• The Journal of Engineering Geology
• /
• v.11 no.2
• /
• pp.191-203
• /
• 2001

We investigate mechanical anisotropy dependent of rock fabric and its relationship with microcracks in the Pocheon Granite. Uniaxial compressive strengths range from 177MPa to 212MPa and the elastic constants are 48GPa-62GPa. The tensile strengths are 6.9MPa~8.5MPa and ultrasonic wave velocities range between 3,200m/sec and 3,700m/sec, indicating that mechanical anisotropy is strongly dependent of rock fabric. The minimum anisotropy ratio is 14% and the maximum is 24%, depend on the mechanical properties. The preferred orientations of microcracks are closely related with the directions of rock fabric. The preferred orientations of microcracks in feldspar are governed by the direction of mineralogical axis and are different from the directions of rock fabric. However, microcracks in quartz grains are very long and parallel to the directions of rock fabric, indicating that directions of rock fabric may be governed by the preferred orientations of microcracks in quartz grains. The preferred orientations of microcracks measured by differential strain analysis and microscopic observation are slightly different. That may be caused by different methodology. Lengths and numbers of microcrack are measured by microscopic observation. However, differential strain analysis measures the widths of microcracks.

• The Journal of the Petrological Society of Korea
• /
• v.13 no.3
• /
• pp.133-141
• /
• 2004

We have studied the characteristics of rock cleavage for the Pocheon granite with Jurassic emplacement age. Photomicrographs were used to observe and analyze microcracks from the granite. Three sets of microcrack planes are recognized; (1) the rift plane developed parallel to the principal sets of microcracks, (2) the grain plane parallel to the secondary sets of microcracks, (3) the hardway plane perpendicular to both rift and grain planes. The microcracks developed in the granite shows higher polution, mean length and density in the order of rift plane, grain plane and hardway plane. The fracturing characteristics of the granite are closely related to the development of these three planes.

• Korean Journal of Cognitive Science
• /
• v.10 no.3
• /
• pp.39-49
• /
• 1999

The space of IID([ndependently, Identically Distributed) textures was built with axes of mean luminance and contrast, and studied on what kind of mechanisms were required to mediate texture segregation in this space. The conjecture was tested that one of these mechanisms is sensitive to the differences between the means of textures to be discriminated, whereas the other is sensitive to the differences between variances. The probability of discrimination was measured for various pairs of textures in the lID space The data were well fit by a model in which discrimination depends on two mechanisms whose responses are combined by probability summation. The conjecture was rejected that two mechanisms respectively tuned to mean and variance of texture function in segregation. Discrimination within space is mediated by 2 independent channels however: the 2 independent channels are not exactly tuned to texture mean and variance. One m mechanism was primarily sensitive to texture mean, whereas the other was sensitive to b both texture mean and variance.

• The Korean Journal of Air & Space Law and Policy
• /
• v.24 no.2
• /
• pp.211-234
• /
• 2009

North Korea conducted the launcher test, which, as North Korea claimed, belonged to the sovereign rights for the purpose of peaceful utilization and exploration of the outer space. The launching was allegedly done for the sole purpose of putting the satellite into earth orbit, while international community stressed the fact that the orbiting of satellite was not confirmed and that the technology used was not distinct from the purpose of building intercontinental ballistic missile. UN Security Council adopted the resolutions which took the effect that the launching was deemed as the missile launching, not the mere launcher test. North Korea declared the moratorium of suspending its test activity. Controversial issues have been raised regarding whether the launcher itself has the legal status of enjoying the freedom of space flight based upon the 1967 Outer Space Treaty. The resolutions, however, has put forward a binding instrument forbidding the launching. UN Security Council resolutions, however, should be read not as defining the missile test illegal, in that the language of resolutions, such as 'demand', should be considered as not formulating a sort of obligatory act or inact. On the other hand, the resolutions should be read as having binding force with respect to any activity relating to the weapons of mass destruction. The resolution 1718 is written in more specific language such as 'decides that the DPRK shall suspend all activities related to its ballistic missile programme and in this context re-establish its pre-existing commitments to a moratorium on missile launching'. Therefore, the lauching activity of the North Korea is banned by the UN Security Council resolution. It should be noted that the resolution does not include any specific provisions defining the space of activity of the North Korea as illegal. But, the legal effect of the moratorium is not denied as to its launching itself, which is corresponding to the missile test clearisibanned in accordance with the resolutions.

• The Journal of Engineering Geology
• /
• v.11 no.1
• /
• pp.51-62
• /
• 2001

Jurassic granites of three sites, Pocheon, Geochang and Habcheon, were analysed with respect to the characteristics of the rock cleavage. Microscopic analysis for the oriented thin sections of the specimens was conducted by using the scanline survey technique to measure microcrack direction, spacing and length. The results showed that the preferred orientations of microcrack developed in quartz and feldspar arc coincident with the orientation of quarry planes. The length of microcrack is related to grain size. The length of microcrack in coarse-grained granite is longer than that in relatively fine-grained granite. In all granites, microcracks related to the preferred orientations are well developed in order of rift, grain and hardway planes in number, length and density.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
• /
• v.6 no.8
• /
• pp.11-19
• /
• 1985

• The Journal of the Petrological Society of Korea
• /
• v.20 no.4
• /
• pp.219-230
• /
• 2011

Jurassic granite from Hapcheon was analysed with respect to the characteristics of the rock cleavage. The phases of distribution of microcracks were well evidenced from the enlarged photomicrographs(${\times}6.7$) of the thin section. The planes of principal set of microcracks are parallel to the rift plane and those of secondary set are parallel to the grain plane. These rift and grain microcracks are mutually near-perpendicular on the hardway planes. Consequently the rock cleavage of Jurassic granite from the studied quarry can be related to the preferred orientation of microcracks. Microcrack parameters such as number, length and density show an order of rift > grain > hardway. These results indicate a relative magnitude of the rock cleavage. Meanwhile, brazilian tensile strengths were measured with respect to the six directions. The results revealed a strong correlation between mechanical property with microcrack parameters.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.31 no.4
• /
• pp.26-28
• /
• 1994

인명사고 예방 및 해양환경 보존을 위하여 국제해사기구(IMO)에서는 1993년 11월 4일 잠정 선 박조종성 결의안으로 채택하였으며, 이에 대한 해설서 MSC/Circ. 644(1994. 6. 6)를 발표하였다. 본 선박조종성 시운전해석법은 선박조종성 표준과 해설서를 기초로 하여 작성하였다.

• 전기의세계
• /
• v.25 no.6
• /
• pp.49-54
• /
• 1976

전기공학에서 방전현상 즉 절연파괴문제는 복잡하고 미해결의 문제가 아직도 않아 극히 증요한 Thema로 되여있다. 더구나 이 plasma, laser등의 방전응용분야의 발전과 더불어 방전현상은 항상 흥미있는 문제들을 제공하여 주고 있으나 관계하는 인자가 너무나도 많고 순수한 형태로 현상을 파악하는 것이 곤란하여 마치 수렁에 발을 넣는것과 같다고까지 말하여 왔다. 그러나 전자, X선의 발견등 근대물리학발전의 단서를 이룬것은 방전이라고 하여도 과언은 아니다. 또 현재 세계의 많은 학자가 다투어 연구하고 있는 핵융합 plasma의 연구에 대해서도 그 원류는 방전이라 할 수 있다. 이와 같이 방전의 연구에 시작하여 빛나는 많은 성과를 올렸으며 더욱이 최근 방전현상에 관한 연구가 발전함에 따라 많은 변화를 가져왔다. 즉 plasma의 이론 및 실험의 전개, gas절연, 고분자고체절연, 극저온액체절연 등의 신절연기술의 발달, 500-1,000KV의 초고전압절연이나 직류고전압절연등의 기술개발, laser, 기타 방전가공등 방전응용기술의 발달은 괄목하다 하겠다. 여기에 수반하여 방전현상에 관한 이론이나 실험 Data도 여러 면에서 크게 일신되였지만 아직도 개발되지 못한 미해결의 문제가 너무나도 많으며 그 중에서도 특히 고체, 액체절연물에 있어서는 더욱 그러하다.

• KLA journal
• /
• v.12 no.1
• /
• pp.17-21
• /
• 1971

이 원고는 날로 변화 발전하는 도서관학 및 봉사개념의 변화에 따라 1966년에 편간된 용어집의 수정증보와 더 나아가서는 용어사전으로서 개정할 필요성이 관계에서 논의되어온 바 본회 전문위 용어분위에서는 작업을 결의하고(69.7.8) 연구에 착수하여 지난해에 Documentation 분야의 시안을 게재한 바 있고 이번에 총류 및 일반적인 용어에 대한 해설을 실었다. 이 원고를 읽으시고 좋은 의견을 사무국으로 보내주시기 바란다.