• Title/Summary/Keyword: Potential theory

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Re-examining the Potential for Schema to Aid Students towards Developing EFL Reading Skills

  • Nairn, Anthony George;Im, Byung-Bin
    • English Language & Literature Teaching
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    • v.16 no.1
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    • pp.81-100
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    • 2009
  • The current study reported on the continuing relevance of the schema theory for reading as it relates to the field of teaching and SLA, whilst highlighting the inherent limitations affecting individual learners. A relevant study was conducted for this article focusing on the extent to which university teacher trainees of English Education are exposed to second language readings with an adherence towards utilizing prior knowledge and drawing upon schemata to support their comprehension. Results from quantitative and qualitative data measured and collected from two groups of university students respectively, indicated certain advantages to this strategy use in respect of increased understanding, familiarity, and comfort level in SL reading. However, those same results identified existing limitations associated with cultural bias, stereotyping and a tendency to focus on wrong information when activating said schemata. As such, the purpose of this study is to promote awareness of the schema theory as an effective strategy option whilst reinforcing a need to pay heed to the concerns associated with strict reliance upon such theory to aid reading skills. Further discussion of these issues and pedagogical implications has been provided along with both suggested considerations regarding teaching for EFL teachers and evaluators.

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Elastic-Plastic Implicit Finite Element Method Considering Planar Anisotropy for Complicated Sheet Metal Forming Processes (탄소성 내연적 유한요소법을 이용한 평면 이방성 박판의 성형공정해석)

  • Yun, Jeong-Hwan;Kim, Jong-Bong;Yang, Dong-Yeol;Jeong, Gwan-Su
    • Transactions of Materials Processing
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    • v.7 no.3
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    • pp.233-245
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    • 1998
  • A new approach has been proposed for the incremental analysis of the nonsteady state large deformation of planar anisotropic elastic-plastic sheet forming. A mathematical brief review of a constitutive law for the incremental deformation theory has been presented from flow theory using the minimum plastic work path for elastic-plastic material. Since the material embedded coordinate system(Lagrangian quantity) is used in the proposed theory the stress integration procedure is completely objective. A new return mapping algorithm has been also developed from the general midpoint rule so as to achieve numerically large strain increment by successive control of yield function residuals. Some numerical tests for the return mapping algorithm were performed using Barlat's six component anisotropic stress potential. Performance of the proposed algorithm was shown to be good and stable for a large strain increment, For planar anisotropic sheet forming updating algorithm of planar anisotropic axes has been newly proposed. In order to show the effectiveness and validity of the present formulation earing simulation for a cylindrical cup drawing and front fender stamping analysis are performed. From the results it has been shown that the present formulation can provide a good basis for analysis for analysis of elastic-plastic sheet metal forming processes.

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Spacecraft Attitude Determination Study using Predictive Filter (Predictive Filter를 이용한 인공위성 자세결정 연구)

  • Choi , Yoon-Hyuk;Bang, Hyo-Choong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.11
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    • pp.48-56
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    • 2005
  • Predictive filter theory proposed recently can be characterized by inherent advantages of estimating modelling error and overcoming the disadvantage of the Kalman filter theory. A one-step ahead error is minimized to produce optimized filter performance in the form of the predictive filter. The main advantage of this filter lies in the ability to estimate both state vector and system model error. In this paper, attitude estimation results based upon the predictive filter theory is addressed. Mathematical formulation for estimating bias signal is peformed by using the predictive filter theory, and attitude estimation based upon vector observation is presented. From the results of this study, the potential applicability of the predictive filter is highlighted.

A New Development in the Theory of Slender Ships (세장선 이론의 새로운 전개)

  • 김인철
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.27 no.1
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    • pp.83-90
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    • 1991
  • The method, which is introduced here, is an approximation derived by an application of the slender body theory, which has achieved a great success in the field of aeronautical engineering. However numerical results for wave resistance by this theory have been very disappointing. A slender body formulation for a ship in uniform forward motion si presented. It is based on the asymptotic expansion of the Kelvin source and the result is quite different from the existing slender ship theory developed by Vossers, Tuck and Maruo. It is equivalent to an approximation for the kernel function of the Neumann-Kelvin problem which assumes the linearized free surface condition but deals with the body boundary condition in its exact from. The velocity field and pressure distribution can be calculated simply by the differentiation of the two-dimensional velocity potential. A formula for the wave resistance of slender ships is also presented.

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Marguerre shell type secant matrices for the postbuckling analysis of thin, shallow composite shells

  • Arul Jayachandran, S.;Kalyanaraman, V.;Narayanan, R.
    • Structural Engineering and Mechanics
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    • v.18 no.1
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    • pp.41-58
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    • 2004
  • The postbuckling behaviour of thin shells has fascinated researchers because the theoretical prediction and their experimental verification are often different. In reality, shell panels possess small imperfections and these can cause large reduction in static buckling strength. This is more relevant in thin laminated composite shells. To study the postbuckling behaviour of thin, imperfect laminated composite shells using finite elements, explicit incremental or secant matrices have been presented in this paper. These incremental matrices which are derived using Marguerre's shallow shell theory can be used in combination with any thin plate/shell finite element (Classical Laminated Plate Theory - CLPT) and can be easily extended to the First Order Shear deformation Theory (FOST). The advantage of the present formulation is that it involves no numerical approximation in forming total potential energy of the shell during large deformations as opposed to earlier approximate formulations published in the literature. The initial imperfection in shells could be modeled by simply adjusting the ordinate of the shell forms. The present formulation is very easy to implement in any existing finite element codes. The secant matrices presented in this paper are shown to be very accurate in tracing the postbuckling behaviour of thin isotropic and laminated composite shells with general initial imperfections.

Game Theory based Dynamic Spectrum Allocation for Secondary Users in the Cell Edge of Cognitive Radio Networks

  • Jang, Sungjin;Kim, Jongbae;Byun, Jungwon;Shin, Yongtae
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.7
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    • pp.2231-2245
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    • 2014
  • Cognitive Radio (CR) has very promising potential to improve spectrum utilization by allowing unlicensed Secondary Users (SUs) to access the spectrum dynamically without disturbing licensed Primary Users (PUs). Mitigating interference is a fundamental problem in CR scenarios. This is particularly problematic for deploying CR in cellular networks, when users are located at the cell edge, as the inter-cell interference mitigation and frequency reuse are critical requirements for both PUs and SUs. Further cellular networks require higher cell edge performance, then SUs will meet more challenges than PUs. To solve the performance decrease for SUs at the cell edge, a novel Dynamic Spectrum Allocation (DSA) scheme based on Game Theory is proposed in this paper. Full frequency reuse can be realized as well as inter-cell interference mitigated according to SUs' sensing, measurement and interaction in this scheme. A joint power/channel allocation algorithm is proposed to improve both cell-edge user experience and network performance through distributed pricing calculation and exchange based on game theory. Analytical proof is presented and simulation results show that the proposed scheme achieves high efficiency of spectrum usage and improvement of cell edge SUs' performance.

Effective shared process and application of knowledge management (KM) in interior design service industry

  • Choi, Seung-Pok
    • International Journal of Contents
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    • v.6 no.3
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    • pp.65-70
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    • 2010
  • This paper addresses the importance of knowledge management (KM) and the relationship of that theory when applied to improving interior design organizational performance in four areas: people, processes, design products, and organizational performance. Included is the way knowledge theory manifests in three different professional settings: coaching and training, designing, and service settings. Knowledge management, although well established in interior design services, requires effort in coaching and training as motivation is a critical variable. Whereas, strategies for knowledge management vary from industry to industry given diversity in situational variables, knowledge in each professional setting can be significantly aided by capturing and storing empirical, tacit, and explicit information, providing real-time electronic storage and retrieval of information [5] and consistent with transformational theory, through opening communication channels across the full range of the organization, inspiring and motivating individuals, and aligning all members of the organization toward a common vision [8]. Professional settings discussed in this paper are:(a)an learning organization enumerated in KM; (b)designing factors for managing knowledge theory themes; and (c)service, effective, efficient, and innovative KM application that is relevant to the process of developing effective KM for interior design service organizations. Folded within each will be a discussion on KM's impacts on visions, strategies, costs, and organizational performance. It has reiterated the impact of KM on one level might lead to synergistic impacts on another. Thus, KM has the potential to produce several interconnected impacts on people, design products, processes, and organizations.

The Factors Influencing Information Technology Non-Acceptance: Approach by Grounded Theory (정보기술 비수용에 영향을 미치는 요인: 근거이론에 의한 접근)

  • Lee, Woong-Kyu;Park, Jin-Hoon
    • The Journal of Information Systems
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    • v.24 no.4
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    • pp.83-97
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    • 2015
  • Purpose: Traditionally, information technology acceptance have been considered one of the most important research issues. However non-acceptance, which was main objective of acceptance theories, have not been included in main research area by communities of information systems. This study is to identify the factors influencing non-acceptance of information technology and suggest a total research model for explaining the phenomena of non-acceptance. Design/methodology/approach: Grounded theory was adopted as a principal research method. which is an inductive technique of interpreting qualitative data about a social phenomenon to build theories about that phenomenon. Data were collected by depth interview and open question on potential non-adopters during 3 months. The collected data were coded by two main coding paradigm in ground theory, open coding and axis coding. Findings: Factors influencing non-acceptance, status quo, imitation, value evaluation, and concerning risk were extracted from open coding. These factors were integrated into system 1 thinking and system 2 thinking, which were from axis coding. More specifically, status quo and imitation are system 1 thinking which are more responsive and emotional thinking and value evaluation and concerning risk are system 2 thinking which are more rational and reasoning thinking.

Linear Response Theory for the Mechanical Energy Relaxation of Solid High Polymers at Low Temperature (抵溫에서의 固體 重合體의 力學的 에너지 緩和에 對한 線形反應 理論)

  • Eu, Byung Chan
    • Journal of the Korean Chemical Society
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    • v.20 no.5
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    • pp.340-350
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    • 1976
  • Linear response theory is proposed to be applied for theoretical description of the phenomena in mechanical spectroscopy of solid high polymers below glass transition temperatures. The energy dissipation by sample is given in terms of certain time correlation functions. It is shown that the result leads to the result by Kirkwood on the energy loss and relaxation of cross-linked polymers, if the Liouville operator is replaced by the diffusion equation operator of Kirkwood. An approximation method of calculating the correlation functions is considered in order to show a way to calculate relaxation times. Using the approximation method, we consider a double-well potential model for energy relaxation, in order to see a connection between the present theory and a model theory used in mechanical energy relaxation phenomena of solid polymers containing pendant cyclohexyl groups at low temperature.

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Introducing an Online Measurement System Using Item Response Theory and Computer Adaptive Testing Methods for Measuring the Physical Activity of Community-Dwelling Frail Older Adults

  • Choi, Bong-sam
    • Physical Therapy Korea
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    • v.26 no.3
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    • pp.106-114
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    • 2019
  • Background: It is difficult to assess whether community-dwelling frail older adults may remain pre-frail status or improve into a robust state without being directly checked by health care professionals. The health information perceived by older adults is considered to be one of best sources of potential concerns in older adult population. An online measurement system combined with item response theory (IRT) and computer adaptive testing (CAT) methods is likely to become a realistic approach to remotely monitor physical activity status of frail older adults. Objects: This article suggests an approach to provide a precise and efficient means of measuring physical activity levels of community-dwelling frail older adults. Methods: Article reviews were reviewed and summarized. Results: In comparison to the classical test theory (CTT), the IRT method is empirically aimed to focus on the psychometric properties of individual test items in lieu of the test as a whole. These properties allow creating a large item pool that can capture the broad range of physical activity levels. The CAT method administers test items by an algorithm that select items matched to the physical activity levels of the older adults. Conclusion: An online measurement system combined with these two methods would allow adequate physical activity measurement that may be useful to remotely monitor the activity level of community-dwelling frail older adults.