• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.691-699
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• 2002

A study on the evaluationof the proper spacing and required bending rigidity of cross beams in composite multiple I-girder bridge without lateral and sway bracing system was performed. For the purpose, a two-lane 40m simple span and 40+50+40m continuous sample bridge with four girders was designed. For the sample bridges, structural analysis under the design loads including dead load before and after composite, live load, and seismic loads has been performed. The material and geometric nonlinear analysis under dead load before composite has also been performed to evaluate lateral buckling strength of the steel-girder-cross beam grillage. Based on the two phase anlayses, proper spacing and bending righidity of cross beams were proposed.

• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.51-58
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• 2005

Moment frames have been widely used in building construction. In current design codes, concrete moment frames are classified into ordinary, intermediate, and special moment resisting concrete frames (OMRCF, IMRCF, SMRCF)). The objective of this study is to investigate the seismic behavior of columns in ordinary moment resisting concrete frames (OMRCF) and intermediate moment resisting concrete frames (IMRCF). For this purpose 3 story OMRCF and IMRCF buildings were designed and detailed in compliance to ACI 318 (2002) and KCI (1999). In this study the buildings were assumed to be located in seismic zone 1 classified by UBC (1997). This study considered the columns in the 1st story since these columns shall resist the largest axial and lateral forces during an earthquake. Eight 2/3 scale column specimens were made for representing the upper part and lower part of exterior and interior columns of the OMRCF and the IMRCF Quasi-static reversed cyclic loading was applied to each specimen with a constant or varying axial load. Test results show that seismic behaviors of columns are influenced by existence of lap splices, axial force levels, and lateral reinforcement at possible plastic hinging region. However, the effect of such variables strongly co-related to each other.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.141-149
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• 2009

In this paper, quasi-static FDTD method is implemented by FORTRAN programming, and it is used for analysis of body induced current in middle frequencies. The quasi-static FDTD program is validated by comparing the calculation result with analytic solution of the test model, to which it is difficult to apply conventional FDTD. It is confirmed that the time-step is reduced by $5.68{\times}10^6$ times. Using validated numerical technique, body induced current distribution in high resolution 3-D human model is calculated for 20[kHz] magnetic field exposure and 1[MHz] electric field exposure. Also, the effect of grounding condition of both feet on the distribution and amplitude of the induced current is analyzed. It is expected that this research can be applied to various fields including safety assessment of body induced current and development of diagnosis devices using bio-electricity.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.1-10
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• 2004

A study on the evaluation of proper spacing and required flexural rigidity of cross beams in composite two I-section steel girder bridges without a lateral and sway bracing system was performed. Specifically, a 2-lane, 40-m simple span bridge and a 3-span continuous (40+50+10m) bridge were designed, and structural analyses under dead load before and after composite, live, wind, and seismic loads were performed using spacing and flexural rigidity or cross beams as parameters. Through parametric analysis, the effect on the stresses due to the combination of loads and live load distribution was investigated. In addition. material and geometric nonlinear analyses under dead load before composite were performed to evaluate the lateral buckling strength of the steel girders and cross beam. Based on the results or such analyses, the proper spacing and flexural rigidity of cross beams at intermediate points and supports were proposed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.513-518
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• 2016

This paper presents a fast 3D mesh generation method using projection for line laser-based 3D scanners. The well-known method for 3D mesh generation utilizes convex hulls for 4D vertices that is converted from the input 3D vertices. This 3D mesh generation for a large set of vertices requires a lot of time. To overcome this problem, the proposed method takes (${\theta}-y$) 2D depth map into account. The 2D depth map is a projection version of 3D data with a form of (${\theta}$, y, z) which are intermediately acquired by line laser-based 3D scanners. Thus, our 2D-based method is a very fast 3D mesh generation method. To evaluate our method, we conduct experiments with intermediate 3D vertex data from line-laser scanners. Experimental results show that the proposed method is superior to the existing method in terms of mesh generation speed.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.2
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• pp.76-88
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• 2012

In this study, the treatment flow of the recyclables(paper, plastic, metal, etc.) collected and separated from MSW was investigated throughout entire phase from separation and collection to final disposal. Based on the site survey, most recyclables came into six material recovery facilities were comparatively managed well. However, some of recyclables showed irrelatively transportation flow. Because the main income source of the recyclables transportation companies is profit margin between treatment and transportation cost based on economics only therefore, it occurs an unnecessary route and long distance transportation while going to final destination. This unreasonable system should be a serious problem relating establishment of the resource recycling system. As a result of this study, in order to establish the reasonably resource recycling system, recycling center including material recovery facility has to manage the recyclables generated in close range preferentially. Also integrated its treatment system over a wide area will need to be considered as a basic step for the reasonable reasonably resource recycling system.

• The Journal of Society for e-Business Studies
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• v.12 no.4
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• pp.1-15
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• 2007

Traceability links are logical links between individual requirements and other system elements such as architecture descriptions, source code, and test cases. These are useful for requirements change impact analysis, requirements conflict analysis, and requirements consistency checking. However, establishing and maintaining traceability links places a big burden since complex systems have especially yield an enormous number of various artifacts. We propose a feature-oriented requirements tracing method to manage requirements with cost benefit analysis, including value consideration and intermediate catalysis using features. Our approach offers two contributions to the study of requirements tracing: (1)We introduce feature modeling as intermediate catalysis to generate traceability links between user requirements and implementation artifacts. (2)We provide value consideration with cost and efforts to identify traceability links based on prioritized requirements, thus assigning a granularity level to each feature. In this paper, we especially present the results of a case study which is carried out in Apartment Ubiquitous Platform to integrate and connect home services in an apartment complex in details.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2565-2574
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• 2000

The error diffusion method is good for reproducing continuous image to binary image. However the reproduction of edge characteristic is weak in power spectrum analysis of display error. In this paper. we present an edge-enhanced error-diffusion method which include pre-processing algorithm for edge characteristic enhancement. Pre-processing algorithm consists of the difference value between current pixel and local average of original image and weighting function of pre-filter. First. it is obtained the difference value between current pixel and the local average of peripheral pixels(5x5) in original image. Second, weighting function of pre-filter is composed by function including absolute value and sign of difference value. The improved Error diffusion algorithm using pre-processing algorithm, present a good result visually which edge characteristic is enhanced. The performance of the proposed algorithm is compared with that of the conventional edge-enhanced error diffusion by measuring the RAPSD of display error, the egde correlation and the local average accordance.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.497-503
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• 2007

학습의 깊이의 단계를 Bloom은 지식, 이해, 적용, 분석, 종합, 평가라는 6가지의 단계로 나누면서 피상적인 학습과 감이 있는 학습으로 구분하였다. 최근 학습은 면대면 학습에서 뿐 아니라, 웹기반의 학습에서도 피상적인 학습 위주로 이루어진다는 비판을 받고 있고, 웹기반 학습에서는 자기조절 흑은 자기규제의 문제가 가장 큰 문제로 지적 받고 있다. 본 연구에서는 이를 해결하기 위한 방안으로서 감이 있는 학습을 촉진하고, 자기 조절을 촉진하는 메타인지를 웹기반학습에의 인터페이스 디자인에 적용하는 문제를 살펴보았다. 이를 알아보기 위해 메타인지 전략의 가장 핵심 요소인 '자기 점검'의 요소 중 학습 내용들 간의 위계 관계를 보여주는 지도 (MAP) 와 계획세우기를 도와주는 요소 (PLAN)를 기존 연구를 토대로 웹기반의 학습의 인터페이스로 구현하고, 이러한 요소들이 학습, 특히 Bloom이 말한 김이 있는 학습을 촉진하는지를 실험을 통해 살펴보았다. 메타인지를 활용한 웹기반 학습의 효과는 배운 내용의 사후 테스트 점수로 측정되었다. 일반적으로 웹상에서 이루어지는 학습의 일반적인 형태인 학습 중에 확인문제를 푸는 조건 (OX조건)과 확인문제와 학습 내용들 간의 위계 관계를 보여주는 지도를 제시하는 조건 (MAP조건), 이에 덧붙여 사전 계획세우기까지 모두 하는 조건 (PLAN조건)으로 나누어 실험이 진행되었다. 그 결과 첫째, 집단 간 참가자들의 전체적인 학습 점수는 MAP조건이 가장 낮고, OX조건이 중간, PLAN조건이 가장 높은 모습을 보였다. 그러나 이 차이가 통계적으로 유의미하지는 않았다. 또한 모든 조건의 집단에서 행해졌던 학습 중간의 OX점수는 집단별 점수의 차이가 통계적으로 유의미하지는 않았으나, 평균의 차이를 보여주었다. 둘째, 조건별 참가자의 학습 효과는 피상적인 학습수준(암기)에서는 통계적으로 집단 간 유의미한 차이를 보였다. 그러나 감이 있는 수준의 학습(문제해결)에서는 집단 간에 통계적으로 유의미한 학습의 차이를 보이지 않았다. 따라서 깊이있는 학습을 촉진하는 웹기반 학습의 인터페이스 디자인에 대해서는 추후 연구가 필요하다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.4
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• pp.326-333
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• 2014

Internet Services have security issues. To prepare proper security measures for these security issues, security level setting is positively necessary. Until now, we use a security level with CIA (Confidentiality, Integrity, and Availability) Security Levels. However, CIA Security Levels has problems with ambiguous measures for the middle level of security setting. Moreover, security level overlap occurs, in some cases, when user authentications are not done. Additionally, there exist some levels among CIA Security Levels which cannot be applied to Internet services. In this paper, new security level model, CIAA Security Levels with deletion of ambiguous middle level of security setting and addition of authentication to one of security level setting factors, is proposed. The CIAA Security Levels model can be applied to more concrete security measures than CIA Security Levels. The proposed Security Levels model is applicable to almost any on-line services and it can be applied to new online services.