• Journal of the Society of Naval Architects of Korea
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• v.38 no.4
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• pp.48-55
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• 2001

In this paper, sensitivity analysis for the coupled axial and torsional undamped free vibration of ship propulsion shafting is proposed. The purpose of this study is to effectively and optimally design the resonance frequencies of propulsion shafting affecting barred speed range of main engine by modifying the diameters of intermediate and propeller shafts. The presented method is validated by the sensitivity analysis for the natural frequencies of propulsion shafting of two real large merchant ships. In addition, the changes of natural frequency and resonance main engine speed are discussed in case that the diameter is varied within the range regulated by the rule of shipping register.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.237-243
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• 1997

전 세계가 하나의 Global 시대로 전환되면서 국적에 관계없이 기업의 생존이 소비자들의 욕구 를 충족시키는 능력에 따라 결정되는 시대가 되었다. 우리나라의 경우에도 경제협력개발기구(OECD)에 가입한 상황에서앞으로 21C는 외국기업 및 제품들이 자유경쟁적으로 우리시장에 선 보이게 될 전망이 며 우리기업의 제품도 외국에서 다른나라 제품과 치열한 경쟁을 하여야 할 전망이다. 따라서 우리나라 에서도 질이 나쁜 수입품으로부터 국내제품과 소비자를 보호하고 외국으로 수출된 국내제품이 그 나라 에서 이미 시행되고 있는 규제들에 의해 피해를 입지 않ㄷ록 하는 방안이나 정부규제가필요하게 되었는데, 그 중에 대표적인 것이 제조물 책임법(Product Liability)인 것이다. 본 연구에서는 첫째, 외국의 제조물 책임법 시행 현황 및 우리나라 제조물 책임법 시행안에 대해 조사하였으며 둘째, 국내외 제조물 책임 사고 사례를 수집하여 제조물책임법 시행이 소비자와 기업에 미치는 영향등에 대해 분석하였다. 연구결과, 이미 제조물책임법이 시행되어 정착화 되어있는 선진 여러나라의 경우 각국의 제조물책임법 내용은 그 나라의 국가경제, 사회적여건, 자국민을 보호한다는 관점에서 조금씩 차이점을 보이고 있었으며 제조물책임법의 영향 또한 각국의 상황에따라 긍정적 혹은 부정적 영향을 끼치고 있었다. 우리나라의 경우 제품의 안전성을 향상시키기 위해서는 정부의 체계적 정책수립 뿐만 아니라 기업의 제조물책임에 관한 인식 전환 및 대책이 필요한 것으로 조사되었다.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.3
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• pp.29-38
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• 2009

n the event of an earthquake, additional stresses can occur in the continuous welded rails (CWR) of High-speed railway (HSR) bridges due to relative displacements at expansion joints, and this stress can cause derailment. The amplification of ground motion occurs as a result of site effects, and this is pronounced at the site of a soft surface soil layer and of a rigid surface soil layer over a soft one. As a result, the amplified ground motion leads to an amplified seismic response in HSR bridges. A change in bridge pier height affects the seismic behavior of the bridge. A HSR bridge with gravel ballast tracks will show different dynamic behavior during an earthquake than one with concrete ballast tracks. The seismic responses of HSR bridges and their CWR are analyzed considering the derailment-inducing factors.

• Computational Structural Engineering
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• v.10 no.1
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• pp.149-158
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• 1997

This paper presents the illustration of application under attached point mass to the special orthotropic plates with a pair of opposite edges simply supported and the other pair of opposite edges free. Design engineers need to calculate the natural frequencies of such elements but obtaining exact solution to such problems is very much difficult. Pretlove reported a method of analysis of beams with attached masses using the concept of effective mass. This method, however, is useful only for certain simple types of beam. Therefore, considering the method has been developed by D. H. Kim(1974) is simple, accurate, and very effective for the plates with arbitrary boundary conditions and irregular sections, this paper calculates the natural frequencies of composite laminated plate under attached point mass/masses.

• Journal of Korean Society of Archives and Records Management
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• v.14 no.4
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• pp.37-62
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• 2014

This study aims to discuss the paradigm shift of the right to know and to analyze the government 3.0 policies of the Park Gun-Hae's administration. The study analyzes the preceding researches on the rights to know and freedom of information. It also defines the concept of the right to know in both broad and narrow senses. Furthermore, the history of people's right to know is analyzed and divided into three different stages. Then, the outcomes and limitations of government 3.0 during Park Gun-Hae's administration are explored. As a result, the study discusses the dangers and the future tasks of government 3.0 in terms of quality, gathering, and security of public information.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.39-43
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• 2020

Currently, the nation's military is facing a real threat due to a reduction in military service resources and shorter service periods. Based on the military view that puts security first, the military tried to draw its impact and implications on the future army by reflecting the general objective content that the Ministry of National Defense and other government agencies and international agencies share. In other words, this study looks at the direction of the perception of mainstream perspectives (realism, liberalism) on international order, and presents the direction and framework for establishing future security strategies for the Korean Peninsula on the basis of military relevance that reflects the essential characteristics of military organizations contributing to national security on the theory and prospects of international order.

• Computational Structural Engineering
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• v.10 no.2
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• pp.171-178
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• 1997

Three-dimensional dynamic analyses of underground openings subjected to explosive loadings are carried out. Dynamic analyses consist of two steps; one-dimensional source calculation and three-dimensional tunnel analysis. One-dimensional source calculation includes explosive charge and the free field surrounding rock. The input pressure time history for three-dimensional tunnel analysis is obtained from the companion one-dimensional source calculation. The computer program MPDAP-3D incorporated this analysis capability. It is shown that the computer program is a useful tool for the analysis of the structural safety evaluation of underground openings during construction by drill and blasting method.

• Magazine of the Korea Concrete Institute
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• v.8 no.6
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• pp.205-212
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• 1996

This paper presents progressive fracture analysis of concrete using boundary element method and its stabilizing technique. To determine ultimate strength and to predict nonlinear behavior of concrete during progressive crack growth, the modelling of fracture process zone is done based on Dugdale-Barenblatt model with linear tension-softening curve. We regulate displacement and traction boundary integral equation of solids including crack boundary and analyze progressive fracture of concrete beam and compact tension specimen. Also a numerical technique which considers the growth of stress-free crack of concrete during the analysis and removes snapback of postpeak behavior is proposed.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.2
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• pp.233-238
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• 2015

In this paper, we proposed that immersive audio effect method using the effective noise to improve engagement in free-viewpoint TV(FTV) service. In the basketball court, we monitored the frequency spectrums by acquiring continuous audio data of players and referee using shotgun and wireless microphone. By analyzing this spectrum, in case that users zoomed in, we determined whether it is effective frequency or not. Therefore when users using FTV service zoom in toward the object, it is proposed that we need to utilize unnecessary noise instead of removing that. it will be able to be useful for an immersive audio implementation of FTV.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.201-203
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• 2007

본 논문에서는, 연료전지 시스템의 기계적 주변장치 (MBOP)와 전기적 주변장치 (EBOP)의 최적 설계를 위해서 PEMFC 스택을 전기화학반응을 기초로 모델링한다. 모델링을 위해 기본적인 PEMFC의 구조와 동작 원리를 설명한다. 연료전지의 이론적 최고 전압인 평형전위를 깁스 자유에너지와 네른스트 방정식으로 유도한다. 전류밀도에 따른 전압 손실인 활성화, 저항, 농도 분극현상을 표현하기 위해서 수식을 유도한다. 수소가 이온화되지 못하고 산소극으로 넘어가서 발생되는 연료손실 및 내부전류와 지속적인 정역반응인 교환전류도 모델링된다. 평형전압에서 각 분극을 뺀 실제 운전 전압을 시뮬레이션하고, 유량과 압력에 따른 출력 특성을 시뮬레이션 한다. 부하변동 시 출력특성을 시뮬레이터와 실험결과로 비교한다.