• The KIPS Transactions:PartB
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• v.13B no.3 s.106
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• pp.239-244
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• 2006

In this paper, we present a snake-based scheme for contour tracking of objects in stereo image sequences. We address the problem by managing the insertion of new points and deletion of unnecessary points to better describe and track the object's boundary. In particular, our method uses more points in highly curved parts of the contour, and fewer points in less curved parts. The proposed algorithm can successfully define the contour of the object, and can track the contour in complex images. Furthermore, we tested our algorithm in the presence of partial object occlusion. Performance of the proposed algorithm has been verified by simulation.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.193-201
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• 1992

A new equivalent curved beam theory is developed for the analysis of the corner part of ship structures, in which effects of distributed loads and asymmetricity with two or three connected parts are considered. Equivalent loads are obtained from equilibrium conditions between the distributed loads and the member forces and moments at the ends of curved beam. And an equivalent curved beam for the asymmetric structure is obtained by superposing the equivalent symmetric parts which have equivalent stiffness. From the sample calculation, it is found that the results of the new equivalent curved beam theory are well agreed with those of finite element method using membrane elements with little computing time and sufficient accuracy.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.5
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• pp.527-535
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• 2015

As a new technical approach, a hydraulic and magnetic clamp device was attempted to realize a magnetic clamp crane system that uses 8 simultaneously actuating individual hydraulic cylinders. Through this approach, a Sr type of ferritic permanent magnet ($SrO{\cdot}6Fe_2O_3$), not the previously employed electro-magnet, was utilized for the purpose of lifting and transporting the heavy weighted and oversized curved steel plates used for manufacturing the ships. This study is aimed at manufacturing and developing the hydraulic magnetic clamp prototype, which is composed of three main parts - the base frame, cylinder joint, and magnet joint - in order to safely transport such curved steel plates. Furthermore, this research was pursued to conduct a performance evaluation as to the prototype manufacture and acquire the planned quantity value and the development purpose items. The most significant item for a performance evaluation was estimated for the magnetic adhesive force (G) and in this process, a ferritic permanent magnet (Sr type) with 3700~4000 G of residual induction (Br) and 2640/2770 Oe of coercive force (Hc) was utilized. In addition, other relevant items such as hoist tension (kN), transportation time (sec), and the applied load (Kgf) exerted on the hydraulic cylinders were also evaluated in order to acquire the optimum quantity value. As a result of the evaluation, the relevant device turned out to be suitable for safely transporting the curved steel plates.

• Composites Research
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• v.13 no.1
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• pp.25-32
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• 2000

In this paper, postbuckling behavior of laminated composite-stringer stiffened-curved panels loaded in local compression is analyzed using the finite element program developed. Postbuckling Analysis is performed in dividing the panel behavior into three basic parts. The eight node degenerated shell element is used in modelling both panel and stiffeners, and the updated Lagrangian description method based on the 2nd Piola-Kirchhoff stress tensor and the Green strain tensor is used for the nonlinear finite element formulation. The progressive failure analysis is adopted in order to grasp the failure characteristics. The postbuckling experiment of the laminated composite-stiffened-curved panel had been done to verify the finite element analysis. The buckling load and the postbuckling ultimate load are compared in parametric study.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.2
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• pp.71-77
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• 2009

In the automotive industry, aluminum is widely used to reduce the vehicle weight. Aluminum curved extruded components are used for the design of frame parts. This study investigates the curvature extrusion process to produce the aluminum curved suspension arm. In the curvature extrusion process, the bending process is simultaneously carried out with the extrusion process. Firstly, porthole extrusion was investigated by using FE analysis to produce aluminum suspension arm. And then the bending process condition was determined to produce the final suspension arm with the required curvature. In this research, the guide roll movement causes the bending of extruded product. The moving distance and velocity of guide roll were controlled to meet the required curvature of suspension arm. Finally, the curved suspension arm was manufactured by the curvature extrusion experiment under the proposed curvature extrusion condition.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1173-1178
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• 2007

The robot for narrow space is used in searching, investigating or cleaning. Up to now variety of researches on in-pipe robots have been introduced. However it is still hard to overcome vertical or curved passage. In most cases of narrow space robots are able to travel just aimed diameter which was selected when those are developed. Also, a large percentage of robots are not able to detect the configuration of pipe or circumstance. In this paper we present a robot called PAROYSⅡ for narrow space with vertical and curved passage. This proposed robot is not affected at all to variance of pipes, vertical or horizontal passages, curved pipes, projecting parts and parallel planes. In addition to that, it will perceive the internal configuration of pipe and terrain, which will be not only available to control navigating scheme by itself, but also mappable about the passage which the robot traveled. Core points in the design and structure are introduced and preliminary verification is given.

• Structural Engineering and Mechanics
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• v.7 no.3
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• pp.277-288
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• 1999

This paper presents a fuzzy optimum design of axisymmetrically loaded thin shells of revolution. This paper consists of two parts, namely: an elastic analysis using the new curved element for finite element analysis developed in this study for axisymmetrically loaded thin shells of revolution, and the volume optimization on the basis of results evaluated from the elastic analysis. The curved element to meridian direction is used to develop the computer program. The results obtained from the computer program are compared by exact solution of each analytic example. The fuzzy optimizations of thin shells of revolution are done using [Model 2] which is in the form of a conventional crisp objective function and constraints with non-membership function, and nonlinear optimum GINO (General Interactive Optimizer) programming. In this paper, design examples show that the fuzzy optimum designs of the steel water tank and the steel dome roof could provide significant cost savings.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.42-45
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• 2008

Recently, aluminum is widely used to reduce the vehicle weight. Aluminum curved extruded products are used for the design of automotive frame parts. This study focuses on the determination of process condition fur automotive bumper beam with various curvatures. In this study, a curvature prediction model has been proposed considering the geometric relationship and the characteristic of the curvature extrusion equipment. Using the proposed model and FE analysis, the appropriated process condition was determined to produce the bumper beam. Finally, curvature extrusion experiment was carried out to verify the effectiveness of the proposed curvature prediction model and the process condition.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.34-36
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• 2009

This paper proposes an effective lane detection algorithm using hugh transform and lane model. The proposed lane detection algorithm includes two major components, i.e., lane marks segmentation and an exact lane extraction using a novel postprocessing technique. The first step is to segment lane marks from background images using HSV color model. Then, a novel postprocessing is used to detect an exact lane using Hugh transform and lane models(linear and curved lane models). The postprocessing consists of three parts, i.e, thinning process, Hugh Transform and filtering process. We divide input image into three regions of interests(ROIs). Based on lane curve function(LCF), we can detect an exact lane from various extracted lane lines. The lane models(linear and curved lane mode]) are used in order to judge whether each lane segment is fit or not in each ROIs. Experimental results show that the proposed scheme is very effective in lane detection.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1587-1591
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• 2009

Safety of railroad is result of reliability which is received from test & evaluation of system. Railroad system is consisted of various sub system such as vehicle, supply of electric power, signal, communication, rail track construction, operation. To secure safety of railroad, evaluation about parts, assembly, sub system, whole system etc.. that compose railroad is essential. In this paper, I wish to describe for results that analyze korean tilting vehicle's derailment coefficient developed by national research achievement. Result that evaluation korean tilting vehicle's running safety, verified that secure even if speed-up 30 km/h than operating speed of present in curved track.