• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.9
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• pp.1478-1486
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• 2008

The human body composed of concave and convex curvatures, and the current 3D scanning technology which involves inherent measurement errors make it difficult to extract distinct curvature plot directly. In this study, a method of extracting the clear curvature plot and its application to the cycling pants design were proposed. We have developed the ergonomic pattern from the 3D human body reflecting cycling posture. For the ergonomic design line on the 3D human body, the 3D information on the lower part of four male bodies with flexed posture was analyzed. The 3D scan data of four subjects were obtained using Cyberware. As results, the iteration of the tessellated shell was executed 100 times to obtain optimized curvature plots of the muscles on the body surface, and the boundaries of the curvature plots were applied to the design lines. Maximum(Max-pattern) and mean curvature plots(Mean-pattern) were adopted in the design line of the cycling pants, and performance of those lines was compared with that of conventional princess line(Con-pattern). The average error of total area and length in the 2D pattern developed from the 3D flexed body surface in this study were very minimal($4.58cm^2$(0.19%) and 0.15mm(0.46%)), which was within the range of tolerable limits in clothing production. The pattern obtained from the flexed body reflecting cycling posture already included the contraction and extension of the cycling skin, so that the extra ease for movement and good fit was not need to be considered.

• Journal of IKEEE
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• v.20 no.4
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• pp.416-419
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• 2016

When the integration density and operating frequency increase in the electronic circuits, it is important to improve the signal transmission characteristics. In this paper, the signal transmission characteristics of the printed circuit boards are analyzed with the curvature of the pads. From the simulation results, signal transmission characteristics are improved when pad curvature increases. Pad curvature more effects on signal transmission characteristics when the thickness of the transmission line and the length of the transmission decrease.

• Honam Mathematical Journal
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• v.46 no.2
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• pp.279-290
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• 2024

In this study, tubular surfaces were introduced according to the modified orthogonal frame defined at the points where the torsion is different from zero in the 3-dimensional Euclidean space. First, the relations between the Frenet frame and the modified orthogonal frame with torsion are given. Then, the singularity, Gaussian curvature, mean curvature and basic forms of the tubular surface given according to the modified orthogonal frame with torsion were calculated. In addition, the conditions for the parameter curves of the tubular surface to be geodesic, asymptotic and line of curvature were examined. Finally, tubular surface examples based on both the Frenet frame and the modified orthogonal frame with torsion were given to support the study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.5
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• pp.104-109
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• 2011

In this paper, after an acceleration typed ion wind generator which could format strong electric field in air was manufactured and installed, the effects of the electrode configuration and distance of acceleration type ion wind generator with triangle structure on the ion wind generation characteristics were investigated. As a result, the ion wind generator with curvature multipoint electrode could generate higher ion wind velocity and ion wind generation yield than others with multipoint electrode, curvature line electrode, line electrode structure. The ion wind generator with curvature multipoint electrode showed a peak ion wind velocity of 1.33[m/s] at 19.0[kV] and a ion wind generation yield of 0.12[m/Ws] at 15.0[kV].

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.245-248
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• 1996

This paper suggests a new concept for missile guidance control, called linearized common curvature guidance law that enhances the probability to kill a target. The proposed guidance system is composed of two switching modes; one for the midcourse guidance and the other for the terminal guidance, which is switched by a specified critical value (.epsilon.). And the system and the commands are formulated and its simulations are provided in comparison with the conventional commanded line of sight guidance algorithm. Miss distance and angle of attack are denoted as performance of parameters. This new concept, common curvature guidance algorithm, revises the navigation guidance and accompanies, various considerations.

• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.333-349
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• 2019

The paper study the curvature theory of a line-trajectory of constant Disteli-axis, according to the invariants of the axodes of moving body in spatial motion. A necessary and sufficient condition for a line-trajectory to be a constant Disteli-axis is derived. From which new proofs of the Disteli's formulae and concise explicit expressions of the inflection line congruence are directly obtained. The obtained explicit equations degenerate into a quadratic form, which can easily give a clear insight into the geometric properties of a line-trajectory of constant Disteli-axis with the theory of line congruence. The degenerated cases of the Burmester lines are discussed according to dual points having specific trajectories.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.3
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• pp.81-86
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• 2008

I present a 3-D profiler specially devised for the profile measurement of specular surfaces that requires precision shape accuracy up to a few nanometer. A profile is reconstructed from the curvature of a test part of the surface at several locations along a line. The local curvature data are acquired with White-light Scanning Interferometry. Test measurement proves that the proposed profiler is well suited for the specular surface inspection like precision mirror.

• Bulletin of the Korean Mathematical Society
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• v.50 no.3
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• pp.833-837
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• 2013

In this note we establish a generalized Myers theorem under line integral curvature bound for Finsler manifolds.

• Journal of the Korean Mathematical Society
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• v.39 no.5
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• pp.693-708
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• 2002

The warped product L$\times$$_{f}$ F of a line L and a Kaehler manifold F is a typical example of Kenmotsu manifold. In this paper we determine submanifolds of L$\times$$_{f}$ F which are tangent to the structure vector field and satisfy certain conditions concerning with Ricci curvature and mean curvature.ure.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.209-212
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• 2006

Line heating with water cooling is generally adapted process in the shipyards for the forming hull surface. The purpose of this paper is to develop a model of thermal deformation in water cooling process after the line heating. In order to simulate the cooling process, heat transfer analysis was performed by assuming the effects of water cooling as a negative heat-source. Experiment for the line heating with water cooling was performed for 9 models of plates in order to verify the cooling model. By using the suggested model for the water cooling process, it could be observed that the present method predict the plate deformations in the line heating more accurately.