• 센서학회지
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• 제14권3호
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• pp.150-155
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• 2005

We propose a newly developed automobile sensor monitoring system incorporated with a tire pressure monitoring sensor(TPMS). The RF-transmitter based on a tire pressure sensor, sends a frame data about measured tire-pressure to RF receiver. And the various sensing signals based on sensors such as fuel-level sensor, engine oil level sensor and temperature sensors, are converted into 10-bit digital data. The microprocessor displays converting data such as tire pressure, trip distance, fuel quantity, coolant temperature and car-room temperature, on LCD panel. The proposed system can be successfully adapted to monitoring of the tire pressure and various automobile sensors.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권2호
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• pp.126-131
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• 2008

Wireless Sensor Network(WSNs) consists of small sensor nodes with sensing, computation, and wireless communication capabilities. It has new information collection scheme and monitoring solution for a variety of applications. Faults occurring to sensor nodes are common due to the limited resources and the harsh environment where the sensor nodes are deployed. In order to ensure the network quality of service it is necessary for the WSN to be able to detect the faulty sensors and take necessary actions for the reconstruction of the lost sensor data caused by fault as earlier as possible. In this paper, we propose an recursive PCA-based fault detection and lost data reconstruction algorithm for sensor networks. Also, the performance of proposed scheme was verified with simulation studies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권6호
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• pp.597-611
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• 2009

With the advent of ubiquitous computing society, many advanced technologies have enabled wireless sensor networks which consist of small sensor nodes. However, the sensor nodes have limited computing resources such as small size memory, low battery life, short transmission range, and low computational capabilities. Thus, decreasing energy consumption is one of the most significant issues in wireless sensor networks. In addition, numerous applications for wireless sensor networks are recently spreading to various fields (health-care, surveillance, location tracking, unmanned monitoring, nuclear reactor control, crop harvesting control, u-city, building automation etc.). For many of them, supporting security functionalities is an indispensable feature. Especially in case wireless sensor networks should provide a sufficient variety of security functions, sensor nodes are required to have more powerful performance and more energy demanding features. In other words, simultaneously providing security features and saving energy faces a trade-off problem. This paper presents a novel energy-efficient security architecture in an IEEE 802.15.4-based wireless sensor network called the Hybrid Adaptive Security (HAS) framework in order to resolve the trade off issue between security and energy. Moreover, we present a performance analysis based on the experimental results and a real implementation model in order to verify the proposed approach.

• 제어로봇시스템학회논문지
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• 제19권3호
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• pp.268-274
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• 2013

In this paper, the performance analysis of optics-based sensor node localization using ToF (Time of Flight) scheme is conducted. Generally, the position of the sensor node is calculated on the base station. And the base station scans neighboring sensor nodes with a laser. The laser which is reflected from one sensor node, however, can be reached to the base station at different angles according to the scanning resolution. This means that the error of the reached angle can increase and one node may be recognized as different nodes. Also the power of laser can decrease because the laser signal spread. Thus the sensor node which is located at a long distance from the base station cannot be detected. In order to overcome these problems which can be occurred in localization using ToF, the beam spot, the scanning resolution, the size of reflector and the power of laser at the sensor node were analyzed. It can be expected that the consequence of analysis can be provided in acquisition of accurate position of sensor node and construction of optics-based sensor node localization system.

• 중소기업융합학회논문지
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• 제4권4호
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• pp.1-6
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• 2014

무선 센서 네트워크는 여러 지역에 퍼져 있는 다수의 센서 노드들이 무선 방식으로 연결 되어있는 그물망으로 전 세계에서 연구되고 있는 기술 중 하나이다. 그러나 자원의 제약성, 무선 통신 사용 등, 네트워크 자체적인 특성으로 인해 일반 네트워크에 비해서 보안이 매우 취약하다. 무선 센서 네트워크의 공격법은 크게 도청기반 공격, 위조기반 공격, 서비스 거부 기반 공격으로 나누어지며, 보안법으로 대개의 Sensor Network Application은 전송되는 정보의 도청 또는 수정, 잘못된 정보의 삽입 등 여러가지 공격으로부터 방어를 해야 할 필요가 있다. 이를 위한 기본적인 방법은 암호화 방법, 스위칭 기법 등을 서술 한다.

• Smart Structures and Systems
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• 제30권6호
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• pp.583-599
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• 2022

In this paper, a multi-objective wireless sensor network configuration optimization method is proposed. The proposed method aims to determine the optimal information and lifespan wireless sensor network for structural health monitoring of large-scale infrastructures. In particular, cluster-based wireless sensor networks with multi-type of sensors are considered. To optimize the lifetime of the wireless sensor network, a cluster-based network optimization algorithm that optimizes the arrangement of cluster heads and base station is developed. On the other hand, based on the Bayesian inference, the uncertainty of the estimated parameters can be quantified. The coefficient of variance of the estimated parameters can be obtained, which is utilized as a holistic measure to evaluate the estimation accuracy of sensor configurations with multi-type of sensors. The proposed method provides the optimal wireless sensor network configuration that satisfies the required estimation accuracy with the longest lifetime. The proposed method is illustrated by designing the optimal wireless sensor network configuration of a cable-stayed bridge and a space truss.

• 센서학회지
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• 제15권2호
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• pp.127-133
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• 2006

Recent studies demonstrated the ability of carbon nanotube (CNT) to promote electron transfer reactions of important compounds and to impart higher stability onto electrochemical sensors. CNT-based sensors measured by hydroxyl radical concentration or pH value suggest great promise for biosensors. This paper describes a new method for fabricating a very simple and inexpensive pH sensor compose of single walled-carbon nanotubes (SW-CNTs) using an ultra-precision spray. CNT-based sensor shows pH sensitivity in buffer solution at different pH range. Our experimental results show the sensor responses to pH buffer solution and the conductance of depends on the pH values. These results support application possibility of SW-CNTs based pH sensor for mass production.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.467-470
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• 2012

본 논문에서는 센서 네트워크에서 ID 기반 인증서를 이용한 Sybil 공격 탐지 기법을 제안함으로 첫째, 효율적인 키 분배로 키 분배시 발생할 수 있는 Broadcast Storm 해결 방안을 제시하였다. 둘째, 키 체인 기법으로 센서 네트워크의 노드의 키를 생성하고, 주기적으로 변경하도록 설계함으로써 재전송 공격을 방지하였다. 셋째, 해시 함수를 사용하여 센서 노드의 신분을 인증함으로써, 센서 노드의 메모리 사용량을 극대화시켰으며, 통신 오버헤드를 줄였다. 끝으로, ID 기반 인증서를 통해 Sybil 공격을 탐지할 수 있도록 하였다. 따라서, 본 논문에서는 제안한 ID 기반 인증서를 이용한 Sybil 공격 탐지 기법은 센서 네트워크의 환경에서의 에너지 효율성과 안정성을 동시에 제공하였으며, 센서 네트워크를 통해 제공되는 정보를 신뢰할 수 있도록 하였다.

• Smart Structures and Systems
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• 제17권6호
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• pp.1031-1053
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• 2016

The health conditions of in-service civil infrastructures can be evaluated by employing structural health monitoring technology. A reliable health evaluation result depends heavily on the quality of the data collected from the structural monitoring sensor network. Hence, the problem of sensor fault diagnosis has gained considerable attention in recent years. In this paper, an innovative sensor fault diagnosis method that focuses on fault detection and isolation stages has been proposed. The dynamic or auto-regressive characteristic is firstly utilized to build a multivariable statistical model that measures the correlations of the currently collected structural responses and the future possible ones in combination with the canonical correlation analysis. Two different fault detection statistics are then defined based on the above multivariable statistical model for deciding whether a fault or failure occurred in the sensor network. After that, two corresponding fault isolation indices are deduced through the contribution analysis methodology to identify the faulty sensor. Case studies, using a benchmark structure developed for bridge health monitoring, are considered in the research and demonstrate the superiority of the new proposed sensor fault diagnosis method over the traditional principal component analysis-based and the dynamic principal component analysis-based methods.

• Journal of Communications and Networks
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• 제15권2호
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• pp.164-172
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• 2013

We consider the problem of secure and robust clustering for quantized target tracking in wireless sensor networks (WSN) where the observed system is assumed to evolve according to a probabilistic state space model. We propose a new method for jointly activating the best group of candidate sensors that participate in data aggregation, detecting the malicious sensors and estimating the target position. Firstly, we select the appropriate group in order to balance the energy dissipation and to provide the required data of the target in the WSN. This selection is also based on the transmission power between a sensor node and a cluster head. Secondly, we detect the malicious sensor nodes based on the information relevance of their measurements. Then, we estimate the target position using quantized variational filtering (QVF) algorithm. The selection of the candidate sensors group is based on multi-criteria function, which is computed by using the predicted target position provided by the QVF algorithm, while the malicious sensor nodes detection is based on Kullback-Leibler distance between the current target position distribution and the predicted sensor observation. The performance of the proposed method is validated by simulation results in target tracking for WSN.