• Journal of the Korean Society for Railway
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• v.16 no.1
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• pp.40-46
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• 2013

Based on Korean railway design standards, the thicknesses of the reinforced roadbeds of conventional and high speed railways are different, and so too, for the size distribution of the ballast particles. Accordingly, considerable cost would be required to increase operating speeds of conventional lines, in particular related to changing from a ballasted track system to a ballastless one. In this study, applicability of a roadbed which supports conventional ballasted track, for use as a ballastless track for a high speed rail line was examined. A reinforced roadbed for a conventional railway is 20cm thick, and the type of material used for a conventional reinforced roadbed is M-40 (crushed gravel for road embankments). A dynamics test was conducted to evaluate the occurrence of the permanent settlement of the track substructure. These results suggest that, without changes to the track substructure, an operational speed of 400km/h is feasible with a ballastless track. This result; however, is from laboratory experiments. Further studies, such as numerical analyses or field validation, are required.

• Korean Journal of Weed Science
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• v.2 no.2
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• pp.129-140
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• 1982

Herbicides were classified by two-dimensional ordination analysis based on the weed flora which was not controlled by application of a particular herbicide. The number of herbicide group was varied depending upon the weed community type and the experiment site. The technique of the two-dimensional ordination analysis gave more comprehensive informations about selecting of herbicides for increasing the herbicidal efficacy, for increasing the weed spectrum and for reducing the herbicide cost by mixing of herbicides. The two-dimensional ordination analysis could be used not only herbicide classification and selecting effective herbicide or herbicide combination but also can be used for the evaluation of systematic application of herbicides.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.183-193
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• 2016

In this study, design and performance of infiltration trench using woodchip as media for treating stormwater from highway were examined through field monitoring. Average reduction efficiency for TSS, COD, BOD, TN, and TP was 88%, 94%, 85%, 80%, and 75% respectively, which is similar to values reported by other studies and design manuals even though direct comparison is not possible due to different monitoring and design conditions. Mean field infiltration rate estimated by measuring the change of water depth inside the observation well was about 40mm/hr, and the time taken for complete infiltration was about 0.83days, which corresponds well with design criteria recommended by MOE guidelines in Korea. In addition, according to analysis of infiltration rate and reduction efficiency, effective rainfall depth applied for determining water quality volume(WQv), 5mm was found to be properly established as design criteria. Woodchip must be considered and included as an alternative media together with crushed rock and gravel into the design guidelines because it has more advantages in terms of weight, porosity, cost, and easiness of management than other media materials.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.95-106
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• 2012

The railway service in the Seoul metropolitan area is facing variety of l changes such as extension of service coverage, new construction, and introduction of express service which in turn causes changes on demands. The demand affects train operation characteristics (frequency of service, train formation) as well as on the congestion rate which is one of the major evaluation index in metropolitan area user service. For the efficient operation of the train, the relationship among the minimization of fleet number, operating cost, and service level has been analyzed. Using the Powersim, which is a system dynamics (System Dynamics) simulation program for realizing optimized simulation for train-formation, this paper identified that some stations of Gyeong-bu line exceeded limit congestion rate(150%) of a fleet already that means it is best to maintain current condition of the line; however, the Gyeong-in line and the Gwa-chon line showed no excess of the limit congestion rate so that it is possible to reduce 2-4 fleets of train for efficient operation. In addition, in case of Jang-hang line between Cheon-an and Sin-chang, a train consisting of 10 fleets provides services which is same formation of train for Gyeong-bu line. This study proved that the congestion rate will not rise greatly with only 4 fleets of a train for the service in Jang-hang line, and it is considered that a study for shuttle service between Cheon-an and Sin-chang is necessary.

• The Journal of Sustainable Design and Educational Environment Research
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• v.14 no.3
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• pp.9-17
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• 2015

In this paper, there are several analysis on G-SEED, Building Energy Efficiency Rating System, Energy Performance Index, Energy Saving Plan about how they are applied by classification and planning standard. The analysis result found out that G-SEED has low select percentage by having difficulties to managing and additional cost when the each class is selected. And also, Building Energy Efficiency Rating System in school is planed in comparably simple design and similar size and also mostly uses high efficient machines, which was in high lever comparing to the system in facilities in other uses. In the case of EPI, there are differences on acquiring grades by each region. Especially, Gyung-gi region has a low grade on architecture part comparing to other parts, which seems to acquire more grades by strengthen insulation performance. By the result from the three standards, many facilities has only formal plan to pass the required standard without considering specialities of each buildings, which has a tendency to have a pattern to have a minimum criteria. However, School has a symbolic building which has a obligation to be the base of the aim for growing green energy buildings and green education for students. Therefore, planning with understanding of specialities of the facility, having various and rational evaluation standards from the planning of the building is necessary.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.86-98
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• 2018

Since 2015, the Korea Expressway Corporation has provided predicted travel time information, which is reproduced from DSRC systems over the extended expressway network in Korea. When it is open for public information, it helps travelers decide optimal routes while minimizing traffic congestions and travel cost. Although, sutiable evaluations to investigate the reliability of travel time forecast information have not been conducted so far. First of all, this study seeks to find out a measure of effectiveness to evaluate the reliability of travel time forecast via various literatures. Secondly, using the performance measurement, this study evaluates concurrent travel time forecast information in highway quantitatively and examines the forecast error by exploratory data analysis. It appears that most of highway lines provided reliable forecast information. However, we found significant over/under-forecast on a few links within several long lines and it turns out that such minor errors reduce overall reliability in travel time forecast of the corresponding highway lines. This study would help to build a priority for quality control of the travel time forecast information system, and highlight the importance of performing periodic and sustainable management for travel time forecast information.

• Journal of the Korean Geotechnical Society
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• v.31 no.5
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• pp.23-33
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• 2015

In the present study, a ground heat exchanger was installed for each heat source in the system at the site to evaluate ground heat conductivity, constructability, and economic feasibility; the factors considered in the study included ground heat, groundwater, fillers (such as bentonite and pea pebbles) and the shape of the heat exchange pipe (e.g., U and D-U). The aim was to determine the ground heat exchanger appropriate for the geothermal system in the 3rd-phase construction of Incheon International Airport. A comparative cost analysis of the initial costs based on the above information showed that although the initial costs of the regular vertical closed loop-II and modified vertical closed loop were lower than those of the regular vertical closed loop-I, they could not be expected to deliver high economic efficiency from the viewpoint of constructability (filler injection, heat exchange pipe insertion). The initial costs proved to be higher in the case of Geohil.

• Child Health Nursing Research
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• v.20 no.4
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• pp.340-349
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• 2014

Purpose: The purpose of this study was to provide a critical assessment of evidence-based Korean pediatric research that can inform clinical practicability of, and future research on distraction interventions for pediatric procedural pain management. Methods: A critical review of evidence-based Korean pediatric research was conducted. Databases were searched to identify research that included an evaluation of a distraction intervention as an intervention for pediatric procedural pain management. The search yielded 68 studies. Results: From these studies, 14 were included for this review and all were recently published (2003-2014). Quasi experimental designs were most frequently used (n=12) and for 71.4% the focus was preschoolers. Audiovisual techniques were the most common form of distraction. In most studies clinical utility of the distraction intervention was not examined. Fairly consistent reductions in behavioral measures of pain in association with the distraction intervention were found but less consistent results were found for physiological measures. Conclusion: Lack of methodological rigor limits the evidence for distraction interventions to reduce pain and fear experienced by children during painful procedures. Further research to analyze the cost and time-effectiveness and to identify consumer and provider satisfaction with distraction interventions is needed to determine whether distraction interventions are clinically relevant.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.610-618
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• 2008

It is not easy to compare the treatment processes and find an optimum operating condition by the experiments due to influent conditions, treatment processes, various operational conditions and complex factors in real wastewater treatment system and also need a lot of time and costs. In this paper, the activated sludge models are applied to four principal biological wastewater treatment processes, $A_2O$(anaerobic/anoxic/oxic process), Bardenpho(4 steps), VIP(Virginia Initiative Plant) and UCT(University of Cape Town), and are used to compare their environmental and economic assessment for four key processes. In order to evaluate each processes, a new assessment index which can compare the efficiency of treatment performances in various processes is proposed, which considers both environmental and economic cost. It shows that the proposed index can be used to select the optimum processes among the candidate treatment processes as well as to find the optimum condition in each process. And it can find the change of economic and environmental index under the changes of influent flowrate and aerobic reaction size and predict the optimum index under various operation conditions.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1007-1028
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• 2014

This study aimed to explore the direction of development of agricultural safety and health system in Korea based on experience on Farmers' Occupational Health Services (FOHS) of Finland. In Finland additional and specialized Occupational Health Services (OHS) for self-employed farmers were developed and have been conducted by municipal primary health care centers with cooperation of National Centre for Agricultural Health (NCAH) of Finnish Institute of Occupational Health, Social Insurance Institute (SII) and Farmers' Social Insurance Institution (FSII). Based on the study, in order to activate the FOHS in Korea, the analysis results could suggest the development of four prerequisites. Firstly, center for farmers' safety and health like NCAH, which conducts surveillance on health and safety status, standardization of intervention contents and epidemiological research is needed in national institution. Secondly, development of evaluation tools with lower cost and difficulty like walk-through survey for checking status of systems of safety in the farms is needed. Thirdly, farmers' occupational health insurance which will be initiated on near future should be connected to preventive intervention programs like FOHS. Lastly, training and qualification of more local occupational health experts and units is needed.