인버터 구동시의 유도전동기의 정상상태특성

정영준,좌종근 濟州大學校 情報通信硏究所 2000 情報通信硏究所論文集 Vol.3 No.-

In this paper. the Γ type eqivalent circuit is used to analyze the steady state characteristics of induction motor driven by inverter source. The base tests for equivalent circuit parameters of induction motor are a no-load test by rated frequency (60Hz) and a blocked rotor test by 25% of rated frequency (15Hz) which are perfomed with inverter source. and measurement of the de resistance of the stator winding. To determine more accurate parameters, four simultaneous equations obtained from equivalent circuit of the no-load test and blocked rotor test are solved by using initial values which are evaluated from simplifed equivalent circuits. The induction motor performances are computed by using these parameters and compared with measured values of the tested motor. Then it is found that the compared results show good agreement between them.

誘導機 等價回路定數의 精密算定

趙瑢哲,左宗根 濟州大學校 工科大學 産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.1

This paper presents a new method to determine the T-type equivalent circuit parameters for steady state analysis of induction motors. To determine the parameters, four simultaneous equations are obtained from the T-type equivalent circuit conditions. The initial values for these equations are evaluated by the simplified equivalent circuits, and then the parameters are calculated by iterative computation. Test results are compared with the computed results of the conventional method and the proposed method to demonstrate the validity of the proposed method. And it is found that the latter method is more accurate than the former method.

不平等 線間電壓 條件下에서의 系統連繫 誘導發電機의 解析

趙瑢哲,左宗根 濟州大學校 情報通信硏究所 1998 情報通信硏究所論文集 Vol.1 No.-

This paper presents an analysis of steady state characteristics of induction generator that has no neutral connection, under unbalanced nonsinusoidal grid line voltage. For this analysis, T-type equivalent circuit is used and a new algorithm for determining circuit parameters is introduced. Symmetrical component and double revolving field theory are applied for unbalanced voltage analysis. and harmonic analysis is used for nonsinusoidal analysis. The validity of analysis theory is confirmed from the compared results between computed and test values.

회전자에 정류회로를 가지는 유도전동기의 교류회로 모델에 의한 해석

조용철,좌종근,문경주 濟州大學校工科大學産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.2

In this paper, the characteristics of induction motor which has rotor rectifier circuit are analyzed using a new six elements ac model. The effects of resistance on dc circuit which are caused by current over lap angle and voltage drop of rectifier are considered in the proposed model for this analysis. The proposed model and Sen's five elements ac model which is not considered these effects are used to analyse. and the analyzed results are compared with the experimental results in order to verify the Proposed model. It is found that the results of the proposed method are good agreement with the experimental results.

회전자에 정류회로를 가지는 유도전동기의 교류회로 모델에 의한 해석

문경주,조용철,좌종근 濟州大學校 産業技術硏究所 1998 산업기술연구소논문집 Vol.9 No.2

In this paper. the characteristics of induction motor which has rotor rectifier circuit are analyzed using a new six elements ac model. The effects of resistance on dc circuit which are caused by current over lap angle and voltage drop of rectifier are considered in the proposed model for this analysis. The proposed model and Sen's five elements ac model which is not considered these effects are used to analyze. and the analyzed results are compared with the experimental results in order to verify the proposed model. It is found that the results of the proposed method are good agreement with the experimental results.

科學的 態度 및 興味를 爲한 學習方法 및 學習資料 開發에 關한 硏究

吳允謙,金英昊,左升元 濟州敎育大學 科學敎育硏究所 1977 科學敎育硏究誌 Vol.2 No.-

The purpose of this study is to lead learners to observe the natural objects and phenomena correctly, and set up practical examples of effective methods for the study of elementary science by the learners participating at positive activities in the study with absorbing interest. I have analysed the problems existing in the study of elementary science which is being progressed in the proper educational institutes upon my investigation of the study from the following points of view : 1. Learning method in elementary science which pupils are desirous of. 2. Constitution of school course requested in the study of elementary science 3. Interest of the pupi1s in their study of elementary science. 4. Response shown by the parents of the pupils ill their own study of elementary science. As the result of my analysis mentioned above, the followinig problems have been detected : 1. The further pupils advance in their study of the subject, the more they are interested in independent study of method, and the more they are desirous of individual experiment needed in its study. 2. Questions, instructions, and demonstrations given on the part of teachers have great influences on durability of the pupils' interest and concern in consequence of their teaching methods. 3. The result of my analysis shows 5,2% of the pupils are fond of the subject, and 22,3% of them are not; (N=578) the followings are the reasons shown in otation as described : a. Contents of the subject are hard to make out. b. Vast bulk of contents of the subject is unbearable. c. Scientific terms used in the subject are inintelligible. d. The subject is uninteresting. The reasons of their being fond of the subject are : a. They have chances of conducting experiments and observation on the subject. b. They can enjoy pleasure experiments on the subject. 4. The subject meets with little response on the part of the parents on the occasion of their own study of the subject, proving of little service to them. The reasons ascertained are : a. They lack understanding of the contents of the subject. (54.2%) b. They can hardly afford to prepare for research materials (36.2%) This shows the fact that we can hardly warrant any sanguine expectations regarding their home learning of the subject, The following are methods of teaching conducted practically in order to solve the abovementioned problems, the result of which got the Pupils interested intensively in their study of the subject, bring on a remarkable change in their learning attitude : 1. Teaching method by funny form style ( applied by the lesson, "Light and Shawdgw", 2nd Pear grae) 2. Teaching method by vigorous mannerr of acfivity in teaching (applied by the lesson, ('Eleectric Current and Magnetic Field, 6th year grade) a. Investigation of the pupils, readiness. b. Presentation of phenomena for independent study of the subject. 3. Teaching method by analysis of teaching materials.

발달장애학생을 위한 웹기반 의사소통능력신장 프로그램의 개발과 적용 사례

김동현,유영환,김좌중,천경철,이청용,김봉수 국립특수교육원 2005 연구보고서 Vol.- No.10

발달장애학생의 의사소통능력은 단순한 언어문제 이상의 의미를 지닌다. 의사소통능력은 모든 학습의 기초가 되고 결국 인간의 삶의 질을 좌우하게 하는 중요한 요소가 되고 있기 때문에 의사소통능력에 문제가 많은 발달장애학생에게 있어서 의사소통능력 신장은 매우 중요하다. 발달장애학생의 언어 및 의사소통능력의 결함은 사회적 결함과 인지적 결함에 상호 관련성이 있어 다른 사람으로부터의 의사소통을 이해하는 능력과 자신의 생각을 표현하는 능력이 제한되어 다른 사람과의 상호관계를 맺는데 어려움이 많았다. 따라서 발달장애학생의 언어지도는 생활 장면에서 교수하는 것이 가장 바람직하다고 하겠다. 그러나 지금까지 주로 활용된 전통적인 언어지도 방법은 어휘를 증가시키고, 발화의 길이를 널리는 데는 효과가 있었지만, 학습된 내용을 생활 장면에서의 일반화에는 문제점이 있는 것으로 지적되고 있다. 발달장애학생의 언어지도 방법은 일상생활 속에서 학습 내용을 선정하고 이를 실생활 장면 혹은 이와 유사한 환경에서 효과적으로 지도할 수 있는 적절한 교수 방법이 필요하다. 그래서 발달장애학생의 의사소통능력 신장을 위한 환경중심 언어지도 방법을 활용한 웹(Web)기반 언어지도 프로그램을 개발하였다. 웹(Web)기반 언어지도 프로그램은 제7차 특수학교 기본교육과정과 국립특수교육원에서 발간한 ‘발달장애학생의 언어교육 프로그램(1998)’ 분석을 통하여 개인 · 가정생활, 학교 · 사회생활, 경제 · 여가생활 등의 6개 영역으로 구분하여 각 영역별 학습주제를 선정하였으며, 학습주제에 대한 학습의 진행 형태는 학습목표, 낱말학습, 상황학습, 평가로 진행할 수 있도록 하였으나, 학습자의 현재 수행 능력을 고려하여 능력에 따른 진행의 절차를 학습자가 선택할 수 있게 하였다. 본 프로그램을 적용해본 결과 다음과 같은 교육적인 효과를 얻을 수 있었다. 첫째, 웹을 활용한 가상체험을 통하여 적극적이고 흥미 있는 참여를 유도하며, 학습자 중심의 주도적인 학습과 안내자, 촉진자로서의 교사의 역할을 통해 발달장애학생의 의사소통 능력을 신장시킬 수 있었다. 둘째, 교실에서 이루어지는 지금까지의 수업방식을 탈피하여 학습자가 언제, 어디서나, 누구든지 학습할 수 있는 열린 학습체제의 교육환경을 조성할 수 있었다. 셋째, 문자정보, 그래픽, 애니메이션, 사진, 음성, 비디오 등 다양한 형태의 정보가 상호대화 형식으로 활용되며, 수준별 반복학습을 실시함으로써 교수-학습 방법의 개선뿐만 아니라 양질의 수업을 진행하는데 도움을 줄 수 있었다. 본 프로그램을 활용한 언어지도가 발달장애학생의 의사소통능력 신장을 위한 최선의 방법이라고 말할 수는 없으며, 언어지도의 한 가지 방법이라고 말할 수 있다. 따라서 본 프로그램의 활용한 언어지도는 학교에서 교사가 학생의 능력과 흥미를 고려하여 지도한다면 발달장애 학생의 의사소통능력 신장에 많은 도움이 될 것이다. The developmental disability of the metal handicapped children means more than simple linguistic problem. The developmental disability is the base of all the learning and important factor which decides the happiness of the human being finally, so the extension of mutual understanding ability is so important, in the case of the metal handicapped children who have a problem of the mutual understanding ability. In the case of the metal handicapped children, the defects of the mutual understanding and linguistic ability are related with the social defect and the defect of recognition, and the ability of understanding about mutual relations with other people and self-expression ability are limited. So they have many problems in mutual relations with other people. Therefore, the linguistic instruction of the metal handicapped children is recommended to be done in the living. But, the traditional linguistic instruction which's used mainly as yet, is effective in increase of a vocabulary and the length of a locutionary act, but it has a problem in the popularization of the learning in the real life. The method of the linguistic instruction for the metal handicapped children, should be selected as contents in the real life, and the right learning method which can be done under the real life or the similar environment with it, is needed. Because of the above realities, the linguistic teaching web-based program is developed, using the linguistic instruction which is focused on the environment, for the extension of the mutual understanding ability of the metal handicapped children. In the linguistic teaching web-based program, it is divided with 6 field (personal · home life, school · social life, economical · leisure life) and the educational subject classified by each field is selected, by the analysis of 'The linguistic educational program for the children who have developmental disability' published by the 7th basic education course of special school and the national special education organization. Besides, the progress form of learning about the educational subject is directed by educational goal, word learning, situation learning and valuation, but a learner can choose a procedure followed by ability, regarding to his accomplishment ability. As the result of the application of this program, the educational effects that we could get are the following : 1. We could lead a positive and interesting participation by virtual experience through WEB, and the communication ability of the metal handicapped children was extended by a role of a teacher, as a guide and promoter and a leading learning focused on a learner. 2. The teaching method which is done in school now, is dismissed and we could form the educational environment of the learning system that a learner could learn, without distinction of time, a place and a person. 3. The various form of information, like text, graphic, animation, photo, sound, video and so on, is applied as a form of communication. Therefore, the program was useful in not only the improvement of the teaching-learning method, but also the proceeding of the effective lesson. The linguistic teaching which use this program, can not be the best method of the extension of the mutual understanding ability and it's just one method of linguistic teaching. if the linguistic teaching which use this program is conducted, regarding to a ability and a interest of a student, it will be so useful in the extension of the mutual understanding ability, for the children who have developmental disability.

2차측에 정류회로를 이용한 유도전동기의 불평형 전압 운전해석

문경주,조용철,좌종근 濟州大學校 情報通信硏究所 1999 情報通信硏究所論文集 Vol.2 No.-

The Characteristics of unbalanced voltage operation for induction motor which has rectifier circuit in the secondary side are analyzed using a six elements ac circuit model referred to the primary side. The symmetrical component method is used to analyze motor performance and the positive and negative sequence circuit model are composed by taking account of the current overlap angle and the voltage drop of rectifier circuit. The characteristics of induction motor under unbalanced symmetrical voltage are computed and compared with the measured values to verify the proposed method

예비유아교사의 유아창의인성교육에 대한 교육요구도 분석

좌승화(Jwa, Seung Hwa),천희영(Chun, Hui Young),이미란(Lee, Mi Ran) 학습자중심교과교육학회 2019 학습자중심교과교육연구 Vol.19 No.18

본 연구는 예비유아교사가 인식하는 유아창의인성교육에 대한 중요도와 실행도의 수준을 알고, 교육요구도를 분석하는데 목적을 두었다. 전문대학 유아교육과 3학년학생 193명이 유아창의인성교육에 대한 교사의 교수방법, 교사의 가치관과 태도, 유 아의 학습방법, 창의인성교육의 운영방향의 4개 하위차원에 대한 중요도와 실행도를 평정한 자료를 기술통계분석, t검증하고, Borich의 요구도 분석과 The Locus of Focus 모델에 의한 우선순위 도출방법을 적용하여 교육요구도를 분석하였다. 본 연구의 결과, 예비유아교사는 유아창의인성교육에 대한 중요도와 실행도를 높은 수준으로 인식하고 있고, 중요도에 비해 실행도의 인식 수준이 낮은 것으로 나타났다. 하위차원별로 교육요구도 분석 결과, 교사의 교수방법 차원에서는 유아의 발달수준과흥미 고려, 다양한 체험학습 제공 등이, 교사의 가치관과 태도 하위차원에서는 가정·지역사회·국가 간 원활한 연계 도모, 교사의 유아기 창의인성교육의 중요성에 대한 인식이 우선순위가 높게 나타났다. 유아의 학습방법 하위차원에서는 유아가 다양한 활동을 통한 배려·나눔·협력 경험하기, 유아가 자신의 생각이 타인의 생각과 다를 수 있음을 인정하며 문제를 해결하도록 돕기 등이, 창의인성교육의 운영방향 하위차원에서는 부모의 긍정적 양육태도로 창의인성교육 활성화, 인간과 자연에 대한 이해와 존중에 기초한 창의적 사고 기르기 등이 높은 우선순위를 보였다. 이상의 결과로써 교사양성과정 교육과정의 개선을 위한 정보를 제공했다는데 연구의 의의가 있다. The purpose of this study was to identify the perceived importance and performance level and to investigate the educational needs of pre-service early childhood teachers in creativity and personality education of young children. The subjects were 193 pre-service early childhood teachers at three-year junior colleges. They answered the survey regarding creativity and personality education of young children. Data were analyzed using descriptive statistical analysis, t-test, Borich’s Needs Analysis, and the Locus for Focus Model. The results of this study were as follows. The perceived importance and performance levels in creativity and personality education were high and the degree of performance was lower than that of importance. Results of analysis on educational needs showed that educational needs in teaching methods were prioritized in children’s developmental level, considering children’s interests, and providing various hands-on experience. Connection among family, community, and country and teachers’ recognition on creativity and personality education were prioritized in teachers’ value system and attitude. Educational needs in learning method of young children were prioritized in experiencing caring and sharing through various activities and recognizing different opinions and perspectives with others, and helping young children solve problems. Educational needs in administration were prioritized in activating creativity and personality education through positive parenting and cultivating creative thinking based on understanding and respecting human beings and nature. The results of this study suggest some directions for improvement of the curriculum of the early childhood teacher training program.

Inorganic- and Total-N Contents and Expression of N Assimilation Genes in Tomato Leaves under Various N Conditions

Jwa-Kyung Sung(성좌경),Ye-Jin Lee(이예진),Rog-Young Kim(김록영),Ju-Young Lee(이주영),Jong-Sik Lee(이종식),Byoung-Choon Jang(장병춘),Tae-Wan Kim(김태완),Beom-Heon Song(송범헌) 한국토양비료학회 2010 한국토양비료학회 학술발표회 초록집 Vol.2010 No.10