• 한국철도학회논문집
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• 제9권2호
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• pp.174-179
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• 2006

Recently, the crossing tunnel has been constructed frequently to connect the separated area by highway and railroad. The construction of crossing tunnel must be progressed while maintaining the existing traffic of the highway as well as railroad. There are many cross funnelling methods such as NTR, TRCM, Messer Shield, Front Jacking, and Pipe Roof Method. The advantages of adopting RPS(Roof Panel Shield) method in crossing tunnel construction with comparing other existing cross funnelling methods are needed a little volume of concrete and easy to change the direction of cutting shoe during the construction of pipe roof, The 3-dimensional numerical analysis of RPS to consider the arching effect was performed for the application in the crossing tunnel under railroad. The earth pressure distribution and settlement were predicted when the RPS method was applied during the excavation for crossing railroad tunnel construction.

• 자연과학논문집
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• 제18권1호
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• pp.91-97
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• 2007

The Korean name "Bizooki" tree was named by the shape of winter bud which is like a slim bow. There are four scientific names in the tree which are Cleyera japonica Thunberg, Cleyera ochnacea DC, Sakakia ochnacea Nakai, and Ternstroemia gymnanthera. And the English name are Japanese Ternstroemia and Japanese Cleyera. "Bizooki" tree has planted at Buddhist temples in Japan for the ritual. The best result of stem cutting in "Bizooki" tree, 100 percent of rooting, could be accomplished in July when cuttings were done on the mixture-soil containing the same rates by volume of vermiculite, peatmoss and perlite with cuts processed with IBA 1,000 mg/l under the circumstances that 70% of shade, plastic mulching, and mist were conditioned.

• 한국CDE학회논문집
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• 제2권3호
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• pp.161-174
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• 1997

In this paper, the techniques for graphic simulation of material removal process are described. The concepts of the bounding box and base plane are proposed. With these concepts, a real-time shaded display of a Z-map model being milled by a cutting tool following an NC path can be implemented very efficiently. The base planes make it possible to detect the visible face of Z-map model effectively. And the bounding box of tool sweep volume provides minimum area of screen to be updated. The proposed techniques are suitable for implementation in raster graphic device and need a few memories and a small amount of calculation. Proposed method is written in C and executable on MS-Windows95 and Window-NT.

• 한국연초학회지
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• 제16권2호
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• pp.97-101
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• 1994

Tobacco stalks were cut and removed from the field after harvest, and urea was treated by placing it on the cutting portions of the remaining tobacco stumps. Relative virus infectivity of the root residue(compared to the fresh root residue infected with TMV) was reduced to 14.6% in December, 1993(before overwintering) and to 8.5% in March, 1994 just before transplanting, indicating that the TMV infectivity decreased remarkably, but was preserved still in the root residue in the field soil. There was no significant difference in infectivity of remaining root tissue between the treated and untreated root residue. However, as roots with urea treatment had been extensively decayed, only about one - fifth of the initial root volume remained after overwintering. TMV occurred less (by one - third) in the urea treatment than in the control, suggesting that urea treatment effectively provented tobacco from TMV infection by reducing the inoculum potential.

• 한국정밀공학회지
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• 제20권8호
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• pp.185-193
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• 2003

The modular self-wiping co-rotating twin screw extruder (SWCOR) has become the most important of twin screw machines. Screw design is one of the most important factors in determining performance of screw extruder. The screw flight and screw channel geometry of SWCOR is determined by the screw diameter, centerline distance, helix angle, and flights number. The maximum allowable throughput rate on a twin screw extruder is determined by a combination of free volume and available specific torque. In this paper we designed geometrical parameters of extruder screw and presented optimal specific torque value in K=1.55, and then developed screw design program for the screw cutting by the use of JAVA API in the twin screw extruder.

• 한국주조공학회지
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• 제18권4호
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• pp.373-382
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• 1998

Particulate reinforced aluminum alloys produced by indirect squeeze casting are difficult to shape by cutting or milling. Therefore near net shape forming of complex shapes is of high economic and technical interest. The complex shape products of $SiC_p/6061$ Al composites are fabricated by the melt-stirring and indirect squeeze casting process. The mold temperatures are $200^{\circ}C$ and $300^{\circ}C$ and applied pressures are 70, 100, and 130 MPa. The volume fractions of the reinforcements are in the range of 5 vol% to 15 vol%. The reinforcement dispersion state are observed using on optical microscope. By employing observed results systematically a correlation is demonstrated among the microstructure, particles behavior, mechanical properties and processing parameters for an optimum melt-stirring(compocasting) and indirect squeeze casting process of MMCs. A procedure to establish the optimum squeeze casting of Al-MMCs is proposed.

• East Asian mathematical journal
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• 제36권2호
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• pp.291-315
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• 2020

In this study, the geometric model of 11 factorization formulas presented in the 2015 revised national curriculum was constructed and the necessary mathematical conditions were derived in the process. As a result of the study, all of the 11 factorization formulas are geometrically modeled and 12 conditions are derived in the process. However, the basic method of directly cutting and attaching a given shape was limited to not being able to make a rectangle or rectangular parallelepiped. Therefore, the problem was solved by changing the perspective and focusing on whether rectangle or rectangular parallelepiped with the same area or volume could be constructed.

• 한국임상수의학회지
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• 제17권2호
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• pp.420-430
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• 2000

These studies were preformed to investigate the freezing conditions to achieve good post-thaw viability of spend and the practical methods of artificial insemination frozen canine semen. Semen were collected from nine male dogs which had been proved to be fertile in the past and the semen were treated for freezing procedure. Post-thaw motility and viability of canine sperm were evaluated to investigate individual tolerance of freezing, difference among freezing extenders, dif-ference among freezing equipments and freezing conditions, difference between fast and slow cooling rate, difference according to different glycerol concentration, effect of seeding on post-thaw viability, difference according to cutting part of straw, difference according to thawing temperatures, and dif-ference according to media added to thawed semen. Thawed semen for insemination were added with equal volnme of canine capacitation medium (CCM) and the volume of semen and the number per insemination were adjusted as 2-3 ml and $20-30 {\times}10^7,$ respectively. The semen were inseminated in vagina using balloon catheter and en17ryos were cellected from 9 to 11 days after the second Al to d determine fertilization.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.644-645
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• 2006

TiC-and Ti(C,N)-based cermets are excellent in semi-and final finishing of work piece during cutting operations. Typical microstructure of the cermets is a core/rim structure. The undissolved Ti(C,N) cores contribute to their high hardness while the rim phases, (Ti,M1,M2)(C,N)-type solid solutions, play great roles in enhancing the toughness. In this paper, various ultrafine pre-mixed MeC-Ni powders were synthesized and the powders were sintered or hot pressed after mixing in order to control the size and volume fractions of core and rim phases in the system. This paper will present the factors determining the microstructure along with mechanical properties.

• 전기학회논문지
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• 제66권6호
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• pp.923-926
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• 2017

In this study, a novel wideband conformal thin antenna is presented for endoscopic capsule application at the 915 MHz Industrial, Scientific and Medical (ISM) band. The thickness of the antenna is only 0.2 mm which can be wrapped inside a capsule's inner wall. By cutting meandered slots on patch, open end slots on ground and utilizing long arm, the proposed antenna can obtain significant size reduction. The net volume of the proposed antenna including substrate and superstrate is only $37.4mm^3$ ($187mm^2$ surface area). This conformal antenna has shown good performance through simulation and measurement with maximum gain of -23 dBi and wide bandwidth from 137 MHz - 205 MHz depending on different environment. In addition, the effect of internal materials specially metallic battery is discussed briefly.