• Computational Structural Engineering
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• v.9 no.4
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• pp.135-140
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• 1996

Single angle or channel with thin-walled open section can be used as compression member for example as web member in truss. In this case the inevitable eccentricity due to fabrication is commonly neglected in structural design. However eccentricity effect should be considered in the member design, especially in case of compression member. The critical loads of compression members that buckle by twisting or by a combination of bending and twisting are to be determined by solving governing differential equations. In this paper, the investigations are limited to the rolled channels([), equal-leg angles(L), lipped channels(C) and the applied loads are assumed to have some eccentricities.

• Journal of Korean Association for Spatial Structures
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• v.7 no.4
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• pp.63-72
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• 2007

As business of steel consuming industries is freshly booming in domestic and foreign countries especially in China, the price of steel plates comes to very high compare with the other materials. The HR Plates made from hot rolled coils is lower steel plates in price. In this study, material characteristics of HR Plates is investigated and availabilities of HR Plates for steel bridges as sub member or a main member is discussed. No difference between steel plates and HR Plates with thickness up to 22mm is found in most characters such as cutting operation, fabrication and even welding. As sub member in steel box girders, the application ratio and the loss ratio of HR Plate is investigated as about $10{\sim}15%$, average $10{\sim}15%$ respectively.

• Journal of the Society of Disaster Information
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• v.14 no.4
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• pp.492-500
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• 2018

Purpose: In this paper, based on this background, the main purpose of studying the behavior of concrete slab reinforced with new material fiber in impact loading is investigated by AFRP using aluminum fiber. Results: Research on the use of new materials as reinforcing materials for concrete members has been carried out in many fields such as flexural and shear tests under static loading, fatigue loading under cyclic loading, and application to PC beams. However, And the issue of plate elements is still at a basic stage. Conclusion: In this paper, the dynamic behavior of reinforced concrete slabs is investigated by using AFRP rod reinforced with aluminum fiber.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.253-259
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• 2021

Plastic wastes generated from household waste are separated by mixed discharge with foreign substances, and recycling is relatively low. In this study, the effect of the ratio and content of mixed plastic waste coarse aggregate(MPWCA)s and mixed plastic waste fine aggregate(MPWFA)s filled with blast furnace slag fine powder on the slump and compressive strength of concrete was evaluated experimentally. The MPWCAs were found to have a similar fineness modulus, but have a single particle size distribution with a smaller particle size compared to coarse aggregates. However, the MPWFAs were found to have a single particle size distribution with a larger fineness modulus and particle size compared to fine aggregates. Meanwhile, the effect of improving the density and filling pores by the blast furnace slag fine power was found to be greater in the MPWFA compared to the MPWCA. As the amount of the mixed plastic waste aggregate(MPWA)s increased, the slump and compressive strength of concrete decreased. In particular, the lower the slump and compressive strength of concrete was found to decrease the greater the amount of MPWFA than MPWCA when the amount of MPWA was the same. This is because of the entrapped air and voids formed under the angular- and ROD-shaped aggregates among the MPWFAs. On the other hand, the addition of the admixture and the increase in the unit amount of cement were found to be effective in improving the compressive strength of the concrete with MPWAs.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.5-14
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• 2013

Coarse granular geomaterials containing large gravels are broadly used for construction of large geotechnical systems such as dams, levees, railways and backfills. It is necessary to evaluate deformation characteristics of these materials for dynamic analysis, e.g. seismic design. This study presents evaluation of dynamic deformation characteristics of coarse materials using large scale resonant column testing apparatus, which uses specimens with 200 mm in diameter and 400 mm in height, and the effects of gradation characteristics on maximum shear modulus, shear modulus reduction curve and damping characteristics were investigated. From experimental study using rock-fill materials for a dam, we could see that the largest or mean particle size affects the shape of shear modulus reduction curve. When the specimens are prepared under the same conditions for maximum particle size, the coefficient of uniformity affects the confining stress exponent of maximum shear modulus. It could be concluded that the maximum particle size is an factor which affects shear modulus reduction curve, and that the coefficient of uniformity is for small strain shear modulus, especially for the sensitivity to confining stress.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.62-69
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• 2023

Re-damage is frequently occurring for various reasons, including material factors, external factors, and factors caused by poor construction in concrete cross-section restoration work, so it is necessary to identify the cause and improve it. Cement-based materials are the most commonly used maintenance materials for concrete structures, and in particular, additional cross-sectional restoration work may be carried out due to re-damage such as cracks and excitement due to dry contraction of the repair material. In this study, a basic study was conducted to identify the characteristics of concrete while diversifying the maximum dimensions and assembly rate of thick aggregates to examine the effects of using thick aggregates in repair materials. As a result, the slump of concrete increased as the maximum size of thick aggregates increased, and the amount of air content was measured 1.88 to 2.35 times higher in the mixing using aggregates with a maximum aggregate size of 5 mm or more compared to the mixing group with a maximum aggregate size of 10 mm or more. It was found that compressive strength was greatly affected by the performance rate of thick aggregates. The compressive strength was measured the highest in the mixture using thick aggregates with the highest performance rate of 20 mm, and the compressive strength of the mixture with the lowest performance rate was more than 45%. As a result of the dry shrinkage measurement, the dry shrinkage was the lowest as the performance rate of the thick aggregate increased according to the change in the maximum dimensions and assembly rate of the thick aggregate, and the lowest performance rate was the largest in the mix. Through this study, it was confirmed that adjusting the particle size by diversifying the maximum dimensions and assembly rate of thick aggregates used in concrete structure repair materials can improve strength and workability and reduce dry shrinkage.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.322-324
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• 2004

PLE 방법론은 단일 제품이 아니라 유사한 제품들간의 공통성(Commonality)과 가변성(Variability)을 개발하고 관리하며 소프트웨어 개발 전체 생명주기에 걸쳐 부품을 조립하는 형태로 만들어진다. 또한 PLE 방법론은 재사용 단위가 가장 큰 방법론이기 때문에 최근에는 소프트웨어 업계에서 주목을 많이 받고 있다. 따라서 소프트웨어 재사용 분야가 점점 다양화되면서 어플리케이션의 특성에 적합한 프로세스에 대한 요구가 늘어나고 있다. 어플리케이션 과정은 요구사항 정의에 따라서 설계가 되어야 하고 이렇게 설계가 된 요구사항 정의와 핵심자산의 Gap 분석을 통해 정제된 설계를 얻을 수 있다. 하지만, 현재는 체계적인 절차와 기법에 대한 연구가 많이 미흡한 상태이다. 이렇게 체계적인 절차와 기법이 있다면 어플리케이션을 개발하는데 있어 보다 효율적이고, 보다 완성도 높은 어플리케이션이 개발 될 것이라고 기대한다. 따라서 본 논문에서는 제품계열공학의 핵심자산과 어플리케이션간의 Gap 분석 절차를 제안하고자 한다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.19-22
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• 2004

한정된 자원과 환경보존에 대한 중요성으로 인해 회수물류에 대한 관심이 점차 증가하고 있다. 본 논문에서는 역 물류의 다양한 형태 중 부품을 재활용하는 재생산과 원자재의 재활용 프로세스가 포함된 역 물류 네트워크를 제안한다. 제안된 역 물류 네트워크에서 수명이 다한 제품은 제조업자에 의해 수거되어 분해 된다. 분해 된 부품들 중 재사용이 가능한 일부는 재생산 프로세스에 투입되고 나머지 부품들은 재활용 프로세스를 거쳐 원재료 공급업자에게 역으로 판매되거나 폐기된다. 재생산프로세스에서는 분해 후 가공된 부품과 공급업자로부터 구매한 새 부품을 조립하여 제품을 생산한다. 본 논문에서는 제시된 역 물류 네트워크상에서 수거, 저장, 분해, 폐기, 재 가공 프로세스 비용을 산출하여 역 물류의 총 비용을 최소화 하는 부품의 재 사용량 결정 모델을 제시한다. 마지막으로 수치실험을 통해 제안된 모델의 적합성과 실용성을 검증한다

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2083-2086
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• 2002

시스템이 복잡해지고 대형화됨에 따라 소프트웨어 생산성, 품질, 효율성을 높이기 위해서 부품화와 재사용의 특성을 지닌 컴포넌트가 여러 응용프로그램에서 개발되고 있다. 따라서 컴포넌트기반 소프트웨어공학에서는 컴포넌트를 분류, 검증, 검색하기 위한 컴포넌트 명세화 방안과 컴포넌트 기반의 개발을 위한 개발공정에 대해 많은 연구가 요구되고 있다. 이에 본 논문에서는 컴포넌트의 실제 재사용을 위해 컴포넌트의 조립 시점 정보를 나타내는 인터페이스 명세 중심의 컴포넌트 저장소 모델을 제안한다. 본 논문에서 제안하고 있는 컴포넌트 명세에는 인터페이스 정보 뿐 아니라 상속 등과 같은 재사용에 대한 정보와 컴포넌트들간의 결합관계를 나타내는 상호작용에 관한 정보를 포함하며, 이 명세는 이식성 및 구조적 표현이 뛰어나고 다양한 형태의 문서로 확장 가능한 XML을 사용하여 기술한다.

• Journal of Digital Contents Society
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• v.4 no.1
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• pp.101-113
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• 2003

IDS(Intrusion Detection System) evasion is a technology which uses vulnerability of IDS in order not to be detected by IDS. In this paper, at first, we classify IDS evasion technology. Second, we propose detection model of IDS evasion technology. Finally, we design and implement IDS evasion detection system with packet reassemble function.