• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.3
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• pp.233-243
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• 2014

The difference of mooring tension by type of buoy was investigated in the circulating water channel and the wave tank for deducting the most stable buoy from the current and the wave condition. 5 types of buoy made up of short cylinder laid vertically (CL-V), short cylinder laid horizontally (CL-H), capsule (CS), sphere (SP) and long cylinder (CL-L) were used for experiments. A mooring line and a weight were connected with each buoy. A tensile gauge was installed between a mooring line and a weight. All buoy's mooring tension was measured at the same time for the wave test with periods of 1.5~3.0 sec and wave heights of 0.1~0.3 m, and the current test with flow speeds of 0.2~1.0 m/sec. As a result, the order of tension value in the wave test was CL-H > CL-V > SP > CS > CL-L. In the current test CL-V and CL-H were recorded in the largest tension value, whereas SP has the smallest tension value. So it seems that SP buoy is the most effective in the location affected by fast current. CS is predicted to be suitable for a location that influence of wave is important more than that of current if practical use in the field is considered. And it was found that the difference of mooring tension among buoys in wave is related to the product of the cross sectional area and the drag coefficient for the buoy's bottom side in high wave height. The factor for the current condition was not found. But it was supposed to be related to complex factors like a dimension and a shape by buoy's posture to flow.

• Nutrition Research and Practice
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• v.14 no.1
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• pp.55-61
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• 2020

BACKGROUND/OBJECTIVES: Osteoporosis is characterized by low bone mass and results in vulnerability to fracture. Calcium and vitamin D are known to play an important role in bone health. Recently, potassium has been identified as another important factor in skeletal health. We examined the link between potassium intake and bone health among the Korean older adult population. SUBJECTS/METHODS: This retrospective, cross-sectional study included 8,732 men and postmenopausal women over 50 years old who completed the Korean National Health and Nutrition Survey (KNHANES) between 2008 and 2011. Potassium consumption was evaluated using a 24-hour recall method. Bone mineral density (BMD) was measured at three sites (total hip, femur neck, and lumbar spine) by dual-energy X-ray absorptiometry (DEXA). Multinomial logistic regression was used to examine the link between potassium intake and prevalence of osteoporosis and osteopenia, after controlling for potential confounding variables. RESULTS: The BMD of the total femur and Ward's triangle were significantly different according to the potassium intake among men (P = 0.031 and P = 0.010, respectively). Women in the top tertile for potassium intake showed higher BMD than those in the bottom tertile at all measurement sites (all P < 0.05). Daily potassium intake was significantly related to a decreased risk of osteoporosis at the lumbar spine in postmenopausal women (odds ratios: 0.68, 95% confidence interval: 0.48-0.96, P trend = 0.031). However, the dietary potassium level was not related to the risk of osteoporosis in men. CONCLUSION: Current findings indicate that higher dietary potassium levels have a favorable effect on bone health and preventing osteoporosis in older Korean women.

• Women's Health Nursing
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• v.12 no.3
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• pp.210-220
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• 2006

Purposes: This study examined the relationship between risk behaviors and sexual knowledge, sexual attitudes, and sexual experiences of male high school students. Method: A cross-sectional, descriptive study was conducted. Data were collected from 2 male high schools in metropolitan Gwangju. Five hundred forty-eight boys were enrolled in this study. Descriptive statistics, factor analysis, t-test or ANOVA, and Pearson's correlation were used for data analysis. Results: The mean sexual knowledge and sexual experience scores were relatively low, 0.60 out of 1 point, and 0.75 out of 4 points, respectively. Three attitude types of the students were identified: permissible, conservative and pleasure seeking attitude. The score of the permissible type was affected by the subjects' exposure to pornographic material. The score of the conservative type was affected by alcohol consumption and acquaintances with a heterosexual friend. The score of the pleasure seeking type was affected by their exposure to pornographic material, alcohol consumption, smoking, going to a video-room, and acquaintances with a heterosexual friend. There was a negative correlation between the permissible type and sexual knowledge, and a positive correlation between the conservative and pleasure seeking types and sexual experience. Conclusion: Male high school students who have been exposed to risk behaviors have a higher likelihood of indulging in sexual activity, and the pleasure seeking type appears to be related to sexual experience. An educational program may be needed to prevent risky behaviors and sexual experiences in male high school students considering their sexual attitude type.

• Women's Health Nursing
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• v.17 no.1
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• pp.77-87
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• 2011

Purpose: This study aimed to identify differences in contraception behavior and related factors between unmarried female and male. Methods: A cross-sectional survey design with a convenient sampling was used. From Seoul, 107 women and 96 men were recruited. A structured questionnaire was self-administered from July 14, 2008 to September 2, 2008. Results: The average ages of women and men were 26.9 and 27.8 years old, respectively. Fiftysix percent of women and 85.4% of men have experienced sexual intercourse. There were no differences between female and male in attitude toward contraception, subjective norm, and contraception behavior, while female had higher score of self-efficacy for contraception (p=.02) and intention of contraception (p=.02). There was positive correlation with subjective norm (r=.22, p<.05), self-efficacy (r=.53, p<.01) in male and attitude (r=.32, p<.05), selfefficacy (r=49, p<.01) in female. According to the result of multiple regression, the significant factor of contraception behavior was self-efficacy for both female (${\beta}$=.49, p=.00) and male (${\beta}$=.53, p=.00). Conclusion: To improve contraception behavior for unmarried female and male, it is necessary to develop proper sex education program to enhance self-efficacy for contraception. Adjusted education program by this result will contribute to increase sexual health for female and male.

• Women's Health Nursing
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• v.17 no.5
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• pp.463-473
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• 2011

Purpose: Cervical cancer can be prevented by regular cervical screening. Embarrassment has been reported as one important barrier to cervical screening uptake. The absence of appropriate instrumentation, however, has limited our understanding of the links between embarrassment and health care outcomes. The purpose of this study was to evaluate psychometric attributes of the uterine cervical cancer screening embarrassment questionnaire. Methods: A convenience sample for field study was recruited from four gynecological clinics in Gyeongju, Korea. Within a cross-sectional descriptive design, 339 women who had cervical screening completed self-administered measures of embarrassment including a visual analogue, general medical embarrassment, dispositional embarrassment, and Pap smear related negative emotion. Results: Rasch analysis of items demonstrated the evidence of one-dimensional construct and good 7-point rating scales functioning. Factor analysis revealed that uterine cervical cancer screening embarrassment was comprised of two domains-bodily manifestations and perceiving an undesirable social face. Construct validity was demonstrated by a high subscale-to-subscale correlation. Convergent and discriminant validity was evidenced by significant correlations with a 100 mm VAS scale, general medical embarrassment, and Pap smear related negative emotion. Known-group validity was established by comparing women with high versus low trait embarrassment. Both two sub-scales and overall scale demonstrated good internal reliability. Conclusion: The Uterine uterine cervical cancer screening questionnaire is a reliable and valid instrument suited to assessing the manifestations of embarrassment during screening. The use of instrument can be extended to understand the client's embarrassment undergoing health examinations which require the exposure of their private parts.

• Journal of Korean Academy of Psychiatric and Mental Health Nursing
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• v.27 no.4
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• pp.406-414
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• 2018

Purpose: The purpose of this study was to investigate the relationship between cell phone dependency and aggression in elementary school students with the mediating effect of leisure activities in South Korea. Methods: Data were cross-sectional in study design with 1,555 fourth grade elementary school students participating in the 4th-year Korean Children and Youth Panel Survey. Data analysis was performed using the SPSS/WIN 23.0 and AMOS 21.0 program. Results: Cell phone dependency has a significant effect on aggression, but it did not act as a control variable in the relationship between the protective factor, weekly book reading time and the amount of daytime play with aggression. Weekly entertainment time and weekly TV and video viewing time had a significant statistical effect on aggression, thus this study confirmed that cell phone dependency acts as a control variable in relation to aggression. Conclusion: As the entertainment time for elementary school students, the time spent watching TV and videos play a negative role, it is necessary to prepare a leisure activity management practice and strategies with an emphasis on entertainment time as well as, TV and video viewing as elementary school students' leisure activities for a healthy school life.

• Journal of East-West Nursing Research
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• v.25 no.2
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• pp.183-192
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• 2019

Purpose: This study aimed to examine the mediating effect of illness perception on the relationship between family function and health behavior of patients with risk factors for metabolic syndrome. Methods: This is a cross-sectional correlational study. Data were collected from 160 patients using self-administered questionnaires including the Illness Perception Questionnaire-Revised, Family APGAR, and the Health Behavior Scale. The data were analyzed using Pearson's correlation coefficients, independent t-test and multiple linear regression analysis by the SPSS 23.0 program. Results: Health behavior was significantly correlated with family function (r=.30, p<.001) and illness perception of controllability by treatment (r=-.21, p=.007). Family function was a significant predictor of health behavior and illness perception, and the influence of family function on health behavior was partially mediated by illness perception of controllability by treatment. Conclusion: The findings of this study indicate that family function is a critical factor affecting health behavior and illness perception, and illness perception of controllability by treatment mediates the influence of family function on health behavior. It is necessary to develop a psycho-cognitive intervention program for enhancing supportive family function and for modifying negative illness perceptions to improve health behavior in patients with risk factors for metabolic syndrome.

• Journal of the Korean Society of School Health
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• v.34 no.1
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• pp.62-75
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• 2021

Purpose: Smoking among adolescents is a critical healthcare concern that needs to be tackled with respect to not only intrapersonal and interpersonal factors but also socio-cultural factors. This study was to identify the smoking behaviors and amount of tobacco consumption among adolescents, and to investigate the factors associated with the behaviors and amount. Methods: A cross-sectional study was conducted based on the theory of triadic influence using a nationally representative secondary data set, the 2018 Korea Youth Risk Behavior Survey (N=60,040). The analysis was performed by dividing smoking behaviors into lifetime, current, and daily smoking, and smoking amount into light, moderate, and heavy smoking. Descriptive statistics and multinomial logistic regression analyses were conducted. Results: Overall, 8.2%, 3.2% and 3.4% of the adolescents were involved in lifetime, current, and daily smoking, respectively. In addition, 5.3%, 0.8%, and 0.6% of the adolescents were involved in light, moderate, and heavy smoking, respectively. The factor associated with smoking behaviors and the amount of tobacco consumed were gender, academic achievement, depression, living with family, close friend's smoking, violent victimization, household economic status, and school level (all ps<.05). Conclusion: A considerable number of adolescents are engaged in risky smoking behaviors and consume large amounts of tobacco. Adolescents who said yes to peer smoking, violent victimization, not living with their family, and depressive emotions were more likely to engage in risky smoking behaviors and consume large amounts of tobacco. Tailored interventions to decrease smoking should be planed and provided, while considering the school and home environment and individual needs of adolescents.

• Journal of Preventive Medicine and Public Health
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• v.54 no.4
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• pp.238-244
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• 2021

Objectives: Previous pandemics have demonstrated that several demographic, geographic, and socioeconomic factors may play a role in increased infection risk. During this current coronavirus disease 2019 (COVID-19) pandemic, our aim was to examine the association of timing of lockdown at the county level and aforementioned risk factors with daily case rate (DCR) in the United States. Methods: A cross-sectional study using publicly available data was performed including Americans with COVID-19 infection as of May 24, 2020. The United States counties with >100 000 population and >50 cases per 100 000 people were included. The independent variable was the days required from the declaration of lockdown to reach the target case rate (50/100 000 cases) while the dependent (outcome) variable was the DCR per 100 000 on the day of statistical calculation (May 24, 2020) after adjusting for multiple confounding socio-demographic, geographic, and health-related factors. Each independent factor was correlated with outcome variables and assessed for collinearity with each other. Subsequently, all factors with significant association to the outcome variable were included in multiple linear regression models using stepwise method. Models with best R² value from the multiple regression were chosen. Results: The timing of mandated lockdown order had the most significant association on the DCR per 100 000 after adjusting for multiple socio-demographic, geographic and health-related factors. Additional factors with significant association with increased DCR include rate of uninsured and unemployment. Conclusions: The timing of lockdown order was significantly associated with the spread of COVID-19 at the county level in the United States.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.689-698
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• 2021

The development of modern warfare detection technology is increasingly threatening the survivability of aircraft. Among them, IR-seeking missiles greatly affect the survivability of aircraft and are a main factor that reduces the success rate of aircraft missions. In order to increase aircraft survivability, studies on shape-modifying nozzles with added curvature are being actively conducted. In this study, we selected a double serpentine nozzle among shape-modifying nozzles to increase aircraft survivability. We then investigated the effects of the location of the maximum area change rate of the nozzle. It was confirmed that the location of the change rate of area affects the thrust and exit temperature of the nozzle. In addition, it was shown that the thrust penalty was reduced as the position of the change rate of the maximum area was located at the rear of the nozzle.