• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.913-918
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• 2001

This paper investigates insulating effects and strength properties of concrete under cold climate carrying out the experiment with insulating forms on the slab member. According to test results, under $-10^{\circ}C$ of outer temperature, the surface of concrete exposed to outer temperature goes below zero after 10hours since exposed. And, the surface of concrete covered with vinyl and blanket goes below zero after 42hours. However, the surface of concrete covered with insulating materials such as polystyrene foam does not drop below zero until 55hours. And, according to coring sample strength test, compressive strength cured with insulation shows much higher strength than no insulation curing condition and vinyl and blanket curing condition.

• Journal of the Korean Society of Combustion
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• v.17 no.3
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• pp.46-52
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• 2012

3D DNS is performed for n-heptane spray turbulent jet combustion. Diesel-like conditions are considered including single and multiple injections. Conditional statistics are obtained for multiple Lagrangian flame groups of sequentially evaporating fuel. Each fuel group represents the conditional statistics of an independent Lagrangian flame group. Sequentially evaporating fuel goes through different histories and residence times over the ignition delay period. Multiple flame groups are required for accurate description of combustion of a spray jet that goes through a long injection duration or multiple injections.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.78-84
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• 2005

The main goal of this work is to study the effects of temperature and volume fraction of fiber on the Charpy impact test with GF/PP composites. The critical fracture energy and failure mechanisms of GF/PP composites are investigated in the temperature range of 60^{\circ}C$ to -50^{\circ}C$ by impact test. The critical fracture energy increased as the fiber volume fraction ratio increased. The critical fracture energy shows a maximum at ambient temperature and it tends to decreases as temperature goes up or goes down. Major failure mechanisms can be classified such as fiber matrix debonding, fiber pull-out and/or delamination and matrix deformation.

• Journal of the Korean Mathematical Society
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• v.48 no.2
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• pp.341-365
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• 2011

In this paper, we establish general stratawise higher jet evaluation transversality of J-holomorphic curves for a generic choice of almost complex structures J (tame to a given symplectic manifold (M, $\omega$)). Using this transversality result, we prove that there exists a subset $\cal{J}^{ram}_{\omega}\;{\subset}\;\cal{J}_{\omega}$ of second category such that for every $J\;{\in}\;\cal{J}^{ram}_{\omega}$, the dimension of the moduli space of (somewhere injective) J-holomorphic curves with a given ramication prole goes down by 2n or 2(n - 1) depending on whether the ramication degree goes up by one or a new ramication point is created. We also derive that for each $J\;{\in}\;\cal{J}^{ram}_{\omega}$ there are only a finite number of ramication profiles of J-holomorphic curves in a given homology class $\beta\;{\in}\;H_2$(M; $\mathbb{Z}$) and provide an explicit upper bound on the number of ramication proles in terms of $c_1(\beta)$ and the genus g of the domain surface.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12
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• pp.1115-1120
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• 2003

In this paper, we investigated the position dependent stress distribution of indium-tin-oxide (ITO) film on Polycarbonate (PC) substrate by external bending force. It was found that there are the maximum crack density at the center position and decreasing crack density as goes to the edge, In accordance with crack distribution, it was observed that the change of electrical resistivity of ITO islands is maximum at the center and decrease as goes to the edge. From the result that crack density is increasing at same island position as face plate distance (L) decreases, it is evident that the more stress is imposed on same island position as L decreases.

• Journal of The Korean Astronomical Society
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• v.36 no.2
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• pp.61-66
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• 2003

We have examined the relationship between the speeds of coronal mass ejections (CMEs) and the GOES X-ray peak fluxes of associated flares. Noting that previous studies were possibly affected by projection effects and random association effects, we have considered two sets of carefully selected CME-flare events: four homologous events and four well-observed limb events. In the respective samples, good correlations are found between the CME speeds and the GOES X-ray peak fluxes of the associated flares. A similarly good correlation is found for all eight events of both samples when the CME speeds of the homologous events are corrected for projection effect. Our results suggest that a close relationship possibly exists between CME kinematics and flaring processes.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.128-131
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• 2004

Magnesium alloys are being extensively used in weight-saving applications and as a potential replacement for plastics in electronic and computer applications. Magnesium alloy has some good characteristics, EMI shielding property and high specific strength. Nevertheless their high brittleness make it uneasy to process the magnesium. Magnesium alloys are extruded like aluminium alloys. The present work was done to find a characteristic of magnesium alloy(AZ31) changing the extrusion ratio 8.5, 19.1, 49 respectly and changing the die half angle $30^{\circ},\;45^{\circ},\;60^{\circ}$. Here this present done by the hydrostatic extrusion in the hot condition, $310^{\circ}$. The higher the extrusion ratio goes, the higher the extrusion force goes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.635-641
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• 1994

Recently, Improving the energy efficiency of a pneumatic system and reducing the consumption of compressed air were a concern of scholars at domestic and abroad. The using fields of a pneumatic system are widely used in factory automation of manufacturing line, chemical factories with explosiveness danger and petroleum industries etc. In particular, Pneumatic cylinder is applied to feeding work of workpiece, jig tools and press mechanism, reciprocation and rotary motion with rack and pinion. In this study, The experimental apparatus consisted to pneumatic cylinder, dual supply pressure regulator and solenoid valve. The dual supply pressure regulator connected to outlet port of solenoid valve. The supply pressure (4.5kgf/cm$\^$2/) of compressed air goes into the rodless chamber 1 to drive the pistion rod forward which is named working stage. The supply pressure(2kgf/cm$\^$2/) of compressed air goes into the rod chamber 2 to drive the piston rod backward which is named no-working stage. Accordingly, The research results of this study can be obtained to Energy-Saving Effects of the compressed air about 35%.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.112.1-112.1
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• 2011

We present numerical simulations of inverse energy cascade and in driven three-dimensional (3D) electron magnetohydrodynamic (EMHD) turbulence. It has been known that inverse energy cascade only occurs in two-dimensional (2D) turbulence. However, we demonstrate that inverse energy cascade occurs in 3D driven EMHD turbulence. When magnetic helicity is injected on a small-scale, magnetic energy goes up to larger scales. The energy spectrum clearly shows inverse energy cascade. At the same time, magetic helicity spectrum also shows that the helicity goes up to larger scales. We obviously confirm inverse energy cascade. Net magnetic helicity for scales larger than the driving scale shows linear growth, and magnetic energy shows non-linear growth. On the other hand, when we drived turbulence without magnetic helicity, we do not observe inverse energy cascade.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.10 no.1
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• pp.306-331
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• 1997

A difference in a views of the Ong(癰) and juh(疽). In the Ong-juh(癰疽) of the Young-Chu(靈樞), if the Ki(氣) and Hul(血) are blocked in a man's body, the heat(熱) generated consists of Pus(膿). Pus(膿) which goes into the man's body and doesn't deteriorate the five viscera(五臟) is Ong(癰). Juh(疽) is pus(膿) which goes deeply into the man's body does hurt the muscle and bone. Tal-Juh(脫疽) is an ailment in the toe. It is a sort of the gangrene of the extremities. In a literature study oh the Tal- Juh(脫疽), it obtained some opinions, so it is report.