• Title/Summary/Keyword: Critical Theory

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Finite Element Modelling of Axially Compressed GFRP Cylindrical Panels (축방향으로 압축을 받는 GFRP 원통형 판넬의 유한요소 모델링)

  • Kim, Ki Du
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.4
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    • pp.15-25
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    • 1993
  • In order to promote the efficient use of composite materials, effort is currently being directed at the development of design criteria for composite structures. Insofar as design against buckling is concerned, it is well known that, for metal shells, a key step is the definition of 'knockdown' factors on the elastic critical buckling stress accounting mainly for the influence of initial geometric imperfections. At present, the imperfection sensitivity of composite shells has not been explored in detail. Due to the large number of parameters influencing buckling response (considerably larger than for isotropic shells), a very large number of tests would be needed to quantify imperfection sensitivity experimentally. An alternative approach is to use validated numerical models for this task. Thus, the objective of this paper is to outline the underlying theory used in developing a composite shell element and to present results from a validation exercise and subsequently from a parametric study on axially loaded glass fibre-reinforced plastic (GFRP) curved panels using finite element modelling. Both eigenvalue and incremental analyses are performed, the latter including the effect of initial geometric imperfection shape and amplitude, and the results are used to estimate 'knockdown' factors for such panels.

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Governance Structure for Knowledge Transfer in Global Business Process Outsourcing (글로벌 프로세스 소싱에서의 효과적인 지식이전을 위한 거버넌스 구조 연구)

  • Kim, Gyeung-Min
    • Information Systems Review
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    • v.9 no.2
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    • pp.1-14
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    • 2007
  • The structure chosen to govern knowledge transfer in Inter Organizational Relationship(IOR) is often argued to be critical to the success of IOR. However, little research is done on the effective governance structure for knowledge transfer in global Business Process Outsourcing(BPO). The objective of this study is to explore the effective governance structure for knowledge transfer in IT intensive global BPO. Ground theory building methodology is used for this study. First, a generic framework on governance structure for knowledge transfer is derived from extant literature. The framework consists of potentially important constructs to study the governance mechanism for knowledge transfer. For the governance mechanism, this study focused on hierarchy/market structure, formal/informal control mechanisms and information systems. For knowledge type, the study focuses on sensitive knowledge, codifiable knowledge and non codifiable knowledge. This framework is applied to case analyses of two firms to explore effective governance mechanism to transfer each type of knowledge. As results of this study, pertinent propositions for future academic inquiry are derived.

A Study on the Color Characteristics of Japanese Ethnic Look in Contemporary Fashion (현대 패션에 나타난 일본풍 에스닉 룩의 색채 특성 -2004년 S/S부터 2008년 F/W까지-)

  • Kim, Ji-Young;Kim, Ji-Eon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.11
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    • pp.1750-1759
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    • 2008
  • The purpose of this study was to comparatively analyze the color characteristics of the Japanese ethnic look advanced by Japanese and western designers in comparison with the actual traditional colors of Japan. The data determining the traditional colors of Japan was collected through a critical apparatus examination of 250 colors and the color data of what determines Japanese ethnic look was collected through an analysis of the clothing appearing in four fashion collections -Paris, Milan, London, and New York- from the 2004 S/S collections to the 2008 F/W collections. For the analysis of these colors, Photoshop was used with an RGB value measuring under 300dpi resolutions. The RGB values were then converted to H V/C values through Munsell Conversion 8.0.3, and they were analyzed using Munsell's 40 Hue and PCCS. The results of this study are as follows: Japanese designers are expressing their own aesthetic theory by designing fashions in traditionally Japanese hues. However, neutral colors and low-chroma tones appear more often than traditional colors. This study illustrates how these designers use color to reflect their inside ideals being oversensitive traditonal ideals. In contrast, western designers reflect more contemporary trends through the use of hues that more clearly reveal their preconception of the colors of the Orient rather than actual traditional Japanese colors. Moreover, these foreign designers tend to approach fashion design by the means of shape rather than color. Japanese designers systematically analyze and apply their own culture to contemporary fashion design. Their efforts serve as a good reference model for research on traditional culture and fashion design.

Effects of Cockpit Display and Control Complexity on Pilot Situation Awareness (조종실 계기 및 제어 복잡성이 조종사의 상황인식에 미치는 영향)

  • Kim, Min-Young;Seol, Jae-Wook;Kim, Yong-Seok;Sohn, Young-Woo
    • Science of Emotion and Sensibility
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    • v.6 no.3
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    • pp.73-87
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    • 2003
  • This research extends a general theory of human cognition to an applied domain of piloting skills. We examined how fast and accurately pilots achieve and maintain situation awareness in flight by measuring their consistency judgment between a written statement describing a flight situation and a cockpit display showing a current state of an aircraft. The goal of this research is to determine whether situation awareness is influenced by expertise level as a Auction of two different kinds of flight situation variables. It was revealed that flight situation variables representing relations between flight elements had an effect on situation awareness. Working memory was found to play a critical role in integrating a variety of flight information form multiple sources. It was also revealed that flight situation variables representing the contents of flight elements had influence on situation awareness in flight. These results were explained in a theoretical framework of a construction-integration model to reveal the cognitive processes underlying situation awareness in flight.

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The Father's Role and Father-Child Interaction: A Review of Literature (아버지-아동관계에 관한 이론적 고찰 - 아버지의 역할 및 아버지-아동의 상호작용을 중심으로 -)

  • Wui, Yeong Hee
    • Korean Journal of Child Studies
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    • v.4
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    • pp.23-35
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    • 1983
  • The purpose of this study is to systematize the theory of the father-child relationship by analyzing the father's role and father-child interaction. The results of this study are as followings: (1) The oedipal period 3 to 5 years is a critical in development of the father-child relationship. Father absence is assumed in infancy but it is denying because the father participates in Child- rearing activity. (2) The Father's role is symbolized instrumental role traditionally and culturally but it is appropriate that we think the father's role to be androgynous concepts. Instrumental role as well as expressive role is expected to father's role. (3) The role of the father is supplementary mother's role. The father provides economic, emotional support and helps the balanced child- rearing. This indirect role of the father is very important. (4) The father influences child development, and his role is to be sex-role model to contrieve personality internalize moral development. But it is needed more empirical study to clarify father's effects on child development. (5) The amount of time that fathers spend with their children is less than mothers, but it is not assumed that difference of this amount of time do not differently influence to the children. (6) There are much similarity that difference between father-child interaction and mother- child interaction. Qualitative difference in interaction is response style. A responsive style of the father is physical intellectual instructive but mother's is verbal. (7) The effects of the father to a child must be analyzed on dyadic dimension and triadic dimension of family network. In triadic dimension, father influences mother- child relationship, mother to response sensitively, husband-wife relation.

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Structural health monitoring of high-speed railway tracks using diffuse ultrasonic wave-based condition contrast: theory and validation

  • Wang, Kai;Cao, Wuxiong;Su, Zhongqing;Wang, Pengxiang;Zhang, Xiongjie;Chen, Lijun;Guan, Ruiqi;Lu, Ye
    • Smart Structures and Systems
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    • v.26 no.2
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    • pp.227-239
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    • 2020
  • Despite proven effectiveness and accuracy in laboratories, the existing damage assessment based on guided ultrasonic waves (GUWs) or acoustic emission (AE) confronts challenges when extended to real-world structural health monitoring (SHM) for railway tracks. Central to the concerns are the extremely complex signal appearance due to highly dispersive and multimodal wave features, restriction on transducer installations, and severe contaminations of ambient noise. It remains a critical yet unsolved problem along with recent attempts to implement SHM in bourgeoning high-speed railway (HSR). By leveraging authors' continued endeavours, an SHM framework, based on actively generated diffuse ultrasonic waves (DUWs) and a benchmark-free condition contrast algorithm, has been developed and deployed via an all-in-one SHM system. Miniaturized lead zirconate titanate (PZT) wafers are utilized to generate and acquire DUWs in long-range railway tracks. Fatigue cracks in the tracks show unique contact behaviours under different conditions of external loads and further disturb DUW propagation. By contrast DUW propagation traits, fatigue cracks in railway tracks can be characterised quantitatively and the holistic health status of the tracks can be evaluated in a real-time manner. Compared with GUW- or AE-based methods, the DUW-driven inspection philosophy exhibits immunity to ambient noise and measurement uncertainty, less dependence on baseline signals, use of significantly reduced number of transducers, and high robustness in atrocious engineering conditions. Conformance tests are performed on HSR tracks, in which the evolution of fatigue damage is monitored continuously and quantitatively, demonstrating effectiveness, adaptability, reliability and robustness of DUW-driven SHM towards HSR applications.

Excrement and Subversion: Challenging the Authority and Values through Excrements in Contemporary Art (배설과 전복: 권위와 가치에 대한 도전으로 보는 현대미술에서의 배설)

  • Rhee, Jieun
    • The Journal of Art Theory & Practice
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    • no.13
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    • pp.133-156
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    • 2012
  • This paper briefly charts the history of excrement as part of the late 20th-century art and explores ways in which excrement functions in the realms of 'High' art. From Piero Manzoni's to David Hammons' performance , excrement has taken a small yet distinctively important part in the development of contemporary art. In an attempt to challenge the hegemony of 'high' art, on the one hand, and resist the commercialization and fetishization of art, on the other, Manzoni allegedly offered his own "shit" preserved in a tin can and sold it at the price of gold of the same weight. Andy Warhol took the legendary Abstract-Expressionist painter Jackson Pollock as the object of parody, simulating Pollock's dripping action by pissing onto the canvas that had been primed with copper-based paint. Warhol's urination produced splashes and stains of iridescent colors just as the patterns on ordinary abstract paintings. In contrast to Pollock's masculine action, Warhol's pissing alludes to the artist's homosexuality. Excrements in art also provoked controversies, debates, and even acts of vandalism against the artworks. The works of Andres Serrano and Chris Ofili infuriated many Christians for the blasphemous use of excrement with religious icons. Politicians engaged in the heated debates on the use of public and national funds in support of some of the 'politically incorrect' contemporary art. In the midst of media sensation and criticisms, these works challenged the conventional understanding of artistic beauty. The preexisting artworks were also targeted. African-american artist Hammons assumed the role of spectator in by urinating on Richard Serra's sculpture in the street of New York City. It was an act condemnation levelled at the racist pattern of the way in which large portions of funds and commisions of "public" art tended to promote established 'white' artists, whose work or creative process often failed to reflect the actual public. The use of excrement in art is not unusual in contemporary art practices. With its subversive power, excrement plays an important critical roles in the shaping of contemporary art.

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Analysis on Ego State Types of Public Librarians by Ego-gram in Korea (이고그램을 이용한 공공도서관 사서의 자아 상태 유형 분석)

  • Song, Gi-Ho
    • Journal of Korean Library and Information Science Society
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    • v.46 no.2
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    • pp.29-48
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    • 2015
  • The aim of this study is to analyze the functional ego state of public librarians who should take a role of an information intermediary for children and young adults through the ego-gram which is suggested in transactional analysis theory and review their limit and feasibility as instructors. As a result of analysis, the whole ego state type of public librarians is founded to be N-type(Nightingale type) like NP-AC-A-CP-FC. The characteristics of this type can be interpreted as 'to show the tendency of self-denial in spite of their dedication.' So, the public librarians have to do their best to develop A(Adult), CP(Critical Parent) and FC(Free Child) ego state to take the requirements and behaviors of children and young adults in nurturing attitudes and enhance their autonomy and creativity through active mutual interaction. Improving A and FC is also very helpful to decrease their stress and raise their job satisfaction.

Correlation Between Mechanical Behavior and Electrical Resistance Change in Carbon Particle Dispersed Plastic Composite

  • Song, D.Y.;Takeda, N.;Kim, J.K.
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.377-382
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    • 2001
  • Mechanical behavior and electrical resistance change of CPDP (carbon particle dispersed plastic) composite consisting of epoxy resin and conductive carbon particle were investigated under monotonic loading and repeated loading-unloading. The electrical resistance almost linearly increased with increasing strain during loading and the residual electrical resistance was observed even after removing load. The value of the residual electrical resistance was dependent on the maximum strain under the applied stress. This result suggests that the estimation of maximum strain (i.e., damage) is possible by the measuring electrical resistance of composite. The behavior of electrical resistance change during and after loading was discussed on the basis of the results of microscopic deformation and fracture observation. Moreover, the relationship between the volume fraction of carbon particle and the electrical resistivity of CPDP was investigated in relation to the percolation theory. Simulation model of percolation structure was established by Monte Carlo method and the simulation result was compared to the experimental results. The electrical resistance change under applied loading was analyzed quantitatively using the percolation equation and a simple model for the critical volume fraction of carbon particle as a function of the mechanical stress. It was revealed that the prediction was in good agreement with the experimental result except in the region near the failure of material.

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Application Behavior-oriented Adaptive Remote Access Cache in Ring based NUMA System (링 구조 NUMA 시스템에서 적응형 다중 그레인 원격 캐쉬 설계)

  • 곽종욱;장성태;전주식
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.9
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    • pp.461-476
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    • 2003
  • Due to the implementation ease and alleviation of memory bottleneck effect, NUMA architecture has dominated in the multiprocessor systems for the past several years. However, because the NUMA system distributes memory in each node, frequent remote memory access is a key factor of performance degradation. Therefore, efficient design of RAC(Remote Access Cache) in NUMA system is critical for performance improvement. In this paper, we suggest Multi-Grain RAC which can adaptively control the RAC line size, with respect to each application behavior Then we simulate NUMA system with multi-grain RAC using MINT, event-driven memory hierarchy simulator. and analyze the performance results. At first, with profile-based determination method, we verify the optimal RAC line size for each application and, then, we compare and analyze the performance differences among NUMA systems with normal RAC, with optimal line size RAC, and with multi-grain RAC. The simulation shows that the worst case can be always avoided and results are very close to optimal case with any combination of application and RAC format.