• 지식경영연구
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• 제22권4호
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• pp.173-187
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• 2021

투입 증대를 통한 경제성장 전략은 급격히 변화하는 경제환경과 맞물리면서 한계를 보이면서 기업의 투입 대비 효율성에 대한 관심이 증가하고 있다. 본 연구는 국내 제조기업 중 연구개발 투자액 상위 938개 기업의 2005~2018년 패널 데이터를 활용하여 기업의 효율성을 측정하고, 효율성에 영향을 주는 요인을 분석하였다. 분석 결과, 기업의 혁신을 위한 투입인 연구개발집중도와 연구개발 성과인 특허가 모두 기업의 효율성을 높이는 것으로 나타났다. 이 밖에 기업의 규모, 부채비율, 수익성 등도 기업의 효율성에 유의미한 영향을 주었다. 분석결과를 통해 본 연구는 기업의 낮은 효율성을 극복하기 위한 지식경영 관점에서의 시사점을 제시하였다.

• 한국분무공학회지
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• 제27권3호
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• pp.134-143
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• 2022

When a recess is applied to a swirl coaxial injector that uses liquid and gas propellants, a self-pulsation phenomenon in which the spray oscillates at regular intervals may occur. The phenomenon is caused by the interaction between the liquid and gas propellants inside the injector recess region. The propellants' kinetic energies are expected to affect significantly the spray oscillation. Therefore, cold-flow tests using helium as a gas-simulating propellant were conducted and compared with the results of the previous study using air. Dynamic pressure was measured in the injector manifold and frequency characteristics were investigated through the fast Fourier transform analysis. In the experimental environment, the helium density was about seven times lower than the air density. Accordingly, the intensity of pressure fluctuations was confirmed to be greater when air was used. At the same kinetic energy condition, the perturbation frequency was almost identical in the low flow rate conditions. However, as the flow rate increased, the self-pulsation frequency was higher when helium was used.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.95-95
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• 2020

Urban flooding occurs in the form of internal-water inundation on roads and lowlands due to heavy rainfall. Unlike in the case of rivers, inundation in urban areas there is lacking in research on predicting and warning through measurement data. In order to analyze urban flood patterns and prevent damage, it is necessary to analyze flooding measurement data for various rainfalls. In this study, the pattern of urban flooding caused by rainfall was analyzed by utilizing the urban flooding measuring sensor, which is being test-run in the flood prone zone for urban flooding management. For analysis, 2019 rainfall data, surface water depth data, and water level data of a street inlet (storm water pipeline) were used. The analysis showed that the amount of rainfall that causes flooding in the target area was identified, and the timing of inundation varies depending on the rainfall pattern. The results of the analysis can be used as verification data for the urban inundation limit rainfall under development. In addition, by using rainfall intensity and rainfall patterns that affect the flooding, it can be used as data for establishing rainfall criteria of urban flooding and predicting that may occur in the future.

• 한국농촌간호학회지
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• 제18권1호
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• pp.40-48
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• 2023

Purpose: This study is a descriptive research that analyzes the current status of education for COVID-19 response tasks and factors affecting work fatigue of primary health care practitioners who have experience in dispatching to respond to COVID-19. Methods: This study collected data through an online survey from September 21 to 29, 2022, targeting 193 primary health care practitioners. The data were analyzed by frequency, percentage, mean, standard deviation, and logistic regression analysis using the SPSS 25.0 program. Results: 74.1% of the study subjects were dispatched without receiving disaster medical training to respond to COVID-19. 59.6% of the study subjects' work fatigue was above the level of being very tired. The factors that affect the work fatigue of the subjects were disaster participation experience, work intensity, compensation regulations, compensation satisfaction, and understanding of COVID-19 guidelines. Conclusion: Based on the results of this study, an educational program for systematic disaster response and preparation for primary health care practitioners in charge of public health care should be developed to efficiently cope with the occurrence of new infectious diseases in the future.

• Physical Therapy Rehabilitation Science
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• 제12권2호
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• pp.115-122
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• 2023

Objective: A previous study reported that cardiovascular training (CT) decreased interleukin-6 (IL-6), a pro-inflammatory cytokine with bidirectional effects. However, because of conflicting results of increasing and decreasing IL-6 levels in stroke patients, it is essential to clarify the effects of CT on IL-6 levels in this population. Therefore, this review aimed to investigate the effects of CT on IL-6 levels in stroke patients through a meta-analysis of randomized controlled trials (RCTs), synthesizing and analyzing the effects qualitatively and quantitatively. Design: A systematic review and meta-analysis of randomized controlled trials. Methods: In this review, conducted in April 2023, electronic databases (Web of Science, CINAHL, Embase, MEDLINE, Google Scholar) were searched to ascertain the effects of CT on IL-6 levels in stroke patients. For qualitative evaluation, ReVMan, provided by the Cochrane Group, was used, and for quantitative evaluation, a random-effects model and SMD (Standardized Mean Difference) were used. Results: Three RCTs measured IL-6 in 117 patients with stroke. The experimental group to which CT was applied showed no significant change compared to the control group.The result of analysis using the random effect model is SMD=-0.23; 95% confidence interval, -0.66 to 0.20. Conclusions: CT does not affect IL-6 levels in stroke patients. These results suggest that CT can be applied regardless of its positive or negative effect on IL-6 levels in stroke patients.

• Steel and Composite Structures
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• 제51권1호
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• pp.63-72
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• 2024

This study delves into the interaction dynamics between lateral notches and inclusions, providing valuable insights for more effective engineering of structural components. By employing the finite element method, the research analyzes how inclusions affect the dimensions and contours of the plastic zone under confined plasticity conditions. Several parameters were investigated, including loading influence, the distance between the inclusion and notch tip, inclusion stiffness, and the distribution of Von Mises stress, as well as normal stresses σxx and σyy, and Comparison between different stresses. Examining stress distributions under varying loading conditions reveals a significant intensification, particularly near the crack tip. Moreover, the presence of an inclusion near the notch base reduces both the size and shape of the plastic zone. The distribution of the stresses for different loads knows an increase in intensity, especially near the crack head, which is the most requested by the tensile forces on its upper part, which can cause either the crack's initiation or opening, inducing significant stresses.

• 한국지진공학회논문집
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• 제28권1호
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• pp.1-10
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• 2024

For important structures such as nuclear power plants, In-Structure Response Spectrum (ISRS) analysis is essential because it evaluates the safety of equipment and components installed in the structure. Because most structures are asymmetric, the response can be affected by eccentricity. In the case of seismically isolated structures, this effect can be greater due to the difference between the center of mass of the structure and the center of rigidity of the isolator layer. Therefore, eccentricity effects must be considered when designing or evaluating the ISRS of seismically isolated structures. This study investigated the change of the ISRS of an isolated structure by assuming accidental eccentricity. The variables that affect the ISRS of the isolated structure were analyzed to see what additional impact they had due to eccentricity. The ISRS of the seismically isolated structure with eccentricity was amplified more than when there was non-eccentricity, and it was boosted more significantly in specific period ranges depending on the isolator's initial stiffness and seismic intensity. Finally, whether the displacement requirement of isolators can be applied to the variation of the ISRS due to eccentricity in the design code was also examined.

• 농업과학연구
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• 제50권4호
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• pp.927-940
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• 2023

Online shopping has been undergoing significant developments in the South Asian region in the last decade. Using a representative sample of Sri Lankan consumers, this study explored online food purchasing behavior in Sri Lanka, a developing nation and island in South Asia. Data were collected from 562 respondents from all nine provinces in Sri Lanka using an online survey. Consumer attitudes were evaluated using factor analysis, and factor scores were added as explanatory variables to the final model. An ordered logistic regression model was used to examine the impact of consumer demographics, economic variables, and consumer attitudes on online food purchases. Online food purchasing intensity was categorized into four groups that suited ordinal rankings: zero for never, low for rarely, medium for occasionally, and high for regularly. Results indicated that age, income, education, and living in urban areas affect the online food purchasing behavior of Sri Lankan consumers. In addition, trust, convenience, and attitudes toward price were powerful drivers of online food purchasing. The findings have a number of significant managerial ramifications for creating strategies to promote online food purchases in developing South Asian nations like Sri Lanka. Moreover, promoting online shopping could be a potential solution for traffic congestion, ultimately helping to mitigate the negative externalities associated with it, such as carbon emissions and air pollution.

• 한국축산식품학회지
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• 제44권2호
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• pp.309-325
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• 2024

The consumption of meat has been increasing, leading to a dynamic meat and meat processing industry. To maintain the quality and safety of meat products, various technologies have been explored, including intense pulsed light (IPL) technology. Several factors affect the inactivation of microorganisms by IPL treatment, including light intensity (fluence), treatment duration, pulse frequency, and the distance between the lamp and the samples. Meat products have been studied for IPL treatment, resulting in microbial reductions of approximately 0.4-2.4 Log. There are also impacts on color, sensory attributes, and physico-chemical quality, depending on treatment conditions. Processed meat products like sausages and ham have shown microbial reductions of around 0.1-4 Log with IPL treatment. IPL treatment has minimal impact on color and lipid oxidation in these products. Egg products and dairy items can also benefit from IPL treatment, achieving microbial reductions of around 1-7.8 Log. The effect on product quality varies depending on the treatment conditions. IPL technology has shown promise in enhancing the safety and quality of various food products, including meat, processed meat, egg products, and dairy items. However, the research results on animal-based food are not diverse and fragmentary, this study discusses the future research direction and industrial application through a review of these researches.

• 대한지리학회지
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• 제49권5호
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• pp.675-689
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• 2014

본 연구에서는 앙상블 경험적 모드 분해법을 우리나라에 적용하여 봄 시작일을 정의하고, 이에 대한 시 공간적인 변화를 분석하였으며, 봄 시작일의 변동성을 분석하여, 봄 시작일에 영향을 미치는 요인을 파악하였다. 우리나라 평균 봄 시작일은 3월 11일로 나타났고, 연구기간 동안 2.6일/10년으로 빨라졌다. 봄 시작일은 일반적으로 위도와 고도가 높아짐에 따라, 그리고 해안에서 내륙으로 갈수록 늦게 나타났다. 우리나라 봄 시작일에 영향을 미치는 요인을 파악하기 위해 상관분석을 수행하였고, 전구평균기온, 북극진동(Arctic Oscillation, AO), 시베리아 고기압이 우리나라 봄 시작일과 유의한 상관관계를 나타냈다. 봄 시작일에 영향을 미치는 지수들을 대상으로 다중회귀분석을 수행하였고, 세 가지 변수가 모두 입력된 모형은 64.7%의 설명력을 나타냈다. 다중회귀분석의 결과 봄 시작일에 미치는 영향은 전구평균기온이 가장 크고, AO가 그 다음으로 나타났다. 우리나라 봄 시작일에 영향을 미치는 종관적인 요인을 파악하기 위해 기압장 및 바람장을 분석한 결과, 시베리아 고기압, 알류샨 저기압, 상층 기압골의 강도 및 위치에 따른 북풍계열 바람의 강도가 봄 시작일을 결정하는 주요 원인인 것으로 나타났다.