• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.925-932
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• 2015

In this paper, by utilizing the iBeacon is BLE (BlueTooth Low Energy) protocol devices that are supported by over the Bluetooth 4.0, and have implemented a system to improve the accuracy in the system for measuring the position of the user. After measuring through the system according to the state of the iBeacon, the interference factors are analyzed through analysis of the collected data, and applying the extended Kalman filter for calibration. Compared with the data after applying a filter with existing data, it was confirmed an increase in accuracy. Improvement techniques for providing the less complexity to the actual implementation, is effective in improving the accuracy of vulnerable services basic iBeacon.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.434-439
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• 2013

It is very difficult to monitor the blind spots that are not recognized by traditional surveillance camera (CCTV) systems, and the surveillance efficiencies are very low though many accidents/events can be solved by the systems. In this paper, the fuzzy logic based sound source localization system using sound strength in the underground parking lot is suggested and the performance of the system is analyzed in order to enhance the stabilization and the accuracy of the localization algorithm in the suggested system. It is confirmed that the localization stabilization of the localization algorithm (SLA_fuzzy) using the fuzzy logic in the suggested system is 4 times higher than that of the conventional localization algorithm (SLA). In addition to this, the localization accuracy of the SLA_fuzzy in the suggested system is 29% higher than that of the SLA.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.155-162
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• 2007

For providing smart home service, middleware technologies for electronic appliance control by network and user location information for location based service are important. Recently research using ultrasonic and radio signal are affected by the obstacle. In this paper, we suggest inertial sensor that is not affected by the obstacle. Also, we use RFID for initializing position. It solve error accumulation and position initialize problem. In this paper, we suggest following system for smarthome service and localization. This system are composed smarthome middleware, user localization system on middleware, inertial sensor and RFID Reader. This system shows operation without affect of obstacle in smarthome environment.

• Journal of IKEEE
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• v.24 no.1
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• pp.40-45
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• 2020

In this paper, we consider an efficient design of quantizers at sensor nodes for sequence-based localization (SBL) systems which recently show a competitive performance for in-door positioning, Since SBL systems locate targets by partitioning the sensor field into subregions, each with an unique sequence number, we use the distance samples between sensors and the sequences for quantizer design in order to propose a low weight design process. Furthermore, we present a new cost function devised to assign the number of samples and the number of unique sequences uniformly into each of quantization partitions and design quantizers by searching the quantization partitions and codewords that minimize the cost function. We finally conduct experiments to demonstrate that the proposed algorithm offers an outstanding localization performance over typical designs while maintaining a substantial reduction of design complexity.

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1436-1449
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• 2009

The value of sensing information is decided according to positions of sensor nodes, which are very important in sensor networks. In this paper, we propose a method that estimates positions of nodes by using adjacent node information and received signal strength in a sensor network. With the proposed method, we can find positions of nodes easily because we use information that nodes have. Moreover, we can find distribution easily for all the nodes because we can measure a relative position for a node whose position is not known based on anchor nodes whose positions are already known. We utilized Use case diagram, activity diagram and State machine diagram among several diagrams of UML to implement proposed method in sensor networks that is dynamic system. We can understand exact flow for each function of the proposed method in node position estimation system can be implemented easily. And we can be confirmed that the position of estimated nodes has a little error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.306-310
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• 2012

Location tracking system represents position by searching objects and humans. In this paper I would like to write about RF chip support Zigbee which is called CC2420. In simulated network circumstance, we can get the information about mobile-node by sending it to sink-node. Position finding is in error by 3m at outdoor environment. The error scale is acceptable within easy range of naked eyes. It can be overcome by using GPS information and Google maps with the wireless networking background.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.2102-2112
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• 2015

In this paper, we propose a new positioning scheme for accuracy improvement of Relay-based Navigation System. The conventional relay-based system occurs larger vertical error than horizontal one due to structural characteristics that positioning references are located toward same direction and a location of user is estimated by triangulation technique. In the proposed positioning scheme, the user position is reestimated using an additional virtual reference which is generated based on position information of reference stations in navigation signals and estimated initial user position. The nearest reference station from the estimated user position is selected as a virtual reference to minimize the effect of geometrical factor. The vertical error decreases by using reference points on multi planes, therefore, accurate positioning is possible than the conventional scheme. We demonstrated that the accuracy of a user is improved through simulation results.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.31-36
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• 2014

A study on the indoor positioning system has been active recently for the location based service indoors. In the 3 dimensional positioning system based on the acoustic signal and TDOA technology, the error characteristics of the estimated source position would be changed depending on the number of microphones and the pattern of the microphone array. In this paper, the estimated position error according to the measured distance error between the microphones and the signal source is analyzed, and the optimum microphone array is decided considering the estimated position error patterns and the total amount of the estimated position error.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.575-579
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• 2007

스마트 홈 환경에서 사용자 중심 서비스를 제공하기 위해서는 가전기기를 제어하고 네트워크에 연결하기 위한 미들웨어기술과 상황에 맞는 서비스를 제공하기 위해 사용자 위치 정보가 중요하다. 기존의 위치 시스템들은 장애물 등에 영향을 많이 받아 정확한 위치 정보를 얻을 수 없다는 단점이 있다. 본 논문에서는 OSGi 미들웨어 상에서 관성 센서와 RFID Reader를 이용하여 위치추적 시스템의 난점인 초기 위치설정 문제와 오차 누적 문제를 개선한 사용자 위치 추정 시스템을 설계하였다. 또한 스마트 홈 환경 안에서 본 논문에서 제안한 시스템이 장애물의 영향을 받지 않고 동작하는 것을 확인하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.871-872
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• 2009

FDP(Flight Data Processor) is processing of flight data for safety air traffic management. FDPs takes core function in aviation safety. Position estimation of aircraft is a key feature of the FDPs. In this paper, the requirements for position estimation of aircraft was defined.