• 호남수학학술지
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• 제41권4호
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• pp.725-744
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• 2019

In this paper we introduce some new types of double difference sequence spaces defined by a new definition of convergence of double sequences and a double series with the help of sequence of Orlicz functions and a four dimensional bounded regular matrices A = (a_rtkl). We also make an effort to study some topological properties and inclusion relations between these sequence spaces. Finally, we compute the closed ideals in the space 𝑙²_∞.

• 대한수학회지
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• 제39권6호
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• pp.963-973
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• 2002

We study torsion phenomena in the integral cohomology of finite if-spaces X through the Eilenberg-Moore spectral sequence converging to H＊($\Omega$X; Z$_{p}$). We also investigate how the difference between the Z$_{p}$-filtration length f$_{p}$(X) and the Z$_{p}$-cup length c$_{p}$(X) on a simply connected finite H-space X is reflected in the Eilenberg-Moore spectral sequence converging to H＊($\Omega$X;Z$_{p}$). Finally we get the following result: Let p be an odd prime and X an n-connected finite H-space with dim QH＊ (X;Z$_{p}$) $\leq$ m. Then H＊(X;Z) is p-torsion free if (equation omitted).tion omitted).

• Kyungpook Mathematical Journal
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• 제58권2호
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• pp.271-289
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• 2018

Let 0 < q < ${\infty}$. In this study, we introduce the spaces ${\mathcal{BV}}_q$ and ${\mathcal{LS}}_q$ of q-bounded variation double sequences and q-summable double series as the domain of four-dimensional backward difference matrix ${\Delta}$ and summation matrix S in the space ${\mathcal{L}}_q$ of absolutely q-summable double sequences, respectively. Also, we determine their ${\alpha}$- and ${\beta}-duals$ and give the characterizations of some classes of four-dimensional matrix transformations in the case 0 < q ${\leq}$ 1.

• Kyungpook Mathematical Journal
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• 제54권1호
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• pp.73-86
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• 2014

In the present paper we introduce difference paranormed sequence spaces $c_0(\mathcal{M},{\Delta}^n_m,p,u,{\parallel}{\cdot},{\cdots},{\cdot}{\parallel})$, $c(\mathcal{M},{\Delta}^n_m,p,u,{\parallel}{\cdot},{\cdots},{\cdot}{\parallel})$ and $l_{\infty}(\mathcal{M},{\Delta}^n_m,p,u,{\parallel}{\cdot},{\cdots},{\cdot}{\parallel})$ defined by a Musielak-Orlicz function $\mathcal{M}$ = $(M_k)$ over n-normed spaces. We also study some topological properties and some inclusion relations between these spaces.

• Kyungpook Mathematical Journal
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• 제57권4호
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• pp.631-640
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• 2017

The aim of this paper is to introduce the binomial sequence spaces $b_0^{r,s}(\nabla)$, $b_c^{r,s}(\nabla)$ and $b_{\infty}^{r,s}(\nabla)$ by combining the binomial transformation and difference operator. We prove that these spaces are linearly isomorphic to the spaces $c_0$, c and ${\ell}_{\infty}$, respectively. Furthermore, we compute the Schauder bases and the ${\alpha}-$, ${\beta}-$ and ${\gamma}-duals$ of these sequence spaces.

• 한국콘텐츠학회논문지
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• 제8권9호
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• pp.19-26
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• 2008

유비쿼터스 컴퓨팅의 발전에 따라 일대일 개인화 서비스를 위한 인프라스트럭처가 구축되면서, 사용자의 상황과 환경, 즉 상황인식 기반 서비스의 중요성이 부각되고 있다. 스마트 홈은 현실공간과 가상공간을 연결하여 가상공간에서 현실의 상황을 정보화하고 이를 활용하여 사용자 중심의 지능화된 서비스를 제공하는 기술이다. 본 논문에서는 스마트 홈에서 마이닝을 이용한 행동 순차 패턴 발견을 제안하였다. 마이닝을 이용하여 위치 트랜잭션에서 발생하는 위치간의 연관 규칙에 시간의 변이를 추가하여 행동 순차 패턴을 발견하였다. 인식된 시간 순서에 따라 사용자가 이동한 경로의 파악 및 행동 방향을 예측하고 그에 따른 서비스가 가능하다. 마이닝을 이용한 행동 순차 패턴의 성능 평가를 하기 위해 대응표본 t검정을 실시하여 유용성을 검증하였다. 평가 결과, 서비스에 대한 만족도의 차이가 통계적으로 의미가 있음을 증명하였고 높은 만족도를 보임을 확인하였다. 따라서 본 연구 결과를 활용하면 시장성 증대와 고부가 가치를 창출할 수 있을 것으로 기대하며 다양한 응용 분야에 활용이 가능하다.

• Journal of Astronomy and Space Sciences
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• 제28권3호
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• pp.203-216
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• 2011

To prepare for a future Korean lunar orbiter mission, semi-optimal lunar capture orbits using finite thrust are designed and analyzed. Finite burn delta-V losses during lunar capture sequence are also analyzed by comparing those with values derived with impulsive thrusts in previous research. To design a hypothetical lunar capture sequence, two different intermediate capture orbits having orbital periods of about 12 hours and 3.5 hours are assumed, and final mission operation orbit around the Moon is assumed to be 100 km altitude with 90 degree of inclination. For the performance of the on-board thruster, three different performances (150 N with $I_{sp}$ of 200 seconds, 300 N with $I_{sp}$ of 250 seconds, 450 N with $I_{sp}$ of 300 seconds) are assumed, to provide a broad range of estimates of delta-V losses. As expected, it is found that the finite burn-arc sweeps almost symmetric orbital portions with respect to the perilune vector to minimize the delta-Vs required to achieve the final orbit. In addition, a difference of up to about 2% delta-V can occur during the lunar capture sequences with the use of assumed engine configurations, compared to scenarios with impulsive thrust. However, these delta-V losses will differ for every assumed lunar explorer's on-board thrust capability. Therefore, at the early stage of mission planning, careful consideration must be made while estimating mission budgets, particularly if the preliminary mission studies were assumed using impulsive thrust. The results provided in this paper are expected to lead to further progress in the design field of Korea's lunar orbiter mission, particularly the lunar capture sequences using finite thrust.

• 대한수학회보
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• 제52권3호
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• pp.865-880
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• 2015

We present new sufficient convergence criteria for the convergence of the secant-method to a locally unique solution of a nonlinear equation in a Banach space. Our idea uses Lipschitz and center-Lipschitz instead of just Lipschitz conditions in the convergence analysis. The new convergence criteria can always be weaker than the corresponding ones in earlier studies. Numerical examples are also provided in this study to solve equations in cases not possible before.

• 건축역사연구
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• 제17권4호
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• pp.83-95
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• 2008

This study was firstly to reflect upon the background of the generation and the urban spatial value and significance of the medieval plaza. The main aim of this study was to extract the spatial determinants which give the great influence on the formation of the medieval plaza and in addition the endogenous rules and aesthetical grounds regarding the respective elements. Especially they could be applied to the design guideline. They are dimension(volume and scale), shape, elevation as the morphological elements and enclosure, proportion, grade difference, spatial sequence and plaza group as the spatial determinants and visual sequence, visual or spatial boundary, approaching axis and perspective effect as the aesthetic and visual elements and function(use), human behaviour as the social-behavioral elements and otherwise, for instance, plaza furniture, ground decoration and vegetation. This study was intended to analyze each elements based on the classical historical literatures and to suggest the planning conditions for composing the ideal plaza referring to the cases and literature review on the medieval plaza and finally is expected to contribute to the plaza design methodology.

• Investigative Magnetic Resonance Imaging
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• 제22권4호
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• pp.229-239
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• 2018

Purpose: To assess the diagnostic performance in detecting rotator cuff tears at 3T of non-arthrographic shoulder magnetic resonance imaging (MRI) using 3D isotropic turbo spin-echo (TSE-SPACE) sequence as compared with 2D sequences. Materials and Methods: Seventy-four patients who were arthroscopically confirmed to have underwent non-arthrographic shoulder MRI with 2D sequences and TSE-SPACE were included. Three independent readers retrospectively scored supraspinatus and infraspinatus tendon (SST-IST) and subscapularis tendon (SCT) tears on 2D sequences and TSE-SPACE. Results: The mean sensitivity, specificity, and accuracy of the three readers were 95%, 100%, and 95% on TSE-SPACE and 99%, 93%, and 98% on 2D sequences for detecting SST-IST tears, respectively, whereas those were 87%, 49%, and 68% on TSESPACE and 88%, 66%, and 77% on 2D sequences for detecting SCT tears, respectively. There was no statistical difference between the two sequences, except for in the specificity of one reader for detecting SCT tears. The mean AUCs of the three readers on TSE-SPACE and 2D sequences were 0.96 and 0.98 for detecting SST-IST tears, respectively, which were not significantly different, while those were 0.71 and 0.82 for detecting SCT tears, respectively, which were significantly different (P < 0.05). Conclusion: TSE-SPACE may have accuracy and reliability comparable to conventional 2D sequences for SST-IST tears at non-arthrographic 3T shoulder MRI, whereas TSE-SPACE was less reliable than conventional 2D sequences for detecting SCT tears.