• Title/Summary/Keyword: GPS time

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Spliting polios of interval R-Trees for tracking RFID tag objects (전자태그 객체의 추적을 위한 간격 R-트리의 분할 정책)

  • Lee, Se-Ho;Ahn, Sung-Woo;Hong, Bong-Hee;Ban, Chae-Hoon;Lim, Duk-Sung
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.07b
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    • pp.40-42
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    • 2005
  • RFID(Radio Frequency Identification)는 자동 인식 데이터 수집 장치의 한 분야로써 GPS장치를 장착한 차량과 같이, RFID 태그(전자태그)를 상품에 부착하여 인식, 추적할 수 있다. 이러한 전자태그 객체는 시간에 따라 경로 정보가 누적되는 이동체와 유사한 특성을 가진다. 그러나 기존의 이동체 색인과 달리 태그 객체의 위치는 판독기의 위치로 인식되며 위치보고가 판독기의 인식영역 안에서만 이루어지므로 보고 주기를 예측할 수 없다. 기존의 이동체 색인에서 전자태그의 특성을 표현하기 힘들기 때문에 전자태그의 특성을 고려란 색인이 필요하게 되었다. 최근 전자태그의 특성을 고려한 색인인 TPIR-Tree(Time parameterized Interval R-Tree)가 발표되었다. 그러나 이 색인은 기존 공간 색인에서의 균등분할 기법을 사용하여 위치보고가 시간의 순서를 가지는 전자태그의 특성을 고려하지 못하여 과거노드의 저장효율이 좋지 못하다. 이 논문에서는 TPIR-Tree의 저장효율 및 검색 성능 향상을 위해서 시간의 순서에 따라 위치를 보고하는 전자태그 객체의 특성을 고려하여 분할축 선정 기법 및 시간축 분할시 비균등 분할정책을 제안한다.

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A Study on the Development of Simple DGPS for the Coastal Survey (연안 해양 관측을 위한 간역 DGPS 개발 연구)

  • 이상룡;문동준;전호경
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.1
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    • pp.10-17
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    • 1996
  • A real time simple DGPS (SDGPS) for coastal survey is developed and in situ tested. While the accuracy of the system is almost the same as that of existing commercially available DGPS, it is very economical compared to the commercial ones. The RMS error of the positions fired by the system is estimated to be less than 2 m within the range of 30 km from the reference station. Even if the coordinates of the reference station are uncertain, they can be fixed, from the continuous GPS observation of one day, with the maximum error less than 1 m. The system is believed to be helpfully utilized to most of coastal surveys despite of some minor defects.

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Study on Reliability of New Digital Tachograph for Traffic Accident Investigation and Reconstruction (교통사고 조사 및 재현에서 신형 전자식운행기록계의 신뢰성에 관한 연구)

  • Park, Jongjin;Joh, Geonwoo;Park, Jongchan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.6
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    • pp.615-622
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    • 2015
  • Recently Digital-TachoGraph(DTG) was mounted mandatorily in commercial vehicles(Taxi, Bus, etc.). DTG records accurate and detailed information of the running state of vehicles related to traffic accident, such as Time, Distance, Velocity, RPM, Brake ON/OFF, GPS, Azimuth, Acceleration. Thus those standardized data can play an important role in traffic accident investigation and reconstruction. To develope the accurate and objective method using the DTG data for the reconstruction of traffic accident, we had conducted several tests such as driving test, high speed circuit test, braking test, slalom test at Korea Automobile Testing & Research Institute(KATRI), and collision test at Korea Automobile insurance repair Research and Training center(KART) with the vehicle equipped with several DTG. Development of the program which enables the reading and analysis of the DTG data was followed. In the experiments, we have found velocity error, RPM error, brake signal error and azimuth error in several products, and also non-continuous event data. The cause of these errors was deduced to be related to the correction factor, the durability of electronic parts and the algorithm.

Performance Analysis and Development of the Navigation System for Pipeline Inspection Gauge (배관 진단 시스템을 위한 항법 시스템 개발과 성능 분석)

  • Jin Yong;Park Chan Gook;Woo Rho Yong
    • Journal of the Korean Institute of Gas
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    • v.6 no.1 s.17
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    • pp.52-58
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    • 2002
  • The PIG(Pipeline Inspection Gauge) is inserted in the pipeline and stores data of pipeline. In order to investigate the status of pipeline, a lot of sensors such as caliper, pressure, IMU and odometer are used. In this paper, the navigation storage data system for PIG is developed. It has master/slave structure for a real time operation. The master system stores data, while the slave system acquire the data from sensors. The performance of the developed system is verified by pull rig test.

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The Application of Satellite Positioning Technology and its Industrialization in China

  • Lizhong, Zheng;Xiuwan, Chen
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.331-336
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    • 2002
  • Satellite positioning technology has been widely used in all kinds of military and civil land, marine, space and aeronautical target positioning tasks, navigation activities and accurate surveying measurements since 90s in the last century due to it advantage in providing all-weather, real-time, three dimensional and high precision positioning information, as well as speed and accurate timing information. By now, it has already formed a new hi-tech industry basically. This paper briefly reviews the development of the global satellite positioning and navigation technologies including the basic information of China′s "Plough navigation system", introduces the history of satellite positioning technology and its major application fields as well as the status quo of this being industrialized trade in China, gives an account of the writers′ vision for the application and prospect of the satellite positioning technologies in China, and approaches the tactics and stresses of the satellite positioning technology′s application and its industrialization future in China.

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Direct Geo-referencing for Laser Mapping System

  • Kim, Seong-Baek;Lee, Seung-yong;Kim, Min-Soo
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.423-427
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    • 2002
  • Contrary to the traditional text-based information, 4S(GIS,GNSS,SIIS,ITS) information can contribute to the citizen's welfare in upcoming era. Recently, GSIS(Geo-Spatial Information System) has been applied and stressed out in various fields. As analyzed the data from GSIS arena, the position information of objects and targets is crucial and critical. Therefore, several methods of getting and knowing position are proposed and developed. From this perspective, Position collection and processing are the heart of 4S technology. We develop 4S-Van that enables real-time acquisition of position and attribute information and accurate image data in remote site. In this study, the configuration of 4S-Van equipped with GPS, INS, CCD and eye-safe laser scanner is shown and the merits of DGPS/INS integration approach for geo-referencing is briefly discussed. The algorithm of DGPS/INS integration fur determination of six parameters of motion is eccential in the 4S-Van to avoid or simplify the complicated computation such as photogrammetric triangulation. 4S-Van has the application of Laser-Mobile Mapping System for three-dimensional data acquisition that merges the texture information from CCD camera. The technique is also applied in the fields of virtual reality, car navigation, computer games, planning and management, city transportation, mobile communication, etc.

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Location Based Routing Service In Distributed Web Environment

  • Kim, Do-Hyun;Jang, Byung-Tae
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.340-342
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    • 2003
  • Location based services based on positions of moving objects are expanding the business area gradually. The location is included all estimate position of the future as well as the position of the present and the past. Location based routing service is active business application in which the position information of moving objects is applied efficiently. This service includes the trajectory of past positions, the real-time tracing of present position of special moving objects, and the shortest and optimized paths combined with map information. In this paper, we describes the location based routing services is extend in distributed web GIS environment. Web GIS service systems provide the various GIS services of analyzing and displaying the spatial data with friendly user - interface. That is, we propose the efficient architecture and technologies for servicing the location based routing services in distributed web GIS environment. The position of moving objects is acquired by GPS (Global Positioning System) and converted the coordinate of real world by map matching with geometric information. We suppose the swapping method between main memory and storages to access the quite a number of moving objects. And, the result of location based routing services is wrapped the web-styled data format. We design the schema based on the GML. We design these services as components were developed in object-oriented computing environment, and provide the interoperability, language-independent, easy developing environment as well as re - usability.

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A Field Tracer Experiment by Using a Radioisotope near the Offshore (동위원소를 이용한 연안역 현장실험)

  • Kim, Ki Chul;Park, Geon Hyeong;Lee, Jin Yong;Jung, Sung Hee;Min, Byung Il;Suh, Kyung Suk
    • Journal of Radiation Industry
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    • v.6 no.1
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    • pp.41-47
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    • 2012
  • A field tracer experiment using a radioisotope was conducted to analyze the transport and dispersion characteristics of pollutants in the coastal area near a Wolsung. A rod float including GPS was released to track the paths of radioisotope. NaI detector was installed to measure the released radioisotope from the boat, and measurements were performed with the real time. The measured tracer data by a field experiment can be used as the basic data for understanding the transport characteristics of pollutants and verifying numerical models near the offshore.

Morphological Characteristics of Forested Coastal Dune Areas Using Direct Topographic Surveys: A Case Study in Dasari, Chungnam (해안림 내부의 지형측량을 통한 충남 다사리 해안사구의 형태적 특징)

  • Choi, Kwang Hee;Kim, Jang soo;Kong, Hak-Yang
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.1
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    • pp.1-12
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    • 2017
  • Planting trees is a very common practice in the coastal dunefields of South Korea as a way to stabilize dune landscapes and protect inland residential areas from strong winds and blown sands. On the other hand, disturbing the original foredune environment may deteriorate the ability of coastal landsto recover from coastal erosion after storms, causing a retreat of coastline. However, there is little information of this sort on the surface of forested dunefields. Airborne LiDAR or drone-based mapping is not easily applicable in such areas. In this study, we developed a digital terrain model of Dasari dunefields, Chungnam Province, based on direct topographic surveys with real-time kinematic GPS and total stations. We also analyzed previous two aerial photographs taken in 1947 and 1966, in order to detect an older landforms of the dunefields. Results suggested that there have been little changes in geomorphology of the Dasari dunefields for the last 50 years, despite continued tree plantings. Today, there are remains of U-shaped structures such as blowouts and parabolic dunes in the dunefields.

Development of monocular video deflectometer based on inclination sensors

  • Wang, Shuo;Zhang, Shuiqiang;Li, Xiaodong;Zou, Yu;Zhang, Dongsheng
    • Smart Structures and Systems
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    • v.24 no.5
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    • pp.607-616
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    • 2019
  • The video deflectometer based on digital image correlation is a non-contacting optical measurement method which has become a useful tool for characterization of the vertical deflections of large structures. In this study, a novel imaging model has been established which considers the variations of pitch angles in the full image. The new model allows deflection measurement at a wide working distance with high accuracy. A monocular video deflectometer has been accordingly developed with an inclination sensor, which facilitates dynamic determination of the orientations and rotation of the optical axis of the camera. This layout has advantages over the video deflectometers based on theodolites with respect to convenience. Experiments have been presented to show the accuracy of the new imaging model and the performance of the monocular video deflectometer in outdoor applications. Finally, this equipment has been applied to the measurement of the vertical deflection of Yingwuzhou Yangtze River Bridge in real time at a distance of hundreds of meters. The results show good agreement with the embedded GPS outputs.