• Communications of the Korean Mathematical Society
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• v.24 no.3
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• pp.381-393
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• 2009

Strong convergence theorems on viscosity approximation methods for finding a common zero of a finite family accretive operators are established in a reflexive and strictly Banach space having a uniformly G$\hat{a}$teaux differentiable norm. The main theorems supplement the recent corresponding results of Wong et al. [29] and Zegeye and Shahzad [32] to the viscosity method together with different control conditions. Our results also improve the corresponding results of [9, 16, 18, 19, 25] for finite nonexpansive mappings to the case of finite pseudocontractive mappings.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.245-254
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• 2008

Recently, many vision-based navigation methods have been introduced as an intelligent robot application. However, many of these methods mainly focus on finding an image in the database corresponding to a query image. Thus, if the environment changes, for example, objects moving in the environment, a robot is unlikely to find consistent corresponding points with one of the database images. To solve these problems, we propose a novel navigation strategy which uses fast motion estimation and a practical scene recognition scheme preparing the kidnapping problem, which is defined as the problem of re-localizing a mobile robot after it is undergone an unknown motion or visual occlusion. This algorithm is based on motion estimation by a camera to plan the next movement of a robot and an efficient outlier rejection algorithm for scene recognition. Experimental results demonstrate the capability of the vision-based autonomous navigation against dynamic environments.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1139-1143
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• 1991

Using industrial robots and sensors, we developed an inline car body inspection system which proposes high flexibility and sufficient accuracy. Car Body Inspection(CBI) cell consists of two industrial robots, two corresponding carriages, camera vision system, a process computer with multi-tasking ability and several LDS's. As industrial robots guarantee sufficient repeatabilities, the CBI cell adopts the concept of relative measurement instead of that of absolute measurement. By comparing the actual measured data with reference data, the dimensional errors of the corresponding points can be calculated. The length of the robot arms changes according to ambient temperature and it affects the measuring accuracy. To compensate this error, a robot arm calibration process was realized. By measuring a reference jig, the differential changes of the robot arms due to temperature fluctuation can be calculated and compensated.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.183-186
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• 2003

A vision sensor should be calibrated prior to infer a Euclidian shape reconstruction. A point to point calibration. also referred to as a hard calibration, estimates calibration parameters by means of a set of 3D to 2D point pairs. We proposed a new method for determining a set of 3D to 2D pairs for the structured light hard calibration. It is simply determined based on epipolar geometry between camera image plane and projector plane, and a projector calibrating grid pattern. The projector calibration is divided two stages; world 3D data acquisition Stage and corresponding 2D data acquisition stage. After 3D data points are derived using cross ratio, corresponding 2D point in the projector plane can be determined by the fundamental matrix and horizontal grid ID of a projector calibrating pattern. Euclidian reconstruction can be achieved by linear triangulation. and experimental results from simulation are presented.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.6
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• pp.501-508
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• 2015

Lately, much research on hull plate forming has been successful in improving productivity of the forming process. Those researches include forming methods, forming information, and automation. After forming each plate, the fabricated surface is compared with the corresponding designed surface. Two sets of data from the designed and fabricated surfaces are matched in order to complete the forming process. However, only a few papers deals with comparison of two surfaces. This paper presents a new matching method based on the bounding volume hierarchy (BVH). By comparing the conventional method, this new approach using BVH shows not only good agreement but also better advantages.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.5
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• pp.383-389
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• 2000

This paper presents a stereo camera system that provides a Pair of stereo images using a Biprism. The equivalent of a stereo Pair of images is formed as the left and right halves of a single CCD image. The system is therefore cheap and extremely easy to calibrate since it requires only one CCD camera. An additional advantage of the geometrical set-up is that corresponding features lie on the same scanline automatically, The single camera and Biprism have led to a simple stereo system for which correspondence is very easy and which is accurate for nearby objects in a small field of view. Since we use only a single lens, calibration of the system is greatly simplified. Given the parameters in the Biprism-stereo camera system, we can reconstruct the 3-D structure using only the disparity between the corresponding points.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.342-348
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• 1998

The purpose of this paper is to extract fast DEM (Digital Elevation Model) using satellite images. DEM extraction consists of three parts. First part is the modeling of satellite position and attitude, second part is the matching of two images to find corresponding poults of them and third part is to calculate the elevation of each point by using the result of the first and second part. The position and attitude modeling of satellite is processed by using GCPs. A area based matching method is used to find corresponding points between the stereo satellite images. In the DEM generation system, this procedure holds most of a processing time, therefore a new fast matching algorithm is proposed to reduce the time for matching. The elevation of each point is calculated using the exterior orientation obtained from modeling and disparity from matching. In this paper, the SPOT satellite images, level IA 6000 $\times$6000 panchromatic images are used to extract DEM. The experiment result shows the possibility of fast DEM. extraction with the satellite images.

• Journal of Convergence Society for SMB
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• v.5 no.1
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• pp.19-23
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• 2015

Distributed Denial of Service attack is a form of denial of service attacks, the attacker to attack a place in a number of points of attack by a wide variety of forms over the network to perform a service on a point attack . Do not use a specific server or client attempts to make a connection to many services available that prevents this attack and so normally used . Corresponding methods of DDoS attacks has a corresponding managerial aspects and technical aspects of the proposed two.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.1
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• pp.11-24
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• 2017

The present work focuses multi-objective optimization of blade sweep for a Wells turbine. The blade-sweep parameters at the mid and the tip sections are selected as design variables. The peak-torque coefficient and the corresponding efficiency are the objective functions, which are maximized. The numerical analysis has been carried out by solving 3D RANS equations based on k-w SST turbulence model. Nine design points are selected within a design space and the simulations are run. Based on the computational results, surrogate-based weighted average models are constructed and the population based multi-objective evolutionary algorithm gave Pareto optimal solutions. The peak-torque coefficient and the corresponding efficiency are enhanced, and the results are analysed using CFD simulations. Two extreme designs in the Pareto solutions show that the peak-torque-coefficient is increased by 28.28% and the corresponding efficiency is decreased by 13.5%. A detailed flow analysis shows the separation phenomena change the turbine performance.

• Korean Journal of Remote Sensing
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• v.30 no.6
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• pp.787-795
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• 2014

This paper presents an image registration using Triangulation-based Local Transformation (TLT) applied to the remaining matched points after elimination of the matched points with gross error. The corners extracted using geometric mean-based corner detector are matched using Pearson's correlation coefficient and then accepted as initial matched points only when they satisfy the Left-Right Consistency (LRC) check. We finally accept the remaining matched points whose RANdom SAmple Consensus (RANSAC)-based global transformation (RGT) errors are smaller than a predefined outlier threshold. After Delaunay triangulated irregular networks (TINs) are created using the final matched points on reference and sensed images, respectively, affine transformation is applied to every corresponding triangle and then all the inner pixels of the triangles on the sensed image are transformed to the reference image coordinate. The proposed algorithm was tested using KOMPSAT-2 images and the results showed higher image registration accuracy than the RANSAC-based global transformation.