• Journal of the Chungcheong Mathematical Society
• /
• v.34 no.2
• /
• pp.181-188
• /
• 2021

Let X be a nondegenerate reduced closed subscheme in ℙⁿ. Assume that π_q : X → Y = π_q(X) ⊂ ℙ^n-1 is a generic projection from the center q ∈ Sec(X) \ X where Sec(X) = ℙⁿ. Let Z be the singular locus of the projection π_q(X) ⊂ ℙ^n-1. Suppose that I_X has the almost minimal presentation, which is of the form R(-3)^β_2,1 ⊕ R(-4) → R(-2)^β_1,1 → I_X → 0. In this paper, we prove the followings: (a) Z is either a linear space or a quadric hypersurface in a linear subspace; (b) $H^1({\mathcal{I}_X(k)})=H^1({\mathcal{I}_Y(k)})$ for all k ∈ ℤ; (c) reg(Y) ≤ max{reg(X), 4}; (d) Y is cut out by at most quartic hypersurfaces.

• Korean Journal of Plant Taxonomy
• /
• v.49 no.2
• /
• pp.101-106
• /
• 2019

A pollen morphological study was conducted using light and scanning electron microscopy involving six species belonging to the subtribe Neoguillauminiinae. Pollen samples from the six species are tricolporate, and the colpi are surrounded by broad margo, with the widest width in the equator, narrower toward the pole, and rounded at the end. Based on the pollen morphology, pollen of the species in the subtribe Neoguillauminiinae were divided into four types: the Neoguillauminia type (T1), the C. collinus type (T2), the C. casuarinoides type (T3) and the C. paucifolius type (T4). The generic divergence between Neoguillauminia and Calycopeplus was supported by the pollen characters of the size, amb and lumina shape. In particular, the traits of rounded shape in the outline of the polar view and circular lumina, which appear only in the pollen grains of N. cleopatra, support the recognition of Neoguillauminia as a monotypic genus. Calycopeplus oligandrus and C. paucifolius had the same reticulate pattern of pollen grains, supporting Forster's hypothesis that these two species are closely related. On the other hand, the close relationship between the morphologically similar C. collinus and C. casuarinoides was not supported by the pollen characters. Within the subtribe there are two equally parsimonious hypotheses regarding the evolution of exine characters. The first consists of two changes of microreticulate through parallel evolution from the primitive reticulate exine, and the second is that the microreticulate pattern is differentiated from the reticulate state and then reversed to reticulate pollen grains.

• Korean Journal of Environmental Biology
• /
• v.38 no.4
• /
• pp.611-615
• /
• 2020

A marine red algal species was collected from Pyengdae-ri, Gujwa in Jeju, Korea during a survey of marine algal flora. This alga shares the generic features of Callophyllis(Gigartinales, Kallymeniaceae), and is characterized by erect and membranous thalli, branches dichotomously or trichotomoulsy divided, margin somewhat undulate or entire and tetrasporangia scattered irregularly in the cortex. In a phylogenetic tree based on rbc L sequences, the Korean alga nests in the same clade as C. mageshimensis originally described from Japan. The genetic distance between both sequences within the clade was 0.0-0.1%. Based on the morphological and molecular data, the alga was identified as Callophyllis mageshimensis. This is the first record of C. mageshimensis in Korean marine algal flora.

• Korean journal of applied entomology
• /
• v.14 no.3 s.24
• /
• pp.155-161
• /
• 1975

The results of studies on the synthesis of B group vitamins by plant pathogenic bacteria indicate that most bacteria utilize thiamine, nicotinic acid, biotin and P-Aminobenzoic acid as growth factors. Riboflavin (vitamin $B_2$) was produced by most bacterial genera including the Corynebacteria but with the exception of C. rathay and C.fasciant. The results suggest that the ability to produce riboflavin is not a generic characteristic of Corynebacterium, and that the accuracy of the ultra-violet light method (one of the diagnostic tests for potato bacterial ring rot disease caused by Corynebacterium sepedonicum) must he reconsidered.

• Journal of the Korean Society of Systems Engineering
• /
• v.7 no.1
• /
• pp.9-21
• /
• 2011

Assuming that the Capability Maturity Model Integration for Development v1.2 (CMMI) could be applied to an organization more effectively if the content similarities among practices were improved in terms of structure and composition, this paper presents the analysis of the correlations between the CMMI Specific Practices (SP) and Generic Practices (GP) for the Maturity Level 2 and 3 Process Areas using the Chi-square independence test. According to the analysis, a 22.2% correlation was observed. To minimize the problem of repeatedly applying similarities, 6 GPs that are highly correlated with the SPs were grouped together. Then, three different improvement plans: 1) development of a standard template-based project plan, 2) establishment of a configuration management system based on open source software to control work products and leverage experience, and 3) establishment of project assurance through an independent quality assurance-based organization and intensive review by higher-level management - were defined.

• Journal of the Korean Mathematical Society
• /
• v.48 no.2
• /
• pp.341-365
• /
• 2011

In this paper, we establish general stratawise higher jet evaluation transversality of J-holomorphic curves for a generic choice of almost complex structures J (tame to a given symplectic manifold (M, $\omega$)). Using this transversality result, we prove that there exists a subset $\cal{J}^{ram}_{\omega}\;{\subset}\;\cal{J}_{\omega}$ of second category such that for every $J\;{\in}\;\cal{J}^{ram}_{\omega}$, the dimension of the moduli space of (somewhere injective) J-holomorphic curves with a given ramication prole goes down by 2n or 2(n - 1) depending on whether the ramication degree goes up by one or a new ramication point is created. We also derive that for each $J\;{\in}\;\cal{J}^{ram}_{\omega}$ there are only a finite number of ramication profiles of J-holomorphic curves in a given homology class $\beta\;{\in}\;H_2$(M; $\mathbb{Z}$) and provide an explicit upper bound on the number of ramication proles in terms of $c_1(\beta)$ and the genus g of the domain surface.

• Wind and Structures
• /
• v.4 no.1
• /
• pp.63-72
• /
• 2001

This paper presents results of a study on wind loads and wind induced dynamic response of bridge jointed twin-towered buildings. Utilizing the high-frequency force balance technique, the drag and moment coefficients measured in wind tunnel tests, and the maximum acceleration rms values on the top floor of towers, are analyzed to examine the influence of building's plan shapes and of intervals between towers. The alongwind, acrosswind and torsional modal force spectra are investigated for generic bridge jointed twin-towered building models which cover twin squares, twin rhombuses, twin triangles, twin triangles with sharp corners cut off, twin rectangles and individual rectangle with the same outline aspect ratio as the twin rectangles. The analysis of the statistical correlation among three components of the aerodynamic force corroborated that the correlation between acrosswind and torsional forces is significant for bridge jointed twin-towered buildings.

• Journal of Magnetics
• /
• v.21 no.1
• /
• pp.125-132
• /
• 2016

High gradient magnetic separation (HGMS) is the most commonly used magnetic cell separation technique in biomedical science. However, parameters determining target cell capture efficiencies in HGMS are still not well understood. This limitation leads to loss of information and resources. The present study develops a bead-capture theory to predict capture efficiencies in HGMS. The theory is tested with CD3- and CD14-positive cells in combination with paramagnetic beads of different sizes and a generic immunomagnetic separation system. Data depict a linear relationship between normalized capture efficiency and the bead concentration. In addition, it is shown that key biological functions of target cells are not affected for all bead sizes and concentrations used. In summary, linear bead-capture theory predicts capture efficiency ($E_t$) in a highly significant manner.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2009.05a
• /
• pp.14.1-14.1
• /
• 2009

We found a high yield synthetic route to organic-soluble metal nanoparticles in the concentrated organic phase. The organic phase contains metal salt, amines, fatty acids, nonpolar solvent, and reducing agent. Even using only generic chemicals, organic-soluble silver and copper nanoparticles could be easily obtained by this simple and rapid reaction scheme at large scale. The hydrocarbon-protected metal nanoparticles showed excellent dispersion properties and were successfully printed onto polymer substrates. The printed pattern was heated at $200^{\circ}C$, which showed very low specific electrical resistance (< 10 uOhm$\cdot$cm), sufficient for conducting line of various printable devices.

• Korean Journal of Clinical Pharmacy
• /
• v.19 no.1
• /
• pp.61-64
• /
• 2009

The study was designed to compare the rate and extent of absorption of two enalapril tablets (10 mg), which has been widely used for the treatment of hypertension. This bioequivalence study was conducted using a standard preparation as reference and a generic as test in 24 male healthy volunteers. After an overnight fast, a single dose of the test or reference drugs were given with a washout period of 7 days. Heparinized blood samples were serially collected up to 10 hr. Plasma enalapril concentrations were quantified using a validated LC-MS/MS method. The data obtained for each subject was evaluated for $C_{max}$ and $AUC_{10hr}$ with respect to 90% confidence interval for log-transformed data. The 90% confidence intervals were log(0.9384)~log(1.1160) for $AUC_{10hr}$ and log(0.9482)~log(1.1474) for $C_{max}$. Thus, we concluded that the test and reference formulation are bioequivalent in terms of rate and extent of absorption.