• Journal of the Korean Society for Railway
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• v.16 no.2
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• pp.110-116
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• 2013

Track irregularities is one of the key factors influencing the running behavior of trains. In order to ensure safety and ride comfort of train, the criteria for track irregularities should be adequately established regarding vehicle velocity, vehicle characteristics, characteristics of the track recording car, and measurement interval. Also, track maintenance should be carried out thoroughly according to the criteria for managing track irregularities. Numerical analysis was conducted to investigate the influence of track alignment on the running behavior of Korean high speed train(KTX). Various wavelengths and amplitudes of lateral alignment were considered as parameters for this study using the Vampire program, a vehicle dynamics modeling package in railway environment. Derailment, lateral load, bogie acceleration and body acceleration of numerical analysis results due to alignment were investigated. Finally, the influence of the alignment on safety and ride comfort for the KTX was evaluated. This study indicates that alignment irregularities have significant impacts on running safety, and that the criteria used to manage alignment irregularities should be restrictive to ensure the running safety of the KTX.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.767-774
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• 2008

This study has been developed the way that evaluates the road safety using the speed of individual vehicles at curve sections in 2-lane rural highways. For this study, we developed variation of operational speed for the individual vehicle using the speed of vehicles in 96points of selected roads. Drawing out of variation of operational speed for the individual vehicle, estimation models for speed variation of individual vehicles considering horizontal alignments and vertical alignments of the roads have been developed. These models presents the way to evaluate road safety out of the operational speed and acceleration of individual vehicles. Considering safety and based on the results of these study above, some regular spots are ranked by "good", "fair", "bad". The results that this study showed in this paper could be useful to derive some particular spots that needs to be improve in terms of safety.

• Proceedings of the Safety Management and Science Conference
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• 2000.11a
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• pp.91-94
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• 2000

본 연구에서는 차량용량이 같지 않은 복수의 다른 종류의 차량을 고려하여, 차량이 이동하면서 배달과 수거를 동시에 수행하고 수거지점으로부터 화물을 수거하여 차고지로 운송하는 귀로 화물(Backhauls)을 갖는 PDP(Pickup and Delivery Problem)문제를 그 연구 대상으로 한다. 동시에 차량을 통해 이동되는 품목이 단일 품목이 아니고, 배달 및 수거시간제약조건을 갖는 다품목 시간제약 수송차량 배차문제를 Time-space network를 이용하여 정수선형계획문제로 정식화한다. 이를 최적화 S/W LINGO를 이용하여 위의 모든 제약조건을 만족하면서 운용되는 차량수와 차량의 이동경로를 최소화하는 해를 구하고, 분석한 내용을 보여주고자 한다. 덧붙여 위 문제의 입·출력자료를 데이터베이스화하여 지리정보시스템(Geographic Information System : GIS)과 통합한 차량운행경로결정 지원시스템을 구축하기 위한 방법을 제시하고자 한다.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.180-189
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• 2013

The SMART Highway project combines road construction with advanced technology and vehicle telecommunications. Its expected outcome is a world-leading intelligent road that is green, fast, and comfortable. A vehicular ad-hoc network(VANET) is the core technology of the SMART Highway, whose transport operation is based on road vehicles. The VANET is a next-generation networking technology that enables wireless communication between vehicles or between vehicles and a road side unit(RSU). In the VANET system, a vehicle accident is likely to cause a serious disaster. Therefore, some information on safety is essential to serve as the key exchange protocol for communication between vehicles. However, the key exchange scheme of the general network proposed for a fast-moving communication environment is unsuitable for vehicles. In this paper, communication between multiple vehicles more efficient and secure key exchange at the vehicle certification by signcryption is proposed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.151-158
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• 2019

Wireless communication technology (WAVE) for vehicles, which is the core technology behind the next-generation intelligent transport system (C-ITS), is used to deliver information about vehicles to prevent traffic accidents and traffic situations that may arise between vehicles and infrastructure. Similar traffic issues often arise in marine scenarios. Currently, AIS is being used as a means of transmitting information such as the status of relative vessels, but research is being carried out to solve problems with AIS such as overloading by applying wireless communication technology for vehicles to the sea. In this study, a collision warning system suitable for small-sized vessels was developed based on the marine application of WAVE for vehicles verified through prior research, and the adequacy of this collision warning system was reviewed through a practical test. It is expected that this system will contribute greatly to future e-Navigation applications or self-driving ships as well as to preventing marine accidents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7C
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• pp.576-583
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• 2012

Security over VANET among vehicles and between vehicles and infrastructures has been studied. Through the research, ensuring the message authentication and confidentiality was possible. However, authentication on drivers and vehicles were not actively covered. Once, malicious user using illegal vehicle joins VANET and then generates mistaken information, other drivers' safety will be driven to crisis. For this reason, in the paper, we present a novel authentication method between drivers and vehicles and then only right vehicles and users can participate in VANET. As a result of this, drivers can enjoy their safe and comfortable trip.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.1-14
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• 2012

Traffic management centers (TMC) collect real-time traffic data from the field and have powerful databases for analysing, recording, and archiving the data. Recent advanced sensor and communication technologies have been widely applied to intelligent transportation systems (ITS). Regarding sensors, various in-vehicle sensors, in addition to global positioning system (GPS) receiver, are capable of providing high resolution data representing vehicle maneuverings. Regarding communication technologies, advanced wireless communication technologies including vehicle-to-vehicle (V2V) and vehicle-to-vehicle infrastructure (V2I), which are generally referred to as V2X, have been widely used for traffic information and operations (references). The V2X environment considers the transportation system as a network in which each element, such as the vehicles, infrastructure, and drivers, communicates and reacts systematically to acquire information without any time and/or place restrictions. This study is motivated by needs of exploiting aforementioned cutting-edge technologies for developing smarter transportation services. The proposed system has been implemented in the field and discussed in this study. The proposed system is expected to be used effectively to support the development of various traffic information control strategies for the purpose of enhancing traffic safety on highways.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.5D
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• pp.443-451
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• 2010

This paper proposes the methodology about advisory safety speed based on real-time vehicular data collected from highway. The proposed model is useful information to drivers by appling seamless wireless communication and being collected from ECU(Engine Control Unit) equipment in every vehicle. Furthermore, this model also permits the use of realtime sensing data like as adverse weather and road-surface data. Here, the advisory safety speed is defined "the safety speed for drivers considering the time-dependent traffic condition and road-surface state parameter at uniform section", and the advisory safety speed model is developed by considering the parameters: inter-vehicles safe stopping distance, statistical vehicle speed, and real-time road-surface data. This model is evaluated by using the simulation technique for exploring the relationships between advisory safety speed and the dependent parameters like as traffic parameters(smooth condition and traffic jam), incident parameters(no-accident and accident) and road-surface parameters(dry, wet, snow). A simulation's results based on 12 scenarios show significant relationships and trends between 3 parameters and advisory safety speed. This model suggests that the advisory safety speed has more higher than average travel speed and is changeable by changing real-time incident states and road-surface states. The purpose of the research is to prove the new safety related services which are applicable in SMART Highway as traffic and IT convergence technology.

• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.95-102
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• 2006

This study develops a methodology on how to assess the traffic safety benefit of advanced vehicular technology for Protecting pedestrian in pedestrian-vehicle collision. Safety benefit is defined here as the reduction of Pedestrian fatality by employing advanced vehicular technology. As an application of the proposed methodology the safety benefit of active hood lift system (AHLS) is assessed. Both actual accident data analysis and simulation experiment are conducted to establish statistical models that are used for estimating the reduction of pedestrian fatality It is believed that the developed methodology and outcomes would be greatly useful in developing various advanced vehicular technologies and establishing more effective traffic safety policies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.794-797
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• 2015

As the interest in VANET is increased, a study on the beacon message transmission between vehicles is actively being made. IEEE 802.11p/1609.4 standard is based on a multichannel system consisting of multiple service channels (SCH) and a control channel (CCH). Multiple SCHs are defined for nonsafety data transfer, while the CCH is used to broadcast safety messages called beacons and control messages (i.e., service advertisement messages). However, most messages broadcast in the only one CCH belong to safety application that must be contested in dense vehicular network. This paper suggests safety message transfer algorithm in dense vehicular congestion. The proposed algorithm is that the priority of safety messages is decided by decision tree and messages are stored in proper queues according to their priorities. Then, safety messages with higher priorities are sent in turn by CCH in the assigned time. The proposed algorithm decreases the beacon transmission delay and increase on the probability of a successful beacon reception in an IEEE 802.11p/1609.4-based network.