• 한국치위생학회지
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• 제20권5호
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• pp.743-752
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• 2020

Objectives: The objectives of this study were to investigate the distribution and level of periodontopathic bacteria with the general characteristics and oral health condition of the elderly. Methods: A total of 335 elderly individuals aged 65 years or older who lived in Ganghwa-gun, Incheon, were included in the study. Oral examination, investigation through a questionnaire, and collection of saliva were carried out. The collected saliva was analyzed for the distribution and levels of bacteria (red and orange complex bacteria) by real-time polymerase chain reaction. Statistical analyses were performed using chi-square test, t-test, one-way analysis of variance, and Pearson's correlation coefficient with SAS statistical software version 9.4. Results: Among the general characteristics, there were significant differences in the distribution of Porphyromonas gingivalis, Treponema denticola, and Parvimonas micra depending on sex, age, and dental visits (p<0.05). The number of remaining teeth and denture use were related to the distribution of periodontopathic bacteria, except T. denticola (p<0.05). Additionally, periodontitis was related to the distribution of P. gingivalis (p<0.05). As the number of remaining teeth increased, the copy number of red and orange complex bacteria also increased (p<0.05). Those individuals who did not use dentures and had periodontal disease had more periodontopathic bacteria (p<0.05). Conclusions: The distribution and copy number of periodontopathic bacteria in the elderly were more related to oral health condition than to general characteristics. In particular, the distribution and copy number of periodontopathic bacteria were higher in subjects with multiple remaining teeth, no dentures, and periodontal disease.

• Genomics & Informatics
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• 제14권4호
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• pp.216-221
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• 2016

Osteoporotic fractures (OFs) are critical hard outcomes of osteoporosis and are characterized by decreased bone strength induced by low bone density and microarchitectural deterioration in bone tissue. Most OFs cause acute pain, hospitalization, immobilization, and slow recovery in patients and are associated with increased mortality. A variety of genetic studies have suggested associations of genetic variants with the risk of OF. Genome-wide association studies have reported various single-nucleotide polymorphisms and copy number variations (CNVs) in European and Asian populations. To identify CNV regions associated with OF risk, we conducted a genome-wide CNV study in a Korean population. We performed logistic regression analyses in 1,537 Korean subjects (299 OF cases and 1,238 healthy controls) and identified a total of 8 CNV regions significantly associated with OF (p < 0.05). Then, one CNV region located on chromosome 20q13.12 was selected for experimental validation. The selected CNV region was experimentally validated by quantitative polymerase chain reaction. The CNV region of chromosome 20q13.12 is positioned upstream of a family of long non-coding RNAs, LINC01260. Our findings could provide new information on the genetic factors associated with the risk of OF.

• 한국연소학회지
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• 제10권3호
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• pp.25-33
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• 2005

Fast-time instability is investigated for diffusion flames with Lewis numbers greater than unity by employing the numerical technique called the Evans function method. Since the time and length scales are those of the inner reactive-diffusive layer, the problem is equivalent to the instability problem for the $Li\tilde{n}\acute{a}n#s$ diffusion flame regime. The instability is primarily oscillatory, as seen from complex solution branches and can emerge prior to reaching the upper turning point of the S-curve, known as the $Li\tilde{n}\acute{a}n#s$ extinction condition. Depending on the Lewis number, the instability characteristics is found to be somewhat different. Below the critical Lewis number, $L_C$, the instability possesses primarily a pulsating nature in that the two real solution branches, existing for small wave numbers, merges at a finite wave number, at which a pair of complex conjugate solution branches bifurcate. For Lewis numbers greater than $L_C$, the solution branch for small reactant leakage is found to be purely complex with the maximum growth rate found at a finite wave number, thereby exhibiting a traveling nature. As the reactant leakage parameter is further increased, the instability characteristics turns into a pulsating type, similar to that for L < $L_C$.

• 한국도서관정보학회지
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• 제44권4호
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• pp.399-419
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• 2013

이 연구는 우리나라 공공도서관의 규모를 나타내는 8가지 변인을 대상으로 2011년도 통계데이터를 적용한 분포에서 어떤 독특한 특성이 나타나는지를 실증적으로 분석하였다. 그 결과 8가지 규모변인들 모두에서 멱함수 법칙이 나타나는 복잡계 현상이 발견되었다. 우리나라 공공도서관의 규모에서 양극화가 발생한 것이다. 특히 연면적, 직원수, 도서수, 예산의 변인에서는 지프의 법칙이 나타났다. 그리고 등록회원수, 자료실 이용자수, 대출자수, 대출권수의 변인에서는 지프의 법칙보다 더 심하게 불균등한 분포가 나타났다. 따라서 우리나라 공공도서관 규모의 양극화 현상을 해소할 수 있는 정책의 개발이 요구된다.

• Journal of applied mathematics & informatics
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• 제14권1_2호
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• pp.81-96
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• 2004

The level-m scaled circulant factor matrix over the complex number field is introduced. Its diagonalization and spectral decomposition and representation are discussed. An explicit formula for the entries of the inverse of a level-m scaled circulant factor matrix is presented. Finally, an algorithm for finding the inverse of such matrices over the quaternion division algebra is given.

• 한국주거학회논문집
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• 제10권2호
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• pp.155-163
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• 1999

The purpose of this study was to investigate the residents' actual usage at three rest areas and three playgrounds in an apartment complex. This study was conducted with field study in J apartment complex in Incheon from August 14 to August 30, 1998. According to the results of the study, there were more users in playgrounds than in the rest areas. The rest area near the place for the elderly in the complex was used mainly by the elderly females. The playground located near the main entrance of the complex was frequently used because it is the biggest one in size and has an enough space for playing. Furthermore, the condition of shading areas by trees and buildings influenced the rate of use of the residents. Therefore, to increase the usage rate of rest areas and playgrounds, they should be located near to the places which have community amenities and should have accessible entrance for residents. Landscape design of the apartment complex should be done with the plot plan of the complex simultaneously. Moreover, the number and the kinds of trees to be planted in the apartment complex should be considered carefully.

• Kyungpook Mathematical Journal
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• 제50권4호
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• pp.509-536
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• 2010

In this paper, we investigate curvature-adapted and proper complex equifocal submanifolds in a symmetric space of non-compact type. The class of these submanifolds contains principal orbits of Hermann type actions as homogeneous examples and is included by that of curvature-adapted and isoparametric submanifolds with flat section. First we introduce the notion of a focal point of non-Euclidean type on the ideal boundary for a submanifold in a Hadamard manifold and give the equivalent condition for a curvature-adapted and complex equifocal submanifold to be proper complex equifocal in terms of this notion. Next we show that the complex Coxeter group associated with a curvature-adapted and proper complex equifocal submanifold is the same type group as one associated with a principal orbit of a Hermann type action and evaluate from above the number of distinct principal curvatures of the submanifold.

• 한국실내디자인학회논문집
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• 제17권5호
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• pp.80-90
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• 2008

This study analyzes interior features of indoor community facilities, focused on apartment complexes in capital area selected by 'Award of best living apartment' during $2000{\sim}2007$. First we analyze community facilities' concept, present standards of installment, present condition, then the size of each complex compared with legal standards. Also, we analyze interior features(spacial layout, furniture and furnishings, interior finishing materials, interior color), too. Research methods included both data survey and site visiting inquiry. Data survey method analyzes size of each complex using community facilities' floor plans, and site visiting inquiry analyzes type and feature of community facilities. Survey target was total 11 complexes, 7 in Seoul, 4 in Gyeonggi-do. The result is as follows. 1) It is needed to improve legal standards of installment, and to provide space with flexibility and changeability in order to allow alternation of usage purpose by resident's claim. 2) To determine size of community facilities, we must planned not only by the number of households, but by legal standards of supply according to the number of households, the rate of net area, and the recommended size per person. 3) The area of community facilities in apartment complex that residents use doesn't considered user's convenience. So it us needed to add each facility's recommendation in response to user's needs.

• 한국수학사학회지
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• 제15권3호
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• pp.17-24
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• 2002

It will be described the discovery of fundamental algebras such as complex numbers and the quaternions. Cardano(1539) was the first to introduce special types of complex numbers such as 5$\pm$$\sqrt{-15}$. Girald called the number a$\pm$$\sqrt{-b}$ solutions impossible. The term imaginary numbers was introduced by Descartes(1629) in “Discours la methode, La geometrie.” Euler knew the geometrical representation of complex numbers by points in a plane. Geometrical definitions of the addition and multiplication of complex numbers conceiving as directed line segments in a plane were given by Gauss in 1831. The expression “complex numbers” seems to be Gauss. Hamilton(1843) defined the complex numbers as paire of real numbers subject to conventional rules of addition and multiplication. Cauchy(1874) interpreted the complex numbers as residue classes of polynomials in R[x] modulo $x^2$＋1. Sophus Lie(1880) introduced commutators [a, b] by the way expressing infinitesimal transformation as differential operations. In this paper, it will be studied general quaternion algebras to finding of algebraic structure in Algebras.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.209-216
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• 2010

A spectrally arbitrary complex sign pattern A is a complex sign pattern of order n such that for every monic nth degree polynomial f(x) with coefficients from $\mathbb{C}$, there is a matrix in the qualitative class of A having the characteristic polynomial f(x). In this paper, we show a necessary condition for a spectrally arbitrary complex sign pattern and introduce a minimal spectrally arbitrary complex sign pattern $A_n$ all of whose superpatterns are also spectrally arbitrary for $n\;{\geq}\;2$. Furthermore, we study the minimum number of nonzero parts in a spectrally arbitrary complex sign pattern.