• Proceedings of the KSR Conference
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• 2008.11b
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• pp.446-450
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• 2008

Urban transits of metropolises have been used by many citizens due to the merits of environment friendly traffic, mass transportation, safety and scheduled operation. It is very important to keep safety for the increased passengers. When the accidents as like fire occur, rapid evacuation from fire site is one of the most effective methods to decrease casualties. Furthermore, overseas buyers sometimes request the verification results of the passenger evacuation from rolling stock. In this study, algorithm for passenger flow analysis based on DEM(Discrete Element Method) is newly developed and made simulation program package. And, we applied it to the evacuation problem for urban transits. By using the developed program, we compared the simulation results of the effects of the location and size of door and elapsed time qualitatively and quantitatively.

• Journal of Environmental Impact Assessment
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• v.9 no.2
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• pp.143-153
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• 2000

This study was performed to investigate the heavy metal contents and distribution in soil, sediment, and rice from the downstream area of ManKyeong and DongJin River. Of the sites on Mankyeong river area, site M-1(Mokchon bridge) showed the highest average contents of Cd, Cr and Pb in paddy soil. In DongJin river area, site D-3(Munpo) and D-4(Gerjeonri) showed relatively high level of average contents of Cr, Pb and Zn in paddy soil. The average contents of heavy metals in brown rice from ManKyeong river area were 0.10mg/kg for Cd, 0.99mg/kg for Cr, 2.07mg/kg for Pb, 4.44mg/kg for Cu and 32.03mg/kg for Zn while those in brown rice from DongJin river area were 0.14mg/kg for Cd, 0.74mg/kg for Cr, 1.78mg/kg for Pb, 4.57mg/kg for Cu and 33.60mg/kg for Zn. Zn showed the highest transportation-rate from paddy soil to brown rice while Pb showed the lowest. From the results of heavy metal analysis in sediments, the average contents of Cd, Cr, Pb and Cu were generally high in site M-5(Euonri) and D-4(Gerjeonri), the most downstream sites in Mankyeong river and DongJin river, respectively.

• Environmental Engineering Research
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• v.24 no.1
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• pp.159-172
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• 2019

To investigate the influence of pollution events on the chemical composition and formation processes of aerosol particles, 24-h integrated size-segregated particulate matter (PM) was collected during the fall season at an urban site of Gwangju, Korea and was used to determine the concentrations of mass, water-soluble organic carbon (WSOC) and ionic species. Furthermore, black carbon (BC) concentrations were observed with an aethalometer. The entire sampling period was classified into four periods, i.e., typical, pollution event I, pollution event II, and an Asian dust event. Stable meteorological conditions (e.g., low wind speed, high surface pressure, and high relative humidity) observed during the two pollution events led to accumulation of aerosol particles and increased formation of secondary organic and inorganic aerosol species, thus causing $PM_{2.5}$ increase. Furthermore, these stable conditions resulted in the predominant condensation or droplet mode size distributions of PM, WSOC, $NO_3{^-}$, and $SO{_4}^{2-}$. However, difference in the accumulation mode size distributions of secondary water-soluble species between pollution events I and II could be attributed to the difference in transport pathways of air masses from high-pollution regions and the formation processes for the secondary chemical species. The average absorption ${\AA}ngstr{\ddot{o}}m$ exponent ($AAE_{370-950}$) for 370-950 nm wavelengths > 1.0 indicates that the BC particles from traffic emissions were likely mixed with light absorbing brown carbon (BrC) from biomass burning (BB) emissions. It was found that light absorption by BrC in the near UV range was affected by both secondary organic aerosol and BB emissions. Overall, the pollution events observed during fall at the study site can be due to the synergy of unfavorable meteorological conditions, enhanced secondary formation, local emissions, and long-range transportation of air masses from upwind polluted areas.

• Journal of Coastal Disaster Prevention
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• v.5 no.4
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• pp.173-182
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• 2018

As the research about increasing the efficiency of dredging soil transport, the technology, which reduce the friction between pipe wall and fluid in the pipe and disturbed generating pipe blockage, has been developed. So for the purpose of applying this technology to real construction site, main test has been tried at the real scale test in field. As a test result, this paper will show 30% flow efficiency increasing by permitted electro magnetic force to the pipe. And test result was evaluated as a ultra sonic velocity profiler. To propose the design technique and the execution manual of the high efficiency dredging material transport technic, this research have confirmed flow status changing depending on a soil material kind under electro-magnetic field and analyze the effect of electro-magnetic field which affects to each dredged soil material transportation. For achieving this research, EMF(Electro-Magnetic Field) generator is installed on the dredger(20,000HP) and through monitored flow status, dredging soil flow rate and sampled material specification is confirmed. Also dredger operating condition is measured and dredger power for soil transportation, hydraulic gradient and flow rate are compared, as transportation efficiency is calculated by this parameter, it is possible to check transportation efficiency improvement depending on each dredged soil material under electro-magnetic field. To verify the technique of dredged soil transfer using electromagnetic field, which is the core technique of the high efficiency dredged soil transfer, and the technique of expert system for pipeline transfer and the flow state. This could lead to a verification of transfer efficiency according to the characteristics of the dredged soil (sand, clay, silt) and the transfer distance (5km, 10km, 15km), which is planned to be used for a technology development of pump power reduction and long-distance transfer applying the high efficiency dredged soil transfer technology.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.73-80
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• 2008

ALINEA algorithm, which is one of the best on-ramp metering algorithms, was designed to control the traffic volume from on-ramp in order to maintain the optimal occupancy rate of the detectors installed downstream of the merge area. But, the reliability of occupancy rate estimated from the loop detectors, which are used most commonly in Korea, is relatively lower than other parameters such as speed and volume. Moreover, because occupancy rate depends on the length of loop detectors and site, lots of calibration work is required whenever they are installed in order to estimate the occupancy rate. Therefore, there exists room for improvement of ALINEA algorithm because only occupancy rate having some problems is considered as a control parameter in ALINEA algorithm. Practically it is difficult to measure or perceive the occupancy rate for traffic engineers and drivers. On the other hand, speed can be good alternative which can overcome the defect induced by using occupancy. In this study, occupancy based ALINEA algorithm is converted to speed based ALINEA assuming the linear relationship between density and speed.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.689-697
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• 2023

Purpose: The purpose of this study is to automatically extract information on underground facilities using a general-purpose smartphone in the process of applying the mini-trenching method. Method: Data sets for image learning were collected under various conditions such as day and night, height, and angle, and the object detection algorithm used the R-CNN algorithm. Result: As a result of the study, F1-Score was applied as a performance evaluation index that can consider the average of accurate predictions and reproduction rates at the same time, and F1-Score was 0.76. Conclusion: The results of this study showed that it was possible to extract information on underground buried materials based on smartphones, but it is necessary to improve the precision and accuracy of the algorithm through additional securing of learning data and on-site demonstration.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.530-547
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• 2018

This study examines the importance of location and transportation in the operation of small- and medium-sized hospitals in the rapidly changing clinical environment. Approximately 350 persons were surveyed for approximately 40 days from July-August 2017, and responses were analyzed using SPSS and AMOS Statistical Package for 335 parts excluding 8 parts of 343.The main research results were as follows: First, a hypothesis was adopted that the attractiveness of building materials will positively affect customer satisfaction. Second, the hypothesis that transport infrastructure has a significant impact on customer satisfaction was rejected. Third, the hypothesis that the building appeal will positively affect the site was supported. Fourth, the hypothesis that transport infrastructure will have a significant impact on location marketability was supported. Fifth, the hypothesis that location marketability will significantly impact customer satisfaction was supported. Sixth, the hypothesis that the relationship between the site and customer satisfaction with the relationship between the client and the client is explained is partly attributable to the fact that there is a partial function. The assumption that the relationship between traffic infrastructure and customer satisfaction was confirmed. The hypothesis that the relationship between traffic infrastructure and customer satisfaction was supported. This research focuses on small- and medium-sized hospitals located in Seoul, which does not include the recognition of patients' awareness of the location and transportation of small- and medium-sized hospitals. Moreover, this study has the limitation in analyzing patient satisfaction, rather than the objective data of the financial management performance of the hospital. The results of this study could provide the basis for selecting the future locations of health care facilities.

• Journal of the Economic Geographical Society of Korea
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• v.21 no.1
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• pp.20-33
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• 2018

Population distribution in urban space varies with transportation flow changing along time of day. Transportation flow is directly affected by the activities of urbanites and the distribution of related facilities, since the flow is the result of moving to the point where the facilities associated with their activities are located. It is thus necessary to analyze the spatio-temporal characteristics of the urban population distribution by integrating the distribution of activity spaces related to the daily life of urbanites and the flow of transportation. The purpose of this study is to analyze the population distribution in urban space with daily and weekly time bases using the building database and T-card database in the city of Seoul, which is rich in information on land use and transportation flow. For a time-based analysis that is difficult to grasp by general statistical techniques, a four-dimensional visualization method combining time and space using a Java program is devised. Dynamic visualization in the four-dimensional space and time allows intuitive analysis and makes it possible to understand more effectively the spatio-temporal characteristics of population distribution. For this purpose, buildings are classified into three activity groups: residential, working, and commercial according to their purpose, and the number of passengers traveling to and from each stop site of bus and subway networks in the T-card database for one week is calculated in one-minute increments, Visualizing these and integrating transportation and land use, we analyze spatio-temporal characteristics of the population distribution in Seoul. As a result, it is found that the population distribution of Seoul displays distinct spatio-temporal characteristics according to land use. In particular, there is a clear difference in the population distribution pattern along the time axis according to the mixed aspects of working, commercial, and residential activities. The results of this study can be very useful for transportation and location planning of city facilities.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.649-657
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• 2013

In this study, for a proposal of job-based IMDG code expert training model, the training cases of other countries were analyzed comparatively and a questionnaire-survey was conducted to find the needs of workers. As results of comparative analysis, various curriculums were operated by jobs of workers in USA and by kinds of dangerous goods or vehicles in UK, but a common curriculum was provided for various jobs of workers in Korea. It was analyzed that current domestic curriculum is not efficient, and the respondents demand expansion of training including provision of information via web-site as results of questionnaire survey. Therefore, in conclusion, after the shore workers were classified into three groups(on-site worker, office worker, & carrying worker), the customized training program of each group was suggested. Furthermore, this study proposed the regional operation of training course to meet regional demand on education including establishment of on-line curriculums.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1766-1784
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• 2011

In the past, station-area development projects were proceeded for modernizing the station facilities and improving the customer's convenience facilities by attracting private financing. But the site of station-are a development has a limitation that limits of benefits comparing with initial cost and absence of collateral by constructed the national property. For the advancing business value, merchandising facilities were adopted. There were many problems like coming the loss of city development opportunities. Now, station-area developments are considered the station and city plan. so, they are rapidly rised up the life in the station, need of making cultural space, improvement efficiency, combination and connectivity of transportation system and need of journey to Work Distance. Accordingly, this study suggests the station-area development projects by analysis of market conditions and forecast about housing and office that meets the trend of station-area development and secures feasible business value.