• Title/Summary/Keyword: Dynamic US

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Design and Implementation of Solid-State Kicker Modulator for PLS-II (PLS-II 용 반도체 스위치 기반 키커 펄스 모듈레이터 설계 및 제작)

  • An, Suk-Ho;Kong, Hyung-Sup;Park, Wung-Hoa;Lee, Byung-Joon
    • Proceedings of the KIPE Conference
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    • 2019.07a
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    • pp.307-308
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    • 2019
  • The Pohang Light Source (PLS) - II is a 3 GeV third-generation synchrotron radiation facility. To inject electron beam from LINAC, a kicker modulator system and kicker magnets are installed in the PLS-II storage ring tunnel. The injected beam then falls into the storage ring beam dynamic aperture. This paper describes the design and implementation of the solid-state kicker modulator for PLS-II. The solid-state kicker modulator is consisted of high voltage solid state switch stacks. the technical considerations of the solid-state switch stacking for kicker modulator is discussed. The achieved capability of the solid-state kicker modulator demonstrates that is fulfills the design requirement of providing half-sine pulsed current of 10kA (peak), 6us (Base-width), with jitter < 2ns (Standard deviation). simulation and experimental results are presented to demonstrate the performance of the solid-state kicker modulator.

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Solitary Necrotic Nodules of the Liver Mimicking Hepatic Metastasis: Report of Two Cases

  • Kwon-Ha Yoon;Ki Jung Yun;Jung-Min Lee;Chang Guhn Kim
    • Korean Journal of Radiology
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    • v.1 no.3
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    • pp.165-168
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    • 2000
  • We present two cases of solitary necrotic nodules of the liver which on radiologic images mimicked hepatic metastasis. Solitary necrotic nodule of the liver is a rare but benign entity which histopathologically consists of an outer fibrotic capsule with inflammatory cells and a central core of amorphous necrotic material. The lesion was seen on contrast-enhanced CT as an ovoid-shaped hypoattenuating nodule; on CT during hepatic arteriography as enhancing nodule; on intraoperative US as a target-appearing hypoechoic nodule; on T2WI as a hyperintensity nodule, and on dynamic MR as a subtle peripheral enhancing nodule. Although the radiologic features are not specific, solitary necrotic nodule of the liver should be included in the differential diagnosis of hepatic metastasis.

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An Empirical Test of the Dynamic Optimality Condition for Exhaustible Resources -An Input Distance Function- (투입물거리함수를 통한 고갈자원의 동태적 최적이용 여부 검증)

  • Lee, Myunghun
    • Environmental and Resource Economics Review
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    • v.15 no.4
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    • pp.673-692
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    • 2006
  • In order to test for the dynamic optimality condition for the use of nonrenewable resource, it is necessary to estimate the shadow value of the resource in situ. In the previous literatures, a time series for in situ price has been derived either as the difference between marginal revenue and marginal cost or by differentiating with respect to the quantity of ore extracted the restricted cost function in which the quantity of ore is quasi-fixed. However, not only inconsistent estimates are likely to be generated due to the nonmalleability of capital, but the estimate of marginal revenue will be affected by market power. Since firms will likely fail to minimize the cost of the reproducible inputs subject to market prices under realistic circumstances where imperfect factor markets, strikes, or government regulations are present, the shadow in situ values obtained by estimating the restricted cost function can be biased. This paper provides a valid methodology for checking the dynamic optimality condition for a nonrenewable resource by using the input distance function. Our methodology has some advantages over previous ones: only data on quantities of inputs and outputs are required; nor is the maintained hypothesis of cost minimization required; adoption of linear programming enables us to circumvent autocorrelated errors problem caused by use of time series or panel data. The dynamic optimality condition for domestic coal mining does not hold for constant discount rates ranging from 2 to 20 percent over the period 1970~1993. The dynamic optimality condition also does not hold for variable rates ranging from fourth to four times the real interest rate.

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The Effect of Types of Abutment and Dynamic Loading on Microgap between Implant Fixture and Abutment (임플란트 지대주 종류와 동적하중이 고정체와 지대주의 미세간극에 미치는 영향)

  • Oh, Byung-Doo;Choi, Yu-Sung;Shin, Soo-Yeon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.26 no.4
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    • pp.389-403
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    • 2010
  • Titanium and gold-alloy abutments have been used for a long-time in the clinical situations, but the use of zirconia abutments also increased. This study was designed to compare and evaluate the microgap differences according to types of abutment and dynamic loading. Titanium abutment, zirconia abutment and gold-alloy abutment (UCLA plastic) were connected into titanium implants of external hexagonal structure US II ${\phi}$ $3.75{\times}11.5$ mm (Osstem Co., Seoul, Korea) with the tightening torque of 30 Ncm. A sine type dynamic loading of 25-250 N and $30^{\circ}$ inclination from long axis was applied for $10^5$ times. Using the SEM both before and after the loadings, implant-abutment interfaces were analyzed on the labial, palatal, mesial and distal surface. The microgaps before and after the loading were compared, no statistically significant difference was observed caused by the dynamic loading on the labial, palatal, mesial or distal surface. Statistically significant difference was observed between UCLA and titanium group and between UCLA and zirconia group on both before and after the loading(p<0.05). No statistically significant difference was found between titanium and zirconia group. Loadings for $10^5$ times did not show significant effect to the microgaps between implants and abutments.

Transparent Insulation and Energy Saving in a School Building (학교건물(學校建物)의 에너지절약(節約)과 투명단열재(透明斷熱材))

  • Lee, Sung
    • Journal of the Korean Institute of Educational Facilities
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    • v.2 no.2
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    • pp.17-25
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    • 1995
  • Because of energy crisis and environment pollution, we have become more conscious of the need to conserve heat in buildings. In response to this need. new requirements have been developed for insulation and other matters relating to energy consumption. Among others, more promising is to use the energy that is all around us in the dynamic forces of nature:the wind, tides, waves, rivers, geothermal hot spots, and the sun. The problem is that we have not been forced to find the technological means to convert these natural energies into usable forms because it has been too easy simply to dig or pump our energy out of the ground. Now, the problem is not a shortage of energy itself, but a shortage of technology for converting the energy that lies aoo around us into usable forms. Energy-conversion technology is the real issue, and solar energy is one of the brightest and most promising frontiers in energy conversion. All buildings are wrapped in a skin. Generally skins protect the person in stay from rain, wind, dust, noise, cold, hot etc.. However, there are some skins that provide energy from given environment into the building. Out of aoo, transparent insulation material is one of these materials that most effectively satisfies this kind of envelope function. Since, there are no research on transparent insulation in Korea, it has been studied very actively in Europe and in America. Thus, in this thesis, we will theoratically study and analyze how the heat flows through a trans arrent insulated opaque wall of a school building in Korea. It will be an important information for the effective using guidelines of transparent insulation materials in Korea.

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The Fashion Communication Media and the Beauty of Ideal Body (II)- Focusing on the Beauty of Body - (패션 커뮤니케이션 매체와 이상적 신체미(제2보)- 신체미를 중심으로 -)

  • 김소영;양숙희
    • Journal of the Korean Society of Costume
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    • v.52 no.8
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    • pp.41-54
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    • 2002
  • This study discusses the beauty of the ideal body shown by fashion communication media, and explains how aesthetic aspects of, the body are being expressed in contemporary fashion. The beauty of the body may be considered as the beauty of sexual, controllable or consumable object. First. the most vigorously discussed point about the body is its sexual aspect, the most outstanding of which is the voluptuous and the androgynous beauty in contemporary fashion. Second, the body is an object which has been oppressed or controlled under the name of history. morality. and rationality. The things making us regard the body itself as an aesthetic object may be considered as dynamic and functional beauty Third, the sexual instinct and the body are fetishized as consumer goods, and women's bodies are presented as comsumer objects whose most parts could be restored to exchangeable value. The consumable beauty presented in contemporary fashion is the conspicuous beauty and the decadent beauty. So far, the various aspects of the beautiful body has been considered, based on the beauty of the ideal body shown by the fashion communication media. Man exists through on his body. but it is the embodied and formed body that serves as a means to manifest his social status and cultural ties. A natural body is reformed as a cultural phenomenon in various artificial ways. Popular culture has transmitted a series of new body image by creating and reproducing symbols and images, and has made the ideal body. Now there is not only one standard for the ideal beauty in our society. The standard of the beauty has changed continuously. There has been an aesthetic sense which can represent the times during the process of those changes. The various communication media have played a role of mirror reflecting those changes. The ideal body in contemporary times is no more an abstract media to express classical beauty, but an object directly affecting us, who are living in the crisis of subjectivity and identity.

Theory of NMR Spectoscopy and Its Application in Geoenvironmental Sciences (NMR 분광법의 원리와 지구환경과학에의 응용)

  • 김영규
    • The Journal of the Petrological Society of Korea
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    • v.10 no.3
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    • pp.233-245
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    • 2001
  • With the advent of super-conducting magnet, NMR spectroscopy becomes a very important tool in geology as well as in chemistry. $^{29}Si$ and $^{27}Al$ which are the main components of minerals and contain structural informations, are useful major targets for the NMR study in geology, but some other elements including alkali cations such as $^{23}Na$ are also one of them. NMR can be applied to many different fields. For example, it can be applied to study smaller range of structure (in molecular level) than XRD and TEM. NMR provides us with structural informations such as order-disorder in Al and Si distribution, oxygen coordination number, and distribution of other cations. Another important information that we can obtain from NMR is not only the static structural informations, but also the molecular dynamics. This dynamic informations of molecules also enable us to figure out the frequency of molecular motion and activation energy. Structure of amorphous minerals and chemistry and structure of natural organic materials are also studied by NMR.

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The Features of the Baroque Architecture viewed through the "Le Pli" of Deleuze (들뢰즈의 "주름 : Le Pli"을 통해 본 바로크 건축의 특성)

  • Lee, Young-Mi;Cheon, Deuk-Youm
    • Journal of architectural history
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    • v.17 no.6
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    • pp.7-27
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    • 2008
  • The primary object of this study lies in reilluminating the meaning of the Baroque, through studying arts and architecture by means of the features of Baroque aesthetics suggested by Deleuze in his writing 'Le Pli' on the basis of Leibniz's 'Pli' concept. Through this study we can see the following. In the first place, the six features - pli, separation between the inner and the exterior, highs and lows, unfolding, texture and paradigm presented as the features of Baroque aesthetics - have to be understood not as being independent features but as those derived from a series of continuous process of folding and unfolding. In the second place, Deleuze's thinking ranging from the 'Pli' of the Baroque to the paradigm derived on the ground of Leibniz thinking is a dynamic world of folding and unfolding, ultimately seeking unity through the topological changes and succession repeating deterritorization and reterritorization. In the third place, most architectural trends claiming 'Fold Architect' or the 'Pli' of Deleuze as their architectural philosophy are committing errors of mass-producing standardized designs by confining the meaning of Deleuze's 'Pli' concept into a simple reproduction of plied superficial things. With this finding in mind, the concept of folding and unfolding examined through reilluminating the Baroque Architecture where the 'Pli' concept is embodied, suggests to us that the problems of contemporary architecture should be rightened, and shows us that it can become an architectural philosophy which can be concretely realized in architecture.

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Modeling & Simulation Framework for the Efficient Development of a Rescue Robot (효율적인 구조로봇 개발을 위한 통합 M&S 프레임워크)

  • Park, Gyuhyun
    • Journal of the Korea Society for Simulation
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    • v.28 no.2
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    • pp.149-158
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    • 2019
  • This paper introduces an integrated Modeling & Simulation framework for the efficient development of the rescue robot which rescues a wounded patients or soldiers and disposes a dangerous objects or explosive materials in the battlefields and disastrous environments. An integrated M&S(Modeling & Simulation) framework would have enabled us to perform the dynamic simulation program GAZEBO based Software-in-the-Loop Simulation(SILS) which is to replacing the robot platform hardware with a simulation software. An integrated M&S framework would help us to perform designing robot and performance validation of robot control results more efficiently. Furthermore, Tele-operation performance in the unstructured environments could be improved. We review a case study of applying an integrated M&S framework tool in validating performance of mobility stabilization control, one of the most important control strategy in the rescue robot.

Dynamics of Honeymoon and Statics of Structure: Changes and Continuity of Foreign Policy in the Moon Jae-In Administration (하니문의 동학(動學)과 구조의 정학(靜學): 문재인 정부의 외교정책, 변화와 연속성)

  • Choi, Jinwoo
    • Korean Journal of Legislative Studies
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    • v.24 no.2
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    • pp.5-38
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    • 2018
  • A seismic change is under way in diplomatic topography surrounding the Korean Peninsula. A new dynamic is being generated that could lead to a breakthrough in the nuclear stalemate and to an end of hostility between the two Koreas. Moon Administration's bold and creative foreign policy, which is alleged to place South Korea in the "driver's seat", is probably responsible for what is happening on the Korean Peninsula. However, on the other hand, Moon Administration's foreign policy shows a lot of continuity with foreign policy of previous conservative governments. In particular, the Moon government's emphasis on the vitality of the ROK-US alliance and its commitment to close coordination with the US in dealing with nuclear issues of North Korea is the hallmark of the continuity in South Korea's foreign policy. Emphasizing and sharing the notion of the continuities in foreign policy could contribute to social integration by garnering bi-partisan support. It could also spawn sense of stability, predictability, and confidence to diplomatic counterparts in other countries. And it could help avoid the negative effects of expectation-reality gap in the event that the outcome of all the diplomatic endeavor falls short of expectation held by citizens.