• Journal of Power Electronics
• /
• v.2 no.1
• /
• pp.32-45
• /
• 2002

This paper proposes an unified definition of powers for various circuit conditions such as balanced/unbalanced, sinusoidal/non-sinusoidal, and linear/nonlinear, fur single-phase systems and three-phase systems. Conventional reactive power is more classified into an interactive power and an alternating power. These powers are defined both in the time domain and the frequency domain consistently, and agree well with the conservation law. Several important power quality factors are defined to measure and evaluate the power quality fur the various circuits in the single-phase and three-phase systems. Simulation results show the power quality factors can evaluate and classify the various circuit conditions clearly.

• Journal of Fisheries and Marine Sciences Education
• /
• v.18 no.3
• /
• pp.283-292
• /
• 2006

The purpose of this study was to explore the component factors on images of good elementary teacher. 579 elementary teachers in Busan were sampled to be surveyed. The subjects answered open-ended questionnaire related to characteristics of good teacher. The number of items obtained from the questionnaire is 79. The exploratory factor analysis was applied to the data. As a result of exploratory factor analysis, the components of good teacher are classified into five factors : fairness, enthusiasm, commitment, warmth, self-management. All such factors might be related to the personality in common. It shows that teachers think the personality important as a characteristic of good teacher. On the basis of this result we offer a suggestion to the teacher education.

• Journal of Korean Society of Rural Planning
• /
• v.11 no.3 s.28
• /
• pp.11-17
• /
• 2005

Land prices reflect not only the uses of land, but the potential uses as well(Plantinga, 2002) so land values can be applied to very effective indices for deciding regional status and growing potential. The purpose of this study is to deduce determinant factors of regional land prices. Principal determinants of regional land prices are analyzed with a hedonic technique and spatial econometric models based on 2001 statistic data of Korea except large cities. The results provide the followings. 1. The spatial effect of rural regions are very little with adjacent regions. 2. The common index of land price is population density and other determinant factors are different depending on land uses.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.30 no.3
• /
• pp.88-99
• /
• 2019

Objectives: With increasing concerns for the rapidly growing minority population in South Korea, this literature review addressed a range of mental health risks among multiethnic youths (MY) in South Korea by 1) comparing mental health outcomes with those of native-born youths and 2) identifying multiple layers of relevant environmental factors, from family and school relationships to culture. Methods: We reviewed 54 studies that fulfilled specific inclusion criteria. Results: Multiple common risk/protective factors, including family separation, family relationship quality, parental socioeconomic and mental health status, social relationships at school, and cultural acceptance, were noted. Conclusion: In general, empirical evidence indicates that minority youths have relatively heightened risks for emotional and behavioral problems. Future studies must elucidate the complex interplay between multiple risk and protective factors and the long-term adaptation and mental health service utilization of MY.

• Childhood Kidney Diseases
• /
• v.23 no.1
• /
• pp.7-21
• /
• 2019

Nephrotic syndrome (NS) is a common chronic glomerular disease in children characterized by significant proteinuria with resulting hypoalbuminemia, edema, and hyperlipidemia. Renal biopsy findings of diffuse foot processes effacement on electron microscopy and minimal change disease, focal segmental glomerulosclerosis (FSGS), or diffuse mesangial proliferation on light microscopy. It has been speculated that circulating permeability factors would be implicated in the pathogenesis of NS because they have been reportedly detected in the sera of patients and in experimental models of induced proteinuria. Moreover, a substantial portion of the patients with primary FSGS recurrence shortly after transplantation. This report reviews the current knowledge regarding the role of circulating permeability factors in the pathogenesis of proteinuria in NS and suggests future targeted therapeutic approaches for NS.

• Child Health Nursing Research
• /
• v.25 no.1
• /
• pp.48-55
• /
• 2019

Purpose: This study aimed to investigate the status of caffeine-containing energy drink consumption among Korean nursing students and to identify associated psychological factors. Methods: In total, 187 Korean nursing students participated in this cross-sectional study. A self-administered questionnaire was used to identify participants' general characteristics and psychosocial factors (self-esteem, academic stress, depression, and college adjustment) associated with energy drink consumption. Data were analyzed with SPSS using descriptive statistics, the $x^2$ test, the t-test, and logistic regression. Results: More than two-thirds (73.3%) of the participants had consumed energy drinks. Among the investigated psychological factors, depression appeared to most strongly influence energy drink consumption behaviors in this population. Conclusion: The consumption of caffeine-containing energy drinks was found to be common among nursing students preparing to become health care professionals; depressed nursing students were more likely to have consumed energy drinks than non-depressed students. Nursing educators should emphasize the early detection of unhealthy beverage consumption habits and provide appropriate education to enhance healthy behaviors in future health care professionals.

• Research in Mathematical Education
• /
• v.22 no.3
• /
• pp.175-201
• /
• 2019

Spending as much time outside of school as in school, gifted youth are affected by non-school aspects including parents, other family members, peers, mentors, mathematics competitions and camp participations. These influences have been known to shape children's intellectual development, academic achievement, interests, and eventually college and career choices. From interviews with five former Olympians from Korea to identify out-of-school influences on their academic achievement and development, we discovered, in addition to confirmation of previously identified factors, additional sources of positive influence seldom previously mentioned and more common to Korean culture were gleaned - mathematics workbooks and Ha-Gwon. The findings of this study are informative for teachers and parents who are interested in development of gifted youth in providing ways to accommodate their special needs and in showing how they can carefully individualize those sources to be positively affecting intellectual development as well as academic achievement.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.19
• /
• pp.8483-8488
• /
• 2014

Background: Breast cancer is the most common cancer and the second most common cause of cancer-induced mortalities in Iranian women, following gastric carcinoma. The survival of these patients depends on several factors, which are very important to identify in order to understand the natural history of the disease. Materials and Methods: In this retrospective study, 313 consecutive women with pathologically-proven diagnosis of breast cancer who had been treated during a seven-year period (January 2006 until March 2014) at Towhid hospital, Sanandaj city, Kurdistan province of Iran, were recruited. The Kaplan-Meier method was used for data analysis, and finally those factors that showed significant association on univariate analysis were entered in a Cox regression model. Results: the mean age of patients was $46.10{\pm}10.81$ years. Based on Kaplan-Meier method median of survival time was 81 months and 5 year survival rate was $75%{\pm}0.43$. Tumor metastasis (HR=9.06, p=0.0001), relapse (HR=3.20, p=0.001), clinical stage of cancer (HR=2.30, p=0.03) and place of metastasis (p=0.0001) had significant associations with the survival rate variation. Patients with tumor metastasis had the lowest five-year survival rate (37%)and among them patients who had brain metastasis were in the worst condition (5 year survival rate= $11%{\pm}0.10$). Conclusions: Our findings support the observation that those women with higher stages of breast malignancies (especially with metastatic cancer) have less chance of surviving the disease. Furthermore, screening programs and early detection of breast cancer may help to increase the survival of those women who are at risk of breast cancer.

• Journal of Gastric Cancer
• /
• v.11 no.2
• /
• pp.116-121
• /
• 2011

Purpose: Gastric cancer surgery is a common operation in East Asia, such as Korea and Japan, and there has been a significant increase in the need for this procedure due to the aging population. As a result, surgery for the treatment of gastric cancer for elderly patients is expected to increase. This study examined the effect of old age on gastric cancer surgery, and analyzed the operative risk factors for elderly patients. Materials and Methods: From November 2008 to August 2010, 590 patients, who underwent a curative resection for gastric cancers, were enrolled. Patients who underwent palliative or emergency surgery were excluded. A retrospective analysis of the correlation between surgical outcomes and age was performed. The elderly were defined as patients who were over the age of 65 years. Results: The mean age of all patients was 58.3 years, and complications occurred in 87 cases (14.7%). The most common complication was wound infection and severe complications requiring surgical, endoscopic, or radiologic intervention developed in 52 cases (8.8%). The rate of complications increased with increasing age of the patients. Univariate analysis revealed age, comorbidity, extent of resection, operation time, and combined resection to be associated with surgical complications. In particular, age over 75 years old, operation time, and comorbidity were predictive factors in multivariate analysis. In the elderly, only comorbidity was associated with surgical complications Conclusions: The patients' age is the most important factor for predicting surgical complications. Surgeons should pay an attention to the performance of gastric cancer surgery on elderly patients. In particular, it must be performed carefully for elderly patients with a comorbidity.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.18 no.1
• /
• pp.34-41
• /
• 2020

Purpose: This study evaluated aggressive hyperbaric oxygen therapy (HBOT) by understanding various exposure routes of acute carbon monoxide (CO) poisoning, the risk factors causing acute cardiovascular, and neurological toxicity caused by poisoning. Methods: A retrospective study was conducted based on the medical records of 417 acute CO poisoning patients who visited the emergency care unit from March 2017 to August 2019. The exposure routes, HBOT performance, age, sex, medical history (hypertension, diabetes mellitus, ischemic heart disease, heart failure), intentionality, loss of consciousness (LOC), intake with alcohol or sedatives, and initial test results (carboxyhemoglobin (COHb), troponin-I, electrocardiography, echocardiography, brain MRI) were examined. Comparative analysis of the clinical information was conducted between the groups that showed acute cardiovascular toxicity and neurological toxicity, and groups that did not. Results: Among 417 patients diagnosed with acute CO poisoning, 201 cases (48.2%) were intentional, and charcoal briquette was the most common route (169 patients (40.5%)). Two hundred sixteen cases (51.8%) were accidental, and fire was the most common route (135 patients (32.4%)). The exposure route was more diverse with accidental poisoning. Three hundred ninety-nine patients were studied for acute cardiovascular toxicity, and 62 patients (15.5%) were confirmed to be positive. The result was statistically significant in intentionality, LOC, combined sedatives, initial COHb, HTN, and IHD. One hundred two patients were studied for acute neurological toxicity, which was observed in 26 patients (25.5%). The result was statistically significant in age and LOC. Conclusion: Active HBOT should be performed to minimize damage to the major organs by identifying the various exposure routes of CO poisoning, risk factors for acute cardiovascular toxicity (intentionality, LOC, combined sedatives, initial COHb, HTN, IHD), and the risk factors for acute neurological toxicity (age, LOC).