• 가정과삶의질연구
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• 제7권1호
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• pp.1-14
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• 1989

The purpose of this study was to identify the problems in the consumption life of household over the family life cycle so that they would support to select the consumer education subjects and the establish the long-term household plan. For these purposes, a survey was conducted using questionnaire. The data used in this study included 562 homemakers living in Seoul. Statistics used for data analysis were frequency distribution, Mean, Percentile, One-way Anova, Scheffie-test, Multiple Classification Analysis. Major findings were as follows; 1) In the level of the problems in the consumption life of household, housing problem, durable goods problem, healthy-medical problem and child education problem area were in the low level. Leisure problem and properties management problem area were in the high level. 2) The problems in the consumption life of household differed significantly over the family life cycle. 3) When controlling family monthly income and education level of husband was compared with not-controlling them, the influences of family life cycle on the problems in the consumption life were as follows. (1)At housing problem area, the effect of the FLC was higher in controlling them than not-controlling them. (2) At other problems the effects of the FLC was lower or same in controlling them than not-controlling them.

• 한국과학교육학회지
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• 제25권2호
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• pp.111-121
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• 2005

이 연구에서는 초등학교 6학년을 대상으로 변인통제 능력이 요구되는 문제해결 과정에서 실험설계와 증거제시의 특성 및 어려움을 분석하였다. 연구 결과 변인통제 문제 해결 과정에서의 실험설계 유형은 원인 변인과 통제 변인의 통제나 변화 여부에 따라 통제변인변화형, 원인변인통제형, 완전변인통제형, 불완전변인통제형, 모든변인변화형으로 구분되었으며, 실험설계 과정에서 선행신념에 포함된 원인 변인값을 포함시키려는 경향이 강하게 나타났다. 결론에 대한 증거제시 사례를 분석한 결과 원인변인의 변화 여부, 통제변인 통제 여부, 실험결과와 결론의 일치 여부에 따라 완전변인통제형, 원인변인통제형, 원인변인변화형으로 구분되었으며, 원인변인통제형이 가장 빈도가 높았다. 실험설계에 비해서 증거제시에서의 변인통제 정도는 훨씬 낮았는데, 이는 선행신념에 포함된 원인 변인값에 집착한 증거제시, 증거 실험에서의 실험 결과와 선행 신념의 불일치, 다중변인과제에 대한 잘못된 선입견 때문인 것으로 나타났다. 따라서, 선행신념을 극복할 수 있고, 탐구 과정 요소의 특성이 반영된 다양한 변인통제 발달 프로그램이 개발되어야 할 것이다.

• 로봇학회논문지
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• 제5권4호
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• pp.326-331
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• 2010

Marionette controlling robot has a problem that generates interference in rotation and intersection, therefore, the research on the independent shifter to move freely on the stage is required. Connecting omni-directional mobile robot with marionette controlling robot can solve this problem. Omni-directional mobile robot makes itself rotate and translate in 2D plane freely. Magnetic device is used to connect the moving part with the control part of the robot to minimize the intereference generated by the movement of robot. When robot moves, it can move to all directions with the suitalbe setting of banlance power. The moment of inertia is minimized by dividing the robot to the upper and lower parts in the marionette performance stage. Rotation and interference problem of independent omni-wheel Robot can be solved by using the permanent magnet. The efficiency and safety of the marionette controlling robot is proved by the experiment.

• 대한전기학회논문지
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• 제36권6호
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• pp.437-443
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• 1987

Due to the recent development of microprocessor, the digital control is now in use for the practical structure of the control systems, but it leaves the problem of controlling delays caused by computation time when it is applied to the realization problems, such as application method of the control law and controlling effect of continuous control, etc. This paper deals with robust stability of the digital regulator which compensates for the controlling delays by applying prediction values of state.

• 가정과삶의질연구
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• 제27권3호
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• pp.145-158
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• 2009

The purpose of this study was to investigate the effects of socio-demographic variables, family emotional environment and maternal discipline style on school children's emotional regulation. Subjects of this study consisted 953 elementary school students drawn from 4 elementary schools in Cheong-ju city and Cheongwon-gun. Data were analyzed by the methods frequency, percentage, Cronbach's ${\alpha}$, factor analysis, Pearson's correlation, and hierarchical regression using SPSSWIN 12.0 program. The results of this study were as follows: First, girls used greater problem-focused coping than boys did. Children in sixth grade used more problem-focused coping regulation compared to those in fourth grade. When children perceived higher level of family communication, emotional support, participation of family rituals, family worries, and parental conflict, they were more likely to use problem-focused coping. Additionally, both maternal supportive discipline and behavioral controlling discipline styles increased children's problem-focused coping. Second, girls presented greater emotional venting than boys did. Children in sixth grade expressed higher level of emotional venting compared to those in fourth grade. While family communication, family worries, and parental conflict increased children's emotional venting, family emotional support and participation of family rituals decreased it. Only mothers' psychological controlling discipline positively predicted children's emotional venting. Third, girls presented higher level of children's aggressive expression than boys did. The lower level of family support increased children's aggressive expression. Higher level of family worries and parental conflict increased it as well. Also, children's aggressive expression was positively predicted by mothers' psychological controlling discipline. Fourth, girls presented greater avoidance than boys did. Children in sixth grade expressed higher level of emotional avoidance compared to those in fourth grade. In family emotional environment, while family support lowered children's emotional avoidance, family worries and parental conflict increased it. Moreover, mothers' psychological and behavioral controlling discipline styles positively explained children's emotional avoidance. In conclusion, family emotional environment was the strongest factor to predict school children's emotional regulation among other variables.

• 유통과학연구
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• 제20권3호
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• pp.53-58
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• 2022

Purpose: Controlling and minority shareholders sometimes have conflicting interests. Controlling shareholders who do not have adequate monitoring can exhibit a strong tendency to maximize their personal wealth. In this case, cash holdings can be the easiest means for them to pursue their personal interests. This study examined whether the largest shareholder's ownership proportion affected the speed at which firms adjust their cash holdings to target levels in Korean distribution and service companies. Research design, data, and methodology: The study uses regression analysis to examine 834 firm-year samples listed on the KOSPI between 2013 and 2018 in the distribution and service sectors. Results: The largest shareholder's ownership is positively related to a firm's cash holdings adjustment speed. That is, the larger the largest shareholder's ownership, the faster the firm adjusts its cash holdings to achieve the target level. Conclusions: This study contributes to the literature by providing evidence that the cash holdings adjustment speed in Korean service and distribution companies is affected by the largest shareholder's ownership. As the agency problem between controlling and minority shareholders in Korea is a major issue, minority owners' sensitivity to agency costs may help restrict controlling owners' ability to maximize their personal wealth.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1858-1862
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• 2005

Stepping motor normally operates without feedback and may loss the synchronization. This problem can be prevented by using positional feedback. This paper introduces one method for closed loop control of stepping motor and a method for combining full-step control and micro-step control. This combination controlling apparatus can perform position control with high accuracy in a high speed, so that it will not suffer from vibration (or hunting) problem when stopping motor. Controlling apparatus contains a position counter block for detecting rotor position of stepping motor, a driving block for supplying current to windings of stepping motor, a control block for comparing output signal of position counter block with command position (desired position) and outputting current command signal based on deviation between current position and command position of rotor. To output current command signal, the control block refers to a sine wave data table. This table contains value of duty cycle of Pulse Width Modulation signal. As the second object of this paper, the process of building this data table is also presented.

• ETRI Journal
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• 제5권2호
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• pp.17-28
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• 1983

This paper deals with the problem of optimally controlling traffic flows in urban transportation traffic networks. For this, a nonlinear discrete-time model of urban traffic network is first suggested in order to handle the phenomenon of traffic flows such as oversaturatedness and/or undersaturatedness. Then an optimal control problem is formulated and a hierarchical optimization technique is applied, which is based upon a prediction-type two-level method of Hirvonen and Hakkala.

• 한국과학교육학회지
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• 제13권2호
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• pp.152-162
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• 1993

The high school students' problem solving patterns and their features in scientific inquiry, especially on controlling variables and stating hypothesis have been investigated. The 8 problems on controlling variables and stating hypothesis were selected out of the scientific inquiry area in the experimental tryout of Aptitude Assessment for College Education, and had been used to find the patterns and their features. The results of findings are as follows: There were seven patterns in the process of solving problems. Five of seven patterns were found in right answers and four patterns in wrong answers. Two patterns were found in both right and wrong answers. Some students could solve the problems even though they did not understand the elements of the scientific inquiry, controlling variables and stating hypothesis. The false application of physics concepts, misunderstanding about the elements of the scientific inquiry and using unrelated experience and conjectures were the features of students' wrong answers. On the other hand, the right application of physics concepts, understanding and applying the elements right, infering answers from the tables and figures on statements of suggested problems were the features of right answers. The further studies on this kind may helpful to find the higher mental abilities related to scientific inquiry and to develop tools for testing students' scientific inquiry thinking skills.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.249-252
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• 1997

In this paper the sway-control problem of a container crane is investigated in the perspective of controlling an underactuated mechanical system. For fast loading/unloading of containers from the ship, quick suppression of the remaining swing motion of the container at the end of each trolley stroke is crucial. Known nonlinearities are fully incorporated by feedback linearization. Robustness is enhanced by variable structure control. Compared with the linear LQ control, much better performance can be obtained.