• Kyungpook Mathematical Journal
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• v.54 no.1
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• pp.31-41
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• 2014

In this paper criterion for $L_1$-convergence of a certain cosine sums with quasi hyper-convex coefficients is obtained.

• Kyungpook Mathematical Journal
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• v.47 no.3
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• pp.323-328
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• 2007

In this paper, we extend the result of Ram [3] and also study the $L^1$-convergence of the $r^{th}$ derivative of cosine series.

• Communications of the Korean Mathematical Society
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• v.39 no.2
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• pp.407-420
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• 2024

In this paper, we investigate some geometric properties of starlikeness connected with the hyperbolic cosine functions defined in the open unit disk. In particular, for the class of such starlike hyperbolic cosine functions, we determine the lower bounds of partial sums, Briot-Bouquet differential subordination associated with Bernardi integral operator, and bounds on some third Hankel determinants containing initial coefficients.

• Kyungpook Mathematical Journal
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• v.45 no.1
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• pp.73-85
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• 2005

In this paper a criterion for $L^1-convergence$ of a new modified sine sums is obtained by using $Ces{\grave{a}}ro$ means of integral and non-integral orders.

• Kyungpook Mathematical Journal
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• v.19 no.2
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• pp.257-260
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• 1979

We show that the condition S of Sidon is sufficient for the integrability of the limit of Rees-$Stanojevi{\acute{c}$ cosine sums $g_n(x)={\frac{1}{2}}{\limits\sum^{n}_{k=0}}{\Delta}a_k+{\limits\sum^{n}_{k=1}}{\limits\sum^{n}_{j=k}}{\Delta}a_j\;cos\;kx$.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.9 no.1
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• pp.9-16
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• 2005

The random signals defined as sums of the single frequency sinusoidal signals with random amplitudes and random phases or equivalently sums of functions obtained by adding a Sine and a Cosine function with random amplitudes, are used in the double randomization method for the Monte Carlo solution of the turbulent systems. We show that these random signals can be used for studying the properties of the Johnson noise by proving that constant multiples of these signals with uniformly distributed frequencies in a fixed frequency band satisfy the properties of the Gaussian white noise.

• Journal of the Korean Society for Library and Information Science
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• v.39 no.3
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• pp.139-163
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• 2005

Various corpus-based approaches, rhetorical roles of discourse structure, and unifications of similar sentences were applied to construct the automatic Ext/Sums(extracts and summaries). Rhetorical roles of sentences like objective, method, background, result, conclusion, etc. for making elastic Ext/Sums were established and extraction engines according to respective role were prepared. The $90\%$ of Success rate in extracting the important sentences of sample articles was accomplished. Rearranging the selected sentences, it used unification of similar sentences using the cosine coefficient equation, deletion of unnecessary modification and insertion clauses, junction of short sentences, and connection of sentences able to link. They suggest the methods applying rhetorical roles of sentences, meaning and signature of noun and verb in clauses, and cue words and location will be researched to construct the more effective Ext/Sums.