• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.31-37
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• 2017

Recently, governmental authority and local government are looking for a method of utilizing location information of smart phone for urgent rescue in fire and kidnap situation. Under this background, in this study, a method of rapidly collecting, constructing location determination based Wi-Fi AP data utilizing location information of smart phone and mobile mapping system was suggested in order to construct precise positioning information that could be utilized under urgent situation. By performing compensation work for GPS/INS/DMI through collected outcome, position of collected vehicle was acquired. In addition, source data integrating Wi-Fi information and collected position by coupling based on Wi-Fi AP collector and GPS time was constructed and Wi-Fi radiomap was constructed by removing Wi-Fi signal noise that reduces precise position performance. As a result of performing location determination performance assess ment by selecting 10 test positions by each local government, result value of 25.46cm for total local government average and 27.76m for SD could be obtained. It is considered that this result could be utilized as a technology of being able to supplement or substituting GPS location determination technology that is impossible in plocation determination of mobile communication company's base station (200m~2km) and indoor being used at present.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.1
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• pp.66-77
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• 2006

In this paper, we researched the searching and tracking locations of a home resident using ON/OFF switches and sensors and designed a remote monitoring system. As an implementation environment, this system is developed on the base of the distributed object group framework we have developed from previous works. In order to trace the moving locations of a home resident, we firstly showed a home structure which attaches ON/OFF switches and sensors to home appliances and indoor facilities being fixed in home. Whenever a home resident opens/closes these objects, the signals operated from ON/OFF switches and sensors are sent to a home server system. In this time, the real locations of ON/OFF switches and sensors that the signals are being occurred must be the current location that he/she stays. A home server system provides the functionalities that map the real location of a resident in home to virtual location designed on remote desk-tops or terminals like PDAs, and that construct a healthcare database consisted of moving patterns, moving ranges, momentum for analyzing the given searching locations and times Finally, this system provides these information for remotely monitoring services.

• Fire Science and Engineering
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• v.29 no.6
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• pp.98-108
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• 2015

An integrated command system is critical for the safety of firefighters and effective work in the headquarters of a special disaster areas such as natural disaster or large man-made hazard. The integrated command system requires environmental information such as temperature, humidity, and $CO_2$ levels, as well as personal physical information such as pulse and air respirator levels. An Analog to Digital Converter (ADC) chip converts sensed information into digital signals, and a Micro Controller Unit (MCU) transmits the digital signals to a transmission board using serial communication through a Serial Peripheral Interface (SPI). The digital signals are saved in a transmission board and transmitted to the integrated command system by a Radio Frequency (RF) unit. The location of fire-fighters in a building are determined using a gyro sensor and an inertial sensor. The collected information is applied to the integrated command system for firefighter safety and to ensure that they can effectively carry out their duties. Tthis study theoretically and experimentally investigated the technologies of RF transmission, indoor position, and an integrated command system that supports decision making using the transmitted information.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.81-84
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• 2007

In this research, we will accomplish the investigation of the devices and data models which are used in the existing indoor and outdoor systems. Based on the investigation, we will seize the additional requirements for the integration of the legacy system and then we will propose the various methods which support the additional requirements. By applying the various methods in the heterogeneous environments, we will solve the legacy problems and propose the methods for the final goal that is to provide the seamless moving object tracking. The scope of this research is to propose the integration methods, developing the actual location tracking system model without modifying the legacy infrastructures.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.812-817
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• 2006

박물관이나 전시실과 같은 실내 공간에서 관람객들은 관심을 갖는 대상물에 대한 위치 추적과 컨텐츠 정보를 실시간적으로 볼 수 있는 방법을 요구하고 있다. 이를 위하여 본 연구에서는 크리켓(Cricket) 센서 네트워크 기술을 활용한 실내 위치 추적 시스템과 모바일 RFID을 통한 실시간 컨텐츠 전송 시스템을 개발하였으며 그 결과를 기술하였다. 본 논문에서는 프로토타입의 설계 및 구현하는 과정을 통하여 센서네트워크(크리켓)와 RFID 시스템의 연동 방식이 다양한 분야에서 유용하게 사용될 수 있음을 보이고 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3A
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• pp.288-292
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• 2004

Recently the application area of wireless LAN has been increased, rapidly. The application area was limited in indoor, but as the data throughput and performance of wireless LAN becomes better the application is to extend to the Internet connection and wireless bridge in outdoor. In this paper, the data throughput of wireless LAN in mobile environment is measured, and the usability of wireless LAN for ITS, Telematics, and LBS is confirmed.

• Information and Communications Magazine
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• v.32 no.2
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• pp.13-23
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• 2015

Real Time Location System(RTLS)는 실시간으로 사물의 위치 정보 측위를 통해 다양한 서비스를 제공하는 시스템을 말한다. RTLS 시스템은 물류, 헬스케어, 생산 시설 등 사물인터넷(IoT, Internet of Things)과 관련된 다양한 분야에서 활용되고 있다. 최근에는 경마, 미식축구 및 발레 등 여러 스포츠 종목에 도입하고자 하는 시도가 늘고 있어 동계올림픽의 각 종목을 위한 훈련, 분석, 서비스 등에의 적용을 위한 개발을 적극적으로 검토할 필요가 있다. 통상적으로 실시간 위치 추적 시스템(RTLS)은 근거리 및 실내와 같은 제한된 공간에서의 위치 확인 및 위치 추적 시스템을 통칭하고, 이동통신망 기반의 위치기반 서비스(LBS) 처럼 사람 또는 사물의 위치를 확인하지만 주로 제한된 공간에 활용되므로 '실내위치 추적 서비스(IPS: Indoor Positioning System)'라고 불리기도 한다. 본고에서는 먼저 RTLS의 기술과 이를 스포츠에 접목하기 위한 사례를 중심으로 그 동향을 분석한다.

• Journal of Digital Contents Society
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• v.18 no.4
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• pp.761-768
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• 2017

As the loss prevention system using bluetooth has a short communication range, it has a problem which its location is not known if it is strayed out of a certain distance. To overcome shortcoming of such an existing loss prevention system, this paper proposes a GPS-based wireless loss prevention system without communication fee using the LoRa Communication with a long distance. The proposed system performs a remote control application on the smart-phone and then is able to get a long-distance GPS coordinates about the location of the loss prevention system on the google map. For performance evaluation of the implemented proposed system, the experiments for transmitting and receiving data are done in open terrain, indoor and outdoor areas and the experiment results identified the superiority of the proposed system in the long-distance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.127-134
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• 2015

VLC(Visible Light Communication) is the technology to send and receive data by using visible light that LED emits. The basic principle of VLC is the communication by using flashing(ON/OFF) of the light from the LED that changes electricity to light in short time. As the recent advances in LED technology, VLC is also received a lot of attention and the research about it is in progress actively. Especially, the interest about indoor VLC system is increasing because the visible light can't pass through the wall. In this paper, we compose the indoor SISO VLC system with NRZ-OOK and VPPM modulation schemes. Also, we apply SR-ARQ, a kind of re-transmission error control schemes, to the VLC system. And then, we compare and analyze the performance of communication according to the location of receiver and the type of modulation by using BER, the number of transmission and throughput.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.996-1001
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• 2005

Recently, with the development of service robots and with the new concept of ubiquitous world, the position estimation of mobile objects has been raised to an important problem. As pre-liminary research results, some of the localization schemes are introduced, which provide the relative location of the moving objects subjected to accumulated errors. To implement a real time localization system, a new absolute position estimation method for a mobile robot in indoor environment is proposed in this paper. Design and implementation of the localization system comes from the usage of active beacon systems (based upon RFID technology). The active beacon system is composed of an RFID receiver and an ultra-sonic transmitter: 1. The RFID receiver gets the synchronization signal from the mobile robot and 2. The ultra-sonic transmitter sends out the traveling signal to be used for measuring the distance. Position of a mobile robot in a three dimensional space can be calculated basically from the distance information from. Three beacons and the absolute position information of the beacons themselves. In some case, the mobile robot can get the ultrasonic signals from only one or two beacons, because of the obstacles located along the moving path. Therefore, in this paper, as one of our dedicated contribution, the position estimation scheme with less than three sensors has been developed. Also, the extended Kalman filter algorithm is applied for the improvement of position estimation accuracy of the mobile robot.