• Journal of Korea Water Resources Association
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• v.39 no.3 s.164
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• pp.261-274
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• 2006

This study performs a daily long-term runoff analysis for 30 years to forecast medium- and long-term probabilistic reservoir inflows on the Soyang River basin. Snowmelt is computed by Anderson's temperature index snowmelt model and potenetial evaporation is estimated by Penman-combination method to produce input data for a rainfall-runoff model. A semi-distributed TOPMODEL which is composed of hydrologic rainfall-runoff process on the headwater-catchment scale based on the original TOPMODEL and a hydraulic flow routing model to route the catchment outflows using by kinematic wave scheme is used in this study It can be observed that the time variations of the computed snowmelt and potential evaporation are well agreed with indirect observed data such as maximum snow depth and small pan evaporation. Model parameters are calibrated with low-flow(1979), medium-flow(1999), and high-flow(1990) rainfall-runoff events. In the model evaluation, relative volumetric error and correlation coefficient between observed and computed flows are computed to 5.64% and 0.91, respectively. Also, the relative volumetric errors decrease to 17% and 4% during March and April with or without the snowmelt model. It is concluded that the semi-distributed TOPMODEL has well performance and the snowmelt effects for the long-term runoff computation are important on the study area.

• Nuclear Engineering and Technology
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• v.23 no.1
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• pp.1-11
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• 1991

The objective of this study is to investigate the effect of weld line on the mechanical strengths and the process of weld line elimination in the Zircaloy-4 resistance upset welding for the fabrication of heavy water reactor fuel rods. The weld current and the amount of upset increased linearly with the main heat, in which two relations between them were derived. It was found that the threshold to obtain sound weld was 50% of main heat in terms of weld upset size, mechanical strengths and weld line elimination. The weld microstructure of resistance upset welds of Zircaloy-4 comprsied basketweave, Widmanstatten and martensite respectively by changing the main heats. Dimples on uniaxially fractured surface at weld line in the Zr-4 welds were larger and deeper compared with those on biaxially fractured surface. It was also found that the process of the weld line elimination in the resistance upset weld of Zircaloy-4 could be divided into three stages in terms of the presence of many pores, their shrinkage and elimination, and the shrinkage of the original weld interface with increasing weld currents.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.1
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• pp.93-104
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• 2019

This study examined the relationship between the number of medical technologists and the medical test count. Data was obtained from 441 medical technologists in a hospital through a self-reported questionnaire. The Pearson correlation test, student's t-test, ANOVA or descriptive statistics were performed for data analysis. The distribution of medical technologist according to the size of hospitals was small 5.8, medium 14.9, large 25.8, and super 45.4. The analysis demonstrated a relationship between the number of medical technologists and the number of medical tests in the field, number of clinical tests per MT, and number of optimal medical test per MT according to the hospital size (P<0.001). The average time for quality control by the department at a higher hospital was less than two hours. In terms of the satisfaction of salary, work environment, test accomplishment, and welfare service, the dissatisfaction of medical technologists in small and medium hospitals was higher than those in large and super hospitals. Overall, a focus on intensifying systemic supplementation and improving the condition of medical technologists is needed to provide reliable data for medical examinations in medical areas.

• The Journal of Korean Association of Computer Education
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• v.22 no.5
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• pp.51-65
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• 2019

This study aims to provide educational implications for more strategic online software education by the types of online learning according to learners' self-regulated learning characteristics in the online software education environment and examining the characteristics of each type. For this, variables related to self-regulated learning characteristic were extracted from the log data of 809 students participating in the online software learning program of K University, and then analyzed using hierarchical cluster analysis. Based on hierarchical cluster analysis learner clusters according to the characteristics of self-regulated learning were derived and the differences between learners' learning characteristics and learning results according to cluster types were examined. As a result, the types of self-regulated learning of online software learners were classified as 'high level self-regulated learning type (group 1)', 'medium level self-regulated learning type (group 2)', and 'low level self-regulated learning type (group 3)'. The achievement level was found to be highest in 'high-level self-regulated learning type (group 1)' and 'low-level self-regulated learning type (group 3)' was the lowest. Based on these results, the implications for effective online software education were suggested.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.121-129
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• 2021

In this study, we try to minimize the tariff risk by constructing a hazardous cargo screening model by applying Association Rule Mining, one of the data mining techniques. For this, the risk level between supply chains is calculated using the Apriori Algorithm, which is an association analysis algorithm, using the big data of the import declaration form of the Korea Customs Service(KCS). We perform data preprocessing and association rule mining to generate a model to be used in screening the supply chain. In the preprocessing process, we extract the attributes required for rule generation from the import declaration data after the error removing process. Then, we generate the rules by using the extracted attributes as inputs to the Apriori algorithm. The generated association rule model is loaded in the KCS screening system. When the import declaration which should be checked is received, the screening system refers to the model and returns the confidence value based on the supply chain information on the import declaration data. The result will be used to determine whether to check the import case. The 5-fold cross-validation of 16.6% precision and 33.8% recall showed that import declaration data for 2 years and 6 months were divided into learning data and test data. This is a result that is about 3.4 times higher in precision and 1.5 times higher in recall than frequency-based methods. This confirms that the proposed method is an effective way to reduce tariff risks.

• Journal of the Korean Orthopaedic Association
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• v.54 no.4
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• pp.353-360
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• 2019

Purpose: In the treatment of Dupuytren's contracture, the aim of optical treatment is to lower the recurrence rate and reduce complications. This paper reports the results of subtotal fasciectomy in Dupuytren's contracture, extending the excision of palmar fascial structures from the diseased to normal appearing adjacent fascial structure. Materials and Methods: From 2007 to 2017, 45 patients with Dupuytren's contracture treated by subtotal fasciectomy were reviewed retrospectively. The mean follow-up period was 45.9 months. Ninety-two digits were involved (index: 2, middle: 10, ring: 44, little: 36). The predisposing factors and affected joint were reviewed and the preoperative and postoperative contracture was measured. For clinical results, quick disabilities of the arm, shoulder, and hand (quick DASH) were used. Complications, including wound or skin problems, nerve injuries, hematoma, and complex regional pain syndrome, were assessed. Results: Preoperative flexion contracture was 43.2° in the proximal interphalangeal joint and 32.9° in the metacarpophalangeal joint. In nine cases, patients had residual contracture of 9.7° (range, 5°-20°) on average and if the total number of cases were included, the mean residual contracture was 2.3° on average. The quick DASH score at the 12 months follow-up was 12.4. The overall complication rate was 26.6%. Conclusion: Subtotal fasciectomy can be a good surgical treatment option for Dupuytren's contracture with a low recurrence and low complication rate compared to other open procedures.

• 한국노년학
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• v.39 no.4
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• pp.825-846
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• 2019

This study aims to identify subgroups of ageism among young adults of age 20-39, and to examine its relationship to perceptions of generational conflict and elderly welfare policy. Latent Profile Analysis(LPA) was applied on the data 'Survey on Age Integration and Generational Integration', which was executed by institute for Age Integration Researchof Ewha Womans university, and descriptive statistics and cross-tabulation analysis were performed to examine the socio-demographic characteristics of each subgroup. Then, regression analysis was performed to observe the effect of the subgroups on the perceptions of generational conflict and elderly welfare policy. The results are as follows. The resulting subgroups of ageism among young adults were 'compound perception on aging and active age discrimination', 'medium-level aging anxiety and passive age discrimination', and 'low-level aging anxiety and beyond age discrimination'. Subgroups of ageism affected both perceptions of generational conflict and elderly welfare policy, whereas social support only affected perception of elderly welfare policy. Based on the results, political implications, such as activation of education on perception on aging, expansion of generational exchange for age integration, and renewal of social atmosphere for intergenerational coexistence, which will promote social integration

• Journal of Radiation Protection and Research
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• v.22 no.1
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• pp.35-46
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• 1997

A simple and precise method of $^{14}C$ was developed to analyze $^{14}C$ in the environment samples using a commercially available $^{14}CO_2$ absorbent and a liquid scintillation counter. An air sampler and a combustion system were developed to collect HTO and $^{14}CO_2$ in the air and the biological samples simultaneously. The collection yield of $^{14}CO_2$ by the air sampler was in the range of 73-89% . The yield of the combustion system was 97%. In preparing samples for counting, the optimum ratio of $CO_2$ absorbent to the scintillator for mixing was 1:1. No variation of the specific activity of $^{14}C$ in the counting sample was observed up to 70 days after preparation of the samples. The detection limit for$^{14}C$ was 0.025 Bq/gC, which is the level applicable to the natural level of $^{14}C$. The analytical result of $^{14}C$ obtained by the present method were within ${\pm}6%$ of the relative error from the one by the benzene synthesis. The specific activity of $^{14}C$ in the air collected at Taejon during the period of October 1996 ranged from 0.26 to 0.27 Bq/gC. The specific activity of $^{14}C$ in the air collected at 1km from the Wolsong nuclear power plant a 679 MWe PHWR, was $0.54{\pm}0.03$ Bq/gC. The ranges of specific activities of $^{14}C$ in the pine needles and the vegetations from the areas around the Wolsong nuclear power plant were 0.56-0.67 Bq/gC and 0.23-1.41 Bq/gC, respectively.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.199-208
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• 2019

This study reports water-resistant oil-in-water (O/W) emulsion-based sunscreening formulations prepared using a poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG) triblock polymeric surfactant. As a result of a variety of outdoor recreational activities such as swimming and hiking, consumer needs for development of advanced water-resistant sunscreen formulations are increasing. Water-resistant sunscreens are mostly based on water-in-oil (W/O) emulsions, because they should not be wiped off by water or sweat. However, the W/O emulsion formulations have a disadvantage in that the feeling of use is oily and difficult to remove. On the other hand, the O/W emulsion formulations are excellent in achieving the better skin feel as well as the easier removal. However, it is difficult to provide the O/W emulsion formulations with the water-repelling performance, since re-emulsification likely occurs upon getting touch with water. To solve this problem, this study proposes a O/W emulsion-based sunscreen formulation, a triblock polymeric surfactant having relatively high interfacial tension HLB value (~ 10). This allows the sunscreen formulations to exhibit the improved water repellence function by preventing their re-emulsification. The sunscreen formation system prepared in this study would be useful for diversification of functional sunscreen products, taking advantages of its excellent emulsion stability, UV protection performance, long lasting water-resistant function and selective cleansing effect with only foam cleanser.

• The Korean Journal of Mycology
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• v.1 no.1
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• pp.3-11
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• 1973

Four species of nematodes attacking mushroom beds were found in samples taken from 35 mushroom farms throughout Korea. These were Rhabditis sp., Aphelenchoides sp., Ditylenchus sp. and Aphelenchus sp. ,Rhabditis sp. was found from compost and casing from all mushroom farms and the frequencies of Aphelenchoides sp. was 31.4% in the both compost and casing. Both Ditylenchus sp. and Aphelenchus sp. showed 2.7% of frequencies in the compost, none in casing. Temperature and moisture content of compost affected pathogenicity of Aphelenchoides sp. on mushroom mycelia grown in compost. The higher temperature and moisture content the sooner the damage became apparent, and the more rapid was subsequent destruction of mycelia. There was no mycelial destruction at the lowest temperature of $10^{\circ}C$. Rhabditis sp. completely disintegrated mycelia grown in the compost, in the early stage, the numbers of Rhabditis sp. rose gradually and then increased suddenly to reach a peak but soon declined. At first, the pH of Rhabditis-infested spawned compost declined but then rose gradually as mycelia was disintegrated by nematodes. The trend in pH of infested unspawned compost was similar to those of uninfested, unspawned compost. Cultures inoculated with surface-disinfected dead Rhabditis sp. and with tap water used in the nematode extraction procedures showed no mycelial injury associated microorganisms containing within or outside the nematodes even though added by artificial wounding of the mycelia. Cultures artificially wounded showed no injury away from the wounds without the presence of living Rhabditis sp., such wounded mycelia slowly regenerated. On the other hand, artificial wounding accelerated the breakdown of mycelia in the presence of living Rhabditis sp.