• Computational Structural Engineering
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• v.6 no.1
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• pp.17-25
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• 1993

여기에서는 진동기초에 관한 해석모델로 실무에서 널리 사용되고 있는 참고문헌[1]의 진동기초 해석모델에 관한 문제점들(로킹진동, 보와 기둥의 연결부에 관한 모형화, 기계 질량의 위치지정, 작용하중의 형태)을 알아보았고, 이 문제점들을 개선한 해석모델들을 소개하였다. 참고문헌[1]의 진동기초 해석모델(모델A)과 개선된 해석모델들간의 해석결과로부터 기존의 해석모델 A는 실제보다 훨씬 긴 고유진동주기를 가져오기 때문에 진동기초에 대한 해석모델로서 부적합함을 알 수 있었다. 여기에서 소개한 해석모델중 모델 D를 이용하면 실제에 매우 가까운 진동기초의 고유진동주기와 모드형상을 얻을 수 있을 것으로 생각되며 기계회전 속도의 변화에 의한 진동기초 고유진동수와의 공진현상에 대한 세심한 검토가 필요하다.

• Computational Structural Engineering
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• v.1 no.1
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• pp.103-112
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• 1988

In this study, the earthquake response of building structures with foundation uplift was investigated. The Winkler foundation model and two-spring model are widely used to represent the interaction between foundation mat and soil. While the analysis using the Winkler foundation model results in more accurate prediction, it requires a complex procedure and longer computation time. In this study, an equivalent two-spring model(S model) is proposed. The S model can represent the Winkler foundation model more accurately and the analysis using the S model is simpler and more effective. The S model is derived by simplifying the nonlinear moment-rotation relationship of foundation mat. The dynamic responses predicted by the S model gave a good agreement to those of the Winkler foundation model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.46-49
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• 2015

세월호 이후 안전교육의 중요성이 강조되고 있어 해양안전 기초교육 표준 모델을 정립 할 필요성이 제기되고 있다. 해양산업계에서는 선원법에 의해 기초안전교육, 상급안전교육으로 법정 교육으로 강제하고 있으며, 해기사에 대해서는 BRM 교육이 실시되고 있다. 이를 일반 국민에게 적용하기 위한 바다 물놀이 안전수칙, 선박 안전수칙, 재난선박 안전수칙에 대한 표준 교육 모델을 제시하여 교육 현장에 적용하고 해양안전 문화확산의 기초 자료로 사용하고자 한다.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.6
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• pp.25-32
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• 2002

In the seismic designing of bridges, the pile foundation of bridge piers generally have been modeled to have a fixed end for its convenience and conservative designing. The fixed-end assumption, however, produces very conservative results in terms of the pier forces. Therefore, many other design methods are evolved to consider the flexibility of the pile foundation. In this study, the response spectrum analysis was performed for a bridge pier having a pile foundation. The shear force, moment, and displacement, which occurred at the pier column under an earthquake loading, were compared to analyze the effects of the modeling method, soil condition and the input earthquake response spectrum. In most cases, the fixed-end model gives larger design forces than flexible foundation models. However, when a long period earthquake is applied to the bridge pier on a soft clay foundation, it is found that the flexible foundation models give larger design forces than the fixed-end model. In the end, the reliability of several flexible foundation models was verified by comparing their results with those of a numerical analysis that considers the soil-structure interaction phenomenon in a rigorous manner.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.1
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• pp.167-176
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• 1991

Finite element programs are developed, adopting the hyperbolic model and the Cam-clay model. In the hyperbolic model, a new model taking into account the volume change during shear is proposed and a new technique considering the density change underneath a footing is proposed. And a computing algorithm considered as more reasonable than existing one is presented. In the Cam-clay model, the deveoloped program is applied to sand, the case not recorded much, and then it is tried to analiza the behavior of sand from the viewpoint of the critical state concept. For this, the conventional CD triaxial compression tests and the footing model tests are carried out. The results are improved by 60 percent by using the modified hyperbolic model proposed. When the Cam-clay model is applied to sand, a model reflecting the overconsolidation effects and a computing algorithm accounting for the strain softening are needed. The results obtained by using the Cam-clay model are not much influenced by the value of the initial poisson's ratio, but those of the modified hyperbolic model are much influenced by that. So th values of the initial poisson's ratio must be selected deliberately in the numerical analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.13-18
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• 1993

The purpose of this study is to analyze the seismic effects of Lead Rubber Bearing base isolators on bridges. Base isolation is the tool to minimize the effect of earthquake before the seismic force is transfered to the structure. Currently, many structures including the buildings, power plants, and bridges, were built and planned with base isolation method. The simple model is developed for bridges with Lead Rubber Bearings. Equations of motion are solved by Newmark ${\beta}$ method. Springs representing the base isolators are assumed as bilinear springs and piers are modeled as nonlinear springs implementing Q-HYST model. Analysis is performed for the selected bridge. El Centro (N-S) earthquake(1940) is used. Deck displacement, pier ductility and pier shear force are calculated for the various Lead Rubber Bearings.

• The Journal of Korean Association of Computer Education
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• v.11 no.4
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• pp.1-12
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• 2008

This paper proposes basic algorithmic thinking based problem models applicable immediately without additional learnings and it problems basic problems and evaluation methods using material factors in an elementary course of mathematics For these purposes, an algorithmic thinking based problem model and it's basic problem models are proposed based on flowchart design methods with 5 degrees of difficulties. And algorithmic thinking based basic problems are developed by applying the proposed basic problem models into material domain in an elementary course of mathematics. And this paper proves the validity of developed basic problems in defining then as algorithmic thinking based basic problems through experiments and statistical analyses. The experimental results are analyzed in views of variety and effectiveness evaluation of answer algorithms and suitability of allocating 5 degrees of difficulties to the developed basic problems.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.255-267
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• 2021

The purpose of this study is to present basic data for systematic and effective basic medical education by developing a flipped learning class design model using smart tools and verifying its validity. To this end, in this study, a model proposal was developed based on literature review, and its validity was verified through expert review and field application. In this study, as a flipped learning class design model using smart tools, RECIPE(R: Ready, E: Establish a Plan, C: Create and Connect Media, I: Into the Classroom, P: Process-focused Assessment, E: Evaluation) model was developed. This model is a model that enhances the learning effect by applying an appropriate smart tool at each stage of designing flipped learning. As a result of applying this model to the development of'Anatomy'and'Neuroscience'lectures in the first semester of 2019, students' interest and satisfaction are high, and it is proposed as a specialized model in the field of basic medicine. Therefore, the RECIPE model developed in this study can be applied to various basic medicine-related classes, and it is expected that students will be able to understand basic medicine through the design of the flipped learning class based on this.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.14 no.5
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• pp.561-570
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• 1989

In this paper, we describe the theoretical analysis and optical implementation of real-time associative memory based on the modified Hopfield neural network model by using a commerical LCTV connected to computer graphic as the real-time memory mask and adding one mask line to the momory mask in order to optically obtain the time-varing thresholding values of the modified Hopfield model.

• Korean Journal of Optics and Photonics
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• v.10 no.4
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• pp.335-341
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• 1999

We fabricate acrylamide photopolymer as a holographic recording material and investigrate photobleaching characteristics. To explain the photobleaching kinetics of photopolymer we adopt two models of the Beer-Lambert law and optical transmittance based on rate equations obtained from a simplified energy-band model. The Beer-Lambert law is in good agreement with the experimental results in a first short-time region but not in long-time region. But the optical transmittance model based on rate equations explains the experimental results very well in both short-and long-time regions.