• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.5
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• pp.585-589
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• 2009

In this paper, passive direction-finding localization of the emitter using noisy line-of-bearing (LOB) measurements is considered. The performance of the LOB-based emitter localization using linear LSE algorithm is given. The Dependence of the performance on bias of emitter location and sensor trajectory is illustrated using the numerical results.

• Journal of the Korea Society of Computer and Information
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• v.22 no.10
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• pp.55-62
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• 2017

In this paper, we proposes a multi-ring based mobile sink location scheme for solar-powered wireless sensor network (WSN). The proposed scheme maintains the multi-rings in which nodes keep the current location of sink node. With the help of nodes in multi-rings, each node can locate the sink node efficiently with low-overhead. Moreover, because our scheme utilizes only surplus energy of a node, it can maintain multiple rings without degrading any performance of each node. Experimental results show that the proposed scheme shows much better latency and scalability with lower energy-consumption than the existing single-ring based scheme.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.2
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• pp.161-167
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• 2008

This article describes the methods of a decision of the location which user points to move by an optical device like a laser pointer and a moving to that location. Using a conic mirror and CCD camera sensor, a robot observes a spot of user wanted point among an initiative, computes the location and azimuth and moves to that position. This system offers the brief data to a processor with simple devices. In these reason, we can reduce the time of a calculation to process of images and find the target by user point for carrying a robot. User points a laser spot on a point to be moved so that this sensor system in the robot, detecting the laser spot point with a conic mirror, laid on the robot, showing a camera. The camera is attached on the robot upper body and fixed parallel to the ground and the conic mirror.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.1
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• pp.23-29
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• 2015

Energy constraints of wireless sensor networks are an important challenge. Data Transmission requires energy. Distance between origin and destination has an important role in energy consumption. In addition, the location of base station has a large impact on energy consumption and a specific method not proposed for it. In addition, a obtain model for location of base station proposed. Also a model for distributed clustering is presented by cluster heads. Eventually, a combination of discussed ideas is proposed to improve the energy consumption. The proposed ideas have been implemented over the LEACH-C protocol. Evaluation results show that the proposed methods have a better performance in energy consumption and lifetime of the network in comparison with similar methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.411-413
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• 2022

In this paper, considering the change in the sensing distance according to FoV(Fiele Of View) and the sensing distance according to the reflector, the installation location of the TOF(Time Of Flight) sensor is divided into side part installation and front/rear part installation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.11
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• pp.3145-3162
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• 2023

As an important technology of the internetwork, wireless sensor network technique plays an important role in indoor localization. Non-line-of-sight (NLOS) problem has a large effect on indoor location accuracy. A location algorithm based on improved particle filter and directional probabilistic data association (IPF-DPDA) for WSN is proposed to solve NLOS issue in this paper. Firstly, the improved particle filter is proposed to reduce error of measuring distance. Then the hypothesis test is used to detect whether measurements are in LOS situations or NLOS situations for N different groups. When there are measurements in the validation gate, the corresponding association probabilities are applied to weight retained position estimate to gain final location estimation. We have improved the traditional data association and added directional information on the original basis. If the validation gate has no measured value, we make use of the Kalman prediction value to renew. Finally, simulation and experimental results show that compared with existing methods, the IPF-DPDA performance better.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.901-920
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• 2015

Wireless Sensor Networks (WSNs) are widely used in geographically isolated applications like military border area monitoring, battle field surveillance, forest fire detection systems, etc. Uninterrupted power supply is not possible in isolated locations and hence sensor nodes live on their own battery power. Localization of sensor nodes in isolated locations is important to identify the location of event for further actions. Existing localization algorithms consume more energy at sensor nodes for computation and communication thereby reduce the lifetime of entire WSNs. Existing approaches also suffer with less localization coverage and localization accuracy. The objective of the proposed work is to increase the lifetime of WSNs while increasing the localization coverage and localization accuracy. A novel intelligent unmanned aerial vehicle anchor node (IUAN) is proposed to reduce the communication cost at sensor nodes during localization. Further, the localization computation cost is reduced at each sensor node by the proposed intelligent arc selection (IAS) algorithm. IUANs construct the location-distance messages (LDMs) for sensor nodes deployed in isolated locations and reach the Control Station (CS). Further, the CS aggregates the LDMs from different IUANs and computes the position of sensor nodes using IAS algorithm. The life time of WSN is analyzed in this paper to prove the efficiency of the proposed localization approach. The proposed localization approach considerably extends the lifetime of WSNs, localization coverage and localization accuracy in isolated environments.

• Journal of the Korean Society of Industry Convergence
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• v.10 no.2
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• pp.105-113
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• 2007

Accurate and low-cost sensor localization is a critical requirement for the deployment of wireless sensor networks in a wide variety of application. Sensor position is used for its data to be meaningful and for energy efficient data routing algorithm especially geographic routing. The previous works for sensor localization utilize global positioning system(GPS) or estimate unknown-location nodes position with help of some small reference nodes which know their position previously. However, the traditional localization techniques are not well suited in the senor network for the cost of sensors is too high. In this paper, we propose the sensor localization method with a mobile robot, which knows its position, moves through the sensing field along pre-scheduled path and gives position information to the unknown-location nodes through wireless channel to estimate their position. We suggest using the sensor position estimation method and an efficient mobility path model. To validate our method, we carried out a computer simulation, and observed that our technique achieved sensor localization more accurately and efficiently than the conventional one.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.603-610
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• 2015

This paper presents a multimodal sensor system that can determine the location of house space by analyzing the postures and heights of the residents. It consists of two sensors: a tilt sensor and an altimeter sensor. The tilt sensor measures the static and dynamic postures of the residents, and the altimeter sensor measures their heights. The sensor system includes a Bluetooth transmitter, and the server receives the measured data and determines the location in the house. We describe the process determining the locations of the residents after analyzing their postures and behaviors from the measured data. We also demonstrate the usefulness of the proposed system by applying it to a real environment.

• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.51-59
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• 2008

In wireless sensor networks, one of most common location detection methods that do not require additional devices such as GPS and ultrasonic sensor, is the location detection method based on received signal strength. However, measured received signal strength will fluctuate over time mainly due to physical radio channel characteristics between nodes, which subsequently will cause errors to measured distance between nodes. Since these contaminated distance data are utilized to detect the location of unknown node, there will be accumulated errors in the location of unknown node. In order to overcome the limitation of the location detection method based on received signal strength, we propose a location scheme in which reliability information of distance data as well as distance data between nodes are utilized to estimate the location of unknown node. Through simulation, it is shown that the proposed scheme can accomplish 30% capacity improvement.