• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.2
• /
• pp.329-338
• /
• 2018

This study was conducted to examine musculoskeletal disorder and analyze the effects of musculoskeletal pain control and self-efficacy on musculoskeletal disorders in dental hygienists. Material and Methods; 483 dental hygienists residing in Gwangju were collected by the convenience sampling method and the self-administered questionnaire survey was conducted. Frequency analysis, crosstab analysis, t-test, and multiple logistic regression analysis were used for analysis. Results: the prevalence of musculoskeletal pain among subjects was 83.9% for the prior year, with 29.8% of patients being afflicted by musculoskeletal disorders. The factors influencing musculoskeletal disorders were musculoskeletal pain resolution. For pain resolution, the odds ratio of musculoskeletal disorders of the group who answered treatment in a hospital, an Oriental medicine clinic, or a pharmacy was 0.22 (95% confidence interval, 0.14-0.34) compared with the group who answered sick leave or task change, suggesting a negative relationship. These findings indicate that people with musculoskeletal disorders were not treated in the hospital, Oriental medicine clinic, or pharmacy. Therefore, it is necessary to improve medical management (oriental medicine, intravenous injection or medication, heat therapy or cryotherapy, steroid treatment, counseling, endovascular treatment using spinal cord stimulation, physical therapy, stretching, rehabilitation, and manual therapy) and job environment and to make a good approach to the prevention of musculoskeletal disorders to control dental hygienists' musculoskeletal pain.

• Journal of the Korea Convergence Society
• /
• v.10 no.10
• /
• pp.267-274
• /
• 2019

The purpose of this study was to investigate the relationship between parenting attitude and child development. For this purpose, a survey was conducted to parents and children who visited child development centers and child-related welfare institutions located in Seoul and the Seoul metropolitan area. Total 230 pieces of survey papers were prepared, and 183 of them - except for 47 copies which were judged to be unreliable were used for the test analysis. Data analysis was performed using SPSS version 18.0 and descriptive statistical analysis was performed to analyze general characteristics of the subjects. In order to analyze the parenting attitude and developmental relationship of the children, the regression analysis was performed. Parents' parenting attitude - especially pressure and excessive expectation were found to have an effect on self-ridicule behaviors of children, and supervision and excessive expectation were found in small muscle exercise. Achievement pressure and excessive expectation were also the main variables in expression language and language understanding. Achievement pressure, director and excessive expectation were found to have effects on children's cognitive development.

• Journal of Ocean Engineering and Technology
• /
• v.13 no.4 s.35
• /
• pp.10-18
• /
• 1999

본 논문에서는 대형구조물의 해석에 있어서 부분구조합성법과 섭동법을 이용하여 복잡한 비선형시스템의 해석방법을 제안하였다. 해석방법은 전체시스템을 먼저 몇 개의 분계로 분할한다. 각 분계의 운동방정식에 비선형항이 존재하여도 전체시스템의 지배적 진동모드는 선형모드라는 가정하에 이 시스템의 각 분계를 모드좌표로 변환한다. 이때, 비선형항은 근사적으로 변환한다. 그리고 섭동법을 이용하여 각 분계의 모드좌표방정식은 섭동좌수별로 정식화되어 순차적으로 구해진다. 비선형의 감도는 비선형계수로 정의되고, 그에 상응하는 강성에 의해 구해진다. 제안된 해석방법으로 비선형회전체, 비선형 베어링-페데스탈로 구성된 대형시계구조물의 진동을 해석하였다. 해석방법의 유효성을 평가하기 위해 응답의 정도와 계산소요시간을 유한요소법의 결과와 비교 분석하였다.

• Computational Structural Engineering
• /
• v.5 no.3
• /
• pp.127-137
• /
• 1992

A method for nonstationary response analysis of an offshore guyed tower subjected to earthquake loading is presented. The nonstationarity of the earthquake excitation is modeled by imposing a time varying envelope function onto a stationary random model. By taking the envelope function and the auto-correlation function of ground acceleration in terms of complex exponential functions of time, an analytical procedure is developed for computing time varying variances of the tower response. Example analysis indicates that the maximum responses estimated by considering nonstationary effect properly are significantly less than those obtained by the conventional frequency domain analysis method based upon the stationary assumption.

• Journal of the Korean Society of Earth Science Education
• /
• v.11 no.2
• /
• pp.125-144
• /
• 2018

The purpose of this study is to analyze the astronomical thinking level of elementary, middle, and high school students using ordered multiple choice items. For this purpose, we constructed a questionnaire comprising three items about spatial thinking and system thinking. This survey was conducted and applied to 1,066 students in the 5th grade, 8th grade, and 11th grade in 12 schools located in Gangwon Province. The collected student response data were analyzed by applying inferential statistics of classical test theory and Rasch model. The results of the analysis were as follows; First, in the level of spatial thinking, students were able to grasp the spatial location and orientation of the celestial body, but were not able to convert the celestial motion of two-dimensional plane into three-dimensional plane, and it was revealed that there is no statistically significant difference in the spatial thinking of students among grade levels. Second, in the level of system thinking, students were able to identify the components and relationship between components of the celestial motion system, but could not identify the patterns of the system, and it was revealed that there was statistically significant difference among the system thinking of students in different grade levels, unlike in spatial thinking. Third, the astronomical thinking expressed in certain context (content) was very similar regardless of grade level, Through this, we could confirm the context-dependency or content-dependency of the astronomical thinking of students. It is expected that the results of this study can be used as basic data for exploring ways to enhance astronomical thinking level in school science classes.

• Journal of agricultural medicine and community health
• /
• v.40 no.1
• /
• pp.21-31
• /
• 2015

Objective: This study was to evaluate the health-related quality of life (HRQoL) among patients with diabetes in Korea and to compare them with the HRQoL of individuals without diabetes history. Methods: The study subjects were 17,655 adults aged over 19 who participated in the 5th Korea National Health and Nutrition Examination Survey (2010-2012). The EuroQoL-5Dimension was used to evaluate HRQoL. Chi-square test, t-test, ANOVA and multiple regression analysis were performed to test the difference of HRQoL in diabetic subjects and controls. Results: The mobility dimension was the highest reported problem: 36.4% for diabetic subjects. The proportion of any reported problem was significantly high among diabetic subjects compared with two controls in terms of mobility [reference group: diabetic subjects, chronic controls: adjusted odds ratio (aOR)=0.77, 95% confidence interval (95% CI)=0.66-0.91, healthy controls: aOR=0.61, 95% CI=0.50-0.75], self-care [reference group: diabetic subjects, chronic controls: aOR=0.68, 95% CI=0.55-0.83, healthy controls: OR=0.69, 95% CI=0.51-0.94]. and usual activities [reference group: diabetic subjects, chronic controls: aOR=0.85, 95% CI=0.72-0.99, healthy controls: OR=0.79, 95% CI=0.62-0.98]. Also, EQ-5D index were significantly low in subjects with diabetes compared to two controls. Conclusions: Subjects with diabetes had a significantly lower HRQoL compared with two controls. To improve the quality of life of diabetics, it is necessary to study various variables related to the quality of life, and develop and manage various health programs or welfare policies reflecting socio-demographic characteristics and health related features that affect the quality of life.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.41 no.5
• /
• pp.513-522
• /
• 2021

A smartphone (SMP) includes a MEMS sensor that can record 3-components motions and has a wireless network device to transmit data in live. These features and relatively low maintenance costs are the advantage of using SMPs as an auxiliary seismic observation network. Currently, 279 SMPs are monitoring seismic motions. In this study, we compare the SMP records with the seismic station (SS) records to validate SMP records. The data used for comparison are records for five earthquakes that occurred in 2019, which are 321 SS data recorded by the Korea Meteorological Administration and the Korea Institute of Geoscience and Mineral Resources and 145 recorded by SMPs. The analysis shows that the event-term corrected average residual of the SMP MEMS sensor records is 0.59 which indicating that the peak horizontal acceleration by SMP is 1.8 factor bigger than the peak ground acceleration by SS. In addition, the residuals tend to decrease as the installation floor of the smartphone MEMS sensor increases, which is the similar trend with response spectra from SS.

• Journal of Navigation and Port Research
• /
• v.42 no.6
• /
• pp.427-436
• /
• 2018

In this study, experimental and numerical analysis were performed on the survivability of a long pipe-type buoy structure in waves. The buoy structure is an articulated tower consisting of an upper structure, buoyancy module, and gravity anchor with long pipes forming the base frame. A series of experiment were performed in the ocean engineering basin of KRISO with the scaled model of 1/ 22 to evaluate the survivability of the buoy structure at West Sea in South Korea. Survival condition was considered as the wave of 50 year return period. Additional experiments were performed to investigate the effects of current and wave period. The factors considered for the evaluation of the buoy's survival were the pitch angle of the structure, anchor reaction force, and the number of submergence of the upper structure. Numerical simulations were carried out with the OrcaFlex, the commercial program for the mooring analysis, with the aim of performing mutual validation with the experimental results. Based on the evaluation, the behavior characteristics of the buoy structure were first examined according to the tidal conditions. The changes were investigated for the pitch angle and anchor reaction force at HAT and LAT conditions, and the results directly compared with those obtained from numerical simulation. Secondly, the response characteristics of the buoy structure were studied depending on the wave period and the presence of current velocity. Third, the number of submergence through video analysis was compared with the simulation results in relation to the submergence of the upper structure. Finally, the simulation results for structural responses which were not directly measured in the experiment were presented, and the structural safety discussed in the survival waves. Through a series of survivability evaluation studies, the behavior characteristics of the buoy structure were examined in survival waves. The vulnerability and utility of the buoy structure were investigated through the sensitivity studies of waves, current, and tides.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.5 no.1
• /
• pp.123-132
• /
• 1985

The flexibility of base material gives considerable influences on seismic responses of a structure. The effects of relative stiffness between super-structure and base material on dynamic soil-structure interaction are evaluated by parametric studies. Two 5-story buildings are used for the study; one is shearwall structure with relatively higher fundamental frequency and the other is frame structure with relatively lower fundamental frequency. The structures are modeled as beam-sticks coupled with springs and dashpots representing the base material. Dynamic equilibrium equations of the soil-structure interaction system are sloved by mode superposition method using Rosset modal damping values. Soil-structure interaction effect is found to be major concern in seismic analysis of shearwall structure in most cases while it seldom becomes engineering problem in frame-type structure. It is also found that seismic responses at lower elevation of the super-structure are amplified though they decrease at higher elevation as soil-structure interaction effects of the system increase.

• Journal of Environmental Impact Assessment
• /
• v.24 no.3
• /
• pp.217-232
• /
• 2015

This study is to examine the section-based stream management with environmental characteristics and user monitoring. In Jeonjucheon, upstream section located near to Jeonju Hanok village has very good water quality and natural stream landscape. In case of mid/down streams, water quality is good and heavy concentration of facility leads to high use rates of these sections. The questionnaire consists of 5 parts: user characteristics, use behavior, citizen participation, importance rank, and Importance-Satisfaction(IS). 383 out of 454 responses with listwise deletion are used for demographic analysis and IS Analysis. In terms of citizen participation through 'ecological experience activity' and 'stream stewardship activity', 'occasional participation' shows the average of 78% in all three sections. For importance rank, the results arranged in order of priority show 'water quality' > 'green corridor' > 'trail' in up/down streams and 'water quality' > 'vegetation management' > 'trail' in midstream. Therefore, 'water quality' appears to be the most important variable among 13 variables. At last, the results of ISA indicate that all 10 variables need to be improved as satisfaction is lower than importance. In addition, 'plant management' variable falls into 'concentrate here' quadrant where importance is high and satisfaction is low.