• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1627-1633
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• 2012

A deep-sea pressure vessel needs to protect the internal electrical equipment from the high external pressure. Thus, the pressure vessel should be designed to be watertight and structurally safe. In this study, a cylindrical-type pressure vessel comprising a hollow cylinder and cover plates at both ends is investigated. For communication between the internal electronic equipment and the external device, holes are bored on the cover plate to install underwater connectors. Considering the type of internal equipment and underwater connector specifications, multiple holes may be required. These holes can affect the structural safety of the pressure vessel cover plate. In this study, the optimum design of the hole arrangement in consideration of the structural safety of the cover plate was performed.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.404-413
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• 1995

System parameters (extrusion temperature, extrusion pressure, specific mechanical energy, mean residence time) were analysed on three different screw configurations during twin-screw extrusion of wheat bran. Experiments were conducted over a screw speed of $280{\sim}380\;rpm$, feed rate of $22{\sim}38\;kg/hr$ and moisture content of $17{\sim}33%$ using screws assembled with 3, 4, and 5 reverse screw elements (RSE) adjacent to the heating zone of the barrel. Extrusion temperature increased with increasing RSE but it decreased with increasing feed rate and moisture content. Decreasing the filling ratio of the screw resulted in a lower extrusion pressure, and increasing the length of the RSE gave similar results due to the higher temperature and lower viscosity of melted dough. It was also observed that increasing the feed rate and decreasing moisture content resulted in the reduced extrusion pressure. Specific mechanical energy (SME) decreased when the feed rate and moisture content increased, and SME increased when using RSE posses from 3 to 5. Screw configuration posses with 4 RSE yielded the longest RT, and the smaller the die hole, the higher the RT. In contrast, RT decreased when the feed rate increased. With increasing moisture content RT for 3 RSE increased, but that for 4 and 5 RSE decreased.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.281-286
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• 2014

In grape vineyards, whitish spots in a cloud shape have been often observed on the fruit surface recently. However, the cause of the halo spot symptom was unknown, hindering countermeasures to be properly designed for the control. A small hole in the middle of the formless halo spot remained as a scar formed by oviposition of the thrips. It became later a suberized scab, which is separated from the epidermal cells on the surface either to be retained on or to be detached from it as time proceeds. Such a symptom is distinguished from the feeding damages caused by thrips or true bugs occurring on the grape fruits. With DNA extracted from the egg-shell found in the hole, molecular diagnosis by amplifying an ITS2 region with universal primers and subsequently digesting the PCR product by an restriction enzyme (RsaI) revealed that the egg was laid by Frankliniella occidentalis. In addition, a mitochondrial COI sequence confirmed that the halo spot symptom was formed by its oviposition. This study provides accurate information on the peculiar damage symptom caused by oviposition of F. occidentalis that could be useful in the control strategies for this pest in vineyards.

• Conservation Science in Museum
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• v.26
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• pp.67-82
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• 2021

Two golden beads (Buyeo 5336) housed at the Buyeo National Museum were discovered in 1993 near the site of an ancient workshop in Neungsan-ri in Buyeo-gun, Chungcheongnam-do Province. These rare examples from the Baekje Kingdom of an application of granulation have maintained their original form intact, and thus serve as important materials for the investigation of production techniques applied. This study analyzed the composition of the golden beads using a portable X-ray fluorescence analyzer, a stereo microscope, and a scanning electron microscope with an energy dispersive X-ray spectrometer. The manufacturing technique was examined through the observation of the micro-shape and the surface condition and by a composition analysis of the joint part. In both beads, a hole was pierced in a hollow body and the bead was decorated with golden wires around the hole and gold granules in other parts. In some areas, golden granules had been attached to the gold plate and golden wires were then placed over the granules. The purity of both the wires and the granules was analyzed as 23.6 - 23.7K. A high copper content was detected in some of the parts where the granules were attached. The findings of a previous reproduction experiment and study of production methods suggest that the beads were made using the copper diffusion technique.

• Conservation Science in Museum
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• v.24
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• pp.17-36
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• 2020

This paper describes the consevation treatment of eleven bigyeokjincheolloe bomb shells that were excavated from the Joseon-period local government office and fortress of Mujang-hyeon (present-day Mujang-myeon) in Gochang in 2018. It also provides information on the production method of the shells revealed through CT scanning, gamma-ray transmission imaging, and metallographic analysis. In preparation for the special exhibition "Bigyeokjincheolloe" at the Jinju National Museum in 2019 (July 16 to August 25), contaminants were removed from the shells and their surface was reinforced during the first phase of conservation treatment. Furthermore, the closures for the shells were identified for the first time. Regarding the production of the shells, the CT scanning and gamma-ray transmission imaging identified many blowholes in the interior of the body and the use of a chaplet on the side of one shell. The side of the body proved to be relatively thinner than the top and bottom. The traces of a hole for pouring molten metal into the center of the bottom indicates that molten metal was indeed emptied into the inverted body. In the metallographic analysis of two of the bodies and one lid, cementite and pearlite structures were identified on the body, indicating that it was made by casting. The presence of the ferrite structure with a partial distribution of the pearlite along with non-metallic inclusion in the lid suggested that the lid was made by forging.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.1
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• pp.55-60
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• 2011

In the present work, isogeometric analysis in linear elasticity problem is conducted using the basis functions from NURBS. The objectives of isogeometric analysis introduced is to integrate both geometric modeling(CAD) and computational analysis(CAE), and this can be accomplished from direct usage of geometric modeling by NURBS as the computational mesh. The merit of the isogeometry analysis is that NURBS surface are able to represent exact geometry from the control points and knot vectors, and also subsequent refinement is relatively simple relatively. In order to verify the computer codes developed in this study, it has been applied to two structural models of which geometry are simple ; 1) circular cylinder subjected to the constant internal pressure loading, 2) square plate with circular hole at center subjected to uniform tension. The exact solutions of these two models are available. Convergence of the approximate solutions by the present code for the isogeometry analysis are investigated by mesh refinement with inserting knots (h-refinement) and by mesh refinement with order elevation of the basis functions (p-refinement).

• Journal of the Korea Fashion and Costume Design Association
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• v.18 no.3
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• pp.71-83
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• 2016

This study attempted to analyze trends of structural changes in the front middle part of men's underwear and get basic data for the development of men's underwear patterns. In terms of a research method, the structure and pattern of the front middle part of men's underwear were analyzed by referring to the design and description of the drawing, focusing on men's underwear which targeted to isolate penis from scrotum among the 'men's underwear' or 'functional men's underwear'-related patents. According to the study, three topics were obtained as follows: a support attached to the inside of the front middle part; inner cloth attached to the inside of the front middle part; change in the structure of the front middle panel. The aspects by the specific topic targeted to isolate penis from scrotum and prevent the scrotum from adhered to a thigh are as follows: 1) When a support is attached to the inside of the front middle part, the following three methods are proposed: Penis isolated from scrotum by a rest which is designed using the band; penis and scrotum rested in the band and in a pocket respectively; protruded rest inside the front middle part of the underwear. 2) When an inner cloth is attached to the inside of the front middle part, the following methods are designed: A pocket-type inner cloth is attached; isolation of penis hole from the scrotum pocket using a rectangular separator; U-shaped pocket designed to rest penis and scrotum is attached. 3) Regarding change in the structure of the front middle panel, the integration of penis and scrotum resting parts can be divided into two cases: Securing a space using wrinkles; keeping it voluminous using the vertical line. In this all-in-one penis and scrotum-holding type, in addition, different front panel patterns were applied.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.1005-1016
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• 2002

In this paper, a 2 GHz tapered shape of multiport power divider/combiner modified from the model published by [10] and adopted PBG(Photonic Band Gap) structure is proposed. Parameters determining electrical property of the circuit structure have been analyzed by HFSS simulation. For input matching, balance of output signals and phase linearity at each output port, one circular hole has been etched out on the circuit surface. 1:2 and 1:3 power dividers/combiners designed by this study have been compared with the same circuits designed by the method of [10] in terms of S-parameters. As a result, it has been found that tile modified structure and PBG of power divider/combiner have improved return loss more than 20 dB and another 18 dB. respectively, at 2 GHz.

• Conservation Science in Museum
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• v.7
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• pp.25-31
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• 2006

We performed the conservation treatment for Bigyeokchinjeonnoe (A kind of time bomb in the Joseon Dynasty) excavated from Hwawangsanseong Fortress in Changnyeong-gun, Gyeongsangnam-do Province. Part of the Bigyeokchinjeonnoe has been lost; we did not restore the lost part so that one can observe the inside through it. The results of X-ray investigation and C. T (Computed Tomography) scan proved the generation of many blowholes around the molding line during the casting process; a hole in the casting mold to maintain inner mold during casting was identified on the surface and traces of fortifying this part with iron plate were also identified. The main ingredients of the blue corrosion on the surface were identified as O, Fe, P, Si and Al by SEM/EDS analysis. The result of XRD analysis identified the blue corrosion as vivianite [Fe₃(PO₄)₂·8H₂O]. The metal structure clarified its material was gray cast iron.

• Journal of the Korea Convergence Society
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• v.8 no.7
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• pp.123-129
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• 2017

Morphological and ultrastructural characteristics of human hair medulla was investigated with scanning electron microscopy and transmission electron microscopy. The medulla is located in the central position of hair shaft and appear greatly variable forms which discontinuous shape arranged from hair root to apical portion according to longitudinal axis. The thickness of medulla from a single hair presented as very variable in size. The diameter of cross section of human hair medulla measured as $21{\mu}m$ and longitudinal section showed $27{\mu}m$. It grows up to 1/3 from 1/4 in diameter of human hair shaft. It appears emptied hole during separating of macrofibrils in the keratinocyte. The empty space measured $6.5{\mu}m$ in diameter as maximum size and it was filled with air.