• 대한수학회보
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• 제52권4호
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• pp.1059-1068
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• 2015

The paper is devoted to studying a fourth-order degenerate parabolic equation, which arises in fluid, phase transformation and biology. Based on the existence and uniqueness of one semi-discrete problem, two types of approximate solutions are introduced. By establishing some necessary uniform estimates for those approximate solutions, the existence and uniqueness of the corresponding parabolic problem are obtained. Moreover, the long time asymptotic behavior is established by the entropy functional method.

• 한국농촌건축학회논문집
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• 제6권2호
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• pp.65-78
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• 2004

Transformation of housing space is the most accurate physical trail to understand main needs from residents. The scope of the study targeted the 7 si & gun districts in Gyeongsangnam-do, this study is designed to consider the characteristics of space transformation in rural apartment houses and provide basic materials for the development of rural apartment houses. The results of the study are as follow. First, such spaces as corridor and stairway are transformed into storages and outside the houses are installed tap water facility, bicycle storage. and toilet. Second, in autumn seasons when crops and grains are harvested, parking lot and rooftop are used as the space drying such agricultural products. Third, space transformation within the houses has been different depending on family type and main businesses in terms of function and time to seek efficiency and stability of residence. Fourth, rural residents concentrate on a simple change of space usage and replacement of ageing or dilapidated equipment and facilities rather than space transformation incurring more financial burden.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.334-336
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• 2009

An elastic-plasticity model during the austenitic decomposition was derived and implemented to incorporate the two important deformation behaviors observed during the phase transformations: the volumetric strain and transformation induced plasticity due to the temperature change and phase transformation. To obtain transformed phase volume fractions during cooling, the fourth order Runge-Kutta method was used to solve the Kirkaldy's phase kinetics model which is function of temperature, austenitic grain size and chemical composition. The volumetric strain was calculated by considering the densities of constituent phases, while the transformation induced plasticity was based on the micro-plasticity due to the volume mismatch between soft austenitic phase and other harder phases. The constitutive equations were implemented into the implicit finite element software and a simple boundary value problem was chosen as a model problem to validate the effect of transformation plasticity on the deformation behavior of steel under cooling from high temperature. It was preliminary concluded that the transformation plasticity plays a critical role in relaxing the developed stress during forming and thus reducing the magnitude of springback.

• 한국농촌건축학회논문집
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• 제12권2호
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• pp.67-76
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• 2010

This study examined and analyzed uses, transformations, changes of plane and arrangement, and changes of space structure of housing components with traditional folk houses located at Kyideok village, Hanrim-eup, Jeju, and the results of the study can be summarized as follows. First, the exposure of arrangement of folk houses at Kyideok village, Jeju was evenly distributed to the east, the southeast, the northeast and the west in order and it was little different from the use of sunshine conditions by placing the main room on the south in traditional houses of land areas. Second, the space structure of inner room before transformation was divided into seven types. 3-room type was classified into "Sangbang-centered three-room type" and "nanggan-centered three-room type", 4-room type into "four-room type with inner access to warehouse", "four-room type with outer access to warehouse", "kitchen-divided four-room type", "four-room type with two kitchens", "four- room type with nanggan at the right back". Third, according to types of change in arrangement type, the first is new annex addition to existing inner room, the second is the removal of existing annexes including outer room, the third is the extension of inner room size without new construction of annex, the fourth is new construction of annex with new plane form after removal of existing annex, the fifth is no change in arrangement of inner room, outer room, stable, warehouse, etc. Fourth, transformation of space components led to changes of space structure as well as those of plane form. Changes of space structure were divided into reduction type of circulation to specific factors, negligence type without using increased space factor, and addition type having various circulations through the increase of convenience space.

• 무역상무연구
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• 제37권
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• pp.361-389
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• 2008

The purpose of this study is to detect the factors which have an effect on transformation level and performance and to provide the ways of successful transformation and vitalization from OEM to ODM. This study was proceeded by an empirical analysis. A model and hypotheses were set up and they were verified through the empirical analysis. Those factors were divided into four, inner company factors, strategic factors, core competence factors and purchase determining factors. In the result of the model suitability analysis on the study model of relationship among 'influencing factors of ODM transformation - ODM transformation level-export performance', every factors, $X^2=912.067$, DF=261, p value=0.000, GFI=0.737, AGFI=0.620, NFI=0.786, IFI=0.837, CFI=0.834, Q value=3.495 were rather insufficient to be a good model, but they were good enough for the general analysis. Taking these accounts into consideration, this study suggests the following implications. First, making a plan and setting up strategies in advance are required. Second, financial plan has to be prepared. Third, trends in global markets have to be analyzed. Fourth, companies have to focus on developing new materials and products through R&D. Fifth, quality competitiveness and quality control systems are required.

• Wind and Structures
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• 제23권5호
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• pp.421-447
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• 2016

Wind-induced and earthquake-induced excitations on tall structures can be effectively controlled by Tuned Liquid Damper (TLD). This work presents a numerical simulation procedure to study the performance of tuned liquid tank- structure system through ${\sigma}$-transformation based fluid-structure coupled solver. For this, a 'C' based computational code is developed. Structural equations are coupled with fluid equations in order to achieve the transfer of sloshing forces to structure for damping. Structural equations are solved by fourth order Runge-Kutta method while fluid equations are solved using finite difference based sigma transformed algorithm. Code is validated with previously published results. The minimum displacement of structure is observed when the resonance condition of the coupled system is satisfied through proper tuning of TLD. Since real-time excitations are random in nature, the performance study of TLD under random excitation is also carried out in which the Bretschneider spectrum is used to generate the random input wave.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2451-2454
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• 2003

In this paper, we propose the computation reduction methods of LSP(Line spectrum pairs) transformation that is mainly used in CELP vocoders. In order to decrease the computational time in real root method the characteristic of four proposed algorithms is as the following. First, scheme to reduce the LSP transformation time uses met scale. Developed the second scheme is the control of searching order by the distribution characteristic of LSP parameters. Third, scheme to reduce the LSP transformation time uses voice characteristics. Developed the fourth scheme is the control of searching interval and order by the distribution characteristic of LSP parameters. As a result of searching time, computational amount, transformed LSP parameters, SNR, MOS test, waveform of synthesized speech, speech, spectrogram analysis, searching time reduced about 37.5％, 46.21％, 46.3％, 51.29％ in average, computational amount is reduced about 44.76％, 49.44％, 47.03％, 57.40％. But the transformed LSP parameters of the proposed methods were the same as those of real root method.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2010년도 춘계학술발표논문집 1부
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• pp.257-260
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• 2010

In this paper, we propose the computation reduction methods of LSP(Line spectrum pairs) transformation that is mainly used in CELP vocoders. In order to decrease the computational time in real root method the characteristic of four proposed algorithms is as the following. First, scheme to reduce the LSP transformation time uses mel scale. Developed the second scheme is the control of searching order by the distribution characteristic of LSP parameters. Third, scheme to reduce the LSP transformation time uses voice characteristics. Developed the fourth scheme is the control of searching interval and order by the distribution characteristic of LSP parameters. As a result of searching time, computational amount, transformed LSP parameters, SNR, MOS test, waveform of synthesized speech, spectrogram analysis, searching time is reduced about 37.5%, 46.21%, 46.3%, 51.29% in average, computational amount is reduced about 44.76%, 49.44%, 47.03%, 57.40%. But the transformed LSP parameters of the proposed methods were the same as those of real root method.

• 한국BIM학회 논문집
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• 제8권4호
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• pp.23-33
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• 2018

Recently, the industry actively adopts the cutting-edge technologies of the fourth industrial revolution and uses them to enhance the productivity and service of mass-customization. The manufacturing industry is creating new processes and business models by achieving digital transformations through a lean start-up approach aimed at achieving the highest customer satisfaction with minimal resources. Although attempts are made to manufacture the building by introducing the latest technology in architecture, it is applied sporadically, not as an integrated system, in the entire phase of the architectural project. This paper analyzes the changes in the construction industry through the application of core technologies of the fourth industrial revolution. Design processes are analyzed for the digital transformation of the construction industry by case study of advanced architectural design practice. A novel design concept model 'Architectural lean startup' is proposed by combining the architectural process and the lean start up method. Through the design of the bus stop based on the architectural lean startup concept, it is confirmed that the designer repeats the 'Generate-Test-Analysis' to develop the design and generate the final result.

• 한국초등수학교육학회지
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• 제16권3호
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• pp.359-388
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• 2012

본 연구는 공간 감각의 하위 요인 틀을 추출하고, 이를 기초로 초등학교 4, 5, 6학년 학생들의 공간 감각 실태를 조사하고자 하였다. 이를 위해 이론적 고찰을 바탕으로 공간 감각을 정신적 회전, 정신적 변환, 도형 배경 지각으로 이루어진 공간 시각화 능력과 방향 감각, 거리 감각, 위치 감각으로 이루어진 공간 방향 능력으로 구분하고, 공간 감각 검사 도구를 개발하여, 수도권에 소재한 5개 초등학교 4, 5, 6학년 423명을 대상으로 학생들의 실태를 조사하고, 하위 요인별 및 문항별 정답률 및 정답과 오답에 대한 반응 분포를 제시하고, 대응 표본-t 검정, ANOVA 분석과 다중 비교 분석을 통해 학년 간 및 학년별 차이를 분석하였다. 분석 결과는 첫째, 학년에 따른 공간 감각은 향상되나 공간 시각화 능력의 상승폭이 공간 방향 능력보다 훨씬 크고 그 순위가 역전되고, 둘째, 공간 감각 하위 요인 중 특히 부족한 부분은 정신적 변환과 위치 감각이며, 셋째, 요인별 및 문항별 학년 간 유의미한 차이는 대부분 학습 경험에 기인하지만, 자연적 인지 발달 능력 및 문항의 복합성에도 영향을 받는 것으로 나타났다. 이를 기초로 공간 감각 교수 학습에의 시사점을 제안하였다.