• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.347-352
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• 2003

This study attempts to develop the management and control system of water pipe on the footing of database builded by the research on the pipe of water supply equipped over 48.809km within district of Hamyang-up by Hamyang-Gun, and to apply it to the work of self-governing body. And, since the structure and equipment of facilities of underground water supply pipe ate so complex, the maintenance and management of function of facilities are needed for long-term. This study has the purpose to build the database per self-governing body which can be connected with the future NGIS project, and to promote the efficiency of management and control of facilities and equipment.

• Journal of the Korea Society of Computer and Information
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• v.10 no.2 s.34
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• pp.179-186
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• 2005

This study is to develop PDA_based surveying mapping system. This object is achieved by developing wireless communication module of PDA which is adaptable to Total Station and GPS. and contents for its usage. This system will be efficiently used to surveying parts of spatial location information for real time mapping and improving the modification of survey data.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.539-544
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• 2004

In this study, locational information data acquisited by using the side scan sonar which is more precise than traditional submarine terrain' survey equipment. And the result of exploration through the object area(the East sea), accurate submarine terrain could be deciphered by sounded image. Also, in the future, side scan sonar's application will be maximized for the submarine terrain's sediment investigation to design or construction of ocean facilities.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1525-1532
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• 2010

Modern surveying techniques have been progressed to get the absolute position of a single coordinate system at any point on the earth with the advent of the Global Navigation Satellite System and One-stop digital equipment. In addition, as the speed of the railway has been increasingly faster, in determining the location of major facilities including the center of tracks, it is required to the sophisticated precision. The surveying of railway construction has applied the technical supports and procedures in accordance with the current requirements. In this study, the applicable guidelines of surveying on practical issues and alternatives would be examined, analyzed, and presented by using the empirical data of pilot areas in the process of design, construction, and the maintenance of railway.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.2
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• pp.75-80
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• 2017

Recently, there has been growing interest in spatial data that combines information and communication technology with smart cities. The high-precision LiDAR (Light Dectection and Ranging) equipment is mainly used to collect three-dimensional spatial data, and the acquired data is also used to model geographic features and to manage plant construction and cultural heritages which require precision. The LiDAR equipment can collect precise data, but also has limitations because they are expensive and take long time to collect data. On the other hand, in the field of computer vision, research is being conducted on the methods of acquiring image data and performing 3D reconstruction based on image data without expensive equipment. Thus, precise 3D spatial data can be constructed efficiently by collecting and processing image data using CCTVs which are installed as infrastructure facilities in smart cities. However, this method can have an accuracy problem compared to the existing equipment. In this study, experiments were conducted and the results were analyzed to increase the number of extracted matching points by applying the feature-based method and the area-based method in order to improve the precision of 3D spatial data built with image data acquired from stereo CCTVs. For techniques to extract matching points, SIFT algorithm and PATCH algorithm were used. If precise 3D reconstruction is possible using the image data from stereo CCTVs, it will be possible to collect 3D spatial data with low-cost equipment and to collect and build data in real time because image data can be easily acquired through the Web from smart-phones and drones.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.83-89
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• 2004

The electronic distance measurement instrument, first introduced in the 1950s has, since those early days, undergone continual refinement. Rapid advances in related technologies have provided lighter, smaller and more precise equipment. Understanding for the principle, the standardized observation technique and the precision of EDM instrument is mostly important to improve the quality and the reliability of by-product in the field of engineering and industrial surveying. Simple and accurate calibration is regularly and periodically necessary to maintenance the precision of EDM instrument. This paper describes the calculated example of zero error and scale error as a correction of EDM by applying the least square method to baseline observations. Here we deals also with the testing criteria for precision instrument testing according to different types of EDM instruments.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.281-284
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• 2010

Recently the development of digital based measurement sensor with which a variety of surveying equipment and methods are being developed. In the field of aerial mapping using GPS, INS and Digital Camera instead of Film based Camera. In case of aerial photogrammetry for mapping, it is effective on wide area. But it is ineffective on narrow area. Therefore, the research experimented that used LiDAR sensor based mobile mapping systems for modify and update about region of Suwon and Yeouido. From these results a possibility and an effectiveness analyzed and evaluated LiDAR sensor based mobile mapping systems.

• Journal of Korean Port Research
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• v.15 no.1
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• pp.75-85
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• 2001

Accuracy of dredging processes depends on the types of equipment used, the sediments encountered, whether the work to be performed is new or maintenance dredging, pre- and post-hydrographic surveying and so forth. Among those, position surveying accuracy which is directly determined by the control of the dredge's position and depth surveying accuracy being surveyed at the dredging point during dredging work are important factors. The purpose of this study is to develop 'Dredge Management System'for Grab dredge which is composed of 4 sub-system using LADGPS for dredge position determining system and dredging point determining system, tide gauge system and optical sensor for depth determining system and GIS and ENC for total management system. This system is installed on the grab dredge 'EUNJIN G-18'and applied to anchorage dredging work. at Pohang Harbor. The results revealed that this system is easy to operate, achieves good accuracy with only 45cm unevenness, reduces working period by 22 percent and saves cost 16.6 percent.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.73-80
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• 2020

The OECD surveys the questionnaire on the background of ICT every three years since 2003. In this study, we compare and analyze the changes in ICT accessibility and ICT usability of Korean students in 2015 and 2018 using the ICT background data of OECD PISA. ICT accessibility refers to the degree of access to ICT equipment at school or at home. There are 10 items of accessibility surveys at schools used by PISA, and 11 items at home. ICT usability refers to how much ICT equipment is used at or outside of school for learning or non-learning purposes. There are ten items for surveying usability at school, and twenty-four items for surveying usability outside of school. In the analysis of this study, the arithmetic mean of the items is used. As a result, Korean students' accessibility at school improved from 25.48% in 2015 to 40.40% in 2018, and from the lowest group in 2015 to below-average group in 2018. In terms of students' usability at school, we analyzed the percentage of students who use the ICT equipment 'almost every day' and the students who use it 'everyday'. Both 2015 and 2018 are among the lowest. Accessibility at home is higher in 2018 than in 2015, and belongs to the average group of OECD countries in 2018. ICT Usability for learning purposes outside of school is the lowest group in both 2015 and 2018. ICT Usability outside of school for non-learning purposes is in the average group of OECD countries. As a result of this study, we can see that Korea's digital literacy education is weak compared to other OECD countries. Prior to education about the Fourth Industrial Revolution, investment in digital literacy education is needed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.5
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• pp.253-263
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• 2021

Traffic data collected using advanced equipment are highly valuable for traffic planning and efficient road operation. However, there is a problem regarding the reliability of the analysis results due to equipment defects, errors in the data aggregation process, and missing data. Unlike other detectors installed for each vehicle lane, radar detectors can yield different error types because they detect all traffic volume in multilane two-way roads via a single installation external to the roadway. For the traffic data of a radar detector to be representative of reliable data, the error factors of the radar detector must be analyzed. This study presents a field survey of variables that may cause errors in traffic volume collection by targeting the points where radar detectors are installed. Video traffic data are used to determine the errors in traffic measured by a radar detector. This study establishes three types of radar detector traffic errors, i.e., artificial, mechanical, and complex errors. Among these types, it is difficult to determine the cause of the errors due to several complex factors. To solve this problem, this study developed a radar detector traffic volume error analysis model using a multiple linear regression model. The results indicate that the characteristics of the detector, road facilities, geometry, and other traffic environment factors affect errors in traffic volume detection.