• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1402-1405
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• 2004

Algorithms on modification of NURBS surface requires modeling history to change its boundary conditions. The history is stored when the surface is modeled and saved in the corresponding model file. But when the model is transferred to other systems the history generally cannot be recognized. So modification algorithms without history is highly required. Previous works on the field is concentrated in the point based modification without any restriction condition. Therefore this study is intended to develope a curved based modification algorithm with restriction conditions. A rapid modification algorithm is suggested, implemented and tested.

• 대한수학회보
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• 제54권2호
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• pp.507-519
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• 2017

We present an upper bound on the Cheeger constant of a distance-regular graph. Recently, the authors found an upper bound on the Cheeger constant of distance-regular graph under a certain restriction in their previous work. Our new bound in the current paper is much better than the previous bound, and it is a general bound with no restriction. We point out that our bound is explicitly computable by using the valencies and the intersection matrix of a distance-regular graph. As a major tool, we use the discrete Green's function, which is defined as the inverse of ${\beta}$-Laplacian for some positive real number ${\beta}$. We present some examples of distance-regular graphs, where we compute our upper bound on their Cheeger constants.

• Journal of applied mathematics & informatics
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• 제30권1_2호
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• pp.235-244
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• 2012

In this paper, we solve the three-dimensional biharmonic equation with Dirichlet boundary conditions of second kind using the full multigrid (FMG) algorithm. We derive a finite difference approximations for the biharmonic equation on a 18 point compact stencil. The unknown solution and its second derivatives are carried as unknowns at grid points. In the multigrid methods, we use a fourth order interpolation to producing a new intermediate unknown functions values on a finer grid, and the full weighting restriction operators to calculating the residuals at coarse grid points. A set of test problems gives excellent results.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.413-427
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• 1997

Porphyromonas endodontalis and Prevotella intermedia are black-pigmented anaerobic gram negative rods which have been isolated from infected root canals and submucous abscesses of endodontic origin. And they are associated with clinical symptoms such as pain, percussion, and foul odor. It has been reported that there are 3 serotypes according to capsule membrane in P. endodontalis and 2 DNA homology groups and 3 serotypes in P. intermedia, but there is no data available regarding genetic diversity for the species P. endodontalis and P. intermedia. The purpose of this study is to investigate genetic diversities between individual strains of P. endodontalis and P. intermedia which are indistinguishable by serotyping and biotyping using bacterial DNA restriction endonuclease analysis. 45 teeth with at least one clinical symptoms, with single canal, and with pulp necrosis were sampled. For sampling bacteria, access cavity was prepared after disinfecting tooth and its surroundings. Then the paper point was inserted to the apex of the canal, leave there for 15 seconds, and finally it was placed into PRAS Ringer's solution and PBS solution. P. endodontalis and P. intermedia were identified by biochemical test and IIF after subculturing black and brown colonies which were produced after 7 days of incubation on BAP in anaerobic chamber. P. endodontalis and P. intermedia strains were grown in BHI broth and whole genomic DNA was extracted by phenol-chloroform extraction technique and digested by restriction endonuclease, Eco RI and Pst I. The resulting DNA fragments were separated by agarose gel electrophoresis, stained with EtBr and photographed under UV light. The results were as follows : 1. In both P. endodontalis and P. intermedia, different serotypes could be found within a root canal of same patient. 2. There were obvious genetic heterogeneity within a patient and within a serotype in both P. endodontalis and P. intermedia. 3. P. endodontalis serotype c, isolated from different patients, exhibited limited genotypic diversity.

• 대한수학회보
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• 제48권4호
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• pp.713-724
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• 2011

We study the dynamics of transcendental entire functions with Siegel disks whose singular values are just two points. One of the two singular values is not only a superattracting fixed point with multiplicity more than two but also an asymptotic value. Another one is a critical value with free dynamics under iterations. We prove that if the multiplicity of the superattracting fixed point is large enough, then the restriction of the transcendental entire function near the Siegel point is a quadratic-like map. Therefore the Siegel disk and its boundary correspond to those of some quadratic polynomial at the level of quasiconformality. As its applications, the logarithmic lift of the above transcendental entire function has a wandering domain whose shape looks like a Siegel disk of a quadratic polynomial.

• 대한산업공학회지
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• 제25권4호
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• pp.448-458
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• 1999

This paper proposes sequential control charts with an upper bound on sample size. Existing sequential control charts have no restriction on the number of observations at a sampling point. For situations where sampling and testing an item is time-consuming or expensive, sequential control charts may not be directly applied. When the number of observations in a sampling point reaches the upper bound and there is no out-of-control signal, the proposed cumulative sequential control chart defers the decision to the next sampling point of which starting value is the value of the current statistic. Two Markov chains, inner and outer chains, are used to derive the formulas for evaluating the performance of the proposed chart. It is compared with $\bar{X}$ and cumulative sum control charts with fixed and variable sample sizes. The fast initial response (FIR) feature is studied. Guidelines for the design of the proposed charts are also given.

• Nonlinear Functional Analysis and Applications
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• 제28권1호
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• pp.1-9
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• 2023

Our aim in this paper is to give some new proofs to fixed point theorems due to Abdou [1] for mappings satisfying Reich type contractions in modular metric spaces. We removed the restriction that ω satisfies the ∆₂-type condition imposed on the results of [1]. Furthermore, Lemma 2.6 of [1] which was crucial in the proofs of the results of [1] is not needed in the proofs of our results. Our method of proof is simpler and interesting.

• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1171-1184
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• 2010

In this paper, by using fixed point theorems in cones, the existence of positive solutions is considered for nonlinear m-point boundary value problem for the following second-order dynamic equations on time scales $({\phi}(u^{\Delta}))^{\nabla}+a(t)f(t,\;u(t))=0$, t $\in$ (0, T), $u(0)=\sum\limits^{m-2}_{i=1}a_iu(\xi_i)$, $\phi(u^{\Delta}(T))=\sum\limits^{m-2}_{i=1}b_i{\phi}(u^{\Delta}(\xi_i))$, where $\phi$ : R $\rightarrow$ R is an increasing homeomorphism and positive homomorphism and ${\phi}(0)=0$. In [27], we obtained the existence results of the above problem for an increasing homeomorphism and positive homomorphism with sign changing nonlinearity. The purpose of this paper is to supplement with a result in the case when the nonlinear term f is nonnegative, and the most point we must point out for readers is that there is only the p-Laplacian case for increasing homeomorphism and positive homomorphism due to the sign restriction. As an application, one example to demonstrate our results are given.

• 한국콘텐츠학회논문지
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• 제11권6호
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• pp.337-349
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• 2011

연구의 목적은 다문화가정 이주여성의 여가관 분석을 규명하는데 있다. 이 연구는 2010년 경기도 대전 충남 충북 지역 소재 다문화가정지원센터 프로그램에 참가하고 있는 이주여성들을 모집단으로 선정한 다음 유의표집방법(purposive sampling method)을 활용하여 140명의 연구대상을 표집 하였다. 최종분석에 사용된 사례수는 총 89명이다. 설문지의 신뢰도는 Cronbach's ${\alpha}$ 값이 .613이상으로 나타났다. 결론은 다음과 같다. 첫째, 다문화가정 이주여성들의 평일 여가시간은 '1~2시간'이 가장 많다. 둘째, 다문화가정 이주여성들의 주말 여가시간은 '1~2시간'이 가장 많다. 셋째, 다문화가정 이주여성들의 여가활동만족은 '보통'이 가장 많다. 넷째, 다문화가정 여가활동 선호도는 '여행'이 가장 많다. 다섯째, 다문화가정 이주여성들의 여가활동 동반자로는 '배우자'가 가장 많다. 여섯째, 연령, 학력, 국적, 기간에 따라 다문화가정 이주여성들의 여가제약은 차이가 있다.

• BMB Reports
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• 제29권5호
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• pp.442-447
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• 1996

Mutations in codon 12, 13 and 61 of one of the three ras genes, H-ras, K-ras and N-ras, convert these genes into active oncogenes. The presence of H-ras gene mutations have important prognostic implications in various cancers. In this study, the H-ras gene mutations were investigated by two-step PCRRFLP in patients with bladder and stomach cancer. For the control experiments, T24 and SK2 cell lines were used. In a total of 36 bladder cancer patient cases, five (13.9%) mutations were found by this method. Of these, point 12 mutations were two (5.6%) cases and point 61 mutations were three (8.3%) cases. On the other hand, H-ras mutation was not found in 29 cases of stomach cancer. The results of the mutated H-ras gene confirmed by direct sequencing analysis were correlated well with PCR analysis. From the sensitivity test, the H-ras mutation was found to have about 0.2% of mutated DNA mingled in normal DNA. In conclusion, the H-ras mutation has a higher clinical Significance in bladder cancer than stomach cancer. Moreover the two-step PCR-RFLP method is sensitive, rapid and relatively simple for clinical work in detecting H-ras point mutations.