• Journal of applied mathematics & informatics
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• v.29 no.5_6
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• pp.1571-1581
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• 2011

In this paper, we construct inequivalent Hadamard matrices based on several new and old full orthogonal designs, using circulant and symmetric block matrices. Not all orthogonal designs produce inequivalent Hadamard matrices, because the corresponding systems of equations do not possess solutions. The systems of equations arising when we search for inequivalent Hadamard matrices from full orthogonal designs using circulant and symmetric block matrices, can be concisely described using the periodic autocorrelation function of the generators of the block matrices. We use Maple, Magma, C and Unix tools to find many new inequivalent Hadamard matrices.

• Economic and Environmental Geology
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• v.19 no.2
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• pp.123-131
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• 1986

This study is focused on petrochemistry and petrogenesis of alkali granite which exposed at northern area of the Uljin mine in NE Korea. The rock is corresponded to the range of alkali feldspar granite and alkali feldspar quartz syenite on IUGS classification and contains characteristic Fe-rich biotite (annite) and sodic alkali amphibole (arfvedsonite). The alkali granite is the hypersolvus one-feldspar granite which is characterized by the absence of plagiclase except as a component of perthite and its normatve An contents are less than 5wt%. The bulk compositions of the alkali granite show reverse trends compared to Daly's. Tuttle and Bowen (1958) experimentally support that properties of the hypersolvus granite indicate that they have crystallized at high temperatures from a magma.

• The Journal of the Petrological Society of Korea
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• v.8 no.1
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• pp.1-13
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• 1999

The Latite Ridge Latite in the East Tintic volcanic field, Utah in USA occurs as a welded ash-flow tuff, has 63.7-66 wt% $SiO_2$ on an anhydrous basis, and shows calc-alkaline affinities. The rocks fall in the trachyte field of IUGS classification. It is characterized by unusally high $K_2O$ content (5.9-7.6 wt%), relatively high equilibration temperature (950-973$^{\circ}C$), and biotites with high $TiO_2$ content (7.4-8.2wt%). Various differentiation processes were tested using the XLFRAC program to infer the origin of the Latite Ridge Latite. The results suggests that crystal fractionation from shoshonite is one possible process to generate the Latite Ridge Latite. Shoshonite of the East Tintic volcanic field was possibly formed by crystal fractionation from a subduction-related K-, Mg-rich mafic magma.

• Journal of the Korean Mathematical Society
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• v.54 no.2
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• pp.517-543
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• 2017

Let H be a cocommutative faithfully flat Hopf quasigroup in a strict symmetric monoidal category with equalizers. In this paper we introduce the notion of (strong) Galois H-object and we prove that the set of isomorphism classes of (strong) Galois H-objects is a (group) monoid which coincides, in the Hopf algebra setting, with the Galois group of H-Galois objects introduced by Chase and Sweedler.

• Ocean and Polar Research
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• v.25 no.1
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• pp.119-128
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• 2003

Although phoscorites and carbonatites form only a minor proportion of the earth's crustal rocks, these unusual rocks and their intimate relation are of both academic and economic importance. Rare metal (Nb, Zr, Ta) and REEs mineralizations are in close relation with the differentiation of these phoscorite-carbonatite complexes (PCCs). Recent integrated petrological and geochemical data on PCCs in the Kola Alkaline Province, Arctic, indicate that phoscorites and associated carbonatites are differentiated from common 'carbonated silicate patental magma'. Various hypotheses for the genesis of phoscorite-carbonatite complexes have been proposed during the last half-century. A simple magmatic fractionation scheme can not explain the chemical and mineralogical characteristics of phoscorite and conjugate carbonatite. Instead, the hypotheses involving liquid immiscibility and coeval accumulation processes are favored to explain the mineralogical and geochemical characteristics of phoscorite and carbonatite association.

• Journal of Korea Foundry Society
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• v.18 no.6
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• pp.578-585
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• 1998

A multi-purpose code MAGMA was employed for mold design and process control in producing Al wheel by lowpressure die casting. Three-dimensional solid modeling was followed by mesh generation of casting and molds(top, bottom and side). The simulation of stability of casting cycle time, mold filling simulation with pressure variation from P1 to P2, solidification simulation by solidification time and feeding criteria, and temperature distribution of molds during processes were studied in this research. The thermal stability of molds was attained after 5 cycles when molds were preheated at $400^{\circ}C$. The pressure increase from P1 to P2 for mold filling was evaluated as slightly higher, and 6 seconds were taken for the mold filling. The cycle time was believed to be designed properly judged from the solidification time of casting and open/close time of molds.

• Geophysics and Geophysical Exploration
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• v.16 no.4
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• pp.268-274
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• 2013

Continuous seismic observation of volcanic earthquakes related to migration of magma or gas, is one of the most important methods used to monitor active volcanoes. In this review paper, we introduce the characteristics of volcanic earthquakes and their classification based on locations of foci, waveforms, frequencies, lithology, and source mechanisms. We also present some examples of successful warnings of volcanic eruptions and the present status of some observations of volcanic earthquakes in Japan, the United States, Italy, and New Zealand.

• The Journal of the Petrological Society of Korea
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• v.2 no.1
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• pp.41-52
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• 1993

We report adventages of employing MgO as a differentiation index for the Namwon granitic complex. It is shown to be much more sensitive than the usual Harker index. The complex can be divided into two groups on the basis of $TiO_2$/MgO ratio. The low $TiO_2$/MgO group consists of hornblende biotite tonalite-granodiorite, porphyritic hornblende biotite granodiorite (PHBGd) and part of biotite granite (loBG). PHBGd shows its own distinct variation in the low group. This group is characterized in most cases by the presence of hornblende, even if it occurs as a trace amount. The high $TiO_2$/MgO group consists of part of biotite granite (hiBG) and two mica granite. The major element differences between rock types are also apparent in biotite chemistry. These chemical data indicate that at least two distinct origins of magma are rquired for the complex. Two kinds of biotite granite revealed in this study show distinct geographic distribution, suggesting that a new geologic map should be made.

• Economic and Environmental Geology
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• v.21 no.1
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• pp.69-83
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• 1988

Orthogneiss of the study area is meta-igneous complex that composed of granite gneiss, porphyroblastic gneiss and migmatitic gneiss. Migmatitic gneiss produced from granite gneiss and porphyroblastic gneiss by strong ductile shearing. These rocks show mostly gneissic and partly mortar textures by strong regional metamorphism and ductile shearing during several orogenies. $^{40}Ar-^{39}Ar$ incremental-release ages of these rocks have been determined for 1 hornblende. 1 biotite and 3 muscovite concentrates separated from orthogneisses in this area. Ages of regional metamorphism and ductile shearing of these rocks are more than 5 stages(1500 Ma, 260 Ma, 190 Ma, 180-170 Ma and 160 Ma) under $300^{\circ}C$ to $500^{\circ}C$. These rocks had not been nearly effected by Daebo orogeny, because this area is far from Daebo granite bodies. The general trend of major chemical composition and mineral composition of these orthogneisses suggest that these rocks are some series of differentiated products from magma.

• Journal of the Korean Society of Industry Convergence
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• v.14 no.1
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• pp.1-7
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• 2011

Basalt originates from volcanic magma and flood volcanoes, a very hot fluid or semifluid material under the earth's crust, solidified in the open air. Basalt is a common term used for a variety of volcanic rocks, which are gray, dark in colour, formed from the molten lava after solidification. Recently, attention has been devoted to continuous basalt fibers (CBF) whose primary advantage consists in their low cost, good resistance to acids and solvents, and good thermal stability. In order to investigate reinforcement effect, this paper did FEM analysis with shell element. The result were as follows; BCF deck plate did elastic behavior to 450 kN, reinforcement effect of basalt fiber (BF) was less. But BCF's perpendicular deflection occurred little about 23 mm comparing with RC deck plate in load 627 kN. Stiffness was very improved by basalt fiber reinforcement.