• 제목/요약/키워드: cross concept

검색결과 539건 처리시간 0.033초

Zeroth-Order Shear Deformation Micro-Mechanical Model for Periodic Heterogeneous Beam-like Structures

  • Lee, Chang-Yong
    • 동력기계공학회지
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    • 제19권3호
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    • pp.55-62
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    • 2015
  • This paper discusses a new model for investigating the micro-mechanical behavior of beam-like structures composed of various elastic moduli and complex geometries varying through the cross-sectional directions and also periodically-repeated along the axial directions. The original three-dimensional problem is first formulated in an unified and compact intrinsic form using the concept of decomposition of the rotation tensor. Taking advantage of two smallness of the cross-sectional dimension-to-length parameter and the micro-to-macro heterogeneity and performing homogenization along dimensional reduction simultaneously, the variational asymptotic method is used to rigorously construct an effective zeroth-order beam model, which is similar a generalized Timoshenko one (the first-order shear deformation model) capable of capturing the transverse shear deformations, but still carries out the zeroth-order approximation which can maximize simplicity and promote efficiency. Two examples available in literature are used to demonstrate the consistence and efficiency of this new model, especially for the structures, in which the effects of transverse shear deformations are significant.

변단면 기둥의 자유진동 및 최소임계하중 해석 (Free Vibrations and First Critical Loads of Tapered Columns)

  • 이병구;오상진;모정만;김헌상
    • 소음진동
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    • 제2권3호
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    • pp.203-211
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    • 1992
  • The main purpose of this paper is to present both the natural frequencies and the first critical loads of tapered columns. The ordinary differential equation governing the free vibration for tapered columns under compressive axial force is derived. Three kinds of cross sectional shape are considered in the governing equation. The Runge-Kutta method and determinant search method are used to perform the integration of the differential equation and to determine the natural frequencies, respectively. Additionally, the bisection method is used to determine the critical loads. In numerical examples, the effects of compressive axial force on the natural frequencies of tapered columns are investigated varying the end conditions. The first critical loads of tapered columns are determined on the basis of dynamic concepts. The first critical loads of tapered columns are determined on the basis of dynamic concept. The effects of cross sectional shapes are shown and some typical mode shapes are also presented.

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임의 형상의 단면을 갖는 박판보의 유한요소 해석 (Finite Element Analysis of the Thin-Walled Beam with Arbitrary Cross Section)

  • 양웅필;신효철
    • 대한기계학회논문집A
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    • 제20권1호
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    • pp.100-114
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    • 1996
  • In this paper, a new thin-walled beam finite elcment is developed to overmome the difficulties in the analysis of real structures by existing beam elements. The element is formulated by extending Benscoter's assumption and also by adopting the concept of the curvature-based element. It is applicable to the analysis of the beams with arbitrary cross-sectional shapes. The results obtained show that the element is locking-free and the accuracy of the finite element solutions is remarkably improved.

엔드밀의 정적 강성에 관한 연구 (A Study on the Static Rigidity of the End Mill)

  • 이상규;고성림
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 추계학술대회 논문집
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    • pp.9-14
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    • 1996
  • The deflection of an end mill is very important in machining process and cutting simulation because it affects directly workpiece accuracy, cutting force, and chattering. In this study, the deflection of the end mill was studied both experimentally and by using finite element analysis. And the moment of inertia of radial cross sections of tile helical end mill is calculated for the determination of the relation between cross section and rigidity of tile tools. Using tile Bernoulli-Euler beam and and the concept of equivalent diameter, a deflection model is established, which includes most influence from tool geomety parameters. It was found that helix angle attenuates the rigidity of the end mill.

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수학교육에서 질적(Qualitative) 연구 방법 (Qualitative Research Method in Mathematics Education)

  • 이중권
    • 한국수학교육학회지시리즈A:수학교육
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    • 제42권2호
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    • pp.111-119
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    • 2003
  • This research discussed a general concept on the qualitative research methods in mathematics education. It provided a classification of research methods in mathematics education. It also described research trends in mathematics education. It addressed how research design facilitates formulating a research problem, selecting a research design, choosing who and what to study, deciding how to approach Participants, selecting means to collect data choosing how to analyzing data, and interpreting data and applying the analysis. This study addressed the issues involved in choosing relevant populations and in selecting and sampling qualitative data. It described how populations are conceptualized and distinguished between probability sampling and criterion based selection. It discussed not only data arrangement such as, cross-sectional and categorical indexing, non-cross- sectional data organization, but also diagram flow chart matrix, cognitive map, family tree to facilitate analyzing data.

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위상최적설계 결과를 이용한 CAD 인터페이스 (CAD Interface using Topology Optimization)

  • 김성훈;민승재;이상헌
    • 한국CDE학회논문집
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    • 제14권4호
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    • pp.281-289
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    • 2009
  • Topology optimization has been widely used for the optimal structure design for weight reduction and high performance. Since the result of three-dimensional topology optimization is represented by the discrete material distribution in finite elements, it is hard to interpret from a design point of view. In this paper, the method for interpreting three-dimensional topology optimization resuIt into a series of cross-sectional curve representation is proposed and interfaced with the existing CAD system for the practical use. The concept of node density and virtual grid is introduced to transform element density values into grid density and material boundaries in each cross section are identified based on the element volume rate to satisfy the amount of material specified in the original design intent. Design exampIes show that three-dimensional topology result can be converted into a form of curve CAD model and the seamless interface with CAD software can be achieved.

야쿠트의 종교혼합 현상에 대한 고찰: '아르치 지에테'(Archie Jiete)의 건립을 중심으로 (Religious Syncretism in Yakutia: A Case of the Building 'Archie Jiete')

  • 김중순
    • 비교문화연구
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    • 제25권
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    • pp.131-158
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    • 2011
  • In the Sakha(Yakutia) Republic, culture and politics continue to be interwined. Shamanism recently has come out of hiding after Soviet repression, and into fashion. Images of the shaman are changing in villages, where traditional healers have maintained their practices in difficult conditions, and in cities, where a resurgence of spirit belief and healing has led to the revitalization of their nationalism. Shamans and folk healers manipulate their own images, and in turn are changed by the upheavals of politicized cultural revitalization. In this complex and interactive context, folklore about traditional shamans has become especially rich and accessible. I argue here that religion has become an idiom through which competing definitions of homeland and national pride are being shaped. Until September 2002, Yakutsk had never had a 'temple' devoted to the practice of traditional shamanic beliefs. Indeed the whole concept that a building 'Archie Jiete' could contain or represent the beliefs, values and rituals of the Sakha people was new, and highly controversial.

전문용어 조어 및 번역 방법론에 대한 시론 (Essay on Terminology Formation and Translation Methodology in Korean)

  • 이현주
    • 비교문화연구
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    • 제31권
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    • pp.331-370
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    • 2013
  • In this knowledge based society, the circulation of knowledge and information is more and more increasing. Terms, as denominations of every specialized concept, has grown in quantity and there are considerable amount of foreign terminology coming to settle down in Korean language. Since terminologies quickly generate and be extinguished, it is important to translate in appropriate way at the very first phase of terminology implementation. This article aims to elaborate the typology of korean terminology translation forms, and propose some guidelines for terminology formation and translation methodology. ISO terminology principle and other institutes' propositions for term formation as well as translational theories constitute two basic columns of the guidelines.

라티노성(Latinidad) 논의의 사례와 의미 - 라틴 음악을 중심으로 (Rethinking Latinidad in Latin Music)

  • 이은아
    • 비교문화연구
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    • 제23권
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    • pp.295-319
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    • 2011
  • This study examines how Latinidad can be reclaimed as a site for exploring affinities of Latinos in Latin music industry, especially from the 90s. By looking at sites where Latinidad is constituted, such as the case of Jennifer $L{\acute{o}}pez$ becoming Selena, it intends to suggest that the concept can be deployed as a political bridge to connect latinos. And by examining Cuban-American artists' self identification in Latin Grammy Awards, it reveals that the latin music business definitions of Latinidad is coded differently for them as 'Caribbean' to erase a natural resonance of Cuba. In addition, by dealing with Shakira's somewhat contradictory representation of Colombianidad, the study argues that Latinidad serves as a social construct and newly emerges as a convenient interstitial place between the Latin American and the US Latino. Shakira's case serves to show how the transnational trends of latin music contribute to create a simultaneous sense of Latinidad and Colombianidad. Focusing on the commercial significance of understanding of what latino is or should be, this paper aims to interrogate current understandings of Latinidad in the realm of latin music and popular culture.

"Daffodil Gap": Reading Jamaica Kincaid's Lucy as Intertextual Interrogation of the Postcolonial Condition

  • Cho, Sungran
    • 비교문화연구
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    • 제21권
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    • pp.289-306
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    • 2010
  • In Jamaica Kincaid's novel Lucy, the narrator grows up with the burden of colonial legacies embedded with Englands' imperial disciplinary projects, its language, educational institutions, discourses. Colonial education interpellates the narrator into a colonial subject through its multiple ideological discourses and systems. Teaching the literature of England is the most insidious form of the Empire's disciplinary colonial projects, more powerful than military enforcement: Its mode of operation is creating phantasy and instigating and planting desire for such phantasy. As Homi Bhabha aptly theorizes as colonial mimicry and ambivalence, the narrator as colonial subject grows up split and confused as an ambivalent subject, simultaneously mimicking and desiring for the phantasized England as real, while resisting and criticizing such up-bringing and mimetic desire. This paper explores Kincaid's rhetorical strategy of employing Wordsworth's poem, "I Wandered as a Lonely Cloud," especially her use of the flower "daffodil." Employing the concept of "daffodil gap" suggested by postcolonial critics, this paper closely examines two episodes involving the flower daffodil in the novel, one in a colonial classroom and the other in a garden in a new world and suggests that Kincaid accomplishes intertextual critique of colonial education and imperial projects.