• Journal of the Microelectronics and Packaging Society
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• v.18 no.2
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• pp.49-55
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• 2011

The failure of electronic instruments is mostly caused by heat and shock. This shock causes the crack initiation at the solder joint interface of PCB component which is closely related with the formation of intermetallic compound(IMC). The Ag content in Pb-free Sn-xAg-0.5Cu solder alloy used in this study was 1.0, 1.2 and 3.0 wt.%, respectively. After soldering with PCB component, isothermal aging was performed to 1000 hrs. The growth of IMC layer was observed during isothermal aging. The drop impact property of solder joint was evaluated by impact bending test method. The solder joint made with the solder containing lower Ag content showed better impact bending property compared with that with higher Ag content. On the contrary to this result, the solder joint made with solder containing higher Ag content showed better impact bending property after aging. It should be caused by the formation of fine $Ag_3Sn$, which relieved the impact. It showed consequently the different effect of fine $Ag_3Sn$ and coarse $Cu_6Sn_5$ particles formed in the IMC layer on the impact bending property.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.2
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• pp.57-62
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• 2011

The energy conversion efficiency of DSSCs (Dye-Sensitized Solar Cells) is dependent on the powder size, the structure, and the morphology of $TiO_2$ electrode. The higher efficiency is obtained with high surface area of the nanoanatase-$TiO_2$ powder adsorbed onto a lot more of the dye. Also, the enhancement of light scattering increases the efficiency with high adsorption of the dye. Powder size, crystalline phase, and shape of $TiO_2$ obtained by hydrothermal method have 15-20 nm, anatase and round. $TiO_2$ electrode has fabricated with the mixture of scattering $TiO_2$ particle with 0.4 ${\mu}m$ in nano-sized powder. Conversion efficiency of series of DSSCs was measured with volume fraction of scattering particle. Photovoltaic characteristics of DSSCs with 10% scattering particles are 3.51 mA for Jsc (short circuit current), 0.79 V for Voc(open circuit potential), filling factor 0.619 and 6.86% for efficiency. Jsc was improved by 11% and enhancement of efficiency by 0.77% compared with that of no scattering particles. The confinement of inserted light by light scattering particles has more increase of the injection of exiton(electron-hole pair) and decrease of moving path in electron. Efficiencies of DSSCs with more than 10% for scattering particles have reduced with increasing the pore in the $TiO_2$ electrode.

• Journal of Digital Contents Society
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• v.15 no.4
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• pp.513-520
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• 2014

The Smart Grid is next-generation power system materialized Convergence and Integration of power technologies and Information Technologies. And this system is the next generation power system optimizing energy efficiency via real-time information exchanges grafting the information technologies upon present power networks which are web-net. The introduction of smart grid can be embodied for latitude, distributed and cooperated network by inter-active exchange of energy information between electrical power provider and consumer previous uni-directional electrical power supplement. Therefore in this paper, we proposed Convergence technologies - Smart power grid, Smart Place, Smart Renewable and Smart Electricity Service - to make smart-grid succeed via analyzing the datum. And we scoped on Convergence and Integration technologies, which could be used for smart-power-grid that is most important factor to replace previous power industries. And we brought out the expecting industrialize timing and interesting aspects and analyzed the result with survey of professional worker from institute, research center, power plant and business of power industries. And proposed the essential policies for the government and power-control-business companies based on the datum and survey output.

• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.84-90
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• 1985

The objective of this study is to analyze the market structure and price formation status of imported log from overseas which has leadership of timber price decision mechanism in Korea. The results obtained are as follows; 1) The 53 percents of the total 134 log importing companies are the small scale companies which import less than ten thousand cubic meters per year, and are mainly aimed to do agent task of importing log. 2) The market structure of imported log formed high level 01 oligopolistic structure, but did not make excess profit of oligopoly because of excess import. 3) The bargaining power of Korea on the price decision process in the overseas log exporting market is very weak, because the market has the bilateral oligopoly structure, and the non-systematic importing behavior of Korean log importing companies make the bargaining power of Korea more weak. 4) It is analyzed that Korean domestic marketing system is comperatively simple, but reasonable marketing system is not established because of the disorder of the marketing behavior. From the results obtained above, it is proposed that the government has to establish the general institutional system to control the supply-demand and marketing problems of imported log, in order to establish the rational structure of market and price decision system of imported log.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.261-268
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• 2018

The purpose of this study was to investigate the changes of serum immunoblobulin and DHEAs when 8 weeks of combined exercise and peony intake have been held to women in their 40s and 50s. 15 participants were chosen, divided into three groups, and they had undergone combined exercise with the level of 1RM 60~70%, HRmax 60~70%, three times a week for 60 minutes each. For the proper intake, 6g of peony were warmed in a double boiler with water 107ml, and the crude liquid was ingested 100ml each by the participants, everyday before breakfast, for 8 weeks. The following conclusions were obtained through these objectives and procedures. First, the amount of immunoglobulin has increased in two groups, the 8-week combined exercise group and the group which undergone both the peony intake and the combined exercise, but did not show the significant difference(p>.05). Second, the results of DHEAs showed an increas in two groups, the 8-week combined exercise group and the group which undergone both the peony intake and the combined exercise, but did not show the significant difference(p>.05). Therefore, the consumption of peony and complex exercise in this study did not positively affect the immune function and dementia prevention.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.2
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• pp.39-46
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• 1982

A model of substrate removal by rotating discs has been developed for a better understanding of the process, and the performance of the system has been evaluated under steady and unsteady state. The model was constructed based upon mass transfer of the substrate from the bulk solution to the biofilm and a simultaneous removal of the substrate by the biomass. The model is composed of a few sets of differential equations representing mass balance within the elements of a liquid film and a biofilm, and in the bulk solution. Substrate removal efficiency of the process is largely dependent on a diffusion coefficient of the substrate within the biofilm and a maximum rate of substrate removal of the biomass. The efficiency is affected to a greater extent when the substrate concentration is low and the maximum substrate removal rate is high. The efficiency increases proportionally with increasing film depth when the biofilm is shallow, however, the rate of increase gradually decreases with an increase of the film depth. As the film reaches a limiting depth, the efficiency remains constant. Unlike the steady state, the effluent quality is affected by the tank volume under dynamic state. Increasing tank volume decreases peak concentration of the effluent under peak loading. Additional tank volume provides a buffer capacitya.gainst a peak loading and the holding tank behaves like an equalization tank.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.2
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• pp.23-38
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• 1990

In this study, decompositive optimization method of two levels was selected to optimize effectively the geometry of the truss which takes the multi-loading condition, and the allowable stress, bucking stress, displacement and natural frequency constraints into consideration. The algorithm of this study is made up of sectional optimization using the feasible direction method in level 1, and geometrical optimization employing Powell's one-direction search method which menimizes only objictive function in level 2. The results of this study acquired by beenning applied to structural model of the truss are as follows : 1. It is verified that the algorithm of this study effectively converges, independent of the initial geometry of the truss and the applied various constraints. 2. The optimum goemetry of the truss varies more considerably according to the constraints selected. 3. Under the condition of the same design, the weight of the truss can be decreased more considerably by means of optimizing even the geometry of truss than by means of optimizing the section of truss while fixing geometrical configuration of it, even though there might be a little difference according to the initial geometry of the truss and the design condition.

• Journal of Genetic Medicine
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• v.6 no.2
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• pp.146-154
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• 2009

Multiplex ligation dependent probe amplification (MLPA) is a PCR-based method to detect gene dosage. Since its introduction, MLPA has been used to test a large number of genes for major deletions or duplications. Genetic testing, as a diagnostic tool for genetic disease, has been used primarily to identify point mutations, including base substitutions and small insertions/deletions, using PCR and sequence analysis. However, it is difficult to identify large deletions or duplications using routine PCR- gel based assays, especially in heterozygotes. The MLPA is a more feasible method for identification of gene dosage than another routine PCR-based methods, and better able to detect deleterious deletions or duplications. In addition to detection of gene dosage, MLPA can be applied to identify methylation patterns of target genes, aneuploidy during prenatal diagnoses, and large deletions or duplications that may be associated with various cancers. The MLPA method offers numerous advantages, as it requires only a small amount of template DNA, is applicable to a wide variety of applications, and is high-throughput. On the other hand, this method suffers from disadvantages including the possibility of false positive results affected by template DNA quality, difficulties identifying SNPs located in probe sequences, and analytical complications in quantitative aspects.

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.696-701
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• 1996

For effective utilization of skipjack (Katsuwonus pelamis) cooking juice (SCJ), the SCJ was hydrolyzed with 0.5% neutrase at $50^{\circ}C$ for 1 hr, and the degree of hydrolysis was estimated to be 66.0% at this reaction condition. The hydrolysate was treated with charcoal and filtered under reduced pressure. The extract powder was prepared from the filtrate in a spray-dryer. The major free amino acids of the extract Powder were taurine (526.3 mg/100 g), glutamic acid (375.8 mg/100 g), phenylalanine (315.9 mg/100 g), and alanine (283.6 mg/100 g), and their content accounted for 55.4% of the total free amino acids (2,711.5 mg/100 g). Among the nucleotides and their related compounds, inosine was the major component with 76.29 mole/g. The content of betaine-N, total ceatinine-N, TMAO-N, and TMA-N were 72.2, 51.2, 10.3, and 6.9 mg/100 g, respectively. From the omission test, it was concluded that the major taste compounds of the extract powder were believed to be free amino acids such as glutamic acid and alanine. Organic acids and nucleotides and their related compounds acted an auxiliary role in the taste of the extract powder.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.1
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• pp.62-72
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• 2010

PM OLED is used in many applications as one of the display for the next generation. The most essential problems are the power dissipation and the short life time in applying PM OLED into a commercial application. Many efforts are made in developing the panel and in improving the circuit for expanding the current market wider. The life time in PM OLED is expanded by lessening the power dissipation of the circuit for the magnitude of the driving current is lowered. It is possible to minimize the power dissipation from improving the driving technology. The classical technology, Row-to-Row driving, is that row is selected one by one while applying the column current input individually. The multi-line driving is a new technology which is to select multiple rows simultaneously while applying the column current as a whole. However, the solution of the multi-line driving is NP-complete problem. The efficiency is dependant on the sort of picture and the driving condition. This paper presents the new efficient multi-line driving which is that the multiple lines are selected by applying column current together after grouping the simultaneous driving group applying the gnew efficient muthe coi-line dr coefficient. Bengrouping the several rows which has the higher coi-line dr coefficient, the more efficient driving is realized to present the high quality image and to lessen the power dissipation and to stretch the life time in the PM OLED.