• Steel and Composite Structures
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• 제36권5호
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• pp.507-519
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• 2020

Double skin composite walls are increasingly popular and have been applied to many safety-related facilities. They come from the concept of composite slabs. Conventional connectors such as shear studs and binding bars were used in previous studies to act as the internal mechanical connectors to lock the external steel faceplates to the concrete core. However, the restraint effects of these connectors were sometimes not strong enough. In this research, a recently proposed unique type of steel truss was employed along the wall height to enhance the composite action between the two materials. Concrete-filled tube columns were used as the boundary elements. Due to the existence of boundary columns, the restraints of steel faceplates to the concrete differ significantly for the walls with different widths. Therefore, there is a need to explore the effect of height-to-width ratio on the structural behavior of the wall. In the test program, three specimens were designed with the height of 3000 mm, the thickness of 150 mm, and different widths, to simulate the real walls in practice. Axial compression was applied by two actuators on the tested walls. The axial behavior of the walls was evaluated based on the analysis of test results. The influences of height-to-width ratio on structural performance were evaluated. Finally, discussion was made on code-based design.

• 대한지역사회영양학회지
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• 제29권4호
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• pp.348-357
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• 2024

Objectives: The total population of Korea began to decline in 2019; in particular, the population in rural areas has been rapidly decreasing and is aging. Therefore, the government has designated depopulation areas and is seeking ways to support them. To assess whether health disparities exist between areas with population decline and those without, this study used community health survey data to observe temporal changes in health behaviors between the two types of areas. Methods: The analysis used Community Health Survey data from 2010 to 2019, and regional classification was divided by depopulation areas designated by the Ministry of the Interior and Safety. Trends in health behavior and chronic disease prevalence between depopulation and non-depopulation areas were analyzed. All analyses were conducted using complex sample analysis procedures in SAS 9.4 software. Results: The smoking rate steadily decreased in both depopulation and non-depopulation areas, whereas the high-risk drinking rate increased slightly. The walking practice rate did not improve in depopulation areas compared to non-depopulation areas. Furthermore, nutritional labeling usage rate was consistently lower in depopulation areas than in non-depopulation areas, with the gap being the largest. The prevalence of obesity, diabetes, and hypertension showed that the gap between depopulation and non-depopulation areas is continuously increasing. Conclusions: Health behaviors in depopulation areas have not improved, and the prevalence of chronic diseases is increasing rapidly. Therefore, the demand for health care services that support healthy lifestyle practices and chronic disease management in these areas is expected to increase.

• 한국ITS학회 논문지
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• 제20권3호
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• pp.47-58
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• 2021

최근 국내 PM 시장의 성장과 다수의 전동킥보드 공유 서비스 등장으로 이용자 수가 급증하면서 PM 관련 민원 및 안전사고 발생이 증가하고 있는 추세이다. 이에 따라, PM 조작 및 운행 미숙으로 인한 사고 감소 방안으로 PM 교육·연습 공간의 필요성이 대두되고 있다. 본 연구에서는 PM의 체계적 운영 및 활성화 방안을 마련하기 위해 관련 갈등 요소를 분석하고 그 대안으로 PM 플레이그라운드 운영 및 PM 시범구역 운영 방법을 검토하여 제안하였다. PM 플레이 그라운드 운영을 통한 기초데이터 수집 및 초보운전자 행태 분석으로 이용자의 운행 안전성 개선이 가능하며, 안전성 확보를 위한 시설 설치 방안을 통해 이용자와 비이용자 간 다양한 이해관계의 갈등 해소가 가능할 것으로 기대된다.

• 한국터널지하공간학회 논문집
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• 제23권6호
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• pp.403-421
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• 2021

제1기~제3기 지하철로 대표되는 우리나라 도심지 터널에는 대부분 관용터널공법에 의한 배수형 터널형식이 적용되어 있으나, 최근 도심지 대심도 공간을 적극적으로 활용하는 건설사업이 광범위하게 추진되고 있다는 점을 고려할 때, 기존 도심지 터널의 경험적 규칙에 부합하지 않는 부정적 영향이 발생할 수 있는데, 특히 주로 배수형식을 적용해 온 우리나라 터널기술 관행 상, 지하수 변동과 그에 따른 수리역학적 거동이 발생할 가능성이 크다. 배수형 터널형식 적용의 문제를 해결하기 위해 지하수 변동을 제어하는 시도가 이루어지고 있는 바, 그러한 경우에 필요한 터널 지하수 관리기준의 개념 설정 및 터널수리역학적 거동에 대한 분석을 수행하였다. 도심지 대심도 터널 건설로 인한 지하수 변동 문제를 예방하기 위해서는 현재, 수위를 획일적으로 제어하는 내용의 지하수 관리기준이 지하안전영향평가 단계에서만 적용되고 있는 경험적 기술관행과 관련하여, 터널 내 유입량을 제어하는 방향으로 개념전환이 필요하다는 점을 제시하고, 터널 계획시 허용유입량 설정에 필요한 지하수위 - 터널 내 유입량 관계를 도출하였다. 이러한 터널 지하수 관리개념의 도입이 향후 추진될 다양한 도심지 대심도 터널 건설사업에서 지하수 변동과 그로 인한 지반침하, 지하수자원 고갈 및 유지관리 성능저하 등의 문제 해결에 도움이 될 것으로 판단된다.

• Parasites, Hosts and Diseases
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• 제57권5호
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• pp.499-504
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• 2019

Head-lice infestation, pediculosis capitis, remains a public-health burden in many countries. The widely used first-line pediculicides and alternative treatments are often too costly for use in poor socio-economic settings. Ivermectin has been considered an alternate treatment for field practice. This study was composed of 2 parts, a cross-sectional survey and an intervention study. The main objectives were to determine the prevalence and potential factors associated with head-lice infestation, and to evaluate the effectiveness and safety of oral ivermectin administration. A community-based cross-sectional survey was conducted among 890 villagers in rural areas along Thai-Myanmar border. Females with infestations were eligible for the intervention study, and 181 participated in the intervention study. A post-treatment survey was conducted to assess acceptance of ivermectin as a treatment choice. Data analysis used descriptive statistics and a generalized-estimation-equation model adjusted for cluster effect. The study revealed the prevalence of head-lice infestation was 50% among females and only 3% among males. Age stratification showed a high prevalence among females aged <20 years, and among 50% of female school-children. The prevalence was persistent among those with a history of infestation. The major risk factors were residing in a setting with other infected cases, and sharing a hair comb. The study also confirmed that ivermectin was safe and effective for field-based practice. It was considered a preferable treatment option. In conclusion, behavior-change communication should be implemented to reduce the observed high prevalence of head-lice infestation. Ivermectin may be an alternative choice for head-lice treatment, especially in remote areas.

• 한국학교ㆍ지역보건교육학회지
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• 제24권4호
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• pp.13-26
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• 2023

Objectives: The purpose of this study was to explore the factors that influence aerobic physical activity among Korean adults, including sociodemographic characteristics, health behavior, health status, social relationships, community satisfaction, and to find ways to increase aerobic physical activity among adults. Methods: In 2019, 191,152 adults in the Community Health Survey were analyzed, and complex sample frequency analysis, Rao-Scott test and complex sample logistic regression analysis were conducted by dividing them into the presence or absence of aerobic physical activity practice. Results: The rate of aerobic physical activity among adults was 36.0%, and males were higher than females. Among individual factors, gender, age, income level, smoking, drinking, weight control attempt, frequency of breakfast, obesity, quality of life, and subjective health status were factors that had a significant effect. Among social relationship factors, leisure activities and contact with neighbors at least once a week were significant factors, and only overall safety level satisfaction was a factor that had a significant effect on physical activity practice in community satisfaction factors. Conclusion: Programs focused on personal factors, social relationships, and networks should be strategically developed to improve the participation rate of adult aerobic physical activities, indicating the importance of these factors over community infrastructure. To development of community-centered professional integrated health education will be necessary in the future.

• Structural Engineering and Mechanics
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• 제48권5호
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• pp.643-660
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• 2013

Reinforced concrete structures are vulnerable to high temperature conditions such as those during a fire. At elevated temperatures, the mechanical properties of concrete and reinforcing steel as well as the bond between steel rebar and concrete may significantly deteriorate. The changes in the bonding behavior may influence the flexibility or the moment capacity of the reinforced concrete structures. The bond strength degradation is required for structural design of fire safety and structural repair after fire. However, the investigation of bonding between rebar and concrete at elevated temperatures is quite difficult in practice. In this study, bond constitutive relationships are developed for normal and high-strength concrete (NSC and HSC) subjected to fire, with the intention of providing efficient modeling and to specify the fire-performance criteria for concrete structures exposed to fire. They are developed for the following purposes at high temperatures: normal and high compressive strength with different type of aggregates, bond strength with different types of embedment length and cooling regimes, bond strength versus to compressive strength with different types of embedment length, and bond stress-slip curve. The proposed relationships at elevated temperature are compared with experimental results.

• 지역사회간호학회지
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• 제18권1호
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• pp.90-101
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• 2007

Purpose: The purpose of this study was to investigate influencing factors of health problems which the vinyl house farmers had experienced. Method: Based on PRECEDE model, this study was done with 110 respondents(50 to 69 years old), working in vinyl house and living in the remote area where the primary health post located. Results: Quality of life was low in economical status, emotional status, and physical function. Health problems were founded as pain and chronic fatigue that were caused by physical symptoms, weakened physical strength, and increased blood pressure and cholesterol. Behavioral and environmental factors were related with lack of exercise, irregular eating habit, curtailed sleep, overwork, wrong working postures, stress, and non-fulfillment of safety standard during spraying pesticide. Self efficacy was low in excercise practice, working way, and stress management. Conclusion: The Health Promotion Program for vinyl house farmers should be developed to improve health promoting behavior and self efficacy, to reduce stress, and to strengthen physical function.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.186-192
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• 1999

Safety-related equipments of nuclear power plant must be seismically qualified to demonstrate their ability to function as required during and/or after the earthquake, The seismic qualification is usually achieved through analysis and testing. Analysis method is preferably adopted for structurally simple equipments which are easy to be mathematically modeled. However even for relatively complex equipments analysis method is occasionally used for computing the input motion or supporting information for the component test followed. Electrical cabinet is a typical example for which analysis method is combinedly used with test to get modal properties of the enclosing cabinet structure. Usually the structural elements and doors of the cabinet are loosely interconnected with small-size bolts or spot welding. Therefore cabinet-type equipment usually has high and complex nonlinear properties which are not easily idealized by simple practical modeling techniques. in this paper with respect to a typical cabinet-type structure(instrumentation cabinet of nuclear power plant) a comparative study has been performed between three different state-of-the -art modeling techniques: lumped mass model frame model and FEM modal. Form the study results it has been found that modal properties of the cabinet-type structure in the elastic behavior range can be reasonably computed through any type of modeling techniques in the practice with slight modification of model properties to get better accuracy. However it needs additional modeling techniques to get reasonable results up to nonlinear range.

• 대한치과마취과학회지
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• 제13권3호
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• pp.103-110
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• 2013

Background: Recently the use of sedation by pediatric dentists in Korea is increased. This study describes training programs about sedation practices in Korean pediatric dentistry residency program. Methods: A questionnaire was filled in by participants of Korean Academy of Pediatric Dentistry on 17th-18th August, 2008. Also the data about sedation practices of the training institution is collected by phone call. Results: Seventy two percent of respondents used sedation. Most of them used sedation with agents under 25% of their patients. Distribution of ages in patients sedated with agents was 3 years, 4-5 years, under 2 years, 6-10 years, and more than 10 years. Determinative factors of using sedation were behavior management, number of visiting, amount of treatment and general condition, and oral route was the most favorable route. Sixty six percent of them have failed on sedation, and thity percent of them have rarely failed on sedation. Only fifty percent of dentists using sedation completed the cardiopulmonary resuscitation course. Conclusions: For safety, dentists using sedation need to be educated about emergency equipment and management. Especially medication dose, use frequency and the detail related to treatment procedure should be discussed carefully. Also putting a patient under general anesthesia and taking emergency measures should be discussed with Korean Dental Society of Anesthesiology.