• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.1-8
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• 2012

In this paper, we propose an algorithm to improve collision avoidance in Vehicle-to-Vehicle (V2V) networks based on IEEE 802.11p. Since IEEE 802.11p adopts CSMA/CA as a multiple access scheme and an emergency warning message (EWM) is delivered to behind vehicles in a multi-hop manner, due to transmission collision, the more vehicles in the vehicle chain results in a longer delay. The longer delay increases the possibility of a rear-end collision. In order to ensure message reception with low latency, we consider implicit acknowledgement of a broadcasted EWM message and propose an algorithm to reduce redundant message transactions, called Two-Way Implicit Acknowledgement (TWIA). By simulations, we show that our proposed algorithm can reduce the latency until the last car receives the message by 9% and the success rate every car receives the message within 0.7sec by 12% at 100 fixed-number-of-car environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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• pp.395-404
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• 2012

In general, WBAN environment which use wearable devices on the human body show the different characteristics from other personal area networks. It is usually composed of sensors contacting the body and user terminal collecting the data from the sensors. The sensors are under the significant constraint of the energy resources, but the user terminal is different because it can be recharged and relatively have large energy resources. Under this characteristics, we design a new MAC protocol considering this requirements. The proposed MAC protocol can increase the energy efficiency of sensors and loads the unavoidable energy consumption to the user terminal for high energy efficiency of sensors. Additionally, the proposed MAC protocol provides the low delivery delay of the emergency information for the differentiated QoS because the emergency data requires more rapid transmission than the periodic sensed data. For this requirement, we employ the IFS (Inter Frame Space). For the efficient and objective evaluation of the proposed MAC protocol, IEEE 802.15.6 MAC is used to compare with it and we show that the advantage of the proposed MAC meet our expectation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9B
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• pp.1305-1313
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• 2010

Last few years, wireless personal area network (WPAN) has been widely researched for various healthcare applications. Due to restriction of device hardware (e.g., energy and memory), we need to design a highly-versatile MAC layer protocol for WBAN (Wireless Body Area Network). In addition, when an emergency occurs to a patient, a priority mechanism is necessitated for a urgent message to get through to the final destination. This paper presents a priority mechanism referred to as hybrid priority MAC for WBAN. Through extensive simulation, we show the proposed MAC protocol can minimize the average packet latency for urgent data. Thus, when patients have an emergency situation, our MAC allows adequate assistance time and medical treatment for patients. The simulation based on NS-2 shows that our Hybrid Priority MAC has the good performance and usability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.287-296
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• 2011

The white stick mainly used for visually impaired person has difficulty in providing location information and effective countermeasures for emergency situations encountered during walking as well as detecting floating obstacles on the ground. In this paper, we propose a machine-to-machine based intelligent walking assistance system for safe and convenient walking of the visually impaired. The proposed system consists of a walking assistance stick used by the visually impaired and a server supporting multiple stick users in remote places through mobile communication networks. The stick equipped with ultrasonic sensors, GPS(global positioning system) receiver and vibrator not only detects floating obstacles, but also offers stick users with present location identification utilizing a text-to-voice conversion technology. Besides providing geographic information, the server notifies the emergency locations of users to guardian and aid agency, and it provides log information during walking such as the place, time and the number of accidents. Test results with a developed prototype system have shown that the system properly performs the functions and satisfies overall system performance.

• Journal of the Society of Disaster Information
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• v.13 no.4
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• pp.550-561
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• 2017

This paper deals with the improving issues and methods for 119 dispatcher's work and training manual in order to improve their emergency response ability in Korea. Firstly, it was investigated and compared on manuals and training methods for the reception of emergency calls between South Korea and the USA. And then, specific improvement methods were considered by questionnaire for 95 dispatchers who work at 119 communication center in Gyeonggi-do in the basis of surveys. As a result, people and equipment related to 119 have been continuously upgraded, however, their work depend on their personal experiences and capabilities but because of the insufficient pretraining for the dispatchers. Also, the manpower is still insufficient overall compared to the work. Therefore, it is necessary to secure the expertise of the dispatchers through the systematic training program and proper training and test standards for 119 dispatchers, and to prevent errors in the logic of the situation and systematize their work by standardizing the response work and arranging appropriate manpower.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2354-2360
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• 2009

Healthcare is a field where ubiquitous computing is most widely used. We propose a mining-based healthcare multi-agent system for ubiquitous computing environments. This proposed scheme select diagnosis patterns using mining in the real-time biosignal data obtained from a patient's body. In addition, we classify them into normal, emergency and be ready for an emergency. This proposed scheme can deal with the enormous quantity of real-time sensing data and performs analysis and comparison between the data of patient's history and the real-time sensory data. We separate Association rule exploration into two data groups: one is the existing enormous quantity of medical history data. The other group is real-time sensory data which is collected from sensors measuring body temperature, blood pressure, pulse. Proposed system has advantage that can handle urgent situation in the far away area from hospital through PDA and mobile device. In addition, by monitoring condition of patient in a real time base, it shortens time and expense and supports medical service efficiently.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.61-81
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• 2024

eCall system assists traffic accident victims by connecting emergency rescue institutions with accurate accident information, helping them to identify the on-site situation in the event of a traffic accident. The purpose of this paper is to develop a Korean eCall system that reflects the requirements of domestic emergency rescue institutions and to analyze the expected effects through an integrated demonstration. The results of an integrated demonstration indicated that the communication success rate between the eCall IVS and the call center was 99.25%, and the average location information error was 1.2 m. In particular, it has been confirmed that the average location information error is less than 21.6 meters, as assessed by the Korea Communications Commission when evaluating the accuracy of domestic emergency rescue location information. When the eCall system was introduced, it was confirmed that the time from traffic accidents to hospital arrival could be shortened by 3 m 38 s for highways and 1 m 22 s for general roads. By it to traffic deaths from 2005 to 2022, it was analyzed that the number of fatalities decreased by 82,662, resulting in a reduction of approximately social costs.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.327-335
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• 2015

Wireless mesh networks for public safety and disaster have been developing in a direction from TETRA(TErrestrial Trunked RAdio) to take advantage of the Public Safety-LTE(Long Term Evolution) technology. In Korea, the Disaster Safety Network Building Project has been promoted in order to unify disaster communication systems among disaster response agencies. In this study, the trends of the network construction for national disaster communication and corresponding representative cases of overseas have been analyzed. Through this process, the disaster communication area in line with the purpose of communications. As a result, the disaster communication can be divided into five distinctive areas: the control, the response, the on-site, the victim and the alarm communications. Based on the re-designed communication areas, quality requirements have also been re-organized in this study. Ultimately the construction method for the Disaster Communication systems without exclusion zone will be presented.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.53-58
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• 2007

The Satellite Mobile Communication System holds several advantages, such as wide coverage that guarantees the communication in a huge area. It is suitable in the ocean and forest and especially in emergency situation. However, the licensed frequency is not always occupied within all coverage and all the time. The actual utilization rate is relatively low compared to other wireless communications such as cellular systems. There are a large amount of white spaces in its coverage. Therefore, it is necessary to consider introducing additional services such as data communication, in order to increase the spectrum utilization as well as the revenue of the Satellite service provider. In this paper, we first analyze the possibility to implement new services in the licensed band of satellite mobile phone by its provider. Then we address the most significant issue for the implementation of current service, which is how to accurately detect the satellite mobile terminals. Finally, we suggest two new possible solutions namely, eigenvalue detection based methods to find out the existence of transmitted signal from the satellite mobile terminals.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.953-958
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• 2015

Raspberry Pi is a credit card-sized computer with support for a large number of input and output peripherals. This makes it the perfect platform for interaction with many different devices and for usage in a wide range of applications. When combined with Wi-Fi, it can communicate remotely, therefore increasing its suitability for the construction of wireless sensor nodes. In addition, data processing and decision-making can be based on artificial intelligence, what is performed in developed testbed on the example of monitoring and determining the confidence of fire. In this paper, we demonstrated the usage of Raspberry Pi as a sensor web node for fire-safety monitoring in a building. When the UV-flame sensors detect a flame as thin as that of a candle, the Raspberry Pi sends a push-message to notify the assigned smartphone of the on-site situation through the GCM server. A mobile app was developed to provide a real-time video streaming service in order to determine a false alarm. If an emergency occurs, one can immediately call for help.