• Journal of Advanced Navigation Technology
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• v.19 no.6
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• pp.558-563
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• 2015

There have recently been various services that use indoor location estimation technologies. Representative methods of location estimation include fingerprinting and triangulation, but they lack accuracy. Various kinds of research which apply existing location estimation methods like AOA, TOA, and TDOA are being done to solve this problem. In this paper, we study the location estimation algorithm based on AOA using a RSSI difference in indoor environments. We assume that there is a single AP with four antennas, and estimate the angle of arrival based on the RSSI value to apply the AOA algorithm. To compensate for RSSI, we use a recursive averaging filter, and use the corrected RSSI and the Pythagorean theorem to estimate the angle of arrival. The results of the experiment, show an error of 18% because of the radiation pattern of the four non-directional antennas arranged at narrow intervals.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.7
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• pp.589-596
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• 2014

Block Transporter should be optimized transportation path, otherwise it brings about lot of logistics costs and production delays. Block Transporter location must be checked in real time for optimization of transportation path. In this paper we implement real-time location determination using mobile RFID for location of Block Transporter. Mobile RFID reader mounted on a smartphone is recognize Mobile RFID Tag attached in the Transporter. Then, Smartphone is store information of every Transporter name and load and etc. Finally, Smartphone is transmit information(Mobile RFID Tag information, Transporter information, location determination information used AP and GPS) to the server. As a result, We can optimize or modify transportation path of Block Transporter in real-time using information transmitted to the server.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.181-189
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• 2001

This paper describes the positioning accuracy of GPS moduls (KGP9800C, KiRyung) which need to record the operating position of fishing boat as realtime processing in order to develope auto recording system of fishing boat's operating information, and then it's positioning accuracy for DGPS receiver (MGP-100D, Shin-A) and DGPS beacon (GP-36, Furuno) were analyzed. Futhermore, it was examined the positioning error of the GPS module with processing algorithm to minimize the effect of the signal fluctuations. The results indicate that the positioning error is able to decrease 5m as 2drms, and such improvement of positioning performance for GPS module (KGP9800C) can be provide the basic design data in the development of the auto recording system of fishing boat's operating information.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.4
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• pp.84-92
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• 2009

In this paper, using the received signal strength of radio beacon such as Wi-Fi, Bluetooth, CDMA and GPS signal from the satellite, we propose the system of positioning which considered indoor and outdoor based on the Place Lab. Conventional Place Lab utilize the various positioning parameters to estimate the indoor location. However, this conventional system has limitations with respect to the range and efficiency of usage. Therefore, we defined the converged model of multisensor data and re-organized the Place Lab to overcome the limitation of a conventional system. Proposed system uses the radio beacon signal and GPS signal together to estimate the location. Furthermore, it provides the seamless PNS service with many mobile devices because this system realized by the OSGi bundle. This proposed system has evaluated the performance with SAMSUNG T*OMNIA SCH-M490 smart phone and the result shows the system is able to support the PNS service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.217-225
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• 2015

Recently, as the supply of smart phone is spreading and the exhibition industries are rapidly growing, future exhibitions are evolving toward active, customized, interactive, tangible services, which can give more satisfaction to visitors. To realize this services, the indoor localization in the exhibition of visitors is very important and according to the accuracy of localization the quality of services for exhibition are also different. In this paper, state-of-the art indoor localization techniques are investigated and new localization method are proposed. To achieve this goal, future exhibition service types are proposed, which are connected with IT technology. And also, BLE(Bluetooth Low Energy) technology including comparison of specifications and representative localization technologies are analysed. Furthermore we performed comparison study and simulation between RF and VLC channels. Finally based on this, we proposed converged VLC and RF(Wi-Fi and BLE) localization technique for exhibition.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.1C
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• pp.87-95
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• 2010

In this paper, we propose an improved TDoA (Time Difference of Arrival) localization scheme using PSO (Particle Swarm Optimization) in UWB (Ultra Wide Band) systems. The proposed scheme is composed of two steps: re-estimation of TDoA parameters and re-localization of a tag position. In both steps, the PSO algorithm is employed to improve the performance. In the first step, the proposed scheme re-estimates the TDoA parameters obtained by traditional TDoA localization to reduce the TDoA estimation error. In the second step, the proposed scheme with the TDoA parameters estimated in the first step, re-localizes the tag to minimize the location error. The simulation results show that the proposed scheme achieves a more superior location performance to the traditional TDoA localization in both LoS (Line-of-Sight) and NLoS (Non-Line-of-Sight) channel environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2261-2270
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• 2015

GIS(Geographic Information System) based Positioning technique uses geographic information to predict which satellites are visible or invisible. GPS positioning has poor positioning accuracy in dense urban area where tall buildings block the satellite signals. In this paper, we proposed GIS based Advanced Positioning technique of Mobile GPS to resolve this problem. Particularly, this technique improves positioning accuracy in dense urban area. It is consist of ephemeris and GIS server. We will inversely estimate pseudorange by using NMEA-0183 output data of mobile GPS. After that, we can find more accurate position by using ephemeris and GIS information.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.348-350
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• 2012

현재 국토해양부에서 전국을 대상으로 실시하고 있는 지상파 DMB 기반 DGPS 실험방송의 정확도를 PC기반 수신 시스템과 내비게이션 단말을 이용하여 평가하였다. 정확도 평가를 위한 지역은 인천 송도 신도시와 서울 반포지역으로, 두 지역에 측위 경로를 선정하여 이동측위를 실시하였으며 각각 GPS 단독측위와 DMB 기반 DGPS를 이용한 측위 결과를 비교하였다. 먼저 위치보정정보의 송수신을 위하여 개발된 PC 기반 수신 시스템을 이용한 정확도 평가 결과는 송도에서 GPS 단독측위의 경우 2.5m의 수평오차가 발생하였고, DMB 기반 DGPS는 1.5m의 수평오차가 발생하였다. 또한 반포지역에서는 GPS 단독에서 2.0m, DMB기반 DGPS에서는 0.8m 수평오차가 발생하였다. 앞서 PC 기반 수신 시스템을 통해 검증 된 알고리즘을 구현한 DMB 기반 DGPS 샘플 내비게이션 단말을 이용하여 동일한 방법으로 정확도를 평가하였고 본 논문에서 그 결과를 소개한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.991-994
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• 2018

최근 사용자의 위치 정보를 기반으로 응용서비스를 제공하는 위치 기반 서비스가 각광 받고 있다. 그 중 실내 위치 정보 수집을 위한 방법 중 하나로 비콘을 사용하고 있다. 비콘을 이용하여 실내공간에서 사용자의 위치를 계산하는 방법은 비콘과 단말기와의 거리를 측정하고, 측위 알고리즘을 적용하여 단말기의 위치를 계산하는 것이다. 하지만 비콘이 단말기와의 거리를 측정하는데 사용하는 RSSI는 주변 환경에 영향을 많이 받아 측정 시 오차가 발생한다. 따라서 정확한 실내 측위를 위해서는 불안정한 RSSI를 보정할 필요가 있다. 본 논문에서는 RSSI의 오차 범위를 평균필터와 칼만필터, 그리고 신호의 정확도 개선 과정을 통해 보정하고 그 결과를 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.122-123
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• 2022

최근 들어 인공지능에 대한 발달과 많은 매체들로 인해 사람들의 관심이 증가하고 있다. 또한 GPS 나 Beacon 과 같이 위치 측위 기술이 증가함에 따라 실외 측위 기술이 많이 발달되었고, 실내에서도 사용자의 정확한 위치를 측정할 수 있는 기술들이 발달되고 있다. 본 논문에서는 RNN 알고리즘을 이용하여 비콘을 통해 수집된 사용자의 반복적이고 순차적인 위치정보, 타임스탬프 데이터를 학습시키고 ECG 를 결합하여 사용자 인증을 하여 사용자의 시간별 위치 예측과 이상 징후 탐지 시스템을 제안하고자 한다.