• The Bulletin of The Korean Astronomical Society
• /
• v.31 no.1
• /
• pp.52.2-52.2
• /
• 2006

• Proceedings of the Zoological Society Korea Conference
• /
• 1998.10b
• /
• pp.163.2-163
• /
• 1998

No Abstract, See Full Text

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 1999.04a
• /
• pp.27-28
• /
• 1999

• Journal of The Korean Astronomical Society
• /
• v.19 no.2
• /
• pp.63-68
• /
• 1986

In this paper we deal with the orientation and the deformation of the circular light bundle passing in a static bounded gravitational field. The properties of caustic of the gravitational lens are discussed.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2000.05a
• /
• pp.64-65
• /
• 2000

• Journal of applied mathematics & informatics
• /
• v.11 no.1_2
• /
• pp.445-451
• /
• 2003

In this paper we study asymptotic equivalence between linear differential system x' = A(t)x and its perturbed system y' = A(t)y(y) + g(t).

• Journal of The Korean Astronomical Society
• /
• v.19 no.1
• /
• pp.11-14
• /
• 1986

It is shown in this paper that the astigmatic property of single gravitational lens in static bounded gravitational field can be retained, if n-gravitating body as a whole acts simultaneously as gravitational lens.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.08a
• /
• pp.51.4-51
• /
• 1998

• Proceedings of the Korean Magnestics Society Conference
• /
• 2000.09a
• /
• pp.363-364
• /
• 2000

• Journal of the Korea Concrete Institute
• /
• v.15 no.1
• /
• pp.110-116
• /
• 2003

Recently, as concrete structure becomes high rise and large scaled tendency, demands for high performance concrete such as high strength, high fluidity and high durability has been increased. Even though high performance concrete performs high strength, workability and durability, compared to with those of normal concrete, it is more brittle than normal concrete. Accordingly, this paper is intended to improve toughness and compressive strength through investigating the mechanical properties of the high performance concrete confined with metal lath, glass fiber and carbon fiber laterally in the case of 30% and 40% of W/B. According to the results, the compressive strength increases in order of metal lath, carbon fiber and glass fiber. Considering strain-stress curve with the kinds of material for lateral confinement, while brittleness failure occurs in plain concrete just after maximum load, it is improved in some degree in confined concrete due to increase of the strain by increase of toughness. Elastic modulus increases slightly in case of confined concrete, like the compressing strength.