• International Journal of Highway Engineering
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• v.13 no.3
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• pp.83-91
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• 2011

The objective of VMS(Variable Message Sign) is to provide the traffic information downstream to drivers upstream so that they can choose their routes or expect the travel time to arrive the destination. Because there is not enough time and space to show the message, VMS message should be selected carefully. However, the message of VMS has been simply selected among the pre-designed message sets based on the priority rule of events. If the traffic demand between origin and destination is identified along the freeway, message can be selected to provide the information of a route that more drivers will use. In this study, a time sliced OD(Origin/Destination) estimation method will be developed using the detector information of the on-ramp, exit ramp, and the main lanes. And the strategy of a priority rule of message was planned.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.51-62
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• 2009

Variable message signs (VMS) are a useful tool for providing real-time traffic information to drivers. In particular, effective warning information provision leading to safer driving would be an important countermeasure to prevent traffic accidents. The purpose of this study was to identify users' preferences for traffic safety warning information formats. A variety of warning information scenarios using text and pictograms were devised and investigated for the purpose of selecting more effective methods to provide warning information. A portable variable message sign (PVMS) was used to evaluate users' preferences. The results of this study can be used for designing better warning information for the enhancement of traffic safety.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.4
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• pp.25-35
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• 2008

Variable Message Sign(VMS) is one of the subsystem of Intelligent Transportation Systems (ITS), which is useful for providing real-time information on weather, traffic and highway conditions. However, there are various situations such as incidents/accidents, constructions, special events, etc., which would be occurred on segments, it is unable to control traffic with only the VMS. Thus, it is essential to use of PVMS(Portable Variable Message Signs), which can move to the location needed traffic control and provide more active traffic information than VMS. This study developed a legibility distance model for PVMS messages using in-vehicle Differential Global Positioning Data(DGPS). Traffic conditions, drivers' characteristics, weather conditions and characteristics of PVMS message were investigated for establishing the legibility model based on multiple linear regression analysis. The factors such as height of PVMS characters, spot speed, age, gender and day and night were identified as dominants affecting the variation of legibility distances. It is expected that the proposed model would play a significant role in designing PVMS messages for providing more effective real-time traffic information.

• The Transactions of the Korea Information Processing Society
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• v.4 no.7
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• pp.1797-1803
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• 1997

Message handling function of the SS7(Signaling System N0.7) provides signaling traffic routing capabilities to transfer the signaling traffic to the destination nodes in the signaling network. This message handling function should be handled without any transfer delay for real time processing of large amount of signaling traffic for data communication service, and visual information service. In this paper, we suggest two routing algorithms working on the distributed message handling processors which were specially designed for message handling function. The one is an internal distributing algorithm for equal distribution of signaling traffic among the distributed message handling processors and the other is a distributing algorithm for distribution of signaling traffic in the multiple signaling routes. Both of algorithms are using signaling link selection codes labled in each signaling messages. It is shown that the suggested algorithms are very efficient for routing signaling traffic at the fault condition of signaling routes and the restoration of unavailable signaling routes.

• Journal of information and communication convergence engineering
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• v.8 no.6
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• pp.623-629
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• 2010

A geographical routing protocol is typically utilized for a route selection of VANET. Even if it is conceptually well adapted into VANET, message delivery tends to be unreliable with frequent network partitions, which mainly come from the inherent characteristics such as high mobility and irregular traffic density. In this paper, we deal with a method to enable reliable message delivery with reflecting the traffic density on routing decision. By concatenating the message delivery cost of each of inbetween junction section, $1^{st}$ and $2^{nd}$ shortest paths are initially determined. When it is not possible to deliver the message on a junction on the 1st path, we utilize two novel ideas, that is, letting the message stay on the junction to find out a new relay node, and putting a replicated copy to reach via a detour path. By using the NS-2 network simulator, our method has been examined in terms of message delivery rate and delay. It shows that our method is much efficient than the other method in the low density environment, while it brings similar results in the high density environment.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.386-391
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• 2016

A traffic message delivery system using visible light communication(VLC) link has been demonstrated. The system is proposed to deliver simple traffic messages between cars at low speed. The message set is programmed in an FPGA-based digital board and one of the messages is sent to the other car. Considering the outdoor and indoor environments, the effects of sunlight and fluorescent lamps on received signal waveforms are described. The delivered message is successfully recovered over 2 meter. The link for message delivery can be concatenated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.759-761
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• 2016

ICMP(Internet Control Message Protocol) supports the processing of error in the communication network based TCP/IP. If a problem is occurred in a data transmission process, router or receiving host sends ICMP message containing the error cause to sending host. However, in this process an attacker sends a fake ICMP message to the host so that the communication between the hosts can be abnormally terminated. In this paper, we performed a study to prevent several attacks related to ICMP. To this, we have designed outbound traffic controller so that attack packet is not transmitted to network in operating system of host.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6845-6848
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• 2014

This paper proposes a system design of IDS for detecting and defending against DDoS attacks on a network. The proposed system has three parts; the Alert, Attack Analyzer and Defense agent. When the server resource was reduced too much by incoming traffic, the Alert Agent sends message and traffic information to the Attack Analyzer. The message and traffic to the Attack analyzer include only the sender & receiver address and packet numbers for minimizing the overload of Attack Analyzer. Message Received Attack Analyzer investigates the Message. If the pattern of traffic is the same as the DDoS Style, the Analyzer sends a message to the Defense Agent to block that traffic. In this system, at the serious state of the server-down, the Attack analyzer uncovers the DDoS Attacker and send a message to the Defense Agent to block that traffic. This works for server reactivation as soon as possible.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.195-209
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• 2024

The current road traffic signal controller developed in the 1990s has limitations in flexibility and scalability due to power supply problems, various communication methods, and hierarchical black box structures for various equipment and devices installed to improve traffic safety for road users and autonomous cooperative driving. In this paper, we designed a road traffic safety facilities equipment and devices integrated management system that can cope with the rapidly changing future traffic environment by solving the using direct current(DC) and power supply problem through the power over ethernet(PoE) technology and centralized data-driven control through message broker technology. In addition, a data-driven real-time control method for road traffic safety facilities equipment and devices operating based on time series data was implemented and verified.

• Journal of the Korean Data and Information Science Society
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• v.21 no.4
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• pp.783-793
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• 2010

Several multi-hop applications developed for vehicular ad hoc networks use broadcast as a means to either discover nearby neighbors or propagate useful traffic information to other vehicles located within a certain geographical area. However, the conventional broadcast mechanism may lead to the so-called broadcast storm problem, a scenario in which there is a high level of contention and collisions at the link layer due to an excessive number of broadcast packets. We present a fuzzy alert message dissemination algorithm to improve performance for road safety alert application in Vehicular Ad-hoc Network (VANET). In the proposed algorithm, when a vehicle receives an alert message for the first time, the vehicle rebroadcasts the alert message according to the fuzzy control rules for rebroadcast degree, where the rebroadcast degree depends on the current traffic density of the road and the distance between source vehicle and destination vehicle. Also, the proposed algorithm is the hybrid algorithm that uses broadcast protocol together with token protocol according to traffic density. The performance of the proposed algorithm is evaluated through simulation and compared with that of other alert message dissemination algorithms.