• Railway Journal
• /
• v.18 no.5
• /
• pp.79-81
• /
• 2015

• KOREAN POULTRY JOURNAL
• /
• v.9 no.4 s.90
• /
• pp.81-82
• /
• 1977

• 건축구조
• /
• v.10 no.4
• /
• pp.47-51
• /
• 2003

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.28 no.4
• /
• pp.425-431
• /
• 2015

Based on a bond-based peridynamics theory for dynamic crack propagation problems, this paper presents a design sensitivity analysis and optimization method. Peridynamics has a peculiar advantage over the existing continuum theory in the mathematical modelling of problems where discontinuities arise. For the design optimization of the crack propagation problems, a non-shape design sensitivity is derived using the adjoint variable method. The obtained adjoint sensitivity of displacement and strain energy turns out to be very accurate and efficient compared to the finite different sensitivity. The obtained design sensitivities are futher utilized to optimally control the position of bifurcation point in the design optimization of crack propagation in a plate under tension. A numerical experiment demonstrates that the optimal distribution of material density could delay the position of bifurcation.

• Journal of Korea Port Economic Association
• /
• v.23 no.1
• /
• pp.61-73
• /
• 2007

Creating more efficient and effective intermodal transportation service in Northeast range is a critical issue because of more increased trade volume & demand for intermodal service in the world market and geographical barriers associated with goods transportation, especially in Korea, China and Japan. This study examines the possibility of Rail-ferry introduction and possible route in Northest area which can provide each country mutual economical and logistical satisfaction. But, this study requires more empirical and concrete examination based on the cost & benefit analysis.

• Journal of the Korean Chemical Society
• /
• v.18 no.6
• /
• pp.408-414
• /
• 1974

The direct reactions of titanium tetrachloride with piperidine and diphenylamine in dichloromethane have been studied by examining the isolated reaction products. In the reaction with piperidine, titanium tetrachloride undergoes both addition and substitution reactions as in the following: $TiCl_4+C_5H_{10}NH{\to}TiCl_4{\cdot}C_5H_{10}NH$$TiCl_4+C_5H_{10}{\to}TiCl_3{\cdot}NC_5H_{10}+HCl$ The addition reaction is relatively fast and completed in minutes whereas the substitution reaction is very slow. The both reaction products coprecipitated with piperidine hydrochloride formed during the substitution reaction were isolated and characterized. The reaction with diphenylamine resembles to the above reaction but the addition compound could be obtained in pure crystal form.

• Journal of Veterinary Clinics
• /
• v.27 no.1
• /
• pp.11-16
• /
• 2010

A white pelican, Pelecanus onccrotalus, was imported from Tanzania and died 5 days later in Daejeon zoo in Korea. The proventriculus of bird was found to contain parasites. The taxonomic status of the nematodes was studied by morphological and morphometric analysis using light and scanning electron microscopy. Only one species Contracaecum occurred in the proventriculus with high values of infection. Morphological characters of the parasite were as follows: The worms have three lips without cuticular dentigerous ridges, and well developed interlabia. The interlabia have a triangular shape, non-bifurcated. Males possess numerous preanal papillae (69-79 pairs) arranged in single subventral rows. Paracloacal papillae were separated 5 postanal papillae and 1 larger pairs. All the characters of the above studied specimens are very similar to those of C. rudolphii complex. Accordingly, the parasites from white pelican were identified belong to the C. rudolphii complex.

• Journal of the Mineralogical Society of Korea
• /
• v.21 no.4
• /
• pp.373-382
• /
• 2008

First reported geochemical characteristics of mantle xneoliths (spinel peridotites) from Sunheul-ri, Jeju Island, provide important clues for understanding the lithosphere composition, equilibrium temperature, and the period of entrainment and transport of the xenoliths in the host magma. Core and rim of mineral phases in the xenoliths are constant chemical compositions as $Fo_{89-90}$ of olivines. The ranges of equilibrium temperature, obtained by two pyroxenes geothermometer, are about $951{\sim}1035^{\circ}C$ for Sunheul-ri spinel peridotite xenoliths and are similar to the range of equilibrium temperatures for the xenoliths from other sites in Jeju island. The period of entrainment and transport of the xenoliths in the host magma of Sunheul-ri mantle xenoliths is about 42 days.

• Journal of the Korean Magnetics Society
• /
• v.13 no.5
• /
• pp.211-215
• /
• 2003

We fabricated the synthetic ferrimagnetic layers (SyFL) of permalloy/X (X=Ru, V)/permalloy by varying the X thickness, and investigated the changes of coercivity (H$\sub$c/), spin flopping field (H$\sub$sf/), and saturation magnetization field (H$\sub$s/) with a superconducting quantum interference device (SQUID). We also observed the microstructure with a cross sectional transmission electron microscope (TEM). Permalloy SyFL had less than 10 Oe coercivity, and H$\sub$sf/ and H$\sub$s/ could be tuned by varying ruthenium and vanadium layer thickness. The comparatively small exchange coupling in permalloy-V SyFL was caused by the intermixing of permalloy and vanadium decreasing the effective exchange coupling thickness.

• Journal of the Mineralogical Society of Korea
• /
• v.18 no.1
• /
• pp.61-72
• /
• 2005

Modal and chemical compositions of clinopyroxnes in spinel peridotites from the Baegryeong Island and the Boeun, enclosed in Miocene alkali basalt, are important for understanding the pre-eruptive temperature condition and chemical processes such as mantle depletion and enrichment. All spinel peridotites show transitional texture between protogranular and porphyroclastic textures. Temperature ranges of spinel peridotites from the Baegryeong Island and the Boeun at 15 kb are 773∼1188℃ and 705∼1106℃, respectively. The spinel peridotites from the Baegryeong Island and the Boeun have undergone the 1∼10% and 1∼4% fractional melting, which were determined by using primitive mantle-normalized Y and Yb of clinopyroxenes. LREE enrichment patterns of clinopyroxene indicate that these rocks from both areas have undergone cryptic mantle metasomatism without new minerals.