• 한국전산유체공학회지
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• 제7권4호
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• pp.28-34
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• 2002

A general purpose program for computing 3-D flows has been extended for two-phase flows with topologically complex interfaces. The 3-D interfaces are tracked by employing a coupled level set and volume-of-fluid (CLSVOF) method which not only can calculate an interfacial curvature accurately but also can achieve mass conservation well. The program has been tested through the computations of bubbles rising in a liquid. The numerical results are found to compare well with the results reported in the literature.

• 대한수학회지
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• 제42권4호
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• pp.847-856
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• 2005

M. Junger, G. Reinelt, and W. R. Pulleyblank asked the following questions ([2]). (1) Is it true that every simple planar 2-edge connected bipartite graph has a 3-partition in which each component consists of the edge set of a simple path? (2) Does every simple planar 2-edge connected graph have a 3-partition in which every component consists of the edge set of simple paths and triangles? The purpose of this paper is to provide a positive answer to the second question for simple outerplanar 2-vertex connected graphs and a positive answer to the first question for simple planar 2-edge connected bipartite graphs one set of whose bipartition has at most 4 vertices.

• 한국조경학회지
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• 제22권3호
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• pp.79-90
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• 1994

This survey was ocnducted to investgate changes of the plant community structure from 1972 to 1993 in forest of Mt. Kwanak and thirty-five plots that the size of each plot was 10m${\times}$10m(100㎡) were set up and the vegetation analysis was caried out. By the TWINSPAN analysis, the plant community of survey area were divied into Quercus mongolica, Q. mongolica-Pinus densiflora(1), Q. mongolica-P. densiflora(2), Q. acutissima community. The successional trends of the woody species were seemed to be from P. densiflora, Sorbus alnifolia to Q. mongolica in the canopy layer. But the successional trends in the understory and shrub layer were difficult to suppose. The forest vegetation of Mt. Kwanak from 1972 to 1993 was severely decreased in species number and individuals. The sensitive species for the environmental pollution were selected, and the tolerant plants for the acid soil were increased. In comparision with the DBH class distribution from 1972 to 1993, it shows that the ecological succession has stopped. In the analysis of soil characteristics, soil acidification has taken place over last twenty-two years(from pH=5.40 to pH=4.53). The concentration of K+, Ca++ was severly decreased(from K+=0.60m.e./100g to K+=0.06m.e./100g, from Ca++=3.20m.e./100g to Ca++=0.63m.e./100g), which also could seemed to be cause of plant community decline.

• 한국응용과학기술학회지
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• 제31권2호
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• pp.183-189
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• 2014

내화성 및 내화학성이 우수한 현무암사의 표면에 회분식 방법에 의한 테프론 코팅 연구의 결과를 토대로 연속식 코팅 공정 인자를 도출하기 위한 연구를 수행하였다. 현무암사를 7,5 wt% 트리에톡시트리플루오로실란(TMTFPS)으로 연속적으로 전처리 한 후, 침투제로 0.25 wt% bis(2-ethylhexyl)sulfo succinate (DOS-Na)가 함유된 20 wt% 테프론 수분산액으로 딥 코팅한 후 2 m의 $120^{\circ}C$ 건조 챔버에서 12 m/mim의 속도로 건조한 후 2 m의 $380^{\circ}C$ 소성 챔버에서 40초간 소성하여 최종 $3.4g_f/D$의 인장 강도와 $2.3g_f/D$의 루프강도를 가지는 테프론이 코팅된 고내열 재봉사용 현무암사를 제조하였다.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.1875-1880
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• 2010

A dicycle pyrazoline derivative, 1-phenyl-5-(p-fluorophenyl)-3,4-($\alpha$-p-fluoro-tolylenecyclohexano) pyrazoline, was synthesized and characterized by elemental analysis, IR, UV-vis, fluorescence spectra and X-ray single crystal diffraction. Density function theory (DFT) calculations were performed by using B3LYP method with 6-$311G^{**}$ basis set. The optimized geometry can well simulate the molecular structure. Vibrational frequencies were predicted, assigned and compared with the experimental values, which suggest that B3LYP/6-$311G^{**}$ method can well predict the IR spectra. Both the experimental electronic absorption spectra and the predicted ones by B3LYP/6-$311G^{**}$ method reveal three electron-transition bands, with the theoretical ones having some red shifts compared with the experimental data. Natural bond orbital analyses indicate that the absorption bands are mainly derived from the contribution of n $\rightarrow\pi^*$ and $\pi\rightarrow\pi^*$ transitions. Fluorescence spectra determination shows that the title compound can emit blue-light at about 478 nm. On the basis of vibrational analysis, the thermodynamic properties of title compound at different temperature have been calculated, revealing the correlations between $C^0_{p,m}$, $S^0_m$, $H^0_m$ and temperature.

• 대한수학회지
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• 제46권6호
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• pp.1309-1318
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• 2009

Let k be a positive integer, and let G be a simple graph with vertex set V (G). A Roman k-dominating function on G is a function f : V (G) $\rightarrow$ {0, 1, 2} such that every vertex u for which f(u) = 0 is adjacent to at least k vertices $\upsilon_1,\;\upsilon_2,\;{\ldots},\;\upsilon_k$ with $f(\upsilon_i)$ = 2 for i = 1, 2, $\ldot$, k. The weight of a Roman k-dominating function is the value f(V (G)) = $\sum_{u{\in}v(G)}$ f(u). The minimum weight of a Roman k-dominating function on a graph G is called the Roman k-domination number ${\gamma}_{kR}$(G) of G. Note that the Roman 1-domination number $\gamma_{1R}$(G) is the usual Roman domination number $\gamma_R$(G). In this paper, we investigate the properties of the Roman k-domination number. Some of our results extend these one given by Cockayne, Dreyer Jr., S. M. Hedetniemi, and S. T. Hedetniemi [2] in 2004 for the Roman domination number.

• Journal of Computing Science and Engineering
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• 제3권2호
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• pp.109-126
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• 2009

Taxonomies are widely used to classify information, and multiple (possibly competing) taxonomies often exist for the same domain. Given a set of correspondences between two taxonomies, it is often necessary to "merge" the taxonomies, thereby creating a unied taxonomy (e.g., that can then be used by data integration and discovery applications). We present an algorithm for merging taxonomies that have been related using articulations given as RCC-5 constraints. Two taxa Nand M can be related using (disjunctions of) the ve base relations in RCC-5: M; N ${\subseteq}$M; N ${\supseteq}$; N ${\oplus}$M (partial overlap of Nand M); and N ! M (disjointness: N ${\cap}$M = ${\varnothing}$). RCC-5 is increasingly being adopted by scientists to specify mappings between large biological taxonomies. We discuss the properties of the proposed merge algorithm and evaluate our approach using real-world taxonomies.

• East Asian mathematical journal
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• 제31권1호
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• pp.65-75
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• 2015

In modern times, coupled fixed point theorems have been rigorously studied by many researchers in the milieu of partially ordered G-metric spaces using different contractive conditions. In this note, some coupled fixed point theorems using mixed monotone property in partially ordered G-metric spaces are obtained. Furthermore some theorems by omitting the completeness on the space and continuity conditions on function, are obtained. Our results partially generalize some existing results in the present literature. To exemplify our results and to distinguish them from the existing ones, we equip the article with suitable examples.

• 대한수학회보
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• 제22권1호
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• pp.7-10
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• 1985

For each a.mem.S and f.mem.m(S), denote by $l_{a}$ f(s)=f(as) for all s.mem.S. If A is a norm closed left translation invariant subalgebra of m(S) (i.e. $l_{a}$ f.mem.A whenever f.mem.A and a.mem.S) containing 1, the constant ont function on S and .phi..mem. $A^{*}$, the dual of A, then .phi. is a mean on A if .phi.(f).geq.0 for f.geq.0 and .phi.(1) = 1, .phi. is multiplicative if .phi. (fg)=.phi.(f).phi.(g) for all f, g.mem.A; .phi. is left invariant if .phi.(1sf)=.phi.(f) for all s.mem.S and f.mem.A. It is well known that the set of multiplicative means on m(S) is precisely .betha.S, the Stone-Cech compactification of S[7]. A subalgebra of m(S) is (extremely) left amenable, denoted by (ELA)LA if it is nom closed, left translation invariant containing contants and has a multiplicative left invariant mean (LIM). A semigroup S is (ELA) LA, if m(S) is (ELA)LA. A subset E.contnd.S is left thick (T. Mitchell, [4]) if for any finite subser F.contnd.S, there exists s.mem.S such that $F_{s}$ .contnd.E or equivalently, the family { $s^{-1}$ E : s.mem.S} has finite intersection property.y.

• 분석과학
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• 제32권4호
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• pp.139-146
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• 2019

A simple and reliable analytical method based on high-performance liquid chromatography-ultraviolet detection was established for the analysis of the flowers of Chrysanthemum morifolium (CM). Luteolin-7-O-glucoside (LU7G) was chosen as a target analyte considering its content, availability, and ease of analysis. Chromatographic separation of LU7G was achieved using a Phenomenex Gemini $C_{18}$ column ($250{\times}4.6mm$, $5{\mu}m$) run with a mobile phase consisting of 0.5 % acetic acid in water and 0.5 % acetic acid in acetonitrile at a flow rate of $1.0mL\;min^{-1}$. The detection wavelength and column temperature were set at 350 nm and $40^{\circ}C$, respectively. Method validation was performed according to the AOAC guidelines and the method was specific, linear ($R^2=0.9991$ for $50-300{\mu}g\;mL^{-1}$), precise (${\leq}3.91%$RSD), and accurate (100.1-105.7 %). The limits of detection and quantification were 3.62 and $10.96{\mu}g\;mL^{-1}$, respectively. The established method was successfully applied to determine the contents of LU7G in various batches of bulk CM extracts and labscale CM extract. The developed method is a readily applicable method for the quality assessment of CM and its related products.