• 한국방재안전학회논문집
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• 제16권1호
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• pp.81-89
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• 2023

최근 이상기후의 영향으로 전 지구적 온난화 및 도시화로 인해 세계적으로 기상이변이 늘어나고 있다. 도시화 및 난개발로 인한 불투수 면적의 증가 같은 문제로 홍수량이 증가함에 따라 홍수피해를 줄이기 위한 다양한 방안이 제시되고 있다. 본 연구에서는 사행하천 구간에 설치되는 횡월류 위어 유입각의 변화에 따라 3차원 CFD 모형인 FLOW-3D를 이용하여 흐름 특성과 월류량을 분석하여 횡월류 위어 유입각에 대한 수공구조물의 월류능력 평가 및 유량계수 산정을 위한 기초 연구를 수행하였다. 분석 결과, 횡월류 위어 유입각이 작을수록 횡월류부 통과 후 주수로 흐름의 수위가 감소하고 유속이 증가하였으며, 유입각이 증가할수록 수위가 상승하였고, 유속이 감소하는 경향을 보였다. 또한, 횡월류 위어 유입각이 40° 이상인 경우 직하류 유속이 상류 유속과 비교하여 감소하는 것을 확인할 수 있었다.

• 한국간호교육학회지
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• 제29권3호
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• pp.225-233
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• 2023

Purpose: The aim of this study was to identify factors related to the vaccination intentions of nursing students before clinical practice. Methods: A descriptive correlational study design was used. The participants were 129 nursing students who were enrolled in one college of nursing in Seoul and were scheduled for clinical training. Data collection was conducted from February 28 to March 7, 2022. The data were analyzed using descriptive statistics, a t-test, ANOVA, Pearson's correlation coefficient, and a latitudinal regression analysis using the IBM SPSS statistics version 26.0 program. Results: The intention to vaccinate showed a significant correlation with vaccination attitude (r=.72, p<.001), subjective norms (r=.68, p<.001), and perceived behavioral control (r=.63, p<.001). The influencing factors on three intent to vaccinate were vaccination attitude (β=.36 p<.001), subjective norms (β=.31, p<.001), and perceived behavioral control (β=.36, p<.001). The explanatory power of these variables was 69.6%. Conclusion: The vaccination rate before the clinical training of nursing students was related to economic burden, a lack of time, and transportation problems that nursing college students experienced during the vaccination process. Therefore, administrative and financial support is needed for improving the vaccination rates of nursing students.

• 한국건축시공학회지
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• 제23권3호
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• pp.285-293
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• 2023

변경된 콘크리트 구조 내구성 설계기준과 콘크리트공사표준시방서에 규정된 탄산화에 대한 내구성평가와 관련된 사례를 조사하여 분석하고 실무적인 문제점을 분석한 결과 갑작스런 기준의 강화에 따른 경제적 부담이 높아졌음에도 인허가심의 과정에서의 우려로 외벽만 규정된 압축강도를 적용하고 나머지 구간에는 기존의 강도를 적용함으로써 시공성이 아주 불량해지고, 품질관리상 큰 부담이 있으며, 내구성평가기준이 모호한 한계를 극복할 수 있도록 사례를 제공하여야 할 것이며, 내구성을 확보대상을 명확히 하며, 공동주택에서 관행적인 층간 균열의 발생을 원천적으로 차단할 대책과 함께 유지관리단계의 균열관리 또한 규정에 반영하는 등 지난 2년간의 적용상 문제점을 종합적으로 분석하여 개정보완이 필요하다.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4134-4145
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• 2022

The collimator is one of the high-heat-flux components used to avoid a series of vacuum and thermal problems. In this paper, the heat load distribution throughout the collimator is first calculated through experimental data, and a transient thermodynamic simulation analysis of the original model is carried out. The error of the pipe outlet temperature between the simulated and experimental values is 1.632%, indicating that the simulation result is reliable. Second, the model is optimized to improve the heat transfer performance of the collimator, including the contact mode between the pipe and the flange, the pipe material and the addition of a twisted tape in the pipe. It is concluded that the convective heat transfer coefficient of the optimized model is increased by 15.381% and the maximum wall temperature is reduced by 16.415%; thus, the heat transfer capacity of the optimized model is effectively improved. Third, to adapt the long-pulse steady-state operation of the experimental advanced superconducting Tokamak (EAST) in the future, steady-state simulations of the original and optimized collimators are carried out. The results show that the maximum temperature of the optimized model is reduced by 37.864% compared with that of the original model. The optimized model was changed as little as possible to obtain a better heat exchange structure on the premise of ensuring the consumption of the same mass flow rate of water so that the collimator can adapt to operational environments with higher heat fluxes and long pulses in the future. These research methods also provide a reference for the future design of components under high-energy and long-pulse operational conditions.

• 한국재료학회지
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• 제32권3호
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• pp.132-138
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• 2022

Zintl phase Mg₃Sb₂ is a promising thermoelectric material in medium to high temperature range due to its low band gap energy and characteristic electron-crystal phonon-glass behavior. P-type Mg₃Sb₂ has conventionally exhibited lower thermoelectric properties compared to its n-type counterparts, which have poor electrical conductivity. To address these problems, a small amount of Sn doping was considered in this alloy system. P-type Mg₃Sb₂ was synthesized by controlled melting, pulverizing, and subsequent vacuum hot pressing (VHP) method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to investigate phases and microstructure development during the process. Single phase Mg₃Sb₂ was successfully formed when 16 at.% of Mg was excessively added to the system. Nominal compositions of Mg_3.8Sb_2-xSn_x (0 ≤ x ≤ 0.008) were considered in this study. Thermoelectric properties were evaluated in terms of Seebeck coefficient, electrical conductivity, and thermal conductivity. A peak ZT value ≈ 0.32 was found for the specimen Mg_3.8Sb_1.994Sn_0.006 at 873 K, showing an improved ZT value compared to intrinsic one. Transport properties were also evaluated and discussed.

• Journal of Preventive Medicine and Public Health
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• 제55권3호
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• pp.234-242
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• 2022

Objectives: This study assessed the validity and reliability of the Health-related Quality of Life Instrument with 8 Items (HINT-8) in patients with diabetes. HINT-8 is a newly-developed, generic health-related quality of life (HRQoL) instrument. Methods: Three HRQoL instruments-HINT-8, EuroQoL 5-Dimension 5-Level (EQ-5D-5L), and Short Form Health Survey version 2.0 (SF-36v2)-were provided to 300 patients with diabetes visiting a tertiary hospital for follow-up visits in Korea. The HRQoL scores obtained using the HINT-8 were evaluated for subgroups with known differences based on demographics and diabetes-related characteristics (known-group validity). The mean scores of the instruments were compared between groups segmented by their responses to the HINT-8 (discriminatory ability). Correlation coefficients of the HINT-8 with other instruments were calculated (convergent and divergent validity). The Cohen kappa and intra-class correlation coefficient (ICC) were also evaluated (test-retest reliability). Results: The average HINT-8 indexes were lower among women, older, and less-educated subjects. Subjects who did not list any problems on the HINT-8 had significantly higher HRQoL scores than those who did. The correlation coefficients of the HINT-8 with the EQ-5D-5L index and EuroQoL visual analogue scale were 0.715 (p<0.001) and 0.517 (p<0.001), respectively. The correlation coefficients between the HINT-8 index and the scores of 8 domains of the SF-36v2 ranged from 0.478 (p<0.001) to 0.669 (p<0.001). The Cohen kappa values for the HINT-8 ranged from 0.268 to 0.601, and the ICC of the HINT-8 index was 0.800 (95% confidence interval [CI], 0.720 to 0.860). Conclusions: This study showed that the HINT-8 is a valid and reliable HRQoL instrument for patients with diabetes.

• 문화기술의 융합
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• 제9권2호
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• pp.151-157
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• 2023

본 연구는 요양보호사를 대상으로 소명의식이 직무소진에 미치는 영향을 조사한 연구로, 총 230부를 배포하여 응답이 부실하거나 누락된 문항이 많은 설문지를 제외한 32부를 제외하고 총 198부를 분석에 사용하였다. 연구결과를 살펴보면 직무소진에 미치는 요인들 간의 상관관계는 개인환경의미, 일의의미 값들이 정적인 상관계수의 값을 가지는 것을 확인할 수 있었으며, 소명의식 하위요인이 직무소진에 미치는 영향을 살펴본 결과 개인환경적합이 유의미한 영향을 미치고 있는 것으로 나타났다. 종합적으로 요양보호사의 직무소진을 낮추기 위해서는 기관에 대한 직장생활을 할 수 있는 환경을 마련해주어야 한다. 또한 직장 내에 발생하는 문제에 대비하여 관련된 종합적인 기관 활성화가 필요할 것이다.

• 대한토목학회논문집
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• 제26권5B호
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• pp.481-488
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• 2006

본 연구는 준분포형 장기유출모형인 SWAT과 3차원 분포형 지하수 모형인 MODFLOW를 통합한 새로운 시도에 관한 것이다. SWAT모형은 준분포형 특성상 지하수 성분중에서 투수계수나 저류계수등의 분포형 매개변수를 고려할 수 없으며 지하수 함양량, 수두와 양수량 분포 등을 고려하는데에도 어려움이 있다. 이와같은 문제점을 극복하기 위해 SWAT의 수문반응단위인 HRU와 MODFLOW의 기본단위인 셀간의 특성치들을 주고받을 수 있는 완전연동형 기법을 제시하였다. 이러한 결합은 하천망과 대수층간의 상호작용을 경계흐름으로 고려함으로써 완성되었다. SWAT-MODFLOW 결합모형을 우리나라 경안천 수위관측소 유역에 시험적으로 적용한 결과, 포화대와 하천지류간의 상호작용이 경안천 유역의 유출량 산정에 중요한 역할을 한다는 것을 알 수 있었다. 이와 함께 결합모형은 지하수두 및 함양량의 시공간적 변동성을 재현하는 등 광범위한 적용가능성을 보여주었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.75-75
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• 2022

Traditional agriculture mostly focused on activity in the field, but current agriculture faces problems such as reduction of agricultural inputs, labor shortage and so on. Accordingly, traditional agricultural experiments generally considered the simple treatment effects, but current agricultural experiments need to consider the several and complicate treatment effects. To analyze such several and complicate treatment effects, data collection has the first priority. Remote sensing is a quite effective tool to collect information in agriculture, and recent easier availability of UAVs (Unmanned Aerial Vehicles) enhances the effectiveness. LAI (Leaf Area Index) is one of the most important information for evaluating the condition of crop growth. In this study, we utilized UAV with multispectral camera to evaluate plant-based LAI of sweetcorn in a small-scale field experiment and discussed the feasibility of a new experimental design to analyze the several and complicate treatment effects. The plant-based SR measured by UAV showed the highest correlation coefficient with LAI measured by a canopy analyzer in 2018 and 2019. Application of linear mix model showed that plant-based SR data had higher detection power due to its huge number of data although SR was inferior to evaluate LAI than the canopy analyzer. The distribution of plant-based data also statistically revealed the border effect in treatment plots in the traditional experimental design. These results suggest that remote sensing with UAVs has the advantage even in a small-scale experimental plot and has a possibility to provide a new experimental design if combined with various analytical applications such as plant size, shape, and color.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.124-130
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• 2023

Recently, fan out wafer level packaging, which enables high integration, miniaturization, and low cost, is being rapidly applied in the semiconductor industry. In particular, FOWLP is attracting attention in the mobile and Internet of Things fields, and is recognized as a core technology that will lead to technological advancements such as 5G, self-driving cars, and artificial intelligence in the future. However, as chip density and package size within the package increase, FOWLP warpage is emerging as a major problem. These problems have a direct impact on the reliability and electrical performance of semiconductor products, and in particular, cause defects such as vacuum leakage in the manufacturing process or lack of focus in the photolithography process, so technical demands for solving them are increasing. In this paper, warpage simulation according to the thickness of FOWLP material was performed using finite element analysis. The thickness range was based on the history of similar packages, and as a factor causing warpage, the curing temperature of the materials undergoing the curing process was applied and the difference in deformation due to the difference in thermal expansion coefficient between materials was used. At this time, the stacking order was reflected to reproduce warpage behavior similar to reality. After performing finite element analysis, the influence of each variable on causing warpage was defined, and based on this, it was confirmed that warpage was controlled as intended through design modifications.