• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.8
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• pp.115-122
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• 2017

In this paper, we propose a novel power factor compensation system using slidac. The proposed power factor compensation system compensates the power factor by adjusting the output voltage of the slidac. In the conventional power factor compensation system using capacitor bank method, the power factor compensation error occurs depending on the load condition due to the limitation of the compensation capacitor capacity. However, the proposed system can finely change slidac output voltage applied to the capacitor, therefore power factor can be compensated up to 100% without error. We compare the proposed system with the conventional system, and confirm that the proposed system has excellent power factor compensation performance through simulations and experiments. If the proposed power factor compensation system is applied to an industrial field, a power factor compensation performance can be maximized. As a result, it is possible to reduce of electricity prices, reduce of line loss, increase of load capacity, ensure the transmission margin capacity, and reduce the amount of power generation.

• Archives of Plastic Surgery
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• v.33 no.1
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• pp.95-100
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• 2006

The challenge of accurately predicting eyelid height after blepharoptosis surgery is well-known problem even in complete hands. From May, 1988 to December, 2004, authors reviewed 182 cases(240 eyes) of blepharoptosis corrected by frontalis muscle transfer or levator resection and had experienced 10 cases(15 eyelids) of early reoperation around 1 week. The period from initial operation to reoperation are between six to eight days and mean period is seven days. Initial operative procedures were frontalis muscle transfer in 3 cases(4 eyelids) and levator resection in 7 cases(11 eyelids). Follow up period ranged from 6 months to 16 years. Early adjusting surgery was performed in accordance with the preoperative and postoperative degree of ptosis of patient and considering previous operative technique. The results are evaluated according to the criteria of an ideal correction by Souther and Jordan. Seven patients have good or satisfactory results(less than 1 mm asymmetry, good in 5 cases and satisfactory in 2 cases). Three patients(5 eyelids) recorded as poor results(more than 2 mm asymmetry). Even if early or late reoperation can be effective in correcting unsatisfactory results after correction of blepharoptosis, early reoperation is better than later reoperation because early reoperation can offer a reduction in time to final result, the ease with which it is performed, potential cost savings. The experience of surgeon is also important factor for the reatment of recurred blepharoptosis

• Journal of Korean Library and Information Science Society
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• v.43 no.4
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• pp.183-199
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• 2012

This study is to develop an operating model of Conspectus for online resources by using mechanistic quality factor. Based on some empirical statistics about resource use behaviour such as collection rate, use rate, search rate, the mechanistic quality factor was calculated and applied to each subject by adjusting its acquisition level of Conspectus. according to the result of this study, Acqusition levels of the subject such as technical science which shows higher in use rate, and those such as history and social science which show higher in search rate, should be adjusted to a higher acquisition level, and those of others to the same or a lower level.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.2
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• pp.87-96
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• 2004

This paper summarizes the research results of the load management for pole transformers done in 1997-1998 and 2000-2002. The purpose of the research is to enhance the accuracy of peak load estimation in pole transformers. We concentrated our effort on the acquisition of massive actual load data for modifying the load regression coefficients, which related to the peak load estimation of lamp-use customers, and adjusting the demand-factor coefficients, which used for the peak load prediction of motor-use customers. To enhance the load regression equations, the 264 load data acquisition devices are equipped to the sample pole transformers. For the modification of demand factor coefficients, the peak load currents are measured in each customer and pole transformer for 13 KEPCO (Korea Electric Power Corporation) distribution branch offices. Case studies for 50 sample pole transformers show that the proposed coefficients could reduce estimating error of the peak load for pole transformers, compared with the conventional one.

• The Korean Journal of Health Service Management
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• v.13 no.4
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• pp.243-252
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• 2019

Objectives: This study aimed to determine whether the self-rated health (SRH) could be a risk factor for compulsion. Methods: Data related with compulsion and SRH information were collected from 532 young adults aged over 20 years in South Korea. The distribution of the high and low SRH groups was analyzed using the chi-square test, whereas difference in quality of life (QoL) was analyzed using the t-test. Logistic regression was used to analyze the odds ratio (OR). Results: In the high and low-SRH groups, 44 (28.8%) and 23 (31.5%) men and 24 (10.4%) and 21 (27.6%) women, respectively, were at risk for compulsion (p<.001). For women, the compulsion scores of the low and high-SRH groups, respectively, were 15.8±9.53 and 9.9±8.47 (t=5.071, p<.001). The low-SRH group had higher ORs compared with the high-SRH group among women (OR 3.277, 95% confidence interval 1.699 - 6.321, p<.001) in the original model, and this phenomenon was significant even after adjusting for age and residence type. Conclusions: Low SRH may be a risk factor for compulsion. Further research for improving SRH by developing preventive measures against compulsion is necessary.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.2
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• pp.55-61
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• 2011

We propose power-saving real-time scheduling method for mixed task sets which consist of both time-based periodic and event-based aperiodic tasks in the automotive operating system. In this system, we have to pursue maximization of power-saving using the slack time estimation and minimization of response time of aperiodic tasks simultaneously. However, since these two goals conflict each other, one has to make a compromise between them according to the given application domain. In this paper, we find the adjustment factor which gives better response time of aperiodic tasks with slight power consumption increase. The adjustment factor denotes the gravity of response time for aperiodic tasks. We apply the ccEDF scheduling for time-based periodic tasks and then calculate new utilization to be applied to the adjustment factor. In this paper, we suggest the lccEDF algorithm to make a tradeoff between the two goals by systematically adjusting the factor. Simulation results show that our approach is excellent for variety of task sets.

• Nutrition Research and Practice
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• v.7 no.5
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• pp.380-384
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• 2013

Zinc may participate in blood pressure regulation and in the pathogenesis of hypertension. The study examined the relationship between zinc status and blood pressure in obese Korean women. Forty obese women (body mass index (BMI) ${\geq}25kg/m^2$) aged 19-28 years participated in this study. Zinc intake was estimated from one 24 hour recall and 2-day diet records. Serum and urinary zinc concentrations were determined by atomic absorbance spectrophotometry. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using an automatic sphygmometer. Metabolic variables, such as waist circumference, triglyceride, high density lipoprotein (HDL) cholesterol, fasting glucose, and fasting insulin, were also measured. Dietary zinc intake of obese women was averagely 7.5 mg/day. Serum zinc and urinary zinc concentrations were $13.4{\mu}mol/L$ and $378.7{\mu}g/day$, respectively. Averages of SBP and DBP were 119 mmHg and 78 mmHg. Dietary zinc intake was negatively correlated with SBP after adjusting for energy intake (P < 0.05), but serum and urinary zinc concentrations were not found to be correlated with SBP or DBP. Multivariate linear regression analysis showed that dietary zinc intake was inversely associated with SBP in obese women after adjusting for body weight, energy intake and sodium intake (P = 0.0145). The results show that dietary zinc intake may be an independent risk factor of elevated SBP in obese Korean women.

• Journal of Korean Public Health Nursing
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• v.31 no.2
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• pp.234-243
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• 2017

Purpose: This study was conducted to evaluate the socioeconomic status as a risk factor for hepatitis C virus infection among community-dwelling adults in Korea. Methods: This study was a cross-sectional study including 2,617 adults. Data from hepatocellular carcinoma epidemiological investigation and information regarding three markers of socioeconomic status, education, employment, household income, were obtained. Multiple logistic regression was performed to calculate odds ratios (ORs) for hepatitis C virus infection for socioeconomic status markers, adjusting for the other soioeconomic status marker, behavioral and hepatitis-related factors. Results: Of the 2,617 study subjects, 104 subjects infected with hepatitis C virus and prevalence was 4%. When compared to subjects with a lowest education, ORs was 0.16 (95% confidence interval [CI]: 0.04-0.69) for highest education group. After adjusting behavioral and hepatitis-related factors, ORs was 0.20 (0.05-0.87) for highest education compared with lowest group. Conclusion: Low educational level was associated with an increased risk of hepatitis C virus infection.

• The Korean Journal of Applied Statistics
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• v.15 no.1
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• pp.1-8
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• 2002

Categorizing prognostic factors is very useful for a disease diagnosis, determination of treatment and study eligibility criteria. Methods often used to categorize factors are to select a cutpoint by biological theory, by graphical examination, by the minimum p-value approach. The last method involves multiple testing, and several methods for adjusting p-values have been developed. This study determines the cutpoint of tumor size to separate patients of high risk of relapse after hepatic resection of hepatocellular carcinoma.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.2
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• pp.13-24
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• 2019

Objective: Recently, Korean adolescent has the problems of nutrition unbalance due to bad eating habits. Also, single-parent and step-parent families have consistently increased because of the increase of divorce rates. Adolescent who lives with a single or step family tends to have unhealthy behaviors and habits. The purpose of this study was to analyze relationship between family structure and irregular breakfast among Korean adolescent. Method: We analyzed 60,040 participants from Korean Youth Risk Behavior Web-based Survey 2018. Study variables included family structure and irregular breakfast. Control variables were sex, school, economic status, parent education levels, drinking, smoking and nutrition education. In terms of this study, descriptive, Chi-square and multivariate logistic regression analysis were performed. Results: After adjusting for socio-demographic variables among boys, family structure was associated with irregular breakfast (living with both parents reference group vs living with single-parent : OR 1.250, 95% CI: 1.142, 1.368). Among girls, after adjusting for control variables, family structure was also associated with irregular breakfast (living with both parents reference group vs living with no both parents : OR 1.409, 95% CI: 1.065, 1.865). Conclusion: According to this study, family structure would be a risk factor of adolescent breakfast habit. Nutrition programs for adolescent should consider these factors.