• Structural Engineering and Mechanics
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• 제63권1호
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• pp.55-64
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• 2017

The paper concerns concrete carbonation, the phenomena that occurs in every type of climate, especially in urban-industrial areas. In European Standards, including Eurocode (EC) for concrete structures the demanded durability of construction located in the conditions of the carbonation threat is mainly assured by the selection of suitable thickness of reinforcement cover. According to EC0 and EC2, the thickness of the cover in the particular class of exposure depends on the structural class/category and concrete compressive strength class which is determined by cement content and water-cement ratio (thus the quantitative composition) but it is not differentiated for various cements, nor additives (i.e., qualitative composition), nor technological types of concrete. As a consequence the selected thickness of concrete cover is in fact a far estimation - sometimes too exaggerated (too safe or too risky). The paper presents the elaborated "self-terminated carbonation model" that includes abovementioned factors and enables to indicate the maximal possible depth of carbonation. This is possible because presented model is a hyperbolic function of carbonation depth in time (the other models published in the literature use the parabolic function that theoretically assume the infinite increase of carbonation depth value). The paper discusses the presented model in comparison to other models published in the literature, moreover it contains the algorithm of concrete cover design with use of the model as well as an example of calculation of the cover thickness.

• 한국멀티미디어학회논문지
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• 제20권12호
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• pp.1992-1999
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• 2017

This study proposes a decorative typeface which is produced through the concept of trigonometric functions in an open-source programming language known as Processing. First, the theoretical background of Processing and trigonometric functions as well as previous research in this area are analyzed. Second, basic modules of 'V', 'I', 'O', and 'M' were created for use as the final alphabet typeface with the concept of a trigonometric function. Third, a decorative parabolic curve that encircles the base module was created. Finally, the modules created on Processing were edited in Adobe Illustrator to create a typeface set with characters from A to Z. Various artworks using Programming can produce an infinite number of different versions by modifying only some of the variables and codes, and this method can include multimedia features such as text, images, videos, interactive art and various forms of content and media. Therefore, with regard to expression, the possibilities are endless. In this study, I attempt to expand the field of visual culture using programming and computational methodologies. In contrast to the digital typeface production method, which relies on existing graphic tools, this study is meaningful because it expands the range of use of decorative typefaces.

• 한국의상디자인학회지
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• 제5권2호
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• pp.1-15
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• 2003

Buttons in general reflect the culture of the society, and their values depend on practicality, decorative feature, and symbolism. Their infinite potential enables us to attempt various original changes in formative factors such as forms, patterns, colors, materials and sizes. In addition new styles, methods, and techniques are tried to show that the decorative feature becomes stronger today than it did in the past when the function was more important. Now buttons are not only a factor of clothing but have value as composite art works reflecting the pride, idea and culture of a nation. Moreover consumers' interest in new designs increases everyday as the moderns' desire for unique individuality rises. Button designs of Korea, however, are still far behind in the aspects of materials, qualities, and methods, facilities, and scale of production. And uniform mass production prevails without the buttons of creative and artistic values made due to the lack of specialized designers. Therefore it seems necessary to carry out historial studies simultaneously with the rising interest in button designs now. Prior to developing new designs, the study will examine those of western buttons that are the origin, going through relevant literature and data to define the characteristics of each era and type. It may provide basic data for developing the backward button designs of Korea.

• 한국지반신소재학회논문집
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• 제8권4호
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• pp.47-51
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• 2009

우리나라의 자연재해는 대부분 풍수해에 의해 발생하며, 강우시 산비탈이 갑작스럽게 붕괴되는 산사태로 인해 큰 재난을 겪고 있다. 사면파괴를 유발하는 요인은 다양하고 요인들이 서로 관련이 있기 때문에 어느 하나의 요인에 의하여 사면파괴의 발생을 설명할 수는 없으나, 외적요인 중 강우는 가장 중요한 외적요인이다. 따라서, 본 논문에서는 무보강된 일반사면과 친환경 호안구조물로 사면보호공법이 적용된 사면을 대상으로 실내 강우재현실험을 수행하였으며, 강우강도와 사면경사에 따른 유출량과 저류량을 분석하여 호안구조물의 침식에 대한 사면보호효과에 대하여 검토하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.892-896
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• 2001

백색잡음 불규칙 과정으로 모델링된 난류형태의 유체운동에 의하여 가진되는 비선형 시스템의 특성과 제어기법에 대해 연구하였다. 고려된 물리적인 모델은 주질량과 끝단 집중질량을 갖는 보형태의 구조물이다. 그 지배방정식은 확률론적 관점에서 F-P-K 접근법으로 유도되었고, 비선형 해석법으로 Gaussian Closure방법을 이용하였다. 비선형 시스템의 제어기법으로는 슬라이딩 모드 제어기를 최초로 확률영역에서 설계하고 그 효과를 확률영역 및 시간영역에서 고찰하였다.

• 전자공학회논문지SC
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• 제46권4호
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• pp.49-57
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• 2009

이 논문에서는 특별한 형태의 일반화된 연속시간 Lyapunov 방정식과 해의 존재성에 대해 다룬다. 이것은 무한대의 고유치를 가지는 descriptor 시스템에 대해 시스템의 안정성을 분석하기 위해 필요하다. 주요결과로써 먼저 지수 1과 2를 가지는 경우의 descriptor시스템에 대해 안정성을 위한 필요충분조건을 먼저 제안하고 다음으로 일반적인 경우의 descriptor 시스템에 대하여 특별한 형태의 Lyapunov 방정식을 이용하여 비슷한 안정성 조건을 제안한다. 마지막으로 제안한 방법의 타당성을 보이기 위한 예제를 살펴본다.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.543-550
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• 2016

The Active Superconducting Current Controller (ASCC) is a new type of Superconducting Fault Current Limiters (SFCL) which can limit the fault current in different modes. It also has the particular abilities of compensating active and reactive powers for electrical networks. In this paper, it is confirmed that the performance of ASCC in different operating modes introduces a limiting impedance in series with the network which can even degrade the transient stability and the operation of the Over-Current Relays (OCR) employed in a power system. In addition, the model of a three-phase ASCC is simulated, and the effect of descriptive modes on the current limiting level is investigated. For the transient stability analysis, a single machine-infinite bus system is tested, and the effect of operation modes is studied based on an equal area criterion obtaining the critical time and the critical angle. Modifying the setting parameters of OCR such as time dial and pick-up current, the protective coordination is also studied in different operating modes.

• 복식
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• 제62권6호
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• pp.139-153
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• 2012

To prolong the rapid progress of IT, it is necessary to develop contents through IT convergence among the existing goods & service and process areas to create new added-values. In particular, the wedding dress industry has infinite potential in utilizing various contents like virtual fitting by connecting with newly compelling IT areas such as smart phones, Augmented Reality (AR), and application contents. In the meantime, a large scale of the wedding industry has gained global competitiveness due to consulting expertise and the influence of the Korean Wave, whereas most small-sized wedding dress shops in Korea fall short of developing wedding dress designs and receiving relevant information. Accordingly, the purpose of this study was to help brides who have difficulties in choosing a wedding dress by decreasing their time and effort by providing wedding dress designs and information, according their desired image, body type, and circumstances through the utilization of virtual fitting application contents. Not only that, this study aims to diversify and specialize in wedding information and to help users to set a guideline for wedding dresses that are most suitable for them. Moreover, this study has an academic meaning in proposing an interdisciplinary convergence research model through the study of wedding dress design development, AR, and application contents utilization.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1062-1067
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• 2015

Floating architecture is a type of building that is geographically located on a sea or a river. It floats under the influence of buoyancy, and does not have an engine for moving it. Korea is a peninsula surrounded by sea except on the north side, so floating architectures have been mainly focused on two points: solving the issue of small territory and providing various leisure & cultural spaces. Floating architectures are expected to save energy effectively, if they use sea water heat, which is known to be clean energy with infinite reserves. To use sea water heat as the heat source and/or heat sink, this study proposes a model in which a sea water heat exchanger is embedded in the concrete structure in the lower part of the floating architecture that is submerged under the sea. Based on the results of performance evaluations of the sea water heat exchanger using CFD (computational fluid dynamics) analysis and mock-up experiments under various conditions, it is found out that the temperature difference between the inlet and outlet of the heat exchanger is in the range of $3.06{\sim}9.57^{\circ}C$, and that the quantity of heat transfer measured is in the range of 3,812~7,180 W. The CFD evaluation results shows a difference of 5% with respect to the results of mock-up experiment.

• 한국전자파학회논문지
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• 제23권4호
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• pp.415-423
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• 2012

본 논문에서는 유전 알고리즘을 이용한 광대역 부배열 최적화 설계에 대해 기술하였다. 먼저 무한 주기 구조의 삼각 배열을 이용하여 광대역 복사 소자를 설계하였다. 너치 구조의 복사 소자로 정면 빔 조향 시 능동 반사 계수 -10 dB 이하를 만족하는 최대 및 최소 주파수 비가 약 2:1 정도로 광대역 특성을 가지고 있다. 이러한 광대역 배열 소자 1,100여개로 이루어진 안테나 구조의 부배열 최적화를 위해 유전 알고리즘을 이용하였다. 대조군인 규칙 부배열 안테나 구조와 비교해서 최적화(불규칙) 부배열 안테나 구조의 최대 부엽 준위가 4.5-5.5dB 정도 개선되었음을 확인하였다.