• 환경영향평가
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• 제23권3호
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• pp.208-219
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• 2014

This work aims to establish the landscape ecological countermeasures to improve the sustainability of urban mountain forest and to enrich the biodiversity in twenty mountains of the Seoul Metropolitan City. Landscape ecological analysis was conducted based upon various criteria, such as area and elevation of mountains, flora, naturalized plants, vegetation, forest types, mountain trails, and public facilities. Various measures were suggested for the better maintenances of floristic diversity, introduced plants, vegetation and forest types of urban mountain forests. Sustainable recommendations for land use adminstration were developed for the preparations of a climate change-adapted urban mountain forests, as well as rational managements of ecosystem, walking trails, and public facilities within mountain forest. Rich and diverse natural vegetation as well as high floristic diversity were reported at mountains with higher elevations, larger area size, and rich landscape diversity. Mountains with low elevation, small size with easy public access, however, might require an urgent action to decrease the burdens by anthropogenic disturbances and urban development.

• 농촌계획
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• 제19권1호
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• pp.43-54
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• 2013

School closings in rural area continue to occur due to drops in population in those areas. Many studies have been done in order to effectively utilize such closed schools. However, there is a lack of studies targeting operators of the closed facilities for revitalization. Therefore, the goal of this research is understanding the real operational status of and finding solutions for the closed schools after studying the current operational status of the closed schools by conducting surveys with their operators. The survey was performed with closed-school-operators in Chungcheongnam-Do as the target; and the analysis was conducted regarding the acquisition type of the closed schools (purchase, lease), building condition, repair and construction status, annual visitors, operational days, operational fees, seasonal ups and downs, operational profits, and satisfaction of local government support. The results showed that there were differences with visitors and operational days along acquisition types as well as low operational profits and seasonal ups and downs including dissatisfaction of local government support. In this study, institutional and political improvement measurements were suggested for the effective operation of the closed facilities based on the main results.

• 교육시설 논문지
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• 제26권2호
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• pp.3-10
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• 2019

This study evaluated the vibration use and safety of students living in the dormitories on the 12th and 14th floors by feeling uncomfortable. The measurement method was to measure the acceleration due to free vibration and single - person walking. The slab stiffness was then calculated, and the usability and safety were compared according to international standards. The natural frequency of the slab was 6.8 Hz. The natural frequency of a typical slab is around 15Hz. Therefore, the evaluation slab is judged as a flexible floor structure. It is considered that there is a high possibility of resonance in the middle of daily life because of low natural frequency and near harmonic component of walking vibration. As a result, the RMS acceleration level is within the tolerance range defined by ISO 10137 code, but the 13th floor exceeds the reference limit, so that a sensitive person could detect the vibration somewhat in the lying position.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.825-836
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• 2019

One of the most challenging safety precautions for workers in dynamic, radioactive environments is avoiding radiation sources and sustaining low exposure. This paper presents a sampling-based algorithm, DL-RRT*, for minimum dose walk-path re-planning in radioactive environments, expedient for occupational workers in nuclear facilities to avoid unnecessary radiation exposure. The method combines the principle of random tree star ($RRT^*$) and $D^*$ Lite, and uses the expansion strength of grid search strategy from $D^*$ Lite to quickly find a high-quality initial path to accelerate convergence rate in $RRT^*$. The algorithm inherits probabilistic completeness and asymptotic optimality from $RRT^*$ to refine the existing paths continually by sampling the search-graph obtained from the grid search process. It can not only be applied to continuous cost spaces, but also make full use of the last planning information to avoid global re-planning, so as to improve the efficiency of path planning in frequently changing environments. The effectiveness and superiority of the proposed method was verified by simulating radiation field under varying obstacles and radioactive environments, and the results were compared with $RRT^*$ algorithm output.

• 한국안전학회지
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• 제36권2호
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• pp.18-25
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• 2021

Specialty contractor facilities, which involve a combination of welding and commissioning, face a high risk of serious accidents such as fire, explosion, and suffocation associated with welding work, nitrogen, and argon use. In such facilities, the organizational safety culture has considerable impact on the frequency of accidents. In this study, a safety culture evaluation was conducted on specialty contractors. NOSACQ-50, a standardized survey method on safety culture, was selected as an assessment tool to evaluate the safety culture in specialized construction companies that could not afford to invest heavily in safety. The self-administered questionnaire survey was conducted with 201 workers of four construction companies and the results were analyzed. It was found that in companies with low safety culture, the occurrence of irrationality was 66.0%, while in companies with high safety culture, the occurrence of irrationality was 42.6%. Thus, the difference in the occurrence of irrationality by safety culture was statistically significant. The difference in safety culture level according to the experience of occurrence of irrationality was also significant. It was also found that the higher the belief in safety management authorization, safety responsibilities of managers, worker safety priorities, and safety system effects, the lower the probability of irrationality.

• Perspectives in Nursing Science
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• 제6권1호
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• pp.55-65
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• 2009

The Korean government introduced Home Care Services System to cut medical cost and make efficient use of limited medical resources because of increasing chronic diseases and the growing population of the elderly. The Korean government established measures to control the use of insurance services by restricting the number of nurse's visits to patient's home and by asking the patients to shoulder the transportation fee of nurses during the visit. Factors such as oversupply of hospital facilities, low price of home care services, high insurance coverage for hospital services and increased nuclear family set up resulted in the limited use of home care nursing services. The introduction of long-term care insurance in 2007 brought the decrease in the number of home care agencies and these agencies are facing a crisis today. The increase in chronic diseases and growing population of the elderly recently resulted in the need to control the high medical cost. Home care services for early discharge patients and chronic-severe disease patients will contribute in the reduction of medical cost at the same time improves the quality of patient's life. To catch up with the demands of the nation, accessibility to home care services should be improved and policies such as the expansion of home care services insurance coverage and promotion of establishing home care agencies should be considered.

• 한국가스학회지
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• 제9권3호
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• pp.32-37
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• 2005

LP가스나 도시가스시설의 저압 호스 체결에서 견고함과 기밀성을 높이기 위해 호스밴드를 사용한다. 본 연구에서는 호스밴드의 성능 파악과 안전한 체결 거리의 제시를 위하여 호스밴드에 대한 내압강도와 당김력을 측정하였다. 호스밴드의 체결력은 스프링밴드 보다는 귀형밴드에서 높게 나타났으며 최적의 호스밴드 체결거리는 호스접속 끝단부로부터 1${\~}$2 mm일 때에 우수한 것으로 파악되었다.

• 대한전자공학회논문지TE
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• 제37권1호
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• pp.89-98
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• 2000

본 논문은 포워드 컨버터에 사용한 플레너 자기 소자의 설계 방법과 동작 특성에 관해 연구하였다. 플레너 자기 소자는 고주파 SMPS 설계시 발생할 수 있는 문제점에 대한 좋은 해결책이 될 수 있다. 이러한 플레너 자기 소자는 낮은 누설 리액터스, 낮은 구조, 경량 및 EMI 영향을 최소화 할 수 있는 등 여러 가지 좋은 장점들을 가지고 있어 최근 그 사용이 증대되고 있다. 본 논문에서는 플레너 자기소자를 이용한 포워드 컨버터를 제작한 후, 실험을 통하여 기존의 변압기를 사용한 경우와 비교하여 그 성능의 우수성을 입증하였다.

• Corrosion Science and Technology
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• 제22권5호
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• pp.351-358
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• 2023

Although many thermal power plants use heat recovery systems, high exhaust gas temperatures are maintained due to corrosion at dew points and ash deposits caused by condensate formation. The dew point of exhaust gas is primarily determined by the concentration of SO₃ and steam, and various experiments and calculation equations have been employed to estimate it. However, these methods are known to be less suitable for exhaust gases with low SO₃ concentrations. Therefore, in this study, since the temperature of the exhaust gas is expected to decrease due to the low-load operation of the coal-fired power plant, sulfuric acid condensation and low-temperature corrosion are anticipated. We aimed to conduct a quantitative evaluation to propose ways to prevent damage by limiting operating conditions and improving facilities. The experimental results showed that the corrosion rate increased linearly with rising temperatures at a certain sulfuric acid concentration. Furthermore, variations in sulfuric acid concentrations generated during the current power plant operation process did not significantly affect the dew point, and the dew point of sulfuric acid under these conditions was observed to be between 120 - 130 ℃.

• Journal of Information Science Theory and Practice
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• 제4권4호
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• pp.49-63
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• 2016

The emergence of the World Wide Web (WWW) has changed the scholarly publishing system. Today, Open Access (OA) scholarly publishing offers free access and wide dissemination for research findings anytime and anywhere as an additional value for scholarly content. Despite the potentials of OA publishing, its adoption and use is still low.This paper determines factors influencing the adoption and use of OA publishing by academic staff in universities in Nigeria using an adapted Unified Theory of Acceptance and Use Technology (UTAUT). The study applies methodological triangulation by combining quantitative and qualitative approaches. The empirical data were collected from 317 academic staff in universities in southwest Nigeria. The questionnaire forms were analyzed using the Statistical Package for Social Sciences (IBM-SPSS) 19.0 version to generate descriptive statistics, Analysis of Variance, and Hierarchical Multiple Regression. Thematically, analysis also applies to the interviews. The results show that awareness, attitude, performance expectancy, Internet self-efficacy, and facilitating conditions significantly influenced the adoption and use of OA publishing. The study also reveals that due to lack of OA policy, most of the respondents did not know about OA. The findings further establish that all predictors and moderating variables jointly contributed 64.4% total variance towards the adoption and use of OA publishing. One of the implications of this study is that there is a need for adequate facilities to support adoption and use of OA publishing. The findings inform the proposed framework for improving and evaluating the adoption and use of OA publishing. The findings also have theoretical, societal, and methodological significance to all stakeholders.