• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.878-883
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• 1990

There have been many approaches to solve the disturbance rejection problem in the control of LTI systems with state independent disturbances or possibly nonlinear state dependent disturbances. From the view point of each actuator, robot manipulators can be modeled as the second class of systems. With this model, M.Nakao et al. [1] introduced a decentralized control scheme based on interference estimation which is simple in its implementation and robust to the coupled dynamics and parameter variations. This paper systematically generalizes the control scheme to arbitrary finite dimensional LTI systems with disturbances. In doing so, we develop a disturbance observer theory for solving the disturbance rejection problem. We also present a discrete version of the theory with discussion of sampling and time-delay effects.

• The Korean Journal of Community Living Science
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• v.28 no.2
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• pp.257-271
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• 2017

The purpose of this study was to suggest basic data for prevention of child abuse by examining the patterns and characteristics of child abuse observed at child-care centers. Data was collected by pre-service early childhood teachers majoring in child studies in an education practice session from May 1 to May 31, 2015 based on examined information and class discussion. This study shows that emotional abuse was performed most often, followed by neglect and physical abuse. Physical abuse was observed as a form of punishment and beating, whereas emotional abuse was observed in the form of force, sarcastic remarks, verbal attacks, and disregard. Neglect was observed as exclusion and indifference. Most crucial prevention against child abuse lies in teachers' personality education and concerns with their own mental health as well as children's rights education.

• Journal of the Korean Home Economics Association
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• v.36 no.7
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• pp.69-82
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• 1998

The purpose of the study was to examine the adaptability of AAI(Adult Attachment Interview) in Korea. The subjects were 20 mothers who had toddlers from middle class. AAI was administrated to them. Interviews were audiotaped and transcribed verbatim. The results showed that Korean Mothers' AAI classifications were Secure-Autonomous(F) 60%, Insecure=Dismissing(Ds) 20%, Insecure-Preoccupied(E) 5%, Insecure-Unresolved/disorganized(U/d) 15%. The classification of AAI was significantly related with mothers' education, but not mothers' age. Autonomous mothers discribed consistently in evaluation of attachment-related experiences and valued attachment. Dismissing mothers showed a incoherent discourse and dismissed attachment-related experiences and relations. Preoccupied mother sticted to past attachment relationship and perplexed with evaluation of these experiences. Unresolved mothers showed lapse during discussion of loss or abuse and were not free from past experiences. Based on the findings of the study, it was found th AAI(Adult Attachment Interview) can be used for evaluation of mother's internal working model in Korean culture.

• Journal of the Korean Professional Engineers Association
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• v.44 no.5
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• pp.31-35
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• 2011

The WHO/International Agency for Research on Cancer(IARC) has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans(Group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use on 31, May 2011. It takes 10 years after announcing the electric magnetic as possibly carcinogenic to humans(Group 2B) and 14 years after starting research project. It is too late as mentioned, too weak in terms of the same class to 'pickles & coffee' and too little in terms of using words 'more studies required'. The guidelines on human exposure to electromagnetic fields have been developed to provide guidance to identify the safety of exposure to electromagnetic fields. On the recent recommendations of safety guidelines, there has been discussion on possible chronic effects of electromagnetic fields with much lower or no threshold. This paper riviews the global trends of safety guidelines and has suggested the new guidelines for protecting the human health, wildlife and insects.

• The Journal of Korean Society for School & Community Health Education
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• v.6
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• pp.65-73
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• 2005

Purpose : This study was to describe health behavior, self-esteem, health knowledge, health education needs, and to assess the effects of health behavior on self-esteem, health knowledge and health education needs. Study Methods : A self-administrated questionnaire was carried out to randomly selected students in two middle schools in Seoul, Korea. The questionnaire contains items of health behavior on self-esteem, health knowledge and health education needs. Results : The mean score differences of health behavior were not meaningful. Health behavior had significantly positive correlation with self-esteem, health knowledge and health education needs. The multiple regression showed that higher self-esteem, health knowledge and health education needs was associated with higher scores of health behavior. Discussion : Health knowledge has a significant effect on health behavior Therefore, regular health education class must be based on health knowledge and health education needs.

• The Journal of the Korea Contents Association
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• v.6 no.3
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• pp.93-101
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• 2006

The purpose of this study is to design internet CEDA(Cross Examination Debate Association) debating model for the internet-based learning. Comparing to open discussion model that is widely spreaded in regular classes, the CEDA model can enhance learner's thinking skills, logicality, analytic skills, and judgement ability. In the first study, 196 students were provided the specific CEDA model guideline and participated debate activities through the internet. The results of the students' debate were analyzed based on the evaluation criteria. The results showed that the students' evaluation scores were high overall. They favored the CEDA model over the open discussion model, and showed positive attitudes and perceptions on the CEDA internet debate activity. In the second study, another 200 students were participated in two different tutor supporting CEDA debating groups, one is advanced tutor strategy group and the other is general tutor strategy group. The results showed that the advanced tutor supporting group had significantly high scores on the cross examination and providing evidence on debating. This study finally suggests the CEDA internet model for general use. In conclusion, this study also suggests the next steps to elaborate the CEDA internet model not only for the university settings, but also for general school settings. The user manuals should be developed to assist instructors, students, and tutors to guide better debate activities through the internet CEDA class. Also further research should be conducted to provide various debate models and applications for the variety of learning environments, and so the schools to use the CEDA model more widely in the internet classes.

• Journal of the Korean Society for Library and Information Science
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• v.35 no.3
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• pp.173-189
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• 2001

This paper presents a framework for observable behavior that can be used as a basis for user modeling, and it reports the results of a pair of user studies that examine the joint utility of two specific behaviors. User models can be constructed by hand, or they can be teamed automatically based on feedback provided by the user about the relevance of documents that they have examined. By observing user behavior, it is possible to obtain implicit feedback without requiring explicit relevance judgments. Four broad categories of potentially observable behavior are identified : examine, retain, reference, and annotate, and examples of specific behaviors within a category are further subdivided based on the natural scope of information objects being manipulated . segment object, or class. Previous studies using Internet discussion groups (USENET news) have shown reading time to be a useful source of implicit feedback for predicting a user's preferences. The experiments reported in this paper extend that work to academic and professional journal articles and abstracts, and explore the relationship between printing behavior and reading time. Two user studies were conducted in which undergraduate students examined articles or abstracts from the telecommunications or pharmaceutical literature. The results showed that reading time can be used to predict the user's assessment of relevance, that the mean reading time for journal articles and technical abstracts is longer than has been reported for USENET news documents, and that printing events provide additional useful evidence about relevance beyond that which can be inferred from reading time. The paper concludes with a brief discussion of the implications of the reported results.

• Journal of the Korean Society of Earth Science Education
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• v.3 no.1
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• pp.65-75
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• 2010

The purpose of this study is to present a Freedom Inquiry Method by Revised Science Curriculum in 2007. This study introduced IIM(Independent Inquiry Method), PBL(Problem Based Learning), Small Inquiry Method, Science Notebooks, Project Learning Method about Freedom Inquiry Method. The results of this study are as follows: First, IIM(Independent Inquiry Method) is studying method in the inquiry process center. The inquiry process is composed of total 9 phases, inquiry subject really it is, detailed aim deciding, information searching, it searches, quest result it arranges, aim evaluation, the report making, it announces, it evaluates, it is become accomplished. Second, It is a studying method which it starts with the problem which is Problem Based Learning, study atmosphere creation phase, problematic presentation phase and sleep static problem solving the phase which it attempts, it is become accomplished with autonomous studying phase, coordinated studying and discussion studying phase, discussion resultant announcement studying phase, arrangement and evaluation. Third, Small Inquiry Method, Call it accomplishes the call grade of the students among ourselves 4~8 people degree where only the quest learning capability is similar within class. Also interaction and coordinated function of the members between it leads and the subject which is given in the group it cooperates and it solves with it is a quest method which arrives to aim of commonness. This method divides on a large scale in three parts, it becomes accomplished in programming phase, quest accomplishment and resultant announcement. Fourth, Science Notebooks learns a scientific contents and a scientific quest function and the possibility of decreasing in order to be, from the fact that the help which it understands. This planing, data searching, it searches, becomes accomplished with resultant arrangement, announcement and evaluation. Fifth, The Project Learning Method the studying person oneself studying contents, it establishes a plan and it collects it accomplishes process of etc. it evaluates it leads and a subject and information and with real life it is a method which it studies naturally from the learning environment inside which is similar. This is preliminary phase, project start, project activity and project arrangement.

• Journal of the Korean School Mathematics Society
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• v.17 no.3
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• pp.385-408
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• 2014

The purpose of this study is to find out the actual status of the math after-school program in the elementary school and the content of the program. We survey the 115 math external math lecturers of the 100 elementary schools in Busan and analyze the results. Research questions are set as follows. 1. What is the status of the elementary math after-school? 2. How is the content of the program of the elementary math after-school? The results of the survey are analyzed as follows. First, any of the external math after-school lecturer did not major in math education and 87% of them majored in another discipline. Second, 47% of the external math after-school lecturers are employed by privately-held companies. Third, 64.4% of the content of the after-school programs is the supplement and deepening of the regular math class. Fourth, 76.5% of the time of the first class of the math after-school program is 50 minutes and 46% of the math after-school opens 5 classes per a week. Fifth, most programs consist of the problem-solving style class. Sixth, it is difficult to run the math after-school according to students' level and grade. Based on the above discussion, I suggest the following. First, math after-school class should be the action-oriented class to motivate the positive and interested participation of the students. Second, lecturer training and various math class programs is required to improve the quality of the math after-school class.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.642-657
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• 2022

This study aimed to investigate how elementary school students' science reading ability is influenced by collaborative problem-solving for competency instruction strategy using science reading text. This study recruited two groups of elementary students in fifth grade. The experimental group underwent an instruction strategy using science reading text, while the comparative group experienced a science class using a textbook. Afterward, data from the science reading ability tests, voice recordings of the discussion process involving each group, and class videos were collected and analyzed. The results showed that science classes that used collaborative problem-solving for their competency instruction strategy via science reading text were effective in enhancing elementary school students' science reading ability. Meanwhile, the science reading ability test results indicated that the experimental group had statistically higher total scores than the comparative group in the three subelements, especially "introspection and evaluation" and "integration and interpretation" owing to their significant improvement in high-level cognitive processes. In these classes, the students read the materials that the teacher provided, participated in the discussion based on what they have read, and had the chance to reflect on their reading processes. Overall, students' science reading ability was enhanced through this process.