• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.2
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• pp.141-154
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• 2013

The technology of precise time-synchronization between signal receive devices for separation distance operation can be a key point for the technology with TDoA-based system. We propose a new method for the higher accuracy of system's time-synchronization in this paper, which uses OCXO and DPLL with high accuracy to achieve phase synchronization at 1 pps (pulse per second) of signal. And the method receive time value from a GPS satellite. Essentially, the performance of GPS with high accuracy refers to long-term frequency stability for its reliability. As per the characteristic, as the GPS timing signals are synchronized continuously, the accuracy of time-synchronization gets improved proportionally. Therefore, if the time synchronization is accomplished, the accuracy of the synchronization can be up to 0.001 ppb (part per billion). Through the improved accuracy of the time-synchronization, the measurement error of TDOA-based location detection technology is evaluated. Consequently, we verify that TDoA-based location measurement error can be greatly improved via using the improved method for time-synchronization error.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.432-433
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• 2012

조선 산업 현장에서 선박 건조 공정에서 생산된 선박 블록에 대해 조선소 야드 내 위치를 식별하는 것이 필요하다. 본 논문은 사용자가 3G 무선통신 기반의 모바일 기기를 이용하여 물류상황을 파악하고, 현장에서 직접 블록의 위치를 선박물류시스템에 입력할 수 있는 GPS 기반 위치 인식 시스템을 제안한다.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.3
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• pp.27-34
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• 2013

As smart phone is daily used by most people, various location-based applications have been developed. Moreover, it is increased the requirements of location-based services that utilize Google maps, GPS sensing information and etc.. In this paper, we develop a smart phone application providing notification services by detecting the daily route deviation. We develop the server system which receives GPS information gathering from user's smart phone and analyse the user's regular routes. With the results from the analyzation the GPS coordinates, the application on a smart phone detects the case of a breakaway from regular routes. And then it can inform automatically and immediately the designed person such as guardians of children or the old and the infirm of the route deviation so will be helpful to protect such person. This is one example of the effectiveness of the application. Moreover, the application is developed on the client-server framework, thus it is very useful to judge the user's daily route deviation in realtime by using the accumulated information on the corresponding DB. Finally we evaluated the proposed methods which had been implemented on smart phones and show the utilities of the application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.609-617
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• 2016

In general, Personal Navigation Systems (PNSs) can be defined systems to acquire pedestrian positional information. GPS is an example of PNS. However, GPS can only be used where the GPS signal can be received. Pedestrian Dead Reckoning (PDR) can estimate the positional information of pedestrians using Inertial Measurement Unit (IMU). Therefore, PDR can be used for GPS-disabled areas. This paper proposes a PDR scheme considering various movement types over GPS-disabled areas as combat environments. We propose a movement distance estimation scheme and movement direction estimation scheme as pedestrian's various movement types such as walking, running and crawling using IMU. Also, we propose a fusion algorithm between GPS and PDR to mitigate the lack of accuracy of positional information at the entrance to the building. The proposed algorithm has been tested in a real test bed. In the experimental results, the proposed algorithms exhibited an average position error distance of 5.64m and position error rate in goal point of 3.41% as a pedestrian traveled 0.6km.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.5
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• pp.329-334
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• 2013

A positioning based service uses one's position information with GPS. This application also use the position based characters and change the smart phone to the vibration mode at the registered position. If the user register some places to be vibrated in the smart phone, the smart phone will be automatically changed to the vibration mode as the registered position is same with the position of GPS in the smart phone. If the smart phone is being leaving some distance from the position, the phone will be released from the vibration mode. Therefore, this paper propose aims for intelligent smart phone.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.1
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• pp.94-106
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• 2020

Recently, the radio navigation method utilizing the GPS(Global Positioning System) satellite information is widely used as the method to measure the position of objects. As GPS applications become wider and fields based on various positioning information emerge, new methods for achieving higher accuracy are required. In the case of autonomous vehicles, the INS(Inertial Navigation System) using the IMU(Inertial Measurement Unit), and the DR(Dead Reckoning) algorithm using the in-vehicle sensor, are used for the purpose of preventing degradation of accuracy of the GPS and to measure the position in the shadow area. However, these positioning methods have many elements of problems due not only to the existence of various shaded areas such as building areas that are continually enlarged, tunnels, underground parking lots and but also to the limitations of accumulation-based location estimation methods that increase in error over time. In this paper, an efficient positioning method in a large underground parking space using Fingerprint method is proposed by placing the AP(Access Points) and directional antennas in the form of four anchors using WLAN, a popular means of wireless communication, for positioning the vehicle in the GPS shadow area. The proposed method is proved to be able to produce unchanged positioning results even in an environment where parked vehicles are moved as time passes.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.88-93
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• 2003

국토공간정보의 기반인 수치지도 제작을 위해서는 위치에 대한 정확한 정보가 요구되며 이러한 정보는 GPS를 이용한 방법이 대표시 되고 있다. 우리나라도 GPS를 이용한 위치결정 방법의 효율성과 정확성을 확보하기 위해 전 국토에 걸쳐 24시간 위성데이터를 취득할 수 있는 70여개의 GPS 상시관측소를 설치 운영하고 있다. 따라서 본 연구는 GPS 상시관측소 데이터의 효과적인 활용 방안을 모색하기 위해 행정자치부와 국리지리원에서 설치 운영하며 호남권에 위치한 5곳의 상시관측소를 대상으로 각기 고정위치를 달리하여 기선해석과 망조정을 수행하여 고정위치에 따른 3차원 절대좌표의 정밀도를 분석하였다. 현재 행정자치부의 3곳의 상시관측소 절대위치는 고시되지 않아 국립지리원 고시 성과를 기준으로 고시성과와 계산성과의 3차원 절대 좌표를 비교하였다.

• 한국IT서비스학회:학술대회논문집
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• 2009.11a
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• pp.55-58
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• 2009

위치기반 서비스는 사용자의 위치를 자동으로 인식하여 사용자의 위치를 고려한 맞춤형 서비스를 제공하며, 일반적으로 위치정보 획득을 위해 GPS(Global Positioning System)를 이용하고 있다. 본 논문에서는 GPS 수신기를 통해 수신된 정보로부터 차량의 위치정보를 인식하고, 이를 사전에 설정된 관광 차량의 이동경로와 비교 분석하여 안내 방송이 필요한 각 관광지까지의 거리와 소요시간 등을 실시간으로 인식한다. 또, 이러한 인식결과를 이용하여 사전 또는 실시간으로 설정된 관광지의 멀티미디어 관광 콘텐츠를 영상과 음성으로 재생하여 관광객에게 제공하게 된다. 특히, 각각 사용 언어가 다른 사용자가 동시에 서비스를 이용하더라도 별도의 음성채널을 통하여 서비스를 제공하며, 사용자 수신기에서 채널을 선택하여 이용하므로 사용자 편의성을 높일 수 있다.

• The Journal of the Korea Contents Association
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• v.11 no.2
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• pp.135-141
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• 2011

Mobile communication technology in the field of ubiquitous computing is one of important technologies. The development of GPS technology in mobile communications technology and PDA, the vast majority of mobile devices such as smart phones also being equipped with GPS functionality. This user where they are located where they are based on the number of through services were able to receive information. In this paper, mounted on a mobile device user's location using GPS capabilities to track the migration routes and the accumulated user to determine the migratory path of the system used to recommend the proposed route of the proposed method and system Designs. The services offered by tracking the location of the user to move the user to route data to create and upload to the server. Upload a migration path to move data from where they currently reside to the user is recommended to go to your destination. The services offered by the users do not know where to travel or go to your destination, etc. If you do not remember the path can be useful.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.313-314
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• 2022

The intelligent maritime traffic information service provides a service to prevent collisions and stranding of ships based on the location information of ships periodically collected from ship equipment such as LTE-Maritime transceivers and AIS installed on ships. provided in real time. However, the above service may reduce the reliability of ship location information because GPS location information for measuring the ship's location may be cut off during transmission through LTE-Maritime or AIS networks, or phenomena such as location jumps and delays may occur. This study aims to estimate reliable position information to some extent even in an abnormal section through ship position prediction based on the existing received position information using the Kalman filter, which is an optimal estimation filter based on probability.