• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.3
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• pp.200-209
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• 2013

In this paper, the types of B-dot controller and the review results of B-dot controller stability are summarized. Also, it is confirmed that B-dot controller is very useful and essential tool when a dawn-dusk low earth orbit(LEO) large satellite has especially to capture the Sun for a required power supply in a reliable way after anomaly and that its algorithm is very simple for on-board implementation. New physical interpretation of B-dot controller is presented as a result of extensive theoretical investigation introducing the concept of transient control torque and steady state control torque. Also, the failure effect analysis results of magnetic torquers as well as a simulation verification are included. And the design recommendation for optimal design is provided to cope with the failure of magnetic torquer. Nonlinear simulation results are included to justify its capability as well as its performance for an application to a dawn-dusk LEO large satellite.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.504-510
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• 2011

In the culture performance field, device technologies for public performances with new concept is on the rise with the advancement of science. Most designers make use of the performance devices to achieve powerful and dramatic effect in their performances. It increases the perfection of performance. Most of all, applying high technology to performances' stage leads to enhance the space efficiency of the limited stage as well as to enable us to run a fully unmanned performance. This paper proposes a reconstructible electric block system for public performances' stage to heighten the fantastic stage effect variously.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.4
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• pp.315-320
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• 2010

To improve not only the basic performance but also the fail-safe performance, power consumption of the main landing gear for helicopters, a semi-active control landing gear using hybrid MR damper, was introduced in this paper. This damper of the configuration to install a permanent magnet in a electromagnet MR damper, was designed by the trade-off study on permanent magnet location and a magnet field analysis. Force control algorithm which keep the sum of air spring force and damping force at a specified value during landing, was used for the controller. The drop simulations using ADAMS Model for this semi-active control landing gear, were done. The improvement of the preceding performances as the result to evaluate the landing performance by the simulations, has been confirmed.

• Journal of Korean Elementary Science Education
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• v.22 no.2
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• pp.149-155
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• 2003

The objective of this research was to study the impact of metacognitive lesson models on the formation of magnetic field concepts. The subjects of this research was eighty students from two sixth grade classes. One class of forty of these students was the experimental group, which the metacognitive strategic lesson model was applied, and the other class of forty students was the control group which the traditional lessons were conducted. As the result of the experiment, the experimental group and the control group, which previously did not show difference in terms of achievement of conceptualizing magnetic field, displayed a significant difference. According to the comparison between the pre-experiment test on the students' previous concepts and the achievement of the students after the experiment, the middle group showed difference between the experimental group and the control group in a small degree. The lower group showed a notable difference between the two groups and the higher group showed no difference. In terms of achievements shown in different questions asked, there was little difference in the questions that were stated in the textbook while there was a significant difference in the questions that applied the contents of the textbook. The higher academic group, according to the test on the previous concepts, did not show much difference between the experimental group and the control group when they were asked about the concepts of the textbook. In terms of the comparison in the metacognitive levels, both the higher and lower metacognitive experimental groups' average grade was higher than the control groups' and showed an important statistical difference.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.362-362
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• 2023

한정된 수자원의 이용 및 관리로 매년 물 부족과 물 배분 의사결정 문제가 발생하고 있다. 50년간(1965~2014년) 수자원의 총량은 약 1.2배 증가한 반면 인구수 약 1.8배, 생·공·농업용수의 수요는 약 5배가 증가(국회입법조사처, 2018) 했을 뿐 아니라, 기후변화의 영향으로 인한 강수량의 변화와 지역별 편차가 커져 지속가능한 물관리 필요성이 증대되고 있다. 따라서 효율적인 물관리를 위해서는 관리부처가 분절되어 있는 물순환 계통의 데이터를 통합하는 것이 우선시되어야 하고 이를 통해 물순환 모니터링/평가/예측 기술을 개발할 수 있다. 본 연구에서는 생활용수 물순환 계통 통합 DB를 정의 및 구축하였다. 도시의 관점에서 물순환 시스템을 순차적으로 물 유입(수원~취수장)/전달(정수장~급수지역)/유출(하(폐)수처리장~방류구)의 개념으로 설정하고 DB정의서를 마련하였다. 연구대상지는 가뭄이 장기화가 되고 있는 전라남도중 물순환 계통이 비교적 단순한 네트워크로 형성되어 있는 함평군 도시지역으로 선정하였다. 연구 기간은 총 5년(2017년 1월 1일~2021년 12월 31일)이고 일 단위 실계측자료 위주의 원자료를 구축하였다. 이를 이상치 탐지, 제거, 대체의 과정을 거쳐 품질 보정하고 정제된 시계열 자료에 대한 특성 분석을 하였다. 그 결과, 물순환 계통 내 주요 지점 간의 상관관계 및 지연시간을 통한 물흐름의 시계열적 특성을 파악할 수 있었으며 모형의 적합도를 판단하는 데 활용되는 통계량과 유의미하지 않은 잔차의 자기상관성을 볼 때 물 유입-전달-유출의 단기 예측을 위한 ARIMA(Auto-regressive Integrated Moving Average) 모형의 구축도 가능할 것으로 판단되었다. 다만 여름철 발생하는 방류량의 첨두값을 설명하기 위해서는 강우에 의한 불명수 발생으로 증가하는 방류량을 묘사할 수있어야 하므로 향후에는 물순환계통 외 해당 지역의 불명수(강우 효과)도 하수 방류량의 주요 입력 요인으로 추가 검토할 필요가 있다.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.6
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• pp.11-26
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• 2016

Businesses have to survive and thrive in both domestic and international environments. In order to resolve these problems, new alternatives have been presented. These include the importance of women's resources and entrepreneurship of female CEOs. The sensibility, delicacy, creativity as well as the intuitive power of female CEOs, actively enables them to cope with the ever-changing environment. Because of the rapidly changing circumstances, the above mentions women's attributes are highlighted thus, causing women's roles in society to shift from their traditional tendencies to finding careers and their own identities. Due to this change in social roles, social interest and the values of female CEOs are being reevaluated. Accordingly, the conceptual consideration of female entrepreneurship (innovation, enterprise, risk sensitivity) as well as the factors to be considered for the entrepreneurship of female CEOs in order to promote knowledge management performance was derived in this research. The deducted implication of this research is that generally, the enterprise and risk sensitivity of entrepreneurship affect the knowledge management performance of female CEOs. It is therefore proved that in the case of female CEOs, entrepreneurship and self-efficacy are linked, allowing them to achieve the desired outcome for a specific task performance. Female CEOs are capable of company management through the mediating process of their enterprise, risk sensitivity, and self-efficacy and with faith in their knowledge management, will be able to achieve high performance. Therefore, using strengths and nature peculiar to women, women's economic activities derived from knowledge management based on entrepreneurship will not only help overcome the long-term economy crisis but also lead to high economic growth and development. This will be a dynamic force for the nation's new growth with financial means. The comparative study of existing results will also contribute in suggesting the direction of policies that will enable the success of female CEOs in entrepreneurship.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1119-1127
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• 2010

In this paper, the design and nonlinear simulation of a multistable electromagnetic microactuator, which provides four stable equilibrium positions within its operating range, have been discussed. Quadstable actuator motion has been made possible by using both X- and Y-directional bistable structures with snapping curved beams. Two pairs of the curved beams are attached to an inner frame in both X- and Y-directions to realize independent bistable behavior in each direction. For the actuation of the actuator at the micrometer scale, an electromagnetic actuation method in which Lorentz force is taken into consideration was used. By using this method, micrometer-stroke quadstability in a plane parallel to a substrate was possible. The feasibility of designing an actuator that can realize quadstable motion by using the electromagnetic actuation method has been thoroughly clarified by performing nonlinear static and dynamic analyses and electrothermal coupled-field analysis of the multistable microactuator.

• Cartoon and Animation Studies
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• s.44
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• pp.307-331
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• 2016

Webtoon is the most popular cultural contents representing contemporary Korea. This study explores the cultural aspects of participatory culture surrounding Webtoon, and reveals the cultural implications of webtoon in contemporary Korea. Particularly, this study notes that the engagement of the participatory culture is formed from the user-generated images and analyzes the reproduction patterns of them. Chapter 2 analyzes the mimicking process of user-generated images based on the 'meme' concept. Especially based on the variation degree of text or image, the user-generated images could be classified into three types of 'completely variant', 'partly variant', and 'completely same'. Users use these images as one of the fun factor by transplanting them into daily messenger conversation. Chapter 3 reveals the cultural meaning which is derived from the process of user-generated images creation. In particular, this study notes that most of the user-generated images are mimicking the main character of the original webtoon, and analyzes the underlying desire of the mass based on the literary theory of Northrop Frye. The main readers of webtoon are petit-bourgeois living in Korean metropolitan, and the user-generated images also reflects the daily lives of these ordinary people. User-generated images of webtoon are imitating the original contents in a way of replicating or mutating the images or texts. Also, they are consumed and enjoyed as an amusing code among users. Especially by mimicking the appearance of the main character in a self-reflective way, they appeal to day-to-day sympathy of users. In that user-generated images reveal the desire of the public living in contemporary Korea, this study examines the cultural implication of webtoon.

• 대한공업교육학회지
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• v.39 no.1
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• pp.23-46
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• 2014

The purpose of this study was to analyze the textbooks of career counseling which are written or translated in Korean so as to understand the usefulness and limitation on the usage of career counseling textbooks. Research questions are as follows: 1) what contents are included in textbooks of career counseling? 2) what are the differences of content rates among textbooks of career counseling? 10 textbooks of career counseling were analysed(6 textbooks: introduction to career counseling, 4 textbooks: focused on career counseling skills and techniques) based on the competency components for career counseling professionals presented by Yoo(2009). Results indicated that 1) 6 textbooks of introduction to career counseling have the most content of 'category1: theories and concepts related to career counseling'. In comparison, 4 textbooks focused on career counseling skills and techniques have the most content of 'category4: career counseling competency'. 2) Based on the unit of analysis chapter, the highest rates are 'category4: career counseling competency(33.33%)' and 'category1: theories and concepts related to career counseling(28.15%)'. 3) It is hard to find the contents related to the knowledge and skills of individual and group counseling(category 2), the competencies of network, problem solving, peer counselor feedback, administration, ethic(category 8,9,10,11,13), the growth and self-management as professionals(category 12,14).

• (The)Korea Educational Review
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• v.23 no.1
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• pp.113-138
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• 2017

Questions of why, what, and how represent the new perspective on goal construct. This paper proposed a novel approach toward the goal construct as a dynamic decision-making process. A number of researchers have agreed that goals initiate and sustain human motivation. In spite of the consistency in emphasis on goals, there are apparent inconsistencies in definitions of goal construct across theories and research. These inconsistences hinder interdisciplinary communication about goal construct, which in turn leads to jingle-jangle fallacy. Therefore, on the basis of systematic literature review, I defined the goal construct as a multifaceted and hierarchical decision-making process to structure desired end-states. The first process is generating goals, which can be also called "why" process. During this phase, individuals generate cognitive schema about general direction of desired end-states based on the conscious and nonconscious interpretation of subjective experience. The second process is goal setting, which can be called "what" process. Here, individuals clarify contents of multiple goals and structure hierarchy and priority of them. The last process is implementing goals, "how" process. This process contains decision making about whether he/she decides to implement the goal or not and how to execute goal-directed behaviors. In the last section of this paper, I tried to suggest several practical applications of this new perspective for adolescents, who struggle with why-what-how to have goals in learning context.