• Title/Summary/Keyword: 무한체

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Conductive-Radiative Heat Transfer in an Infinite Square Duct with Dielectric Directional Property Wall (부도체 방향복사면이 있는 무한 정사각관의 전도-복사열전달)

  • Byun, Ki-Hong;Im, Moon-Hyuk
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.5
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    • pp.543-552
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    • 2003
  • The effects of a directionally emitting and reflecting dielectric surface on the wall heat flux and medium temperature distribution are studied. The system is an infinite square duct enclosing an absorbing and emitting medium. The emissivity and reflectivity of opaque and gray wall vary with direction. Combined effect of conductive and radiative heat transfer is analyzed using finite difference and the direct discrete-ordinates method. The parameters under study are conduction to radiation parameter, optical depth, refractive index ratio. The results with directional and diffuse properties deviate each other when the conduction to radiation parameter is less than around 0.01. The wall heat flux differs fur optical thickness less than around 0.1. However, the medium temperature profiles differ for optical thickness greater than around 1. Deviations from diffuse property calculations are larger for hot wall with directional property than cold wall with directional property. As n increases from 1.5, the trend changes are observed fur refractive index ratio about n=6.10

An Experimental Study on the Evaluation of Mechanical Properties of CFT Column by Unstressed Test and Stub Specimen (비재하 가열시험 및 Stub 시험체를 활용한 CFT기둥의 역학적 특성평가에 관한 실험적 연구)

  • Lee, Dae-Hee;Lee, Tae-Gyu;Lee, Eui-Bae;Kim, Young-Sun;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.05a
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    • pp.209-213
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    • 2008
  • Recently, it increases in use of CFT(Concrete filled steel tube, below CFT) because material and method are required to be diversification and High-Performance according to increase the super-high structure. But, CFT column lose bearing capacity under fire because steel tube is exposed to outside. As a result, structure is collapsed and then it cause much damage. In case of the Europe, Japan and America, they have studied the fire-resistance performance of CFT under fire for a long time. However, it would have hardly studied it in domestic because it is much difficulty about experiment machine and cost. So it is needed base on fire-resist performance of CFT under fire. Therefore, this study dynamic specificity of stub column which made tester of stub column based on facts of strength and mixing fiber evaluated used heating and load testing machine. As a result, it is willing to propose fundamental data for quick and accurate diagnosis of deteriorated concrete structure by fire damage with experiment according to the design high strength concrete.

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Effect for Steel Corrosion Protection in Concrete applying Surface Coating Anode and Solar Battery (표면(表面) 코팅 양극(陽極)과 태양전기(太陽電氣)를 이용한 콘크리트 중의 철근(鐵筋) 부식(腐食) 방지(防止)를 위한 효과)

  • Kim, Jong-Pil;Park, Kwang-Pil;Kim, Seong-Soo;Jung, Ho-Seop;Lee, Seung-Tae
    • Resources Recycling
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    • v.18 no.4
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    • pp.44-51
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    • 2009
  • In order to verify the effect of Surface Coating Anode and Solar Battery anode system, accelerated tests in the presence or absence of some chloride content and cracks were carried out. The potential-decay, protection potential and corrosion current density of reinforcing steel in concrete specimen were measured to evaluate the effectiveness of the system. From the test results, the application of the system led to the satisfaction on NACE's criterion in all mixtures of concrete. Additionally it was found that protection potential and corrosion current density were satisfied due to the application of Surface Coating Anode and Solar Battery anode system.

Investigation of helium injection cooling to liquid oxygen chamber (헬륨분사를 통한 액체산소 냉각의 이론적 고찰 및 해석과 시험의 비교)

  • Gwon, O-Seong;Jo, Nam-Gyeong;Jeong, Yong-Gap;Lee, Jung-Yeop
    • Aerospace Engineering and Technology
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    • v.5 no.2
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    • pp.134-142
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    • 2006
  • Sub-cooling of cryogenic propellant by helium injection is one of the most effective methods for suppressing bulk boiling and keeping sub-cooled liquid oxygen before rocket launch. In order to design the cooling system, understanding of the limitations of heat and mass transfer is required. In this paper, an analytical model for the helium injection system is presented. This model's main feature is the representation of bubbling system using finite-rate heat transfer and instantaneous mass transfer concept. With this simplified approach, the effect of helium injection to liquid oxygen system under several circumstances is examined. Experimental results along with simulations of single bubble rising in liquid oxygen and bubbling system are presented with various helium injection flow rates, and with change of oxygen chamber pressure.

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An Analysis of Electromagnetic Field Scattering for the Dielectric Cylinders (유전체주의 전자장 산란 해석)

  • 박동희;김정기
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.2
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    • pp.181-186
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    • 1992
  • The scattering property of TMz illuminated perfectly conducting and dielectric cylinders of arbitrary cross section are analyzed by the boundary element techniques. The boundary element equations are formulated via Maxwell’s equations, weighted residual or Green’s theorem, and the boundary conditions. The unknown surface fields on the boundaries are then calculated by the boundary element integral equations. Once the surface fields are found, the scattered fields in from a perfectly conducting circular and elliptic cylinders, a dielectric circular and elliptic cylinders are numerically analyzed. A general computer program has been developed using the quadratic elements(higher order boundary elements) and the Gaussian quadrature.

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Das Problem des Selbstbewußtseins Zwischen Vernunft und Existenz: Im Zentrum auf die Transformationen von Kants Selbstbewußtseinstheorie in Heideggers Analytik vom Dasein, Apels Lehre von diskursiver Vernunft, und Ebelings Lehre von Widerstandsbewußtsein (이성과 실존 사이에서 자기의식의 문제: 하이데거의 현존재 분석론, 아펠의 담론적 이성 이론, 그리고 에벨링의 저항의식 이론에서칸트의 자기의식 이론에 대한 변형들을 중심으로)

  • Kim, Chungjoo
    • Journal of Korean Philosophical Society
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    • no.120
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    • pp.217-250
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    • 2018
  • Subjekt oder $Selbstbewu{\ss}tsein$ ist ein grundlegendes Prinzip neuzeitlicher Philosophie. Das $Selbstbewu{\ss}tsein$ ist bei Kant $Selbstbewu{\ss}tsein$(analytische Einheit der Apperzeption als klare Selbstbeziehung) in Objekts $bewu{\ss}tsein$(synthetischer Einheit der Apperzeptuion). Dabei zeigt er ein Reflexionsmodell des $Selbstbewu{\ss}tseins$. Aber er $erkl{\ddot{a}}rt$ nicht systematisch ein $Verh{\ddot{a}}ltnis$ zwischen synthetischer Einheit und analytischer Einheit der Apperzeption, und auch $l{\ddot{o}}st$ er nicht theorienimmanente und formale Schwierigkeiten von Zirkelargument bzw. unendlicher Iteration in der Reflxionsstruktur des $Selbstbewu{\ss}tseins$. Aufgrund der Voraussetzungen seiner eigenen Fundamentalontologie kritisiert der $fr{\ddot{u}}he$ Heidegger, $da{\ss}$ Kants $traditionsabh{\ddot{a}}ngige$ $Subjektivit{\ddot{a}}tstheorie$ Symptome der Seins vergessenheit zeigt, transformiert Kants $Selbstbewu{\ss}tseinstheorie$, interpretiert Kants transformierte Theorie als $subjektivit{\ddot{a}}tstheoretische$ $Begr{\ddot{u}}ndung$ der traditionellen Ontologie von Vorhandenheit, und versteht sie als ersten Schritt und erstes phlosophisches Modell seiner Fundamentalontologie. Durch kritische Interpretation von Kants Lehre von Selbstaffektion und $Selbstbewu{\ss}tsein$ deutet er ein Modell des $Selbstbewu{\ss}tseins$ als des $ph{\ddot{a}}nomenologischen$ $Horizontsbewu{\ss}tseins$ an. In diesem Modell der vorreflexiven und unmittelbaren Selbstbeziehung entstehen Schwierigkeiten von Zirkelargument bzw. unendlicher Iteration nicht. Apel kritisiert Kants $selbstbewu{\ss}te$ Apperzeptionstheorie in dem Sinne, $da{\ss}$ sie solipsistisch sei, und in seiner Transzendentalpragmatik $vervollst{\ddot{a}}ndigt$ er Kants transzendentalphilosophische $G{\ddot{u}}ltigkeit$ in der Dimension von $Intersubjektivit{\ddot{a}}t$ diskurierender Menschen. Hierbei ersetzt die Kommunikationsgemeinschaft Kants Apperzeption oder $Bewu{\ss}tsein$ ${\ddot{u}}berhaupt$. In der transzendentalpragmatischen Sicht, die auf den sprachlichen Bezug des Denkens und Erkennens und die Kommunikationsgemeinschaft geht, beruht das $Selbstbewu{\ss}tsein$ oder die Reflexion des Subjekts wesentlich auf seinem sprachlich vermittelten sozialen Bezug. Also geht es nicht um Zirkelargument und unendliche Iteration in denkender Selbstbeziehung des Subjekts. Ebeling hebt Heideggers Daseinsanalytik auf das Niveau von Apels Transzendentalpragmatik an und entwickelt Fundamatalpragmatik ${\ddot{u}}ber$ $Widerstandsbewu{\ss}tsein$ gegen allgemeinen Tod. Dieser $Widerstandsbewu{\ss}tsein$ ist fundamentalpragmatische Transformation von Kants $Selbstbewu{\ss}tsein$. Der $Widerstandsbewu{\ss}tsein$ der Vernunft bleibt in der solipsistischen Dimension nicht und ist ein $Bewu{\ss}tsein$, das in der Widerstandsgemeinschaft durch Argumentation universalisiert werden kann. Hierbei geht es nicht um Zirkelargument und unendliche Iteration.

Interpretation of Finite HMD Source EM Data using Cagniard Impedance (Cagniard 임피던스를 이용한 수평 자기쌍극자 송신원 전자탐사 자료의 해석)

  • Kwon Hyoung-Seok;Song Yoonho;Seol Soon-Jee;Son Jeong-Sul;Suh Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.5 no.2
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    • pp.108-117
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    • 2002
  • We have introduced a new approach to obtain the conductivity information of subsurface using Cagniard impedance over two-dimensional (2-D) model in the presence of horizontal magnetic dipole source with the frequency range of $1\;kHz\~1\;MHz$. Firstly, we designed the method to calculate the apparent resistivity from the ratio between horizontal electric and magnetic fields, Cagniard impedance, considering the source effects when the plane wave assumption is failed in finite source EM problem, and applied it to several numerical models such as homogeneous half-space or layered-earth model. It successfully provided subsurface information even though it is still rough, while the one with plane wave assumption is hard to give useful information. Next, through analyzing Cagniard impedance and apparent resistivity considering source effect over 2-D models containing conductive- or resistive-block, we showed that the possibility of obtaining conductivities of background media and anomaly using this approach. In addition, the apparent resistivity considering source effect and phase pseudosections constructed from Cagniard impedance over the isolated conductive- and resistive block model well demonstrated outlines of anomalies and conductivity distribution even though there were some distortions came from sidelobes caused by 2-D body.

6th Industry Management Body Develop Managerial and Technical Level Metrics - by Applying AHP Analysis - (6차산업화 경영체 경영.기술수준 평가지표 개발 -AHP 분석을 적용하여-)

  • Seo, Yoon Jeong;Park, Jeong Woon;Han, Sang Yeon;Hwang, Dae Yong;Yang, Jung Hyun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.8 no.4
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    • pp.177-191
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    • 2013
  • 6th Industry reduced agricultural income and rural areas, the economic downturn is going to be activated is attracting attention as an alternative. 6th industry means that the integrated or linked, the manufacture and processing of secondary industry based on primary industry, the distribution and service of tertiary industry. Park Geun-hye government to realize the creative economy in agriculture as an alternative to specifically evaluate the 6th industries and suggests various policy alternatives. In addition, to support the development of models and analysis of best practices, including sleep studies are in progress. However, the 6th Industry management body for performing management level, technical level, the leader in comprehensive evaluation of competencies and indicators on the development of an evaluation study is insufficient. In this regard, the present study performed 6th industry management body for the management level, technical level, the leader competency evaluation indicators to develop a comprehensive evaluation by utilizing AHP method was developed indicators. The results achieved in Korea As different countries and the FTA as cheap agricultural imports increased 6th industry revenues associated with the management body is very likely to be worse. The endless competition to survive in the most important of the strategy for each individual project management body to operate on their own, rather than to strengthen internal capacity by strengthening linkages with other industries, products, and services that promote the sale will be. This also is that you need to improve revenue management body. Thus, all 6th industry management body at the location of their efforts to gain the trust of consumers will require, moreover, for each management body to build cooperation between the various measures will be sought. In addition to the smart era rapidly changing needs of customers, depending on the life cycle of products and services are getting faster and the new consumer is getting more and more tend to find new products. Thus, customers and management body 6th industry changes quickly and accurately predict market trends, and also to market new products and services that further efforts would be needed.

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Online WOM Communication of Crossmedia Storytelling (크로스미디어 스토리텔링의 온라인 구전 양상)

  • Seo, Seong-Eun
    • The Journal of the Korea Contents Association
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    • v.11 no.1
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    • pp.134-144
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    • 2011
  • Crossmedia Storytelling is receiving attention as a new style of description in the age of limitless competition and infinite fusion among media. Crossmedia Storytelling specifies a form of storytelling carried out through mixed usage of plural media, such as televisions, movies, and web services. It is different from OSMU strategy in that plays one source of contents according to the characteristics of various media while Crossmedia Storytelling demands users' active participation. Moreover, it is also slightly different from Transmedia Storytelling in the point that narratives of each media are not complete themselves and only through effectively combining plural media can the whole story fully enjoyed. This research aims to analyze how users move among media in terms of Crossmedia contents by examining cases of Swedish interactive drama series , from Australia, and from the United States. To do so, first, the paper looks into the principles of Crossmedia communication and examines that it is based on online word-of-mouth communication, such as viral marketing. As a result, the following was found in the cases of Crossmedia Storytelling: negative stories that arouse users' emotional reactions & users' participation are effective, and the set-up of Sneezer, which causes the knowledge gap, is very important. It was also found that users' participation was actively taking place through online WOM communication in Crossmedia Storytelling.

X-선 회절분석을 이용한 일라이트-스멕타이트 기본입자의 적층성에 관한 연구

  • 강일모;문희수
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2003.05a
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    • pp.10-10
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    • 2003
  • 일라이트-스멕타이트 혼합층광물(I-S)은 열역학적으로 상호 대립적인 두 가지 모델로 이해되고 있다. 첫째, MacEwan 결정자 모델은 I-S를 5-20개의 스멕타이트와 일라이트 층으로 구성된 결정자로 해석한다. 이러한 모델은 분산과 재응집 과정을 기초로 하는 X-선 회절분석(XRD)에서 기인한 것으로 Reynolds의 XRD 모델과 동일하다. 둘째, 기본입자 모델은 I-S를 물리적으로 분리될 수 있는 최소 입자인 기본입자가 $c^{*-}$축 방향으로 응집된 응집체로 해석한다. 이러한 모델은 분산 과정을 기초로 하는 주사전자현미경(TEM) 관찰에서 기인한 모델이다. 강일모 등(2002)은 이 두 가지 모델을 비교함으로써 1< $N_{F}$<100/% $S_{XRD}$ ( $N_{F}$=평균 기본입자 층개수, %$S_{XRD}$=XRD 분석을 통하여 측정된 팽창성)을 도출하였다. 이 식은 기본입자모델과 Eberl & Srodon(1988)이 제시한 최대 팽창성(%$S_{MAX}$)을 동시에 해석할 수 있게 해준다. %$S_{MAX}$는 XRD 모델에서는 고려하지 않는 I-S 결정자 상$\cdot$하부에 존재하는 두 개의 0.5nm 규산염층을 하나의 스멕타이트 층으로 간주하여 얻어진 팽창성이다. Srodon et al.(1992)은 %$S_{MAX}$=100/ $N_{F}$을 제시하였으며, 강일모 등(2002)은 %$S_{MAX}$는 기하학적으로 기본입자가 무한적층을 하였을 때 관찰되는 %$S_{XRD}$와 동일함을 밝힌 바 있다. 만약, XRD 분석을 위한 시료 준비과정에서 I-S 결정자가 분산되었다가 재응집을 한다면, XRD에서 관찰되는 결과는 일차적으로 기본입자의 적층성에 영향을 받게 된다. 따라서, 기본 입자의 적층성은 XRD 분석을 이용하여 I-S 구조를 해석하는데 매우 중요한 요인이다. 본 연구는 기본입자의 적층성을 정량화하기 위해 %$S_{XRD}$=A/ $N_{F}$ (0$S_{MAX}$=100/ $N_{F}$로부터 얼마나 벗어나 있는가는 지시해 준다 금성산화산암복합체에서 산출되는 11개 I-S 시료와 14개의 Drits et al.(1998) 자료로부터 1nA=-0.14 $N_{F}$+4.7의 실험식을 도출할 수 있었으며, 기본입자의 적층성은 일차적으로 기본입자의 두께에 의해 영향을 받는 것으로 관찰되었다. Nadeau(1985)는 기본입자두께분포로부터 I-S 결정자의 팽창성을 측정하기 위하여 Ps=$\Sigma$p(N)/N을 제시하였다(Ps=스멕타이트 층 비율, N=기본 입자 층개수, p(N)=N의 확율). 그러나 위식은 실질적으로 %$S_{MAX}$를 제공해주기 때문에 %$S_{XRD}$를 유추하는데는 부적합하다. 본 연구는 이를 변형하여 Ps=$\Sigma$p(N)A(N)/N을 제시하였다(A(N)=N에 대한 A값). 위의 실험식을 사용하여 헝가리산 Zempleni 시료(15%$S_{XRD}$)의 기본입자분포로부터 %$S_{XRD}$를 계산한 결과, 16%$S_{XRD}$의 결과값을 얻을 수 있었다. 따라서, 본 연구에서 도출한 관계식들이 유효함을 확인할 수 있었다.계식들이 유효함을 확인할 수 있었다.

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