• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.15-22
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• 2012

A performance index of singalized intersections is a standard to optimize signal control variables and to manage traffic flow. Traffic delays is generally used to minimize the average delay time on intersections or networks, progression efficiency is used to improve travel speed of main cooridors or to provide transit signal priority. We manage traffic flows with only selecting one index between delays and progression according to the objective of traffic management and field characteristics. In real field, the driver's satisfaction is high in any performance criteria when the waiting time is shorter and the unnecessary stop in front of traffic is smaller. This paper aims to develop simulation model to represent real progression with concurrently considering delays and progression. In order to reflect an effect of level of traffic volumes and residual queues which don't be considered in prior progression model, we apply shockwave model with flow-density diagram. We derive Cell Transmission Model of Daganzo in order to develop the delay index and the progression index for the macroscopic simulation model. In order to validate the effect, we analysis traffic delays and progression efficiency with comparing this model to Transyt-7F and PASSER V.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.6
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• pp.34-42
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• 2014

This study is a fundamental research to determine the emergency evacuation roads considering road network function and connectivity. First of all, the functional aspects of the road networks are analyzed in the target area, Sejong city, by using degree centrality(DC) and closeness centrality(CC) from GIS based database. Secondly, how network connectivity makes a change in user's travel pattern and travel time and how it affects the whole network are analyzed using TransCAD simulation program. Finally, after performing cluster analysis of index, first and second emergency evacuation roads are determined by judging the characteristics of clusters. The results of this research will be helpful for making a decision to diminish secondary damages when confronting unexpected disasters.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.317-325
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• 2010

This study aims to deduct the extensive improvement types of leisure activities of private security agents using PPA technique and to examine the influence of leisure constraint on the index of participation. Through this process, this study consequently will draw the priority list of investment on the policy for improving the welfare status of private security agents. In this study, judgement sampling was applied to 6 security agencies located in Seoul, 2010, and 267 cases were used in the final analysis. Collected data went through factor analysis, reliability analysis, paired t test, PPA analysis, and regression analysis by using SPSSWIN 17.0. The conclusions were drawn as follows. In regard to the reliability, Cronbach's $\alpha$ was over .768. First, there was a difference between the preference rate and the participation rate which are the participation index of the private security agents' leisure activities. concentrate here in leisure types turned out to be fitness activities, walking/jogging, tourism, a day-long travel, and keep up the cood work in leisure types are movies, domestic tourist attractions, dating, eating out, personal relationship, watching sports, reading, karaoke, TV video watching, drinking etc. low priority in leisure types are water sports, hiking, biking, soccer, photography, ball games, sky sports, playing go/janggi, inline skates, and cooking. Second, the leisure constraint affects the participation index of leisure activities. As the personal constraint, and surrounding conscious constraint which are the subordinate factors of the leisure constraint get bigger, the participation index of favored leisure activities become lower. In contrast, when the difficulties such as structural constraint, time and economical constraint are overcome, participation index of leisure activities go on the rise.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.43-49
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• 2008

The objective of this research was to test a hypothesis that sprawl increases congestion, and so the estimated evacuation time become longer. For this, sprawl was thought to be poor accessibility so that vehicle miles of travel become longer. This research shows that the daily vehicle miles per lane mile that are thought to be an accessibility index had a strong and statistically significant relationship to the estimated evacuation time, while urban population density has no statistically significant relationship to the evacuation time. The result of this research recommends that we should consider sustainable land use patterns that decrease traffic demand by providing good accessibility.

• Journal of Information Technology Applications and Management
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• v.21 no.1
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• pp.177-184
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• 2014

This research analyzes the effects of factors on the demands for outbound to the countries such as Japan, China, the United States of America, Thailand, Philippines, Hong Kong, Singapore and Australia, the countries preferred by many Koreans. The factors for this research are (1) economic variables such as Korea Composite Stock Price Index (KOSPI), which could have influences on outbound tourism and exchange rate and (2) unpredictable events such as diseases, financial crisis and terrors. Regression analysis was used to identify relationship based on the monthly data from January 2001 to December 2010. The results of the analysis show that both exchange rate and KOSPI have impacts on the demands for outbound travel. In the case of travels to the United States of America and Philippines, Korean tourists usually have particular purposes such as studying, visiting relatives, playing golf or honeymoon, thus they are less influenced by the exchange rate. Moreover, Korean tourists tend not to visit particular locations for some time when shock reaction happens. As the demands for outbound travels are different from country to country accompanied by economic variables and shock variables, differentiated measure to should be considered to come close to the target numbers of tourists by switching as well as creating the demands. For further study we plan to build outbound tourism forecasting models using Artificial Neural Networks.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.762-768
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• 2010

The Bimodal Tram being developed in Korea is a new transit system that provides both benefits of rail and bus systems in terms of accessibility and fixed time schedule. The Bimodal Tram is expected to take an important role of transit system in Korea under the national strategy of transportation system such as 'Low Carbon and Green Growth' for the next generation. This study does define the key indices considered for a decision of introducing the Bimodal Tram system and develop a finalized index, BSI(Bimodal Score for Introduction), showing the level of Bimodal Tram system introduced at a city level. The transport/transit system varies depending on cities with respect to demographic characteristics, travel patterns, financial capabilities, etc. This study will help any cities where transport agencies are trying to introduce the Bimodal Tram as a new transit system.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.327-334
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• 2011

It is necessary that UGV(Unmanned Ground Vehicle) should generate a real-time travesability index map by analyzing raw terrain information to travel autonomously tough terrain which has various slope and roughness values. In this paper, we propose a local path planning method, $MA^*$(Modified $A^*$) algorithm, using DVGM (Directional Velocity Grid Map) for unmanned ground vehicle. We also present a path optimization algorithm and a path smoothing algorithm which regenerate a pre-planned local path by $MA^*$ algorithm into the reasonable local path considering the mobility of UGV. Field test is conducted with UGV in order to verify the performance of local path planning method using DVGM. The local path planned by $MA^*$ is compared with the result of $A^*$ to verify the safety and optimality of proposed algorithm.

• Parasites, Hosts and Diseases
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• v.57 no.4
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• pp.429-434
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• 2019

A complicated case of echinococcosis with multiple organ involvement is reported in a 53-year-old businessman who frequently traveled overseas, including China, Russia, and Kazakhstan from 2001 to 2007. The patient was first diagnosed with a large liver cyst during a screening abdomen ultrasonography in 2011, but he did not follow up on the lesion afterwards. Six years later, dizziness, dysarthria, and cough developed, and cystic lesions were found in the brain, liver and lungs. The clinical course was complicated when the patient went through multiple surgeries and inadequate treatment with a short duration of albendazole without a definite diagnosis. The patient visited our hospital for the first time in August 2018 due to worsening symptoms; he was finally diagnosed with echinococcosis using imaging and serologic criteria. He is now on prolonged albendazole treatment (400 mg twice a day) with gradual clinical and radiological improvement. A high index of suspicion is warranted to early diagnose echinococcosis in a patient with a travel history to endemic areas of echinococcosis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.291-303
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• 2012

In order to lead safe driving, it is better to provide dynamic and detailed information on how the driver using the relevant road should behave as concerning movements of individual car rather than providing monotone and static information of reducing of speed to unspecified drivers. Assuming road and communication of highway where real-time collection and transfer of information on vehicles and road traffic status is possible, the purpose of this study was to provide real-time safe distance by considering road traffic condition such as road condition and driving condition, travel speed and distance between preceding/following vehicles. We intended to provide basic information about dangerous situation by defining different values of condition based column ($C_{condition}$) in accordance with the road surface condition, based on which Real-time Safety Distance Index(RSDI) is to be calculated comprehensively reflecting speed of preceding and following vehicles, distance between vehicles, vertical alignment and road surface condition on the scope of expression column ($C_n$). We intended to enable the driver to secure safety by providing the calculated Real-time Safety Distance Index (RSDI) so that the driver can intuitively sense and sufficiently cope with a dangerous situation where collision of vehicles may occur. The calculated RSDI value is comprised of 30 unit columns and will be provided to the driver being divided into risk evaluation grades of 3 predetermined steps, 'warning', 'dangerous' and 'normal'.

• Journal of Korean Society of Transportation
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• v.27 no.2
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• pp.169-178
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• 2009

This study is aimed at identifying the association of commuting behavior with health for workers in the Korea Capital Region. The study surveyed a total of 1,285 commuters whose major work is deskwork-oriented; the authors obtained their health status on body form, blood pressure and cholesterol as well as their commuting behavior. The measures of the latter were comprised of a main commuting mode, a use term, out-of-vehicle time, total travel time, transit transfer, and alternative mode in order to identify the amount of physical activity obtained through commuting behavior. The results indicate that non-automobile commuters are positively associated to improve their health status, as compared to car commuters. Specifically, bus commuters and walkers had decreased weight, blood pressure, and cholesterol, while rail commuters are only correlated to relieving cholesterol. In addition, the measures for health are improved as out-of-vehicle time increases. For commuters who drive to work, their health status tends to be worse.