• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.3 s.333
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• pp.9-16
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• 2005

The mobility in strained Si inversion layer on $Si_{1-x}Ge_x$ is calculated considering a quantum effect(subband energy and wavefunction) in inversion layer and relaxation time approximation. The quantum effect in inversion layer is obtained by using self-consistent calculation of $Schr\ddot{o}dinger$ and Poisson equations. For the relaxation time, intravalley and intervalley scatterings are considered. The result shows that the reason for the enhancement in mobility as Ge mole fraction increases is that the electron mobility in 2-폴드 valleys is about 3 times higher than that of 4-폴드 valleys and most electrons are located in 2-폴드 valleys as Ge mole fraction increases. Meanwhile, for the phonon-limited mobility the fitting to experimental data, Coulomb and surface roughness mobilities are included in total mobility, Deformation potentials are selected for the calculated effective field, temperature, and Ge mole fraction dependent mobilities to be fitted to experimental data, and then upgraded data can be obtained by considering nonparabolicity in Si band structure.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.4
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• pp.15-23
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• 2002

In most cryogenic liquid rocket engines, liquid oxygen manifold and injector are not thermally insulated from room temperature environment fur reducing system complexity and the weight. This feature of cryogenic liquid rocket engine results in the situation that cryogenic liquid oxygen flow is easy to be vaporized especially in the vicinity of the manifold and the injector wall. The research in this paper is focused on two-phase flow phenomena of liquid oxygen in rocket engine. Vapor fraction was estimated by comparing the measured two-phase flow pressure drop in engine manifold and the injector with ideal single phase pressure drop. Heat flux into cryogenic flow is estimated by measuring the wall temperature on the engine manifold to examine boiling characteristics. Suitable correlations for cryogenic two-phase flow were also reviewed to see their applicability. In addition, the effect of vapor generation in liquid rocket engine manifold and injector on engine performance and stability was considered.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.135-138
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• 2008

최근 인간을 모방하는 휴머노이드 로봇(Humanoid robot)에 대한 관심이 증가함에 따라, 기계공학, 생체공학, 제어이론 등 여러 분야에서 관련 연구가 활발히 진행되고 있다. 이에 본 논문에서는 액츄에이터(Actuator)가 없이 경사진 지면을 걸을 수 있는 두 발을 가진 패시브 로봇(Passive robot)을 대상으로 강화학습과 메니폴드(Manifold control) 기법을 사용하여 안정적으로 걸을 수 있도록 제어기(Controller)를 설계하는 방안을 고려한다.

• Journal of Veterinary Clinics
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• v.27 no.6
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• pp.726-728
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• 2010

Autosomal-dominant polycystic kidney disease (AD-PKD) is common in Persian and Persian-related breeds, and is sporadically reported in Scottish Fold cats. A 5-year-old male Scottish Fold cat was diagnosed with polycystic kidney disease based on screening tests and abdominal ultrasonography and died 3.5 months after diagnosis. The cat had 14 kittens with three queens, including his female sibling, with an age range of 3 months to 8 years. Genetic testing to confirm the genetic transmission of AD-PKD which detects the mutated PKD1 gene was performed. Abdominal ultrasonography confirmed the presence of renal cysts. Nineteen cats were screened in the present study (13 males and 6 females), with an age range of 3 months to 8 years. The results of renal ultrasonography agreed with the genetic test results in the 19 cats in which both tests were performed and 8 cats were diagnosed as ADPKD based on these tests. AD-PKD has not been investigated in cats in South Korea. Moreover, this is the first report of AD-PKD in a family unit of Scottish Fold cats.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2002.03a
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• pp.20-25
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• 2002

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.92-93
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• 2005

• Korean Institute of Interior Design Journal
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• v.26 no.6
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• pp.42-52
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• 2017

In this modern world of drastic change, folding architecture was an alternative that offered a novel architectural insight. Today, the folding technique is being used above and beyond architecture, spreading to fashion, lighting, medicine, etc. Especially in the interior space design field, the folding technique is in the limelight as an alternative to create an original space for modern society. However, research and experiments into folding mainly remains at philosophical interpretation or architectural examples, and even these were mostly before the 2000s. Therefore, the present study determined it necessary to look deeply into the post-2000s folding technique focusing on interior space. In this paper, 33 cases of indoor space where folding technique appears are derived, and classified them again by use. The folding technique which was the first step of Sophia Vyzoviti's experiment on her book, "Folding Architecture" was extracted and used as the framework. We summarizes the range of application of folding techniques (interior space in general, floor, wall, ceiling, etc.) and major folding techniques by combining photographs, drawings, and descriptions of the works of the architects. This paper summarizes the characteristics of the space described comprehensively, and draws out the spatial characteristics of the modern interior space where the folding technique appears.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.11a
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• pp.9-9
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• 2000

우주추진기관의 모든 부품은 생산 시 규정된 절차를 거쳐서 작동의 이상유무를 확인하는 시험을 거친다. 우주추진기관은 특별한 경우를 제외하고는 실 비행 상태에서 시험하기가 어렵거나 불편하기 때문에 지상에서 시험을 수행하여 성능 및 안정성 등을 확인하게 된다. 지상연소시험을 수행하기 위해서는 비행용 엔진을 대상으로 엔진 메니폴드에 비행 시와 같은 조건의 추진제가 공급될 수 있게 해줘야 한다. 기존에 시험장이 이미 구축되어 있는 경우 엔진의 운용조건에 맞추어 엔진에 맞게 엔진과 시험설비 연결부분이 수정되게 된다.(중략)

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.10
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• pp.102-111
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• 2004

The procedure of design and manufacture of sub-scale combustor using bipropellant swirl injector with external mixing for a liquid rocket engine are described. The results of cold flow test, ignition test and combustion test of the sub-scale combustor are also given in this paper. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has a injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl injector and 18 main swirl injectors. The cold flow, ignition and combustion tests were successfully performed without damage of combustor. Results of hot firing tests show that combustion efficiency meets the target of design and operations of start and stop cyclogram are stable and high frequency combustion instability does not occur.

• Journal of the Korean Society of Costume
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• v.66 no.5
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• pp.122-132
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• 2016

In today's society, being considered ecological in fashion design and having a cultural and humanistic approach is important. Using a technological approach, the fold concept was applied to understand and analyze the ecological characteristics of a modern fashion aesthetic design. The concept of 'Ecological Aesthetic Design', which we discuss in this study, is part of human nature, and the design concept is used to consider the relationship between the man and the environment to the design of Victor Papanek. From the perspective of interrelation between the components of an ecosystem, the possibility of the fold's application to ecological aesthetic design can be summarized by wholeness, biodiversity, evolution, homeostasis, and circularity. The concept of the fold is revealed mainly through three types of characteristics: indeterminate complexity, potential continuity, and decentralized interaction relationship. Based on the characteristics of the concept presented earlier, this study conducted a case review by distinguishing contemporary fashion that applied the complex, various, and indeterminate fold concepts into flexible transformation, continuity, and complementary circularity. This study was interpreted from the ecological aesthetic point of view based on the nature of the contingent folds presented before applying modern fashion concepts. It focused on the morphological side, and excluded the material aspects of the case study in order to examine the complex, diverse and content aspects. The result of the study is as follows. The study of the research areas that help the understanding of the changing fashion phenomenonneeds to be encouraged, and there should be a new research category, which can contribute to the ecological aesthetic design concept conversion.