• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.11
• /
• pp.5879-5884
• /
• 2013

With the rapid industrialization and economical development, the electricity demands of the industrial facilities and densely populated large cities are continuing to increase in Korea. The increase in the power consumption requires the extension of power facilities, but it is difficult to secure spaces for equipment installation in the limited space of urban areas. In addition, the 154 kV or 345 kV transmission systems in Korea has a short transmission distance, and are connected to one another in network structures that ensure the high reliability and stability of power supply. This structure reduces the impedance during the fault in power system, and increases the magnitude of in the short circuit fault current. The superconducting fault current limiter (SFCL) was devised to effectively address these existing problems. The SFCL is a new-concept eco-friendly protective device that ensures fast operation and recovery time for the fault current and does not need additional fault detection devices. Therefore, many studies are being conducted around the world. In this paper, based on the wiring method the initial fault current characteristics, current limiting characteristics, according to the incident angle and the change in inductance current limiting characteristics were analyzed in a multifaceted methods.

• Korean Journal of Community Nutrition
• /
• v.11 no.3
• /
• pp.307-316
• /
• 2006

This study was conducted to investigate the relationships among body composition, dietary intake, and clinical blood indices in college students by body mass index (BMI). Their body compositions were determined by means of BIA (Bioelectrical Impedance Analysis) method. Their dietary intake was determined using a 3-day record method and their hematological indices were determined by semi-automated microcell counter (Sysmex F-520). Their serum lipid levels were measured using biochemical analyzer (Spotchem). Subjects were classified as underweight, normal or over-weight groups according to their BMI. The subjects were 69 healthy college students aged 20 to 26 years. The average age, height, weight, and BMI was 21.3 years, 162.6 cm, 54.4 kg, and $20.6cm/m^2$, respectively. Their average consumption of energy was 1693 kcal, 84.7% of RDA and their mean ratio of carbohydrate: protein: fat were 54.5 : 16.4 : 29.0. There was no significant difference in nutrient intake among the groups except ${\beta}$-carotene and vitamin C. The ${\beta}$-carotene intake was significantly higher in the underweight group. Vitamin C intake was significantly higher in the overweight group. The mean intakes of Ca, Fe, Zn and folate of subjects were 74.8% to 83.2% of RDA. Especially, intakes of Ca, Fe, Zn and folate were lower in the abnormal weight groups. The overall mean values of the hematological indices in female college students were within the normal range and there was no significant difference among the groups. However, anemic subjects with hemoglobin (< 12 g/dl) and hematocrit (< 36 g/dl) accounted for about 11% of the subjects. The everall mean values of the serum lipid levels were within the normal range and there was no significant difference among the groups. But serum HDL-cholesterol level of the overweight group was lower than that of the other groups. LDL-/HDL-cholesterol ratio and AI index were significantly higher in the overweight group compared to the other groups. Based upon this study, it is necessary for college women to be educated regarding consuming more Ca, Fe, Zn, folate and less fat and cholesterol in order to have better health promotion.

• Journal of Nutrition and Health
• /
• v.41 no.8
• /
• pp.767-775
• /
• 2008

Uncoupling protein-1 (UCP-1) plays a major role in thermogenesis at brown adipose tissues and has been implicated in the pathogenesis of obesity and metabolic disorders. The purpose of this study was to estimate the effects of A-3826G polymorphism in 117 Korean prepubertal children aged 8-11 years olds. Anthropometry by bioelectrical impedance analysis method, plasma lipid profiles by auto-biochemical analyzer and UCP-1 genotyping by PCR-RFLP were done. The frequencies of UCP-1 genotypes were AA; 17.7%, AG; 57.8%, GG; 26.6%. The frequencies of each G allele (55.5%) was similar to Japanese's (49%) and higher than Caucacian's (25%). No correlation UCP-1 polymorphism and BMI (kg/$m^2$) or the degree of obesity described by the relative percentiles of the standard weight according to height in prepubertal children. However, plasma total- and LDL-cholesterol were significantly increased in G allele when sex, age and weight were adjusted. Our results suggested that G allele of UCP-1 gene was stronger risk factors in hyperLDLcholesterolemia than A allele. This impact might be progressed as the precaution against the revalence of obesity based-metabolic disease.

• Journal of Radiation Protection and Research
• /
• v.30 no.1
• /
• pp.17-25
• /
• 2005

Since the safety of nuclear power plant has been becoming a big social issue the exposure dose of radiation for workers has been one of the important factors concerning the safety problem. The existing calculation methods of radiation dose used in the planning of radiation work assume that dose rate does not depend on the location within a work space thus the variation of exposure dose by different work path is not considered. In this study, a modified numerical method was presented to estimate the exposure dose during radiation work in radwaste storage considering the effects of the distance between a worker and sources. And a new numerical algorithm was suggested to search the optimal work path minimizing the exposure dose in pre-defined work space with given radiation sources. Finally, a virtual work simulation program was developed to visualize the exposure dose of radiation doting radiation works in radwaste storage and provide the capability of simulation for work planning. As a numerical example, a test radiation work was simulated under given space and two radiation sources, and the suggested optimal work path was compared with three predefined work paths. The optimal work path obtained in the study could reduce the exposure dose for the given test work. Based on the results, tile developed numerical method and simulation program could be useful tools in the planning of radiation work.

• Journal of Food Hygiene and Safety
• /
• v.32 no.2
• /
• pp.83-88
• /
• 2017

We introduced disposable amperometric immunosensors for the detection of Sildenafil and Vardenafil (SDF/VDF) based on screen printed carbon electrodes. The developed immunosensors were used as a non-competitive sandwich-type enzyme immunoassay with a horseradish peroxidase label. The sensors were constructed on screen printed carbon electrodes by the simple electrochemical deposition of a reduced graphene oxide and chitosan (ErGO-CS) composite. To evaluate the sensing chemistry and optimize the sensor characteristics, a series of electrochemical experiments were carried out including electrochemical impedance spectroscopy, cyclic voltammetry and amperometry. The sensors showed a linear response to SDF/VDF concentrations in a range from 100 pg/mL to 300 ng/mL. The lower detection limit was calculated to be 55 pg/mL, the sensitivity was calculated to be $1.02{\mu}Ang/mL/cm^2$, and the sensor performance exhibited good reproducibility with a relative standard deviation (RSD) of 7.1%. The proposed sensing chemistry strategy and the sensor format can be used as a simple, cost-effective, and feasible method for the in-field analysis of SDF/VDF in functional or health supplement food samples.

• The Journal of the Acoustical Society of Korea
• /
• v.41 no.3
• /
• pp.278-286
• /
• 2022

In this study, a 33-mode Free-Flooded Ring (FFR) transducer was designed to apply piezoelectric single crystal PIN-PMN-PT, which has high piezoelectric constants and electromechanical coupling coefficient. To ensure low-frequency high transmitting sensitivity characteristics with a small size of FFR transducer, the commercial FFR transducer based on piezoelectric ceramics was compared. To develop the FFR transducer with broadband characteristics, a piezoelectric segmented ring structure inserted with inactive elements was applied. The oil-filled structure was applied to minimize the change of acoustic characteristics of the ring transducer. It was verified that the transmitting voltage response, underwater impedance, and beam pattern matched the finite element numerical simulation results well through an acoustic test. The difference in the transmitting voltage response between the measured and the simulated results is about 1.3 dB in cavity mode and about 0.3 dB in radial mode. The fabricated FFR transducer had a higher transmitting voltage response compared to the commercial transducer, but the diameter was reduced by about 17 %. From this study, it was confirmed that the feasibility of a single crystal-applied FFR transducer with compact size and high-power characteristics. The effectiveness of the performance prediction by simulation was also confirmed.

• Exercise Science
• /
• v.21 no.1
• /
• pp.111-120
• /
• 2012

The purpose of the study was to assess the effects of different cardiorespiratory fitness response to exercise training on cardiovascular disease and adipocytokine release and gene expression in abdominal obesity women. forty eight middle-age women were divided to a exercise-responder (n=34) group (ERG) and a exercise-nonresponder (n=14) group (ENRG) based on cardiorespiratory fitness after exercise training (12weeks, 1200 kcal/week, moderate-vigorous intensity, walking and jogging). Cardiorespiratory fitness was measured using maximal oxygen uptake with metabolic gas analysis and body composition was determined by bioelectrical impedance. We measured lipid and glucose profiles, blood adipocytokines and adipocytokine genes expression in adipose tissue. Waist girth (p=0.040), and %body fat (p=0.031) were significantly decreased in ERG than ENRG. Triglyceride (p=0.023) and systolic blood pressure (0.046) were significantly decreased in ERG than ENRG. Blood leptin (p=0.022) was significantly decrease in ERG than ENRG but leptin gene expression was decreased both groups (p<0.001). These results show that exercise-responder group improved cardiovascular disease risk factors and adipocytokine more than exercise-nonresponder group after exercise training. Moreover, exercise-nonresponders group show that obese indices and blood leptin and leptin gene expression in adipose tissue were decreased despite the failure to improve fitness. Therefore, regular exercise training seems to give health benefits although the failure to improve fitness.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.34 no.1
• /
• pp.77-84
• /
• 2024

Objectives: Interventions promoting physical exercise and healthy habits in workplaces have been shown to be effective in reducing risk factors for metabolic syndrome. This study was conducted to examine the effects of an individualized conditioning exercise program of IT company office workers with or at higher risk of metabolic syndrome. Methods: A total of 444 IT company office workers with or at higher risk of metabolic syndrome participated in a 3-month conditioning exercise program. Body composition data using bioelectrical impedance analysis and cardiopulmonary data using cardiopulmonary exercise testing from 53 individuals (mean age: 34.8 ± 7.1 years, sex : 21% female, height : 170.4 ± 6.8 cm, weight : 75.2±12.2 kg, body mass index : 25.8±3.3 kg/m²) who have successfully completed pre-test, intervention, and post-test were analyzed. The 12 weeks intervention encompassed: (1) health counseling (2) supervised exercise(endurance-based, aerobic exercise, or circuit training once a week for 50 minutes at heart rate reserve(HRR) of 77-95%) (3) self-directed exercise and biweekly health screening checks. Results: The results indicated a significant decrease in body weight, body fat mass and body mass index, respectively. Moreover, VO₂peak, AT VO₂ and AT Time significantly improved, respectively. Resting blood pressure(SBP/DBP) showed positive changes but were not statistically significant. We observed the correlation between characteristics of participants and rate of changes in cardiopulmonary outcomes of participants, there are no significant correlation. These results indicate positive changes in body composition and cardiorespiratory fitness parameters following individualized conditioning exercise program. Conclusions: Individualized workplace exercise program for preventing metabolic syndrome can lead to improvements in body composition and cardiorespiratory fitness.

• Clinical and Experimental Pediatrics
• /
• v.53 no.3
• /
• pp.335-340
• /
• 2010

Purpose : This study was designed to determine the effects of a school-based obesity-management program on obese primary school children. Methods : A total of 995 children (6-2 years old) in a primary school were screened in March 2008, and of those, 101 obese students (44 boys and 57 girls, body mass index (BMI) ${\geq}95$ percentile) were enrolled for a study group. The schoo-lbased, obesity management program, which includes physical exercise and nutritional education, was conducted as part of an extracurricular program for 12 weeks. The measurement of height, weight, waist circumference, blood pressure (BP), and bioelectrical impedance analysis (BIA) was performed before and after the program.Results : Height and weight increased significantly (P <0.05). The BMI and obesity index decreased significantly (P <0.01). Systolic and diastolic BP decreased significantly (P <0.01). BMI decreased in 61.4% of boys and 66.7% of girls. Protein and basal metabolic rate (BMR) increased significantly on the BIA (P <0.01). Fat decreased significantly (P <0.05). The total body water (TBW) and percent body fat (PBF) decreased significantly (P <0.01). The changes in protein, fat, TBW, PBF, and BMR significantly correlated to the change in BMI (P <0.05). In a multiple logistic regression analysis, BMI change was significantly correlated to the changes in protein and fat content (P <0.01). Conclusion : The school-based obesity management program is a very effective way to manage obesity for obese primary school children.

• Journal of Applied Biological Chemistry
• /
• v.52 no.1
• /
• pp.8-14
• /
• 2009

This study was conducted to assess the effects of diet food containing Jerusalem artichoke's inulin, lotus leaf, and herb on weight and body fat. Participants in this study were selected based on the following criteria: BMI over $25kg/m^2$, body fat percentage higher than 25%, abdominal obesity level of 0.85 measured by body composition measurement unit (ZEUS 9.9 PLUS, Korea) total 24 female and male university students over 20 of age were assigned to two different groups: control group and diet group and the study was carried out for 30 days. When we measured what the tester's body weight and height, we used an automatic measure machin which is called IMI-1000 from Immanuel company and when we measured what the hip and wist circumference, we used a tape measure. When we measured body mss index (BMI), body Int, body mass, lean mass, waist/hip ratio (WHB), obesity index, we used a ZEUS9.9 PLUS-Korea which is based on bioelectrical impedance analysis, The food intake was checked by means of diet record method to be input into CAN program in order to analyze nutrient intake. Our findings indicated that the diet group, as compared to the control group, lost weight of approximately 2.5 kg and showed statistically significant difference. In addition the level of body Int, muscle, abdominal obesity, obesity, waist and bottom measurement all showed significant decrease after study period. However, there was no big difference in body fat percentage because both body fat level and muscle level dropped together, Putting all these together, diet food in this study containing Jerusalem artichoke's inulin, lotus leaf powder, and herbs powder including nettle, eucalyptus was found to be effective in significant reduction of weight and body fat and obesity-related body indicators. Also, it is considered that this diet food has potential to prevent and improve effectively obesity from abnormal fat accumulation.