• Journal of Information Technology Applications and Management
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• v.13 no.1
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• pp.39-66
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• 2006

In a few years, a variety of mobile devices are expected to be utilized as a necessity for business as well as personal communications. Thus it is needed to conduct a comprehensive study on the acceptance of mobile devices in the mature market like Korea. This paper develops an extended technology acceptance model by including functional attributes of cellular phone and examines the determinant factors causing accepting cellular phones. Our empirical analysis through the internet survey shows that 1) among the determinant factors, perceived usefulness, perceived enjoyment or fun, and social pressure have positive direct impacts on the intention of accepting cellular phone, and 2) functional attributes of cellular phone affect the determinant factors differently.

• Communications of the Korean Mathematical Society
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• v.36 no.4
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• pp.715-727
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• 2021

In this paper, we give some results an upper bound of Hankel determinant of H₂(1) for the classes of 𝓝 (𝜶). We get a sharp upper bound for H₂(1) = c₃ - c²₂ for 𝓝 (𝜶) by adding z₁, z₂, …, z_n zeros of f(z) which are different than zero. Moreover, in a class of analytic functions on the unit disc, assuming the existence of angular limit on the boundary point, the estimations below of the modulus of angular derivative have been obtained. Finally, the sharpness of the inequalities obtained in the presented theorems are proved.

• Korean Journal of Mathematics
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• v.28 no.4
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• pp.699-715
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• 2020

In this paper, we give estimates of the Hankel determinant H₂(1) in a novel class 𝓝 (𝜀) of analytical functions in the unit disc. In addition, the relation between the Fekete-Szegö function H₂(1) and the module of the angular derivative of the analytical function p(z) at a boundary point b of the unit disk will be given. In this association, the coefficients in the Hankel determinant b₂, b₃ and b₄ will be taken into consideration. Moreover, in a class of analytic functions on the unit disc, assuming the existence of angular limit on the boundary point, the estimations below of the modulus of angular derivative have been obtained.

• Bulletin of the Korean Mathematical Society
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• v.60 no.5
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• pp.1365-1374
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• 2023

Let F be a periodic singular fiber of genus g with dual fiber F^*, and let T (resp. T^*) be the set of the components of F (resp. F^*) by removing one component with multiplicity one. We give a formula to compute the determinant | det T | of the intersect form of T. As a consequence, we prove that | det T | = | det T^*|. As an application, we compute the Mordell-Weil group of a fibration f : S → ℙ¹ of genus 2 with two singular fibers.

• Communications of the Korean Mathematical Society
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• v.38 no.2
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• pp.341-354
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• 2023

In this article, an alternating Fibonacci sequence is defined from a second-order linear homogeneous recurrence relation with constant coefficients. Then, the determinant, inverse, and eigenvalues of the circulant matrices with entries in the first row having the formation of the sequence are formulated explicitly in a simple way. In this study, the method for deriving the formulation of the determinant and inverse is simply using traditional elementary row or column operations. For the eigenvalues, the known formulation from the case of general circulant matrices is simplified by considering the specialty of the sequence and using cyclic group properties. We also propose algorithms for the formulation to show how efficient the computations are.

• The Pure and Applied Mathematics
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• v.31 no.2
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• pp.201-216
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• 2024

The aim of this paper is to study a new and unified class 𝓡^α_Cosh of analytic functions associated with cosine hyperbolic function in the open unit disc E = {z ∈ ℂ : |z| < 1}. Some interesting properties of this class such as initial coefficient bounds, Fekete-Szegö inequality, second Hankel determinant, Zalcman inequality and third Hankel determinant have been established. Furthermore, these results have also been studied for two-fold and three-fold symmetric functions.

• Journal of Preventive Medicine and Public Health
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• v.28 no.1 s.49
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• pp.153-174
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• 1995

This study was conducted to examine the determinant factors for expenditure of the medical insurance program for self-employeds based on the analysis of 1991 'The Medical Insurance Program for Self-Employeds Statistical Yearbook', and also similar yearbooks in the metropolitan and other provinces. The major findings are as follows : We have divided benefits into these four components such as the utilization rate for out-patients, expenses per claim for out-patients as paid by the insurer, utilization rate for in-patients, and the expenses per claim for in-patients as paid by the insurer, in order to examine the determinant factors for it. The results of the study revealed the following findings, in urban areas, the supply of medical care had more influence on the benefits than other demographic and economic variables, while, in county areas, both the supply of medical care and the rate of those aged over 65 affected the provision of benefits. The determinant factors for financial balance of the medical insurance program for self-employeds are, first, the determinant factor for administrative expenses was the number of households. The more the number of households, the less the administrative expenses per the insured. This shows that the economy of scale is being. And so, the administrative district must be taken into consideration in the incorporation of small regional medical societies and should be re-organized for more efficient management. Second, in urban areas, the supply of medical care had more influence on utilization rate and expenses per claim as paid by insurer, and therefore it is necessary to control it. In county areas, the supply of medical care and the rate of those aged over 65 raised the utilization rate and expenses per claim as paid by insurer. For the financial stability of county areas, a common fund for medical care for the aged and expansion of finance stabilization fund would be necessary. But, in county areas, it would be unnecessary to control the supply of medical care because it was much more insufficient than in urban areas. The vitalization of public health facilities must be carried out in county areas, for they reduced benefits. Sice the more insured in a single household, the less the utilization of the medical insurance program, benefits for habilitation at home should be given consideration. The law of majority and the economy of scale were applied here, and therefore the incorporation of regional medical societies must be taken into consideration. In integrating regional medical societies, it would be absolutely necessary to review the structural differences among all regional medical societies, the medical demand of each region, and also the local characteristics of each region.

• Bulletin of the Korean Mathematical Society
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• v.48 no.6
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• pp.1219-1224
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• 2011

In this paper we give a determinant formula for congruent zeta functions of real Abelian function fields. We also give some example of congruent zeta functions when the conductor of real Abelian function field is monic irreducible.

• The Pure and Applied Mathematics
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• v.18 no.3
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• pp.269-274
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• 2011

We investigate the divisor class group of surfaces over finite fields. For some surfaces the divisor class group depends on the characteristic of the field. We calculate the determinant of a matrix which will provide an information about the divisor class group of the surfaces.

• Communications for Statistical Applications and Methods
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• v.2 no.1
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• pp.89-98
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• 1995

This paper presents the interesting properties of a certain patterned matrix that plays an significant role in the multi-way balanced designs. The necessary and sufficient condition on the existence of the inverse of the patterned matrix and its determinant are described. In special cases of the pattermed matrix, explicit formulas for its inverse, determinant and the characteristic equation are obtained.