• Title/Summary/Keyword: U-traffic

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GNSS Center of Excellence for Safety Critical Applications, Simulation, Test & Certifications - GAUSS

  • Evers, H.
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.153-155
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    • 2006
  • A major advantage of the area in and around Braunschweig is its concentration of major research institutes and small to large enterprises dealing with different modes of transportation. For many years, aviation has been a particular focus. The research institutes have aircraft and helicopters equipped especially for research projects, as well as other laboratory equipment, allowing simulation and testing of air traffic application both virtually and on real aircraft. In addition, with the Luftfahrtbundesamt (equivalent organization to FAA) and the Bundesstelle $f{\"{u}}r$ Flugunfalluntersuchung (equivalent to NTSB) both located at the Research Airport, it enables direct contact with two key air-traffic safety authorities. The institutes of DLR and the Technical University of Braunschweig are very active in rail transportation applications. Cooperation with the market leader in rail automation - Siemens Rail Automation, also located in Braunschweig - and with other companies in the Braunschweig region means that safety-critical road applications and mobility research is available due to the activities of a number of institutes. Cooperation with Volkswagen (VW) and other companies in the region ensure access to the market leaders' know-how in this sector. Current European activities within framework of the Galileo project offer particularly good opportunities for the Research Airport to leverage its expertise and position itself internationally as a specialist in safety-critical transport applications - the centre is an initiative of Niedersachsen and the Ministry of Economic Affairs, Labour and Transport Location and navigation plays a central role in all modes of transport - air, road and rail. The market is being revolutionized by the increasing integration of GNSS. The realization of the Galileo system will provide additional opportunities for the Research Airport: Galileo as a civil operated system offers service guarantees especially in the area of safety-critical applications in transportation. Notably standards, processes and authorizations related to the certification of safety-critical applications in the areas of air, road and rail transportation are still to be determined. GAUSS, located at the Research Airport Braunschweig, as an European centre of excellence for simulation, testing and certification of safety-critical applications can offer its expertise to validate the services guaranteed by the Galileo concessionaire.

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Performance analysis of the Resource Reservation Schemes using Mobile Cluster based H-MRSVP in Wireless Mobile Networks (무선 이동망에서 이동 클러스터 기반의 H-MRVP를 이용한 자원관리 기법의 성능 분석)

  • Ma, Gyeong-Min;Won, Jeong-Jae;Lee, Hyeong-U;Jo, Chung-Ho
    • The KIPS Transactions:PartC
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    • v.9C no.2
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    • pp.283-292
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    • 2002
  • This paper develops a scheme of resource management for guaranteeing QoS of realtime traffic in wireless mobile internet environments Mobile terminal has significant impact on the QoS originating mobility provided to a real-time application. The currently proposed MRSVP is not clear the boundary of resource reservation tregion and also can give rise to signal overhead to maintain sessions. To solve above problem, we propose the new reservation protocol, mobile cluster based H-MRSVP to combine MRSVP with moving cluster concept. In this paper, we analytically design our model for guaranteeing the QoS of realtime traffic and compare the three schemes: guard channel allocation schemes, DCA and our model. The performance measures are the probabilities of new call blocking, handoff dropping, resource utilization and service completion versus the system offered Erlang load. Consequently, Simulation indicate our model is more flexible than DCA in a view pint of channel utilization and gains the advantage over guard channel scheme with respects to the mobility.

Link Travel Time Estimation Using Uncompleted Link-passing GPS Probe Data in Congested Traffic Condition (혼잡상황에서 링크미통과 GPS 프로브데이터를 활용한 링크통행시간 추정기법 개발)

  • Sim, Sang-U;Choe, Gi-Ju
    • Journal of Korean Society of Transportation
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    • v.24 no.5 s.91
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    • pp.7-18
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    • 2006
  • Data for travel information Provision are regularly aggregated to Provide travel time information in a reliable and convenient manner and to manage traffic data and information efficiently. In most of practices in Korea, the GPS based travel time data are mainly aggregated every 5 minutes As a result, some probes can't pass by a link within aggregation interval and thereby create uncompleted link passing data. But these data are mostly generated during the congested times and therefore a method that uses such uncompleted link passing data are required. This study estimated queue dissipation length, green time and cycle that use GPS spot speed and developed a link travel time estimation method using such uncompleted link passing data. It also presents method and the overall process of using such data to estimate link travel time in a more accurate manner. As a result, MAPE 1.98% and MAE 4.75 sec of link travel time accuracy improvement has been reported, which is not much different from the real link travel time. The method Proposed here would be an alternative to increase the amount of GPS probe data, especially in congested urban arterial case.

Economic Feasibility Analysis for Introducing Integrated Management System for Supporting Underground Construction (지하구조물건설 현장지원 통합관리시스템 도입을 위한 경제적 타당성 분석)

  • Baek, Hyeon Gi;Jang, Yong Gu;Seo, Jong Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.5D
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    • pp.513-522
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    • 2010
  • Underground construction for traffic networks, complexes, and storage facilities has risen as an effective land use plan for dealing with emerging problems such as overcrowded urban cities and traffic jams. This paper performed an economic feasibility analysis of the development of the integrated field management system which provides field workers and managers with 3D-based location tracking and clear communication during underground construction works. To conduct the analysis, processes and problems of field management for underground construction were analyzed and deduction in accidents and field management costs and productivity improvement were estimated as expected benefits. Based on computed benefits and costs, an economic analysis was conducted using Benefit/Cost ratio(B/C), Net Present Value(NPV), and Internal Rate of Return(IRR) and then sensitivity analysis was performed to cope with the uncertainty of assumed variables.

Relationship between V/C and Accident Rate for Freeway Facility Sections (focused on Shingal-Ansan Freeway) (고속도로 시설물 구간의 교통혼잡도와 사고율의 관계 분석 (신갈-안산 고속도로를 중심으로))

  • Oh, Cheol;Chang, Jae-Nam;Chang, Myeong-Sun
    • Journal of Korean Society of Transportation
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    • v.17 no.2
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    • pp.21-27
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    • 1999
  • The objective of this study is to clarify the relationship between accident rate and V/C for freeway facility. The relationship can be used as a basic reference to predict and prevent traffic accident. The traffic volume and the number of accidents from 1992 to 1997 on Shingal-Ansan Freeway were analyzed in this study to clarify the relationship. Hourly accident rate and V/C were calculated for each facility sections : basic freeway section, tunnel section and toll gate section. The accident rate models consisting of an independent variable of V/C were established by repression analysis and compared with each other. The relationship between accident rates and V/C ratios represented U-shaped pattern for all sections. The result of this study indicates that accident rates are highest in the low hourly V/C range, decrease with increasing V/C ratio, and then increase as the V/C ratio increases. The accident rate of toll gate section is in general higher than that of other sections. Although the accident rate of tunnel section is higher than that of basic freeway section when V/C is above 0.67, there is no significant difference of accident rate between basic freeway and tunnel section when V/C is between 0.5 and 0.8. Basic freeway tunnel and toll gate section have the minimum accident rate when V/C is 0.78, 0.75 and 0.57 respectively.

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Finding the First K Shortest Loopless Paths in a Transportation Network (교통망에 적합한 K 비루프 경로 탐색 알고리즘)

  • Shin, Seong-Il
    • Journal of Korean Society of Transportation
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    • v.22 no.6
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    • pp.121-131
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    • 2004
  • The K-shortest path algorithms are largely classified into two groups: oneis for finding loopless path (simple path), another loop paths. In terms of cimputational complexities, in general the loop-paths-finding ones are considered more efficient and easier to be handled than the loopless-paths-finding. The entire path deletion methods have been known as the best efficient algorithms among the proposed K-shortest path algorithms. These algorithms exploit the K-th network transformation to prevent the same path, which was already selected as the (K-1)th path, from being redetected. Nevertheless, these algorithms have a critical limitationto be applied in the practical traffic networks because the loops, in which the same modes and links can be unlimitedly repeated, are not preventable. This research develops a way to be able to selectively control loop-paths by applying link-label. This research takes an advantage of the link-based shortest path algorithms that since the algorithms can take care of two links simultaneouslyin the searching process, the generation of loops can be controlled in the concatenation process of the searched link and the preceded link. In concatenation of two links, since the precede link can be treated a sub-shortest to this link from the origination, whether both the node and the link of the searched link were already existed or not can be evaluated. Terefore, both the node-loopless path, in which the same node is not appeared, and the link-loopless, in which the same link is not appeared, can be separately controlled. Especially, the concept of the link-loopless path is expended to take into consideration reasonable route choice behaviors such as U-Turn, P-Turn, and Turn-Penalty, which are frequently witnessed in urban traffic network with intersections. The applicability of the proposed method is verified through case studies.

A Study on the Road Safety Analysis Model: Focused on National Highway Areas in Cheonbuk Province (도로 안전성 분석 모형에 관한 연구: 전라북도 국도 권역을 중심으로)

  • Lim, Joonbeom;Kim, Joon-Ki;Lee, Soobeom;Kim, Hyunjin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.2
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    • pp.583-595
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    • 2014
  • Currently, Korean transportation policies are aiming for increase of safety and environment-friendly and efficient operation, by avoiding construction and expansion of roads, and upgrading road alignments and facilities. This is revealed by that there have been 22 road expansion projects (30%) and 50 road improvement projects (70%) under the 3rd Five-Year Plan for National Highways ('11~'15), while there were 53 road expansion projects (71%) and 22 road improvement projects (29%) under the 2nd Five-Year Plan for National Highways. For more effective road improvement projects, there is a need of choosing projects after an objective and scientific safety assessment of each road, and assessing safety improvement depending on projects. This study is intended to develop a model for this road safety analysis and assessment. The major objective of this study is creating a road safety analysis and assessment model appropriate for Korean society, based on the HSM (Highway Safety Manual) of the U.S. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. In order to build up data for model development, the sections thought to have identical geometrical structure factors in 5 lines, Cheonbuk province, were divided as homogeneous sections, and representative values of geometric structures, facilities, traffic volume, climate conditions and land usage were collected from the 1,452 sections divided. The collected data was processed correlation analysis of each road element was implemented to see which factor had a big effect on traffic accidents. On the basis of these results, then, an accident model was established as a negative binomial regression model.Using the developed model, an Crash Modification Factor (CMF) which determines accident frequency changes depending on safety performance function (SPF) predicting the number of accident occurrence through traffic volume and road section expansion, road geometric structure and traffic properties, was extracted.

A Study on Tram Traffic Accidents Characteristics and Safety Measures (트램 교통사고 특성 및 안전대책에 관한 연구)

  • Lee, Sooil;Myung, Myohee;Kim, Taeho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.4
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    • pp.505-512
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    • 2019
  • This study is a basic study to prepare safety measures for the tram that is being introduced into Korea by reviewing accident analysis and accident compensation system of the tram. Analysis of accident characteristics of the tram was analyzed based on overseas data. Five years after the inauguration of the tram, accidents were halved and stabilized. Deaths accounted for 0.5 % of all casualties, most accidents were minor. Accidents with other mean transportation were high 84.1 %, among them accidents with passenger cars was found to be highest. The frequent points of accidents were analyzed as intersections and tram stop, and measures for pedestrian accidents were found to be important. Those are proposed safety measures through analyzing tram accident characteristics: Monitoring accidents which occur within five years of its inauguration, developing accident database input system, installation of fences for preventing people from jaywalking, operating traffic signal for preventing people from jaywalking through connection of pedestrian signals and tram signals, clamping down on illegal U-turn cars and jaywalking pedestrian, Also, those are proposed accident treatment measures based on general driver receptively and overseas data: property damage liability coverage (PI) of car insurance, comparative negligence when the accident occurs between car and tram.

A Study on the Ripple Effect Economy of Busan Ubiquitous-Safety Realization on Using an Input-Output Model (I-O모형을 이용한 부산 U-방재 실현의 경제적 파급 효과 분석에 관한 연구)

  • Ryu, Tae-Chang;Kim, Tae-Min;Kim, Gyeong-Su
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.6
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    • pp.93-100
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    • 2008
  • Dense of population construction and high density of skyscraper, and geological characteristics caused natural disasters(e.g. typhoon, tsunami, flood, storm, earthquake, etc.) and manmade disasters(e.g. fire, collapse, explosion, traffic accident, etc.). the extent and scale of the disaster are getting larger. To cope with such problems, Busan City has established the basic plan to secure the life and property of the citizens through model strategy and design of Ubiquitous-Safety Busan. This study quantitatively analyzed the ripple effect on local economy through the fulfillment of Ubiquitous-Safety. The production inducing effect of 250 billion won directly and indirectly can be estimated due to the realization of Ubiquitous-Safety. The value added effect of 115 billion won can be estimated. the employment effect of 5,580 persons can be generated with income effect of 51 billion won.

The Economic Impact of the Open Skies Agreement Between Singapore and U.S.A. (미국과 싱가포르의 항공자유화 협정으로 인한 경제적 영향에 관한 연구)

  • Hong, S.K.;Lee, S.C.;Lee, K.S.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.10 no.1
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    • pp.69-82
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    • 2002
  • Recently, it appears that the major change in open skies agreement established the bilateral agreement and sub-regional multi-lateral agreement system with U.S.A. as the central figure. Specifically sub-regional multi-lateral air transportation cooperation is based on the bilateral agreement systems among the like minded countries. To develop the air transportation industry, Each country tries to come true free air transportation in bloc and deregulation in terms of market approach and traffic right. The purpose of this study is to look into the background of sub-regional air transportation cooperation and to expect the economic impact of the open skies agreement. We selected the Singapore in Asia-Pacific region as the subject of investigation. Even though Singapore is a small country in Asia-Pacific region. They have global competition power which is airport field as well as to airlines and tourism industry. Under this condition, we analyzed the economic impact of the open skies policy through the Input/Output analysis.

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