 제공하고자 한다. 치위생과 입학 결정시 영향을 준 요인으로는 전반적으로 본인이 가장 높게 나타났으나 학년별로는 2학년이 77.5%로 가장 높았으며, 치위생과 선택이유로는 취업보장, 주위권유, 적성·흥미 순으로 조사되었다. 치위생과 학과만족도에서 강의실환경에 대해서는 전체 조사대상자 중 9.4%가 만족하다고 응답했고, 실험·실습기자재는 36.0%가 만족한다고 응답하였으며, 학우관계에서는 74.0%, 학과지도방침 38.9%, 치과위생사 직업만족도는 79.4%가 만족하고 있었다. 특히 조사대상자 중 다른 학년보다 2학년 학생들에게서 직업만족도를 제외한 다른 항목의 만족도가 가장 높게 나타나고 있다. 직업만족도는 1학년이 85.4%로 가장 높게 조사되었다. 휴학·자퇴를 고려한 경험유무에 대한 질문에서는 있다고 응답한 학생이 47.8%이었으며, 그 이유로 1학년은 경제적이유를, 2, 3학년은 적성이라고 응답하였다. 입학결정요인과 만족도와의 관계에서는 본인이 입학을 결정했을 때 재학만족도, 직업만족도, 학과지도방침, 전임교수에 만족한다고 응답한 경우가 가장 많았으며 진로계획에서는 취업이 가장 높았다. 학우관계와 만족도와의 관계에서는 학우관계에 만족한다고 응답한 경우 재학만족도, 직업만족도, 학과지도방침에 대한 만족도가 높은 것으로 분석되었다. 구강보건교육이 치위생과 선택에 미친 영향력에 대한 조사에서는 학년별 유의성은 보이지 않았으나, 전체조사대상 중 89.5%가 영향력이 보통이상이라고 응답해 높은 비율을 차지하는 것으로 나타났다. The purpose of this study is to identify the factors affecting selection of a major and the department satisfaction for improving the competitiveness of the dental hygiene department and providing the data for students guidance. The most influential person and factor in selecting a major is the person oneself(77.5% of the second-year students responded to the question) and the percentage of employment. The reaction of satisfaction with the classroom and practice facility indicates 9.4% and 36.0% in favor. 74.0% of surveyees is satisfied with classmates. In satisfaction with a course of department and profession, 38.9% and 79.4% of respondents answer in the affirmative. The second-year students of the respondents shows higher rate than other grades in .satisfaction with items above, except the satisfaction with profession. It appears that the freshman answered the most in that question. From the survey related to the experience of thinking over temporary absence from school or voluntary resignation, 47.8% of surveyees responded they had experienced thinking about that. The freshman answered the reason is financial difficulty and the second- and third-year students selected an aptitude. In the correlation coefficient of determinants for selection of college with the department satisfaction, when the determinant is oneself, the satisfaction with being at college, profession, a course of department, and teaching staff is high. In the correlation coefficient of classmates with department satisfaction, the students responding in the affirmative on classmate satisfaction had a high degree of satisfaction with being at college, profession, and a course of department. The experience of oral health education is not statically significant by grades to select the major, but 89.5% of the students majoring dental hygiene at K-college responded over average.

BPF를 이용한 시변 확률 시스템의 제어기 설계

임윤식,이명규,안두수 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1

The orthogonal function has been widely employed to solve the control problems, whereas its application to solve the LQG prroblem has hardely been used. Chang & Lee suggested direct application of orthogonal function to Riccatti equation and covariance matrix Riccatti equation. But in this method, the dimension of the integration operational matrix enlarge as the order of the system or the number of expansion term increases. In this paper, in order to solving Riccatti equation and covariance matrix Riccatti equation, TPBVP and matrix fraction method are used. LQG controller is designed by applying block pulse function to this method.

블럭펄스 함수를 이용한 비선형 확률 시스템의 제어기 설계

임윤식,정제욱,안두수 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.2

The purpose of this paper is to indicate how the available thoery of optimal control and estimation for the so called linear-quadratic-Gaussian(LQG) problem provides such a unified design procedure for the nonlinear system. In particular, we wish to stress the advantages of this method from the viewpoint of ease of computation, since the theory provides us with equation that can be readily solved by modern digital computers. This algorithm minimizes the effect for the initial error by adaptive analysis method via BPF and the each sampling interval of the nonlinear system is linearized using BPF's coefficients, the convergence of the estimated states can be improved.

블럭펄스 함수를 이용한 확률동적 시스템의 상태추정

임윤식,안비오,안두수 成均館大學校 科學技術硏究所 1996 論文集 Vol.47 No.1

This paper presents a method to design Kalman filter on continuous stochastic dynamical systems via BPF(block pulse functions). When we design Kalman filter , minimum error variance matrix is appeared as a form of nonlinear matrix differential equations. Such equations are very difficult to obtain the solutions. Therefore, in this paper, we simply obtain the solutions of nonlinear matrix differential equations from recursive algebraic equations using BPF. We believe that the presented method is very attractive and proper to the states estimation on continuous stochastic dynamical systems

마이크로 엔드밀링에서 음향방출 신호를 이용한 상태감시

정연식,강익수,김전하,강명창,김정석,안중환 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

Ultraprecision machining and MEMS technology have been taken more and more important position in machining of microparts. Micro endmilling is one of the prominent technology that has wide spectrum of application field ranging from macro parts to micro products. Also, the method of micro-grooving using micro endmilling is used widely owing to many merit, but has problems of precision and quality of products due to tool wear and tool fracture. This investigation deals with state monitoring using acoustic emission(AE) signal in the micro-grooving. Characteristic evaluation of AE raw signal, AE hit and frequency analysis for state monitoring is also presented in the paper.