• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.130-137
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• 2018

In long freight trains, there is a brake time delay in the neighboring freight cars that causes damage and fractures of couplers, especially the knuckle of them. If there is a problem for couplers in the cars, this could cause a derailment and lead to damage of human life and property damage. In this study, maximum forces on the couplers are studied when a long freight car brakes, with brake delay time and coupler gap. We have made a dynamic model of 50 freight cars and couplers, applying contact between couplers and a characteristic curve for expressing force and displacement of buffers with SIMPACK, a multi-body dynamics program. We use EN 14531-2 from the British Standards Institution, a standard of freight car brakes for the verification of the dynamic model. We also use a simplified method to analyze the dynamic model of 50 freight cars. With changing coupler gap and brake delay time, we do comparative analysis with AAR M-201 from the Association of American Railroads, a standard of AAR couplers. From this result, we find that the standard on fatigue limit is satisfied, such that the brake delay time is within 0.06 second if the coupler gap of the AAR coupler is within 20 millimeters.

• Nuclear Engineering and Technology
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• v.38 no.6
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• pp.459-482
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• 2006

A geochemical approach to the long-term safety of waste disposal is discussed in connection with the significance of actinides, which shall deliver the major radioactivity inventory subsequent to the relatively short-term decay of fission products. Every power reactor generates transuranic (TRU) elements: plutonium and minor actinides (Np, Am, Cm), which consist chiefly of long-lived nuclides emitting alpha radiation. The amount of TRU actinides generated in a fuel life period is found to be relatively small (about 1 wt% or less in spent fuel) but their radioactivity persists many hundred thousands years. Geological confinement of waste containing TRU actinides demands, as a result, fundamental knowledge on the geochemical behavior of actinides in the repository environment for a long period of time. Appraisal of the scientific progress in this subject area is the main objective of the present paper. Following the introductory discussion on natural radioactivities, the nuclear fuel cycle is briefly brought up with reference to actinide generation and waste disposal. As the long-term disposal safety concerns inevitably with actinides, the significance of the aquatic actinide chemistry is summarized in two parts: the fundamental properties relevant to their aquatic behavior and the geochemical reactions in nanoscopic scale. The constrained space of writing allows discussion on some examples only, for which topics of the primary concern are selected, e.g. apparent solubility and colloid generation, colloid-facilitated migration, notable speciation of such processes, etc. Discussion is summed up to end with how to make a geochemical approach available for the long-term disposal safety of nuclear waste or for the performance assessment (PA) as known generally.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.22 no.1
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• pp.1-8
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• 2022

Long-chain fatty acid oxidation disorders (LC-FAOD) are an autosomal recessive inherited rare disease group that result in an acute metabolic crisis and chronic energy deficiency owing to the deficiency in an enzyme that converts long-chain fatty acids into energy. LC-FAOD includes carnitine palmitoyltransferase type 1 (CPT1), carnitine-acylcarnitine translocase (CACT), carnitine palmitoyltransferase type 2 (CPT2), very long-chain acyl-CoA dehydrogenase (VLCAD), long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), and trifunctional protein (TFP) deficiencies. Common symptoms of LC-FAOD are hypoketotic hypoglycemia, cardiomyopathy, and myopathy. Depending on symptom onset, the disease can be divided as neonatal period, late infancy and early childhood, adolescence, or adult onset, but symptoms can appear at any time. The neonatal screening test (NBS) can be used to identify the characteristic plasma acylcarnitine profiles for each disease and confirmed by deficient enzyme analysis or molecular testing. Before introduction of NBS, the mortality rate of LC-FAOD was very high. With NBS implementation as routine neonatal care, the mortality rate was dramatically decreased, but severe symptoms such as rhabdomyolysis recur frequently and affect the quality of life. Triheptanoin (Dojolvi^®), the first drug for pediatric and adult patients with molecularly confirmed LC-FAOD, has recently been approved by the US Food and Drug Administration in 2020. In this review, the diagnosis of LC-FAOD and treatment including triheptanoin are summarized.

• Journal of Families and Better Life
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• v.18 no.2
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• pp.1-14
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• 2000

The purpose of this study is to compared the length of working hours and its effects on family life for Korean and Japanese full-time working couples. For this study, the survey used structured questionnaires and time diaries(one weekday and holiday), and the data were collected in the fall of 1995. A subsample of full-time working couples, 82 couples from Seoul and 79 couples from Tokyo, was used for the purpose of this study. The major findings are as follows; 1) On average, the weekday working hours of Korean husbands were longer than Japanese husbands(11 hours 31 minute, 10 hours 52 minutes a day, respectively). Wives in both countries worked almost identical lengths of time (9 hours 2 minutes in Korea and 8 hours 42 minutes in Japan). Working hours of husbands were longer than those of wives in both countries. Husbands' overtime. Almost (90%) of our Korea sample worked 6 days or 5 1/2 days per week, however the majority (69%) of our Japanese sample worked only 5 days per eek. 2) More Korean husbands and wives reported that their family life was constrained by wives working hours than their Japanese counterparts did. 3) All wives in both countries reported that the husbands long working hours has effects on quality family time. Korean wives perceived that their working hours had effects on time spent on child care, however Japanese wives perceived that their working hours affected their personal time and housework time. Korean husbands agreed with their wives working hours negatively affected their personal leisure time. Japanese husbands reported that their working hours negatively affected their sleeping time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1051-1055
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• 1997

Hot forging is widely used in the manufacturing of automotive component. The mechanical, thermal load and thermal softening which is happened by the high temperature die in hot forging. Tool life of hot forging decreases considerably due to the softening of the surface layer of a tool caused by a high thermal load and long contact time between the tool and workpieces. The service life of tools in hot forging process is to a large extent limited by wear, heat crack, plastic deformation. These are one of the main factors affecting die accuracy and tool life. It is desired to predict tool life by developing life prediction method by FE-simulation. Lots of researches have been done into the life prediction of cold forming die, and the results of those researches were trustworthy, but there have been little applications of hot forming die. That is because hot forming process has many factors influencing tool life, and there was not accurate in-process data. In this research, life prediction of hot forming die by wear analysis and plastic deformation has been carried out. To predict tool life, by experiment of tempering of die, tempering curve was obtained and hardness express a function of main tempering curve.

• Journal of Families and Better Life
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• v.24 no.3 s.81
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• pp.43-58
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• 2006

The purpose of this study is to analysis the effects of religious activities on adolescents' life satisfaction. For this purpose, we surveyed the general trend of adolescents' religious activities and life satisfaction as well as life satisfaction according to demographical variables. In addition, this study analyzed adolescents' life satisfaction according to variables related to individual adolescents' religious activities and to parents' religious activities. The analyses of the results are as follows. First, since the childhood, adolescents have been participated in religious activities habitually or by enforcement or encouragement of their acquaintances. However, most adolescents think that the main purposes of their religious activities are a receiving grace and self-growing. So, they are willing to participate in worship service and spiritual training camp. Second, adolescents' life satisfaction was high when they got a high grade in school or they felt their health condition is good. The life satisfaction of adolescents who belong to economically high class families and whose fathers were college graduates or above is high. Third, the facts that effect on adolescent's life satisfaction are not how long they spend their time on religious activity, but the contents, motives and purposes of religious activities and satisfaction with religious activities. Fourth, adolescents' life satisfaction was high when their parents have same religion to them and their fathers participated in religious activities and their mothers did not participate in religious activities.

• Journal of Korean Physical Therapy Science
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• v.9 no.3
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• pp.31-49
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• 2002

The purpose of this study was to investigate discomforts and sexual life and to identify the relation between the discomforts and sexual life with low back pain. The data were collected from March 2 through July 31, 2001. Four hundred forty-two questionnaires were returned (response rate=88.0%). Analysis of the data was done with SPSS PC+ and use descriptive statistics, $x^2$-test, t-test, ANOVA. regression. The statistics shows that over than 80% of the adults experienced lumbago at least one time in their life, and Back pain is known as one of the most common complaints made by the patients of all ages in the general hospital or local medical clinics throughout. However, in certain case it leads to a chronic condition which can cause a great deal of problems in management and in financial burden to individuals and society. The result of this study was summarized as follows: 1) It appeared that regarding the distribution of gender, male was the higher(63.6%) then that of female, the portion of forties was 28.5%. Sitting for long time was 23.1% in men and 21.7% in women. Unknown reason including sexual behaviour was 12.9% in men and 15.5% in women. Patients treated medicine and physical therapy were 36.4%. In level of educational background, the rate of high school was 31.0%, technical college was 28.5%. The highest proportion by occupation was 18.3% of office workers, occupation posture was 41.9% of sitting. 2) Men(26.0%) and most of women(34.8%) were not satisfied in the explanation satisfaction rate of sex life concerned disease. 23.8% in men and 23.6% in women considered flexibility of waist good. Man(33.3%) and most of woman(35.0%) considered that Health education is necessary. 32.7% in men and 27.3% in women did't mind educator is whoever. Preventing of lower back pain(LBP) and proper Health education of sex life are demanded in daily life. 3) 58.0% of man and 64.0% of woman mostly had a posture which is man over woman. 28.5% in men and 27.8% in women considered that proper information finding of LBP and sex life was very few and few. 37.7% in men and 42.7% in women have acquired information about sex life flung their friends. 4) The number of sex life was decreased from 2.96 0.98 to 2.61 1.63 and also the time of sex life was decreased from 3.65 1.89 to 226 1.64. The satisfaction rate of sex life changed from 3.60 0.86 to 2.77 1.10. In the number of sex life, The non correct group was 2.62 1.91 and the correct group was higher in 2.68 1.65. In the time of sex life, The non correct group was 2.02 1.47 and the correct group was higher in 229 1.65. The satisfaction rate of sex life was 2.76 0.86 in non correct group and 2.88 1.10 in correct group. So there was a difference. 5) In the satisfaction rate of sex life, Men who have a lower back pain were higher than women and no attack group was higher than attack group. As they had many sex life, the satisfaction rate was higher significantly in statistics. As the time of sex life was short, the satisfaction rate was lower significantly in statistics. As the age was low, the demand rate of Health education was high and as means of patient who had a lower back pain was high, the demand rate of Health education was high. As the patient who had a lower back pain had a long married life, the demand rate of Health education was high and as education level was high, the demand rate of Health education was high. It is necessary to provide patients with conservative treatment, educational teaching, and training to prevent further injuries in the future. In general, it is important to educate the public how to prevent back injuries and how to treat themselves in an onset period to prevent further injuries sliding into a chronic state. Sexuality is an integral part of normal and healthy relationships, but patients are unable to enjoy sex because they are riot able to get into a comfortable position due to back pain. Many conditions of the spine can make certain positions uncomfortable. Health educator should make the education program of the discomforts and the sexual pattern for low back pain in workplace and/or hospital. Further study Is needed on how to integrate the educational program on sexuality into the total rehabilitation program.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.829-835
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• 2016

Electro-Mechanical Actuator installed on the aircraft plays a key role in an aircraft's flight control through flight control computer. Reliable prediction of the actuator is important for the aircraft. To estimate the lifetime of a product, it is necessary to test full target life. However, it is very difficult to perform it due to the long life time of actuator but short period of development time with increasing cost. Therefore, accelerated life test has been used to reduce the test time for various reasons such as reducing product's development cycle and cost. In this paper, to predict the lifetime of the actuator, we analyzed the flight profile of aircraft and adapted the method of accelerated life test in order to accelerate failure modes that might occur under user conditions. We also set up an endurance test equipment for validating the demanded lifetime of an actuator and performed accelerated life test.

• Journal of Family Resource Management and Policy Review
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• v.19 no.3
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• pp.121-142
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• 2015

The purpose of this study is to resolve the factors that affect happiness levels and leisure life satisfaction of middle-class and to find way to incorporate them into policy. In this study, a status analysis on leisure life and One-Way ANOVA conduct a study on leisure resource and income levels that affect the happiness level and leisure life satisfaction. To recap briefly, to reduce the social and cultural polarization caused by economic disparity and to promote leisure life satisfaction and happiness level is possible quantitative-qualitative growth and maturation of middle class. The most important thing here is increasing in leisure time and leisure costs that consumed in real leisure life. In other words, leisure life satisfaction and happiness levels in the middle class has seen a significant difference in depending on whether and how much to spend on leisure time and cost, rather than differences of the monthly average household income. More particularly, analysis results seem to hoping of the extra leisure costs about 50,000 won per person and increasing the leisure time on weekdays and long weekend holiday. Above all, It is important to redefine the middle class that meets the recognition of the people and it should reflect government policy. Ultimately, The state of the socio-economic-welfare policies will be further expanded in the direction for the middle class, thinking of themselves as middle class and leading national consciousness.

• Asian Oncology Nursing
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• v.8 no.1
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• pp.50-60
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• 2008

Purpose: The purpose of this study was to compare Quality of life (QOL) in type and time after Hematopoietic stem cell tansplantation (HSCT) for patients with hematologic cancer. Method: This study was cross-sectional. The autologous recipients was 120, the allogeneic recipients was 237. The obtained data were analyzed using T-test, One-way ANOVA, Scheffe's test. Results: No significant differences were total QOL between the autologous and allogeneic recipients. But the autologous recipients reported better status than the allogeneic recipients in physical domain, especially 1-3 yr after HSCT. There was poorer QOL of 1-3 yr compared to 1 yr after HSCT in physical, psychological and social domain between the two groups. QOL in time after HSCT of the autologous recipients was significance differences in psychological, social domain. And QOL in time after HSCT of the allogeneic recipients was significant differences in physical, psychological and social domain. Conclusions: QOL of recipients undergoing HSCT is recovered beyond 3 yr point. Accordingly, long term care and service is essential to recipients undergoing HSCT. And further studies with a longitudinal design are necessary.