• Journal of applied mathematics & informatics
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• 제40권3_4호
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• pp.619-632
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• 2022

In this study, we examine rough ${\Delta}\mathcal{I}$-statistical convergence for difference sequences as an extension of rough convergence. We investigate the set of rough ${\Delta}\mathcal{I}$-statistical limit points of a difference sequence and analyze the results with proofs.

• 영어어문교육
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• 제13권3호
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• pp.23-40
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• 2007

This paper discusses why Korean speakers have problems in pronouncing some medial sonorant clusters in English. We argue that the main reasons lie in the sonority sequence requirement difference between the two languages. English does not have any specific sonority sequence preference between the medial sonorant sequences while Korean has a strict requirement between the two sonorants over a syllable boundary. This sonority sequence requirement difference between the two languages acts as an interference for Korean speakers in learning English pronunciation. This barrier for Korean speakers in acquiring correct pronunciation is implemented in a constraint ranking difference in the Optimality Theory, which is not familiar for Korean speakers. Understanding the details of sonorant production mechanisms along with the different constraint ranking will facilitate the learning process of Korean speakers learning English.

• 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.

• 대한수학회논문집
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• 제20권4호
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• pp.723-729
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• 2005

Let F be a non-trivial non-Archimedian field. The sequence spaces $\Gamma\;(F)\;and\;{\Gamma}^{\ast}(F)$ were defined and studied by Soma-sundaram[4], where these spaces denote the spaces of entire and analytic sequences defined over F, respectively. In 1997, these spaces were generalized by Mursaleen and Qamaruddin[1] by considering an arbitrary sequence $U\;=\;(U_k),\;U_k\;{\neq}\;0 \;(\;k\;=\;1,2,3,{\cdots})$. They characterized some classes of infinite matrices considering these new classes of sequences. In this paper, we further generalize the above mentioned spaces and define the spaces $\Gamma(u,\;F,\;{\Delta}),\;{\Gamma}^{\ast}(u,\;F,\;{\Delta}),\;l_p(u,\;F,\;{\Delta})$), and $b_v(u,\;F,\;{\Delta}$). We also study some matrix transformations on these new spaces.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권8호
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• pp.368-373
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• 2002

The inverse z-transform of a z-domain expression of a sequence can be Performed in many different methods among which the recursive computational method is based on the difference equation. In applying this method, a few initial values of the sequence should be obtained separately. Although the existing method generates the right initial values of the sequence, its derivation and justification are not theoretically in view of the definition of z-transform and its shift theorems. In this paper a general approach for formulating a difference equation and for obtaining required initial values of a sequence is proposed, which completely complies to the definition of the z-transform and an interpretation of the validity of the existing method which is theoretically incorrect.

• 대한수학회논문집
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• 제21권2호
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• pp.261-272
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• 2006

In this paper, we define the sequence spaces: $[V,{\lambda},f,p]_0({\Delta}^r,E,u),\;[V,{\lambda},f,p]_1({\Delta}^r,E,u),\;[V,{\lambda},f,p]_{\infty}({\Delta}^r,E,u),\;S_{\lambda}({\Delta}^r,E,u),\;and\;S_{{\lambda}0}({\Delta}^r,E,u)$, where E is any Banach space, and u = ($u_k$) be any sequence such that $u_k\;{\neq}\;0$ for any k , examine them and give various properties and inclusion relations on these spaces. We also show that the space $S_{\lambda}({\Delta}^r, E, u)$ may be represented as a $[V,{\lambda}, f, p]_1({\Delta}^r, E, u)$ space. These are generalizations of those defined and studied by M. Et., Y. Altin and H. Altinok [7].

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.499-506
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• 2013

The accurate estimation of a fault location is desired in distance protection schemes for transmission lines in order to selectively deactivate a faulted line. However, a typical method to estimate a fault location by calculating impedances with voltages and currents at relaying points may have errors due to various factors such as the mutual impedances of lines, fault impedances, or effects of parallel circuits. The proposed algorithm in this paper begins by extracting the fundamental phasor of the positive sequence currents from the three phase currents. The second-order difference of the phasor is then calculated based on the fundamental phasor of positive sequence currents. The traveling times of the waves generated by a fault are derived from the second-order difference of the phasor. Finally, the distance from the relaying point to the fault is estimated using the traveling times. To analyze the performance of the algorithm, a power system with EHV(Extra High Voltage) untransposed double-circuit transmission lines is modeled and simulated under various fault conditions, such as several fault types, fault locations, and fault inception angles. The results of the simulations show that the proposed algorithm has the capability to estimate the fault locations with high speed and accuracy.

• Journal of the Korean Statistical Society
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• 제24권1호
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• pp.219-224
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• 1995

A central limit theorem with random indices is obtained for stattionary martingale difference sequences.

• 한국정보통신학회논문지
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• 제7권4호
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• pp.630-637
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• 2003

본 논문에서는 디지털 데이터의 저작권 보호와 무단 복제 방지를 위해 기존의 M-sequence 대신 카오스 시퀀스를 이용한 새로운 워터마킹 방법에 대하여 제안한다. 강인성과 보안성은 워터마킹 처리에 있어 중요한 요소이다. 디지털 영상을 웨이브렛 변환한 후 각 부대역의 계수값들을 인간의 시각 체계를 고려한 다중 임계값으로 분류하고 카오스 시퀀스와 삽입할 워터마크 영상 그리고 랜덤 발생기로 생성된 다중 워터마크 가중치를 이용하여 워터마크 영상을 삽입하였다. 워터마크 검출은 웨이브렛 변환된 각 부대역간의 차신호를 이용하여 검출하였으며 여러가지 가능한 공격에 대해 성능 실험을 하였다. 카오스 시퀀스는 생성하기가 매우 쉬우며, 초기 값에 따라 전혀 다른 시퀀스를 생성하므로 M-sequence에 비해 보안성(security)면에서 더욱 안전하다는 장점을 갖고 있다.