• 한국측량학회지
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• 제39권1호
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• pp.29-40
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• 2021

범죄, 화재, 교통사고 등 국민의 안전을 위협하는 위험인자들은 지역적 맥락과 공간적 특성을 가지고 있다. 지역마다 서로 다른 위험환경을 가지고 있으므로 교통사고, 화재, 범죄, 생활안전 분야별로 위험요소의 공간적 패턴을 분석할 필요가 있다. 본 연구는 전국 기초자치단체를 대상으로 분야(교통사고, 화재, 범죄, 생활안전, 자살, 감염병)별 안전등급을 측정한 지표인 지역안전지수의 공간적 분포 패턴을 분석하는데 연구의 목적이 있다. 지역안전지수의 공간적 자기상관성 분석을 위해 전역적 공간자기상관분석(Global Moran's I)과 Local Moran's I를 활용한 LISA(Local Indicators of Spatial Association) 분석, Getis-Ord's G⁎i 분석을 실시하였다. 분석결과 교통사고, 화재, 자살의 안전지수 분포는 범죄, 생활안전, 감염병의 안전지수보다 공간적으로 집중(clustered) 경향을 보였다. 지역간 유의미한 공간적 연관성을 분석한 LISA 분석결과에 따르면, 수도권 지역이 다른 도시에 비하여 지역안전통합지수를 기준으로 비교적 안전한 지역인 것으로 나타났다. 또한 Getis-Ord's G⁎i 통계값을 활용한 핫스팟분석 결과 안전 취약지역의 군집인 3개의 핫스팟(강원도 삼척시, 경상북도 청송군, 전라북도 김제시)과 전반적인 안전 수준이 높은 군집인 15개의 콜드스팟이 도출되었다. 이러한 연구 결과는 안전 수준 취약지역의 공간적 분포와 패턴을 파악하여 안전 지수 개선을 위한 정책 수립시 기초자료로 활용될 수 있다.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3775-3786
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• 2023

Mixing Vane Grid (MVG) is one of the most important structures in fuel assembly due to its high performance in mixing the coolant and ultimately increasing Critical Heat Flux (CHF), which avoids the temperature rising suddenly of fuel rods. To evaluate the mixing performance of the MVG, a Total Diffusion Coefficient (TDC) mixing coefficient is defined in the subchannel analysis code. Conventionally, the TDC of the spacer grid is obtained from the combination of experiments and subchannel analysis. However, the processing of obtaining and determine a reasonable TDC is much challenging, it is affected by boundary conditions and MVG geometries. In is difficult to perform all the large and costing rod bundle tests. In this paper, the CFD method was applied in TDC analysis. A typical 5 × 5 MVG was simulated and validated to estimate the mixing performance of the MVG. The subchannel code was used to calculate the TDC. Firstly, the CFD method was validated from the aspect of pressure drop and lateral temperature distribution in the subchannels. Then the effect of boundary conditions including the inlet temperature, inlet velocities, heat flux ratio between hot and cold rods and the arrangement of hot and cold rods on MVG mixing and TDC were studied. The geometric effects on mixing are also carried out in this paper. The effect of vane pattern on mixing was investigated to determine which one is the best to represent the grid's mixing performance.

• Clinical and Experimental Pediatrics
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• 제64권12호
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• pp.632-641
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• 2021

Background: Over the past few decades, various goals have been defined to reduce the mortality of children caused by acute lower respiratory infections (ALRIs) worldwide. However, few spatial studies to date have reported on ALRI deaths. Purpose: We aimed to assess the spatial modeling of mortality from ALRI in children under 5 years of age during 2000-2017 using a global data. Methods: The data on the mortality of children under 5 years old caused by ALRI were initially obtained from the official website of the World Health Organization. The income status of their home countries was also gathered from the Country Income Groups (World Bank Classification) website and divided into 5 categories. After that, in the ArcGIS 10.6 environment, a database was created and the statistical tests and related maps were extracted. The Global Moran's I statistic, Getis-Ord Gi statistic, and geographically weighted regression were used for the analyses. In this study, higher z scores indicated the hot spots, while lower z scores indicated the cold spots. Results: In 2000-2017, child mortality showed a downward trend from 17.6 per 100,000 children to 8.1 and had a clustered pattern. Hot spots were concentrated in Asia in 2000 but shifted toward African countries by 2017. A cold spot that formed in Europe in 2007 showed an ascending trend by 2017. Based on the results of geographically weighted regression test, the regions identified as the hot spots of mortality from ALRI in children under 5 years old were among the middle-income countries (R²=0.01, adjusted R²=8.77). Conclusion: While the total number of child deaths in 2000-2017 has decreased, the number of hot spots has increased among countries. This study also concluded that, during the study period, Central and Western Africa countries became the main new hot spots of deaths from ALRI.

• 한국농촌생활과학회지
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• 제5권1호
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• pp.1-8
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• 1994

온랭 열 자극에 대하여 인체의 말초 혈류량과 심박수가 어떻게 반응하는가를 관찰하기 위하여 건강한 성인 여자 4명을 피험자로 실험군과 비교군으로 나누어 실험을 실시하였다. 실험군은 온랭열 자극의 단기 훈련을 12회 실시하고 비교군은 실험군의 초기와 말기 2회 실시하여 얻은 결과를 비교ㆍ검토하여 다음과 같은 결과를 얻었다. $\circled1$ 실험군에서의 손가락 혈류량의 초기 반응은 훈련 후에 민감해졌다. $\circled2$ 심박수는 냉수 노출시보다 온수 노출시 증가하였다. $\circled3$ 실험군과 비교군간에는 혈류량의 변화 형태와 심박수에 차이가 있었다. 이상에서 E-군과 C-군의 혈류량과 심박수에서 차이를 나타낸 것은 단기 훈련 효과에 의한 것으로 추정된다.

• 한국추진공학회지
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• 제3권3호
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• pp.1-8
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• 1999

$H_2$O/Kerosene을 사용하여 Unlike 충돌형 인젝터(FOOF형)에서 산화제와 연료의 운동량비 변화에 따른 혼합효율을 측정하였다. 모의 추진제의 운동량비 1.5(총혼합비 1.89)에서 혼합성능은 최대 값을 나타내었으며 모의 추진제의 실험결과는 실제 추진제인 LOX/Kerosene에 적용하여 혼합특성속도 효율을 예측하였다 연구 결과 혼합특성속도 효율은 운동량비 2.0에서 최대 값을 나타내었다. 이러한 예측은 실제 연소실험을 통하여 얻어진 연소효율과 약간의 차이는 있으나 초기설계자료로서 충분한 가치가 있는 것으로 판단된다.

• The Plant Pathology Journal
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• 제31권4호
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• pp.323-333
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• 2015

As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock proteins (HSPs) functioning as molecular chaperones are the key components responsible for protein folding, assembly, translocation, and degradation under stress conditions and in many normal cellular processes. Plants respond to pathogen invasion using two different innate immune responses mediated by pattern recognition receptors (PRRs) or resistance (R) proteins. HSPs play an indispensable role as molecular chaperones in the quality control of plasma membrane-resident PRRs and intracellular R proteins against potential invaders. Here, we specifically discuss the functional involvement of cytosolic and endoplasmic reticulum (ER) HSPs/chaperones in plant immunity to obtain an integrated understanding of the immune responses in plant cells.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2273-2278
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• 2007

Brazed Plate Heat Exchanger (BPHE) is a type of compact plate heat exchanger with parallel corrugated plates which are brazed together in series. Each plate hascorrugation called herringbone pattern. Inside a BPHE, hot fluid and cold fluid alternate its flow direction to establish counter current flow configuration. Two-phase flow heat transfer and pressure drop of R-22 in BPHE were experimentally measured in this study. In the present experiments, single-phase region and two-phase region coexist in a BPHE. Therefore, the inside of a BPHE have to be divided into single phase region and two phase region and analyzed accordingly. The results from the single phase flow analysis are then extended to the two phase flow analysis to correlate the condensation and evaporation heat transfer and pressure drop for the refrigerant R-22 in the BPHEs. Previous models for two- phase friction factor have been compared with the present experimental results.

• 대한산업공학회지
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• 제25권4호
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• pp.476-489
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• 1999

This paper is concerned with the deployment of core technologies for automotive steel sheets, based on the structural change of global market. The main tasks of automotive industry are to ensure the energy consumption, environmental regulations, and driving safety. With social and legal requirements, this study analyzes the market creation processes with technological innovations for hot rolled, cold rolled and galvanized steel sheets during the 20th century. It has been proven that the leading country in the steel industry was also that in the automotive. The purchaser-supplier relations of sheet materials are then patternized in the regional markets of the United States and Japan, who share nearly 50% of market in the world. According to the paradigm shift of globalization, the balance of power in Porter's 5 forces has been moved to the buyers', and both industries pursue Win-Win strategies such as the PNGV(Partnership for a New Generation of Vehicles ) and design-in system with the competition.

• Journal of Advanced Marine Engineering and Technology
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• 제23권4호
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• pp.559-564
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• 1999

A particle image velocimetry is the representative technique for measuring flow velocities at whole field simultaneously. The present study adopted the PTV method for velocity acquisition in a square enclosure with initially isothermal fluid by using a general lamp-based sheet light source. The enclosure was composed of hot and cold vertical wall and was confined by two horizon-tal adiabatic walls. The drift velocities were measured and the drift was visualized by PTV for a rayleigh number of 5.28{\times}10^8.$ Obtained instant simulataneous velocity vectors show flow pattern and the result of horizontal velocity profile agree well with the numerical result.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1675-1677
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• 2005

In case of attaching thermoelectric module and heat source, the polymer sheet is attached on the $AL_{2}O_3$ plate, which Is cold and hot side of thermoelectric module, in order to enhance mechanical safty of the system. It is impossible to calculate the exact distribution of temperature and flow pattern of inner gap of thermoelectric module. Therefore CFD(Computational Fluid Dynamics) analysis was executed to determine the thermo-fluid phenomena and distribution by Fluent. As the result of these analysis, heat transfer was dominated by conduction and the difference of temperature was linear distribution according to the thickness of polymer sheet.