• 산업경영시스템학회지
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• 제8권11호
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• pp.57-68
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• 1985

Theories of capital have historically been amongst the most fertile sources of economic controversy. Many aspects of the modern debate, if not the techniques employed in its exposition, would have been as familiar to Marx, Ricardo, Bohm-Bawerk or Wicksell as to any present-day Cambridge economist. That conotroversies should arise in the course of theorizing cm the concept of capital and the function of profit is not surprising: that these debates have been so vigorous and virluent cannot be divorced from the general ideological and specific implications associated with the theories. In the context of a textbook on the theories of economic growth, the central question associated with capital that must he faced is whether the existence in the real world of heterogeneous capital goods inevitably invalidate; the conclusions of simple theories of "parables" which incorporate no more than a conception of a single, malleable, capital good. All the Cambridge writers have, to a greater or lesser extent, been concerned to deny that any unit can be found in which heterogeneous capital goods can be aggregated so as to simultaneously satisfy the pair of neoclassical requirements described above. Some of them have been more prepared than others to countenance such a possibility or, for practical purposes, to use some concept of aggregate capital in their models, but they are all deeply suspicious of attempts to use aggregate production function, incorporating aggregate "capital", so as to explain the flow of output, relative factor prices and the distribution of income.tribution of income.

• 한국초등과학교육학회지:초등과학교육
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• 제17권1호
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• pp.23-32
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• 1998

A good example of the persistence of naive theories about change in seasons is well knowned: A filmmaker carried a camera into the crowd of gowned graduates at the 1987 commencement of Harvard University and asked a simple question, that is, "Why is it hotter in summer than in winter?" to twenty five students chosen at random. All of the answers except two were that the Earth is closer to the Sun in summer, so it is hotter in summer, but the Earth is farther from the Sun in winter, so it is cooler in winter. Until now, naive theories about the cause in seasons have been extensively studied. However, few studies to overcome these naive theories were reported. Author takes two steps: first, a new model on the cause in seasons is developed. Second, preservice students concepts' change on the cause in seasons through the new model is observed. The author concludes that the new model have a good effect on the preservice students concepts' change on the cause in seasons.

• Journal of Preventive Medicine and Public Health
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• 제26권4호
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• pp.508-533
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• 1993

지금까지 우리나라의 국민들의 예방행태와 질병행태, 그리고 환자역할에 대하여 기존에 발표된 자료를 중심으로 재해석을 기하여 보았다. 물론 이 발표에서 사용된 자료들이 정확하며 타당한 자료인가에 대해서는 반드시 그렇다라고 답변할 수는 없다. 다만 우리나라에서의 건강관련행태를 설명하기 위해서는 자료의 한계라는 현실을 감안하지 않을 수 없다는 사실을 이해해주기 바란다. 우리나라국민들의 건강행태는 과거에 비해 상당히 변화하고 있으나 계층간의 행태의 차이, 변화의 원인 등에 대해서는 아직 연구가 미흡하다. 지금까지 이루어진 행태연구들이 정합적인 모형을 사용하고 있다고 보기 어려운 것이 그 원인의 하나 일 것이다. 새로이 개발된 모형들을 적용하기 위한 노력이 필요하며, 사용되는 변수의 타당성에 대한 연구도 필요하다. 행태와 관련된 연구에서 사용되는 변수들이 사회문화의 산물이라는 사실을 생각하면 우리나름대로의 변수정의가 있어야 한다는 것은 지극히 당연하다 하겠다. 끝으로 행태를 연구함에 있어 인간의 의식은 사회구조의 산물이라는 사실을 명심할 필요가 있다. 루카치는 자본주의 사회에서는 노동자의 계급의식 역시 자본주의 구조의 산물일 수 있다 하였다. 이런 의미에서 지식, 태도, 행태 등에 대한 연구는 사회구조의 총체성에 대한 인식을 요구한다. 만일 그렇지 않은 경우에는 행태연구를 통한 결과가 희생자비난의 논리로 악순환할 가능성이 높기 때문이다.

• 한국초등과학교육학회지:초등과학교육
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• 제28권4호
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• pp.450-466
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• 2009

The purpose of this study was to explore preservice elementary teachers' perceptions on models used in science and science education. Participants were sixty-one undergraduate students who were enrolled in a science education course offered at a university of education located in a mid-sized city, Korea. Data were obtained from the participants at the beginning of the course when they provided their answers to a questionnaire about models. The analysis revealed that a large number of the preservice teachers perceived models as representative of physical realities. By contrast, a relatively small number of them viewed models as representations of ideas or things like theories or hypotheses. Lots of the participants were apt to define a model from the perspective of its functions and considered the purposes of models communication, teaching, and understanding as well as visualization, simplification, and clarification. Most of the preservice teachers believed that there could be multiple models for a single target, and all of them answered that models could be changed in science. It was therefore concluded that the preservice teachers perceived properly the multiplicity and variability of models. Nevertheless, they could not elaborate how a model is used and evaluated in the process of scientific inquiry, and just a few of them mentioned the detailed nature of models. The preservice teachers possessed teacher-centered views of using models in the science classroom, and a small number of them remarked that they were going to use models for students to develop their own models and perform scientific inquiry.

• International Journal of Concrete Structures and Materials
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• 제4권1호
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• pp.37-43
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• 2010

Theoretical models based on modern interpretations of the morphology and interactions of cement hydration products are developed for prediction of the mechanical properties of hydrated cement paste (hcp). The models are based on the emerging nanostructural vision of calcium silicate hydrate (C-S-H) morphology, and account for the intermolecular interactions between nano-scale calcium C-S-H particles. The models also incorporate the effects of capillary porosity and microcracking within hydrated cement paste. The intrinsic modulus of elasticity and tensile strength of hydrated cement paste are determined based on intermolecular interactions between C-S-H nano-particles. Modeling of fracture toughness indicates that frictional pull-out of the micro-scale calcium hydroxide (CH) platelets makes major contributions to the fracture energy of hcp. A tensile strength model was developed for hcp based on the linear elastic fracture mechanics theories. The predicted theoretical models are in reasonable agreements with empirical models developed based on the experimental performance of hcp.

• Archives of Plastic Surgery
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• 제41권3호
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• pp.218-224
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• 2014

Plastic surgery training worldwide has seen a thorough restructuring over the past decade, with the introduction of formal training curricula and work-based assessment tools. Part of this process has been the introduction of revalidation and a greater use of simulation in training delivery. Simulation is an increasingly important tool for educators because it provides a way to reduce risks to both trainees and patients, whilst facilitating improved technical proficiency. Current microsurgery training interventions are often predicated on theories of skill acquisition and development that follow a 'practice makes perfect' model. Given the changing landscape of surgical training and advances in educational theories related to skill development, research is needed to assess the potential benefits of alternative models, particularly cross-training, a model now widely used in non-medical areas with significant benefits. Furthermore, with the proliferation of microsurgery training interventions and therefore diversity in length, cost, content and models used, appropriate standardisation will be an important factor to ensure that courses deliver consistent and effective training that achieves appropriate levels of competency. Key research requirements should be gathered and used in directing further research in these areas to achieve on-going improvement of microsurgery training.

• International Journal of Quality Innovation
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• 제3권2호
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• pp.174-182
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• 2002

System identification and controller formulation are essential in dynamic process control. In system identification, data for system identification are obtained, and then they are analyzed so that the system model of the process is built, identified, and diagnosed. In controller formulation, the control equation is derived based on the result of the system identification. There has been much theoretical research on system identification and controller formulation. These theories are very useful when they are appropriately applied. To our regret, however, these theories are not always effectively applied in practice because the engineers and the operators who manage the process often do not have the necessary understanding of required time series analysis methods. On the other hand, because of widespread use of statistical packages, system identification such as estimating ARMA models can be done with little understanding of time series analysis methods. Therefore, it might be said that the most theoretically difficult part in practice is the controller formulation. In this paper, lists of control equations are proposed as a useful tool for practitioners to use. The tool supports bridging the gap between theory and practice in dynamic process control. Also, for some models, the generalized control equations are obtained.

• Computers and Concrete
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• 제27권3호
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• pp.253-268
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• 2021

The present paper treats the free vibration problem of the masonry wall strengthened with thin composite plate by viscoelastic adhesive layer. For this goal two steps are considered in the analytical solution. In the first one, an efficient homogenisation procedure is given to provide the anisotropic properties of the masonry wall. The second one is dedicated to purpose simplified mathematical models related to both in-plane and out-of-plane vibration problems. In these models, the higher order shear theories (HSDT's) are employed for a more rigours description of the shear deformation trough the masonry wall and the composite sheet. Ritz's method is deployed as solution strategy in order to get the natural frequencies and their corresponding loss factors. The obtained results are validated with the finite element method (FEM) and then, a parametric study is undertaken for different kinds of masonry walls strengthened with composite sheets.

• 한국문헌정보학회지
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• 제41권1호
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• pp.55-84
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• 2007

본 연구는 학교도서관 정책을 평가하기 위하여 정책학에서 제시한 기준을 토대로 평가모형을 개발하고 이 평가모형에 '학교도서관 활성화 종합방안'을 적용하여 학교도서관 정책에 대한 평가를 진행하였다. 학교도서관 정책을 평가하기 위한 기준은 여러 학자가 제시한 이론 중에서 교육정책과 학교도서관 정책에 관한 선행 평가모형을 근거로 하였다. 선정된 평가기준은 평가자에게 배부한 설문지와 전화인터뷰를 통하석 검증하였다. 학교도서관 정책에 대한 평가결과는 대체로 긍정적이었나 일부 정책개선 노력이 필요하다는 내용이 제기되었다.

• 컴퓨터교육학회논문지
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• 제11권2호
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• pp.13-22
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• 2008

본 연구는 학습자의 인지발달 단계를 고려한 중학교 정보 교과서의 내용 구성 방안에 관한 것으로서, 정보 과목의 목표와 학습자 활동을 고려하여 3 가지 학습내용 모델을 선정하였으며 각각에 대한 내용 구성 방안을 제안하였다. 이를 위하여 청소년에 대한 인지발달 이론들을 분석하여 학습자의 발달 특성을 이해하고, 관련된 교육학적 이론을 토대로 학습 유형에 적합한 교수 학습 방안을 도출하였다. 그런 다음, 정보 과목의 학습내용의 특징을 분석하여 개념학습중심, 탐구학습중심, 실습중심의 내용 구성 모델을 제시하고, 학습자의 발달단계를 고려한 교과서 내용구성 방안을 제안하였다. 내용 구성 방안에 대한 타당성 검증을 위하여 중학교의 정보 과목 담당 교사 30명을 대상으로 설문조사를 수행하였으며 긍정적인 결과를 얻었다.