• Journal of Advanced Navigation Technology
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• v.13 no.4
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• pp.515-522
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• 2009

In this paper, we have investigated the technology of location-aware applicable for ubiquitous environment and considered IEEE 802.15.4a IR UWB of location-aware WPAN specification which is capable of both communication of 1Mbps and wireless localization. We analyzed both system structure and the characteristic of transmission pulse as comprising of the transmitter for wireless localization of IR UWB.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.53-54
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• 2017

비콘 서비스란 가까운 범위 안에 있는 사용자 위치를 찾아 메시지 전송, 모바일 결제 등을 가능하게 하는 스마트폰 근거리통신 서비스로, O2O 실현에 핵심적인 역할을 담당한다. 비콘을 활용하면 사물과 상황인식, 콘텐츠 푸시, 실내위치 측위, 자동체크인, 지오펜스 등 다양한 서비스 제공이 가능하다. 본 연구에서는 비콘을 활용하여 출석을 체크하는 자동 출석 시스템을 구현하였다. 자동 출석 시스템에서는 사용자가 강의실에 들어오는 것을 인식하여 출석 검사를 하며, 이 자료를 인터넷을 통하여 데이터베이스에 저장한다. 다양한 강의를 구별할 수 있으며, 들어온 시간, 나간 시간 등의 검사가 가능하며, 이를 좀 더 보완한다면 상황인식 시스템으로써 다양한 서비스와 연계시킬 수 있다.

• Spatial Information Research
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• v.16 no.2
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• pp.157-171
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• 2008

With emerging technologies on wireless networks and mobile computing environment, a number of researches have been carried out for ubiquitous computing. An important functional requirement of ubiquitous computing is to handle location data with ease. With the increase of accidents in large complex buildings. move attention is being paid to indoor spaces and evacuation. However, most currently used evacuation-related applications are simulation based on hypothetical data. Also, since they use non-georeferenced CAD data, it is not easy to integrate them with indoor positioning devices. With the recent progress of indoor positioning systems, the simulators can be enhanced to real-time evacuation systems. As a preliminary stage to make such systems possible, this study proposes using a georeferenced data and evacuation simulation. This study used GIS data and Cellular Automata theory an the algorithm for the movement of the evacuee.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.160-172
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• 2018

The method of estimating a position using a GPS has been applied to various fields including a navigation system of an automobile. However, since it is difficult to measure GPS signals indoors, it is difficult to locate specific objects indoors such as a building or factory. To overcome these limitations, this study proposes a system for object location estimation based on Bluetooth5 for the management of materials in factories. The object position estimation system consists of a Bluetooth signal generator, a receiver, and a database server. A signal generator based on Bluetooth Low Energy(BLE) is attached to the material and a receiver is appropriately arranged inside the factory. In this study, we propose "Diagonal Survey Method", a 4 - axis survey algorithm using four receivers to reduce the error of existing trilateration method. The proposed algorithm showed good performance compared to the conventional trilateration and we verified the effectiveness of the proposed system and algorithm by performing the experiment by installing the system in the factory.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.8
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• pp.789-797
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• 2006

A new method for the GPS repeater based indoor positioning is proposed and its feasibility is verified by experiments in previous paper. But the problems how can identify switching GPS repeater's ID and when switching will be occurred are remained. To solve the problem faced with, we propose the time synchronized switching GPS repeater and the methods of the detection of switching time and the estimation of TDOA. First, switching GPS repeater retransmits the signals synchronized on GPS time, sequentially. Always, first switching time is synchronized with 1 PPS. Second, we formulate the detection of switching time and the estimation of TDOA and propose the various methods. No method is existed absolutely superior to others in any conditions but the method is existed superior to others in specific condition. Finally, feasibility of indoor positioning using time-synchronized switching GPS repeater is evaluated through experiments in anechoic chamber and general environment with multipath.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.9
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• pp.868-875
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• 2006

The localization is one of the most important issues for mobile robot. This paper describes a novel localization system for the development of a location sensing network. The system comprises wirelessly controlled infrared landmarks and an image sensor which detects the pixel positions of infrared sources. The proposed localization system can operate irrespective of the illumination condition in the indoor environment. We describe the operating principles of the developed localization system and report the performance for mobile robot localization and navigation. The advantage of the developed system lies in its robustness and low cost to obtain location information as well as simplicity of deployment to build a robot location sensing network. Experimental results show that the developed system outperforms the state-of-the-art localization methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.588-594
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• 2015

Although GPS technology for location positioning system has been widely used, it is difficult to be used in intelligent transport systems, due to the large positioning error and limited area for receiving radio signals. Thanks to the rapid development of LED technology, LED lights become popular in many applications. Especially, visible light communications (VLC) has raised a lot of interests because of the simultaneous functioning of LED illumination and communication. Recent studies on positioning system using VLC mainly focused on indoor environments and still difficult to satisfy positioning accuracy and simple implementation simultaneously. In this paper, we propose a positioning system based on VLC using the coordinate information of LEDs installed on the road infrastructure. Extracting the LED signal, obtained through VLC, from the easily accessible camera image, it is possible to estimate the position of the car on the road. Simulation results show that the proposed scheme can achieve a high positioning accuracy of 1 m when large number of pixels is utilized and the distance from the LED light is close.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.4
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• pp.109-117
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• 2010

With the advent of new technologies such as HSDPA, WiBro(Wireless Broadband) and personal devices, we can access various contents and services anytime and anywhere. A location based service(LBS) is essential for providing personalized services with individual location information in ubiquitous computing environment. In this paper, we propose mapping algorithm for error compensation of indoor localization system. Also we explain filter and indoor localization system. we have developed mapping algorithms composed of a map recognition method and a position compensation method. The map recognition method achieves physical space recognition and map element relation extraction. We improved the accuracy of position searching. In addition, we reduced position errors using a dynamic scale factor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2073-2078
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• 2016

Recently, there have been many research that recognize the situation using sensors. However, sensor data collection and analysis are still lacking in integration. This is because the data generated by the sensor is difficult to match in terms of metadata and units. Therefore, a methodology for efficiently using data generated from various sensors is needed. In this paper, we propose a system that recognizes the location through information generated from a moving iBeacon. This system constructs the ontology with the data that can recognize the exact position when the patient wearing iBeacon moves in the room. This maps standard items and sensor items, and stores the results of filtering the detected values as knowledge. the system can extract efficient location information by recognizing the value generated by moving the patient carrying iBeacon through the ontology. This can be applied not only to beacons but also to other sensors, and it can be applied variously according to the ontology configuration.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.959-966
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• 2015

In this paper, we propose an indoor visible light communication(VLC) localization using Walsh code which can identify overlapped signals transmitted from the different LED sources as each of orthogonal signal at a receiver and using Manchester code which can eliminate the flicker of LED light and maintain a constant brightness. The proposed system can estimate the relative position of the receiver by using Lambertian radiation properties and trilateration method that are applied to the location information of fixed LED sources and the received signals from them. In order to verify the feasibility of the proposed system, we carried out the simulation in an indoor space with $6{\times}6{\times}1.5m^3$ installed LED lamps of 16. The simulation result shows that the proposed method achieves an average positioning error of 0.0536 m and a maximum positioning error of 0.2977 m.