• Transactions of Materials Processing
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• v.8 no.6
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• pp.554-562
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• 1999

In this paper, the stress and strain behavior in near homogeneous isotropic matrix of metal like steel was studied during roll forming of thin steel sheet for cylindrical pipe. Analytical result reveals a body which is on the area of square thickness along and perpendicular to the width of thin steel sheet is in the state of plane strain during roll forming. As a result, construction of analytical method for calculating deformation load and stably deformed length along the width of strained steel sheet was established. Also, loads applied during roll forming were analyzed using two typical thin steel sheets. 12.3mm thick steel sheet with 42.5kg/㎟ yield strength of pipe and 5.3mm thick steel sheet with 32.5kg/㎟ yield strength of pipe. Through this analysis, applicability of the analytical method for deformation load during roll forming of cylindrical thin steel pipe was evaluated with a study of necessary production technology for roll forming and design technology for roll forming machine.

• The Journal of the Petrological Society of Korea
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• v.24 no.2
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• pp.65-75
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• 2015

Around Harar in the northeastern part of the Ethiopia, the Precambrian granitic gneiss and gabbro bodies are developed with several pegmatites. The rock bodies in this area have been deformed by ductile and brittle deformations developing fold and ductile shear structure, and thrust and fault.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.387-390
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• 2008

Electromagnetic forming (EMF) technology, which is one of the high speed forming methods, has been used for the forming process in various industry fields. Numerical approach by finite element simulation of the EMF process is presented in this study. The implicit code is used to obtain the numerical model of the time-varying currents that are discharged through the coil in order to obtain the transient magnetic forces. In addition, the body forces generated in the workpiece are used as the loading condition to analyze deformation of thin sheet metal workpiece using explicit code. Numerical approach for a dimpled shape by EMF process is carried out and the simulated results of the dimpled shape by EMF are reviewed in view of the deformed shape and formability evaluation.

• Structural Engineering and Mechanics
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• v.41 no.6
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• pp.735-750
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• 2012

This paper presents a comparison between two different procedures to deal with the geometric nonlinear analysis of space trusses, considering its structural stability aspects. The first nonlinear formulation, called positional, uses nodal positions rather than nodal displacements to describe the finite elements kinematics. The strains are computed directly from the proposed position concept, using a Cartesian coordinate system fixed in space. The second formulation, called corotational, is based on the explicit separation between rigid body motion and deformed motion. The numerical examples demonstrate the performances and the convergence of the responses for both analyzed formulations. Two numerical examples were compared, including a lattice beam with postcritical behavior. Despite the two completely different approaches to deal with the geometrical nonlinear problem, the results present good agreement.

• Transactions of Materials Processing
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• v.30 no.2
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• pp.74-82
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• 2021

Stretch-flangeability, which is the ability of sheet steels to be deformed into complex shapes, is a critical formability property in automobile body parts. In this study, the center-hole for hole expansion test, which is normally used to evaluate the stretch-flangeability of sheet steels, was prepared by both punching and electrical discharge machining (EDM) methods. Hole expansion ratio (HER) of punched hole was far lower than the HER of EDM drilled hole because of damage/crack in hole-edge due to punching process. The effect of hole-edge condition on HER was quantified by mechanical, fractographic and geometric factors. Based on these factors, the empirical equation used to determine HER for various sheet steels was derived using non-linear regression.

• Current Optics and Photonics
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• v.6 no.2
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• pp.196-201
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• 2022

Collagen fibers tens of nanometers in size, which constitute most of the corneal volume of the human eye, are layered in a uniform direction, and adjacent fiber layers are arranged at an angle of 90° to each other. According to the results of this study, the transmittance at 45° of interlayer rotation angle is highest, and higher than that of the 90° body structure. The transmittance is examined, concerning the polarization state of the incident light; circularly polarized light case shows higher transmittance than linearly polarized. Through this, a simulation to confirm the deformed structure of collagen fibers, which show higher transmittance than the anatomical structure of the cornea, is attempted.

• Journal of the Korean Geophysical Society
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• v.2 no.3
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• pp.201-208
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• 1999

A high-resolution seismic profile acquired across the middle part of the Pungam Basin, one of the Cretaceous sedimentary basins in Korea, has been interpreted to delineate subsurface geological structures. Boundary faults, intrusive bodies, and unconformity surfaces are identified on the seismic section. Basin fills are divided into five depositional units (Units I, II, III, IV, and V in descending order). The normal faults were formed by transtentional movement along a sinistral strike-slip fault zone. Unconsolidated sediments, a weathered layer, and sedimentary layers overly the Precambrian gneiss. The granite body intruded at the southeastern part contacts the adjacent sedimentary rocks by a near-vertical fault. Granitic intrusions caused tectonic fractures and normal faults of various sizes. An andesitic intrusive body indicates post-depositional magmatic intrusions. Continuous strike-slip movements have deformed basin-filling sediments (Units I and II).

• Korean journal of applied entomology
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• v.38 no.2
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• pp.157-164
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• 1999

A tarsonemid mite. Stet~rotc~r.sot~rrrs~puin.sk i Smiley 1967. is an important rice pest in major rice producing countries of Thailand. Philippine. China, and Taiwan. S. spinki was found first time in Korea from rice grown in environment controlled greenhouse. Rice fed by the mite showed damage symptoms of deformed panicles and inflorescence, lesions on the inner surface of leaf sheath, and browning of rice hulls. Females of S. .spi~lkwi as 263.0 pni (246.5-284.6f 12.2) in body length and 92.4 pm (79.5- 104.9 t 7.6) in body width. Body was elongate and broadest in region of hysterosoma. Body color was pale brown. Legs were robust except for the legs IV which were typical tarsonemid female legs terminating in a whiplike seta two times the length of the leg. Male of S. spir~kiw as 196.5 pm ( 176.5-222.8 + 15.8) in body length and 109.3 ym (98.6- 1 17.7 + 6.4) in body width. Anterior ends of apodemes 111 were extended further than apodemes IV. Femur IV had large inner median lateral flange. and inner anterior and outer median setae were short about equal length. Tarsal claw was stout and curved ventrally.

• Journal of Naturopathy
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• v.11 no.1
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• pp.39-50
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• 2022

Background: It is essential to investigate the functionality of the newly developed knobble shoe. Purpose: The purpose was to explore how the body shape and balance change when wearing knobble shoes. Methods: Nine subjects wearing knobble shoes after walking for a month were analyzed. Results: For knobble shoes, we created various small air pockets in the insole to stimulate the soles of the feet to induce body changes. In particular, it was to promote the arch part of the foot by making a large lump inside and outside the center of the foot's arch. After wearing knobble shoes and using them for 30 days, the average blood sugar decreased by 31.1 mg. The lowering range was 5 to 120 mg. In one patient, the result of the hemoglobin test decreased by 7.5% to 6.5%. In the shoulder tapping test for a body balance test, seven subjects leaned to the right in a barefoot state, and two people to the left. However, after wearing shoes, all of them maintained equilibrium. knobble shoes fit, and balance was all stable. There were two subjects with a short left and four subjects with a short right. Conclusions: Blood sugar decreased after wearing the knobble shoes. The deformed shape of the body was restored to its original state by the knobble supporting the foot arch area. The balance of the sole directly affects the overall posture.

• Journal of Naturopathy
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• v.8 no.2
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• pp.63-70
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• 2019

Purpose: The purpose of this study was to investigate whether Qihyul-therapy was effective against subjects of bad Qihyul circulation who had narrowed muscles of the buttocks, a distorted body shape, or pain. Methods: Qihyul-therapy used. Results: The muscles of the buttocks remained almost untouched. The elasticity of the muscles restored. The skin tone brightened, and the anal muscle strengthened after Qihyul-therapy. The subject's body was shifted to the right by -7°. The right arm was about 6 cm longer than the left arm. But after correction, the right arm was about 5 cm shorter. The distorted body was almost balanced. After neck and shoulder correction, the distance between the collarbone and neck was 7~10 cm wider. After the pelvic correction, the pain in the buttocks was relieved, and the position of the hip joint returned correctly. The right leg that was turned 45° to the left was corrected, and the length became the same. Subjects had no knees attached, their right knees were up 5 cm above the left, and their ankles bent at an angle of 30 ° relative to the left, but after correction, the knees of the two legs stably attached. The height of the knee became the normal angle. Conclusion: If the Qihyul-therapy, the spine correction Qihyul-exercise and the pelvic correction Qihyul-exercise performed steadily, the deformed body shape restored adequately, and it is useful to prevent and cure related diseases by alleviating the pains.