• East Asian mathematical journal
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• 제21권1호
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• pp.27-39
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• 2005

We will define p-stack convergence spaces and show that each neighborhood structure is uniquely determined by p-stack convergence structure. Also, we will show that p-stack convergence spaces are a generalization of neighborhood spaces.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제15권3호
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• pp.221-227
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• 2008

We introduce and study the new concepts of interior and closure operators on strong generalized neighborhood spaces. Also we introduce and investigate the concept of sgn-continuity on SGNS.

• 대한후두음성언어의학회지
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• 제8권1호
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• pp.38-43
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• 1997

Backgroud : Now a days, most studies for professional voice user have been performed after artificial voice abuse without consideration of environmental and personal factors, and occupational specificity, therefore those studies have some problems. Objectives : To make a basic guideline for the management of untrained professional voice user, practically we ananalyzed the voice of experimental group. Materials and methods : Just after working, the sustained vowel sounds of the 15 female telephone operators (subjective group) and the 20 normal female persons (control group) were analysed, using a history paper, acoustic analyzer and videostroboscopy. Results : The most common symptom in subjective group was dysphonia. Stroboscopic findings in subjective group were as following ; posterior chink 11 cases (73%), incomplete closure 2 cases (13%), anterior chink 1 case (7%). The mean maximal phonation time in telephone operators was 12.8 seconds and in control group was 16.8 seconds. Jitter, pitch pertubation quotient (PPQ), shimmer and amplitude pertubation quotient (ASQ) were significantly increased in subjective group than control group, but there is no difference between two group in fundamental frequency and noise to harmonic ratio. Conclusion : Untrained professional voice user needs professional career guidance and counseling. And when we manage the untrained professional voice user, we should consider specific occupational, personal and environmental factors as well as laryngeal factors.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권1호
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• pp.6-10
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• 2008

In this paper, we introduce the concept of fuzzy (r, s)-adherence points, fuzzy (r, s)-accumulation points and fuzzy (r, s)-derived sets in double fuzzy topology. We investigate some of their properties. The relationship with double fuzzy closure operator was studied.

• 대한산업공학회지
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• 제43권3호
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• pp.176-183
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• 2017

In recent years, studies about multitasking becomes more important. During multitasking, operators can feel frustration when they are interrupted during the task and frustration can affect operator's emotional state and performance. However there is no research on measuring the frustration quantitatively in multitasking environment. In this paper, we suggested quantitative measurement of frustration during multitasking. In order to measure the frustration, we made a mathematical representation with emotional decay model and the initial intensity of frustration based on cognitive closure theory. The amount of initial intensity could be represented as the ratio of actual remaining time to expected remaining time. By the experiment, we measured the frustration during the experiment and compared this values with values of frustration dimension of NASA-TLX. Finally we got the linear regression model with a good accuracy ($R^2=0.986$). This study contributes to measuring the emotion quantitatively by the relation of expected and actual remaining time in multitasking environment.

• 한국지능시스템학회논문지
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• 제23권1호
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• pp.80-86
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• 2013

We give a new definition of ordinary smooth closure and ordinary smooth interior of an ordinary subset in an ordinary smooth topological space which have almost all the properties of the corresponding operators in a classical topological space. As a consequence of these definitions we reduce the additional hypotheses in the results of [1] and also generalize several properties of the types of compactness in [1].

• 대한수학회보
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• 제55권5호
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• pp.1351-1370
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• 2018

In the first part of this paper we show that, under some conditions, a polynomially demicompact operator can be demicompact. An example involving the Caputo fractional derivative of order ${\alpha}$ is provided. Furthermore, we give a refinement of the left and the right Weyl essential spectra of a closed linear operator involving the class of demicompact ones. In the second part of this work we provide some sufficient conditions on the inputs of a closable block operator matrix, with domain consisting of vectors which satisfy certain conditions, to ensure the demicompactness of its closure. Moreover, we apply the obtained results to determine the essential spectra of this operator.

• 대한수학회보
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• 제43권4호
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• pp.671-677
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• 2006

Let $A, B{\in}B(H)$ be Hilbert space contractions, and let ${\Delta}_{AB}$ be the elementary operator ${\Delta}_{AB}:X{\rightarrow}AXB-X$. A number of conditions which are equivalent to '${\Delta}_{AB}$ has closed range' are proved.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1997년도 춘계학술대회 학술발표 논문집
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• pp.47-51
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• 1997

In this paper, certain fuzzy semi-separation axioms are studied in terms of the notions of quasi-coincidence, fuzzy semi-q-neigborhoods and fuzzy semi-$\theta$-closure operators. Fuzzy semi-T2, fuzzy semi-Urysohn and fuzzy s-regular spaces are defined, and fuzzy spaces satisfying these axioms are characterized.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제25권4호
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• pp.243-252
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• 2018

In this paper, we study the sequentially open and closed subsets of sequential topological groups determined by sequentially continuous group homomorphism. In particular, we investigate the sequentially openness (closedness) and sequentially compactness of subsets of sequential topological groups by the aid of sequentially continuity, sequentially interior or closure operators. Moreover, we explore subgroup and sequential quotient group of a sequential topological group.