• Korean Journal of Construction Engineering and Management
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• v.21 no.6
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• pp.16-26
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• 2020

Road Pavement Maintenance Work is generated in a variety of different field conditions, and it is difficult to calculate the construction cost because there are no detailed criteria when preparing the estimated construction cost. Unlike new pavements, Road Pavement Maintenance has to be constructed with operating vehicles, and there are many differences in productivity depending on urban areas, limited work hours, night-time, construction area, etc. To compensate for this, the standard for calculation of construction cost provides additional charges for the number of lanes, residential areas, working hours, and night work, but it applied differently depending on construction officials. In this study, construction cost estimation standards that can properly reflect the conditions of the site was investigated for major types of Road Pavement Maintenance work. The site was investigated and analyzed mainly for many construction sites with 'overlay of asphalt after cutting', 'restore surface', 'repair of pavement', and 'recovery of roadway'. The criteria for the application of construction volume separately according to working hours, public places, and land area including extra charges for basic downtown and residential area. The hours of operation were divided into three types(7 hours, 5 hours, 3 hours) excluding movement and preparation time, and each type provided a coefficient for dividing the area of the construction site into five types. The construction cost calculation method based on the construction purpose is site conditions is proposed accordingly, and it is deemed that a plan for the designer to calculate the construction cost has been prepared in consideration of the site conditions.

• Journal of the Korean Society for Railway
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• v.16 no.5
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• pp.418-429
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• 2013

This study assesses the appropriate amounts and applicable ranges of travel time values for freight transport modes in Korea. The findings suggest that it is possible to determine appropriate sizes and applicable ranges of travel time values of goods set for road transport mode (i.e. truck), whereas those for railway, inland waterway, marine, and air transport modes are not as easily estimated. The adequate travel time value for trucks is 20,000won/vehicle hour, and the application range of travel time value of trucks is 17,000~23,000won/vehicle hour considering other variables. The most adequate estimation method of determining the travel time value for road transport is the wage rate method, whereas the marginal rate of substitution method is more rational for railway, inland waterway, marine, and air transport modes considering the application purpose and characteristics of the goods transported.

• The Journal of Sustainable Design and Educational Environment Research
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• v.16 no.1
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• pp.20-29
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• 2017

In order to prove the hypothesis that the element of school location planning - the density of development, availability of various private institutes, the location of school, the type of school district, the distance to nearby schools, the existence of communal areas, the pedestrian street, the number of road lanes - affects the increase and decrease of the number of students in the long term, we examined the tendency of the number of long-term (24 years). The results of the analysis are as follows: First, the development factors such as development density, location of school, type of school district, distance from neighboring schools, separation of pedestrians and cars are clearly related. Second, the planning factors such as location of private school and installation of pedestrian-only street seem to be related to each other. Third, the number of road lanes and element of "communal area" is irrelevant. This study is limited to generalization of five new metropolitan cities in the metropolitan area, and it is necessary to further elaborate the analysis factors and evaluation criteria.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.55-63
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• 2018

Although there has been a great change in the Chinese logistics industry, there have been few studies on the research trends of logistics in China. Existing research has been conducted on subdivision topics such as transportation efficiency, warehouse location and port efficiency. In this study, the research trends of logistics in China from 2000 to 2017 were analyzed using SNA method. The data were collected from foreign journals and a total of 82 related papers were used for analysis. The first period (2000-2008) was derived from the top keywords such as "Globalization", "Hong Kong", "FDI" and "outsousing". The results of the second period (2009-2013) were derived from keywords such as "international trade" and "reverse logistics", and in the third period (2013-2017) "3PL", "warehousing", "railways" "supply chain", "economic", "port" and "Belt and Road" The analysis of China's logistics using SNA method shows that the research trend of China's logistics is evolving as China is changing rapidly under the globalization context.

• International Journal of Highway Engineering
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• v.7 no.3 s.25
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• pp.93-100
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• 2005

Rock produced in situ has been used as the road construction materials in consideration of economies. However, because sedimentary rock is rapidly weathered, it is hard to decide appropriateness of quality specifications. This study aims at evaluation of usability for sub-base of muddy stone produced in situ. Test results show that the abrasion ratio is fitted for specifications, but weight loss in 37.5$\sim$16mm after Los Angeles abrasion test shows 47% in muddy stone in comparison with 20$\sim$30% in gneiss and sandstone. The soundness of aggregate shows higher value in muddy stone than in gneiss and sandstone. The weight loss from accelerated weathering test due to freezing and drying show 58% in muddy stone in comparison with 308$\sim$21% gneiss and sandstone.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.5
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• pp.494-502
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• 2011

Bimodal tram is designed to run on a dedicated path in automatic mode using a magnetic track system in order to realize a combination of the accessibility of a bus and the constant regularity of a railroad. This paper presents design and test results of the series hybrid propulsion system of the bimodal tram on both test track and public road, which uses CNG (Compressed Natural Gas) engine and Lithium polymer battery pack. This paper describes the real-time data measuring equipment for the series hybrid propulsion system of the bimodal tram. Using this measurement equipment, the performance of the prototype vehicle's driving on test track and public road was verified and the fuel consumption and the efficiency of CNG engine have been investigated.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.867-878
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• 2021

Recently, there has been active research on smart street lamps that can collect real-time traffic data and provide traffic information by attaching images and radars to road lighting facilities. Smart street light technology can detect, identify, and provide dense information compared to existing technologies. In order to effectively utilize the smart streetlight as a high-resolution information delivery medium, a branch-type operation strategy that is different from the existing centralized operation strategy is required. This study presents dynamic information delivery strategies, release strategies, and their criteria for various purposes in a spatial range, separated by the context before and after the occurrence of smart street lights-based accidents. Through this, it is expected that smart road lighting facilities can be used more effectively.

• Economic and Environmental Geology
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• v.33 no.2
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• pp.101-109
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• 2000

The gravity measurement has been carried out to study the deep geologic structure at 331 gravity stations with an interval of 1∼1.5 km along the national road which crosses the southern part of the Korean peninsula from Pohang to Manripo. The Bouguer gravity anomalies were obtained from the observed gravity values, and interpreted by means of upward continuation using FFT (Fast Fourier Transform), Fourier-series method and nonlinear 2-D inversion method to determine the depths of Conrad and Moho discontinuities. The linear regression relations between elevations and gravity anomalies were also obtained to test isostasy in the study area. The depth of Conrad discontinuty is 13km between Pohang and Daegu, 16.5 km between Kimchon and Okchon, 9.7 km between Okchon and Daejeon, and 16.3 km near Manripo. The depth of Moho discontinuty is 32km between Pohang and Daegu, 35 km between Kimchon and Okchon, 28.7 km between Okchon and Daejeon, 40.5 km between Daejeon and Kongju, and 34.5 km between Kongju and Manripo. The result of testing isotasy indicates that the crust of this area seems to be not in perfect isostatic equilibrium but in a little undercompensated sate.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.87-93
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• 2014

PURPOSES : To evaluate the feasibility of cut waste fishing net as a reinforced fiber for concrete. METHODS : Strength characteristics of fiber reinforced concrete using waste fishing net were investigated. The cut waste fishing nets with 4~5cm length were putted into the soil-cement and cement concrete for pavement slab. RESULTS : Compression and tensile strength of fiber reinforced concrete using waste fishing net were increased. CONCLUSIONS : It was concluded that cut waste fishing net can be used as a reinforced fiber for cement concrete. However, sometimes using cut waste fishing net leads to decrease the strength; therefore, further researches are needed for real project.

• Journal of Environmental Impact Assessment
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• v.27 no.5
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• pp.431-446
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• 2018

In this study, chemical characteristics of $PM_{2.5}$ samples collected in an agricultural area in Nonsan of Korea were investigated focusing on of black carbon, 3 inorganic ions and 22 trace elements. It was found that the relative error and relative standard deviation of many trace elements fell below 10%, which indicates good analytical accuracy and precision. The mean values of $PM_{2.5}$ in an agricultural area were exceeded by new Korean air quality standard of March 2018. The concentration of $PM_{2.5}$ was well correlated with those of black carbon and ions. The concentrations of trace elements were in a wide range of seven orders of a magnitude. Based on these $PM_{2.5}$ data sets, a total of 6 sources were identified using PMF (Positive Matrix Factorization; secondary aerosol (34.4%), soil/road dust (20.1%), biomass burning (16.9%), incineration/fuel combustion (13.2%), vehicle exhaust(12.2%), sea-salt (3.17%). Results of our study indicate that it is very important to control illegal burning activities in agricultural area.