• Proceedings of the KIEE Conference
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• summer
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• pp.267-269
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• 2004

Recently, due to increasing the application of power electronic equipment, harmonics generated from the non-liner load are fairy produced. Harmonics can cause a distribution problems such as the overheating of distribution transformer, the breakdown of device and communication interference. Interest about power quality decline of distribution system is very increased. In this paper, we are measured the harmonic voltage and current of distribution system to analyze harmonic characteristics, and it is analyzed Total Harmonic Distortion(HTD). Also, we are modeled distribution system using PSCAD/EMTDC. And it is analyzed harmonic voltage and current in steady-state. The study result have been indicated the utility about harmonics analysis and modeling for distribution system.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.80-87
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• 2022

Lack of sufficient battery capacity is one of the most important challenges impeding the development of wireless sensor networks (WSNs). Recent innovations in the areas of wireless energy transfer and rechargeable batteries have made it possible to advance WSNs. Therefore, in this article, we propose an energy-efficient charging of sensors in a WSN scenario. First, we have formulated the problem as an integer linear programming (ILP) problem. Then a utility function-based greedy algorithm named UGreedy/UF1 is proposed for solving the problem. Finally, the performance of UGreedy/UF1 is analyzed along with other baseline algorithms: UGreedy/UF2, 2-opt TSP, and Greedy TSP. The simulation results show that UGreedy/UF1 performs better than others both in terms of the deadline missing ratio of sensors and the total energy consumption of UAVs.

• Journal of the Korean Society for information Management
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• v.23 no.1 s.59
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• pp.121-138
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• 2006

This study attempts to derive an economic analysis model for journal evaluation and conducts a case analysis based on the model. Total costs are calculated and include administrative fees (such as binding, ordering, claiming, etc.) and subscription costs. The model quantifies qualitative benefits to users, a utility that combines usage data that has also been evaluated in the existing economic analysis models. The model is designed by the usage statistics of the web-based electronic journals, which have become important resources for research. Rankings are assigned based on how items are utilized to the goal of the mother institution. In the case study based on the KDI School Library, the highest ranking off was assigned to journals that patrons used for citation in their outputs. For journals that were used background information, i.e., full text downloading or browsing , each was assigned ranking of 2 and 1, respectively. According to the analysis, the top 20 journals provided 75% of the entire library utility, showing different user behaviors among different cohorts. We expect that the model makes it possible for librarians to measure the value of journals. It can provide a basic tool for journal selection, particularly in special libraries with custom needs.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.258-269
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• 2021

The purpose of this study was to explore relations between college students' dating violence perception and professional help-seeking attitudes and other factors that affect professional help-seeking attitude and their effect size. 508 students from a college in Chungcheong region responed to self-report questionnaires. Data were analyzed by Partial correlation coefficients and regression analysis using the SPSS 22.0 program. As a resullt, self-disclosure and anticipated utility on self-disclosure had positively effect on professional help-seeking attitudes. In contrast, violence perception, perceived social support, risk on self-disclosure and barriers to seeking help had negative effect on professional help-seeking attitudes. The total effect size was 46.1%, and the effect size of anticipated utility on self-disclosure was the largest, followed by risk on self-disclosure and barriers to seeking help. This study contributed to the broading of dating violence research topics and provided the directions to the endavour to increase the use of professional services among college students

• Membrane and Water Treatment
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• v.14 no.2
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• pp.65-76
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• 2023

Given the limited water resources and the presence of multiple decision makers with different and usually conflicting objectives in the exploitation of water resources systems, especially dam's reservoirs; therefore, the decision to determine the optimal allocation of reservoir water among decision-makers and stakeholders is a difficult task. In this study, by combining a fuzzy VIKOR technique or fuzzy multi-criteria decision making (FMCDM) and the Young's bilateral bargaining model, a new method was developed to determine the optimal quantitative and qualitative water allocation of dam's reservoir water with the aim of increasing the utility of decision makers and stakeholders and reducing the conflicts among them. In this study, by identifying the stakeholders involved in the exploitation of the dam reservoir and determining their utility, the optimal points on trade-off curve with quantitative and qualitative objectives presented by Mojarabi et al. (2019) were ranked based on the quantitative and qualitative criteria, and economic, social and environmental factors using the fuzzy VIKOR technique. In the proposed method, the weights of the criteria were determined by each decision maker using the entropy method. The results of a fuzzy decision-making method demonstrated that the Young's bilateral bargaining model was developed to determine the point agreed between the decisions makers on the trade-off curve. In the proposed method, (a) the opinions of decision makers and stakeholders were considered according to different criteria in the exploitation of the dam reservoir, (b) because the decision makers considered the different factors in addition to quantitative and qualitative criteria, they were willing to participate in bargaining and reconsider their ideals, (c) due to the use of a fuzzy-logic based decision-making approach and considering different criteria, the utility of all decision makers was close to each other and the scope of bargaining became smaller, leading to an increase in the possibility of reaching an agreement in a shorter time period using game theory and (d) all qualitative judgments without considering explicitness of the decision makers were applied to the model using the fuzzy logic. The results of using the proposed method for the optimal exploitation of Iran's 15-Khordad dam reservoir over a 30-year period (1968-1997) showed the possibility of the agreement on the water allocation of the monthly total dissolved solids (TDS)=1,490 mg/L considering the different factors based on the opinions of decision makers and reducing conflicts among them.

• Journal of Korea Trade
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• v.27 no.2
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• pp.115-129
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• 2023

Purpose - This study empirically analyzes the consumer value of risk management associated with illegal, unreported, and unregulated (IUU) fishing of fishery products imported to Korea. The global regulatory paradigm for IUU fishing has shifted from production-centered to market-centered. As a result, changes in the international fisheries trade environment emphasizing "transparency" and "legality" of the production process are accelerating. Therefore, changes in the management systems of fishery products entering the country are also needed. Accordingly, this study estimated the consumer value for risk management of IUU fishing, targeting major fish species imported to Korea, and derived the feasibility of introducing related policies. Design/methodology - This study used the choice experiment as an analysis model to estimate consumers' willingness to pay for the "possibility to check for IUU fishing." The choice experiment assumes that the value of a good or service is composed of separable attributes and that the sum of the part-worth of these individual attributes becomes the total value. In this study, respondents were presented with profiles comprising three attributes (country of origin, price, and possibility of checking IUU fishing) and the levels of frozen poulp squid, the subject of the analysis. The participants were asked to select their preferred profile. The marginal willingness to pay for each attribute was derived from the results of the respondents' choices using conditional logit model estimates. Findings - There is a marked difference in utility based on the preference of the country of origin of fishery products among consumers. In addition, the utility of fishery products that have undergone IUU fishing verification was observed to be higher, with the utility marked to be higher for lower prices. Originality/value - Estimating the policy value of the risk management in IUU fishing of imported fisheries products in this study is a novel attempt that has never been conducted before. Several studies have been conducted to assess the risk of IUU fishing associated with the import of fishery products internationally. However, such studies are yet to be conducted in Korea. Instead, policies and studies have focused on issues related to complying with trading partners' legal and transparent standards for exporting fishery products. This study should be the beginning of more in-depth empirical and theoretical explorations to establish order in the domestic seafood market and respond to changes in international regulations on IUU fishing.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.34 no.4
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• pp.258-267
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• 2023

Objectives: This study aimed to compare the utility of the Psychoeducational Profile-Revised (PEP-R), Korean Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (K-WPPSI-IV), and Vineland Adaptive Behavior Scale, Second Edition (VABS-II) for evaluating developmental disabilities (DD) in preschool children. Additionally, we examined the correlations between the PEP-R, K-WPPSI-IV, and VABS-II. Methods: A total of 164 children aged 37-84 months were assessed. Children's development was evaluated using the PEP-R, K-WPPSI-IV, VABS-II, Preschool Receptive-Expressive Language Scale, and Korean Childhood Autism Rating Scale, Second Edition. Results: Of the 164 children, 103 had typical development (TD) and 61 had DD. The mean of the PEP-R Developmental Quotient (DQ), K-WPPSI-IV Full-Scale Intelligence Quotient (FSIQ), and VABS-II Adaptive Behavior Composite (ABC) scores were significantly higher in the TD group than in the DD group (p<0.001). The estimated area under the curve of the PEP-R DQ, K-WPPSI-IV FSIQ, and VABS-II ABC scores was 0.953 (95% confidence interval [CI]=0.915-0.992), 0.955 (95% CI=0.914-0.996), and 0.961 (95% CI=0.932-0.991), respectively, which did not indicate a statistically significant difference. The PEP-R DQ scores were positively correlated with the K-WPPSI-IV FSIQ (r=0.90, p<0.001) and VABS-II ABC scores (r=0.84, p<0.001). A strong correlation was observed between the K-WPPSI-IV FSIQ and VABS-II ABC scores (r=0.89, p<0.001). Conclusion: This study found that the PEP-R, K-WPPSI-IV, and VABS-II effectively distinguished DD from TD in preschool children, and no significant differences in utility were observed between them.

• The Journal of Korean Medicine
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• v.34 no.4
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• pp.46-55
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• 2013

Objectives: Classifying the pattern of jaundice during diagnosis will significantly improve the outcome of common KM interventions. This study aimed at determining an objective index for accurately diagnosing heat and dampness KM patterns in patients with jaundice. Methods: We systematically reviewed laboratory findings from case reports published in the scientific literature of Korean medicine. Cases were classified as following either the heat or dampness pattern. Biochemical indices were compared using a Bayesian factor (BF) analysis and standard t-tests. Results: The laboratory findings of 32 patients were evaluated. The heat pattern was observed in 17 patients and the dampness pattern in 15. No significant differences were observed between the 2 groups in terms of white blood cell count (BF=1.659); hemoglobin concentration (BF=2.627); platelet count (BF=1.019); or levels of direct bilirubin (BF=1.453), aspartate aminotransferase (BF=1.226), alanine aminotransferase (BF=1.340), alkaline phosphatase (BF=2.344), or gamma-glutamyl transpeptidase (BF=2.782). However, total bilirubin levels were significantly higher in the dampness pattern group (BF=0.854, P-value=0.070). Conclusions: Patients with high total bilirubin levels may predominantly follow the dampness pattern, while those with low levels may predominantly follow the heat pattern. These results are expected to be useful for the development of timely and efficient KM treatments as well as new integrative therapeutic approaches for jaundice. However, further studies are essential to fully validate the utility of total bilirubin as a biomarker for differentiating between heat and dampness patterns.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.29-38
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• 2008

This study intends to analyze the value of school forests, one type of urban forest. For this purpose, four attributes of school forests were investigated, considering ecological, educational, social and economic values using a conjoint model as the stated preference. Based on literature reviews, the levels of the four attributes were selected, and a questionnaire survey was given to 279 urban residents divided into 2 groups: those impacted by school forests and those not. The study results suggest that the most important attribute of school forests is economic value, and next is ecological, social and educational value according to the part-worth model. The fitness level of the model is 0.900(total group) which is very significant. As for the economic value, free and 1,000 won are more critical factors than the other 2 levels, 5,000 won and 10,000 won and air pollution purification and making the school landscape are more critical factors than small habitats and microclimate factors. In addition, regarding the social value related to residents' leisure activities，the utility of nature observation is higher than walking and exercising. Finally, for educational value, understanding nature's importance is more critical than the emotions and learning of students. The estimated WTP per household/month is 3,580 won, the group related to school forestsis 3,650 won and the non-related group is 3,540 won. Based on these results, the estimated total economic value of all households per year is 6,820 hundred million won. The group related to school forests is 6,970 hundred million won and the non-related group is 6,750 hundred million won.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.1
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• pp.63-67
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• 2000

Purpose: Biliary atresia, one of the major causes of neonatal cholestais, is an idiopathic, serious disorder, affecting the newborn that results in complete obstruction of biliary tract. Successful reestablishment of bile flow is dependent on early surgical intervention, early diagnosis is imperative. The authors evaluate the utility of Tc-99m-labeled diisoprpyliminodiacetic acid (DISIDA) hepatobiliary scintigraphy in the diagnosis of biliary atresia. Methods: From January, 1995 to August, 1999, total 60 patients with neonatal cholestasis underwent Tc-99m DISIDA hepatobiliary scintigraphy at Asan Medical Center. Results: The undelying causes of neonatal cholestasis were biliary atresia in 14, neonatal hepatitis in 33, intrahepatic bile duct paucity in 9, and total parenteral nutrition induced cholestasis in 4. All patient with biliary atresia were interpreted correctely in DISIDA hepatobiliary scintigraphy, showing 100% sensitivity. Of the 46 patients with neonatal hepatitis and other causes, 37 patients had intestinal radioactivity showing 80% specificity. Conclusion: Visualization of DISIDA in the intestinal tract indicates patency of the biliary ducts and excludes the diagnosis of biliary atresia. But the absence of intestinal excretion on the DISIDA hepatobiliary scintigraphy dose not necessarily indicate biliary atresia.