• 보존과학연구
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• s.25
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• pp.5-29
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• 2004

This research carried out ancient technique and composition of the relics recovered from the octagonal nine-storied pagoda of Woljeongsa temple using the scientific methods and obtained the following results. Firstly, The silver sarira inner case is consists of Ag, its materials comes out near 98wt%and comparing with the relics of Hwangnamdaechong, the contents of Ag and Ni are almost same with it. Secondly, The bronze sarira outer case, its contents of Cu is almost same with pure copper of which average is 99.7wt%. So, it should be named the copper sarira outer caserather than the bronze sarira outer case that has been called. Thirdly, The bronze mirror, though the contents of tin and lead are less than other contents which have been studied, they tend to have white color so they need to be made a close study. Especially, Because cultural property of nondestructive surface analytic method is not analyzed by the analysis of cross section and the moisten analysis, it may be occurred analytical errors by other factors.

• Journal of Advanced Marine Engineering and Technology
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• v.9 no.1
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• pp.74-88
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• 1985

The wear becomes the most complicated cause of making various machineries short lives. In the studies by many scholors so far, the accurate and perfect methods to eliminate it completely are not found yet owing to many affected factors. On this view point of Depositional Wear, the wear test with seven different specimens from the part of frequent usage of which are carbon steel, nickel, copper, aluminum, zinc, lead and tin was attempted to make clear the relation between the wear of different metals and their melting point, crystal structure, sliding speed, load and lattice factors. The results of this study are summerized as follows; 1) Worn amount of each metal is maximum when each metal is same quality. 2) The easier becomes the the formation of solid solution in the course of friction proceeding, the more it results in worn amount of each metal. 3) The samer is each metal in crystal structure as well as lattice factor, the more it results in worn amount of each metal. These results might be of use in designing machineries, selecting materials and operating machineries.

• Journal of environmental and Sanitary engineering
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• v.19 no.1
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• pp.42-49
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• 2004

The study was carried out in order to improve the quality of fermented soybean, that is, Doenjang with strain ,mold and bactea, added mulberry leaves powder were investigated and analyzed as follows. 1. The water content of samples was 38.51-50.10%, pH value 5.44-6.21 and total acidity, 2.42-3.13 2. The reducing sugar of content for samples was 7.01-7.24% on contrast mulberry added sample was 8.34-12.11%, Amino-N as contrast 5.96-7.63% mulberry added, 8.34-12.11% 3. In sensory evaluation test, excellent results was 2% added sample than others. 4. The heaby metals analyzed form samples cans, iron, tin and lead content of samples were 5.63-6.03 ppm, 31.70-35.53 ppm and trace.

• Journal of environmental and Sanitary engineering
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• v.22 no.1 s.63
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• pp.37-47
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• 2007

In order to improve the Quality of fermented soybean Doenjang was investigated. The samples were prepared and fermented by the koji made with A. oryzae, B. subtilis and B. natto strains, that the product added green tea powder with sanitary canned food. 1. The water content of sample was 50.30-42.14%, pH value 6.03-5.52 and total acidity, 3.01-3.87. 2. The reducing sugar content for samples was 9.35-7.81%, Amino-N, 7.96-9.21%. 3. In the sensory evaluation test, the good sensory qualify that was S-2 sample than to S-1 and S-3. 4. The heavy metals analyzed from sample cans, tin, iron and lead content were 27.31-29.04 ppm, 5.32-5.91 ppm and trace amount.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.184-186
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• 2006

Sn-3Ag-0.5Cu is one of candidate as an alternative approach to conventional lead-tin solder. In order to evaluate that creep characteristic of QFP, we used Sn-3Ag-0.5Cu where the operating temperature is $100^{\circ}C$. The specimens were loaded to failure at average pull strength in the range of 20% to 25%, X-ray machine is used to eliminate effect of void. In this paper, relation of time-displacement and steady state creep rate was studied, and used to analyze the experimental result.

• Structural Engineering and Mechanics
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• v.6 no.8
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• pp.857-870
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• 1998

This paper deals with a special class of inverse problems in discrete structural plasticity involving the identification of elastic limits and hardening moduli on the basis of information on displacements. The governing equations lead naturally to a special and challenging optimization problem known as a Mathematical Program with Equilibrium Constraints (MPEC), a key feature of which is the orthogonality of two sign-constrained vectors or so-called "complementarity" condition. We investigate numerically the application of two simple algorithms, both based on the use of the general purpose nonlinear programming code CONOPT accessed via the GAMS modeling language, for solving the suitably reformulated problem. Application is illustrated by means of two numerical examples.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1277-1282
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• 2008

Recently LCD panels have becom very important components for portable electronics. In the high density interconnection material, ACF's are used to connect the outer lead of the tape automated bonding to the transparent indium tin oxide electrodes of the LCD panel. ACF consists of an adhesive polymer matrix and randomly dispersed conductive balls. In this study, we analyzed Failure Mode / Mechanism of ACF which is identified Conductive ball Corrsion, Delamination, Crack and Polymer Expansion / Swelling. In ALT(Accelerated Life Test), we select primary stress factors as temperature and humidity. As time passes by, an increase of connection resistance was observed. In conclusion, we have found that high temperature / humidity affects the adhesion.

• Journal of environmental and Sanitary engineering
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• v.17 no.3
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• pp.14-20
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• 2002

In order to improve the quality and sensory evaluation of Fermented Soybean(Chungkugjang meju) were investigated. The samples were prepared and fermented by the inoculation of Bacillus strains (B. subtilis, number 1, B. natto, number 2) that the product made With sanitary canned food. 1. The water content of samples was 46.75~50.60%, pH 5.35~6.95 and total acidity 3.26~3.62. 2. The reducing sugar of content for sample was 9.49~10.05%, Amino-N, 67~396mg% and the activity of protease was 0.36~1.49unit/g. 3. The heavy metals analyzed from sample cans, iron, tin and lead content of sample were 5.32~5.84ppm, 27.31~29.04ppm and 0.019~0.021ppm. 4. Therefore, results that Chungkugjang-meju manufactured from B. natto starter induced better product Quality and sensory test than that of the B. subtilis strain.

• Journal of the Korean institute of surface engineering
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• v.36 no.2
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• pp.168-175
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• 2003

The purpose of solder plating on chip external electrode is to provide a proper solderability to chips on PCB's. The quantitative or qualitative analysis of solderability has been performed by destructive methods, reflow or flow. Evidently, the solderability tends to depend on the grain structure which is varied with additives. Research on the feasibility of employing electrochemical techniques to characterize the solderability of electroplated tin - lead, with respect to the additives, was non destructively performed. The deposit morphology and the polarization behavior of electrolytes containing proprietary additives were evaluated to investigate the soldering degradation. The plated panels from synthetic electrolyte were analyzed according to % Sn, plating thickness, deposit appearance, grain structure, solderability and cyclic voltammetry.

• 보존과학연구
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• s.23
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• pp.149-162
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• 2002

Gilt bronze locks(Treasure No. 1141) excavated from Hancheonsa temple are artifacts of Goryeo Dynasty. The locks underwent a conservation process from October 2001 to July 2002. The process included cleaning and the application of corrosion inhibitors, Benzotriazolesolution, as well as reinforcement treatment with Paraloid NAD-10 solution,an acrylic resin. Non-destructive XRF analysis unveil that the artifacts are made of an alloy of copper(Cu), tin(Sn) and lead(Pb), but the gilt layer is too thin to analyze the purity of the gold or the exact production method. Gilt bronze locks are important materials because they preserve all the structures of locks in Goryeo Dynasty to the smallest detail. The surface pattern is revealed through the conservation process and components of the alloy through material analysis.