• Journal of Family Resource Management and Policy Review
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• v.11 no.1
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• pp.65-81
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• 2007

The purpose of this study is to analyze income and consumption expenditure patterns over the family life cycle. The data used in this study is the 2004 Survey data from the Annual Report on the Family Income and Expenditure Survey data which are included salary and wage earners' households living in urban areas. The income and expenditure data of 20,383 households are analyzed. The family life cycle is classified into six stages and the items of expenditure are classified into 12 categories. The data are analyzed by descriptive statistics, $X^2$ test, F-test, and Duncan's multiple range test using SAS 8.0 package program. The major findings of this study are as fellows: First, the average monthly family income of the total sample is 3,480,000 won. The proportion of regular and irregular income among the total family income is 95.5% and 4.5% respectively. Second, the amount and ratio of monthly regular income fur each category are significantly different over the family life cycle. Third, the average monthly family expenditure of the total sample is 2,250,000 won. The amount and ratio of monthly expenditure of all items are significantly different over the family life cycle. The highest expenditure item is the traffic expanse and phone charge.

• Journal of Ocean Engineering and Technology
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• v.35 no.1
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• pp.13-23
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• 2021

Since the introduction of the mandatory energy efficiency design index (EEDI), several studies have been conducted on the maneuverability of waves owing to the decrease in engine power. However, most studies have used the mean wave force during a single cycle to evaluate maneuverability and investigated the turning performance. In this study, we calculated the external force in accordance with the angle of incidence of the wave width and wavelengths encountered by KVLCC2 (KRISO very large crude-oil carrier) operating at low speeds in regular waves using computational fluid dynamics (CFD). We compare the model test results with those published in other papers. Based on the external force calculated using CFD, an external force that varies according to the phase of the wave that meets the hull was derived, and based on the derived external force and MMG control simulation, a maneuvering simulation model was constructed. Using this method, a weather vaning simulation was performed in regular waves to evaluate the course-keeping ability of KVLCC2 in waves. The results confirmed that there was a difference in the operating trajectory according to the wavelength and phase of the waves encountered.

• Journal of Korean society of Dental Hygiene
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• v.17 no.5
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• pp.889-898
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• 2017

Objectives: This study was conducted in order to identify the various influencing factors of dental caries according to the socio-economic characteristics and oral health behaviors across the life cycle among Koreans. Methods: The data were extracted from the 6th Korea National Health and Nutrition Examination Survey (2013-2015) and a total of 4,871 subjects with ages of 7 and over were selected. The data were analyzed using SPSS 21.0 for ${\chi}^2$-test and multi-logistic regression. Results: Significant differences were observed in the socio-economic characteristics, health behaviors and in the dental caries across the life cycle. The influencing factors of DT includes the type of health insurance (p<0.05) in school aged & adolescence, Oral health examination/year (p<0.01), Residence (p<0.05) in early adults, type of health insurance (p<0.001), Oral health examination/year (p<0.001), use of oral hygiene products (p<0.01) in late Adults, Oral health examination/year (p<0.05) and Gender (p<0.05) in old age. Conclusions: This study suggests that dental health promotion can be enhanced by regular checkup. The government must provide the people with better quality of oral health care and promotion across the life cycle in the near future.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1759-1768
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• 2018

The energy density, power density and ohm resistance of battery change significantly as results of battery aging, which lead to decrease in the accuracy of the equivalent model. A parameter identification method of the equivale6nt circuit model with 3 R-C branches based on the test database of battery life cycle is proposed in this paper. This database is built on the basis of experiments such as updating of available capacity, charging and discharging tests at different rates and relaxation characteristics tests. It can realize regular update and calibration of key parameters like SOH, so as to ensure the reliability of parameters identified. Taking SOH, SOC and T as independent variables, lookup table method is adopted to set initial value for the parameter matrix. Meanwhile, in order to ensure the validity of the model, the least square method based on variable forgetting factor is adopted for optimizing to complete the identification of equivalent model parameters. By comparing the simulation data with measured data for charging and discharging experiments of Li-ion battery, the effectiveness of the full life cycle database and the model are verified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.166-169
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• 2004

A fatigue test was used to evaluate the fatigue life of an actual structure. The loaded state and the constraint condition of an actual structure must be same as the specimen in order to apply the test results to an actual structure by the specimen. The loaded state and constraint conditions can't be same as the specimen in the actual structure which is complicated. In order to reduce these differences, an actual structure test with a lot of frequencies is need to get a fatigue life curve. Therefore, ten sets of accelerated test units which attached unbalanced mass were composed in this study. Acceleration history about the vibration of an actual structure was acquired. Rainflow counting was used on acceleration history, and the life curve return formula was assumed. The return formula that damage satisfied `1' was acquired in a feedback process by the Miner's rule, which was the linear cumulative damage theory. A conservative fatigue life curve was determined with a return formula to have been presumed by each set. The fatigue life of regular rpm condition was calculated by these conservative fatigue life curves.

• Fashion & Textile Research Journal
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• v.17 no.2
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• pp.258-264
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• 2015

This study provides abasis for the development of high functional cycle wear with clothing comfort and fitness for highschool boy cyclists by a comparison of the somatotype of highschool boys cyclists and general highschool boys. This study directly measured 44 anthropometric targeted cyclists across Korea. "The sixth national standard physical survey" data targeted 16 to 18-year-old male adolescents; subsequently, anthropometric measurement data was provided by 766 people for research. Highschool boy cyclists used t-test to compare the differences in body type. The results in this study are follows. Highschool boys cyclists(compared to regular highschool boys) indicated a great somatotype stature and weight. The differences in the cervical height and the acromion height results of, cyclist appeared smaller. Cyclists angle of shoulder was smaller. The upper body of highschool boys cyclist was greater than the difference between chest breadth and bust breadth with along biacromion length. The waist front length of the cyclist was a short cycle ride upon the attitude of the streamlined. Highschool boy cyclists indicated that the muscles of the arm portion was more developed compared to general highschool boys. The lower body had less abdominal fat with a significantly developed thigh and calf.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.4
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• pp.183-193
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• 2008

Purpose: To research the changes of Skin Resistance Variability(SRV) over the period of ovarian cycle of healthy young women with normal and regular menstrual cycles using Oriental Medical Diagnose Autonomic system-3000 (OMD-3000). Methods: We measured SRV of 15 women who were working at O O Oriental Hospital from July to Oct. 2008. Each woman took the OMD-3000 test 8 times during 2 menstrual cycles. Each cycle consists of 4 phases-follicular phase, ovulation, luteal phase and menstruation. We analyse the data by SPSS 12.0 for windows. the one-way ANOVA by Repeated Measure(p<0.05). Results: 1. (1) The Factor AA means at zone 1 were 0.77$\pm$0.40, at zone 2 were 1.07$\pm$0.68, at zone 3 were 0.77$\pm$0.35, at zone 4 were 0.68$\pm$0.32, at zone 5 were 0.74$\pm$0.29, at zone 6 were 0.85$\pm$0.30, and at zone 7 were 0.74$\pm$0.29. The Factor AA means were lower than normal range at zone 1,3,4,5,6 and 7. The graph pattern of M shape was caused by the Factor AA means at zone 2 and zone 6 were higher than others. (2) The Factor AA means at zone 1 and zone 3 show abnormal regulation state. 2. During the menstruation. the Factor AA means were higher at zone 1,2 and 3 than other zones. During the ovulation, the Factor AA means were higher at zone 4,5,6 and 7 than other zones. Especially at the menstruation phase in zone 2 and at the ovulation phase in zone 6 tend to be highest means than other phases respectively. 3. However there were no significant difference of means during 4 ovarian phases in 7 zones except ovulation phase to luteal phase at zone 4(p = 0.013). Conclusion: The results suggest that changes of SRV during 4 menstrual cycles are not variables in reading 7-zone-diagnostic system. Further study will be needed.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.267-275
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• 2010

Quality management of an x-ray unit drastically differs according to the type of establishment of medical institutions. Many primary medical institutions have it, but they do not pay much attention to quality management. In the study, Gyeongbuk area has been divided into four zones from January 4, 2010 to September 3, 2010, and four places were designated by city. Among medical institutions located at a total of 16 sites, the target was 8 places with X-ray emission equipment 10 years or more in use as well as 8 places with X-ray emission equipment less than 10 years in use. The 5 essential items of quality control were tested. In the test that checked for equipment it was found that sites with X-ray emission equipment 10 years or more in use didn't have ground connection (6.25%) while all of them passed the current leak test. In the exposure dose reproducibility test 4 sites with X-ray emission equipment 10 years or more in use (25%) and 1 site with X-ray emission equipment less than 10 years in use didn't pass the test. In the KVp accuracy test 5 sites with X-ray emission equipment 10 years or more in use (31.25%) and 2 sites with X-ray emission equipment less than 10 years in use (12.5%) didn't pass the test. In the tube current and tube current amount test 3 sites with X-ray emission equipment 10 years or more in use (18.75%) and 1 site with less than 10 years in use (6.25%) didn't pass the test. According to the findings of the present research, quality control at medical institutions with X-ray equipment 10 years or more in use was poorer than medical institutions with X-ray equipment less than 10 years in use. In this regard, administrative and technical measures need to be taken as soon as possible. In addition, owners of medical clinics or unit managers need to raise awareness, and it is necessary to revise a regular test cycle every year or every two years if they have old equipment or if the equipment is not used on a frequent basis. And it is also important to provide regular educational programs for quality management.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.71-78
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• 2010

The existing capacitor-testers could only judge the condition of capacitor is normal or abnormal, and could not inform the real characteristics of the tested capacitors. In this research, it has designed the real-time observation of the new capacitor in charge and discharge tester for showing capacitor conditions and classification through wide voltages by regular cycle-tests. And proposed the quality classification algorithm of capacitors for more simple and practical, and approve them by test.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.11
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• pp.92-97
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• 2010

The object of this study is to investigate the definite method for pitting damaged surfaces. Pitting is a sort of fatigue damages and it is made by a repetitive load. For a judgment between damages or not, sensing vibrations of test equipment is simple. However, it is not only difficult to observe a growth of pitting but also impossible to detect the juncture of initial pitting. Therefore, a method for the pitting damaged area measuring technique was effectively implemented by Two Roller Machine. The change of surface damaged area was measured by an optical microscope in regular time and calculated by the use of dark and bright ratio of test specimens' pictures taken by optical microscope. In conclusion, S - N Curves gained by Failure rate - Cycle graph was led and the curves are able to be chosen as occasion demands for a failure area percentage.