• Nuclear Engineering and Technology
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• 제53권3호
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• pp.851-859
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• 2021

Small PWR can be used for power generation and heating. Considering that small PWR has the characteristics of flexible operating conditions and complex operating environment, the controller designed based on single power level is difficult to achieve the ideal control of small PWR in the whole range of core power range. To solve this problem, a flexible switching controller based on fuzzy controller and LQG/LTR controller is designed. Firstly, a core fuzzy multi-model suitable for full power range is established. Then, T-S fuzzy rules are designed to realize the flexible switching between fuzzy controller and LQG/LTR controller. Finally, based on the core power feedback principle, the core flexible switching control system of small PWR is established and simulated. The results show that the flexible switching controller can effectively control the core power of small PWR and the control effect has the advantages of both fuzzy controller and LQG/LTR controller.

• 수산해양교육연구
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• 제20권2호
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• pp.184-200
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• 2008

The purpose of this paper is to develop instructional activity support model for capstone design in order for improving creative engineering education. To do this, having extracted the core idea of capstone design, and elicited core learning activity process, and grasped core supportive factors according to each core learning activity process that elicited, an improved instructional design model for capstone design was then developed through formative evaluation with respect to the draft of the instructional system development model for capstone design. As to major research methods, case analysis, requirements analysis through interview, and formative evaluation by experts were employed, and then research studies were undertaken. The formative evaluation by experts was carried out for two hours in 2007, and the experts participated in the evaluation consisted of total 6 persons: two specialists of capstone design contents, two professionals in field works, and two expert instructional designers in education engineering. Interview results had been reflected in this research when developing final instructional design model for capstone design. The core learning activity process of the final instructional design model for caption design, which developed in this research, comprises following stages: (1) Team building $\rightarrow$ (2) Integrated meeting between industry and academy $\rightarrow$ (3) Analysis of tasks $\rightarrow$ (4) Clarification of tasks $\rightarrow$(5) Seeking solutions for issues $\rightarrow$ (6) Eliciting priority of solutions $\rightarrow$ (7) Designing solutions and construction $\rightarrow$ (8) Exhibiting outcomes and presentation $\rightarrow$(9) Gaining comprehensive insights Also, in the core learning activity process, supportive factors that support implementation of each step were presented having been categorized into facilitator (teacher, and professionals in field works), learner and tool, etc.

• 융합보안논문지
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• 제14권6_1호
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• pp.3-12
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• 2014

본 연구는 우수 장교양성을 목적으로 시행중인 군사학과 학생들의 자질과 품성 함양을 위한 훈육교수의 역할과 훈육을 담당하는 교수의 핵심역량을 어떻게 어떤 항목으로 할 것인가와 이를 개발하기 위한 역량 모델을 제시하고자 하였다. 이 연구를 통하여 군사학과 교육운영체계의 전반적인 발전방안을 제시하는데 그 목적이 있다. 이와 같은 연구목적을 달성하기 위해 본 연구는 기존 훈육의 개념에 대한 선행연구와 이론을 기초로 발전방안을 제시하였다. 여기에 제시된 내용은 사관학교 위주의 선행연구를 기초로 하여 훈육요원에게 필요한 핵심 역량인 교수 평가 생활 지도 학급경영 역량을 일반적 운영절차에 따라 계획 준비 실시 성과분석단계로 구분하여 어떻게 진행하고 조치할 것인가에 대한 모델을 제시했다는데 의의가 있으며 여기서 제시한 연구결과는 일반대학 군사학과의 훈육담당 교수의 역할과 역량을 효율적으로 발휘하기 위한 모델을 제시하기 위해 연구되었다. 훈육에 관련된 모델은 사관학교에서 부분적으로 연구되었으나 본 연구는 민간대학 군사학과 학생들의 훈육을 담당하는 교수들의 역량을 효율적으로 극대화하기 위한 모델을 제시했다는데 그 의의가 있다. 그러나, 여기서 제시한 모델은 최근 군 교육기관에서 연구된 일부 내용들과 일반적인 훈육관련 선행연구들을 기초로 만들어진 모델이기 때문이 이것을 모든 대학이 그대로 적용하기에는 약간의 제한 사항들이 도출될 수 있다. 따라서 이 연구를 출발점으로 하여 민간대학 군사학과 훈육담당 교수들이 이 모델을 기초로 하여 실증적인 검증과 보완이 필요하고 지속적인 분석과 보완이 되어야 할 것이다.

• Nuclear Engineering and Technology
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• 제50권1호
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• pp.145-150
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• 2018

A new methodology, the crack-spallation model, has been developed to analyze gas-solid reactions dominated by crack growth inside of the solid reactant and spallation phenomena. The new model physically represents three processes of the reaction progress: (1) diffusion of gas reactant through pores; (2) growth of product particle in pores; and (3) crack and spallation of solid reactant. The validation of this method has been conducted by comparison of results obtained in an experiment for oxidation of $UO_2$ and the shrinking core model. The reaction progress evaluated by the crack-spallation model shows better agreement with the experimental data than that evaluated by the shrinking core model. To understand the trigger point during the reaction progress, a detailed analysis has been conducted. A parametric study also has been performed to determine mass diffusivities of the gas reactant and volume increase constants of the product particles. This method can be appropriately applied to the gas-solid reaction based on the crack and spallation phenomena such as the voloxidation process.

• 시스템엔지니어링워크숍
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• 통권4호
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• pp.59-64
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• 2004

• 한국산업융합학회 논문집
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• 제22권4호
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• pp.387-394
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• 2019

This paper presents an analytical study on the strength and stiffness of various types of truss structures. The applied models are triangular-like opened truss-wall triangular model (OTT), closed truss-wall triangular model (CTT), opened solid-wall triangular model (OST), and hypercube models defined as core-filled or core-spaced cube. The models are analyzed by numerical model analysis using DEFORM 2D/3D tool with AISI 304 stainless steel. Then, the ideal solutions for stiffness and strength are defined. Finally, the relative elastic modulus of the core-spaced model is obtained as 0.0009, which is correlated with the cancellous bone for the relative density range of 0.029-0.03, and the relative elastic modulus for the core-filled model is obtained as 0.0015, which is correlated with cancellous bone for the relative density range of 0.035-0.036. For the relative compressive yield strength, the OTT reasonably agrees with the cancellous bone for the relative density of 0.042 and the relative compressive strength of 0.05. The CTT and OST are in good agreement at the relative density of 0.013 and the relative compressive yield strength of 0.002. The hypercube models can be used for the cancellous bone for stiffness, and the triangular models can be used for the cancellous bone for strength. However, none of the models can be used to replace the compact bone because it requires much higher stiffness and strength. In the near future, compact bone replacement must be further studied. In addition, previously mentioned models should be developed further.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.167-172
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• 2006

Recently, wire-EDM became a necessity for many engineering applications, particularly in the dies making. No-Core cut process is helpful for operations in which falling slug can jam the machine or wire. In this paper a proposed CAM system (called NCPP) is introduced, to overcome the limitations of the existing CAM systems in the machining of No-Core cut. The proposed CAM system (NCPP) provides pocketing of No-core cut and optimal selection of the position of starting hole (wire threading point), to minimize toolpath length. It was written for data exchange between CAD-CAM-CNC machines. This data model will become part of the ISO (Data model for Computerized Numerical Controllers) international standard. The NCPP system has been implemented in Visual C++. Many examples are used to illustrate NCPP system. The results show that, NCPP saves the machining time by significant value. This value depends on the shape and complexity of the workpiece that is being cut.

• Agricultural and Biosystems Engineering
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• 제7권1호
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• pp.8-12
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• 2006

This study was conducted to develop a real-time internal quality evaluation technique for Korean red ginseng using NIR spectroscopy while they were moving to be graded. Internal qualities of Korean red ginseng were defined by color, amount of white core and cavity in the red ginseng. To evaluate the internal quality, PLS (Partial Least Square) model was developed. Spectrum saturation can be occurred when most red ginseng has a sound internal quality expressed by higher light transmittance ratio, but that could not found in the ginseng of internal white core under the same light situation. And, if spectrum saturation is obtained, it is hard to identify the exact information of internal quality. In order to evaluate of the internal quality regardless of having internal normal core or white core, an integral time controlled method was used to obtain traditional spectrum. This procedure was applied in real-time process when red ginseng was moving to be graded in the line. Among the 450 samples including 223 internal normal ginsengs and 227 internal white core ginsengs, 315 ginsengs (70%) were used to develop a calibration model and 135 ginsengs were spent to validate the model. The result of quality evaluation by the model was very good showing SEP and bias were 0.3573 and 0.0310, respectively, and the accuracy was 95.6%.

• 한국초등과학교육학회지:초등과학교육
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• 제35권4호
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• pp.426-441
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• 2016

The purpose of this study was getting the information for successful application to the national curriculum and students' core competencies enhancement, through investigation about competencies discussed in 2015 revised national curriculum development process and analysis about perception of 150 elementary school teachers in study. The results were as follows : Communication skill is considered to be the most important. Thinking ability what has been important traditionally is the middle of the rankings. Elementary school teachers think that a competency is specific to a subject. From this point of view, Creative/Scientific Problem-Solving Ability is the most important in science. They think that the enhancing of the ability of inquiry performance is highlighted in current science class. On elementary school teachers' awareness, inquiry model is the most effective in enhancing of scientific thinking and the ability of inquiry performance. And STS instruction model is in the other. PBL learning model and experimental inquiry model is the most effective in enhancing a competency has the highest feasibility like scientific thinking or the ability of inquiry performance.

• 가정과삶의질연구
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• 제24권6호
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• pp.17-31
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• 2006

The purpose of this study was to develop the model of consumer satisfaction with educational services in higher education on the basis of expectation-disconfirmatiom theory. The major findings were as follows : 1. The level of consumer satisfaction with educational services in higher education was low. Among the four dimensions of the educational services in higher education, the level of consumer satisfaction was the highest with 'education' and lowest with cost. 2. In the model of national university, the perceived performance of the core service, the disconfirmation of the core service, the perceived performance of the additional service, the disconfirmation of the additional service had a casual effect. The perceived performance of the additional service had the greatest casual effect among them. 3. In the model of private university, the perceived performance of the core service, the disconfirmation of the core service, the perceived performance of the additional service, the disconfirmation of the additional service had a casual effect. The perceived performance of the core service had the greatest casual effect among them.