• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.547-551
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• 1996

In this paper, robust vibration control of a one-link flexible robot arm based on variable structure system is discussed. We derive dynamic equations of it using a Lagrangian assumed modes method based on Bernoulli-Euler Beam theory. The optimal sliding surface is designed and the problem of chattering is also solved by the adoption of a continuous control law within a small neighborhood of the switching hyperplane.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.703-706
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• 1999

In this paper, robust vibration control of a one-link flexible robot arm based on variable structure system is discussed. We derive dynamic equations of it using a Lagragian assumed modes method based on Bernoulli-Euler beam theory. The optimal sliding surface is designed and the problem of chattering is also solved by the adoptation of a continuous control law within a small neighborhood of the switching hyperplane.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.451-456
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• 1990

We treat the problem of the robust tracking of a class of nonlinear systems which can be asymptotically decoupled in approximate sense by state variable feedback. A nonlinear control law is derived such that the tracking error in the closed loop system is uniformly bounded and tends to a certain small neighborhood of the origin. Simulation results show that simultaneous lateral and longitudinal maneuvers in airplane can be accurately performed in spite of uncertainty in stability derivatives.

• 대한전자공학회논문지
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• 제26권4호
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• pp.27-34
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• 1989

可變 構造 시스템 理論을 適用한 適應 모델 追從 制御器를 設計 하였다. 變形된 슬라이딩 모드 條件을 滿足시키는 提案된 制御器는 狀態 軌跡의 슬라이딩 平面 到達 速度를 改善하고 슬라이딩 모드에서 채터링의 크기를 줄이도록 한다. 슬라이딩 平面 近處의 領域에서 制御入力을 바꿈으로써 채터링을 줄이고 이 結果를 컴퓨터 시뮬레이션을 통하여 立證하였다.

• 보건행정학회지
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• 제21권2호
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• pp.329-348
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• 2011

This research analyzed 168,010 cases of death of the aged over 65 from 244,867cases of death excluding 7 unknown age cases from 244,874 all age cases of death by using the death data of the National Statistical Office for 2007 to figure out factors affecting the quality of causes of death statistics of the aged and to suggest the ways of improving the quality of death statistics of the aged in korea. This research tried to derive factors affecting ill-defined cause of death category in acordance with WHO's guidelines and to find causes of lowering the accuracy of causes of death statistics of the aged. This research identified the problems of causes of death statistics of the aged by using both demographic characteristics such as sex, age, marital status, educational attainment, residential region, region size and factors of death items as independent variable to find causes of ill-defined cause of death of the aged. Logistic regression analysis was executed to calculate the hazard ratio about the ill-defined causes of death of the aged and multiple regression analysis was conducted to derive factors affecting the ill-defined cause of death by regional groups through using these independent variables such as the component ratio of over age 65, female death rates, doctors insitutions rate, medical institutions rate, attaching rates of death certificate by neighborhood. As a results of this research, R-code was the highest of ill-defined causes of death, accounting for 82.1%, and senility death(R54) of R-code was the highest, accounting for 91.2%. through subdivided order distribution of the ill-defined causes of death of the aged. As ill-defined causes of death by regional groups, attaching rates of death certificate by neighborhood was the most important factor(p<0.05) and also showed regression model's description with 83.8% ($R^2$=83.8%). Furthermore, Jeon-nam was the highest in the regional groups and these regions such as Je-ju, Jeon-buk, Chung-nam were not only attaching the death certificate by neighborhood but also were high at the rate of ill-defined causes of death. Therefore, this research found that both reconsideration about death certificate by neighborhood and education for doctors who write death certificate were needed the most.

• 한국사회복지학
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• 제58권4호
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• pp.265-289
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• 2006

본 연구의 목적은 빈곤이 아동의 학구적 성취에 미치는 과정을 분석하는 것이다. 이를 위해, 한국청소년패널(초4패널) 1차년도 자료 2838사례가 활용되었으며, 구체적 분석방법은 구조방정식모형이 사용되었다. 분석결과, 빈곤은 아동의 학구적 성취에 직접적으로 영향을 미치는 것이 아니라, 가족기능, 이웃환경, 사교육, 자기 신뢰감 등 여러 과정변수를 통해 영향을 미치는 것으로 나타났다. 이러한 본 연구의 발견은 빈곤아동에 대한 사회적 지원이 학구적 성취 수준을 향상시키는데 기여할 수 있음을 보여주는 것이다. 특히, 이러한 사회적 지원이 빈곤의 영향을 매개하는 요인들에 집중될 필요가 있음을 보여준다.

• 대한가정학회지
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• 제45권7호
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• pp.71-91
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• 2007

We investigated the ecological variables of adolescent sexual behavior. We grouped the behaviors into organism, microsystem, mesosystem, and exosystem. The variables belonging to the organism group were sexual attitude, sex, grade, sexual knowledge, sexual education, dating experience, problem behaviors, and self-control. The microsystem variables included the parent-adolescent communication about sexuality, parental monitoring, parent educational background, friend relationships, and school environment. Moreover, the mesosystem variables included family-peer and family-school relationships. The exosystem variables were comprised of neighborhood environment and pornography. The study group included 369 adolescents from the first and second grade of several high school in Daegu, Korea. We found that the factors affecting adolescent sexual behavior included grade, sex, dating experience, self-control, smoking, and pursuing sexual pleasure. As well, contact with deviant friends, father-adolescent communication about sexuality, school type, and attachment to teacher. In addition the family-peer relationship also affected adolescent's sexual behaviors as well as pornography and neighborhood environment. Lastly the variable belonging to the organism group was found to have the greatest effect on adolescent, sexual behavior compared to the other variables.

• 한국자동차공학회논문집
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• 제8권6호
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• pp.142-155
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• 2000

A MIMO model reference control scheme incorporating the variable structure theory for a vehicle four wheel steering system(4WS) is proposed and evaluated for a class of continuous-time nonlinear dynamics with known or unknown uncertainties. The scheme employs an neural network to identify the plant systems, where the neural network estimates the nonlinear dynamics of the plant. By the Lyapunov direct method, the algorithm is proven to be globally stable, with tracking errors converging to the neighborhood of zero. The merits of this scheme is that the global system stability is guaranteed and it is not necessary to know the exact structure of the system. With the resulting identification model which contains the neural networks, it does not need higher degrees of freedom vehicle model than 3 degree of freedom model. Th proposed scheme is applied to the active four wheel system and shows the validity is used to investigate vehicle handing performances. In simulation of the J-turn maneuver, the reduction of yaw rate overshoot of a typical mid-size car improved by 30% compared to a two wheel steering system(2WS) case, resulting that the proposed scheme gives faster yaw rate response and smaller side angle than the 2WS case.

• 재활복지
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• 제21권1호
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• pp.71-95
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• 2017

본 연구는 노인의 장애유무가 성공적 노화에 미치는 영향과 사회적 관계망의 조절효과를 분석하여 장애가 있는 노인의 성공적 노화를 위한 사회복지 정책 및 실천적 함의를 제시하는데 목적이 있다. 연구대상은 국민노후보장패널조사(KReIS) 4차 개인조사 및 부가조사에 모두 응답한 대상자 중 만 65세 이상의 노인이며, 총 3,906명을 토대로 분석을 실시하였다. 자료 분석을 위해 IBM SPSS Statistics v23.0 프로그램을 활용하여 기술통계를 제시하고, 조절효과 분석을 위해 다중회귀분석을 수행하였다. 연구결과는 다음과 같다. 첫째, 노인의 장애는 성공적 노화에 부적(-) 영향을 미치는 것으로 확인되었다. 둘째, 사회적 관계망으로서 친구 이웃관계망과 가족관계망 모두 성공적 노화에 긍정적 영향을 미치는 것으로 나타났다. 셋째, 사회적 관계망 중 친구 이웃 관계망은 장애가 성공적 노화에 미치는 효과를 조절하는 것으로 나타났다. 즉, 노인이 장애가 있을수록 성공적 노화수준은 낮아지는데 친구 이웃 관계망의 사회적 지지가 커질수록 장애가 성공적 노화에 미치는 부적(-) 효과는 약해지는 것으로 나타났다. 이러한 분석 결과에 근거하여 장애가 있는 노인의 성공적 노화를 위해 장애노인을 대상으로 사례관리 도입과 사회적 관계망 확충을 위한 이동권 보장 및 자조모임 프로그램 제공 등을 제언하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 춘계학술대회 논문집
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• pp.131-136
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• 1997

This paper represent the variable structure adaptive mode control technique which is new approach to implement the robust control of industrial robot manipulator with external disturbances and parameter uncertainties. Sliding mode control is a well-known technique for robust control of uncertain nonlinear systems. The robustness of sliding model controllers can be shown in contiuous time, but digital implementation may not preserve robustness properties because the sampling process limits the existence of a true sliding mode. the sampling process often forces the trajectory to oscillate in the neighborhood of the sliding surface. Adaptive control technique is particularly well-suited to robot manipulators where dynamic model is highly complex and may contain unknown parameters. Adaptive control algorithm is designed by using the principle of the model reference adaptive control method based upon the hyperstability theory. The proposed control scheme has a simple sturcture is computationally fast and does not require knowledge of the complex dynamic model or the parameter values of the manipulator or the payload. Simulation results show that the proposed method not only improves the performance of the system but also reduces the chattering problem of sliding mode control, Consequently, it is expected that the new adaptive sliding mode control algorithm will be suited for various practical applications of industrial robot control system.