• Title/Summary/Keyword: continuity theory

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Modification of the Cubic law for a Sinusoidal Aperture using Perturbation Approximation of the Steady-state Navier-Stokes Equations (섭동 이론을 이용한 정상류 Navier-Stokes 방정식의 주기함수 간극에 대한 삼승 법칙의 수정)

  • 이승도
    • Tunnel and Underground Space
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    • v.13 no.5
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    • pp.389-396
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    • 2003
  • It is shown that the cubic law can be modified regarding the steady-state Navier-Stokes equations by using perturbation approximation method for a sinusoidal aperture variation. In order to adopt the perturbation theory, the sinusoidal function needs to be non-dimensionalized for the amplitude and wavelength. Then, the steady-state Navier-Stokes equations can be solved by expanding the non-dimensionalized stream function with respect to the small value of the parameter (the ratio of the mean aperture to the wavelength), together with the continuity equation. From the approximate solution of the Navier-Stokes equations, the basic cubic law is successfully modified for the steady-state condition and a sinusoidal aperture variation. A finite difference method is adopted to calculate the pressure within a fracture model, and the results of numerical experiments show the accuracy and applicability of the modified cubic law. As a result, it is noted that the modified cubic law, suggested in this study, will be used for the analysis of fluid flow through aperture geometry of sinusoidal distributions.

An Analysis of Spactial Practice of Morden People appeared in the early 20th century film (20세기 초 영화에 나타난 근대인의 공간적 실천 분석 연구)

  • Lee, Young-Soo;Roh, Eun-Joo
    • Korean Institute of Interior Design Journal
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    • v.20 no.6
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    • pp.124-134
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    • 2011
  • The space has been interpreted from various perspectives, such as hierarchical, cultural, economic, political factors, etc. So we can see the space as a social existence. Space is now being formed through the dialectical relations of these elements. From this point of view, this study started to research the spatial practice of morden people through the case in the early 20th century film. With the discourse of Henri Lefebvre and David Harvey, and Michel de Certeau's theory, this research tried to find the mechanisms of spatial practice. Also Benjamin is a philosopher who intervenes the relationship between modernity and cultural production and his way of reading cultural phenomena seems to serve as the useful methodology of cultural studies. Modern people were individual unawared of the era, awakened to the ego. They were wandering the room and the street, private and public places. They were city dwellers walking around, collecting goods, and living of everyday life. Spatial practice is a fixed activity and have continuity. spatial practice appeared in the early 20th century film is at the intersection of social practices and the practice of everyday life. Social practices are a fixed practice and continuous practice. The practices of everyday life are nomadic practice and amusable practice. Modern people accommodate and adapt to a given space of the city through fixed practice. They realizes the access and the distance from spaces through continuous practice. They select and approved the spaces through nomadic practice. And they possess exclusively and utilize the spaces through amusable practice. Through These research spatial practices, it could easily found similarities and differences between modern space on the early 20th century and contemporary space of 21st century. True modern is not the past but the present.

A User-Level File System for Streaming Media Caching (스트리밍 미디어 캐슁을 위한 사용자 수준 화일 시스템)

  • Oh, Jae-Hak;Cha, Ho-Jeong
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.8
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    • pp.472-483
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    • 2002
  • This paper presents the design and implementation of a cache file system, umcFS, which is specifically designed to provide an efficient caching and transmission of streaming media. The proposed file system is based on the concept of file disk and implemented as an application level on top of a general-purpose file system. The file disk favors the continuity of cached media and provides an efficient I/O mechanism for cache server. umcFS statically allocates control blocks as well as media cache blocks. These blocks are referenced by the single-level indirect management structure. As the file system is designed as an application level, it is easy to develop and port to other systems. The performance of the implemented system shows that umcFS performs about 13% better than the native file system in randomly accessing the cache blocks of 1024KB.

The use of the strain approach to develop a new consistent triangular thin flat shell finite element with drilling rotation

  • Guenfoud, Hamza;Himeur, Mohamed;Ziou, Hassina;Guenfoud, Mohamed
    • Structural Engineering and Mechanics
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    • v.68 no.4
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    • pp.385-398
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    • 2018
  • In the present paper, we offer a new flat shell finite element. It is the result of the combination of a membrane element and a bending element, both based on the strain-based formulation. It is known that $C^{\circ}$ plane membrane elements provide poor deflection and stress for problems where bending is dominant. In addition, they encounter continuity and compliance problems when they connect to C1 class plate elements. The reach of the present work is to surmount these problems when a membrane element is coupled with a thin plate element in order to construct a shell element. The membrane element used is a triangular element with four nodes, three nodes at the vertices of the triangle and the fourth one at its barycenter. Each node has three degrees of freedom, two translations and one rotation around the normal. The coefficients related to the degrees of freedom at the internal node are subsequently removed from the element stiffness matrix by using the static condensation technique. The interpolation functions of strain, displacements and stresses fields are developed from equilibrium conditions. The plate element used for the construction of the present shell element is a triangular four-node thin plate element based on Kirchhoff plate theory, the strain approach, the four fictitious node, the static condensation and the analytic integration. The shell element result of this combination is robust, competitive and efficient.

Pronoun Resolution in French Discourse by Korean-learners of French (한국인 프랑스어 학습자의 프랑스어 담화 이해와 대명사 해석 연구)

  • Ahn, Eui-Jeen;Song, Hyun-Joo;Kim, Min-Ju;Leem, Jai-Ho
    • Korean Journal of Cognitive Science
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    • v.25 no.4
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    • pp.417-433
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    • 2014
  • This research examined whether Korean-learners of French were sensitive to discourse structure in anaphoric pronoun resolution. In the experiments, participants read three-sentenced stories and made judgements about how the last sentence of each story makes sense in relation to previous two sentences on a 7-point Likert scale. The stories differed in whether the subject of the last sentence continued the subject of the preceding sentence, and whether the subject of the last sentence was mentioned with a pronoun or a proper noun. The results from French participants replicated the patterns shown in previous studies. In contrast, Koreans exhibited greater difficulty in interpreting pronoun-subject sentences than noun-subject sentences regardless of subject continuity. These findings are discussed within the context of developmental perspective, which suggests the processing of co-referential interpretation may interact with language proficiency.

A Study on the Meaning of Myth and Sign in the Matter of Cultural Modernization of Architecture - focused on the thinking of Ernst Cassirer and Charles Sanders Peirce - (건축의 문화적 현대화에 있어 신화와 기호의 의미에 관한 연구 -철학가 카시러와 기호학자 퍼스의 사유방식을 중심으로-)

  • Byun, Tae-Ho
    • Journal of architectural history
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    • v.12 no.4 s.36
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    • pp.49-62
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    • 2003
  • Vesely explains, the main source of our confusion and nihilism comes most probably from the ambiguous relationship between modem architecture, technology and aesthetics. Also, to overcome such crucial problems, many theorists recently emphasize to take part in cultural civilization and to preserve creative genes of great culture that is based on our interpretation of 'ethical and mythical nucleus of mankind,' rather than in technical modernization that constitutes a sort of subtle destruction of mytho-ethical nucleus of a society. They for architecture also strongly stress on a mythopoetic imagination and an ontological construction of building, which could make a form symbolic and mythical rather than mathematical and aesthetic representation. On this point, 'myth' becomes a vital idea for constructing and construing architectural form and space. And it is also one of the essential concepts to understand both the motive power of cultural continuation of place and the meaning of architecture. Nevertheless, its meaning and the citation of word in architectural essay are still obscure. It might be because the original concept of myth not only has been lain in the matter of philosophical contemplation. Thus, the intention of the research is focused on lightening the meaning of myth in architectural term. Especially, it is, first, concentrated on interpreting philosopher Ernst Cassirer's reflections which were written in order to emphasize the importance of 'mythical consciousness' for the world's cultural civilization. And, the second, it will continue to interpret the myth as a sign within the semiotic concept of Charles Sanders Peirce, and further to emphasis the significance of mythic signs for the continuance of artistic and cultural idea including architecture. The contents of the paper is not that of architectural planning and design methodology, rather architectural philosophy and epistemology. Nevertheless, in regard to architecture, the research will, against today's un-discriminated use of symbolic motifs and instrumental representation of form, suggest a concrete architectural and aesthetic theory of myth and sign, especially of the relationship between the idea of semiology and the function of cultural continuity.

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Determinants of perceptual switching costs for digital game: focused on the different effects of basic psychological needs satisfaction (게임 전환 비용의 결정 요인: 모바일 게임 사용자의 기본적 심리 욕구 충족 차이를 중심으로)

  • Kim, Young-Berm;Lee, Sang-Ho
    • Journal of the Korea Convergence Society
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    • v.11 no.1
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    • pp.131-139
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    • 2020
  • Gamers switch their games to a new when get bored or encounter more attractive ones. Switching cost varies by gamers and depends on how they are satisfied with their current game. This study evaluates the satisfaction with current games as the miltiple basic psychological need in the self-determination theory and suggests 'needs-costs' causality research model that explain the variety of gamer's switching behavior. As the empirical test to domestic mobile gamers, the autonomy fulfillment to current game affect reversely with those of autonomy and relatedness. Those relationships between need satisfaction and perceptual switching cost vary according to their age and game genre preference. The results would be applied to understand gamers' switching behavior.

A Wave Propagation Analysis in the Layered Systems (적층계(積層係)를 통과하는 소성응력파(塑性應力波)의 전파(傳波))

  • Lee, Sang Ho;Ahn, Byoung Ki;Kang, Young Goo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.2
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    • pp.61-71
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    • 1993
  • The stress waves generated by the mechanical energies by impact or the chemical energies by the explosions are transmitted through medium. The wave propagation process through medium is a very complicated procedure due to the reflections and refractions of the waves at the free surfaces and interfaces. In this study the pressure independent Von-Mises model is employed for the wave propagation analysis in the layered systems. Governing equations of this study are conservation equations of momentum and mass in Lagrangian coordinate system which is fixed to the material. Due to the shock-front which violates the continuity assumptions inherent in the differential equations numerical artificial viscosity is used to spread the shock front over several computational zones. These equations are solved by Finite Difference Method with discretized time and space coordinates. The associate normality flow rule as a plastic theory is implemented to find the plastic strains.

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A Study on the Accuracy of GPS Received Data in Travel Vehicle (통행차량에 대한 GPS수신자료의 정확도에 관한 연구)

  • Kim, Jae-Seok;Lee, Seung Jun;Woo, Yong-Han
    • Journal of the Korean Association of Geographic Information Studies
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    • v.5 no.4
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    • pp.75-85
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    • 2002
  • The introduction of GPS technique in transportation study make real time tracking of driving vehicle's position possible. Position information data gauged with three dimension(X, Y, Z) can be achieved with time-continuity and from more than two driving vehicles. For this field of study, in past day, there were many difficulties in collecting real time data, but now, it becomes easy thanks to this. But for the resonable result analysis, fully understanding of GPS data-accuracy must be proceeded. Because accompanied magnitude of error depends on the study's accuracy. For this reason, this study surveyed the GPS data's error and suggest calibrate technique. This study's result will be helpful for following studies using DGPS data. For this, this study takes two types study in road, and set triangulation coordinates, and compare it with GPS data. DGPS data contains less than 0.6m's error.

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A Plastic Analysis of Structures under the Impact Loading (충격하중(衝擊荷重)을 받는 구조물(構造物)의 소성(塑性)모델에 따른 거동분석(擧動分析))

  • Ahn, Byoung Ki;Lee, Sang Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.2
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    • pp.21-33
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    • 1992
  • Under the intense-impulsive loading, structures are subjected to the wide range of pressures at an instantaneous time. The constitutive laws capable to describe the material behavior under the extreme pressure as well as the low pressure are necessary for the analysis of the structural behavior under the intense -impulsive loadings. In this study, two plastic models, the pressure independent Von-Mises model and the pressure dependent Drucker-Prager model, are employed for the wave propagation analysis. Governing equations of this study are conservation equations of momentum and mass in Lagrangian coordinate system which is fixed to the material. Due to the shock-front which violates the continuity assumptions inherent in the differential equations numerical artificial viscosity is used to spread the shock front over several computational zones. These equations are solved by Finite Difference Method with discretized time and space coordinates. The associate normality flow rule as a plastic theory is implemented to find the plastic strains.

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