• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.420-427
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• 2017

Recently, the depletion of fossil fuels, global warming and environmental pollution have emerged as a worldwide problem, and studies of new renewable energy sources have been progressed. Among the many renewable energy sources, the use of bio fuel has the potential to displace fossil fuels due to low price, easy to handle, and the abundant sources. Pyrolysis oil (PO) derived from waste wood and sawdust is considered an alternative fuel for use in diesel engines. On the other hand, PO is limited to diesel engines because of its low cetane number, high viscosity, high acidity, and low energy density. Therefore, to improve its poor properties, PO was mixed with alcohol fuels, such as ethanol. Early mixing with ethanol has the benefit of improving the storage and handling properties of the PO. Furthermore, a PO-ethanol blended fuel was injected separately, which can be fired through pilot-injected diesel in a dual-injection diesel engine. The experimental results showed that the substitution of diesel with blended fuel increases the amount of HC and CO, but reduces the NOx and PM significantly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.68-78
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• 2017

The purpose of this study was to identify the influence of the individual-level and community-level factors in the ecological model on walking and to provide the basic data for a strategy that can increase walking for health promotion of adult workers. By combining the primary data of community health survey (CHS) (2011-2013) with the Korea national statistics annual book (2011-2013), the regional level variables were extracted from 253 municipal districts and the convergent big data with the hierarchical structure was produced. As a result, the increase in budget expenditure for public order and safety in social and cultural environment factors, the increase in budget expenditure for national and community land development in the leisure environment factors, and the number of buses in the transportation environment were increased by walking. In conclusion, walking was increased by the development of a community environment and bus transportation besides individual characteristics and behavior. Therefore, improving environment and public transportation will increase physical activity, such as walking, which will increase the health expectancy in community citizen workers.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.1
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• pp.43-50
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• 2012

The safety of cosmetics or cosmetic ingredients on human skin is generally evaluated by visual assessment but some early subtle skin changes may not be noticed by the naked eyes. Thus, the present study was conducted to detect skin reactions induced by mildly irritating cosmetic ingredients by using a laser Doppler perfusion imager (LDPI) method that measures blood flow, a $Vapometer^{(R)}$ that measure strans epidermal water loss (TEWL), and a spectrophotometer that measures the skin color as the erythema values ($a^*$). Visual assessment showed that all tested oils and humectants except propylene glycol belong to the low skin irritation ranges (grades 0+ to 2.9+) while all tested surfactants and propylene glycol belong to the moderate-to strong-skin irritation ranges (grades 3+ to 5+). Among three instrumental methods, TEWL assessment appeared to be more sensitive than spectrophotometric or LDPI method and suitable for the detection of subtle skin response invisible to the naked eye (grades 0+ to 2.9+). Skin reactions of grade 3+ to 5+ could be detected by all three instrumental methods. In conclusion, the current study suggested that the sub-clinical skin reactions due to mild irritants contained in cosmetics can be best assessed by TEWL measurements.

• Journal of Korea Water Resources Association
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• v.44 no.9
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• pp.765-776
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• 2011

Flood discharge capacity in a dam downstream reach has been decreased after dam construction because of the river cross section reduction impacted by farm lands, sand-bars and parking lots, etc. in river flood plains. Those obstacles being in the river inside areas have caused negative influences to the dam operation policy. Therefore, the dam downstream river improvement work associated with the dam operation improvement plan is under construction for removing reduction factors on the dam effective storage, assuring flood safety in the dam downstream river and incrementing dam operation benefits. But the project has issued some problems such as project feasibility, economic evaluation, cost allocation and benefit share, etc. Since a dam enterpriser has not committed such kind of project before, it is necessary to set up an objective analysis process and a quantitative financial valuation. This study examines the measurable economic benefits and the cost allocation of the project for the fairness between benefit owners (central government and water electricity enterprisers). As a result, the total economic benefit from 3 dams (Imha, Daechung and Youngdam Dam) accounts for 14.41 Billion Won/year. The financial valuation of K-water as a project enterpriser is approximately estimated at 40% of the total value and the government is 60%.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.179-188
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• 2014

Social overhead capital (SOC) facilities are being threatened continuously by abnormal climate events that are increasing globally. For disaster response, rapid decision making on evacuation routes and other matters is critical. For this purpose, spatiotemporal information that combine data on disasters and SOC facilities needs to be utilized. This information is separately collected by government agencies and public organizations, and is not managed in an integrated manner. For rapid disaster response, an integrated management of separately collected disaster data and the creation of such information as the safety and damages on SOC facilities are required. To achieve this goal, it is essential to build inventories that integrate all the related information to support decision making indispensable for disaster response. In this study, a development plan for an integrated inventory management system based on the management and connection of inventories to support rapid decision making for disaster response is proposed. This system can collect and standardize data related to disasters and SOC facilities that are being managed separately and provide integrated information in line with the needs of users. The proposed system can be used as a decision making tool for proactive disaster response.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.455-465
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• 2017

This study focuses on design development and verification through virtual simulation based on 3D model data in the cloud platform as a method of utilization of engineering technology of design in the fourth industrial revolution era. The goal of research is to develop and examine a design for the needs of the target that has never been met before through virtual simulations that can be conducted in practice. As a research method, we analyzed secondary data to identify the needs of the target, and did literature research for the ergonomic data and target body development stages. In addition, the design development process of this study was shown meaningful result in design, structure, safety, material, durability through loop test of 7 virtual simulations. This study can be applied to the automated process system based on 3D model data in the 4th industrial revolution era and can be used as an element of the cyber physics system for the additional research.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.128-139
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• 2017

Railway is one of the public transportation systems along with shipping and aviation. With the recent introduction of high speed train, its proportion is increasing rapidly, which results in the higher risk of catastrophic failures. The wheel bearing to support the train is one of the important components requiring higher reliability and safety in this aspect. Recently, many studies have been made under the name of prognostics and health management (PHM), for the purpose of fault diagnosis and failure prognosis of the bearing under operation. Among them, the most important step is to extract a feature that represents the fault status properly and is useful for accurate remaining life prediction. However, the conventional features have shown some limitations that make them less useful since they fluctuate over time even after the signal de-noising or do not show a distinct pattern of degradation which lack the monotonic trend over the cycles. In this study, a new method for feature extraction is proposed based on the observation of relative frequency energy shifting over the cycles, which is then converted into the feature using the information entropy. In order to demonstrate the method, traditional and new features are generated and compared using the bearing data named FEMTO which was provided by the FEMTO-ST institute for IEEE 2012 PHM Data Challenge competition.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.207-214
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• 2017

High voltage electric power transmitter GIS(Gas Insulated Switchgear) above 72.5kV needs to satisfy domestic Korean peninsular standard(ES-6110-0002) in KEPCO with respect to normal and special operation conditions which include internal gas pressure, dead weight, wind and seismic load. Some other requirements not described in Korean standard can be applied from other international standards such as IEC(International Electronical Committee) 62271-203 and 62271-207. The GIS is a kind of pressure vessel structure made of aluminum and filled with SF6 gas of internal pressure 0.4~0.5MPa. Finite element analysis of GIS is performed with such operational loads including seismic loading and the stability and reliability is determined according to ASME BPVC(Boiler and Pressure Vessel Code) SEC. VIII standard where the allowable stress level of the pressure vessel is suggested. The result shows that the stress of GIS is satisfied the allowable stress level and the safety factor is about 2.3 for Korean peninsular standard.

• Journal of Life Science
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• v.20 no.10
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• pp.1525-1531
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• 2010

The principal objective of this study was to investigate the effects of silkworm sericin extract supplementation on the improvement of lipid compositions, blood glucose levels and enzyme activities in the serum of dyslipidemic rats. The rats were fed the experimental diet for 5 weeks. Concentrations of total cholesterol, atherosclerotic index, LDL-cholesterol, triglyceride (TG), phospholipid (PL), free cholesterol, cholesteryl ester ratio and blood glucose in serum were higher in the dyslipidemic group (group HCW) and cholesterol-plus-silkworm sericin extract intake group (group HCS) than those in the control group (group BW, basal diet-plus-water). However, the concentrations of total cholesterol, atherosclerotic index, LDL-cholesterol, TG, PL, free cholesterol, cholesteryl ester ratio and blood glucose level in serum were lower in group HCS than those in group HCW. On the other hand, the HDL-cholesterol level and the ratio of HDL-cholesterol to total cholesterol in group HCS were higher than in group HCW. The activities of alkaline phosphatase (ALP) and aminotransferase (AST & ALT) in serum were lower in group HCS than in the dyslipidemic group HCW. From the above results, it was suggested that silkworm sericin extract intake was effective in the prevention and improvement of lipid components, blood glucose level and enzyme activities in the sera of dyslipidemic rats.

• Journal of Environmental Science International
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• v.17 no.9
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• pp.1005-1013
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• 2008

In this study, in order to analyze the air quality of the indoor environments of schools, we measured the indoor, outdoor and personal exposure concentration level of $PM_{10}$ for 40 classrooms(20 old, 20 new) in chungnam area from June 22 to July 19 and from November 21 to December 30, 2003. 1. Old classrooms contained more dust than new classrooms; the average of respirable dust is $43.27\;{\mu}g/m^3$ for new classrooms while $53.38\;{\mu}g/m^3$ for old one. The exposure concentration level of respirable dust in new classrooms were in summer higher outdoors than indoors. The values were indoors $46.71\;{\mu}g/m^3$, outdoors $50.46\;{\mu}g/m^3$, and personal $41.62\;{\mu}g/m^3$. Meanwhile in winter indoors had a higher concentration level than outdoors, the values being indoors $39.11\;{\mu}g/m^3$, outdoors $34.86\;{\mu}g/m^3$, and personal $49.01\;{\mu}g/m^3$. 2. Cr concentration level within dust was slightly higher in summer indoors ($101.50{\pm}32.10\;ng/m^3$) and outdoors ($100.89{\pm}35.18\;ng/m^3$) than winter indoors ($85.80{\pm}48.95\;ng/m^3$) and outdoors ($74.43{\pm}38.93\;ng/m^3$), but in personal concentration level, winter was higher. The results of this research show insufficient understanding of health risks from indoor air pollution, and shows possible health problems to students from school indoor air pollution. As such, a logical and systematic education program for students about the importance of indoor air quality should be carried out. Also the results of $PM_{10}$ concentration level measurements emphasize the need for regular measurements of indoor / outdoor and personal concentration level. New classrooms in particular needs to be used after measuring pollutants and safety, and requires installation of a ventilation device in all classrooms to improve air quality.