• Journal of information and communication convergence engineering
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• v.21 no.3
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• pp.225-232
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• 2023

Owing to advancements in intelligent transportation systems (ITS) and artificial-intelligence technologies, various machine-learning models can be employed to simulate and predict the number of traffic accidents under different weather conditions. Furthermore, we can analyze the relationship between weather and traffic accidents, allowing us to assess whether the current weather conditions are suitable for travel, which can significantly reduce the risk of traffic accidents. In this study, we analyzed 30000 traffic flow data points collected by traffic cameras at nearby intersections in Washington, D.C., USA from October 2012 to May 2017, using Pearson's heat map. We then predicted, analyzed, and compared the performance of the correlation between continuous features by applying several machine-learning algorithms commonly used in ITS, including random forest, decision tree, gradient-boosting regression, and support vector regression. The experimental results indicated that the gradient-boosting regression machine-learning model had the best performance.

• Annual Conference of KIPS
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• 2010.04a
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• pp.198-201
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• 2010

본 논문은 현재 국내 외에서 활발히 연구개발이 진행되고 있는 지능형 교통시스템(ITS: Intelligent Transportation System)의 중요한 역할을 하게 되는 원격감시망의 교통감시 제어시스템을 Internet을 이용하여 개발하고 그에 따라 데이터 송 수신 시 발생할 수 있는 정보 보안의 취약점을 해소하기 위해 대칭암호 알고리즘인 AES(Advanced Encryption Standard) 알고리즘을 적용하였다.

• Annual Conference of KIPS
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• 2022.05a
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• pp.90-93
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• 2022

좁은 ITS(Intelligent Transportation Systems) 대역에서는 채널 혼잡을 피하는 것이 필수적이다. 눈에 띄는 변화가 있을 때만 차량 운동을 보고하는 것은 대역폭 사용을 줄이기 위한 표준화된 접근 방식이다. 그러나 셀룰러 V2X(Vehicle-to-Everything) 통신에서 주기적인 비콘의 빈번한 누락으로 인한 비주기성은 자원 낭비와 자원 스케쥴링의 안정성 문제를 제기한다. 이에 대해 이 논문에서는 자동차의 운동이 물리적 특성에 의해 제약을 받기 때문에 딥러닝 기반 체계로 대부분의 메시지 생성 시간을 정확하게 예측할 수 있다는 것을 보여준다. 제안된 예측 방법은 통상적인 도로주행 시 94.9%의 정확도를 달성한다.

• Annual Conference of KIPS
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• 2011.11a
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• pp.1075-1078
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• 2011

최근 단순한 이동수단의 목적인 자동차에서 IT기술을 접목시킨 스마트 자동차로의 패러다임 변환을 시도하고 있다. 이러한 ITS(Intelligent Transportation System)기반 스마트 자동차에는 기본적으로 차량 통신 네트워크 기술인 V2X(Vehicle-to-Infra/Vehicle/Nomadic)가 통신기술부분으로 이용되고 있다. V2X는 차량과 차량, 인프라, 모바일간의 통신을 도로차량에 적용한 모든 형태의 통신방식을 지칭하는 용어를 의미한다. 이러한 V2X 통신기술을 사용하기 위해서는 각 통신기술마다 주파수가 필요하며 ITU-R에서는 관련 주파수를 권고하고 있다. 하지만 국내 ITS 서비스용으로 할당된 주파수가 ITU-R의 권고사항 및 국외 현황과 상이하여 국내 차량 간 통신 기술 표준화가 보류 상태에 있으며 기술개발이 늦어지고 있는 상황이다. 본 논문에서는 국내외 ITS 주파수 할당 현황을 비교하였고, 해외 ITS 산업 동향 및 기술개발동향에 대해서도 살펴보았다. 본 연구 결과는 국내 ITS 주파수 재분배 혹은 추가 할당에 대한 정책 결정시 참고가 될 수 있을 것이다.

• ETRI Journal
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• v.45 no.4
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• pp.627-635
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• 2023

In vehicular edge computing (VEC) networks, the rapid expansion of intelligent transportation and the corresponding enormous numbers of tasks bring stringent requirements on timely task offloading. However, many tasks typically appear within a short period rather than arriving simultaneously, which makes it difficult to realize effective and efficient resource scheduling. In addition, some key information about tasks could be learned due to the regular data collection and uploading processes of sensors, which may contribute to developing effective offloading strategies. Thus, in this paper, we propose a model that considers the deterministic demand of multiple tasks. It is possible to generate effective resource reservations or early preparation decisions in offloading strategies if some feature information of the deterministic demand can be obtained in advance. We formulate our scenario as a 0-1 programming problem to minimize the average delay of tasks and transform it into a convex form. Finally, we proposed an efficient optimal offloading algorithm that uses the interior point method. Simulation results demonstrate that the proposed algorithm has great advantages in optimizing offloading utility.

• International Journal of Computer Science & Network Security
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• v.24 no.9
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• pp.195-201
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• 2024

Vehicular Ad-hoc Networks (VANETs) became very popular in few years and it has been widely used in research and industry communities. VANET is a collection of wireless vehicle nodes forming a temporary network without using any centralized Road Side Unit (RSU). VANET is a subset of Mobile Adhoc Networks (MANET). It improves the safety of vehicles. It also supports Intelligent Transportation Systems.Routing is the major component of communication protocols in VANETs. Packets are to be routed from the source node to destination node. Because of frequent topology changes and routing overhead, selection of routing protocol in VANET is a great challenge. There are various routing protocols available for VANET. This paper involves study of Temporally Ordered Routing protocol (TORA) and performance metrics are analyzed with the help of NS2 Simulator.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.61-70
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• 2008

The study proposed a new type of bus information, Real-time Bus Crowdedness (RBC) information, to meet various demands of users and improve the convenience level of using public transportation, while existing bus information provided by bus information systems(BIS) were limited to bus operating information such as predicted bus arrival time. To analyze the impacts of providing the proposed RBC information, stated preference(SP) survey was performed and a methodology of disaggregate analysis (e.g., binary logit) was applied to develop passenger choice models. Additionally, passenger choice models incorporating the heterogeneity of different user groups(i.e., by age or trip purposes) were developed to evaluate the different responses on RBC information. The results showed that providing RBC information was significantly related to users' bus choices and the responses of user groups were significantly different, especially the age group of more then 60 was most affected by the RBC information on their bus choices. Also trip purposes were significantly related to users' bus choices, for instance the impacts of providing RBC information was bigger for non-business trips(leisure/meet friend/personal business, shopping, hospital) compared to business trip.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.1
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• pp.1-14
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• 2014

The expansion of the physical road in response to changes in social conditions and policy of the country has reached the limit. In order to alleviate congestion on the existing road to reconsider the effectiveness of this method should be asking. Currently, how to collect traffic information for management of the intersection is limited to point detection systems. Intelligent Transport Systems (ITS) was the traffic information collection system of point detection method such as through video and loop detector in the past. However, intelligent transportation systems of the next generation(C-ITS) has evolved rapidly in real time interval detection system of collecting various systems between the pedestrian, road, and car. Therefore, this study is designed to evaluate the development of an algorithm for queue length based real-time traffic signal control methodology. Four coordinates estimate on time-space diagram using the travel time each individual vehicle collected via the interval detector. Using the coordinate value estimated during the cycle for estimating the velocity of the shock wave the queue is created. Using the queue length is estimated, and determine the signal timing the total queue length is minimized at intersection. Therefore, in this study, it was confirmed that the calculation of the signal timing of the intersection queue is minimized.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.5
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• pp.25-37
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• 2010

This study is aimed at enhancing mobility rights for the transportation underprivileged that has been made light of relatively compared to normal people. In order to do this, we've suggested having ITS (Intelligent Traffic System) built and improving satisfaction through the test operation of its main system. The existing sound signal device for the visually handicapped has one problem with managing it. Because, the people in charge of it had to visit each problematic site directly to maintain and fix some problems every time it was out of order. Moreover, it couldn't provide sustainable services about voice guidance and the visually handicapped had to control it by either confirming the location of buttons that were installed on the pillar of traffic light and then pressing one of them or using a remote controller on their own. In order to improve such inconveniences, we have created a new typed sound signal device for the visually handicapped by applying the cutting-edge wireless technology based on ergonomics considering actual road situations. Such technology enables it report the status of signal device and light to them by using its voice guidance system automatically every time they have access to it. Additionally, we've already introduced it to a couple of test areas and then known the fact that they recognized traffic situation more conveniently and safely compared to the existing sound signal device. That is above average in terms of satisfaction. In addition to that, we've provided LTS (Location Tracking System - Location-based service intended for elementary students) by utilizing the existing wireless infrastructure and founded the fact that about 87% of their parents were satisfied with the service based on LTS.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.532-537
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• 2024

In this study, wear characteristics and microstructure changes due to changes in alloy composition of Ni-Cr-Mo-V and Ni-Cr-Mo low-alloy steels used in brake discs for transportation system such as aircraft and high-speed trains. As a result of the hardness test, the hardness of C-Mo-V steel was the highest at 39.4±0.9HRc, and the hardness of Ni-Cr-Mo steel was the lowest at 32.4±0.6HRc. The friction coefficient tended to decrease as the vertical load increased. At a vertical load of 1 N, the friction coefficient of Ni-Cr-Mo steel was the highest at 0.842, and at a vertical load of 5 N, Mn-Cr-V steel was the highest at 0.696. Ni-Cr-Mo showed the largest wear scar width, depth, and wear amount, with a width of 711 ㎛, a depth of 8.24 ㎛, and a wear amount of 11 mg under a vertical load of 1 N, and a width of 1,017 ㎛, a depth of 19.17 ㎛, and a wear amount of 17 mg under a vertical load of 5 N. As a result of wear mechanism analysis, ploughing, delamination, and adhesion in all specimens, with plastic deformation being more prominently observed in Ni-Cr-Mo.