• Journal of Welding and Joining
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• v.30 no.5
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• pp.64-69
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• 2012

Sn-Bi eutectic alloy has been widely used as one of the key solder materials for step soldering at low temperature. The Sn-58Bi solder paste containing chloride flux was adopted to compare with that using the chloride-free flux. The paste was applied on the electroless nickel-immersion gold (ENIG) surface finish by stencil printing, and the reflow process was then performed at $170^{\circ}C$ for 10 min. After reflow, the solder joints were aged at $125^{\circ}C$ for 100, 200, 300, 500 and 1000 h in an oven. The interfacial microstructures were obtained by using scanning electron microscopy (SEM), and the composition of intermetallic compounds (IMCs) was analyzed using energy dispersive spectrometer (EDS). Two different IMC layers, consisting of $Ni_3Sn_4$ and relatively very thin Sn-Bi-Ni-Au were formed at the solder/surface finish interface, and their thickness increased with increasing aging time. The wettability of solder joints was investigated by wetting balance test. The mechanical property of each aging solder joint was evaluated by the ball shear test in accordance with JEDEC standard (JESD22-B117A). The results show that the highest shear force was measured when the aging time was 100 h, and the fracture mode changed from ductile fracture to brittle fracture with increasing aging time. On the other hand, the chloride flux in the solder paste did not affect the shear force and fracture mode of the solder joints.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.125-134
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• 2012

In this paper, we propose a method to analyze M:N corresponding relations in semantic matching, especially focusing on feature class matching. Similarities between any class pairs are measured by spatial objects which coexist in the class pairs, and corresponding classes are obtained by clustering with these pairwise similarities. We applied a graph embedding method, which constructs a global configuration of each class in a low-dimensional Euclidean space while preserving the above pairwise similarities, so that the distances between the embedded classes are proportional to the overall degree of similarity on the edge paths in the graph. Thus, the clustering problem could be solved by employing a general clustering algorithm with the embedded coordinates. We applied the proposed method to polygon object layers in a topographic map and land parcel categories in a cadastral map of Suwon area and evaluated the results. F-measures of the detected class pairs were analyzed to validate the results. And some class pairs which would not detected by analysis on nominal class names were detected by the proposed method.

• Journal of Internet Computing and Services
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• v.18 no.6
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• pp.137-144
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• 2017

A variety of customized marketing strategies are being implemented in the telecommunications market, including the offering of gifts to consumers, as competition in the market is being restructured with the focus on bundled products. However, the Korea Communications Commission (KCC) has recently imposed fines for user discrimination on telecommunication carriers whose marketing strategies have included the award of excessive prizes. In that regard, various issues related to the suitability and appropriate limit of the current gift regulation in the telecommunications market have been raised. Since the Fair Trade Commission, which had a similar scheme to that of the KCC, abolished the regulation on gifts in July 2016, disputes have arisen as to whether the current regulation on gifts is practically effective from the perspective of consumer benefit. In other words, discussions on the rationality of the theoretical and empirical grounds for the regulation on gifts only in the telecommunication market but not in other commodities markets have begun. As such, this study aims to empirically analyze the suitability of the current regulation on gifts in the domestic telecommunications market under the new competitive environment centered on bundled products, and to seek the rational improvement of, and infer the implications for, the regulation on gifts in the telecommunications market based on the results of the analysis.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.278-285
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• 2016

This study used response surface methodology (RSM) in an effort to optimize the ultrasoundassisted extraction condition of Camellia sinensis L. and Artemisia argyi mixture in order to increase extraction yield in the extract. The effects of three independent variables, $X_1$ (Mixture ratio, 60-80%), $X_2$ (Ratio of water to raw material, 20~100 mL/g), and $X_3$ (Extraction time, 25-145 min), were investigated at three levels using Box-Behnken design (BBD) to obtain the highest extraction efficiency. Y (Extraction yield) was chosen as dependent variable. Our result showed that the coefficient of determination ($R^2$) of the model was 0.9747, with significant at the level of p < 0.002. Furthermore, the predicted values of each variable were similar to the actual values. The optimum extraction conditions were as follows: mixture ratio of 85.86%, ratio of water to raw material of 92.73 mL/g, and extraction time of 56.52 min. At these conditions, predicted extraction yield was 30.03%. The analysis of variance (ANOVA) indicated a high goodness of model fit and the success of the RSM method for optimizing extraction conditions of Camellia sinensis L. and Artemisia argyi mixture.

• Journal of the Korean Magnetics Society
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• v.25 no.6
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• pp.208-218
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• 2015

Recently, radiation therapy is used in the CT existing conventional two-dimensional radiation image, and set the size and location of the tumor in a manner that the image is going to change the treatment plan. After using the simulation using CT, radiation therapy it is four-dimensional or three-dimensional treatment made possible. and radiation therapy became the more effective ever before. High technology radiation therapy such as the treatment of SRS,IMRT, IGRT, SBRT, is a need to try contemplating the possibility to apply appropriate analysis and situation, so it has its own characteristics. and then it is believed that it is necessary to analyze and try it worries the proper applicability of the situation. The configuration of the various treatment that is applicable in many hospitals is necessary to try to determine how to practically apply the patients. Critical organs surrounding tumor give a small dose to avoid side effects and then the tumor has the therapeutic effect by providing a larger dose than before the radiation treatment.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.355-364
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• 2008

Emerald deposit located on Itabira, Brazil is one of the major one in the world. We applied three different analytical approaches on Itabira emerald samples, (1) perpendicular to the c-axis, (2) parallel to the c-axis, (3) emerald pallet mixed with KBr, using Fourier Transform Infrared (FTIR) spectroscopy, to understand and compare spectroscopic characteristics of three Itabira emerald samples. Occurrence of $5,271\;cm^{-l}$ and $1,638\;cm^{-l}$ absorption peaks within $H_2O$-related range indicates that the samples belong to Type-II emerald. These emerald samples also display strong absorption peak generated from Type-IIa emerald preserving $H_2O-Na-H_2O$ sequence. $CO_2$- and Cl-related absorption peaks observed within specific range except for $H_2O$-related range. These observations and results suggest that FTIR analysis can be used for not on1y classification of emerald types, but also prediction of $Na_2O$ content within the emerald through comparison of relative peak intensity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.74-79
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• 2014

The purpose of this study was to determine the efficacy of Aster koraiensis Nakai as a natural health food source. To accomplish this, the general and antioxidative contents of A. koraiensis were measured. Total contents of carbohydrates, crude protein, crude lipid, and ash were 72.15%, 13.49%, 5.09%, and 9.27%, respectively. Caloric content of A. koraiensis was 349.70 kcal, while total dietary fiber was 49.79%. Total proteins consisted of 18 different kinds of amino acids. Contents of essential and non-essential amino acids were 4.6 and 5.5 g/100 g, respectively. Regarding mineral contents, P was the most abundant mineral, followed by K, Ca, and Na. Therefore, A. koraiensis is an alkali material. Total phenol contents of the hot water and 80% ethanolic extracts of A. koraiensis were $87.7{\pm}5.01$ and $112.4{\pm}3.41$ mg GAE/g, respectively. Total flavonoid contents of the hot water and 80% ethanolic extracts were $86.6{\pm}3.71$ and $95.1{\pm}8.00$ mg RE/g, respectively. The DPPH radical-scavenging activity and reducing power of the 80% ethanolic extract of A. koraiensis were higher than those of the water extract. Therefore, the general nutrients and antioxidant bioactive materials in A. koraiensis are potential materials for health foods.

• Culinary science and hospitality research
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• v.19 no.5
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• pp.136-145
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• 2013

Currently many studies aimed at enhancing efficacy of medicinal food on biological activity using bioconversion technology including fermentation process. In this study, the quality characteristics and antioxidative activity of fermented Crataegi fructus was investigated. The antioxidant activity of fermented Crataegi Fructus was assessed by various radical scavenging assays using DPPH (2,2-Diphenyl-1-picrylhydrazyl), FRAP (Ferric ion reducing antioxidant power), Reducing power and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)). Moisture content of fermented Crataegi Fructus was $39.3{\pm}0.06%$. Contents of crude ash, crude protein, and crude fat were $0.20{\pm}0.01$, $1.77{\pm}0.04$, and $1.40{\pm}0.59%$, respectively. Moreover, the hunter's color values of fermented Crataegi Fructus were 79.24 (lightnees), 1.58 (redness), and 31.25 (yellowness), respectively. Total phenolic contents of fermented Crataegi Fructus were $3,015{\pm}250$ GAE ${\mu}g/g$. The antioxidative activities of fermented Crataegi Fructus significantly increased in a dose dependent manner. In addition, fermented Crataegi Fructus slightly (10.4%) inhibited ${\alpha}$-glucosidase activity; however, there was no inhibitory activity against ${\alpha}$-amylase. In terms of proteolytic activity, fermented Crataegi Fructus showed a strong activity than pancreatin (used as a positive control). These results indicate that fermented Crataegi Fructus can be used as a natural resource for material aiding digestion.

• Journal of Magnetics
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• v.21 no.2
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• pp.293-297
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• 2016

For mastectomy patients, sufficient doses of radiation should be delivered to the surface of the chest wall to prevent recurrence. A bolus is used to increase the surface dose on the chest wall, whereby the surface dose is confirmed with the use of a virtual bolus during the computerized treatment-planning process. The purpose of this study is an examination of the difference between the dose of the computerized treatment plan and the dose that is measured on the bolus. Part of the left breast of an Anderson Rando phantom was removed, followed by the attainment of computed tomography (CT) images that were used as the basis for computerized treatment plans that were established with no bolus, a 3 mm-thick bolus, a 5 mm-thick bolus, and a 10 mm-thick bolus. For the computerized treatment plan, a prescribed dose regimen was dispensed daily and planning target volume (PTV) coverage was applied according to the RTOG 1304 guidelines. Using each of the established computerized treatment plans, chest-wall doses of 5 points were measured; this chest-wall dose was used as the standard for the analysis of this study, while the level of significance was set at P < 0.05. The measurement of the chest-wall dose with no bolus is 1.6 % to 10.3 % higher, and the differences of the minimum average and the maximum average of the five measurement points are -13.8 and -1.9, respectively (P < 0.05); however, when the bolus was used, the dosage was measured as 3.7 % to 9.2 % lower, and the differences of the minimum average and the maximum average are 7.4 and 9.0, -1.2 and 17.4, and 8.1 and 19.8 for 3 mm, 5 mm, and 10 mm, respectively (P < 0.05). As the thickness of the bolus is increased, the differences of the average surface dose are further increased. There are a variety of factors that affect the surface dose on the chest wall during post-mastectomy radiation therapy, for which verification is required; in particular, a consideration of the appropriate thickness and the number of uses when a bolus is used, and which has the greatest effect on the surface dose on the chest wall, is considered necessary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1408-1413
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• 2017

The aim of this study was to investigate the antioxidant activities and protective effects of hot water extract from Curcuma longa L. (CLW) on oxidative stress-induced C2C12 myoblasts. Antioxidant activities of CLW were evaluated based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities. Protective effects of CLW on oxidative stress-induced C2C12 myoblasts were determined based on cytotoxicity, $H_2O_2$ protective activity, and intracellular reactive oxygen species (ROS) level. DPPH and ABTS radical scavenging activities represented by $SC_{50}$ were $188.5{\pm}3.0{\mu}g/mL$ and $92.0{\pm}0.9{\mu}g/mL$, respectively. Using C2C12 myoblasts, CLW treatment increased cell viability against oxidative stress-induced cell death. Further, CLW treatment reduced the intracellular ROS level in cells treated with $H_2O_2$. These results suggest that CLW might have the capability to protect oxidative stress-induced C2C12 myoblasts.