• Honam Mathematical Journal
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• v.38 no.2
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• pp.359-366
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• 2016

Let H be the 3-dimensional Heisenberg group, ($G=H{\times}S^1$, g) a product Riemannian manifold of Riemannian manifolds H and S with arbitrarily given left invariant Riemannian metrics respectively, and ${\Gamma}$ the discrete subgroup of G with integer entries. Then, on the Riemannian manifold ($M:=G/{\Gamma}$, ${\Pi}^*g=\bar{g}$), ${\Pi}:G{\rightarrow}G/{\Gamma}$, we evaluate the scalar curvature and the Ricci curvature.

• Bulletin of the Korean Mathematical Society
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• v.57 no.1
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• pp.109-115
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• 2020

Recently, Lesieutre constructed a 6-dimensional projective variety X over any field of characteristic zero whose automorphism group Aut(X) is discrete but not finitely generated. As an application, he also showed that X is an example of a projective variety with infinitely many non-isomorphic real structures. On the other hand, there are also several finiteness results of real structures of projective varieties. The aim of this short paper is to give a sufficient condition for the finiteness of real structures on a projective manifold in terms of the structure of the automorphism group. To be more precise, in this paper we show that, when X is a projective manifold of any dimension≥ 2, if Aut(X) does not contain a subgroup isomorphic to the non-abelian free group ℤ ∗ ℤ, then there are only finitely many real structures on X, up to ℝ-isomorphisms.

• Journal of Information Technology Application
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• v.1 no.3_4
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• pp.113-132
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• 1999

실증적인 연구들에 의하면 고객회사(client firms)와 서비스 제공업자(vendor) 간의 파트너십의 질과 범위가 정보시스템 아웃소싱의 성공적인 구현에 결정적인 역할을 하는 것으로 알려졌다. 본 연구는 이러한 정보시스템 아웃소싱 구현에 있어서 파트너십의 역할을 좀 더 심층적으로 분석하려는 노력의 일환이다. 본 연구에서의 기본 명제는 파트너십 특성들의 아웃소싱 구현에의 효과는 아웃소싱 업무의 특성(task characteristics)과 같은 상황적 요인에 의해 영향을 받을 수 있다는 것이다. 구체적으로 본 연구에서는 자산특이성(asset specificity)과 파트너십 특성간의 상호효과(interaction effect)에 중점을 두고 조사를 하게되는데, 파트너십은 관계적거래 특성(relational exchange characteristics)에 의해 구체화되었다. 207개의 미국 회사의 아웃소싱 관계를 대상으로 한 설문조사를 기반으로 한 결과에 의하면, 전반적으로 비관계적거래(discrete exchange)보다 관계적거래에 기반을 두고 아웃소싱 관계를 운영하는 것이 아웃소싱의 성공적 구현을 위하여 필수적인 것으로 보인다. 한편 상호효과를 조사하기 위해서는 MRA와 하위그룹분석(subgroup analysis)을 시행하였는데, 자산특이성과 일부 관계적거래 특성들간에 상호효과가 유의성이 있음을 발견하였다. 발견된 상호효과를 근거로 상황 변수를 고려하지 않은 연구 결과 중 확실하지 않은 결과(inconclusive results)에 대한 해석을 시도하였다.

• Journal of Plant Biotechnology
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• v.46 no.4
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• pp.255-273
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• 2019

Orchids are indispensable to the floriculture industry due to their unique floral organization. The flowers have two outer whorls of tepals including a lip (labellum), and two inner whorls, pollinia and gynostemiun (column). The floral organization and development is controlled at the molecular level, mainly by the MADS-box gene family, comprising homeotic genes divided into type I and type II groups. The type I group has four sub-groups, Mα, Mβ, Mγ, and Mδ, playing roles in seed, embryo, and female reproductive organ development; the type II group genes form classes A, B, C, D, and E, which are a part of the MIKC^C subgroup with specific roles in florigenesis and organization. The coordinated functioning of these classes regulates the development of various floral whorls. The availability of genome and transcriptome sequence data for Phalaenopsis equestris offers an opportunity to validate the ABCDE model of flower development. Hence, this study sought to characterize the MADS-box gene family and elucidate of the ABCDE model. A total of 48 identified MADS-box proteins, including 20 type I [Mα (12), Mγ (8)] and 28 type II [MIKC^C (27), MIKC*(1)] members, were characterized for physico-chemical features and domains and motifs organization. The exon-intron distribution and the upstream cis-regulatory elements in the promoter regions of MADS-box genes were also analysed. The discrete pace of duplication events in type I and type II genes suggested differential evolutionary constraints between groups. The correlation of spatio-temporal expression pattern with the presence of specific cis-regulatory elements and putative protein-protein interaction within the different classes of MADS-box gene family endorse the ABCDE model of floral development.

• Journal of Periodontal and Implant Science
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• v.47 no.5
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• pp.328-338
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• 2017

Purpose: Chronic periodontitis is an inflammatory disease induced by pathogenic bacterial accumulation. A novel index, the periodontal inflamed surface area (PISA), represents the sum of the periodontal pocket depth of bleeding on probing (BOP)-positive sites. It is advantageous for data processing and analysis because it can be treated as a continuous variable to quantify periodontal inflammation. In the present study, we evaluated correlations between PISA and periodontal classifications, and examined PISA as an index integrating the discrete conventional periodontal indexes. Methods: This study was a cross-sectional subgroup analysis of data from a prospective cohort study investigating the association between chronic periodontitis and the clinical features of ankylosing spondylitis. Data from 84 patients without systemic diseases (the control group in the previous study) were analyzed in the present study. Results: PISA values were positively correlated with conventional periodontal classifications (Spearman correlation coefficient=0.52; P<0.01) and with periodontal indexes, such as BOP and the plaque index (PI) (r=0.94; P<0.01 and r=0.60; P<0.01, respectively; Pearson correlation test). Porphyromonas gingivalis expression and the presence of serum P. gingivalis antibodies were significant factors affecting PISA values in a simple linear regression analysis, together with periodontal classification, PI, bleeding index, and smoking, but not in the multivariate analysis. In the multivariate linear regression analysis, PISA values were positively correlated with the quantity of current smoking, PI, and severity of periodontal disease. Conclusions: PISA integrates multiple periodontal indexes, such as probing pocket depth, BOP, and PI into a numerical variable. PISA is advantageous for quantifying periodontal inflammation and plaque accumulation.