DESIGN OF A DISC-ON-DISC-TYPE CNC TRIBOMETER TARGETED AT DRY CLUTCH FRICTION PLATE WEAR CHARACTERIZATION

Matija Hoić,Mario Hrgetić,Nenad Kranjčević,Milan Kostelac,Joško Deur,Andreas Tissot 한국자동차공학회 2022 International journal of automotive technology Vol.23 No.1

The paper presents design of a disc-on-disc-type CNC (Computer Numerical Control) tribometer aimed at experimental characterization of friction and wear behaviors of automotive dry clutches. The torque or ormal force, slip speed, friction interface temperature, and closing time are accurately controlled during tests by employing rotational- and vertical-axis servodrives and a water-cooling system built in both axes. A compact two-axial piezoelectric torque and force sensor is built in between the vertical-axis spindle and the pressure plate, in order to provide direct measurements of friction torque and normal force. The slip speed is sensed by using an encoder placed at the rotating table that carries the friction plate. The disc temperature is controlled by means of imposing a delay between two consecutive clutch closing cycles, variable cooling pump speed, and a valve that can bypass the coolant flow around the pressure plate. The torque control ystem is realized in a cascade structure including inner normal force and vertical axis speed controllers. The closing time is controlled by means of “electrical inertia” implemented through rotational-axis servomotor torque control. The tribometer performances are demonstrated through a study of dry clutch friction plate wear rate characterization.

Thomas Hardy의 The Mayor of Casterbridge에 관한 연구

金會珍 서울市立大學校 1994 論文集 Vol.28 No.-

This paper is intended as an investigation of human ambivalence and Henchard's psychoanalysis, that is, his tragedy founded on the basis of ambivalence, and Hardy's view of fate. Thomas Hardy's tragic literature can accomodate a world of contrasting elements, It is the result of his attitude towards life which was one of "Life offers-to deny". Most of his works consist of the contrasting realities of tradition and modernism. His novels compared to the pastoral ones can be applicable to the former and his technique to the latter. The dual aspect of his novels can be replaced with realism and fantasy. They are found in the descriptions of Norcombe Hill in Far from the Madding Crowd, Egdon Heath in The Return of the Native and Casterbridge in The Mayor of Casterbridge. Hardy's view of fate can be taken as another example. We see that under the transition period between an old and new world his modernism is a reflection of his ambivalence. These two contrasting elements are presented as the main sources of his ambivalent literature. In The Mayor of Casterbridge Henchard's dual personality is revealed through his character and action, and the character and any given situation. To Henchard's tragedy Hardy applied Novalis' aphorism, "Character is Fate".

시간지연을 갖는 불안정한 플랜트에 대한 3요소 PID제어기의 설계에 관한 연구

정희범 순천대학교 공업기술연구소 1998 工業技術硏究所論文集 Vol.12 No.-

In this study, the synthesis of three-element PID controller for an open-loop unstable plant with time delay is proposed. Control problem such as stabilizing an open-loop unstable plant, servo-tracking, and disturbance rejection can be treated independently by each element of the controller. Tuning rules for each element of the controller are based on the loop gain and phase criterion of root loci, the internal model controller, and feed forward controller design method. The performance of the proposed controller was presented by computer simulations of example problems.

代理母契約의 實態 및 私法上의 問題點

이회규 강남대학교 사회과학연구소 1996 사회과학논총 Vol.2 No.-

입력-제한 시스템을 위한 자기동조 제어 알고리즘의 개발

정회범 순천대학교 공업기술연구소 1991 工業技術硏究所論文集 Vol.5 No.-

Self-tuning control algorithm for an input-constrained systems is developed and implemented in this study. Magnitude of control input for small motors is generally restricted to low level due to actuator saturation. The bounded-gain control algorithm proposed in this study yields smoother control input within the magnitude constraints comparing with the existing Clarke's suboptimal control algorithm. In the proposed algorithm, the system output responds fast at the expense of smoothness of input variation, as the weighting factor is increased. For the DC servo motor control, the system performance of the proposed algorithm is compared with that of the existing algorithm by computer simulation and experiment. The control programs are written in 8086 & 8087 assembly languages for real-time control. The output responses of both algorithms are similar, but smoothness of input variation using the proposed algorithm is verified.

정신연습이 매트운동의 기능향상에 미치는 영향

정회경,박찬홍 公州大學校스포츠科學硏究所 1998 스포츠科學硏究所論文集 Vol.- No.12

In this study it was dealt how many effects mental practice made on improving a cartwheel skill in gymnastics. As an experiment, eighty students chosen at random from four classes of C high school were divided into four groups and the first group did physical practice, the second group did mental practice the third did mental and physical practice and the fourth did controlled practice twice a week for eight weeks. As a result of this study it was show that when preliminary test was given, there were not meaningful differences among these groups and after that I came to know that in a post-test physical and mental practice had an effect on developing the skill of gymnastics ( turning cartwheels with hands on the floor) and when especially physical and mental practice were carried out together, the effect was increased. This study shows that 1. mental practice has an effect on developing the skill in gymnastics (turning cartwheels with hands on the floor). 2. when physical practice and mental practice are carried out together, though there is not a meaningful difference, it is more effective than when only physical practice is given. 3. when physical practice and mental practice are carried out together, its effect is more increased than when only mental practice is given.

代理人의 權限濫用과 相對方保護에 관한 小考

李會圭 강남대학교 사회과학연구소 1997 사회과학논총 Vol.3 No.-

추적조사를 중심으로 한 腰椎間板脫出症에 대한 蜈蚣藥鍼의 臨床的 硏究

최회강,소기숙,고강훈,박소영,김성남,이종덕,원경숙,문형철,김성철 大韓鍼灸學會 2003 대한침구의학회지 Vol.20 No.3

Objective : This study is performed for the purpose of examining the efficacy of the scolopendrid(Scolopendra morsitans L) which has been to low back pain as a folk remedy. Methods & Results : Seventy patints with H.I.V.D. treated with the scolopendrid aquacupuncture and examined 4 tests; D.I.T.I., physical test, Oswestry disability index, and self-conscious pain rate were studied. And we follow up after discharge, we evaluated the present state and recovery period. Or we evaluated by herniated type and duration of onset. There was 58~97% of efficacy rate in each tests. Moreover, statistically valuable change in all 7D.I.T.I. points and in disability index and in self-conscious pain rate was showed. Conclusion : The scolopendrid aquacupuncture is possible to be effective terating the H.I.V.D patients. so we suggest the possibility using this new remedy to the H.I.V.D. patients.

학급차원의 확장된 스킬스트리밍 교수가 정서·행동장애 위험 유아의 사회성 기술, 문제행동, 일반유아와의 상호작용에 미치는 영향

문회원,박지연 이화여자대학교 특수교육연구소 2014 특수교육 Vol.13 No.1

The purpose of this study is to examine the effects of class-wide implementation of enhanced skillstreaming on social skill, problem behaviors, and interactions with peers in young children at risk for emotional and behavioral disorders. The participants of the study were 24 children at risk for emotional and behavioral disorders who were attending 4 daycare facilities located in Seoul, Incheon, and Chungnam. Because the enhanced skillstreaming was conducted in class-wide format, the teachers of the participants and their peers also participated in the intervention. It took about 7 months to conduct this experiment including intervention preparation, pretest, intervention, posttest. Using pretest-posttest control group design, two independent t-tests were used to see if there was any difference between two groups in the dependent variables. As a result, significant differences were found between groups in social skill, problem behavior, and interaction with peers. Finally, discussions of the results, limitations of the study, and implications for future studies were suggested. Key Words : Skillstreaming, Young Children at Risk for Emotional and Behavioral Disorder, Social Skill, Problem Behaviors, Interaction. 본 연구에서는 확장된 스킬스트리밍(skillstreaming) 교수를 학급차원으로 적용하고, 이것이 각 학급에 통합된 정서·행동장애 위험 유아의 사회성 기술, 문제행동, 일반유아와의 상호작용에 미치는 영향을 알아보고자 하였다. 본 연구의 대상은 서울, 인천, 충남 지역에 위치한 4개 어린이집에 재원 중인 24명의 정서·행동장애 위험 유아로, 실험집단과 통제집단에 각각 12명씩을 배치하였다. 실험은 중재 준비, 사전검사, 중재, 사후검사의 순으로 7개월에 걸쳐 진행되었으며, 실험집단 유아가 속한 학급에는 스킬스트리밍 교수의 4가지 전략단계 및 9가지 실행단계를 충실하게 적용하는 동시에 연구자가 개발한 토막만화형식의 상황이야기 적용, 대집단과 소집단, 다시 대집단으로 이루어진 확장된 스킬스트리밍 교수가 제공되었다. 중재의 효과를 알아보기 위해 한국 유아 사회성 기술 검사, 유아행동 평가 척도, 또래 놀이행동 척도를 이용한 중재 전과 중재 후의 측정 결과에 대해 두 독립표본 t 검정을 실시하였다. 연구결과, 모든 종속변인에서 실험집단의 변화정도가 통제집단의 변화정도보다 유의하게 큰 것으로 나타났다. 마지막으로 연구결과에 대한 논의, 연구의 제한점, 후속연구를 위한 제언을 제시하였다.

중국어문학연구자의 중국전문가로서의 사회적 역할 : 유관 저술의 현황과 문제를 중심으로

梁會錫 韓國中國語文學會 2003 中國文學 Vol.40 No.-