• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.243-250
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• 2014

Modern roundabouts referred to as relatively safer and more efficient traffic facility than the signalized intersections have been recently deployed and operated and accordingly more research efforts to improve its safety and efficiency have been made so far. This paper introduces a new traffic information system named as Smart Roundabout coupled with Connected Vehicle technique like Vehicle-to-Roadside communication, which has not been attempted before and evaluates its performance with a microscopic simulation model, VISSIM. The proposed system functions to collect driving information of circulating vehicles in the roundabout such as location, speed, critical headway, etc. and help approaching vehicles decide whether to enter the roundabout with an on-board equipment instrumented in the individual vehicle on the basis of calculated gap acceptance of interest. This new system is expected to secure more safety and increase the capacity of the modern roundabout.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.145-153
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• 2008

Existing shortest-path algorithms mainly consider a single attribute. But traveler actually chooses a route considering not single attribute but various attributes which are synthesized travel time, route length, personal preference, etc. Therefore, to search the optimal path, these attributes are considered synthetically. In this study route searching algorithm which selects the maximum utility route using discrete choice model has developed in order to consider various attributes. Six elements which affect route choice are chosen for the route choice model and parameters of the models are estimated using survey data. A multinomial logit models are developed to design the function of route choice model. As a result, the model which has route length, delay time, the number of turning as parameter is selected based on the significance test. We use existing shortest path algorithm, which can reflect urban transportation network such as u-turn or p-turn, and apply it to the real network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4795-4802
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• 2010

In order to solve the traffic problem in jeju, we must reduce demand for car travel. In addition, demand for passenger travel by public transport policy is needed for conversion. And to improve the quality of public transport services are desperately needed. The purpose of this study, personal characteristics of the trip traveler and the relationship between transportation choice, and personal effectiveness as a factor in travel costs and travel time on the impact of transportation choices will investigate. Restructure its public transportation routes, when to switch to buses to car traffic on the data as a basis for the factors that may be. In addition to improving the quality of public transport services is expected to be able to contribute. To study the performance of the May 2010 survey was conducted. And multinominal logit model were conducted. According to the analysis, People who own homes and families with more than 5 people are likely to use cars. If a prolonged travel time is likely to use buses. However, increasing the cost of travel increases the likelihood that the car is available.

• Journal of Korean Society of Transportation
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• v.28 no.3
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• pp.99-107
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• 2010

Analyzing mode choice among transportation demand estimate procedures is complicated and understanding characteristics of travelers is also difficult. Generally, it is well known that traveler choose mode considering psychometric factors and characteristic besides socio-demographic indicators. Accordingly, many researches has investigated on methodology that can be applied in mode choice to reflect psychometric factor or specific preference. Latent Class Analysis among various studies is recognized as the theoretically potential approach. This study focuses on class segmented using latent class cluster to analyze impact that included psychometric factors and characteristics on mode choice. It also provides evidence that mode choice model for each class and mode choice model not considering latent class are different. This study based on citizen's stated preference and revealed preference on a new transit on the Han river shows that latent class cluster analysis is the potential approach considering latent preference.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.55-67
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• 2002

구간검지체계를 기반으로 한 첨단교통정보제공시스템(Advanced Traveler Information Systems)은 그 기능 수행시 다음의 중요 고려사항을 지닌다. 첫째는 제공 정보의 신뢰성이며, 둘째는 정보수집비용에 관련한 수집자료수의 한계이다. 본 논문에서는 이러한 한계성 극복을 위해 보다 대표성 있는 교통정보 형태의 설정 및 통계적으로 신뢰성 있는 정보산출을 위해 요구되는 적정표본수의 결정에 대한 연구를 수행하였다. 도시고속도로(올림픽대로)와 도시간선도로(천호대로)의 실측 구간통행시간분포 분석결과 단일교차로 구간의 경우 다른 구간들의 단일봉(unimodal)의 정규분포형태와는 다른 두 개의 봉우리를 지닌 분포형태(bimodal)가 나타났다. 따라서 이러한 구간은 기존과는 다른 새로운 교통정보 형태가 필요하며, 본 논문에서는 모든 통과차량들의 평균통행시간으로 정의되는 한 개의 대표치가 아닌 신호주기에 의한 정지여부에 따라 분리되는 주행시간과 지체시간 또는 주행속도와 통행속도 개념의 세분화된 정보형태를 설정하였다. 또한 중심극한정리를 기초로 한 통계적인 표본수 결정식을 이용하여 설정된 신뢰수준 하에서의 정보산출을 위해 요구되는 적정 표본수를 산출하였다. 그 결과, 교통이 혼잡할수록 요구되는 표본수는 적어지는 것으로 나타났다. 우선 적정 표본수 만큼의 표본추출을 하고 제안된 정보산출 방법에 의해 교통정보를 산출한 후 실측치와의 오차를 비교하였다. 그 결과 산출된 교통정보는 신뢰수준 95%와 허용오차 5㎞/h를 만족하였다. 다음으로 구간검지체계를 이용하여 정보를 산출하는 타시스템 교통정보와의 오차율을 비교하였다. 그 결과, 실측치와 본 연구의 산출방법에 의한 교통정보, 로티스교통정보 및 차량번호판 인식시스템의 교통정보와의 비교 결과 제안된 교통정보형태의 타당성을 볼 수 있었다.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.476-488
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• 2016

This study reviewed factors and causes that affect on reliability and accuracy of transportation demand forecasting. In general, the causes of forecasting errors come from variety and irregularity of trip behaviors, data limitation, data aggregation and model simplification. Theoretical understanding about the inevitable errors will be helpful for reasonable decision making for practical transportation policies. The study especially focused on traffic assignment with the KTDB data, and described the factors and causes of errors by classifying six categories such as (1) errors in input data, (2) errors due to spacial aggregation and representation method of network, (3) errors from representing values for variations of traffic patterns, (4) errors from simplification of traffic flow model, and (5) errors from aggregation of route choice behavior.

• Journal of The Korea Institute of Healthcare Architecture
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• v.26 no.3
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• pp.7-16
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• 2020

Purpose: As communicable disease, COVID-19, pandemic strikes over the world, it is critically bewared that air travel possibly be a major pass way to deliver the infectious disease virus. Especially the airplane could be an unique environment to cultivate the virus spreaders. In order to keep the continuous safe airway as well as the industry, related international associations and organizations have been published the guidelines for the prevention and control the infectious disease through the all aspects of aviation. By reviewing the guidelines, focusing on the in-flight infection prevention and control, this study would not only inform a summary of the international guidelines but also provide an essential and general consideration for related research or guideline study. Methods: Guidelines of 5 major countries are reviewed, which has been seriously influenced by COVID-19 : U.S., Canada, E.U., Australia and China. The items of the guidelines are re-categorized as its similarity and structure by applicable cases. Results: The result of this study shows that each guideline seems to share a major structure and issue such as identifying sick traveler, sick passenger care, and cleaning even though that of China has a different since it used to consider the flight conditions based on 3 levels of infection risk. For sick passenger care, the guidelines includes crew safety, service level, sick passenger isolation, and cleaning. Implications: A published guideline as a public manual could be to prevent and control the in-flight infection efficiently and promptly. It also could provide a confidence of knowledge and educate for all users to prepare the in-flight emergency as well.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.81-88
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• 2007

Having been speed development of information delivery using the mobile phone, it is generalization. The Mobile has one of the importance for their information searcher as tool. It is widely recognized that tourism information can be defined as useful and reliable reference which significantly influence the traveler' decision-making. This paper presents pioneer and ongoing study of the method for the pinpionting mobile tourism information system with RTLS, 2D Barcode and mobile phone itself. And, this paper relief that benefit and influence of TCO a view on the business administration points.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.230-236
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• 2007

It is widely recognized that tourism information can be defined as useful and reliable reference which significantly influences the traveler's decision making. As the tourism organizations with online network, along with information system offer an array of information to the public, the passengers more frequently seek and search needed information via internet. However, currently existing tourism contents are mainly designed for suppliers, being viewed by customers perspective, those contents do not reflect the clients inquiries and needs. With the advent of consumer based technology and favorable environment, current tourism-related web sites show some changes from tourism suppliers to User-Created Contents(UCC). The major purpose of this research is to identify the tourism contents provided by both supplier and tourists themselves. Additionally, this paper also indicates research issues for further study.

• Journal of Intelligence and Information Systems
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• v.15 no.4
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• pp.141-158
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• 2009

The requirements of knowledge customization have increased as information resources have become more various and the numbers of the resources are increased. Even if the method for collecting the information has improved like Really Simple Syndication (RSS), information users are still struggling for extracting and customizing the required information through the Web. To reduce the burden, we offer the dynamic knowledge customization framework by using ontology-based CBR. The framework consisting of three phases is comprised of the conversion phase of web information as a machine-accessible case, the extraction phase to find a case appropriate for information users' requirements, and the case customization phase to create knowledge depending on information user's requirements. Newly, the dynamic and intensity-based similarity is adopted to support timely dynamic change of users' requirements. The framework has adopted to create traveler's knowledge to the level users wanted.