• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.97-104
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• 2018

In the conventional direction finding, the antenna is installed at a high position on the ground to detect the position of the target with the environment of the LOS(Line of Sight) as much as the signal receiving environment. However, in order to configure such environment, high cost and installation time were required. In this paper, we use TDOA(Time Difference of Arrival) technique to utilize drones in direction finding, so that four drones can be used for directions finding simulation. Simulations based on drone and TDOA direction finding were constructed using additional signal processing Taylor series and Exact Interactive Algorithm. In the simulation, the receiving power is defined by using the 800MHz path-loss model using the GPS information of the ground direction detection, and the position estimation performance is analyzed when the TDOA technique, the Taylor series, and the Exact Interactive Alogrithm are applied.

• Journal of Navigation and Port Research
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• v.38 no.4
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• pp.391-397
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• 2014

Wide Area Differential GNSS(WA-DGNSS) was developed in order to improve the accuracy and integrity performance of GNSS. In this paper, overall structure of Pseudolite-Based Augmentation System(PBAS) and experimental methods which enables the post-processing test with commercial receiver will be described. For generating augmenting message, GPS measurement collected from five NDGPS reference stations were processed by reference station S/W and master station S/W. The accuracy of augmenting message was tested by comparing SP3, IONEX data. In the test, RF signal of user was collected and correction data were generated. After that, RF signal was broadcasted with pseudolite signal. Test was conducted using three commercial receiver and the performance was compared with MSAS and standalone user. From the position output of each receiver, it was shown that improved position was obtained by applying augmenting message.

• Journal of Digital Policy
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• v.2 no.4
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• pp.11-15
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• 2023

Recently, a fire suddenly broke out in a crowded theater, and many people were unable to find an escape route, becoming entangled, injured, and suffocating from smoke inhalation, resulting in a large-scale fire accident. Even though most of the people were young, they were unable to evacuate. If they had been elderly, it could have resulted in greater casualties. In particular, since it is difficult to receive accurate location information from GPS indoor, there is an urgent need for location-based services using beacons and an emergency evacuation system that intuitively shows evacuation routes in augmented reality using smart-phones. In this paper, an augmented reality-based emergency evacuation smartphone app was developed based on identifying fire locations and evacuation routes using beacons and fire sensors (IoT). In the future, if the proposed system is applied to indoor spaces where people are crowded, rapid evacuation will be possible even in a sudden fire accident, minimizing human damage.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.37-39
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• 2006

최근 지상파 DMB 방송이 실시됨에 따라 이를 이용한 교통여행정보(Traffic and Travel Information, TTI)제공에 대한 관심이 증대되고 있고, 현재 DMB 방송을 통한 TPEG(Transport Protocol Experts Group) TTI 데이터 시범 서비스 실시 중에 있다. 본 논문에서는 DMB 방송의 수신 뿐만 아니라 TPEG TTI 데이터를 수신하고 이를 기존의 네비게이션 서비스와 연동하여 처리할 수 있는 DMB 방송 및 TPEG 수신 소프트웨어 디코더를 개발한다. 개발되는 디코더는 DMB가 제공하는 오디오 및 비디오 방송을 수신하면서 TPEG TTI 데이터를 GPS/GIS 모듈과 연동 처리하여 사용자에게 동적인 위치기반 네비게이션 서비스를 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.113-116
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• 2006

GPS 및 PDA 등의 발달과 보급으로 인해 위치기반서비스(LBS), 차량항법장치(CNS), 지리정보시스템(GIS)등 공간 데이터를 이용하는 응용프로그램이 급격하게 발달되었다. 응용프로그램의 발달과 더불어 이동객체의 양이 방대해짐에 따라 객체에 대한 효율적 처리가 요구된다. 이동 객체가 시간의 흐름에 따라 연속적으로 발생되는 위치 정보를 신속하게 관리하기 위한 통합된 인덱스 구조를 제안한다. 제안하는 인덱스구조는 이동 객체의 현재, 과거, 미래질의를 처리할 수 있도록 3 가지의 인덱스를 통합 하였으며, 또한 제안된 인덱스구조에 저장 관리자를 함께 둠으로써 이동 객체정보를 관리 할 수 있다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.9 no.2
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• pp.91-99
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• 2001

오늘날 위성항법, 위성통신을 이용한 항공항법감시의 새로운 변화 가운데 국제민간항공기구(ICAO)에서 VDL(VHF Digital Link) Mode 4로 채택된 STDMA (Self-organized Time Division Multiple Access)에 관심이 증대되고 있다. 해양분야에서는 선박위치 자동인식시스템(AIS) 및 선박운행관리시스템(VTS)에서 2002년부터 적용될 예정이고, 항공분야에서는 향후 몇 년후에는 ADS-B, SMGCS에서 응용될 가능성이 높다. 본 연구에서는 STDMA를 이용한 SMGCS구현을 위한 기술개발로서 사전에 측지된 기준국으로부터 실시간으로 GPS 보정값을 생성, 전송하도록 하는 실시간 DGPS기술과 동기신호에 따라 시분할 다중접속을 구현한 소프트웨어 기반의 TDMA기술을 구현하였으며 이를 연구원내에서 차량이동 실험을 수행하여 다수의 이동국간에 측위값을 상호전송함으로써 각각의 위치를 실기간으로 파악할 수 있음을 보였다.

• Korean Management Science Review
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• v.29 no.2
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• pp.79-90
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• 2012

Focusing on the rapid market penetration of smart phones, the importance of LBS (Location Based Service) is drastically increased. However, traditional GPS method has critical weakness caused by limited availability, such as indoor environment. WPS is newly attractive method as a widely applicable positioning method. In WPS, RSSI (Received Signal Strength Indication) data of all Wi-Fi APs (Access Point) are measured and stored into a huge database. The stored RSSI data in database make single radio fingerprint map. By the radio fingerprint map, we can estimate the actual position of target point. The essential factor of radio fingerprint database is data integrity of RSSI. Because of millions of APs in urban area, RSSI measurement data are seriously contaminated. Therefore, we present the unified filtering method for RSSI measurement data. As the results of filtering, we can show the effectiveness of suggested method in practical positioning system of mobile operator.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.109-110
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• 2015

본 논문에서는 Radio Frequency Identification(RFID)를 이용하여 도로의 Internet of Things(IoT)를 실현하는 기술을 구상한다. RFID태그를 도로에 일정한 간격으로 설치하고, 자동차에 설치된 RFID 리더기가 태그에서 정보를 읽고 실시간으로 중앙통제센터에 보낸다. 이 정보를 분석하여 교통량, 사고유무, 사고위치 등을 파악하여 교통문제나 2차사고를 예방한다. 이 기술의 목적은 현재 상용화된 Global Positioning System(GPS)기술이 감지하기 힘든 환경이나 Vehicle to Vehicle(V2V)가 가지는 해킹의 문제점을 보안하여 안전한 운전환경을 제공하는데 있다.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.39-42
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• 2011

본 논문에서는 지하수 관정관리의 효율성을 위해 지리정보와 USN기술 기반의 통합된 모듈을 구축한다. 이 모듈에서는 GPS 위치 값, 환경 센서(수온, 수심, 전기전도도)의 값을 CDMA 통신 모듈을 통해 서버로 전달받아서 저장한다. 관정의 위치를 GIS맵상에서 표현을 하기 위해서 실측 지도와 위성사진 자료를 이용하여 GIS맵을 구축하여 시스템 화면상에 실측지도와 함께 지리정보를 맵핑한다. 통합된 클라이언트 형태로 시스템 서비스를 제공한다.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.11
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• pp.952-959
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• 2016

This paper proposes a novel indoor positioning system (IPS) that uses a calibrated camera sensor network and dense 3D map information. The proposed IPS information is obtained by generating a bird's-eye image from multiple camera images; thus, our proposed IPS can provide accurate position information when objects (e.g., the mobile robot or pedestrians) are detected from multiple camera views. We evaluate the proposed IPS in a real environment with moving objects in a wireless camera sensor network. The results demonstrate that the proposed IPS can provide accurate position information for moving objects. This can improve the localization performance for mobile robot operation.