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An Effective Route Selection Scheme with Considering Traffic Density in VANET

  • An, Do-Sik;Cho, Gi-Hwan
    • 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.

A case study on the implementation and performance evaluation of profibus network in automation systems (자동화 시스템에서 Profibus 네트워크 인터페이스 구현 및 성능 평가)

  • Kim, Ki-Am;Hong, Seung-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.1
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    • pp.113-122
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    • 1998
  • This paper presents an implementation method of Profibus interface software using FMS(Fieldbus Message Specification). The Profibus interface software is implemented on PC which is widely used as an industrial computer as well as a commercial embedded controller called IUC(Intelligent Universal Controller). In order to enable the Profibus interface software to handle many application tasks and communication services, two kinds of real-time/multi-tasking operating system, OS-9 and CTask, are utilized. We also develop an experimental model of Profibus-based automation system, and evaluate the performance of the Profibus network. Through experiments, the user layer level message latency is measured with respect to the change of message length, message generation interval and TRT(Target Rotation Time). The results of experiment are compared with those of a simulation model which comprises only the physical and data link layers of Profibus. The results of this study shows that the message latency in the user layer level occupies fairly a large part of the total message latency.

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FPGA-based Traffic Message Delivery System for Car-to-car Communications Using Visible Light Communication Link (가시광 통신링크를 이용한 FPGA기반 차량 메시지 전송 시스템)

  • Kim, Jong-Young;Cho, Eunbyeol;Hwang, Sung-Jo;Park, Bong-Seok;Lee, Chung Ghiu
    • 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.

The Effect of Message Construal Level, Temporal Distance and Consumer's SNS Self-efficacy on Consumers' Attitude Toward SNS Fashion Advertisements

  • Cho, Hyojung;Lee, Mi Young
    • International Journal of Human Ecology
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    • v.16 no.2
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    • pp.11-20
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    • 2015
  • The purpose of this study was to examine the effects of the construal level and temporal distance of a message and consumer's Social Network Service (SNS) self-efficacy on consumers' attitudes toward SNS fashion advertising. This study employed a 2 (message configuration: high construal level/low construal level) ${\times}$ 2 (temporal distance: distant future/near future) ${\times}$ 2 (SNS self-efficacy: high/low) between-subject factorial design. The survey was conducted on Facebook users in their twenties (N=216). The results are as follows: First, attitude toward SNS fashion advertising and purchase intention was higher when the message construal level was lower and when the temporal distance was closer. Second, no interactions between temporal distance and message construal level for attitude toward SNS advertising and purchase intention were found in this study. However, interactions between temporal distance and SNS self-efficacy for attitude toward SNS advertising and purchase intention were found. When the SNS self-efficacy was high, message with the low construal level reacted significantly positive in terms of attitude toward the ad as well as purchase intention. It is expected that this study will provide insight for apparel makers or retailers to use SNS as a new advertising media for fashion marketing. Practical implications and limitations are discussed.

Protocol supporting Variable-length Message using Reservation Slots in WDM Local Network (WDM Local Network에서 예약슬롯을 이용한 가변길이 메시지 지원 프로토콜)

  • 진교홍
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.2
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    • pp.257-262
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    • 2001
  • A new WDM-based protocol for scheduling a variable-length message is proposed in this paper Two control channels, reservation slot and control slot, are used to coordinate transmission and diminish the collisions of packet to minimize the across delay. When an idle control slot is available, control packet is transmitted on that slot and message is transferred. And the node continues to transmit its control packet through the corresponding slot every cycle, until the message is completely transmitted. If any control slot is not available, the node schedules the transmission time of message in earliest available time using reservation slots. The proposed scheduling algorithm shows better performance and lower access delay.

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The Design and Implementation of Messaging System(XML/EDl System) Based on Internet (인터넷을 기반으로 하는 메시징 시스템(XML/EDI System) 설계 및 구현)

  • 안경림;박상필;안정희
    • The Journal of Society for e-Business Studies
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    • v.5 no.2
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    • pp.101-112
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    • 2000
  • Costs and times, resources was better decreased than former times because it had been introduced EDI(Electronic Data Interchange) system. Nevertheless, many problems has been raised as before, that is high costs and data re-using, the rapidly changing environment, etc. To solve these problems, it was attempted to introduce XML technology at traditional EDI System. From this point to view, 1 designed and implemented XML/EDI System based on Internet(Internet Messaging System) in this paper. And I selected some services as basic service among many services which is provided at XML/EDI System, that is message sending and message receiving, message retrieval. Other service of client system was composed of MapIn and MapOut module. MapIn Module is to parse the received XML Message and to store XML Data to RDB system. And MapOut module is to generate XML Message after extracting data from RDB system and to transfer XML Message to recipient. Hereby, XML/EDI System(XEDI System) provide document re-using, the various result(output) generation f3r various requirement and directly interface with DB. Therefore, This System(XEDI System) is more various and more flexible than the existing Messaging System that just provide transfer and retrieval service

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The Emotional Effect of Emoticon on Interpreting Text Message (메시지 해석에 이모티콘이 미치는 정서적 효과 - 휴대전화 문자 메시지 상황을 중심으로)

  • Ahn, Won-Mi;Kim, Jong-Wan;Han, Kwang-Hee
    • Journal of the HCI Society of Korea
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    • v.5 no.1
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    • pp.11-18
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    • 2010
  • Cell phone users frequently send and receive text messages with emoticons in their everyday lives, but emoticon and its emotional effect on message in mobile context has not been focused on. The purpose of this study is to investigate the emotional effect of emoticons on interpretation of text message considering valent texts and emoticons. Study 1 showed the effect of valent emoticons on neutral message, and also revealed that existence of emoticon, regardless of its valence, decreases rigidness and increases familiarity of message. In Study 2 that used positive and negative text messages, we found that emoticon still affects assessing sender's mood state and emotion. Result of interaction between valences of text and emoticon showed that participants in condition of incongruent pairs felt more sarcasm.

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A Tracking System Using Location Prediction and Dynamic Threshold for Minimizing SMS Delivery

  • Lai, Yuan-Cheng;Lin, Jian-Wei;Yeh, Yi-Hsuan;Lai, Ching-Neng;Weng, Hui-Chuan
    • Journal of Communications and Networks
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    • v.15 no.1
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    • pp.54-60
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    • 2013
  • In this paper, a novel method called location-based delivery (LBD), which combines the short message service (SMS) and global position system (GPS), is proposed, and further, a realistic system for tracking a target's movement is developed. LBD reduces the number of short message transmissions while maintaining the location tracking accuracy within the acceptable range. The proposed approach, LBD, consists of three primary features: Short message format, location prediction, and dynamic threshold. The defined short message format is proprietary. Location prediction is performed by using the current location, moving speed, and bearing of the target to predict its next location. When the distance between the predicted location and the actual location exceeds a certain threshold, the target transmits a short message to the tracker to update its current location. The threshold is dynamically adjusted to maintain the location tracking accuracy and the number of short messages on the basis of the moving speed of the target. The experimental results show that LBD, indeed, outperforms other methods because it satisfactorily maintains the location tracking accuracy with relatively fewer messages.

An Enhanced Message Priority Mechanism in IEEE 802.11p Based Vehicular Networks

  • Liu, Chang;Chung, Sang-Hwa;Jeong, Han-You;Jung, Ik-Joo
    • Journal of Information Processing Systems
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    • v.11 no.3
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    • pp.465-482
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    • 2015
  • IEEE 802.11p is a standard MAC protocol for wireless access in vehicular environments (WAVEs). If a packet collision happens when a safety message is sent out, IEEE 802.11p chooses a random back-off counter value in a fixed-size contention window. However, depending on the random choice of back-off counter value, it is still possible that less important messages are sent out first while more important messages are delayed longer until sent out. In this paper, we present a new scheme for safety message scheduling, called the enhanced message priority mechanism (EMPM). It consists of the following two components: the benefit-value algorithm, which calculates the priority of the messages depending on the speed, deceleration, and message lifetime; and the back-off counter selection algorithm, which chooses the non-uniform back-off counter value in order to reduce the collision probability and to enhance the throughput of the highly beneficial messages. Numerical results show that the EMPM can significantly improve the throughput and delay of messages with high benefits when compared with existing MAC protocols. Consequently, the EMPM can provide better QoS support for the more important and urgent messages.

A performance Enhancement of VANET Warning Message Propagation on Electric Wave Blind Area Problem in the Urban Environment (도심의 전파 사각 지역 문제 해결을 위한 VANET 경고 메시지 전달 기능의 개선)

  • Lee, Won Yeoul
    • Journal of Korea Multimedia Society
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    • v.17 no.10
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    • pp.1220-1228
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    • 2014
  • Emergency Warning Service will be the most important service of VANET. Transmission delay is the most important performance criteria of the warning service. Most legacy research takes a way to minimize the packet collision. However those approach has a critical weak point on urban environment where there is a blind area of electric wave. So another issue is required in order to provide enhanced warning message propagation technique to overcome the urban environment problem. In this paper, I proposed an enhanced warning message propagation scheme in the poor electric wave environment as the intersection area. Proposed scheme forwards the warning message to the blind area by enhanced forwarding node selection technique. For efficiency of warning message propagation, I suggest forwarding priority for decision of forwarding node. And the node has a direct mode or redirect mode depending on neighbor nodes. The simulation was carried out to evaluate the performance. The simulation results show that proposed scheme has the superior performance compared to legacy warning message technique.