• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.677-682
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• 2009

According to the revised law of survey, all the geographic information data including 1/1,000 digital topographic maps have to be converted to world geodetic reference system by the end of 2009. National Geographic Information Institute (NGII) formulated the policy to promote the conversion from local geodetic reference system to world geodetic reference system. However, the current conversion rate is lower than planned due to some impeding factors. Therefore, in this paper, those impeding factors are investigated and then efficient conversion strategies are established and provided. The research involves the validation of affine transformation, the determination of critical value for outlier detection and optimal number of common control points for coordinate conversion, and the treatment of old and new control points.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.437-449
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• 2007

This paper deals with issues of GPS network adjustment for the purpose of determining the $3^{rd}$ order national geodetic control points based on the Korean Geodetic Datum which has newly adopted in the country since early 2003. After examining and arranging all the observations, GPS baseline analyses were performed to estimate baseline vectors between two control points. All the observations were divided into 17 block networks in order to accelerate the adjustment efficiency. After applying a minimally constrained adjustment technique to each of the block networks for the sake of detecting outliers and examining network precision, over constrained adjustments by fixing all of the $2^{nd}$ order control points within the block network were carried out to derive final coordinate sets. The final solutions indicated that the accuracy of the adjusted coordinates was better than 1cm and 2cm in the horizontal and vertical component, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.3
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• pp.311-321
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• 2009

The Nation Geodetic Reference System which presents a consistent location standard used in creating a map or developing national land is defined and managed by the law in a nation. Each nation had used its own geodetic system created by astronomical surveying until recently, when Geodetic Reference System(World Geodetic Reference System) has been developed and used to progress in space and satellite geodetic technologies. Korea also amended its geodetic law in December 2001, converting its national geodetic system whose reference an oval figure is Bessel ellipsoid into the World Geodetic Reference System which uses GRS80 ellipsoid as reference ellipsoid. Accordingly, the National Geography Information Institute improved law and systems related to the change for the effective conversion from its national geodetic system into the World Geodetic Reference System. In addition National geographic information institute of the results of various studies is drawn to the World Geodetic Reference System for switching technology-met some of the institutional foundation Despite of accordance with formalities, National geographic information institute, Ministry of Land, Transport and Maritime Affairs and some local government of the World Geodetic Reference System, and local government has or has not spread in public institutions. Therefore, in order to promote the switch to the World Geodetic Reference System, it is required to analyze current technical and institutional problems and obstacles of the switch to the World Geodetic Reference System and to present the resolutions and to establish policy to achieve them. Accordingly, for the promotion of the switch to the World Geodetic Reference System, this study analyzed the results of previous studies, the current state of the switch to the World Geodetic Reference System and the problems of the switch, and then offered technological and institutional supplements. Furthermore, it standardized the subject and type of the conversion, defined the scope of the tasks of the National Geographic Information Institute and its related organizations, and presented the policy direction for the overall use of the World Geodetic Reference System by 2010.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.3 no.2
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• pp.11-17
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• 1985

In the three dimensional Cartesian Coordinate System such as the satellite geodesy the relationship of the geoid and the reference ellipsoid must be known. Therefore, the determination of geoidal heights is regarded as one of the most important problem in geodesy. This paper deals with determination of astro-geodetic geoid by the spherical surface polynomials interpolation method. The data that astronomical deflection of the vertical was published by National Geography Institute is applied. The map of geoidal heights is drawn out. This shows that Tokyo Datum have influenced on Korea.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.309-313
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• 2014

This research was conducted to establish recommendable side shoot management methods in the growth and yield of tomato in winter. A cherry tomato, $^{\circ}{\times}Unicorn^{\circ}{\pm}$ (Monsanto Korea, Korea) was cultivated in coconut coir in the form of bag as substrate. There were four treatments related to side shoot removal methods; 1) To remove all side shoots and also each one of three leaves which gives shade to each cluster attached below (UP-FL), 2) To remove all side shoots and also each one of three leaves which gives shade to each cluster only with fruit attached below (UP-FR), 3) To remove all side shoots (AS-All), and 4) To remain two leaves of each side shoot coming from right below each cluster (AS-Part). The number of malformed leaves were more in UP-FL, UP-FR, AS-All, and AS-Part in descending order, which showed the severe the removal of leaves the more the malformed leaves. The malformed leaves were diminished after the development stage the second or third cluster bloomed. The yields until fifth cluster were not different among the treatments. Therefore removal of side shoots and leaves recommends not to be done severely in early growth stage when tomato plants are cultivated in winter.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.spc4_2
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• pp.401-412
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• 2014

This study is purposed on showing an effective process for coordinate transformation of cadastral maps, based on the local datum, in the World Geodetic System (WGS) for Cadastral Reform Project (CRP). The process follows three steps: coordinate adjustment, datum transformation and distortion modeling. The first procedure is that point coordinates on local datum has to be adjusted by those GPS observed point-to-point distances, using trilateration. Secondly, the adjusted coordinates need to be transformed to WGS by applying the Affine model, while the verification of the methodology is implemented under numerical experiments. To conduct this procedure, 195 points in the same coordinate origins in Seoul and 61 points in several different origins in Incheon are used in the estimation. As a result, there are less than 2cm coordinate differences between transformed coordinates and measured ones at everywhere. Also, it is remarkable that the transformation does not depend on either of the particular common points or the sizes of computed region. Therefore, this suggested methodology is expected to easily provide identifications and corrections for points-deviations for improved quality of the cadastral map by distortion modeling through CRP.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.2
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• pp.141-146
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• 1982

In the vine training methods, main vine training yield was 36% higher than the non-training. Main vine training date was studied for increasing cone yield in hops. Training was done four different dates from May 14 to May 29 including non-training as a check. Earlier training increased cone yield from 12 to 43% due to more beared branches per plant, longer branch length caused by accelerating the branch growth, and an increased of number of cone per beared branch and total cone number.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.2 no.2
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• pp.21-28
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• 1984

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.561-571
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• 2020

Seven techniques widely used in the geodetic transformations have been reviewed and compared to figure out their theoretical characteristics. A series of numerical tests were performed about four data sets. This was followed by result analyses in terms of transformation residuals and accuracies together with some hypothesis testings based on the student-t distribution to confirm the statistical significance of the techniques. In the case of the transformation between the geodetic frames implemented in the same system, no statistical significance was revealed in the results of the 3D transformation techniques, even if the testing area becomes large as the Asia-Oceania continent. Among the 2D transformations, it was possible for the NTv2 grid modeling technique to deliver improved transformation accuracy. Finally, it was possible from the results analyzed in this study to propose the Helmert transformation to geodetic control points and the NTv2 technique to the 2D spatial data transformation of the geodetic systems.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.5 no.1
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• pp.66-72
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• 1987

It is well known that a triangulateration net is superior to a trilateration net or triangulation net in a same configuration. In general, to explain this nature is not easy because the large residuals and reference variance are revealed in the adjustment of a heterogeneous network. In this paper the precision and the reliability of network are discussed, and the considerations of simultaneous adjustment are covered A practical example shows that the concept and criteria of reliability give better estimate than the precision in heterogeneous network.