• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1833-1841
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• 1996

Recently, by emerging of the ALE techniques that make it possible to providereliable communications link automatically, high frequency communiation is newly used as emergency communication and back-up for satellite communications. ALE signal is transmitted in burst, and the received signal is subject to distortions by detrimental multipath fading channels. In the case of that channel, the performance of ALE system is highly dependent upon that of synchronization techniques. In this paper, M-ary FSK signals are detected by a bank of bandpass filter, which is implemented using recusive DFT(Discrete Fourier Transform). Also an acquisition and trancking algorithm are designed uisng parallel structure and early-late-gate methods respectively. Finally, we verify the performance ofthe proposed synchronization algorithm by the computer simulation.

• International journal of advanced smart convergence
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• v.4 no.2
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• pp.46-53
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• 2015

This paper suggests a method of real time confidence interval estimation to detect abnormal states of sensor data. For real time confidence interval estimation, the mean square errors of the exponential smoothing method and moving average method, two of the time series analysis method, were compared, and the moving average method with less errors was applied. When the sensor data passes the bounds of the confidence interval estimation, the administrator is notified through alarms. As the suggested method is for real time anomaly detection in a ship, an Android terminal was adopted for better communication between the wireless sensor network and users. For safe navigation, an administrator can make decisions promptly and accurately upon emergency situation in a ship by referring to the anomaly detection information through real time confidence interval estimation.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.495-500
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• 2012

A standard paradigm for the allocation of wireless resources in communication demands symmetry, whereby all users are assumed to be on equal footing and hence get equal shares of communication capabilities. However, there are situations in which "prime users" should be given higher priority, as for example in the transmission of emergency messages. In this paper, we examine a prioritization policy that can be implemented at the physical layer. In particular, we evaluate the performance of a prioritized transmission scheme based on spectrum pooling and on the assignment of higher signal-to-noise ratio channels to higher-priority users. This performance is compared to that of unprioritized (or "symmetric") schemes, and the impact of prioritization on the unprioritized users is discussed.

• Journal of Communications and Networks
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• v.14 no.5
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• pp.487-494
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• 2012

A standard paradigm for the allocation of wireless resources in communication demands symmetry, that is, all users are assumed to be on equal footing and hence get equal shares of the system's communication capabilities. However, there are situations in which "prime users" should be given priority, as for example in the transmission of emergency messages. We examine prioritization policies that could be implemented at the physical layer and propose a new one, termed interference priority (IP), which is shown to have excellent performance. We evaluate the performance of these prioritization techniques both in controlled settings and within the context of a full cellular system and discuss the impact of prioritized use of resources on the unprioritized users.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1415-1423
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• 2016

Interference in device-to-device (D2D) communication underlaying cellular network needs to be elaborately investigated because of channel sharing. The objective is to improve the quality of D2D communications while maintaining high performance for cellular users. In this paper, we solve the above problem by jointly considering channel allocation and power control using coalition formation game. Our cooperative game theoric approach allows to enhance network-wide performance. We design a merge-and-split algorithm to deal with the complexity of the combinatorial structure in coalition formation problem. The analytical and numerical results show that our algorithm converges to a stable point which achieves high network performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1067-1070
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• 2004

우리는 갈수록 지능화, 분산화, 자동화 되어 가고 있는 침입에 대해 효과적으로 대처하기 위해 신경망을 적용한 침입탐지 시스템을 설계 하였다. 본 논문은 신경망을 학습시키기 위해 학습 견본과 신경망 적용 인자를 정의 하였으며 학습 기법으론 MLP(Multi Layer Perceptron)을 이용 하였다. 새롭게 설계된 침입탐지 시스템의 탐지 모듈은 기존의 패턴 매치 방식의 모듈과 신경망 모듈이 적용되어 보다 정확한 침입 탐지가 가능하다.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.109-118
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• 2022

Workers' anomalous trajectories allow us to detect emergency situations in the workplace, such as accidents of workers, security threats, and fire. In this work, we develop a scheme to detect abnormal trajectories of workers using the edit distance on real sequence (EDR) and density method. Our anomaly detection scheme consists of two phases: offline phase and online phase. In the offline phase, we design a method to determine the algorithm parameters: distance threshold and density threshold using accumulated trajectories. In the online phase, an input trajectory is detected as normal or abnormal. To achieve this objective, neighbor density of the input trajectory is calculated using the distance threshold. Then, the input trajectory is marked as an anomaly if its density is less than the density threshold. We also evaluate performance of the proposed scheme based on the MIT Badge dataset in this work. The experimental results show that over 80 % of anomalous trajectories are detected with a precision of about 70 %, and F1-score achieves 74.68 %.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.6
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• pp.63-69
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• 2009

The decentralized and open characteristic of the internet, along with the mobility and portability of mobile communication, and the interactivity of the internet and mobile communications all have been grafted to enable the creation of wireless internet in our lives, bringing about a lot of change. However, existing system management software solutions show limitations in time and space, as well as problems such as uncertain error messages, and also difficulty providing swift assistance or real time emergency support. Therefore, a wireless remote control system has been designed and implemented in this thesis, which is capable of managing and monitoring remote systems using mobile communication devices (Mobile Phone, PDA, Smart Phone, Webpad) for realtime control. The implemented real time wireless remote control system provides remote server management functions, error or event message functions, log record functions, authentication function via mobile devices and system performance evaluation function classified by client transaction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.25-28
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• 2015

Lifts are used as an essential means of transportation within the building in an emergency situation, when used as a means of escape, so expect a lot of research has been conducted high effect. Number of stories in the Seoul-rise building guidelines underground 7th floor, 53 ground floor, floor area $6,800m^2$, floor area $127,050m^2$, use is cultural and convention facilities and sales facilities, business facilities and accommodation (hotel), the construction of public housing (apartments) hagieneun not efficient to install elevators for evacuation mothada was determined separately in designing the lift is designed according to the standards of passenger lifts installed under a judgment as to use for evacuation. However, this does not include detailed design guidelines so far.[1] We propose the Evacuee Guidance of Elevator System that can be used as entering air equipment, sprinkler and smart phone evacuation system.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.1
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• pp.99-104
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• 2012

In this paper, implementation of a wireless video security system relates to a situation outside of using infrared sensors to detect changes when using Zigbee network security in the area of the sensor sends information to the server. The server can judge the situation if an emergency situation through the IP network security camera shot of the area to be transferred command to pantilte. The camera images and information in the security area, sent to administrator's smartphone users to control the camera can see the situation and More than a small video security system was designed so that user can monitor the security zone. Finally, for real-time to identify and respond to emergency situations based on the available wireless networks for video surveillance systems were verified through research and implementation.