• Title/Summary/Keyword: rate of route change

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The Influence of Traffic Information based on VMS(Variable Message Sign) on the Selection of Drivers' Route (VMS(Variable Message Sign)를 통한 교통정보 제공이 운전자의 운행경로 전환에 미치는 영향 분석)

  • Jung, Hun Young;Son, Su Ran;Lee, Jeong Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2D
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    • pp.193-201
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    • 2011
  • The provision of traffic information plays an important role in increasing social benefit not only by saving travel time for individuals but also by improving the efficiency of road operation. VMS(Variable Message Sign) helps on-wheel drivers easily understand the road situation, and also provides real-time traffic information to people on the streets. However, it has not been sufficiently studied on how traffic information based on VMS influences on the drivers' selection of route. This study investigated how drivers use VMS traffic information and how they are satisfied with it. Then, the model of drivers' route selection was specified with the types of traffic information and the expected travel time to examine the influence on the selection of drivers' route. The model was estimated and analyzed in three types according to the condition of detour roads, and the rate of route change and the degree of sensitivity was calculated from the estimation. The results of analysis are as follows. the $1^{st}$ type model showed the 10% of route change for the travel time saving of 5minutes, and the 81.6% of route change for the travel time saving of 20minutes. The $2^{nd}$ type led to the range of route change from 14.2% to 92.7% over the 5 through 20 minutes of travel time saving. The $3^{rd}$ model resulted in the 99.1% of route change. The sensitivity of route change showed the highest for the travel time saving of 11 minutes with the $1^{st}$ type model, 9 minutes with the $2^{nd}$ type model, and 5 minutes with the $3^{rd}$ type model respectively.

Location-based Routing Mechanism for Route Discovery (Low-Rate WPAN에서 경로탐색을 위한 위치기반 라우팅 메카니즘)

  • Lee, Jae-Jo;Heo, Joon;Hong, Choong-Seon;Lee, Dae-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.9B
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    • pp.808-817
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    • 2004
  • Many researchers are now working in the Low-Rate WPAN environment. Low-Rate WPAN has as its goal the enhancing computer use by making many sensors available throughout the physical environment, but making them effectively invisible to the user. Low-Rate WPAN environment consists of wireless sensor devices that may move often. Movement of hosts results in a change in routes and the need of some mechanism for determining new routes. This paper suggests an approach to utilize location information to improve performance of a routing mechanism for Low-Rate WPAN Environment. Accordingly, we proved that the proposed mechanism results in a significant reduction in a number of routing messages when comparing with existing mechanisms.

Analysis of Diversion Rate using Expressway Traffic Data(FTMS, TCS): Focusing on Maesong~Balan IC at Seohaean Expressway (고속도로 교통데이터(FTMS, TCS)를 이용한 경로전환율 분석: 서해안고속도로 매송~발안 구간을 중심으로)

  • Ko, Han-Geom;Choi, Yoon-Hyuk;Oh, Young-Tae;Choi, Kee-Choo
    • Journal of Korean Society of Transportation
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    • v.30 no.3
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    • pp.31-41
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    • 2012
  • Due to growing interests in the distribution of traffic volume through information dissemination such as VMS and traffic broadcasting system, the research on the driver's reaction and effect of the traffic report has continued. In this study, we propose a methodology, which estimates the traffic volume of diversion and the consequential diversion rate using FTMS data and TCS data, and the estimation is based on the analysis of the national highway and IC, in which real-time FTMS and TCS data are established. We also calculate the diversion rate of actual targeted sections and analyze the changes in time and spatial diversion rate. In this study, we define a deviation (considering a deviation due to dynamic properties of traffic conditions) found when the outflow traffic volume is temporarily higher than the average outflow traffic volume on a relevant time slot after providing traffic information. The diverting volume is considered to be caused by the traffic information, and the study determines the ratio of traffic volume on highways to that of route diversion as the diversion rate. The analysis on changes in the diversion rate in accordance with the time flow, the initial change in the diversion rate on upstream IC that first acquires the report on the traffic congestion is significant. After that, the change in the diversion rate on upstream IC affects the route diversion on downstream IC with spatial and time flow, and this again leads the change in upstream IC. Thereby, we confirmed that there is a feedback-control circulation system in the route diversion.

Intelligent Optimal Route Planning Based on Context Awareness (상황인식 기반 지능형 최적 경로계획)

  • Lee, Hyun-Jung;Chang, Yong-Sik
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.117-137
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    • 2009
  • Recently, intelligent traffic information systems have enabled people to forecast traffic conditions before hitting the road. These convenient systems operate on the basis of data reflecting current road and traffic conditions as well as distance-based data between locations. Thanks to the rapid development of ubiquitous computing, tremendous context data have become readily available making vehicle route planning easier than ever. Previous research in relation to optimization of vehicle route planning merely focused on finding the optimal distance between locations. Contexts reflecting the road and traffic conditions were then not seriously treated as a way to resolve the optimal routing problems based on distance-based route planning, because this kind of information does not have much significant impact on traffic routing until a a complex traffic situation arises. Further, it was also not easy to take into full account the traffic contexts for resolving optimal routing problems because predicting the dynamic traffic situations was regarded a daunting task. However, with rapid increase in traffic complexity the importance of developing contexts reflecting data related to moving costs has emerged. Hence, this research proposes a framework designed to resolve an optimal route planning problem by taking full account of additional moving cost such as road traffic cost and weather cost, among others. Recent technological development particularly in the ubiquitous computing environment has facilitated the collection of such data. This framework is based on the contexts of time, traffic, and environment, which addresses the following issues. First, we clarify and classify the diverse contexts that affect a vehicle's velocity and estimates the optimization of moving cost based on dynamic programming that accounts for the context cost according to the variance of contexts. Second, the velocity reduction rate is applied to find the optimal route (shortest path) using the context data on the current traffic condition. The velocity reduction rate infers to the degree of possible velocity including moving vehicles' considerable road and traffic contexts, indicating the statistical or experimental data. Knowledge generated in this papercan be referenced by several organizations which deal with road and traffic data. Third, in experimentation, we evaluate the effectiveness of the proposed context-based optimal route (shortest path) between locations by comparing it to the previously used distance-based shortest path. A vehicles' optimal route might change due to its diverse velocity caused by unexpected but potential dynamic situations depending on the road condition. This study includes such context variables as 'road congestion', 'work', 'accident', and 'weather' which can alter the traffic condition. The contexts can affect moving vehicle's velocity on the road. Since these context variables except for 'weather' are related to road conditions, relevant data were provided by the Korea Expressway Corporation. The 'weather'-related data were attained from the Korea Meteorological Administration. The aware contexts are classified contexts causing reduction of vehicles' velocity which determines the velocity reduction rate. To find the optimal route (shortest path), we introduced the velocity reduction rate in the context for calculating a vehicle's velocity reflecting composite contexts when one event synchronizes with another. We then proposed a context-based optimal route (shortest path) algorithm based on the dynamic programming. The algorithm is composed of three steps. In the first initialization step, departure and destination locations are given, and the path step is initialized as 0. In the second step, moving costs including composite contexts into account between locations on path are estimated using the velocity reduction rate by context as increasing path steps. In the third step, the optimal route (shortest path) is retrieved through back-tracking. In the provided research model, we designed a framework to account for context awareness, moving cost estimation (taking both composite and single contexts into account), and optimal route (shortest path) algorithm (based on dynamic programming). Through illustrative experimentation using the Wilcoxon signed rank test, we proved that context-based route planning is much more effective than distance-based route planning., In addition, we found that the optimal solution (shortest paths) through the distance-based route planning might not be optimized in real situation because road condition is very dynamic and unpredictable while affecting most vehicles' moving costs. For further study, while more information is needed for a more accurate estimation of moving vehicles' costs, this study still stands viable in the applications to reduce moving costs by effective route planning. For instance, it could be applied to deliverers' decision making to enhance their decision satisfaction when they meet unpredictable dynamic situations in moving vehicles on the road. Overall, we conclude that taking into account the contexts as a part of costs is a meaningful and sensible approach to in resolving the optimal route problem.

Estimating an Incheon New Ports' allotment rate for metropolitan cargo using Logit Model - Focusing on a trans pacific route - (Logit모형을 이용한 인천 신항의 수도권 화물 분담률 추정에 관한 연구 - 미주항로를 중심으로 -)

  • Lee, Yun Chan;Lee, Taehwee;Yeo, Gitae
    • Journal of Korea Port Economic Association
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    • v.30 no.1
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    • pp.143-157
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    • 2014
  • Most metropolitan shippers (MS) have used trans pacific route (TPR) or Asia-Europe route (AEP) through Busan port (BP). If Incheon new port (INP) sets up the deep water-depths under -16m, however, there might be a change in MS's port choice behavior (PCB). In this respect, the aim of this paper is to estimate an INP's allotment rate for metropolitan cargo using Logit Model (LM) considering changing global shipping and port environment. This paper reviews previous studies related to shippers' PCB then sets up the utility function (UF) including the dummied dependent variable which is comprised of BP and INP, and some independent variables such as the frequency of liner shipping route (TPR), inland transportation fare, and the rate of container terminal service. As a result of LM analysis, BP has 0.6618 and INP has 0,3382.

Analysis of Effect of the Ship's Route Exchange through the Ship Handling Simulation (선박조종 시뮬레이션을 통한 선박 경로 교환의 효과 분석)

  • Paek, Yun-Ji;Jung, Chang-Hyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.1
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    • pp.10-17
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    • 2018
  • To prepare the integrated safety management system 'e-navigation', research is being conducted on the route exchange for sharing intended routes between ship and ship, and between ship and land. But they don't have enough specific grounds for the effects of route exchange and the necessity of its introduction and focus on technical aspects like the implementation of route exchange. This study tried to quantitatively analyze the effects of route exchange on sailing safety with the use of ship handling simulation, integrate simulation performers' subjective evaluations, and investigate the effects of route exchange. The ship-to-ship route exchange resulted in the initial collision avoidance action time was 3.43 minutes faster, the collision avoidance direction change rate was 60 %, the proximity to target A was 31 %, and Mean Rudder Angle Index decreased by 57 %. In addition, 95 % of the survey respondents had an effect on the decision making of collision avoidance, 85 % had a positive impact on safety navigation, 90 % had an accident prevention effect, 70 % reduced the psychological burden of officers, and 70 % should be introduced in practice.

Advanced AODV Routing Performance Evaluation in Vehicular Ad Hoc Networks (VANET에서 Advanced AODV 라우팅 성능평가)

  • Lee, Jung-Jae;Lee, Jung-Jai
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.6
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    • pp.1011-1016
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    • 2020
  • Rapid change in network topology in high-speed VANET(: Vehicular Ad Hoc Network) is an important task for routing protocol design. Selecting the next hop relay node that affects the performance of the routing protocol is a difficult process. The disadvantages of AODV(: Ad Hoc On-Demand Distance Vector) related to VANET are end-to-end delay and packet loss. This paper proposes the AAODV (Advanced AODV) technique to reduce the number of RREQ (: Route Request) and RREP (: Route Reply) messages by modifying the AODV routing protocol and adding direction parameters and 2-step filtering. It can be seen that the proposed AAODV reduces packet loss and minimizes the effect of direction parameters, thereby increasing packet delivery rate and reducing end-to-end delay.

Improving TCP-Vegas Performance over Mobile Ad-hoc Networks (이동 애드혹 네트워크에서의 TCP-Vegas 성능향상 기법)

  • Bae Han-Seok;Song Jeom-Ki;Kim Dong-Kyun;Park Jung-Soo;Kim Hyoung-Jun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.3A
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    • pp.221-231
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    • 2006
  • TCP is needed as a transport protocol to provide reliable end-to-end message delivery for MANETs in order to achieve a smooth integration with the fixed Internet. Particularly, TCP has its variants, namely TCP-Reno and TCP-Vegas. However, there has been no research work on extensive performance comparison of TCP-Reno and TCP-Vegas over AODV and OLSR. This paper is the first trial to perform the research by using ns-2 simulator. Through the extensive simulations, we found that which to select among routing protocols is more important than which to select among TCP variants, because the performance difference between TCP-Reno and TCP-Vegas over uy selected routing protocol is not so much outstanding. Particularly, TCP-Vegas relies on an accurate BaseRTT estimation in order to decide the sending rate of a TCP Sender. However, it cannot be directly applied to MANET because a route change makes the Base an used over a Previous Path obsolete. Therefore, we propose a technique for improving the performance of TCP-Vegas by considering the route change, and show the performance improvement through simulation study.

An Experimental Study on Exhaust Gas Change of a Heavy-Duty Diesel Engine by EGR (대형디젤기관의 EGR에 의한 배기가스변화에 관한 실험적 연구)

  • 오용석;문병철;한영출
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.6
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    • pp.59-64
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    • 2002
  • The effects of EGR on emissions were investigated by using a six-cylinder, 8 litre, turbo-charged, heavy-duty diesel engine with a low pressure route EGR system. The experiments were performed at various engine loads while the EGR rates were set from 0% to 30%. Hot and cooled EGR are achieved without cooling and with cooling respectively. To verify the possibility of EGR technology for the applications, test were performed with steady state test cycle. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke and PM emissions. Increasing the EGR rate leads to deteriorating specific fuel consumption and power at lower speed and higher load. Also, the reduction rates of NOx emissions for hot and cooled EGR are similar.

AODV Routing Algorithm Considering Successful Transmission Rate for QoS Support (전송성공률을 고려한 QoS보장 AODV 알고리즘)

  • Cho, Byeong Seok;Lee, Juhyeon;Park, Hyung-Kun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.10a
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    • pp.741-742
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    • 2013
  • AODV algorithm is one of the widely used algorithm for wireless ad-hoc environment In AODV, the destination node selects the route with smallest hop count. Since AODV only consider hop count, the selected route could have low capacity link, and degrade QoS. In this paper, we propose a modified AODV algorithm that consider successful transmission rate of each link. Advantage of proposed algorithm is that AODV can support QoS without significant change of the algorithm using modified hop count.

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