• 제목/요약/키워드: Approach theory

검색결과 3,607건 처리시간 0.032초

Hygrothermal analysis of laminated composites using C0 FE model based on higher order zigzag theory

  • Singh, S.K.;Chakrabarti, A.
    • Steel and Composite Structures
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    • 제23권1호
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    • pp.41-51
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    • 2017
  • A $C^0$ FE model developed based on an efficient higher order zigzag theory is used for hygrothermal analysis of laminated composite plates. The $C^0$ FE model satisfies the inter-laminar shear stress continuity at the interfaces and zero transverse shear stress conditions at plate top and bottom. In this model the first derivatives of transverse displacement have been treated as independent variables to circumvent the problem of $C^1$ continuity associated with the above plate theory. In the present theory the above mentioned $C^0$ continuity of the present element is compensated in the stiffness matrix formulation by using penalty parameter approach. In order to avoid stress oscillations observed in the displacement based finite element, the stress field derived from temperature/moisture fields (initial strains) must be consistent with total strain field. Special steps are introduced by field consistent approach (e.g., sampling at gauss points) to compensate this problem. A nine noded $C^0$ continuous isoparametric element is used in the proposed FE model. Comparison of present numerical results with other existing solutions shows that the proposed FE model is efficient, accurate and free of locking.

정보기술 비사용의 결정요인과 동태적 성격의 규명: 근거이론방법론에 의한 질적 연구 (Identifying the Determinants and the Dynamic Characteristics of ICT Non-Use: A Qualitative Study by Grounded Theory Methodolgy)

  • 이웅규
    • 한국정보시스템학회지:정보시스템연구
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    • 제27권1호
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    • pp.1-20
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    • 2018
  • Purpose The purpose of this study is to identify the determinants of non-use and the dynamic nature of non-use by the qualitative research methodology, grounded theory methodology, as part of identifying the nature of non-use. Design/methodology/approach We applied the grounded theory methodology to a total of 23 college students, including non-users who are not currently using them, users with low intention to use them, and users with high intention to use. We extracted the codes related to the use and proposed the non-use dynamics conversion process based on the coding results. Findings First, the use of information technology can also promote the frequency of use, but can also lead to the use of negative attitudes which would fall in the state of non-use. Second, the user may have both positive and negative attitudes toward the current information technology. Third, if usage is dominated by habits, it is not so easy to change persistent use into an unused state. Fourth, factors that determine the use of specific information technology can be a factor in determining nonuse. This study has contributed to understand the essence of non - use as well as the nature of use, overcoming limitations of quantitative research approach and confirming possibility of grounded theory method in information system research.

라마노바의 의상디자인 이론과 접근 방식 (The Principles of Clothing Design and the Way of Design Approach in Lamanova)

  • 이금희
    • 복식문화연구
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    • 제14권1호
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    • pp.108-127
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    • 2006
  • The purpose of this study is to examine the principles of clothing design and the way of design approach in Lamanova. She caused a revolution in the art of dress and created the foundation for costume design theory. She Addressed Art in everyday life to self-taught dressmakers. The distinguishing feature of the design is simplicity and functionality. In an article "The Russian Style", Lamanova raised the question of the new Soviet costume and traditional costume. In "On Contemporary Costume" she classified the new forms of clothes into everyday and holiday attire, showed the principles of costume, and analyzed in detail the necessity of constructing a costume to suit the individual figure. In "On the Rationality of Costume", she found a basis theory for clothing design which is for whom, from what, and for what purpose. Lamanova's theory was made public in full in 1928 and was presented at the exhibition of Handmade Textiles and Embroidery in Women's Contemporary Costume. The main contents are the costume's purpose, it's material, the figure of its wearer, and its form. She argued that the new costume could be in line with the new life and her theory could be the creed of clothing designers. The principles of Lamanova's theory can still be applied today, not only in Russian traditional and contemporary costume, but in contemporary world fashion.

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A Simple but Efficient Scheme for Reliable Connectivity and High Performance in Ad-hoc Wireless Networks

  • Tak, Sung-Woo
    • Journal of information and communication convergence engineering
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    • 제10권2호
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    • pp.141-148
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    • 2012
  • This paper presents a simple but efficient scheme incorporating a reputation-based approach and a cross-layer approach, called the SIM scheme, for maintaining reliable connectivity and high performance in ad-hoc wireless networks. The SIM scheme incorporates the following two things: an ad-hoc routing scheme with a reputation-based approach exploiting the game theory concept based on an evolutionarily stable strategy, and a cross-layer approach between the network layer and the transport layer employing a reputation-based approach.

家族硏究에 있어서 라이프 코오스(Life Course) 접근에 관한 고찰 (A Study on Life Course Approach in Family Studies)

  • 이인수
    • 가정과삶의질연구
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    • 제9권1호통권17호
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    • pp.1-11
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    • 1991
  • This paper reviews the literature on life course as a perspective in family studies. Life course approach on family studies have been emerged since 1960. This approach, which is challenging accepted knowledge and theory, partly reflects a shift in analytic perspective from structural models to a more behavioral thrust that views as a actor in structured situations, Life course approach is a theoretical orientation for our understanding of the linkage between individual and family development in context of changing historical context. Life course approach contributes time, process, and context to receiving in sociological perspectives on family and kinship.

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자동차 타이어의 Air-Pumping소음 예측을 위한 수치적 기법 (Numerical Method for Prediction of Air-pumping Noise by Car Tyre)

  • 김성태;정원태;정철웅;이수갑
    • 한국소음진동공학회논문집
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    • 제15권7호
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    • pp.788-798
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    • 2005
  • The monopole theory has long been used to model air-pumped effect from the elastic cavities in car tire. This approach models the change of an air as a Piston moving backward and forward on a spring and equates local air movements exactly with the volume changes of the system. Thus, the monopole theory has a restricted domain of applicability due to the usual assumption of a small amplitude acoustic wave equation and acoustic monopole theory This paper describes an approach to predict the air-pumping noise of a car tyre with CFD/Kirchhoff integral method. The tyre groove is simply modeled as piston-cavity-sliding door geometry and with the aid of CFD technique flow properties in the groove of rolling car tyre are acquired.'rhese unsteady flow data are used as a air-pumping source in the next CFD calculation of full tyre-road geometry. Acoustic far field is predicted from Kirchhoff integral method by using unsteady flow data in space and time which is provided by the CFD calculation of full tyre-road domain. This approach can cover the non-linearity of acoustic monopole theory with the aid of Non-linear governing equation in CFD calculation. The method proposed in this paper is applied to the prediction of air-pumping noise of simply modeled car tyre and through the predicted results, the influence of nonlinear effect on air-pumping noise propagation is investigated.

Heuristic Physical Theory of Diffraction for Impedance Polygon

  • Lee, Keunhwa;Park, Sanghyun;Kim, Kookhyun;Seong, Woojae
    • International Journal of Ocean System Engineering
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    • 제3권1호
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    • pp.22-32
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    • 2013
  • A heuristic physical theory of diffraction (PTD) for an acoustic impedance wedge is proposed. This method is based on Ufimtsev's three-dimensional PTD, which is derived for an acoustic soft or hard wedge. We modify the original PTD according to the process of physical optics (or the Kirchhoff approximation) to obtain a 3D heuristic diffraction model for an impedance wedge. In principle, our result is equivalent to Luebbers' model presented in electromagnetism. Moreover, our approach provides a useful insight into the theoretical basis of the existing heuristic diffraction methods. The derived heuristic PTD is applied to an arbitrary impedance polygon, and a simple PTD formula is derived as a supplement to the physical optics formula.

A systematic approach for the development of porous concrete based on axiomatic design theory

  • Tran, X.H.;Tawie, R.;Lee, H.K.
    • Computers and Concrete
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    • 제6권6호
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    • pp.491-503
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    • 2009
  • This paper presents a design framework developed using axiomatic design (AD) theory that can be applied in the design process of porous concrete. The main contribution of this paper is the definition of an AD framework based on the needs and functional requirements of porous concrete. The framework shows how AD theory can be used to provide guidelines for proportioning and manufacturing porous concrete. The advantage of the AD approach is that it systemizes the way to decouple design parameters and makes designers to think rationally between what we want to achieve and how we propose to satisfy the functional requirements of porous concrete. In this paper, test results of laboratory-size porous concrete specimens under compression were analyzed to evaluate the performance of the porous concrete based on the desired functional requirements.

The effect of magnetic field on a thermoelastic fiber-reinforced material under GN-III theory

  • Alzahrani, Faris S.;Abbas, Ibrahim A.
    • Steel and Composite Structures
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    • 제22권2호
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    • pp.369-386
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    • 2016
  • In this work, the two-dimensional generalized magneto-thermoelastic problem of a fiber-reinforced anisotropic material is investigated under Green and Naghdi theory of type III. The solution will be obtained for a certain model when the half space subjected to ramp-type heating and traction free surface. Laplace and exponential Fourier transform techniques are used to obtain the analytical solutions in the transformed domain by the eigenvalue approach. The inverses of Fourier transforms are obtained analytically. The results have been verified numerically and are represented graphically. Comparisons are made with the results predicted by the presence and absence of reinforcement and magnetic field.

카오스개념과 새로운 디자인사고에 관한 고찰 (A Study on the Concept of Chaos and New Design Thinking)

  • 김주미
    • 한국실내디자인학회논문집
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    • 제6호
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    • pp.28-37
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    • 1995
  • As we approach the end of the twentieth century, it seems we need a new way to express the thoughts, needs, and values that are undergoing a drastic change and a new strategy to create diverse cultural forms that would reflect and incorporate such changes. In this study, I am introducing the chaos theory as a new way of thinking that would help counterbalancing the deter-ministic world-view and forging a harmonious unity of man and his environment. As a creative principle, the theory seems to offer an unlimited number of structural possibilities for art and design. In fine, this study discuss-es the reductive nature of modernist approach and offer instead the chaos theory that is more probabilistic and capable of greater diversity.

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