• Title/Summary/Keyword: Models and Theories

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Van Fraassen on Empirical Equivalence Argument and Interpretations of Space-time (반 프라쎈의 경험동등성 논변과 시공간에 대한 해석)

  • Yang, Kyuong-Eun
    • Korean Journal of Logic
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    • v.15 no.1
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    • pp.85-107
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    • 2012
  • This essay criticizes Van Fraassen's argument for empirical equivalence among competing theories, which is based on his interpretation of Newtonian space-time. I argue that his misleading interpretation of the ontology of absolute space-time results in his ineffective attacks against a residual structure of space-time, absolute velocity. Van Fraassen's argument basically misleads us into empirical equivalence in that his literal reading of Newtonian space-time disregards a variety of aspects of its model.

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Comparative Evaluation of Dam-Break Models (댐파괴 모형의 비교평가)

  • 이창훈;이길성
    • Water for future
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    • v.22 no.3
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    • pp.323-330
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    • 1989
  • Three representative dam-break models, HEC-1, DAMBRK, and SMPDBK were analyzed respectively in theri theories and then applied to the failure of Teton Dam for which some observed data exist. From the results of this study, it can be concluded that: (1) HEC-1, which uses the hydrologic routing method, produces stable solutions for almost all the cases that were tested in this study; (2) DAMBRK, which uses the dynamic routing method, is most accurate among the three models; (3) SMPDBK, which uses the generalized dynamic routing relationships, is most economical and easily applicable.

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Fundamentals of Particle Fouling in Membrane Processes

  • Bhattacharjee Subir;Hong Seungkwan
    • Korean Membrane Journal
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    • v.7 no.1
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    • pp.1-18
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    • 2005
  • The permeate flux decline due to membrane fouling can be addressed using a variety of theoretical stand-points. Judicious selection of an appropriate theory is a key toward successful prediction of the permeate flux. The essential criterion f3r such a decision appears to be a detailed characterization of the feed solution and membrane properties. Modem theories are capable of accurately predicting several properties of colloidal systems that are important in membrane separation processes from fundamental information pertaining to the particle size, charge, and solution ionic strength. Based on such information, it is relatively straight-forward to determine the properties of the concentrated colloidal dispersion in a polarized layer or the cake layer properties. Incorporation of such information in the framework of the standard theories of membrane filtration, namely, the convective diffusion equation coupled with an appropriate permeate transport model, can lead to reasonably accurate prediction of the permeate flux due to colloidal fouling. The schematic of the essential approach has been delineated in Figure 5. The modern approaches based on appropriate cell models appear to predict the permeate flux behavior in crossflow membrane filtration processes quite accurately without invoking novel theoretical descriptions of particle back transport mechanisms or depending on adjust-able parameters. Such agreements have been observed for a wide range of particle size ranging from small proteins like BSA (diameter ${\~}$6 nm) to latex suspensions (diameter ${\~}1\;{\mu}m$). There we, however, several areas that need further exploration. Some of these include: 1) A clear mechanistic description of the cake formation mechanisms that clearly identifies the disorder to order transition point in different colloidal systems. 2) Determining the structure of a cake layer based on the interparticle and hydrodynamic interactions instead of assuming a fixed geometrical structure on the basis of cell models. 3) Performing well controlled experiments where the cake deposition mechanism can be observed for small colloidal particles (< $1\;{\mu}m$). 4) A clear mechanistic description of the critical operating conditions (for instance, critical pressure) which can minimize the propensity of colloidal membrane fluting. 5) Developing theoretical approaches to account for polydisperse systems that can render the models capable of handing realistic feed solutions typically encountered in diverse applications of membrane filtration.

Theories and Practices of Early Childhood Teachers: Bottom-up Perspectives (유아 교사의 이론과 실천에 관한 고찰: bottom-up 관점을 중심으로)

  • Kim, Miai
    • Journal of Digital Convergence
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    • v.15 no.6
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    • pp.107-119
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    • 2017
  • This article explores early childhood teachers' practices from bottom-up perspectives on the relationship between theory and practice. Results of the review of literature are as follows: 1) From top-down perspectives early childhood teachers' practices and their classroom behaviors have been traditionally defined within the framework of theories of child development, the notion of developmentally appropriate practice, and designed program models; 2) From bottom-up perspectives researchers have a focus on how teachers' practices lead theories and how they construct the act of teaching through reflective thinking; 3) empirical research on preservice and inservice teachers demonstrates that preservice teachers develop their own theories of teaching from their previously held assumptions, gained knowledge from preparation programs, and their individual experiences. It also shows that inservice teachers construct teaching through their implicit knowledge and the use of strategies to negotiate problems. Implications for future studies on teachers's practices are discussed.

Application of Health Behavior Theories to Breast Cancer Screening among Asian Women

  • Ahmadian, Maryam;Samah, Asnarulkhadi Abu
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.7
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    • pp.4005-4013
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    • 2013
  • Background: Although breast cancer is a major public health worry among Asian women, adherence to screening for the disease remains an obstacle to its prevention. A variety of psycho-social and cultural factors predispose women to delay or avoidance of screening for breast cancer symptoms at the early stages when cure is most likely to be successful. Yet few interventions implemented to date to address this condition in this region have drawn on health behavior theory. Materials and Methods: This paper reviews the existing literature on several cognitive theories and models associated with breast cancer screening, with an emphasis on the work that has been done in relation to Asian women. To conduct this review, a number of electronic databases were searched with context-appropriate inclusion criteria. Results: Little empirical work was found that specifically addressed the applicability of health theories in promoting adherence to the current breast cancer prevention programs Among Asian women. However, a few studies were found that addressed individual cognitive factors that are likely to encourage women's motivation to protect themselves against breast cancer in this region of the world. The findings suggest that multi-level, socio-cultural interventions that focus on cognitive factors have much promise with this issue. Conclusions: Interventions are needed that effectively and efficiently target the personal motivation of at-risk Asian women to seek out and engage in breast cancer prevention. Concerning implications, personal motivation to seek out and engage in individual preventive actions for breast cancer prevention among Asian women is a timely, high priority target with practical implications for community development and health promotion. Further studies using qualitative, anthropologic approaches shaped for implementation in multi-ethnic Asian settings are needed to inform and guide these interventions.

On the effect of the micromechanical models on the free vibration of rectangular FGM plate resting on elastic foundation

  • Mahmoudi, Abdelkader;Benyoucef, Samir;Tounsi, Abdelouahed;Benachour, Abdelkader;Bedia, El Abbas Adda
    • Earthquakes and Structures
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    • v.14 no.2
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    • pp.117-128
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    • 2018
  • In this research work, free vibrations of simply supported functionally graded plate resting on a Winkler-Pasternak elastic foundation are investigated by a new shear deformation theory. The influence of alternative micromechanical models on the macroscopic behavior of a functionally graded plate based on shear-deformation plate theories is examined. Several micromechanical models are tested to obtain the effective material properties of a two-phase particle composite as a function of the volume fraction of particles which continuously varies through the thickness of a functionally graded plate. Present theory exactly satisfies stress boundary conditions on the top and the bottom of the plate. The energy functional of the system is obtained using Hamilton's principle. The closed form solutions are obtained by using Navier technique, and then fundamental frequencies are found by solving the results of eigenvalue problems. Finally, the numerical results are provided to reveal the effect of explicit micromechanical models on natural fundamental frequencies.

Comparison of Different Numerical Models of RC Elements for Predicting the Seismic Performance of Structures

  • Zendaoui, Abdelhakim;Kadid, A.;Yahiaoui, D.
    • International Journal of Concrete Structures and Materials
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    • v.10 no.4
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    • pp.461-478
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    • 2016
  • This paper aims to provide guidelines for the numerical modeling of reinforced concrete (RC) frame elements in order to assess the seismic performance of structures. Several types of numerical models RC frame elements are available in nonlinear structural analysis packages. Since these numerical models are formulated based on different assumption and theories, the models accuracy, computing time, and applicability vary, which poses a great difficulty to practicing engineering and limits their confidence in the analysis resultants. In this study, the applicability of four representative numerical models of RC frame elements is evaluated through comparison with experimental results of four-storey bare frame available from European Laboratory for Structural Assessment. The accuracy of a numerical model is evaluated according to the top displacement, interstorey drift, Maximum storey shear, damage pattern and energy dissipation capacity of the frame structure. The results obtained allow a better understanding of the characteristics and potentialities of all procedures, helping the user to choose the best approach to perform nonlinear analysis.

Exploring Practices of Interpretation and Communication in Art Museums (미술관의 해석과 소통의 모색)

  • Kim, Elm-Yeong
    • The Journal of Art Theory & Practice
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    • no.2
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    • pp.147-168
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    • 2004
  • This study examined the role of interpretation with various practices in art museums to seek a new meaning and a concept of art museum today. The exploration of interpretation would he a starting point to discuss about on art museums with professionals in each art-related field. While museums recognize the concept of interpretation and the scope of the functions in different levels, the study focused on the practices of collecting and exhibiting that will entrust the museum new realms of activities toward the audience. In particular, its emphases are set force on the information on the collections via the museum's web sites, interpretation policies, and theories and methodologies in exhibition development. Art museum websites well reflect how museums utilize the new medium to enhance the understanding of art works by providing in-depth art historical information, comprehensive contexts, and subject/concept based search methods. In recent decades, these have enacted changes to expand dimensions of interpretive functions in most museums, particularly in the United States and others. In an administrative perspective, Tate Gallery Interpretation Policy became an good example how an art museum put its interpretation philosophy as the basis of interpreting collection and public programs. Tate established functions of intrepretation and education not only within a task-based team but also as an intrer-divisional coorperation to provide an interpretation scheme of information provisions such as guide brochure, audio tour, multimedia content, and library. New environment and trends of museum exhibition, and its development processes stem from communication theories, object interpretation philosophy, display strategies, and various evaluation techniques through audiences, with the communication theories of Shannon and Weaver, Berlo's SMCR(Source-Message-Channel-Receiver) models were perceived as to understand the mechanism to communicate museum exhibits to visitors Suzan vogel's insight into object display strategy helped to conceive the mechanism of object recontextualization. She emphasized that the museum's practice to construe opinions and impressions through object display should be discreet and critical, therefore, the professionals to plan the exhibition should reveal the intention and their practices. For a prevailing new methodology from the field, the interpretive exhibition development processes are articulated as the front-end, formative, and summative evaluation, futhermore the team process in industrial product management models was adapted. These have turned out to be more interactive with visitors and effective to communicate the exhibition concepts and messages, hence resulting in enriched museum experiences. Finally the study concluded that understanding the aspects of interpretation should help art museums to set a framework for current practices to expand its public dimension. It can provide curators with a critical view to website planning and its content. And obviously, the interpretive exhibition development methodology will lead museum exhibition developers to be skilled in its current approaches to thematic exhibition concerning diverse subjects and topics.

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Theoretical Framework for the Research on Family Business (가족기업연구를 위한 이론적 틀의 탐색)

  • 홍성희
    • Journal of the Korean Home Economics Association
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    • v.38 no.9
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    • pp.19-32
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    • 2000
  • The purpose of this study was to discuss previous studies and theories on family business. This study were to examine the dominant trends in the precious research, and to introduce several conceptual frameworks and models, such as family business theory, family resource management theory, theory of household adjustment and adaptation, and family business viability model. This study will be helpful in understanding of the relationship between family and business, and the work-family interface, and in developing policies and programs that assist family business and enhance the well-being for family members who are involved in family business.

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Design Optimization of Structure-born Noise of Automobile (자동차 소음/진동의 최적 설계)

  • 왕세명;최경국;하리쿨카니
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.10a
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    • pp.104-109
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    • 1996
  • Continuum element sensitivity analysis (CONTESA) and system optimization (SYSOPT) for Noise, Vibration, and Harshness (NVH) have been developed and applied to automobile structures for sizing, topology, and configuration design using Mindlin plate and Timoshenko beam theories. The topology optimization has been developed using the density approach, sequential linear programming, and the adjoint variable method. CONTESA has been tested using various vehicle models. Optimized vehicles using CONTESA and SYSOPT are manufactured to validate the simulation-based design methodology.

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