• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1133-1141
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• 2009

In this paper, we present a distributed fault-tolerant topology control protocol that configure a wireless sensor network to achieve k-connectivity and (k+1)-coverage. One fundamental issue in sensor networks is to maintain both sensing coverage and network connectivity in order to support different applications and environments, while some least active nodes are on duty. Topology control algorithms have been proposed to maintain network connectivity while improving energy efficiency and increasing network capacity. However, by reducing the number of links in the network, topology control algorithms actually decrease the degree of routing redundancy. Although the protocols for resolving such a problem while maintaining sensing coverage were proposed, they requires accurate location information to check the coverage, and most of active sensors in the constructed topology maintain 2k-connectivity when they keep k-coverage. We propose the fault-tolerant topology control protocol that is based on the theorem that k-connectivity implies (k+1)-coverage when the sensing range is at two times the transmission range. The proposed distributed algorithm does not need accurate location information, the complexity is O(1). We demonstrate the capability of the proposed protocol to provide guaranteed connectivity and coverage, through both geometric analysis and extensive simulation.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.204-206
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• 2007

현재 전력IT 과제로 개발 중인 배전지능화 시스템은 기존의 배전망 관리뿐만 아니라 154[kV]변전소 및 수용가까지의 모든 전력설비들에 대해 원격제어가 가능하며 각종 센서들을 내장하여 해당 설비들의 상태감시를 관리하고 분산전원 설비와 연계하여 통합운영이 가능한 시스템을 말한다. 오늘날 신재생애너지에 대한 관심 증가로 인해 향후 배전계통은 분산전원과 연계되어 운영 될 것이며 이에 따른 새로운 배전관리 시스템이 필요할 것이다. 본 논문은 배전지능화 시스템에서 분산전원 설비들의 정보를 모니터링하기 위한 데이터 연계 방안을 모색하고 분산전원별 주요 감시 데이터 항목 선정 및 분산전원 설비의 정보를 전달하기 위한 분산전원 연계용 FEP(Front-End Processor)를 설계하였다.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.591-603
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• 2014

In this paper, we have described the characteristics of the Underwater Distributed Sensor Network (UDSN) and proposed the conceptual design guideline by an effectiveness analysis. To perform the effectiveness analysis, we defined an battlefield environment, and then analyzed principal components which compose the UDSN to find out simulation parameters and system constraints. We have chosen a measure of effectiveness based on a target trajectory, which could enhance intuitive understanding about current status, and performed various simulations to reveal critical design parameters in terms of sensor node types, arrangement, cost and combination of detection information.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.1
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• pp.123-131
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• 2011

In this paper, modeling and design of a distributed detection system are considered for an active sonar sensor network. The sensor network has a parallel configuration and it consists of a fusion center and a set of receiver nodes. A system with two receiver nodes is considered to investigate a theoretical aspect of design. To be specific, AND rule and OR rule are considered as the fusion rules of the sensor network. For the fusion rules, it is shown that a threshold rule of each sensor node has uniformly most powerful properties. Optimum threshold for each sensor is obtained that maximizes the probability of detection given probability of false alarm. Numerical experiments were also performed to investigate the detection characteristics of a distributed detection system with multiple sensor nodes. The experimental results show how signal strength, false alarm probability, and the distance between nodes in a sensor field affect the system detection performances.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3C
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• pp.233-240
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• 2012

Unlike traditional factory environment, in an industrial factory network applied wireless sensor network technologies, all procedures of discovery, identification and verification of devices should be performed in an automatic fashion. To address these challenges, we design a management system using the device registry server that we propose in this paper. In the phase of device discovery, the proposed system utilizes properties of routing protocol running in factories. Also, in the phase of identification and verification, the system uses unique and general information of a device stored within the device registration server. Such a way allows management system to reduce implementation complexity and to easily manage devices in a factory applied with a wireless network consisting of heterogeneous devices.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.177-185
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• 2008

Research on media access control (MAC) scheme for Wireless Sensor Network (WSN) has been mainly focused on energy efficiency improvement, while interest on latency is relatively weak. However, end-to-end latency could be a critical limitation specifically in the multi-hop network such as wireless multimedia sensor networks. In this paper we propose a media access control scheme with distributed transmission power control to Improve end-to-end transmission latency as well as reduce power consumption in multi-hop wireless sensor networks. According to the simulation results, the proposed scheme is turned out to be an energy efficient scheme with improved end-to-end transmission latency.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06a
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• pp.249-250
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• 2008

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.57-62
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• 2010

Renewable energy and smart grid become the focus of attention of industry. The smart grid is an intelligent system which maximizes the efficiency of energy and it needs to monitor the amount of power generation and power consumption continuously. Remote Monitoring System(RMS) is very useful for monitoring the power generation and consumption, but mostly they are implemented on the wire communication. In this paper, we propose a wireless sensor network based remote power monitoring system. And as an application, a new anti-islanding method with the proposed RMS is presented. An experimental micro grid system is implemented to verify the proposed RMS and anti-islanding method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2235-2241
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• 2009

RFID and USN are major technology in Ubiquitous. RFID is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders through RFID reader. USN is wireless sense network and monitoring environment conditions that is temperature, noise, pressure, oscillation. In this paper, we propose wireless sensor network system that is monitoring to optimize environment conditions.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.17-25
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• 2009

This paper presents a methodology for a fall detection using the feature extraction method based on the neural network with weighted fuzzy membership functions (NEWFM). The distributed non-overlap area measurement method selects the minimized number of input features by removing the worst input features one by one. Nineteen number of wavelet transformed coefficients captured by a triaxial accelerometer are selected as minimized features using the non-overlap area distribution measurement method. The proposed methodology shows that sensitivity, specificity, and accuracy are 95%, 97.25%, and 96.125%, respectively.