• 전기학회논문지P
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• 제53권4호
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• pp.195-200
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• 2004

Many kinds of speed sensorless control system of induction motor had been developed. But it is difficult to implement at the real system because of complex algorithm and equations. This paper investigates a novel speed sensorless control of induction motor using neural networks. The proposed control strategy is based on neural networks using stator current and output of neural model based on state observer. The errors between the stator current and the output of neural model are back-propagated to adjust the rotor speed, so that adaptive state variable will coincide with the desired state variable. This algorithm may overcome several shortages of conventional model, such as integrator problems, small EMF at low speed and relatively large sensitivity of stator resistance variation. Also, this paper presents a newly developed optimal equation about the momentum constant and the learning rate. The proposed algorithms are verified through simulation.

• 한국학교수학회논문집
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• 제3권2호
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• pp.59-67
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• 2000

Two groups of students, who are the students in the natural science course of high school in Korea, learned the equation of figure in space (point, line, plane) to understand more effectively with two different textbooks. One group was taught with the textbook used now in most high schools and the other group was taught with the textbooks systematized by associating old concept with new concept. The results are as follows : 1) We need understand the basic concept of vector plainly and flexibly to apply it to the solution of problems. 2) It helps students understand new concepts how we should establish the concept about point, line and plane in space by applying the concept about those on XY plane, 3) It is very effective in understanding the new knowledge system more easily to analyze the existent concepts and to arrange them systematically for efficient understanding of new concepts. 4) The texts which consist of contents organized by basic concepts improve students' learning ability.

• 품질경영학회지
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• 제41권1호
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• pp.53-68
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• 2013

Purpose: The paper presents research that examine relationship difference education quality, satisfaction, loyalty in university education sector. Specifically, the effects of difference education quality on student satisfaction and loyalty in the context of education quality are examined. Methods: A model of difference education quality effect on student satisfaction and loyalty is introduced and tested in the university using student perceptions of provider. Questionnaire was developed, and data was collected and analyzed for this study with SEM(Structural Equation Modeling). Results: The results are as follows: Education capability, BNIE(Business Newspaper In Education) are significantly influenced on student satisfaction. In addition, student satisfaction is significantly influence on external customer satisfaction, professor image. Professor image is significantly influence on student loyalty. Conclusion: Upon learning of student need and want, professor can focus on development of difference education quality based on student need and want.

• 대한음성학회지:말소리
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• 제63호
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• pp.1-21
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• 2007

Locus equation scatterplots for [bilabial stop + vowel] syllables were obtained from 16 non-native speakers of English and Russian. The results indicated that both Russian speakers of English and English speakers of Russian exhibited modifications towards respective L2 norms in slopes and y-intercepts. All non-native locus equations generated exhibited linearity. Accordingly, the basic results reported in [17] were reverified by securing a larger subject base. More experienced speakers displayed better approximations to L2 norms than less experienced speakers, indicating the necessity of perception- and articulation-related learning for allophonic variations due to adjacent phonetic environments.

• 한국수학교육학회지시리즈A:수학교육
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• 제45권4호
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• pp.439-457
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• 2006

This research was to understand the features of mathematization and didactical phenomenology, in a way that was not a routine calculation of equation, rather a complete comprehension by the reinventing historical principles of the equation. To achieve the purpose of this study, one-mate middle school student participated in the study. Interview and observation were used for collecting data during the student's performance. The results of research were: First, the student understood the mathematical concepts from a real life and developed the abstract concepts from it, which were very intimately related with his life. Second, the skill and formula definition were accomplished with the accompanying predicted and consequently derived mathematical concepts. Third, through the approach of using the history of mathematics, he became more interested in what he was doing and took lessons with confidence. Forth, the student performed his learning based on the historical reinventing principle under the proper guidance of a teacher.

• Wind and Structures
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• 제25권1호
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• pp.25-38
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• 2017

This study investigates the dynamic analysis of a transversely isotropic thin plate. The plate is made of hyperelastic John's material and its constitutive law is obtained by taken the Frechect derivative of the highlighted energy function with respect to the geometry of deformation. The three-dimensional equation governing the motion of the plate is expressed in terms of first Piola-Kirchhoff's stress tensor. In the reduction to an equivalent two-dimensional plate equation, the obtained model generalizes the classical plate equation of motion. It is obtained that the plate under consideration exhibits harmonic force within its planes whereas this force varnishes in the classical plate model. The presence of harmonic forces within the planes of the considered plate increases the natural and resonance frequencies of the plate in free and forced vibrations respectively. Further, the parameter characterizing the transversely isotropic structure of the plate is observed to increase the plate flexural rigidity which in turn increases both the natural and resonance frequencies. Finally, this study reinforces the view that non-classical models of problems in elasticity provide ample opportunity to reveal important phenomena which classical models often fail to apprehend.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제29권4호
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• pp.699-722
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• 2015

본 연구의 목적은 라그랑주의 방정식론을 바탕으로 한 방정식의 해법을 고등학교 1학년 수업에 적용하여 방정식의 해법과 관련한 근과 계수의 관계와 대칭성의 의의를 인식하게 하는 것이다. 대칭성은 라그랑주의 방정식론의 핵심 아이디어이며, 근과 계수의 관계는 그의 해법에 있어 중요한 수단이다. 학생들은 수업을 통해 근과 계수의 관계에 대한 학습 의의를 인식하였고, 대칭성의 아이디어를 이해하였으며, 새로운 해법에 흥미를 나타내었다. 이러한 연구는 학교수학에서 다루는 국소적인 방정식의 해법만이 아닌 교수학적 조직화에 의한 체계적인 방정식론에 대한 경험을 주며, 방정식의 해법과 관련한 지식들의 연결성을 이해하게 한다.

• 한국산학기술학회논문지
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• 제17권9호
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• pp.340-350
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• 2016

이 연구는 평생학습에 참여하는 성인학습자의 특성, 참여동기, 강사의 학습진행방법, 기관만족, 학습성과의 구조적 인과관계를 분석하는 것을 목적으로 수행하였다. 또한 성인학습자 특성과 학습성과의 관계에서 다른 세 개의 변인이 어떻게 매개역할을 하는지 역시 살펴보았다. 연구대상은 평생교육에 참여하는 성인학습자 444명에게 설문을 실시하고 구조방정식모형 분석을 통해 연구가설을 검증하였으며 연구 결과는 다음과 같다. 첫째, 성인학습자의 특성이 학습성과 뿐만 아니라 강사의 학습진행방법, 참여동기, 기관만족에 미치는 영향은 모두 정(+)적인 유의한 결과를 얻었다. 둘째, 강사의 학습진행방법은 기관만족에는 유의한 영향을 미치는 것으로 나타났지만, 참여동기에는 영향을 주지 않으며 학습성과에는 부(-)적인 영향을 미치는 것으로 나타났다. 또한, 참여동기는 학습성과와 기관만족에 모두 유의한 영향을 미치는 것으로 나타났다. 셋째, 성인 학습자 특성과 학습성과 사이에서 최적의 매개경로 모형을 살펴본 결과, 기관만족을 통한 경로가 최적임을 확인하였다. 이러한 결과를 바탕으로 평생교육현장에서 성인학습자의 학습성과를 높이기 위한 방안과 평생교육기관의 역할을 제언하였다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2019년도 추계학술대회
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• pp.110-113
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• 2019

본 논문에서는 임베디드 시스템에서의 양자화 기계학습을 수행할 경우 발생하는 양자화 오차를 효과적으로 보상하기 위한 방법론을 제안한다. 경사 도함수(Gradient)를 사용하는 기계학습이나 비선형 신호처리 알고리즘에서 양자화 오차는 경사 도함수의 조기 소산(Early Vanishing Gradient)을 야기하여 전체적인 알고리즘의 성능 하락을 가져온다. 이를 보상하기 위하여 경사 도함수의 최대 성분에 대하여 직교하는 방향의 보상 탐색 벡터를 유도하여 양자화 오차로 인한 성능 하락을 보상하도록 한다. 또한, 기존의 고정 학습률 대신, 내부 순환(Inner Loop) 없는 비선형 최적화 알고리즘에 기반한 적응형 학습률 결정 알고리즘을 제안한다. 실험결과 제안한 방식의 알고리즘을 비선형 최적화 문제에 적용할 시 양자화 오차로 인한 성능 하락을 최소화시킬 수 있음을 확인하였다.

• 제어로봇시스템학회논문지
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• 제8권7호
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• pp.584-588
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• 2002

The real-time characteristic of the adaptive leaning control algorithms is validated based on the applied results of the hydraulic servo system that has very strong a non-linearity. The evolutionary strategy automatically adjusts the search regions with natural competition among many individuals. The error that is generated from the dynamic system is applied to the mutation equation. Competitive individuals are reduced with automatic adjustments of the search region in accordance with the error. In this paper, the individual parents and offspring can be reduced in order to apply evolutionary algorithms in real-time. The feasibility of the newly proposed algorithm was demonstrated through the real-time test.