• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.211-218
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• 2003

The purpose of this study is to analyze the interior orientation, relative orientation, absolute orientation, space intersection, space resection, computing the orientation parameter, 3-dimensional coordinates by using the EXCE for educational purpose.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.1
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• pp.69-83
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• 2020

Signboards are standardized according to national legislation for the safety of pedestrians and disaster prevention in urban areas. Signboards should be installed according to the standard. However, it is not easy to manage the signboards systematically due to the number of signboards that have been installed for a long time and frequently changing stores. In this study, we proposed a methodology for distinguishing signboards that deviated from the standard. To this end, the signboard was photographed using a stereo camera, and then the three-dimensional coordinates of the signboard were determined from the signboard image to calculate the signboard's horizontal and vertical dimensions to determine the signboard's specifications. In order to determine the interior and relative orientation parameters of the stereo camera, an outdoor three-dimensional building was used as the test field. Then, the image coordinates of four vertices of the signboard were extracted from the signboard image taken from about 15m ~ 22m distance using deep learning. After determining the signboard's three-dimensional coordinates by using the interior and relative orientation parameters of the stereo camera and the image coordinates of the four vertices of the signboard, the horizontal and vertical sizes of the signboard were calculated, resulting in an error of about 2.7cm on average. The specifications for the ten flat-type signboards showed that all of the horizontal sizes were compliant with the specifications, but the vertical sizes exceeded about 36.5cm on average. Through this, it was found that maintenance of flat-type signboards is needed overall.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.527-534
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• 2005

Rotation and scale variations make it difficult to solve the problem of shape description and recognition because these variations change the location of points composing the shape. However, some geometric Invariant points and the relations among them are not changed by these variations. Therefore, if points in image space depicted with the r-y coordinates system can be transformed into a new coordinates system that are invariant to rotation and scale, the problem of shape description and recognition becomes easier. This paper presents a shape description method via transformation from the image space into the invariant feature space having two axes: representing relative distance from a centroid and contour segment curvature(CSC). The relative distance describes how far a point departs from the centroid, and the CSC represents the degree of fluctuation in a contour segment. After transformation, mesh features were used to describe the shape mapped onto the feature space. Experimental results show that the proposed method is robust to rotation and scale variations.

• Convergence Security Journal
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• v.6 no.2
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• pp.71-80
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• 2006

Sensor network is made from very small and restrictive-power nodes, and they collect some information of environment like as thermal and tremor, etc. And they transfer the information to each other. Generally, supporting the Security service of sensor network is a difficult work, because the nodes have very small cpu-power and low electronic-power. So, More effective management scheme will needed for the maintenance of stability. In this paper, we propose the location based management scheme with circular coordinates. We were make the with the relative location information from one node to other. The new scheme show more simple and effective result then the other method for key management.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.305-315
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• 2010

This research aims to develop a method to determine the 3D coordinates of an object point from overlapping omni-directional images acquired by a ground mobile mapping system and assess their accuracies. In the proposed method, we first define an individual coordinate system on each sensor and the object space and determine the geometric relationships between the systems. Based on these systems and their relationships, we derive a straight line of the corresponding object point candidates for a point of an omni-directional image, and determine the 3D coordinates of the object point by intersecting a pair of straight lines derived from a pair of matched points. We have compared the object coordinates determined through the proposed method with those measured by GPS and a total station for the accuracy assessment and analysis. According to the experimental results, with the appropriate length of baseline and mutual positions between cameras and objects, we can determine the relative coordinates of the object point with the accuracy of several centimeters. The accuracy of the absolute coordinates is ranged from several centimeters to 1 m due to systematic errors. In the future, we plan to improve the accuracy of absolute coordinates by determining more precisely the relationship between the camera and GPS/INS coordinates and performing the calibration of the omni-directional camera

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.387-393
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• 2015

This study presents a precise relative navigation algorithm using both laser and Global Positioning System (GPS) measurements in real time. The measurement model of the navigation algorithm between two spacecraft is comprised of relative distances measured by laser instruments and single differences of GPS pseudo-range measurements in spherical coordinates. Based on the measurement model, the Extended Kalman Filter (EKF) is applied to smooth the pseudo-range measurements and to obtain the relative navigation solution. While the navigation algorithm using only laser measurements might become inaccurate because of the limited accuracy of spacecraft attitude estimation when the distance between spacecraft is rather large, the proposed approach is able to provide an accurate solution even in such cases by employing the smoothed GPS pseudo-range measurements. Numerical simulations demonstrate that the errors of the proposed algorithm are reduced by more than about 12% compared to those of an algorithm using only laser measurements, as the accuracy of angular measurements is greater than $0.001^{\circ}$ at relative distances greater than 30 km.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.352-360
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• 1997

An inverse dynamic procedure for spatial multibody systems containing flexible bodies is developed in the relative joint coordinate space. Constraint acceleration equations are derived in terms of relative coordinates using the velocity transformation technique. An inverse velocity transformation operator, which transforms the Cartesian velocities to the relative velocities, is derived systematically corresponding to the types of kinematic joints connecting the bodies and the system reference matrix. Using the resulting matrix, the joint reaction forces and moments are analyzed in the Cartesian coordinate space. The formulation is illustrated by means of two numerical examples.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.4
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• pp.80-90
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• 1994

Basic constraint equations derived from orthogonality conditions between a pair of body-fixed vectors and a body-fixed vector or a vector between two bodies are reformulated by using relative coordinate kinematics between two adjacent reference frames. Arithmetic numbers of operations required to compute derivatives of the constraint equations are drastically reduced. A mixed formulation of relative and cartesian coordinates is developed to further simplify derivatives of the constraints. Advantages and disadvantages of the new formulation are discussed. Possible singularity problem of para llelism constraints is resolved by introducing an extra generalized coordinate. Kinematic analysis of a McPherson strut suspension system are carried out to illustrate use and efficiency of the new formulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.11
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• pp.2804-2811
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• 2000

A Nordsick form opf the multirate integration scheme has been proposed for flexible multibody dynamic systems. It is assumed that vibrational modal coordinates in the equations of motion are treated as fast variables, whereas the relative joint coordinates are treated as slow variables. In the multirate integration, the fast variables are integrated with small step-size, and the slow variables are integrated with larger step-size. The proposed multirate integration method is based on the Adams-Bashforth-Moulton predictor-corrector method and implemented in the Nordsieck vector form. The Nordsieck form of multrate integration method provides effective step-size control and at the same time, inherits the efficiency from the Adams integration method. Simulations of a flexible gun and turret system of the military tank have been carried out to show the effectiveness and efficiency of the proposed method.

• 전자공학회논문지 IE
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• v.46 no.1
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• pp.23-30
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• 2009

In this paper, the intelligent vision system for an effective and intelligent path-planning of an industrial AGV system based on stereo camera system is proposed. The depth information and disparity map are detected in the inputting images of a parallel stereo camera. The distance between the industrial AGV system and the obstacle detected and the 2D Path coordinates obtained from the location coordinates, and then the relative distance between the obstacle and the other objects obtained from them. The industrial AGV system move automatically by effective and intelligent path-planning using the obtained 2D path coordinates. From some experiments on AGV system driving with the stereo images, it is analyzed that error ratio between the calculated and measured values of the distance between the objects is found to be very low value of 2.5% on average, respectably.