• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1015-1019
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• 2001

This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft switching commutation. In the first place, the steady state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current-fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

• Journal of architectural history
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• v.29 no.5
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• pp.51-61
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• 2020

Historically, rhythm has played a key role not only in musical composition, but also in architectural design. In 1893, architectural theorist and art scholar August Schmarsow, in "The Essence of Architectural Creation," created a new definition of architecture as space-creation and characterized rhythm as a design principle. However, this new idea was confronted by Heinrich Wölfflin. While Schmarsow's theory represents a dynamic world-view based on anthropomorphism, the architectural theory of Wölfflin is based on the notion of harmony, displaying a kind of conservative stasis. These two main streams have greatly influenced the development of modern architecture. The concept of space has prevailed in the discourse of modern architecture, but the principle of rhythm has seldom received any positive recognition. This article introduces and develops the concept of rhythm and disputes whether Behrens and Frankl in particular, two who dispute Schmarsow's theories, have used the concept of rhythm in terms of space. I conclude that they could not overcome the notion of the physical-the body-, thus their use of the term rhythm is incongruous with the notion of space. The idea of rhythm in architectural creation remains an up and coming idea.

• Journal of The Korean Association of Information Education
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• v.14 no.4
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• pp.505-516
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• 2010

Recently, the Ministry of education science and technology announced a revised information and communication technology curriculum, emphasizing aspects of computer science education rather than application of computer softwares. This change would benefit students to stimulate their thinking ability and facilitate creativity learning through in-depth understanding of principles of computer science, compared to the previous curriculum of computer education mainly focused on the skills of utilizing application softwares. Thus, the paper presents the design of a computer education curriculum based on the principles of computer science education, which would lead to trigger constructive ideas for improvements on the subject so that students may experience better education in the area.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.55-59
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• 2002

This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft switching commutation. In the first place, the steady state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current -fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.2
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• pp.49-55
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• 2003

This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft switching commutation. In the first place, the steady state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment of set-up in laboratory system of this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current-fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

• Journal of the Korean Mathematical Society
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• v.51 no.1
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• pp.99-111
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• 2014

In this paper, we deal with the problem of practical observer design and the practical stabilization for a class of perturbed impulsive systems. We show that, under the classical conditions of uniform complete controllability and uniform complete observability of the nominal system without impulsive effects, it is possible to design an observer controller for a class of perturbed linear impulsive system when the origin is not an equilibrium point.

• Proceedings of the Korea Society of Design Studies Conference
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• 2000.11a
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• pp.58-59
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• 2000

인간은 과학기술을 이용하여 괘적하고 안락한 생활을 추구하게 되었고, 주거건축에서도 이러한 경향은 인텔리전트 주거, 또는 스마트 주거라는 지능형 주거가 등장하게 되었다. 그리고, 현재 영국, 프랑스, 미국, 일본 등 세계 여러 나라에서 지능형 주거에 관한 연구가 진행되고 있으며, 국내에서도 공동주거에 첨단 지능형 설비를 적용하고 있다.(중략)

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.223-228
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• 2000

The principle objective of this study is to make an integrated development environment with an expert system for designing RC retaining walls. The program has several advantages over conventional design tools and characteristics of functions. It is easy to use and to obtain the technical reports with minor efforts. Various possible design alternatives can be compared, then the most optimal design can be selected in terms of construction cost and structural safety.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11B
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• pp.961-967
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• 2008

Congestion control is one of major mechanisms to avoid dropped packets. Many researchers use optimization theories to find an efficient way to reduce congestion in networks, but they do not consider robustness that may lead to unstable network utilities. This paper proposes a new methodology in order to solve a congestion control problem for wired networks by using a robust design principle. In our particular numerical example, the proposed method provides robust solutions that guarantee high and stable network utilities.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.217-229
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• 1990

The Applegate-Kennedy classification, the drawing of removable partial denture design using color coding, the selective tissue placement impression method in case of Class I and Class II removable partial dentures, the design of the swing lock attachment of an alternative approach to conventional removable partial denture, the design of the intracoronal or extracoronal attachment, and the removable partial denture design using a rotational path were presented. The following conclusions from the above things were presented : 1. The swing lock attachment removable partial denture can be effective to an alternative approach when the design of conventional removable partial denture is improper with markedly mobile remaining teeth or missing key abutments. 2. Intracoronal or extracoronal attachments must be selected care-fully considering the conditions of the abutment teeth and alveolar ridge whether more occlusal loads to the abutment teeth or to the alveolar ridge are distributed. 3. It must be almost prerequisite that a functional impression is taken in case of Class I and class II removable partial dentures and in case of tooth-borne removable partial dentures, a removable partial denture using rotational path is strong, hygienic, esthetic, and can be accomplished successfully in the clinical aspect when it is properly designed and fabricated through the complete understanding of an indication and a principle. 4. All necessary informations must be achieved with carefully investigated surveying procedure according to each clinical case by Applegate-Kennedy classification which can be helpful and useful in the clinical application and it is important that dentists themselves must be in the habit of drawing a reasonable partial denture design using a color coding in the paper sheet.