• International Journal of CAD/CAM
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• 제5권1호
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• pp.59-68
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• 2005

Euclidean Voronoi diagram of spheres in 3-dimensional space has not been explored as much as it deserves even though it has significant potential impacts on diverse applications in both science and engineering. In addition, studies on the data structure for its topology have not been reported yet. Presented in this, paper is the topological representation for Euclidean Voronoi diagram of spheres which is a typical non-manifold model. The proposed representation is a variation of radial edge data structure capable of dealing with the topological characteristics of Euclidean Voronoi diagram of spheres distinguished from those of a general non-manifold model and Euclidean Voronoi diagram of points. Various topological queries for the spatial reasoning on the representation are also presented as a sequence of adjacency relationships among topological entities. The time and storage complexities of the proposed representation are analyzed.

• 한국과학교육학회지
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• 제14권2호
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• pp.111-122
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• 1994

This study tried to find the effect to the representation patterns of science concepts upon the momentum effect. The previous studies showed that the momentum effect is influenced by students' cognitive levels and the abstractness of test items. The representation patterns of science concepts are divided into 4 different types: quantitative and qualitative, verbal and image. The research method used in this study is time series design. The period is 50 days. The period is divided into "pre-lest", "intervention-test", "post-test". Pre-test period is 5 days and in this period class instruction does not exist. Intervention-lest period is 30 days and in this period class instruction exist. Post-test period is 15 days and in this period class instruction does not exist. The results showed longer momentum effect on the image-qualitative representation pattern than the other representation patterns. Qualitative concepts is formed better than quantitative. Momentum effects is not artifact but the essential characteristics of science study.

• 제어로봇시스템학회논문지
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• 제14권8호
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• pp.727-732
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• 2008

In this paper, the state-space representation of generalized complimentary filter is proposed. Complementary filter has the suitable structure to merge information from sensors whose frequency regions are complementary. First, the basic concept and structure of complementary filter is introduced. And then the structure of the generalized filter and its state-space representation are proposed. The state-space representation of complementary filter is able to design the complementary filter by applying modern filtering techniques like Kalman filter and $H_{\infty}$ filter. To show the usability of the proposed state-space representation, the design of Inertial Navigation System(INS) vertical channel damping loop using Global Positioning System(GPS) is described. The proposed GPS/INS damping loop lends the structure of Baro/INS(Barometer/INS) vertical channel damping loop that is an application of complementary filter. GPS altitude error has the non-stationary statistics although GPS offers navigation information which is insensitive to time and place. Therefore, $H_{\infty}$ filtering technique is selected for adding robustness to the loop. First, the state-space representation of GPS/INS damping loop is acquired. And next the weighted $H_{\infty}$ norm proposed in order to suitably consider characteristics of sensor errors is used for getting filter gains. Simulation results show that the proposed filter provides better performance than the conventional vertical channel loop design schemes even when error statistics are unknown.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제22권4호
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• pp.223-237
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• 2019

수학적 과정에서 나타나는 언어 구문론적 표현 체계와 정의적 표현 체계 사이에는 긴밀한 상호 작용이 이루어진다. 한편, 수학적 개념 체계도 본질적으로 은유적이므로 언어적 표현을 통해 나타나는 수학적 개념 구조에 대한 분석은 수학 학습에 작용하는 인지 정의적 장애 요인의 근원을 밝히는데 도움이 될 수 있다. 이에 본 연구에서는 수학 영재아의 문제해결 프로토콜을 인지언어와 메타정의의 관점에서 분석하여 텍스트 및 은유의 기능적 특성과 메타정의의 기능적 특성 사이의 관계성을 파악하였다. 그 결과 문제해결의 성공 여부에 따라 수학 영재아의 인지적, 정의적 특성이 반영된 행위의 양상이 서로 다르게 나타났다. 성공적이지 못한 문제해결의 경우에는 성공적인 경우에 비해 내부 표현 체계로서의 은유를 활용하는 행위가 상대적으로 빈번하게 나타났다. 또한 은유의 인지언어학적 측면이 문제해결에 중요하게 작용하면서 동시에 은유라는 외적 표현에는 메타정의적 속성이 긴밀하게 관련되어 나타났다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.680-683
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• 1999

A thyristor controlled shunt compensator, which is installed in the middle of the transmission line is adopted for controlling real power flow in a simple power transmission system. By means on the Fourier series representation of the thyristor switching action and the system parameters, the thyristor current equations are derived, which transmit the required real power of the simple power transmission system and inform the thyristor firing angle, the thyristor conduction angle, the power flows and the harmonic characteristics EMTP simulations at the various operating points show the dynamic characteristics of the thyristor controlled shunt compensator and correspond to the results calculated with the Fourier series representation.

• 한국과학교육학회지
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• 제21권5호
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• pp.841-854
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• 2001

The purpose of this study was to find the effect of these variables on the duration of the momentum effect. To examine the momentum effect for gravitational field concepts, an intensive time series design was used. We collected data every day except Sundays and holidays for 50 days; 5 days for baseline, 30 days for intervention, and 15 days for the follow up We adopted cognitive levels and styles as students characteristics and two item characteristics(quantity versus quality, and word versus picture) as the item representation patterns. In this study, the momentum effect was influenced by students characteristics and item representation patterns. The results showed that two variables, cognitive style and quantity/quality, were the most influential factors for the duration of momentum effect. Field independent students showed a longer duration than field dependent students did. In addition, students showed a longer duration in quality items than in quantity items. However, students cognitive levels(formal or preformal) and word/picture presentations seemed to have relatively weak effect on the duration of the momentum effect.

• 전력전자학회논문지
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• 제4권4호
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• pp.368-376
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• 1999

본 논문은, 대표적인 FACTS기기중의 하나인 싸이리스터제어 병렬보상기의 특성 연구를 수행한다. 이를 위하여 푸리에 공간에서 전력조류 조건을 만족하는 싸이리스터 점호각을 수치해석적으로 구하고, 그 계산 결과를 이용하여 정상상태 및 고조파 특성을 해석하였다. 그리고, Poincare Mapping 이론을 이용한 스위칭 주파수영역에서 안정도 해석과 EMTP 시뮬레이션을 이용한 시평면상에서 해석결과의 검증 및 여러 운전점에서 과도응답특성의 비교연구를 수행하였다.

• 한국의류산업학회지
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• 제16권5호
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• pp.689-697
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• 2014

This study aims to analyze the representation forms of bloggers' personal style on the fashion blogs and enlighten their values which can be actively applied to design and marketing in fashion industry. Image representation of fashion bloggers is reflected by the characteristics in the digital environment, which are the creative manipulation of expression and the production of virtual and fantastic images by taking advantage of the composite medium such as images, music, videos, articles, etc. Also real time updates in blog indicate the latest trends in terms of the representation of image as the actual currency. The study conducted case studies of 5 women's personal fashion blogs through the verification of a variety of global fashion media and blog ranking sites: Style Bubble, Style Rookie, The Cherry Blossom Girl, The Blond Salad, and Fashion Toast. Research findings are as follows. First, the application of creative design elements is indicated as symbolic items, self-made designs, DIY, and various mix and match emphasizing design elements such as color, patterns, proportion, etc. Second, the virtual representation is very highlighted on the story telling applied by film like production or digital effect. Third, the commercial application with mainly sponsored wardrobe and designer collaboration indicates promoting a updated trend as well as a specific brand or designer to make their business profits.

• 대한화학회지
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• 제56권1호
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• pp.128-136
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• 2012

이 연구에서는 중등학교 과학 교사 20명을 대상으로 밀도에 대한 내용 표상을 조사하여 각 교사의 밀도 수업과 관련된 내용교수지식 수준을 판단하고, 그에 따라 내용 표상의 구성 요소별로 어떤 특징이 있는지를 분석하였다. 연구결과, 과학 교사들의 내용교수지식 수준은 전반적으로 보통 수준으로 판명되었다. 교사들의 내용교수지식 수준에 따라 나타나는 내용 표상의 구성 요소별 특징은 '학습자의 선개념에 대한 이해'를 제외한 7개의 구성 요소에서 차이가 크게 나타남을 알 수 있었으며, 이 연구에서는 그 차이를 구성 요소별로 분석하고, 그 특징을 추출하였다. 또한, 내용교수지식 수준이 중간인 교사들에게서 나타난 내용 표상의 구성 요소별 특징은 내용교수지식 수준이 높은 교사들 보다는 낮은 교사들과 대부분의 구성 요소에서 비슷한 것으로 밝혀졌다.

• 한국생활과학회지
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• 제24권3호
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• pp.451-461
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• 2015

It was the purpose of this study that propose architectural design process through analysis of concepts considering regional characteristics. The procedure of this study was as follows : First, classifying design process through investigating paper-survey and case studies. And We would investigate representation process of design concepts applied to design competitions entries. Finally, we would investigate design process applied to buildings in various districts. In the results, we could find that domestic architects were applying to site plan, floor plan, elevation plan, section plan and mass plan-led design process to express design concepts. And according to survey on buildings in various districts, we could verify that architects were applying various design process to express design concepts according to site characteristics. These results could help architects to design appropriately, according to site characteristics.