• Journal of the Korean Society for Precision Engineering
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• v.14 no.11
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• pp.118-125
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• 1997

Non-contacting optical microscopes are increasingly used in recent industrial applications of probes for coordinate measuring machines. They have been found more efficient than conventional touch trigger porbes with ball tips especially in inspecting small-sized objects. There are two major factors affecting measuring accuracy: (1) geometric relations between coordinate systems, (2) magnification ratios of a microscope. In order to determine the magnification ratios exactly, optical imaging of edge was theroretically analyzed and practically adopted to image processing for edge detection. In addition, this paper proposes a geometric calibration method to obtain exact coordinates of measured points from the relations between the machine coordinate system and the image. In the method, the error according to the squareness between the machine axises was also removed. The method was practically adopted to a real coordinate measuring machine. An ultraprecision measurement of 0.2 um uncertainty can be practically achieved.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.175-181
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• 2010

This paper presents the dynamic analysis method for estimating the performance of flat-type blades in wiper systems. The blade has nonlinear characteristics since the rubber is a hyper-elastic material. Thus, modal coordinate and absolute nodal coordinate formulations were used to describe the dynamic characteristic of the blade. The blade was structurally analyzed to find the bending characteristics of the cross section of the blade. According to the analysis results, the blade section is divided into three deformation bodies: rigid, small, and large. For the small deformation body, the modal coordinate formulation is used, while the absolute nodal coordinate formulation is used for the large deformation body. To verify the dynamic analysis result, an experiment was performed. The simulation and experiment results were compared to verify the flexible multi-body dynamic model.

• Journal of Digital Convergence
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• v.18 no.2
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• pp.73-81
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• 2020

The purpose of this study is to analyze the current status of expected cadastral coordinate maps by type of district boundary surveying and the problems of non-coincidence with the surrounding land parcels, and to suggest ways to improve them in the future. Currently, the expected cadastral coordinate maps are drawn using various methods such as reference point adjust adjustment, reference point adjust adjustment and present condition, reference point and present condition. As a result, there was a problem of non-coincidence such as overlapping or blanking in expected cadastral coordinate maps for cadastral confirmation surveying and surrounding individual parcels. In addition, detailed unified standards for minimizing the occurrence of non-coincidence problems are lacking. In order to improve the problems analyzed, the study suggested the acquisition and management of digital coordinates for the parcels around the district boundary, the preparation and dissemination of cadastral surveying results determination standard manual for the preparation of expected cadastral coordinate maps, and the preparation of educational programs for cadastral surveying results determination.

• Geophysics and Geophysical Exploration
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• v.16 no.2
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• pp.91-96
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• 2013

This study proposes a method to correct inclination of instrument during exploration with a biaxial clinometer and GNSS compass. In 3-component magnetometry, measured vectors are ordinarily described in randomly inclined observation coordinate system due to movement, vibration, and shaking of instrument. Therefore, rotation angles of observation plane are needed to transform it into geodetic coordinate system. In this study, we measured inclination angles of observation plane by using 2-axis clinometer and GNSS compass, and derived proper parameters for rotational transform from them. We applied the conversion method to on-board 3-component magnetometry, and then transformed raw data into proper values on geodetic coordinate system.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.1-8
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• 2007

In this paper, research on joint optimization of the image spatial registration and the exposure compensation is conducted. The exposure compensation is performed in a frame work of the intensity compensation based on the polynomial approximation of the relationship between images. This compensation is jointly combined with the registration problem employing the Gauss-Newton nonlinear optimization method. In this paper, to perform for a simple and stable optimization, the block-coordinate method is combined with the Gauss-Newton optimization and extensively compared with the traditional approaches. Furthermore, regression analysis is considered in the compensation part for a better stable performance. By combining the block-coordinate method with the Gauss-Newton optimization, we can obtain a compatible performance reducing the computational complexity and stabilizing the performance. In the numerical result for a particular image, we obtain a satisfactory result for 10 repeats of the iteration, which implies a 50% reduction of the computational complexity. The error is also further reduced by 1.5dB compared to the ordinary method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.4
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• pp.20-28
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• 2008

We propose a radial image processing method in a discrete polar coordinate system based on L1-norm. For this purpose, we first verified that the polar coordinate based on L2-norm can not exist in discrete system and then develop a method converting the Cartesian coordinate to the discrete polar coordinate. We apply the proposed method to smooth mass images of breast tissue and to detect the boundaries of extremely deformable objects. Compared to the Gaussian smoothing method performed in the Cartesian coordinate system, the proposed method stabilized the image signal while maintaining the overall radial shape of mass images. The proposed boundary detection method can detect shapes with high precision while conventional edge detectors can not accurately detect the shape of deformable objects. We also exploit the method to perform pupil detection and have had good experimental results.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.2
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• pp.117-123
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• 2001

Requiring topographic information of map due to retaining russia map, which needed accuracy analysis of russia map and relation between its and south korea's map. In order to obtain exact location information from the map which has different reference datum. We have to operate coordinate transformation between maps applied different ellipsoid. In this paper, in order to evaluate accuracy between two maps applied different ellipsoid, it has studied theory of map projection and coordinate transformation. Then, select each point which can be recognized on the two maps for accuracy evaluation. After obtaining coordinate values for each point of same area, it is evaluated accuracy each geodetic coordinate and each TM coordinate. As a result of this study, the maps which have different reference datum could be used if the exact origin shift could be obtained and applied.

• Journal of the Korea Society of Computer and Information
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• v.27 no.5
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• pp.157-163
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• 2022

As the online game market grows, the use of game bots is causing the most serious problem for game services. We propose a harvest coordinate analysis model to detect harvesting bots among game bots of the Massively Multiplayer Online Role-Playing Games(MMORPGs) genre. The proposed model analyzes the player's harvesting behavior using the coordinate data. Game bots can obtain in-game goods and items more easily than normal players and are not affected by realistic restrictions such as sleep time and character manipulation fatigue. As a result, there is a difference in harvesting coordinates between normal players and game bots. We divided the coordinate zones and used these coordinate zone differences to distinguish between game bot players and normal players. We created a dataset with NCSoft's AION log and applied it to a random forest model to detect game bots, and as a result, we derived performance with a recall of 0.72 and a precision of 0.92.

• Journal of the Korea Computer Graphics Society
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• v.23 no.3
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• pp.31-38
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• 2017

In this paper, we propose a system which estimates Manhattan coordinate systems for urban scene images using a convolutional neural network (CNN). Estimating the Manhattan coordinate system from an image under the Manhattan world assumption is the basis for solving computer graphics and vision problems such as image adjustment and 3D scene reconstruction. We construct a CNN that estimates Manhattan coordinate systems based on GoogLeNet [1]. To train the CNN, we collect about 155,000 images under the Manhattan world assumption by using the Google Street View APIs and calculate Manhattan coordinate systems using existing calibration methods to generate dataset. In contrast to PoseNet [2] that trains per-scene CNNs, our method learns from images under the Manhattan world assumption and thus estimates Manhattan coordinate systems for new images that have not been learned. Experimental results show that our method estimates Manhattan coordinate systems with the median error of $3.157^{\circ}$ for the Google Street View images of non-trained scenes, as test set. In addition, compared to an existing calibration method [3], the proposed method shows lower intermediate errors for the test set.

• 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.