• Journal of Korean Society of Steel Construction
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• v.29 no.4
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• pp.323-330
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• 2017

The pre-engineered building(PEB) construction has been gradually applied to single story buildings as a practical and efficient alternative to conventional buildings. However, there has been a few structure collapse due to suddenly excessive load. Although a structure design requires accurate and professional skills, the PEB system tends to be designed simply because of complexation of structural analysis for connections. This paper shows the finite element analysis(FEA) using ABAQUS software on bolted connection which was previously tested. The FEA condignly simulated the behavior of bolted connection in PEB system and was in close agreement with experimental results. Then the stiffness reduction factor of the bolted joints that can be used in the actual design is presented through the analysis of the joint parameters.

• Computational Structural Engineering
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• v.23 no.6
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• pp.8-14
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• 2010

• Journal of Korean Association for Spatial Structures
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• v.14 no.1
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• pp.12-21
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• 2014

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.45-48
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• 2002

This paper discusses the surface roughness of negative chemically amplified resists, SAL601 exposed by I-beam direct writing. system. Surface roughness, as measured by atomic force microscopy, have been simulated and compared to experimental results. Molecular-scale simulator predicts the roughness dependence on material properties and process conditions. A chemical amplification is made to occur in the resists during PEB process. Monte-Carlo and exposure simulations are used as the same program as before. However, molecular-scale PEB simulation has been remodeled using a two-dimensional molecular lattice representation of the polymer matrix. Changes in surface roughness are shown to correlate with the dose of exposure and tile baking time of PEB process. The result of simulation has a similar tendency with that of experiment.

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.193-201
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• 2009

Structural design of most nonprismatic Pre-Engineered Building Systems (PEBS) is performed using optimizing software developed in foreign countries. In this study, a structural optimizing software for the design of 3-D structures of nonprismatic PEBS is developed according to the allowable stress design method of AISC2005 and KBC. Optimizing structural design with nonprismatic members is carried out by repeating the process of structural analysis and member design to minimize the weight of a structure. According to the optimizing design results of 2-D and 3-D structures with nonprismatic members, there are considerable steel savings in designing structures with nonprismatic H-shaped built-up sections rather than with H-shaped rolled sections. When H-shaped built-up sections were used, the weight of the structural steel was reduced when AISC2005 specification rather than AISC1898 was used in the design. It is therefore concluded that utilizing the new AISC2005 specification is safer in preventingweb buckling because the height of a member is designed to be small despite some differences depending on the structural type.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.10
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• pp.23-30
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• 1999

We experimented on the sub 50nm patterning using E-beam lithography system. SAL601 negative E-beam resist was used for this experiment. In order to utilize the maximum ability of E-beam system, firstly, we reduced the PR thickness to 100nm, and the field size to 200 ${um}m$. Then PEB (Post Expose Bake) time/temperature, which is one of the very important factors when SAL601 is used, were reduced for minimum line width. In addition, digitizing is optimized for better results. Quantum wire and quantum dot which can be used for nanoscale memory device, such as single electron memory device, are fabricated using these developed lithography techniques.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3619-3626
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• 2015

The coal shed at thermal power plant(T.P.P) is the biggest building on size among nuclear, coal and other power plant industry buildings. This the coal shed of indoor type is mass volume, the size of 6 soccer fields and 73 meter in height. Structural and functional elements take priority over aesthetic factors. The shed is built to make mighty space for structural safety and functional store by using the concrete, $75,000m^3$ on the total of central retaining wall and sub buttress, and the steel frame used by 11,744-ton P.E.B. system. The design requirement on its wall and frame, P.E.B. system's feature, and specific data of main process followed by construction are inquired. The aim of this study is to suggest the design requirement and guide for the indoor type of the coal shed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.536-538
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• 2015

전기 에너지가 우리 생활에 유용하게 사용되는 부분이 정말 많다. 최근에는 자전거 열풍이 불면서 덩달아 전동 자전거 업계에도 호황이 일고 있는데, 21C 기후 변화와 환경오염, 교통체증 등의 문제해결을 위한 저탄소 녹색성장의 인식 전환으로 전동 자전거 이용이 늘어나고 있다. 이는 전동 자전거도 전기 에너지가 사용되고 있다 점이다. 하지만 이런 장점을 가지고 있는 전동 자전거를 많은 사람들이 구입하지 못하는 이유가 있다. 대부분의 이유가 '집에 자전거 1대씩 가지고 있는데, 굳이 비싼 돈을 주고 전동 자전거를 구입해야하나?' 라는 생각을 가지게 된다. 또 다른 이유로는 기존의 전동 자전거가 탈 부착 형식이 아닌 일체형으로 나오기 때문에 다른 신제품의 전동 자전거가 나온다면 기존의 전동 자전거의 부품을 사용하지 못 하고 새로운 자전거를 사야 한다는 단점 때문이다. 따라서 본 논문에서는 탈 부착이 가능한 전기 자전거 시스템을 구현하고자 한다.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.158-158
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• 2006

The correlation between liquid-liquid phase separation (LLPS) and crystallization at several compositions in statistical copolymer blends of poly (ethylene-co-hexene) (PEH) and poly (ethylene-co-butene) (PEB) has been examined. In this case, the LLPS is coupled with the other ordering process, i.e. crystallization. The overwhelming change in the crystallization kinetics due to the composition fluctuation caused by the spontaneous spinodal LLPS is observed. This coupling mechanism suggests a new mechanism in the nucleation-crystallization process.

• Journal of Korean Society of Steel Construction
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• v.24 no.4
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• pp.461-468
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• 2012

P.E.B (Pre-Engineering Building) system means an economical system, which designs and uses optimal section proportion of tapered members according to the magnitude of bending moment. However, it is hard to adjust the friction type bolted joint in the joint of tapered member in the P.E.B system. End-plate connection is mainly used in this system due to that difficulty. Because P.E.B system has end-plate vertical defacts by heat welding deformation, a gap between end-plates and rafter or rib can be observed. In this study, an examination of construction stability was throughly performed and analyzed by the investigation of permissible internal force of bolts in end-plate connections under the bending moment using the end-plate's initial connection-defect (gap).