• Analytical Science and Technology
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• v.14 no.5
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• pp.451-457
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• 2001

Because liquids with high molecular weight such as mineral oil have low vapor pressure at room temperature, it is generally thought to be difficult to lose them to evaporation. However, when they are dispersed into air in small droplets during application in machining processes, their surface area becomes considerably higher. To determine the potential for metalworking fluids (MWF) filter losses, MWF mist was generated and collected on polyvinyl chloride (PVC) filters in test chamber. After collected MWF was exposed to clean air during designated period (range 10~240 minutes) and the filters were desiccated, losses were evaluated. As duration of clean air passing through PVC filter increased, loss of MWF gradually increased. MWF lost after 10 minutes ranged form 12.4 % to 21.8 % of the original loading mass, on average 53.3 % of the total loss. These results indicate that significant mass of MWF collected on PVC filters can be lost at the beginning of air sampling. Loss of MWF collected on PVC filter also occurred during desiccation without active airflow. In multiple regression to identify which factors influence the loss of MWF collected on PVC filter, both duration of air passing through PVC filter and MWF age (fresh vs. used) were significant predictor (p=0.0001). Therefore, workers' exposure to MWF measured method 0500, may underestimate true concentration. Further study is needed to develop a new method to quantify the workers' exposure to airborne MWF mist accurately.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.41-51
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• 2019

With the aging of the population and the slowdown of the job market, elderly workers make up a large portion of the construction workforce. Also, due to the nature of the construction industry, where outdoor work is frequent, the weather has a more sensitive impact on elderly workers than on younger ones. The study aims to analyze the degree of weather risks exposed to elderly workers in the construction industry using the measure of work loss days. To that end, construction accidents that affected 28,514 elderly workers in seven cities from 2012 to 2016 (a total of 12,789 days) were analyzed to calculate work loss days per different weather factors. The results show that the elderly workers were seriously affected when the temperature was between $-12^{\circ}C$ and $-10^{\circ}C$, humidity between 55% and 60%, precipitation between 128mm and 181mm, and wind speed between 5.5m/s and 6.5m/s, with the highest work loss days. The combined effects between the weather factors were also analyzed to identify the conditiosn that leaded to high work loss days of elderly workers. This study contributes to effective safety management and pleasant working environment between weather factors and shedding light on the relationship between weather factors and work loss days of elderly workers.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.270-284
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• 2009

There is a big attention to digital convergence products(DCP) nowadays. However, consumers' response on the DCP is not always positive. These products may not match consumers' value and consumers may not know how to use them, because the DCP is generally innovative products. DCP marketers should learn that why consumers do not purchase them. Thus, this paper examines and identifies the consumers' purchase-avoiding psychological factors and antecedents on DCP. In detail, It is empirically checked that how the relationship between purchase-preventing factors such as complexity, incongruence, uncertainty, and unreasonability and purchase-avoiding psychological factors such as dissonance, innovation resistence, and perceived loss is. Also, these purchase-avoiding psychological factors' influence on the purchase-intention is empirically checked. As results, complexity and incongruence have an effect on the innovation resistence significantly. Uncertainty and unreasonability influence perceived loss variable. Unreasonability also influences consumers' cognitive dissonance variable. Additionally, cognitive dissonance have an influence on innovation resistence positively, and such innovation resistence influence consumer's purchase-intention negatively. Therefore, marketers should think twice about the roles of these purchase-preventing factors before launching.

• Journal of Navigation and Port Research
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• v.30 no.1 s.107
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• pp.67-71
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• 2006

This study gathered the factors of supply chain risk through literature review, and measured the importance of risk factors recognized by domestic companies. The purpose and necessity of this study are as follows. First, supply risk factors were classified and explored through empirical studies about supply chain risk. Most of the previous studies concentrated on the meaning of supply chain risk, but only in terms of concept approach Second, to evaluate the importance of supply-chain risk recognized by the companies, AHP(Analytic Hierarchy Process} method was proposed in this paper. Finally, this study suggests implications for companies' efficient supply activity by measuring the importance of supply-chain through AHP(Analytic Hierarchy Process).

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.548-553
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• 2006

Activity-based productivity data can be used as an significant reference in many areas of project management such as performance evaluation and project planning. However, the existence of various factors influencing construction productivity makes it difficult to collect and analyze the productivity data. In the most of the domestic construction sites, there is no systematic method to collect and analyze the productivity data along with information on influencing factors; it is common to heavily rely on experience and intuition of field managers when dealing with construction productivity data. Therefore it is necessary to develop a management system for collecting and utilizing the productivity data as well as the factors influencing construction productivity. The main objective of this research is to define the construction productivity and its influencing factors at the activity level. In addition, methodologies on how to analyze the productivity data and to estimate productivity of future projects are proposed.

• 농업기술회보
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• v.48 no.5
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• pp.36-37
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• 2011

배를 저장할 때는 여러 가지 원인으로 손실이 발생할 수 있은데 원인은 크게 '생리적 장해'와 '저장병해'로 구분할 수 있다. 생리적 장해는 저장 중에 병원균의 침입 이외의 요인으로 발생되어 과실조직에 손상을 주는 것을 의미하며, 저장병해는 수상에서 또는 수확 전에 과피나 과경에 병원균이 침투하여 저장 중에 일정한 조건이 형성될 때 발병하는 현상을 말한다. 이 중에서도 근래에 많이 발생되어 농가에 많은 피해를 주고 있는 신고배 '얼룩과'는 저장병원균에 의해 발병하는 것으로 보고 얼룩과의 원인과 성상 그리고 억제 방법에 대해 설명하고자 한다.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.269-270
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• 2016

본 논문에서는 인버터의 정확한 전압 합성을 위해 인버터의 비선형성을 보상하는 기법을 제안한다. 인버터에서 데드타임, 스위칭 소자의 도통손실, 스위칭 지연 등의 성분들은 전압 합성에 비선형성을 유발한다. 제안된 방법은 이러한 요인들을 각 상별로 분석하고, 이를 보상함으로써 보다 정밀한 전압 합성을 가능케 한다. 이 방법의 유효성은 실험을 통하여 입증하였다.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.10a
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• pp.94-99
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• 1992

In this study , some factors such as mix proportion, type and dosage of high range water reducing admixture(HRWR) and natural pozzolanas influencing on the slump loss of high strength concrete(H.S.C) using HRWR were investigated for reducing the slump loss. The acquired results indicated that the slump loss of H.S.C was affected according to cement content, sand percentage and type and dosage of HRWR and fly ash was superior to ground granulated blast furance slag in reducing the slump loss of H.S.C.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.515-518
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• 2006

수많은 교각들이 규칙적으로 배치되어 있는 복개하천이나 하천종단교량 등의 경우 개별적인 교각의 후면부에서 발생하는 와류로 인한 에너지 손실이 누적되어 흐름에 큰 저항요인으로 작용한다. 격자기둥의 형상과 종방향 및 횡방향 배치간격이 배수시스템의 통수능에 미치는 영향을 파악하기 위해 본 연구에서는 사각형 및 둥근장방형 격자기둥에 대한 기초적인 수리 실험을 실시하고 그 결과를 분석하였다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.6-14
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• 2003

북한의 식량 상황이 악화된 근본적인 원인은 생산 주체에 대한 인센티브 부족, 농업환경을 보면 경작지 면적이 전체 20% 정도로 낮고, 무상기일이 135-180일로 짧으며, 토양의 비옥도 저하, 삼림파괴로 인한 토양 유실증가, 가뭄, 홍수, 태풍과 같은 자연 재해가 계속되고 있다. 농업 구조적인 요인들로는 농업에 투입되는 에너지 부족(연료, 비료, 농약, 전기 등), 농업 기계화율 정도가 높았으나 노후화에 따른 예비 부품 부족으로 인한 활용률의 저하, 양질의 종자확보 부족, 갖추고 있는 관개 시설의 노후화로 인한 관개시설 활용과 관수 효율의 저하, 농산물 수확 후 수송과 저장 과정에서 손실증가 등을 들수 있다. (중략)