• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1195-1207
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• 2012

Fast and reliable message broadcasting is critical for safety critical applications of VANET due to the urgency and/or significance of the messages for passengers and drivers. For reliable message delivery, a mechanism for checking the reception of message at the neighboring vehicles and retransmitting it if necessary is required. Especially, in urban environments, where the traffic density tends to be high, mechanisms that minimize control message overhead such as beacon are appropriate in order to minimize the message collisions. Furthermore, broadcast delivery is especially difficult at the intersection due to the road side obstacles such buildings, and hence, a mechanism that enables effective and efficient delivery across intersections is required. In this paper, we propose a beaconless reliable and efficient broadcast approach which specifically taking into account the urban streets. The proposed approach checks the message reception of neighboring vehicles implicitly by taking into account the broadcast of message by next vehicle as the acknowledgement. When retransmissions is necessary around the intersections, vehicles located within the intersection area, where the chance of successful signal propagation toward every branch of the intersection is higher due to less signal attenuation caused by road side obstacles, are to do the retransmissions. Simulation results show that the proposed approach can provide better reliability while consume less resources than the existing approaches.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3672-3679
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• 2012

Vehicle Ad hoc Network (VANET) is next-generation network technology to provide various services using V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure). In VANET, many researchers proposed various studies for the safety of drivers. In particular, using the emergency message to increase the efficiency of traffic safety have been actively studied. In order to efficiently transmit to moving vehicle, to send a quick message to as many nodes is very important via broadcasting belong to communication range of vehicle nodes. However, existing studies have suggested a message for transmission to the communication node through indiscriminate broadcasting and broadcast storm problems, thereby decreasing the overall performance has caused the problem. In addition, theses problems has decreasing performance of overall network in various form of road and high density of vehicle node as urban area. Therefore, this paper proposed Clustering based Routing Algorithm (CBRA) to efficiently transmit emergency message in high density of vehicle as urban area. The CBRA managed moving vehicle via clustering when vehicle transmit emergency messages. In addition, we resolve linkage problem between vehicles according to various form of road. The CBRA resolve link brokage problem according to various form of road as urban using clustering. In addition, we resolve broadcasting storm problem and improving efficacy using selection flooding method. simulation results using ns-2 revealed that the proposed CBRA performs much better than the existing routing protocols.

• Nuclear Engineering and Technology
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• v.46 no.5
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• pp.707-718
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• 2014

As a result of conducting a 45 minute-long seminar on the principles, state of use, advantages, and disadvantages of nuclear power generation for Korean elementary, middle, and high school students, the levels of perception including the necessity (p<0.017), safety (p<0.000), information acquisition (p<0.000), and subjective knowledge (p<0.000), objective knowledge (p<0.000), attitude (p<0.000), and behavior (p<0.000) were all significantly higher. This indicates that education can be effective in promoting widespread social acceptance of nuclear power and its continued use. In order to induce behavior change toward positive judgments on nuclear power generation, it is necessary to focus on attitude improvement while providing the information in all areas related to the perception, knowledge, attitude, and behavior. Here, the positive message on the convenience and the safety of nuclear power generation should be highlighted.

• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.435-439
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• 2010

In Korea, food-risk shock announcements are made one or more times annually; such as last September, 2010 when Seoul City revealed a very high concentration of cadmium in small octopus intestines sold in Korea. As a result, consumers avoided eating domestic as well as imported small octopus. Fishermen protested against Seoul city; however, the Korean Food and Drug Administration (KFDA) announced that small octopus intestines pose no safety risk. The conflict between KFDA and Seoul City on the safety of small octopus intestines amplified the confusion of consumers. The small octopus cadmium shock resembled previous food-risk shocks in many respects. Effective risk communication is important in resolving food risk shocks as risk affects people case-by-case; for example people who do not eat small octopus intestines should not be at any risk, but those who do enjoy small octopus intestines, especially one more times per week, could be at risk. Therefore, it is necessary to communicate different risk messages to people or groups with different eating habits. From this point of view, the risk message conveyed by the KFDA on small octopus intestines was not appropriate.

• Journal of the Korea Society of Computer and Information
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• v.27 no.8
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• pp.169-176
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• 2022

With the continuous development of technologies related to 5G, artificial intelligence, and autonomous vehicle systems, standards and services for V2X and C-ITS environments are being studied a lot. BSM (basic safety message) was adopted as a standard for exchanging data between vehicles based on data collected and generated by vehicle systems in a V2V environment. In this paper, we propose a framework that can safely store BSM messages and effectively check the stored messages using Event-Sourcing and CQRS patterns. The proposed framework can securely store and manage BSM messages using hash functions. And it has the advantage of being able to check the stored BSM data in real time based on the time series and to reproduce the state.

• Journal of Auto-vehicle Safety Association
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• v.14 no.1
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• pp.45-54
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• 2022

Recently, the introduction of Cooperative Intelligent Transport Systems (C-ITS) has been attempted to solve the limitation of only the sensor of the vehicle itself. For example, vehicles traveling at intersections can drive more safely through C-ITS. By using V2X communication of WAVE and LTE, the driver can receive the status and time of traffic lights. However, LTE has a larger transmission delay time than WAVE, so timimg data may not match in real time. In this paper, using the SPaT message, it was confirmed that LTE has a larger C-ITS service transmission delay time than WAVE. Finally, it was confirmed that the timing data of SPaT provided by LTE corrected by the algorithm is similar to SPaT provided by WAVE. It was confirmed that safer intersection driving is possible based on real-time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.624-627
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• 2014

In vehicular network, the basic goal is to provide vehicle safety service and commercial service such as ITS(Intelligent Transportation System) or video, etc on the road. And most research concentrated on transportation of safety message in congestion situation. It is important to allocate channel for safety message in congestion situation, but providing suitable service is also important problem in vehicular network. For this reason, IEEE 1609.4 allocate 4 multiple service channels (SCHs) for non-safety data transfer. But, in congestion situation with many vehicles, the contention for channel acquisition between services becomes more severe. So services are provided improperly because of lack of service channel. This paper suggests dynamic channel allocation algorithm. The proposed algorithm is that RSU(RaodSide Unit) maintain and manage the information about service and status of channels. On based of the SJF(Shortest Job First) scheduling using those information, RSU selects the most appropriate channel among the 4 SCHs allocated by IEEE 1609.4 in network congestion situation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.100-101
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• 2012

According to growing the leisure boat market, safety-related and weather information have been required by different users with different electronic devices. NAVTEX messages transmitting worldwide from local stations are a kind of useful service, even for non mandatory carriage requirement vessel, such as small or fishing vessels. However, it is not easy for all users to recognize intuitively. This paper is to implement the NAVTEX message on tablet PC, indicating warning positions of message on Android-based google map.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.157-165
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• 2004

Real-time(RT) object-oriented(OO) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO(Time-triggered Message-triggered Object)structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established OO programming languages such as C++ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems. Start after striking space key 2 times.

• Journal of information and communication convergence engineering
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• v.1 no.1
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• pp.12-22
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• 2003

Real-time(RT) object-oriented(OO) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO (Time-triggered Message-triggered Object) structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established OO programming languages such as C++ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems