• Journal of the Korean institute of surface engineering
• /
• v.29 no.2
• /
• pp.81-92
• /
• 1996

The cementless fixation of bone ingrowth by porous coatings on artificial hip joint prostheses are replacing polymethylmethacrylate(PMMA) bone cement fixations. However, the major interests in the field of porous metal coating are environmental corrosivity accelerated by metal ion release, deterioration in the mechanical property of the coating, and the mechanical failure of the coatings as well as the substrate. Therefore, the selection of right materials for coatings and the development of porous coating techniques must be accomplished. Because of the existing problems in Ti and Ti alloys which are used extensively, this study is focused on the plasma spraying technique for coating on super stainless steel substrate. In order to determine the optimum conditions which satisfy the requirement for the porous coatings, under the plasma spraying, we selected the experimental parameters which extensively influenced on the characteristics of the coating through the pre-examination. Spray distance has been selected among 120, 160, and 200mm and primary gas flow rate among 70, 100, and 130 SCFH. Current and secondary gas($H_2$) flow rate was fixed at 400A, and 15 SCFH respectively. To understand the characteristics of the coatings, surface morphology, cross-sectional micro-structure, surface roughness, residual stress, and corrosion resistance were elucidated and the best conditions for the bone ingrowth improvement on artificial hip joint prostheses were found.

• Structural Engineering and Mechanics
• /
• v.76 no.3
• /
• pp.325-336
• /
• 2020

In this study, the continuous and discontinuous contact problems of functionally graded (FG) layer resting on a rigid foundation were considered. The top of the FG layer was loaded by a distributed load. It was assumed that the shear modulus and the density of the layer varied according to exponential functions along the depth whereas the the Poisson ratio remained constant. The problem first was solved analytically and the results were verified with the ones obtained from finite element (FE) solution. In analytical solution, the stress and displacement components for FG layer were obtained by the help of Fourier integral transform. Critical load expression and integral equation for continuous and discontinuous contact, respectively, using corresponding boundary conditions in each case. The finite element solution of the problem was carried out using ANSYS software program. In continuous contact case, initial separation distance and contact stresses along the contact surface between the FG layer and the rigid foundation were examined. Separation distances and contact stresses were obtained in case of discontinuous contact. The effect of material properties and loading were investigated using both analytical and FE solutions. It was shown that obtained results were compatible with each other.

• Journal of East-West Nursing Research
• /
• v.27 no.2
• /
• pp.166-176
• /
• 2021

Purpose: This study was conducted to assess the effect of household types on the occurrence of chronic diseases depending on gender and to identify the factors associated with chronic disease occurrence in one-person households. Methods: Multivariate logistic regression analysis was conducted using the data of 15,949 adults with the age of 19 years or older from the sixth Korea National Health and Nutrition Examination Survey (2013~2015). Results: For male, the risk of chronic disease occurrence was higher in one-person households than in multi-person households, and the same held true after adjusting for the confounding factors. For female, no significant relationship was found between household types and chronic disease occurrence. Factors associated with chronic disease occurrence were age, employment state, marital state, smoking, perceived stress, and depression in male, and age, employment state, physical activity, and obesity in female. Conclusion: It is necessary to monitor the disparity in health depending on household types in male. Additionally, providing a gender specific chronic disease prevention and health enhancement program is required.

• Journal of The Korean Society of Integrative Medicine
• /
• v.7 no.1
• /
• pp.57-64
• /
• 2019

Purpose : This study was implemented to identify the risk conditions influencing suicidal ideation in a nationally representative sample of elderly South Koreans. Methods : Data from 1,152 men and 1,581 women aged 65 years or older were gathered from the 2013 and 2014 Korea National Health and Nutrition Examination Survey VI. All analyses were performed using SPSS. To determine significant correlations between risk condition and suicidal ideation, a t-test was used. Results : There were differences in suicidal ideation according to the following individual factors: age, educational background, marital status, economic activity, recognition of stress, experience of depression, and economic status. There were differences in suicidal ideation according to the following health-related factors: subjective health status, EQ-5D (EuroQoL-5 Dimensions), hours of sleep, and BMI. There were also differences in suicidal ideation according to the following disease-related factors: HTN, COPD, asthma, stroke, depression and osteoarthritis. Conclusion : The findings indicate that broad intervention programs should be distributed to prevent suicidal ideation. It is also recommended that programs be developed in a way that can help manage the variables identified in this study. Furthermore, follow-up studies should be conducted to verify the program.

• Journal of Korean society of Dental Hygiene
• /
• v.19 no.4
• /
• pp.577-589
• /
• 2019

Objectives: The purpose of this study was to investigate the effects of general and oral health on quality of life in the elderly living alone and with family. Methods: We analyzed data from the $6^{th}$ Korea National Health and Nutrition Examination Survey. Distribution of the elderly living alone and with family based on the general characteristics and general and oral health was analyzed using complex-sample chi-square tests. Multiple logistic regression was used to analyze the factors affecting quality of life by calculating the 95% confidence intervals. Results: In the elderly living alone, the quality of life significantly correlated with restriction of activity, perceived general and oral health status, perceived stress, and speech difficulties. Further, in the elderly living with family, lower quality of life significantly correlated with restriction of activity, perceived health status, walking days per week, life time smoking history, Community Periodontal Index, and chewing and speech difficulties. Conclusions: The elderly are concerned with self-maintenance of general and oral health. Therefore, systematic policies related to health services need to be developed and operated at the national level. It is especially necessary to take social interest in the elderly living alone and a more continuous and professional approach in their health care.

• Journal of Preventive Medicine and Public Health
• /
• v.52 no.2
• /
• pp.92-100
• /
• 2019

Objectives: Young adulthood represents a critical developmental period during which the use of tobacco may begin or cease. Furthermore, differences in smoking behaviors between younger (aged 18-24 years) and older (aged 25-34 years) young adults may exist. This study aimed to characterize patterns related to current smoking in younger and older young adults. Methods: This study used data acquired from the Sixth Korea National Health and Nutrition Examination Survey conducted from 2013 to 2014. A total of 2069 subjects were categorized as younger (712 subjects) and older (1357 subjects) young adults. The chi-square test was used to assess the relationships between smoking status and socio-demographic, health-related, and smoking-related factors. Multivariable logistic regression models were constructed to assess the factors affecting current smoking in these age groups. Results: The current smoking prevalence was 18.3% among the younger young adults and 26.0% among the older young adults. Sex, education level, occupation, perceived health status, alcohol consumption, and electronic cigarette use were related to current smoking in both age groups. Secondhand smoke exposure at home and stress levels showed significant relationships with smoking in younger and older young adults, respectively. Conclusions: Strong correlations were found between the observed variables and smoking behaviors among young adults. Determining the factors affecting smoking and designing interventions based on these factors are essential for smoking cessation in young adults.

• Journal of Korean Public Health Nursing
• /
• v.33 no.1
• /
• pp.20-32
• /
• 2019

Objectives: This study identified biopsychosocial factors associated with metabolic syndrome among Korean men and women aged over 40 years. Methods: Secondary data from the 2010-2016 Korean National Health and Nutrition Examination Survey were used for this study. Based on the biopsychosocial model, psychosocial factors (stress, depression, smoking, binge alcohol consumption, physical activity) were assessed with control of biomedical (age, body mass index, family history of hypertension, dyslipidemia, type 2 diabetes mellitus, and cardiovascular disease) and biosocial factors (educational level and economic status). Data from 8,624 men and 7,321 women were analyzed by logistic regression analysis using a complex sample procedure. Results: Among men, current or past smoking habits (Adjusted Odds Ratio [AOR]: 1.349; 95% Confidence Interval [CI]: 1.155-1.575, p<.001) and binge alcohol consumption (AOR: 1.570, CI: 1.389-1.774, p<.001) were associated with metabolic syndrome. In addition, moderate (AOR: 1.205, CI: 1.038-1.400, p=.014) and low levels of physical activity (AOR: 1.296, CI: 1.109-1.514, p=.001) were associated with metabolic syndrome. Among women, low level of physical activity (AOR: 1.276, CI: 1.017-1.602, p=.036) was associated with metabolic syndrome. Conclusion: Gender specific interventions such as encouraging physical activity and prevention of smoking and excessive alcohol drinking are important to prevention of metabolic syndrome.

• Research in Community and Public Health Nursing
• /
• v.32 no.2
• /
• pp.131-139
• /
• 2021

Purpose: In adults with chronic diseases, unmet healthcare needs are likely to increase the risk of worsening the illness and complications. This study was conducted to explore factors affecting unmet healthcare needs among adults with chronic diseases. Methods: A cross sectional study was performed using the data from the seventh Korea National Health and Nutrition Examination Survey (KNHANES VII), 2016-2017. The sample of this study consisted of 6,104 adults with chronic diseases. The data were analyzed by Rao-Scott 𝑥² test and logistic regression using complex samples analysis. Results: The proportion of subjects who experienced unmet healthcare needs was 10.9% of adults with chronic diseases. The factors affecting unmet healthcare needs of adults with chronic diseases were age, gender, employment status, household income, subjective health status, activity limitation, and perceived stress. Conclusion: The findings of this study suggest that various factors may be associated with their unmet healthcare needs. Finally, the development of strategies to reduce unmet healthcare needs for people with chronic diseases should consider the associated factors presented in the study.

• Nuclear Engineering and Technology
• /
• v.53 no.2
• /
• pp.466-473
• /
• 2021

Fire protection is one of important issues to ensure safety and reduce risks of nuclear power plants (NPPs). While robust programs to shut down commercial reactors in any fires have been successfully maintained, the concept and associated regulatory requirements are constantly changing or strengthening by lessons learned from operating experiences and information all over the world. As part of this context, it is necessary not only to establish specific fire hazard assessment methods reflecting the characteristics of research reactors and educational reactors but also to make decisions based on advancement encompassing numerical analyses and experiments. The objectives of this study are to address fire simulation in the control room of an educational reactor and to discuss integrity of digital console in charge of main operation as well as analysis results through comparison. Three electrical fire scenarios were postulated and twenty-four thermal analyses were carried out taking into account two turbulence models, two cable materials and two ventilation conditions. Twelve supplementary thermal analyses and six subsequent structural analyses were also conducted for further examination on the temperature and heat flux of cable and von Mises stress of digital console, respectively. As consequences, effects of each parameter were quantified in detail and future applicability was briefly discussed. On the whole, higher profiles were obtained when Deardorff turbulence model was employed or polyvinyl chloride material and larger ventilation condition were considered. All the maximum values considered in this study met the allowable criteria so that safety action seems available by sustained integrity of the cable linked to digital console within operators' reaction time of 300 s.

• Journal of muscle and joint health
• /
• v.31 no.1
• /
• pp.53-63
• /
• 2024

Purpose: This study aimed to determine the prevalence of dizziness in adults and to identify factors associated with dizziness. Methods: This cross-sectional study used secondary data from the Eighth Korea National Health and Nutrition Examination Survey. Participants included 10,265 older adults aged≥40 years. Data were analyzed using descriptive statistics, the chi-squared test, and multinomial logistic regression with the SPSS/WIN 27.0 program. Results: The prevalence of dizziness was 26.2%, with 20.9% reporting episodic dizziness and 5.3% reporting chronic dizziness. Compared to that noted in the control group participants without dizziness, the risk of episodic or chronic dizziness was higher in women and in participants with older age, low education level, low income level, high perceived stress level, depression, tinnitus, and occupational noise exposure. Moreover, the risk of chronic dizziness was higher among those with a body mass index of <25 kg/m², stroke, cardiovascular disease, or severe hearing loss. Conclusion: The study underscores the need to comprehensively identify risk factors associated with dizziness and to develop interventions to prevent and manage the occurrence and chronicity of dizziness in the general population.