• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.1
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• pp.1-14
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• 2022

In order to conduct rapid, accurate and safe surveying at the excavation site, In this study, the possibility of underground facility survey using drones and the expected effect of 3D visualization were obtained as follows. Phantom4Pro 20MP drones have a 30m flight altitude and a redundant 85% flight plan, securing a GSD (Ground Sampling Distance) value of 0.85mm and 4points of GCP (Groud Control Point)and 2points of check point were calculated, and 7.3mm of ground control point and 11mm of check point were obtained. The importance of GCP was confirmed when measured with low-cost drones. If there is no ground reference point, the error range of X value is derived from -81.2 cm to +90.0 cm, and the error range of Y value is +6.8 cm to 155.9 cm. This study classifies point cloud data using the Pix4D program. I'm sorting underground facility data and road pavement data, and visualized 3D data of road and underground facilities of actual model through overlapping process. Overlaid point cloud data can be used to check the location and depth of the place you want through the Open Source program CloudCompare. This study will become a new paradigm of underground facility surveying.

• Advances in concrete construction
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• v.16 no.2
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• pp.79-89
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• 2023

The occurrence of unexpected horizontal offset in the instrument or target will result in accumulated horizontal deviation in segment alignment with traditional short-line match method. A geometry control method, the four-point method, is developed for precast segmental bridges to avoid the influences of unexpected horizontal offset. The concept of the four-point method is elucidated. Furthermore, the detailed instruments and instructions are introduced. Finally, the four-point method is validated through a practical engineering application. According to the survey data, after short-line match precast construction, the vertical deviations on both sides vary between -5 mm and 5 mm in almost all segments, and the horizontal deviations vary between -4 mm and 4 mm in all segments. Without on-site adjustment, the maximum vertical and horizontal closure gaps are 12.3 and 26.1 mm, respectively. The four-point method is suggested to alleviate the issues associated with relatively poor soil conditions in casting yard.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.687-696
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• 2023

In recent construction sites, digital maps obtained through drone photogrammetry have garnered increasing attention as indispensable tools for effective construction site management. the strategic placement of Ground Control Points (GCPs) is crucial in drone photogrammetry. Nevertheless, the manual labor and time-intensive nature of GCP surveying pose significant challenges. The purpose of this study is to design the concept of automated GCPs survey technology for enhancing drone photogrammetry efficiency in construction sites. As a result, the productivity of the automated method was analyzed as 118,894.7㎡/hr. It is over 25% productivity improvement compared to traditional methods. In future studies, economic analysis of automated methods should be studied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3478-3485
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• 2011

This study utilized the GPS data of the stations of triangulation of Changwon-si, Gyeongsangnam-do to conduct comprehensive analysis on tolerance level and regional characteristics. Based on this analysis, it was attempted to seek the method to derive more accurate result when further performing cadastral control point surveying for cadastral detail surveying. For the stations of triangulation installed at time of the land survey project, the study result showed that the most results of the stations of triangulation are stable if they were not moved naturally or artificially by themselves. Therefore, it was concluded that the stations of triangulation installed at the time of the land survey project should be preemptively selected for use of the given points when making decision of result of cadastral control point surveying. In addition, if the result of the cadastral control point surveying is made decision based on the stations of triangulation presented as the stable result in this study result, it seems that the same surveying result will be maintained and managed at all time, even if they are going to be further reinstalled due to loss of them.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.507-512
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• 2004

Research that establish new cadastral survey model that use GPS to introduce GPS observation technique in cadastral survey and research that develop connection technologies are gone abuzz. The purpose of this research is to keep in step in such trend and grasp present condition and performance of surveying connection to common use GPS data processing software, and analyze data processing algorithm, and develop suitable GPS data processing software in our real condition regarding GPS data processing and result of control point calculation. This research studies analysis common use software and error occurrence by data processing method that college and company have. Also, It analyzes algorithm that is applied to existing GPS data processing software. After that we study algorithm that is most suitable with cadastral survey and then develop cadastral survey calculation software for new cadastral control points

• Korean Journal of Geomatics
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• v.3 no.1
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• pp.73-79
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• 2003

To manage national territory and cadastral data efficiently, accuracy and cost-efficiency in cadastral boundary surveying is inevitable. The efficient management of cadastral data is a very important element in national land management. Survey techniques are being introduced. Recently, improvements in survey techniques have been made with the development of satellite surveying, Allowing accurate and fast surveys. If we can calculate the output accurately in real-time in survey fields, it will open a new method in cadastral detail surveying. According to the classification on Law of cadastral surveying, Cadastral surveying can be divided into cadastral control point surveying and cadastral detail surveying. The control point survey can be divided into cadastral triangulation surveying and cadastral traverse surveying. The detailed survey is usually perform by plane surveying. Among these, cadastral detail surveying will be reviewed in this study. In this study, the combination of the satellites, such as US managed GPS and Russian managed GLONASS was used. In the satellite survey in downtown, data interruption symptoms arose(according to the mask angle of the satellite). Therefore; we combined the satellites to get date more accurately. A block of Haewoondae New City in Busan, Korea, which has Numerical Cadastral Law was selected as the sample area for this study. Block II and III are surrounded by high rise apartments. One side of Block I and IV is level ground and the other side is full of high rise apartments. Especially, Block II is surrounded by high rise apartment houses with 20 meters width. In the results of the study Block II did not satisfy the allowable precision, while Block I, II and IV satisfied the allowable precision of the enforcement regulations of Cadastral Law. Therefore, it is judged that the traditionally used Total Station method should be used for supplementary survey on Block II, in stead.

• Journal of the Korean association of regional geographers
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• v.15 no.1
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• pp.161-178
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• 2009

The introduction of a world geodetic system for cadastral survey will be started the enactment of the law on survey, hydro-graphical examination and cadastre. However, the cadastral control points are not homogeneous and correspond with national control points because of various reasons. To cope with this problem, the 1,600 high accurate control points, which can be interlocked with national GPS control points, has selected from existing 20,000 cadastral control points. These selected control points were calculated as an accurate world geodetic system and it makes a homogeneous cadastral survey network. Through these measures, for the future carrying out national project, this study will be effectively contributed to establish the cadastral infrastructures for the Korea cadastral reform project.

• Korean Journal of Acupuncture
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• v.25 no.2
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• pp.71-85
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• 2008

Objective : Acupuncture, one of the Oriental medical treatment techniques in East Asia, is growing in popularity all over the world. Based on bibliographical and clinical data, the depth of needling, i.e. superficial or deep needling, has been considered to be a variable as potential modifiers of needling effects, such as localization, manipulation of the needle, or elicitation of DeQi. The purpose of this review is to summarize clinical trials using minimal acupuncture and to evaluate its appropriateness as a control. Methods : A survey of computerized literature searches for randomized controlled trials using minimal acupuncture revealed that a total of 10 studies were published until April 2008. Results : Results obtained from clinical trials showed that acupuncture were more effective than minimal acupuncture in 3 out of 10 trials, while others were no more effective than control. However, minimal acupuncture might neither be a inert placebo nor be indiscriminable. Conclusion : Minimal acupuncture as 'placebo' controls seems misleading and scientifically unacceptable.

• Spatial Information Research
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• v.15 no.3
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• pp.237-249
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• 2007

There are about 22,000 national control points throughout this nation. However, in order to identify the location data of a national control point, a control point result table is needed. And although the control points are important national facilities, due to the fact that these points located at remote areas such as on top of mountains, the facilities are being maintained via on-site inspection without any protections around them. In this research, by taking the locations where the control points are placed into consideration, a specialized RFID tags that can be attached to the national control point's marker has been developed, and CDMA-ready PDA based mobile Web System and national control point control system are developed as well. With help of these systems, control point data can be checked at the seen, and national control point maintenance personnel can find out about maintenance status and keep track of usage record. When these systems are taken into effect, access to the national control point data becomes easy, fast response to the change in data can be possible, and management efficiency will go up. When the Ubiquitous society becomes reality, the importance of location information will be high. Therefore, national control points using above mentioned RFID tags will not only be useful to the control point users and maintenance personnels such as professional land surveyors, but also useful when providing location based services to people, and it will become an important national infrastructure in terms of providing absolute location information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.1
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• pp.153-160
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• 2010

It is necessary to determine accurate 3-dimensional coordinates of the building corner points that could be control or check points in order to verify the accuracy of 3D digital maps in the near future. The usual process of obtaining the coordinates of the building corner points is to set up the ground control points with a GPS and then to practice terrestrial survey such as distance or angle measurements. However, since an error in the ground control points can be propagated through the terrestrial survey into the final coordinates of the buildings, accurately should be considered as much as possible. The actual effect of the GPS-derived ground control point error on the estimates of the unknowns through the terrestrial survey is mathematically analyzed, and the simulation data is tested numerically. The error of the ground control points is tested in the cases of 1-4 cm for the horizontal components and 2-8 cm for the vertical component. The vertical component error is assigned twice the horizontal ones because of the characteristics of the GPS survey. The distance measurement is assumed for convenience and the precision of the estimated coordinates of the building corner points is almost linearly increased according to the errors of the ground control points. In addition, the final estimates themselves can vary by the simulated random errors depending on the precision of the survey instrument, but the precision of the estimates is almost independent of survey accuracy.