• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.3-15
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• 2013

The purpose of this study is to propose a methodology for operating variable speed limit (VSL) strategies in freeway work zones. A notable feature in this study is to incorporate a multi-criteria decision making process into deriving better VSL strategies. Decision criteria in this study include operational efficiency, safety, and environmental impacts. Travel speed, acceleration noise, and CO2 were used as performance measures for evaluating VSL strategies. A multi-criteria value function was developed through an analytical hierarchical process (AHP) for representing expert's knowledge. Then, a variety of VSL operations scenarios were investigated utilizing a microscopic traffic simulation suite, VISSIM. The proposed methodology would be useful in supporting more efficient, safer, and more environment-friendly traffic operations and control in freeway work zones.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.39-49
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• 2010

Although many studies have been carried out on the pattern of behavior of drivers which result from the provision of traffic information, there have been few detailed studies on the composition of message, method for message expression, timing of provision, point of provision, media for provision, changes by traffic condition, etc. This study was intended to provide an insight into the changes in the characteristics related to the provision of information by analyzing how the patterns of information utilization change depending on the traffic condition and reclassifying such patterns according to the characteristics of media. Unlike the existing studies, this study adopted the traffic condition, using rate of information media, and the correlation coefficient label as the basis for information media classification, and categorized them into passive utilization media, active utilization media, and past experience in order to ensure the statistical reasonability. The categorized using rate of information media and traffic condition was found to have a positive(+) correlation with the travel speed in the case of passive utilization media during both consecutive holidays(Korea's traditional Thanksgiving day) and weekends, but had a negative(-) correlation with the positive utilization media and past experience. The rate of decision to take a detour based on the past experience was high at the condition of congestion or slow during both consecutive holidays and weekends, but the rate of decision to take a detour through passive utilization media was high in a smooth traffic. In other words, if the traffic condition worsens, using rate of passive utilization media would be low while the diversion rate would be high which uses the active utilization media and past experience. Therefore, it should be established to suit the traffic condition and media characteristics for strategies of traffic distribution through drivers' diversion behavior on weekends and consecutive holidays.

• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.91-106
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• 2010

Recently, interest in supply chain management is rising along with the increasing oil prices and traffic congestion. In particular, people started studying the issue, but realized that advantageous strategies for suppliers and retailers are not always advantageous to a carrier. Therefore, in this study the atuhors set up a simulation scenario to understand delivery vehicle routing problems under various inventory policies, namely Economic Order Quantity (EOQ) and Periodic Order Quantity (POQ) and network configurations. First, the authors made a virtual supply chain. Then they analyzed characteristics of delivery vehicle routing under various inventory policies (EOQ and POQ) and network configurations. As a result, the POQ inventory policy decreases the number of vehicles, the number of drivers, and the service time of vehicles. Also, the centralized network increases the load factor of vehicles and decreases the service time of vehicles. In other words, the centralized network and the POQ inventory policy are better for the carrier. These results show a savings of 15,556,806 won ($13,389.10) in a month: a reduction of 17%.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.153-159
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• 2016

Gwangyang traffic safety designated area is composed of 3 fairways (Deep water fairway, inbound fairway, and outbound fairway). However, inbound vessels can't use this passage because of Samyeo rock and artificial fishing banks in inbound route. The problem with the rocks and artificial fishing banks has been raised by ship navigators and authorities of the port. This research is about the safety evaluation and management plan of the passage, and we conducted maritime traffic simulation using a model based on a ship operator risks. As a result, assuming that future marine traffic volume is the same as the present, and if the ship operators use 3 fairways and not two, it showed risk reduction of 46.4 % (vessels over 50,000 DWT using DW route) and 57.1 % (vessels over 10,000 DWT using DW route). Also, in a traffic volume condition which is the same as the present, to induce vessels over 50,000 DWT to use DW route is effective in mitigating of risks. Meanwhile, in a condition which increased the traffic volume by 150 %, it is more effective to induce vessels to use DW route. This research is the result of analysis using the model based on ship operator risks, and not cost-effectiveness analysis on the removal of Samyeo rock and artifical fishing banks. This research is expected to be used on setting up the sea route and management plan (particularly, restriction on passing DW route).

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.44-55
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• 2013

Intelligent transportation systems allow us to have valuable opportunities for collecting reliable wide-area coverage traffic and weather data. Significant efforts have been made in many countries to apply these data. This study identifies the critical points for classifying rain intensity by analyzing the relationship between rainfall and the amount of speed reduction. Then, traffic prediction performance by rain intensity level is evaluated using relative errors. The results show that critical points are 0.4mm/5min and 0.8mm/5min for classifying rain intensity (slight, moderate, and heavy rain). The best prediction performance is observable when previous five-block speed data is used as inputs under normal weather conditions. On the other hand, previous two or three-block speed data is used as inputs under rainy weather conditions. The outcomes of this study support the development of more reliable traffic information for providing advanced traffic information service.

• Journal of Cadastre & Land InformatiX
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• v.53 no.1
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• pp.21-36
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• 2023

Activity-based modeling systems have increasingly been developed to address the limitations of widely used traditional four-step transportation demand forecasting models. Accordingly, this paper introduces the Activity-BAsed Traveler Analyzer (ABATA) system. This system consists of multiple components, including an hourly total population estimator, activity profile constructor, hourly activity population estimator, spatial activity population estimator, and origin/destination estimator. To demonstrate the proposed system, the emission impact of land use changes in the 5-1 block Sejong smart city is evaluated as a case study. The results indicate that the land use with the scenario of work facility dispersed plan produced more emissions than the scenario of work facility centralized plan due to the longer travel distance. The proposed ABATA system is expected to provide a valuable tool for simulating the impacts of future changes in population, activity schedules, and land use on activity populations and travel demands.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.3
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• pp.211-217
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• 2001

Chun-chon city is the area that is estimated to be damaged by breaking of Dam by a flood among several natural disaster. If so, what is the way that minimize the damage\ulcorner There are many ones but it may be best that we take shelter from it before the breaking of Dam. Then when must we do\ulcorner By what instrument can we minimize the damage of people. And how do we compute the time\ulcorner In this study, using buffering, overlap and network, GIS ability based on ARC/INFO. I chose six routesto take shelter outside of Chun-chon city, calculated the traffic volume of each ones, and estimated the time for decentralization of risks.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.405-420
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• 2014

To investigate geochemical characteristics of soil and atmospheric environments by anthropogenic source, we have analyzed and determined heavy metal concentrations of the surface soils beneath roadside trees and leaves of Platanus occidentalis from 52 points in Seoul during autumn 2001. For comparison of the contents of heavy metal for the soil and leaf, we have analyzed heavy metal contents of the surface soils beneath roadside trees and leaves from 2 points in rural area of Yesan during the same time period. The composition of heavy metals of soils are relatively high for Cd, Co, Cr and Ni in industrial area (IA, Industrial Area) and high for Cu, Pb and Zn in heavy traffic area (HTA, Heavy Traffic Area). The heavy metal contents of rural area in Seoul are higher than those in Yesan. The differences of chemical compositions between the washed and unwashed leaves are high for Cd, Cu, Pb and Zn in the HTA. The element couples of Cd-Co, Cr-Ni and Pb-Zn for the soils had shown a good correlation and their contamination sources could be similar. The relationship for Pb-Cu and Cu-Zn showed good correlation in Platanus leaves. The relationship between soils and unwashed leaves show a good correlation for Cr, Cu, Pb and Zn but low correlation for Cd, Co, Fe, Mn and Ni. It is thought that the Cr, Cu, Pb and Zn were derived from contaminants of soils, whereas Cd, Co, Fe, Mn and Ni were originated from atmospheric source. From the spatial variations of elements for soils and leaves, Ni and Cr were dominant in the soils of IA and Cd, Cu and Zn were dominant in those of HTA. The Contamination by Cd-Pb and Cu-Zn in unwashed leaves were analyzed to show similar patterns. Using the enrichment factors (EF) of heavy metals in unwashed leaves, the EF sequences were to be Cu, Zn, Pb, Mn, Co, Ni, Cd and Cr. We identified that Cu, Zn, Pb and Mn were most problematic of environmental hazard in Seoul.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.61-74
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• 2009

Traffic accident risk index Computation model's development apply traffic level of significance about area of road user group, road and street network area, population group etc.. through numerical formula or model by countermeasure to reduce the occurrence rate of traffic accidents. Is real condition that is taking advantage of risk by tangent section through estimation model and by method to choose improvement way to intersection from outside the country, and is utilizing being applied in part business in domestic. However, question is brought in the accuracy being utilizing changing some to take external model in domestic real condition than individual development of model. Therefore, selection intersection estimation element through traffic accidents occurrence present condition, geometry structure, control way, traffic volume, turning traffic volume etc. in 96 intersections in this research, and select final variable through correlation analysis of abstracted estimation elements. Developed intersection design model taking advantage of signal type, numeric of lane, intersection type, analysis of variance techniques through ANOVA analysis of three variables of intersection form with selected variable lastly, in signal crossing through three class intersection, distinction variable choice risk in model, no-signal crossing risk distinction analysis model and so on develop.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.123-125
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• 2011

울산항은 1996년 9월부터 입출항 선박의 항행안전을 위해 VTS 시스템을 설치운영하고 있으나 많은 선박통항량과 위험화물 운송선박의 잦은 운항으로 여러 가지 위험요소가 상존하고 있는 개항장이다. VTS 시스템은 레이더의 자동물표추적장치에 의한 데이터, PORT-MIS의 선박관련 데이터 등 많은 정보들이 분산 처리되어 관제사에게 제공되고 있으나 최근 선박에 설치 운영되고 있는 선박자동식별장치(AIS)에 의해 선박의 정보들이 더욱 신속하고 정확하게 처리되는 것으로 평가되고 있다. 그러나 인위적인 과실에 의한 AIS의 오류정보들과 원활하지 못한 데이터통신에 의한 데이터 누락현상에 의해 VTS 시스템 운용에 막대한 영향을 초래하고 있다. 이러한 인위적인 과실에 의한 AIS의 오류 데이터는 PSC 검사관들의 적극적인 개선의지로 정책적인 계도작업을 수행하고 있으므로 점차 개선될 것으로 기대된다. 따라서 본 연구에서 AIS의 원활하지 못한 통신망에 의한 데이터 누락 현상에 의한 VTS 시스템에서의 영향을 조사 분석하고 이에 따른 개선 방안을 제시하고자 한다.