• Journal of the Microelectronics and Packaging Society
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• v.25 no.1
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• pp.1-10
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• 2018

Recently, there has been rapid development in the field of flexible electronic devices, such as organic light emitting diodes (OLEDs), organic solar cells and flexible sensors. Encapsulation process is added to protect the flexible electronic devices from exposure to oxygen and moisture in the air. Using numerical simulation, we investigated the effects of the encapsulation layer on mechanical stability of the silicon chip, especially the fracture performance of center crack in multi-layer package for various loading condition. The multi-layer package is categorized in two type - a wide chip model in which the chip has a large width and encapsulation layer covers only the chip, and a narrow chip model in which the chip covers both the substrate and the chip with smaller width than the substrate. In the wide chip model where the external load acts directly on the chip, the encapsulation layer with high stiffness enhanced the crack resistance of the film chip as the thickness of the encapsulation layer increased regardless of loading conditions. In contrast, the encapsulation layer with high stiffness reduced the crack resistance of the film chip in the narrow chip model for the case of external tensile strain loading. This is because the external load is transferred to the chip through the encapsulation layer and the small load acts on the chip for the weak encapsulation layer in the narrow chip model. When the bending moment acts on the narrow model, thin encapsulation layer and thick encapsulation layer show the opposite results since the neutral axis is moving toward the chip with a crack and load acting on chip decreases consequently as the thickness of encapsulation layer increases. The present study is expected to provide practical design guidance to enhance the durability and fracture performance of the silicon chip in the multilayer package with encapsulation layer.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.2
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• pp.79-87
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• 2017

GenesWell$^{TM}$ BCT is a 12-gene test suggesting the prognostic risk score (BCT Score) for distant metastasis within the first 10 years in early breast cancer patients with hormone receptor-positive, HER2-negative, and pN0~1 tumors. In this study, we validated the analytical performance of GenesWell$^{TM}$ BCT. Gene expression values were measured by a one-step, real-time qPCR, using RNA extracted from FFPE specimens of early breast cancer patients. Limit of Blank, Limit of Detection, and dynamic range for each of the 12 genes were assessed by serially diluted RNA pools. The analytical precision and specificity were evaluated by three different RNA samples representing low risk group, high risk group, and near-cutoff group in accordance with their BCT Scores. GenesWell$^{TM}$ BCT could detect gene expression of each of the 12 genes from less than $1ng/{\mu}L$ of RNA. Repeatability and reproducibility across multiple testing sites resulted in 100% and 98.3% consistencies of risk classification, respectively. Moreover, it was confirmed that the potential interference substances does not affect the risk classification of the test. The findings demonstrate that GenesWell$^{TM}$ BCT have high analytical performance with over 95% consistency for risk classification.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.903-909
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• 2017

This study was conducted to develop Helianthus tuberosus (HT) juice mixed with dried bitter melon juice and assess its hypoglycemic effect in streptozotocin (STZ)-induced diabetic rats. HT juice mixed with 5.0% dried bitter melon juice was used in this study. Male Sprague-Dawley rats were divided into four groups (eight rats per group) and drunk each sample for 4 weeks: normal water [normal control (NC) group], STZ+normal water (STZ group), STZ+HT juice (HT group), STZ+HT juice mixed with 2.5% bitter melon juice (HT2.5 group), and STZ+HT juice mixed with 5.0% bitter melon juice (HT5.0 group). HT juice was diluted to 25% in distilled water and supplied to rats. Food intake, body weight gain, and food efficiency ratio were lower in the STZ group than in the NC group. HT, HT2.5, and HT5.0 groups showed higher parameters than the STZ groups. Water intakes were higher in the STZ group than in the NC group. After 3 weeks, HT, HT2.5, and HT5.0 groups showed lower parameters than the STZ group. After 1 week, blood glucose level of the STZ group ($476.7{\pm}22.8mg/dL$) was significantly higher than those of the HT group ($376.3{\pm}25.8mg/dL$), HT2.5 group ($405.2{\pm}35.1mg/dL$), and HT5.0 group ($342.8{\pm}29.7mg/dL$). After 4 weeks, blood glucose level of the STZ group were significantly higher than those of the HT, HT2.5, and HT5.0 group. Serum insulin levels of the HT group ($3.13{\pm}0.32ng/mL$), HT2.5 group ($3.40{\pm}0.23ng/mL$), and HT5.0 group ($3.48{\pm}0.43ng/mL$) were higher than that of the STZ group ($2.72{\pm}0.53ng/mL$). These results indicate that H. tuberosus juice mixed with dried bitter melon juice helps prevent or attenuate progression of diabetes in rats with STZ-induced diabetes.

• Journal of the Korean earth science society
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• v.37 no.4
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• pp.218-229
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• 2016

The bedform stability diagram indicates the shape and size of bedforms that will occur to a given grain size and flow velocity. The diagram has been constructed from experimental data which have been mostly acquired by flume experiments. Generally, the flume experiments have been performed on well sorted sediments with unimodal grain size distribution, in order to understand relationship between grain size and flow velocity. According to the diagram, a ripple structure initiates to be formed from lower flow regime flat bed, as the flow velocity increases on the surface of fine-sand or medium-sand sediments. This study aims to verify that the experimental result of bedform stability diagram will be reproduced in our flume experimental systems, and also to confirm that the result is consistent not only on well-sorted sand sediments but also on poorly-sorted sand sediments with bimodal grain size distribution. The experimental results in this study show that initiation of 2D or 3D ripple structure on poorly-sorted sand sediments requires higher flow velocity and shear stress than those for initiation of the structure on well-sorted sand sediments. In general, carbonate sediments are characterized by poor sorting due to inactive hydraulic sorting and bimodal grain size distribution with allochems and matrices. The results suggest that the carbonate depositional system possibly need a higher flow velocity for initial formation of 2D or 3D bedform structures. The reason might be the fact that pulling off and lifting of a grain in poorly sorted sediments require more energy due to sorting, friction, stabilization, armour effects, and their complex interaction. This preliminary study warrants additional experiments under various conditions and more accurate analysis on the relationship between formation of bedforms and grain size distribution.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.56-62
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• 2015

Various pretreatment methods were evaluated to prevent tissue softening of heated onion. Changes in onion tissue firmness during heating were explained by 3-mechanism model consisting of texture hardening at low temperature ($60-80^{\circ}C$) and substrate softening at high temperature. Preheating of onion in a $Ca^{2+}$-containing solution significantly improved its texture after high-temperature heating. The improvement of firmness by preheating at low temperature was related to the formation of strong cross-linking between carboxyl groups and $Ca^{2+}$ by the action of pectin methylesterase in onion. The highest firmness was obtained by pre-heating at $70^{\circ}C$ for 120 min in 0.5% calcium solution. This result was supported by chemical analysis showing that the amount of bound calcium was the highest at $70^{\circ}C$. Further investigation should be carried out to establish the optimal conditions to prevent the softening of various vegetables.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.87-101
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• 2017

The analysis was carried out with meta-analysis on master's and doctoral dissertations, and academic journals that analyzed the effects of STEAM education between 2012 and 2015. From the total number of 75 dissertations and articles analyzed, 183 different effect sizes were calculated. The analysis was done to find out the kinds of differences that would be created according to the effect size of creativity, problem-solving ability, and researcher, target area, student division research design type, and level of schools. The total effect size of creativity scored 0.776, and demonstrated satisfaction in symmetry of funnel plot, with no publication biases. The fail-safe N scored 780, and since the number is smaller than 8,945, the results of this research has credibility. Furthermore, problem-solving ability shows intermediate level of effect size with a score of 0.584. It also showed satisfaction in symmetry with funnel plot, with no publication bias. With the different research methods of the sub-factors of creativity, fluency scored the highest with 0.929, flexibility with 0.881, originality with 0.838, sophistication with 0.653, abstractness with title 0.705, and resistance to termination, 0.527. This study finds its significance in the demonstration of average effect size of STEAM education through meta-analysis. According to research results, the effects of inclusive education could be determined, yet the specific effect cause or learning principles were difficult to find. It was found that the effects of STEAM education do not rise or fall depending on school age, and demonstrated differences in creativity according to the research methods or the researchers.

• Journal of Life Science
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• v.28 no.9
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• pp.1056-1061
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• 2018

This article reports an agar-degrading marine bacterium and characterizes its agarase. The agar-degrading marine bacterium, KC-1, was isolated from seawater on the shores of Sacheon, in Gyeongnam province, Korea, using Marine Broth 2216 agar medium. To identify the agar-degrading bacterium as Agarivorans sp. KC-1, phylogenetic analysis based on the 16S rRNA gene sequence was used. An extracellular agarase was prepared from a culture medium of Agarivorans sp. KC-1, and used for the characterization of enzyme. The relative activities at 20, 30, 40, 50, 60, and $70^{\circ}C$ were 65, 91, 96, 100, 77, and 35%, respectively. The relative activities at pH 5, 6, 7, and 8 were 93, 100, 87, and 82%, respectively. The extracellular agarase showed maximum activity (254 units/l) at pH 6.0 and $50^{\circ}C$ in 20 mM of Tris-HCl buffer. The agarase activity was maintained at 90% or more until 2 hr exposure at $20^{\circ}C$, $30^{\circ}C$ and $40^{\circ}C$, but it was found that the activity decreased sharply from $60^{\circ}C$. A zymogram analysis showed that Agarivorans sp. KC-1 produced 3 agar-degrading enzymes that had molecular weights of 130, 80, and 69 kDa. A thin layer chromatography analysis suggested that Agarivorans sp. KC-1 produced extracellular ${\beta}$-agarases as it hydrolyzed agarose to produce neoagarooligosaccharides, including neoagarohexaose (21.6%), neoagarotetraose (32.2%), and neoagarobiose (46.2%). These results suggest that Agarivorans sp. KC-1 and its thermotolerant ${\beta}$-agarase would be useful for the production of neoagarooligosaccharides that inhibit bacterial growth and delay starch degradation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1374-1387
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• 2015

The purpose of this paper was to investigate the operational status of youth facilities as well as the degree of students' satisfaction with menus served at youth facilities. The survey was conducted from July 9 to July 31, 2013 using questionnaires. The responses of 55 youth facilities and 249 students who had experienced foodservice at youth facilities were analyzed, utilizing the SPSS V20.0 program. The results on management status of youth facilities were as follows: 41.8% of youth facilities were operated for over 10 years, and 45.5% of facilities served meals for 100 to 200 students per day on average. Meal costs were 4,450 won on average, and food costs accounted for 46.8% of average meal costs. Exactly 78.2% of facilities preserved storage type meals at a temperature under -18 degrees Celsius for more than 144 hours, as the 'Food Sanitation Act' stated. Exactly 12.7% of facilities did not hire professional dietitians and had unsupervised foodservice management. Among 19 kitchen equipments surveyed in this research, Combi steamer was the least frequent at youth facilities. According to the results, most students (38.7%) ate leftovers since the food was not tasty. Overall foodservice satisfaction was on average 3.45 points, and the four factors 'dining room sanitation' (P<0.05), 'food taste' (P<0.01), 'serving various desserts' (P<0.01) and 'temperature of dining room' (P<0.05), significantly affected overall satisfaction. As food taste was critical for customer satisfaction, it is important for each dietitian to consider customers' preferences and develop recipes and menus. Further, detailed regulation and precise guidelines for youth facility foodservice are required to enhance students' foodservice satisfaction and serve nutritionally balanced menus in a hygienic manner.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.460-467
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• 2009

This research was conducted for the purpose of investigating the influence substrates addition such as germanium or Granite porphyry gravel have on the growth of foliage, on the inorganic compositions of leaves as well as on root activity, in order to discover effective means of introducing plants to the indoors. Syngonium podophyllum, Dracaena sanderiana, Epipremnum aureum and Hedera helix were used as study subjects to which soil (mixed top-soil: Sunshine Mix No. 2, USA), tap water, tap water with germanium (300g), tap water with Granite porphyry gravel (300g) were added respectively and formulated. Studies on growth variations according to substrates addition indicate that growth of Syngonium podophyllum was most sluggish under tap water only treatment. Plant growth was most active under geranium-gravel treatment. In the case of Dracaena sanderiana, treatment of substrates addition had no meaningful influence on plant growth. However, the growth of Epipremnum aureum and Hedera helix was also shown to be most active under geranium-gravel treatment. Geranium-gravel treatment was shown to be particularly beneficial for root length, number of roots and dry weight. Root activity was analyzed on ten day intervals and there was discernable difference in the root activity of all the plants according to the varying treatments. In the case of the Syngonium podophyllum, the root activity was sluggish in all three types of treatment on the 10th day but improved gradually. On the 30th to the 50th day of the experiment, the root activity was found to be best under the Granite porphyry gravel treatment. In the case of the Dracaena sanderiana, the root activity was most active under the geranium-gravel treatment from the 10th to the 40th day but deteriorated from the 50th day. However, there was no significant different in all three treatments from the 60th day onwards. Analysis of the inorganic components of the leaves indicates that, while Ca and Mg were higher in the geranium than in the Granite porphyry gravel, they do not directly influence the content of inorganic components in the leaves. The results indicate that Epipremnum aureum and Hedera helix grow better under hydro-culture than when grown in soil and growth under hydro-culture is shown to increase when germanium is added to tap water.

• Journal of Global Scholars of Marketing Science
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• v.19 no.1
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• pp.9-21
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• 2009

Recently, the researches to explain Switching Behavior through Theory of Planned Behavior have been discovered. Many researches say that System factors of mobile telecommunication service(MTS) is positively associated with Switching Intention. But There is no difference of system factors between mobile telecommunication services because of IT technique Development. Thus, this study investigated whether switching cost and alternative's attractiveness influence switching intention concerning mobile telecommunication service by adopting Theory of Planned Behavior (TPB) as an underlying theoretical premise. The study also attempted to determine the moderating effects of personal innovativeness on switching intention. For these purposes the author has developed several hypotheses as follows: H-1. The switching cost of different MTS is associated with the attitude of MTS which is using. H-2. The switching cost of different MTS is associated with the subjective norm of MTS which is using. H-3. The switching cost of different MTS is associated with the perceived behavior control of MTS which is using. H-4. The alternative's attractiveness of different MTS is associated with the attitude of MTS which is using. H-5. The alternative's attractiveness of different MTS is associated with the subjective norm of MTS which is using. H-6. The alternative's attractiveness of different MTS is associated with the perceived behavior control of MTS which is using. H-7. The switching cost of different MTS is associated with the switching intention. H-8. The alternative's attractiveness of different MTS is associated with the switching intention. H-9. The attitude of MTS is associated with the switching intention. H-10. The subjective norm of MTS is associated with the switching intention. H-11. The perceived behavior control of MTS is associated with the switching intention. H-12. The personal innovativeness has been a moderating effects to switching intention. Data has been collected from 403 respondents for this study using a questionnaire method. The survey for the actual analysis of the research was done and analyzed with the customers who have an experience of using Mobile telecommunication service and the samples were selected among the middle and high school students who live in Seoul area, the university students who live in Seoul, Gyeonggi and Chungcheng Provinces, and the ordinary workers who are working in Seoul and Gyeonggi Province. The survey was done for 23 days from March 28, 2008 through April 12, 2008. The positive analysis was done with SPSS 12.0K statistics package and visual PLS program using the analysis techniques of frequency analysis, reliability analysis, correlation analysis and factor analysis. In addition, structural equation modeling was conducted using AMOS 5.0. The data was analyzed by frequency analysis using SPSS 12.0 and structural equation modeling using AMOS 5.0. The result of the overall model analysis is as follows: Chi-Square=378.306, d.f.=107, p-value=0.0, GFI=.904, AGFI= 0.863, IFI= 0.939, NFI= 0.917, RMSEA= 0.079, TLI= 0.922. The results of the overall model analysis were coherent. The following study results were revealed: First, switching cost was related positively to attitude, subjective norm and perceived behavior control, three components of TPB. Second, alternative's attractiveness was related negatively to subjective norm but positively to perceived behavior control. Third, switching cost and attitude was related negatively to switching intention, while perceived behavior control was related positively to switching intention. Finally, the study found the moderating effects of personal innovativeness on switching intention. Based on the results, the study offers marketing strategic implications for mobile telecommunication service industry.