• Journal of Ocean Engineering and Technology
• /
• v.29 no.1
• /
• pp.28-33
• /
• 2015

The icebreaking research vessel ARAON had her second ice trial in the Arctic Ocean from July 16 to August 12, 2010. In this study, the ice loads measured during the “general” operation and “ice breaking” operation in ice-covered waters were analyzed and compared. Whereas the “general” operation stands for the voyage in the water partially covered by ice, the “ice breaking” operation involved substantial ice floes for the ice breaking performance test. Based on the measured data, comparisons of the relationship between the ship speed and ice load, and between the locations of strain gauges and ice loads were investigated. Peak stresses higher than 20 MPa were found. The longitudinal and vertical correlations between the measurement location and ice load were analyzed, and the probability of peak stress was calculated. As a result, the probability function for higher ice loads during both operation modes was expressed in an exponential and power forms.

• ETRI Journal
• /
• v.39 no.4
• /
• pp.467-479
• /
• 2017

This study examines how the characteristics of cooperative research and development (R&D) projects in the public domain impact information and communication technology (ICT) convergence. Based on the analysis of 416 cooperative R&D projects under the ICT-based industry convergence R&D program in Korea, the study finds that the characteristics of cooperative R&D projects significantly impact ICT convergence. Moreover, the participation of public research institutes and universities is critical for ICT convergence compared with that of firms. However, in firm-to-firm cooperation, the participation of small and medium enterprises contributes to cross-sectional convergence, while the participation of large firms leads to overall and longitudinal convergence. R&D inputs such as the number of partners and government subsidies exhibit an inverted U-shaped relationship (negative quadratic effect) with technology convergence. Project duration and homogeneous partners are also critical factors for ICT convergence. The results indicate several implications and guidelines on how to effectively organize cooperative R&D projects to facilitate technology convergence.

• Journal of Preventive Medicine and Public Health
• /
• v.38 no.3
• /
• pp.267-275
• /
• 2005

Evidence on the relation of socioeconomic position (SEP) with health and illness is mounting in South Korea. Several unlinked studies and individually linked studies (longitudinal study) showed a graded inverse relationship between SEP and mortality among South Korean males and females. Based on the mortality relative ratios by occupational class reported in the published papers of South Korea and western countries, the magnitude of the socioeconomic inequality in mortality in South Korea seems to be similar to or even greater than that in western industrialized countries. A potential contribution of health related selection, health behaviors and psychosocial factors to explain this socioeconomic inequality in mortality was discussed. It was suggested that early life exposure measures would demonstrate a greater ability to explain socioeconomic inequalities in all-cause mortality than the above pathway variables in South Korea. This is based on the cause-specific structure of mortality among the South Korean population who have a relatively greater proportion of stomach cancer, hemorrhagic stroke, liver cancer and liver disease, and tuberculosis, which share early life exposures as important elements of their etiology, than western countries. However, the relative contribution of early and later life socioeconomic conditions in producing socioeconomic inequality in health may differ according to the outcome, thus remains to be investigated.

• The korean journal of orthodontics
• /
• v.10 no.1
• /
• pp.81-93
• /
• 1980

The interrelationships between growth rates (and size) of the selected cranifacial dimensions and body dimensions (height and weight) were investigated in the longitudinal data of primary school children from 6 to 11 years of age. The data were obtained from serial cephalometric radiographs and health record which were taken at one year interval. Regression analyses were used to analyze the data. The main concludions might be summarized as follows; 1. Size relationships between body height (and weigh) and S-Gn, posterior facial height (s-Go), total mandibular length (Ar-Gn) showed high significant correlation, but no association between body height, weight and anterior cranial base length (S-N). 2. Correlation coefficients between facial dimensions and body height (and weight) were getting lower with age increase. 3. At all age groups, significant prediction equation for some facial dimensions with body height and weight were obtained. 4. In this sample, the growth rates of facial dimensions and body height and weight showed almostly constant during this age period and the growth rate of body height and weight of girls was exceeded that of boys. 5. A relatively high degree of variation between individuals existed in the sample. 6. A positive correlation was found for the relationship between the growth rates of facial dimensions and those of body height (and weight) in boys and girls, but was not found in total samples.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.13 no.1
• /
• pp.159-171
• /
• 2017

The purpose of this study is to investigate the effects of e - commerce technology characteristics and personal values on purchasing behavior by information security importance. The results of the empirical study that examined the university students in 2006 and 2016 are as follows. First, personal value is centered on personal values, such as self - esteem and self - esteem in 2006. In 2016, however, personal values such as self - fulfillment and personal relationship with others are important. Transactional ease and product service serve as the main value of the fun and pleasure of life, but the sense of accomplishment as the core value of information protection. Second, the technical characteristics of e-commerce are as follows. In terms of ease of transaction and product service, technology characteristics are simplified and directly effected over time. On the other hand, information protection works very closely with individual value, There was a strong tendency to enjoy benefits. Especially in 2006, if you want to enjoy transactional convenience through transaction information security or benefit from product service, it has been changed to recognize the importance of information security through payment in 2016.

• Health Policy and Management
• /
• v.23 no.2
• /
• pp.162-175
• /
• 2013

Background: The purpose of this study was to analyze the association between social support, psychosocial factors, and health behaviors of old adults in korean society. Methods: The data which was used in this study was extracted from the second wave of the Korean longitudinal study of aging in 2008. A total of 3,978 elderly aged 65 years or older were included in this study. We conducted $X^2$-test, t-test for the elderly health behavior in accordance with their social support and psychosocial factors. Also, multivariate logistic regressive analysis was performed in order to find how degree social support and psychosocial factors are associated with health behavior after adjusting sex, age, smoking (alcohol drinking), and other significant variables. The data was processed by SAS ver. 9.1 and Stata SE ver. 11. Results: Social support in older adults was significantly associated with lower smoking, alcohol drinking, exercise, and eating habit. Also, psychosocial factors were positively associated with smoking, alcohol drinking, regular exercise, and eating habit. Conclusion: health behaviors of old adults are likely to be vulnerable to social support and psychosocial factors. To increase effectiveness of the health policy for the elderly in Korea, it is important to adapt new strategy to include the empowerment of elderly's social networks, policy support to enhance subjective expectation, and life satisfaction.

• Journal of Korean Public Health Nursing
• /
• v.30 no.1
• /
• pp.136-148
• /
• 2016

Purpose: Patterns of traditional medicine (TM) utilization vary depending on culture, historical significance, and regulations. We seek to understand how socio-demographic factors are related to TM use in Korea. Methods: The longitudinal cohort survey data of the Korea Health Panel (2008-2012) were used for the analysis. Information on TM included questions on 4 types of TM therapies used in South Korea (e.g., acupuncture, moxibustion and cupping, herbal therapies, and massage using hand). To adjust clustering across multiple observations per individual, individual random effects were used in the multivariate analysis. All analyses were performed using Stata 11.0. Results: A majority of Koreans (60%) used WM only during a year, and few people used TM only. Among TM users, most (93%) used it along with WM and 8% used TM only. Our regression analysis showed that female, age 34-64, low-educated, and sicker people were more likely to use TM. Conclusion: This study provides evidence on the relationship between TM utilization and socio-demographic factors.

• Magazine of the Korea Concrete Institute
• /
• v.10 no.6
• /
• pp.233-240
• /
• 1998

A rational expression, developed to predict the shear strength of reinforced concrete beams, is derived from the relationship between shear and the rate of change of bending moment along a beam coupled with experimental findings for the arch action. The proposed ultimate shear strength equation, arising from analytical premises and then calibrated with experimental data, is a similar form to the ACI 318 equation derived mainly from empirical approach. The proposed equation depends on the concrete compressive strength, amount of longitudinal steel content, and the shear span-to-depth ratio, and rationally reflects the shear resistance mechanism of combined beam action and arch action in reinforced concrete beams. The proposed equation applied to existing test data and the results were compared with those predicted by the ACI 318 equation and the Zsutty's equation.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2005.06a
• /
• pp.311-314
• /
• 2005

To evaluate the acute effects of fine particles on pulmonary function, a longitudinal study was conducted. This study was carried out for the schoolchildren(3rd and 4th grades) living in Inner-Mongolia, China. 113 Chinese children were asked to record their daily levels of peak expiratory flow rate(PEPR) using portable peak flow meter(mini-Wright) for 40 days and 3 time everyday(12 April 2004 to 21 May 2004). The atmospheric concentration of fine particles in study area was also determined everyday during same period. The relationship between dailypeak expiratory flow rate(PEFR) and fine particle levels was analyzed using a mixed linear regression models including gender, age, height, the presence of respiratory symptoms, and daily average relative humidity as extraneous variables. The analysis showed that the increase of fine particle concentrations was negatively associated with the variability in PEPR. The IQR(inter-quartile range) increments of $PM_{10}$ or $PM_{2.5}(66.0{\mu}g/m^3$ and $118.9{\mu}g/m^3$, respectively) were also shown to be related with 1.422L/min(95% Confidence intervals: 0.270 ${\sim}$ 2.574) and 1.214L1min(95% Cl: 0.010 ${\sim}$ 2.418) decline in PEFR.

• Journal of Labour Economics
• /
• v.32 no.2
• /
• pp.1-25
• /
• 2009

Using the 2006 Korean Longitudinal Study of Ageing, this paper investigates the effect of sibling size on children's educational attainment. OLS estimation results show a negative relationship between the number of children and their educational attainment, which confirms the trade-off between child quantity and quality. However, estimation results using the first child's sex as an instrument for sibling size, show no evidence of a quantity-quality trade-off. Our findings suggest that the adverse effect of a larger sibling size on per-child investment in education can be mitigated by other factors such as peer effect.