• Nonlinear Functional Analysis and Applications
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• v.27 no.4
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• pp.797-805
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• 2022

Let P(z) be a polynomial of degree n. A well-known inequality due to S. Bernstein states that if P ∈ P_n, then $$\max_{{\mid}z{\mid}=1}\,{\mid}P^{\prime}(z){\mid}\,{\leq}n\,\max_{{\mid}z{\mid}=1}\,{\mid}P(z){\mid}$$. In this paper, we establish some extensions and refinements of the above inequality to polar derivative and some other well-known inequalities concerning the polynomials and their ordinary derivatives.

• Journal of the Korean Mathematical Society
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• v.60 no.3
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• pp.683-694
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• 2023

Let a be an ideal of 𝔞 commutative noetherian ring R. We give some descriptions of the 𝔞-depth of 𝔞-relative Cohen-Macaulay modules by cohomological dimensions, and study how relative Cohen-Macaulayness behaves under flat extensions. As applications, the perseverance of relative Cohen-Macaulayness in a polynomial ring, formal power series ring and completion are given.

• Kyungpook Mathematical Journal
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• v.63 no.4
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• pp.709-718
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• 2023

The inner automorphism groups of quandles are related to the classification problem of quandles. The inner automorphism group of a quandle is generated by inner automorphisms which are presented by columns in the operation table of the quandle. In this paper, we describe inner automorphisms of an abelian extension of a quandle by expressing columns of the operation table of the extended quandle as columns of the operation table of the original quandle. Such a description will be helpful in studying inner automorphism groups of abelian extensions of quandles.

• Journal of the Korean Mathematical Society
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• v.61 no.2
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• pp.341-356
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• 2024

In this paper, apply the regularities of the fractional Poisson kernels, we establish the Sobolev type trace inequalities of homogeneous Besov spaces, which are invariant under the conformal transforms. Also, by the aid of the Carleson measure characterizations of Q type spaces, the local version of Sobolev trace inequalities are obtained.

• Journal of Broadcast Engineering
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• v.20 no.2
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• pp.224-237
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• 2015

In this paper, we introduce the fast decoding method with the SIMD (Single Instruction Multiple Data) instructions for HEVC RExt (High Efficiency Video Coding Range Extensions). Several tools of HEVC RExt such as intra prediction, interpolation, inverse-quantization, inverse-transform, and clipping modules can be classified as the proper modules for applying the SIMD instructions. In consideration of bit-depth increasement of RExt, intra prediction, interpolation, inverse-quantization, inverse-transform, and clipping modules are accelerated by SSE (Streaming SIMD Extension) instructions. In addition, we propose effective implementations for interpolation filter, inverse-quantization, and clipping modules by utilizing a set of AVX2 (Advanced Vector eXtension 2) instructions that can use 256 bits register. The evaluation of the proposed methods were performed on the private HEVC RExt decoder developed based on HM 16.0. The experimental results show that the developed RExt decoder reduces 12% average decoding time, compared with the conventional sequential method.

• KIISE Transactions on Computing Practices
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• v.22 no.10
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• pp.537-545
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• 2016

Demand for text arranged in a circular shape is increasing as devices with round display such as smart watches are now being actively released. Data visualization field is receiving a lot of attention as the era of big data evolves. However, current web standard does not support the drawing of circular text. Therefore, the objective of this study was to extend CSS3 specifications to have circular text layout in web documents. In addition, we implemented a preprocessor so that contents made with CSS3 extensions could be shown in existing browsers. To confirm the wide expression range of CSS3 extension, we prepared some sample contents and analyzed them.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.543-548
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• 2016

Public electronic certificates, as an important means for identification, have been used as the main economic transactions, including banking, e-government, e-commerce. identification. However, damage cases of certificates have been increased by Illegally issued and by hacking practices. Also the users have a difficult in ensuring that their certificates when and where to use. Therefore, the proposed system gives the organization code for the Institutions using OCSP services in advance, the organization code embedded in extensions of OCSP request message structure when institutions ask the validation of certificate to CA(Certificate Authority). Also, OCSP server can extract the organization code from OCSP request message, confirm the institution, and record it in certificate history management table of DB. In this paper, we presented a system that could determine the certificate history check using OCSP service, public electronic certificate validation service, and implemented to prevent and cope immediately with financial incidents.

• Journal of the Korea Society of Computer and Information
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• v.16 no.12
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• pp.33-41
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• 2011

From Complicated graph structures, duplicated operations can be executed and the operations give low efficiency. In this paper, we propose an efficient graph mining algorithm of minimizing the extension of duplicated graph patterns in which the priorities of cyclic edges are considered. In our approach, the cyclic edges with lower priorities are first extended and so duplicated extensions can be reduced. For performance test, we implement our algorithm and compare our algorithm with a state of the art, Gaston algorithm. Finally, We show that ours outperforms Gaston algorithm.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.251-258
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• 2017

Most malware, including Ransomware, is built for the Windows operating system. This is because it is more harmful to target an operating system with a high share. But in recent years, MacOS's operating system share has steadily increased. As people become more and more used, the number of malicious code running on the MacOS operating system is increasing. Ransomware has been known to Korea since 2015, and damage cases are gradually increasing. MacOS is no longer free from Ransomware, as Ransomware for MacOS was discovered in March 2016. In order to cope with future Ransomware, this paper used Ransomware's modified file extension to detect Ransomware. We have studied how to detect and block Ransomware processes by distinguishing between extensions changed by the user and extensions changed by the Ransomware process.

• The Research Journal of the Costume Culture
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• v.23 no.1
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• pp.102-116
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• 2015

This study aimed to identify the effects of fashion brand extensions types, preannouncing and consumers' regulatory focus on preference towards extension products. To that end, the study used a 2 (fashion brand extension types: similar vs. non-similar) ${\times}2$ (preannouncing: near preannouncing vs. far preannouncing) ${\times}2$ (regulatory focus: promotion focus vs. prevention focus) three mixed elements. The subjects of the study were 280 men and women in their 20~40s living in Seoul and Chungnam province and total of 229 data were analyzed. Data were analysed with SPSS 19.0 program and three-way ANOVA, simple interaction effects and simple main effects analysis were conducted. The results of this study are as follows: First there were significant differences in preference based on fashion brand extension types and preannouncing. Second, there were significant interaction effects in preference between extension types of fashion brand and regulatory focus. But there was no difference in preference toward extension products according to types of preannouncing and regulatory focus. Lastly, fashion brand extension types, preannouncing and regulatory focus showed significant interaction effects on preference. Thus even in cases of non-similar brand extensions which carry more risk of failing, the appropriate marketing communication strategies such as preannouncing will result in brand preference. Also marketing activities should be comprehensive and strategical based on consumers' tendencies in order to derive positive evaluations.