• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.81-87
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• 1990

In this paper, a new design method in which transient response behavior of a servo~system can be improved, is proposed using a bilinear transformation method which assigns the poles of the closed-loop system in a specified region. The servo-system is a dynamic system which follows the given reference input automatically. In the above meaning, the design of a servo-system is similar to a regulator design problem for the extended system which is resulted from the given system and the reference input by the well known internal moel principle. In the design problem of servo control system, it is supposed that the proposed design method has more practical meaning in comparison to the other design methods, in the views of assigning the characteristic roots of the closed loop system in a specified region satisfying a design specification for the given transient response rather than in the exact positions of the poles. The applicability of the design method proposed in this paper was proved by the simulation results for the angle control problem of an electrical servo mechanism.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.685-690
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• 2008

In numerically evaluating the thermal performance of the heat exchanger, numerical values of thermodynamic properties such as temperature, pressure, specific volume, enthalpy and entropy are required. But the steam table or diagram itself cannot be directly used without modelling. In this study the applicability of neural networks in modelling superheated water vapor was examined. The multi-layer neural networks consist of an input layer with 2 nodes, two hidden layers with 15 and 25 nodes respectively and an output layer with 3 nodes. Quadratic spline interpolation was also applied for comparison. Neural networks model revealed smaller percentage error compared with spline interpolation. From this result, it is confirmed that the neural networks could be a powerful method in modelling the superheated water vapor.

• The Journal of Korean Medical History
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• v.14 no.1
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• pp.109-124
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• 2001

"Euibangyoochui" is a great medical encyclopedia composed of 91 symptoms and signs of diseases which classified 150 kinds of reference books. It consisted mainly of fifty thousands of herbal prescriptions and therapeutics but it deals with other treatments like diet therapy, precautions, acupuncture and moxibustion, physical and breathing exercises as well. Unlike other medical references, this book made up these treatments as independent chapters. We tried to catch the meanings and characteristics of each chapters.

• The Journal of Korean Association of Computer Education
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• v.23 no.3
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• pp.9-15
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• 2020

This study analyzed high school informatics textbooks that were developed based on the 2015 Revised National Curriculum. Content analysis was adopted to analyze the organization system of the textbooks. Learning objectives were also analyzed according to Anderson's taxonomy of educational objectives. Through content analysis, it was revealed that the textbooks were composed of activities, differentiated learning, and small group learning to promote core competencies. The analysis of learning objectives of the textbooks showed that 'understanding' (41%), 'developing' (20%), and 'applying' (18%) were the three highest criteria in terms of cognitive processes; in terms of type of knowledge, conceptual knowledge accounts for the highest(45%), followed by procedural (32%), and factual (12%). Further methods to improve the textbook quality is proposed based on the results from this analysis.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.744-758
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• 2021

This study is aimed at identifying the possibility and effectiveness of teaching methods education for professors through the development of online teaching content and providing important implications for future online teaching content development and utilization strategies by looking at the differences in the experience and needs of professors who have taken online teaching content. A university surveyed 83 professors who took the seven teaching contents developed between 2015 and 2018, and took them from 2017 to 2019. As a result of the study, professors often took online teaching content for self-development purposes, were satisfied with the overall content, and cited the low psychological burden and resistance of education through personal learning, and the possibility of repeated learning online. The differences between importance and execution in content composition, the areas of statistically significant difference were easy-to-understand delivery, appropriate and sufficient examples, interest and motivation, facilitating interaction between learners, appropriate difficulty, reflection of current trends, appropriate presentation order and ethical composition. The importance level recognized by professors in the area was higher than execution level. In conclusion, opinions for improving online teaching content were appropriate and sufficient examples in the area of content composition, interest and motivation, and reflection of the latest trends. In the area of ease of use, there was stable playback, relay function, and location-independent.

• Archives of design research
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• v.16 no.4
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• pp.207-214
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• 2003

The reason why rhetoric is important to a moving image is that a moving image communicates through non-verbal communication language. At first, rhetoric in a moving image functions to be persuasive in the story of a moving image. Second, rhetoric works to enhance an aesthetic value for a moving image. Thus we feel good when we are watching a moving image with well embeded rhetoric. On the other hand, we see extened rhetoric to enhance an imaginary because of a hollywood movie with visual effect and a digital movie. Visual images now formed using more signigier compared to signified for signification. Also we see that every signifier structured metaphorically to function as a sign. In this paper, 1 am going to explain the principles of rhetoric applied to a moving image so that we can better understand a signification on visual image.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.55-58
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• 2009

본 논문에서는 독립적으로 구성된 유한요소 모델을 결합하기 위하여 계면에서 불일치 격자들을 처리하는 기법을 소개하고자 한다. 불일치 격자들로 인하여 요소들의 침투와 틈이 발생할 수 있고 일반적인 유한요소를 사용하면 계면에서 변위의 연속성과 하중전달 조건들을 만족시키기가 불가능하게 되는데 계면에서 정의된 계면요소를 사용하여 결합을 위한 조건들을 만족시킬 수 있게 된다. 요소들의 침투와 틈이 없는 연속적인 계면을 정의하고 여기에 부합하는 계면요소를 구성하며 유한요소 형상함수와 다른 계면요소 형상 함수를 사용하게 되면 독립적으로 구성된 분리 영역들을 자연스럽게 결합할 수 있게 된다. 계면요소는 연속성, 적합성, 완전성 등에서 유한요소와 유사한 특성을 갖으며 추가적인 자유도 없이 불일치 격자를 결합하게 된다. 계면요소법을 사용하여 분리된 영역의 결합이나 전체-국부 해석 그리고 유체-구조물 상호작용해석 등에 적용되어 유용한 방법으로 사용될 수 있게 된다.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.31-42
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• 2015

The plastic stress distribution method and the strain compatibility method are the two representative methods to calculate the P-M interaction strength of RCFT (rectangular concrete filled tube) columns. The plastic stress distribution method is approximate while the stress compatibility method should approach the exact solution if accurate constitutive relations of the materials involved are used. Recent study by the authors pointed out that, because of lack of accurate constitutive model for the concrete confined by the rectangular steel tube, no strain compatibility method according to the current structural provisions provides a satisfactory prediction of the P-M interaction strength of RCFT columns under various material combinations. An empirical constitutive model which can capture the stress-strain characteristics of the confined concrete of RCFT columns is proposed based on analyzing extensive exisitng test database. The key idea was to define the concrete crushing strain as a function of steel-to-concrete strength ratio and width-to-thickness ratio of steel tube. It was shown that the proposed model leads to more accurate and more consistent prediction of the P-M interaction strength of RCFT columns under general design conditions.

• Geophysics and Geophysical Exploration
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• v.5 no.3
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• pp.206-216
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• 2002

The finite element method (FEM), a powerful numerical modeling tool for solving various engineering problems, is frequently applied to three-dimensional (3-D) modeling thanks to its capability of discretizing and simulating the shape of model with finite number of elements. Considering the accuracy of the solution and computing time in modeling of engineering problems, it is preferable to construct physical continuity and simplify mesh system. Although there exist systematic mesh generation systems for arbitrary shaped model, it is hard to model a simple cylinder in terms of 3-D coordinate system especially in the vicinity of the central axis. In this study I adopt cylindrical coordinate system for modeling the 3-D model space and define the origin of the coordinates with mathematically clear coordinate transformation. Since we can simulate the whole space with hexahedral elements, the cylindrical coordinate system is effective in handling the 3-D model structure. The 3-D do resistivity modeling scheme developed in this study provides basie principle for borehole-to-surface resistivity survey, which can be a useful tool for the application to environmental problem.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.61-62
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• 2015

밀리미터파 대역에서 사용하는 대형 안테나 해석 속도를 개선하기 위한 병렬형 행렬 연산법을 제안한다. 기존의 가우스 소거법을 병렬화하기 위해 행렬 분해와 반복법을 이용한다. 또한, 반복법의 수렴성을 높이기 위해 이전 행렬해를 부분적으로 사용하여 분해 행렬을 구성하는 방식도 제시한다. 본 제안법은 OpenMP, MPI, CUDA 등의 병렬법과 함께 사용할 수 있다.