• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.52-56
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• 2001

Experiments of 2 type on insulating compounds accomplished to change PVC using in URD(Underground) power cable jacketing. one was DB(Dielectric Breakdown) test on the pure base resins and the others were WVT(Water Vapor Transmission) test on the compounds which contained C/B(Carbon Black), anti-oxidant to base resin. a kind of specimens made by pressing to resin of pellet or lump form was HDPE(High Density Polyethylene), MDPE(Medium Density Polyehylene), LDPE(Low Density Polyethylene), LLDPE(Linear Low Density Polyethylene), PVC(Polyvinyl Chloride). As a results of AC DB and WVT test, we saw that strength of Insulation was HDPE> LLDPE = MDP E> LDPE and WVT ratio was HDPE

• The Transactions of the Korea Information Processing Society
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• v.1 no.2
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• pp.141-153
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• 1994

According to various information needs of end-users in information society, it brings forward a study on a database(DB) product costing method in order to activate the DB industry. The objective of this paper is to propose the DB product costing method of the DB service. The first thing classifies the elements of DB product cost accounting by the activities of the circulation system of information in the DB service. Based on the assumptions in terms of DB product cost accounting, the second is to develop its model. The last is to present the process of DB product cost accounting by applying the model to a company which provides the DB service. It is necessary to research continuously regarding the DB product costing method because its purpose is to decide a DB service charge. The right pricing decision in the DB service charge will contribute toward the growth of the DB industry acceleratedly.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.849-856
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• 2012

Chip on board type white light emitting diode on metal core printed circuit board with high thixotropy silicone is fabricated by vacuum printing encapsulation system. Encapsulant is chosen by taking into account experimental results from differential scanning calorimeter, shearing strength, and optical transmittance. We have observed that radiant flux and package efficacy are increased from 336 mW to 450 mW and from 11.9 lm/W to 36.2 lm/W as single dome diameter is varied from 2.2 mm to 2.8 mm, respectively. Double encapsulation structure with 2.8 mm of dome diameter shows further significant enhancement of radiant flux and package efficacy to 667 mW and 52.4 lm/W, which are 417 mW and 34.8 lm/W at single encapsulation structure, respectively.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.708-711
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• 2008

This study is intended to build research for ways to utilize material information in the design and working business for public works. The contents and results of this study can be classified into object-oriented DB application to bridge construction and object-oriented DB utilization of civil material information. First, application of object-oriented DB to bridge construction 1) constructs the work unit of classified work table as an object(Each object constructs material information on the statement of quantity calculation as data), 2) constructs object-oriented DB for superstructure and substructure of PSC Beam bridge, 3) leads to the research for ways to utilize materials by developing 3D bridge prototype with REVIT structure. Secondly, ways to utilize object-oriented DB for civil material information identified the possibility for utilizing it in making 2D drawings for design work, preparing materials list, analyzing structure for working businesses, selecting and purchasing materials, managing process and maintaining. It is suggested that the results of this study should be applied to all bridge constructions through test-bed and additional studies so as to secure the credibility of the results of this study.

• 기계와재료
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• v.22 no.1
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• pp.84-93
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• 2010

본 고에서는 소재분야의 기술수준을 정확히 파악하고, 앞으로 나아갈 R&D 정책방향을 설정하는 데 도움이 되도록 하기 위해 NS(National Science Indicators) DB와 Web of Science DB의 재료과학(Materials Science) 분야를 토대로 논문분석을 수행하였다. 최근 10년간(1999-2008년) 소재 분야에 대한 분석결과 양적 지표인 논문수는 연평균 12%로 지속적으로 증가하였으며, 세계순위는 1999년 9위에서 2008년 4위까지 상승하였다. 질적지표인 논문1편당 피인용횟수는 세계 평균 대비 1999년 94.7%(한국 9.35건, 세계 9.87건)에서 2008년 88.4%(한국 0.23건, 세계 0.26건)로 낮아진 것으로 나타났다. 최근 10년간 연구주체간 협력 논문수를 살펴보면 대학-대학간 이 4,337편(39.8%)으로 가장 많으며, 대학-공공연구기관간은 3,135건(28.8%), 대학-기업은 2,295건(21.1%)으로 전체의 약 90%를 차지하고 있다. 또한 해외 협력논문수는 전체 논문에서 약 26%를 차지하고 있다. 결과적으로 기초연구성과의 실용화 연계 지원책 마련, 질중심 논문평가의 강화, 국내외 협력주체간 협력 연수의 강화, 주기적 논문분석을 통한 소재 R&D 정책 수립 및 연구사업기획에의 활용강화 필요하다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.537-540
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• 2003

The importance of LCC analysis has been enlarged. Also, it would be necessary to computerize LCC analysis for accurate and logical analysis of LCC. In other papers, they showed LCC analysis model but the study of database development which could be applied in LCC analysis have been undeveloped. As a result, the final goal of this study is to develope LCC database. And this progress is devided 4 steps as design, construction, maintenance and disposal and derived the detailed cost item in the progresses. Futhermore, it would be possible to develope cost DB, fluent DB, general DB, building section DB, material DB and to propose database which would be applied in accurate and logical analysis of LCC.

• Composites Research
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• v.27 no.4
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• pp.130-134
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• 2014

The purpose of this paper is to build DB in order to Propose new constitutive equations by redefining constitutive equations for Polyurethane presented by Jeong et al. [12] based on Quasi-static test and Impact test DB of Expanded polypropylene using cylindrical specimens with 4 different densities presentsd by Kim et al. [7] for EPP foam and combining the impulse-momentum theory.

• Journal of Korean Association for Spatial Structures
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• v.10 no.2
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• pp.117-126
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• 2010

Experiment on flexural analysis of RC beams strengthened with composite material panel is presented. Recently, the strengthening of reinforced concrete structures using advanced fiber reinforced plastic (FRP) composites, and in particular the behavior of FRP-reinforced concrete structure is topic that has become very popular because of good corrosion resistance and easy for site handling due to their light weight. In this study, an efficient computational analysis using ABAQUS to predict the ultimate moment capacity of reinforced concrete beams strengthened with FRP is presented. Test parameters in this study are the shape of fiber arrangement (LT, DB, DBT) and the number of carbon fiber sheets (2ply, 3ply). When comparing with results of the analytical model, results of the experiments show similar values. Furthermore, reinforced concrete beam with FRP obtains improved effects for ultimate strength.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.52-56
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• 2001

Experiments of 2 type on insulating compounds accomplished to change PVC using in URD(Underground) power cable jacketing. one was DB (Dielectric Breakdown) test on the pure base resins and the others were WVT(Water Vapor Transmission) test on the compounds which contained C/B(Carbon Black), anti-oxidant to base resin. a kind of specimens made by pressing to resin of pellet or lump form was HDPE(High Density Polyethylene), MDPE(Medium Density Polyehylene), LDPE(Low Density Polyethylene), LLDPE(Linear Low Density Polyethylene), PVC (Polyvinyl Chloride). As a results of AC DB and WVT test, we saw that strength of Insulation was HDPE > LLDPE ≒ MDPE > LDPE and WVT ratio was HDPE < LLDPE < MDPE < LLDPE ≒ LDPE${\ll}$PVC. WVT of PVC using for jacket showed characteristic 15 times more than MDPE or LLDPE. Therefore, to development of watertightness cable, our works present need of Changing in insulating materials

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.101-108
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• 2008

This study is to examine bond strength of beam reinforced with GFRP rebar under 4-point fatigue bending test by adopting BRITISH STANDARD. The variables were made to have bonding length of 5times(5db), and 15times(15db) of the nominal diameter of GFRP rebar and were done to analyze the relationship between the bonding strength and the slip. In the result of the test, pull-out failure was dominant in the 5db specimen, patterns of the pull-out failure and concrete shear failure appeared in the 15db specimen showed only concrete shear failure at the end of bonding length. Therefore, The strain development consist of three different stage : A rapid increases form 0 to about 10% of total fatigue life. A uniform increases form 10% to about 70%~90%. Then a rapid increases until failure, if failure takes place. It seems that stress level has not influence on the secant modules of elasticity. And also according to the outcome the existing strengthening method came out to be the most superiority in S-N graphs.