• The Pure and Applied Mathematics
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• v.22 no.1
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• pp.25-34
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• 2015

In this paper we characterize the isogonal and isotomic conjugates of conic. Every conic can be expressed by a quadratic rational B$\acute{e}$zier curve having control polygon $b_0b_1b_2$ with weight w > 0. We show that the isotomic conjugate of parabola and hyperbola with respect to ${\Delta}b_0b_1b_2$ is ellipse, and that the isotomic conjugate of ellipse with the weight $w={\frac{1}{2}}$ is identical. We also find all cases of the isogonal conjugate of conic with respect to ${\Delta}b_0b_1b_2$. Our characterizations are derived easily due to the expression of conic by the quadratic rational B$\acute{e}$ezier curve in standard form.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.3
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• pp.41-48
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• 2012

In this paper, we propose a method of edge detection for noisy image. The proposed method uses a progressive filter for noise reduction and a Sobel operator for edge detection. The progressive filter combines a median filter and a modified rational filter. The proposed method for noise reduction adjusts rational filter direction according to an edge in the image which is obtained by median filtering. Our method effectively attenuates the noise while preserving the image details. Edge detection is performed by a Sobel operator. This operator can be implemented by integer operation and is therefore relatively fast. Our proposed method not only preserves edge, but also reduces noise in uniform region. Thus, edge detection is well performed. Our proposed method could improve results using further developed Sobel operator. Experimental results show that our proposed method has better edge detection with correct positions than those by existing median and rational filtering methods for noisy image.

• Journal of the Korean Statistical Society
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• v.27 no.2
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• pp.237-249
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• 1998

Process adjustment has been widely used in production processes in order to set the output characteristic as close as to the target. Box and Kramer(1992) developed a feedback adjustment control procedure for process adjustment. We generalize their procedure by using a rational subgrouping of sequential observations. In this paper the feedback control rule of the rational subgrouping is proposed and the overall expected cost is evaluated. Also properties of the proposed control scheme are illustrated and compared to Box and Kramer's in the context of the expected cost.

• Honam Mathematical Journal
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• v.41 no.2
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• pp.421-433
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• 2019

Let n denote an integer greater than 2 and let c denote a nonzero complex number. In this paper, we introduce a family of elements of the rational Cherednik algebra $H^{sl_n}(c)$ of type $sl_n$, which are analogous to the Dunkl-Cherednik elements of the rational Cherednik algebra $H^{gl_n}(c)$ of type $gl_n$. We also introduce the raising and lowering element of $H^{sl_n}(c)$ which are useful in the representation theory of the algebra $H^{sl_n}(c)$, and provide simple results related to these elements.

• Communications of the Korean Mathematical Society
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• v.37 no.1
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• pp.259-267
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• 2022

We use L_∞ models to compute the rational homotopy type of the mapping space of the component of the natural inclusion i_n,k : ℂPⁿ ↪ ℂP^n+k between complex projective spaces and show that it has the rational homotopy type of a product of odd dimensional spheres and a complex projective space. We also characterize the mapping aut₁ ℂPⁿ → map(ℂPⁿ, ℂP^n+k; i_n,k) and the resulting G-sequence.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.1
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• pp.194-204
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• 1997

In this paper, we consider the rational approximation of multiple input delay systems. The method of computing Hankel singular values and vectors is firstly introduced, where explicitly shows the structure of the corresponding Hankel singular vectors. Secondly, rational approximants are obtained from output nor- mal relizations, which are constructed by Hankel singular values and vectors. As a result, it is shown that rational approximants by output normal realization preserve intrinsic properties of time delay systems than Pad'e approximants.

• Journal of Acupuncture Research
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• v.30 no.3
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• pp.27-38
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• 2013

Objectives : This study was designed to evaluate patient satisfaction of Korean medicine therapy using treatment tool by psychological type. Methods : 48 subjects were participated in this study. Before a treatment, we analyzed a patient's phychological type first by using a questionnaire. And then we divided 3 groups which were called a rational sympathy module group, emotional sympathy module group, control group. Manner of medical consultation according to patient's phychological type was carried out in all groups. After all treatment, we conducted a survey about medical service perception index, patient happiness index, medical satisfaction index. To evaluate a satisfaction degree, we analyzed results of survey statistically. Results : The results of the analysis, both rational sympathy module group and emotional sympathy module group got a higher score than control group statistical significantly on medical service perception index. Emotional sympathy module group got a higher score than control group statistical significantly on patient happiness index and medical satisfaction index. But rational sympathy module group only had a higher tendency than control group on patient happiness index and medical satisfaction index. Emotional sympathy module group got a higher score than rational sympathy module group on medical service perception index, patient happiness index and medical satisfaction index. Conclusions : Korean medicine therapy using treatment tool by psychological type consisted of patient's phychological type questionnaire and manner of medical consultation could improve a patient's satisfaction. It was more effective in emotional sympathy module group than rational sympathy module group.

• Journal of Korean Philosophical Society
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• v.147
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• pp.59-76
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• 2018

What are the conditions make a being x a moral agent? Can an artifact be moral agent? A moral agent is considered to be a rational being capable of distinguishing between right and wrong. This study critically analyzed Davidson's position on the condition of the rational being and argued that the network of beliefs with propositional attitude and the beliefs as their background cannot be a requisite for the rational being. Later, it proves that the conditions proposed by $Proke{\check{s}}ov{\acute{a}}$ are merely paratactically listed superficial elements. The moral agent in this study includes the rational agent and it is proven that the strong first person viewpoint is the necessary and sufficient condition for rational agent and moral agent. In conclusion, it suggested a the sketch of moderate skepticism which sets the tentative limit on the agent potential in an artifact by suggesting conditions for moral agent instead of intense skepticism that strongly denies the potential as the moral agent.

• Journal of Service Research and Studies
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• v.10 no.3
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• pp.103-118
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• 2020

Chinese economic growth and Chinese adoption of foreign cultures have changed varied phenomena, consumption patterns and consumer life-styles, in particular. In order to understand behavior of Chinese consumers, it is critical to explore their lifestyles and its effects on their purchase behavior. For attaining this goal, our research classifies Chinese consumer lifestyles related to cosmetics, into four types: brand oriented, price sensitive, rational consumption, and impulse buying. The research further analyzes the effects of consumer lifestyles on perceived value, satisfaction, and purchase intention in each case of skin care cosmetics and make-up cosmetics. Significant difference are found in perceived value, satisfaction, and purchase intention of skin care cosmetics exists between brand-oriented type and rational consumption type. This is also the case between rational consumption type and impulse buying type. Purchase intention is only found to be different between rational consumption type and price sensitive type. In case of make-up cosmetics, significant differences in perceived value, satisfaction, and purchase intention in the pairs of brand-oriented type and rational consumption type, rational consumption type and impulse buying type, and rational consumption type and price sensitive type. This implies rational consumption type should be more appropriate target consumers in the Chinese cosmetics market.

• Journal of Korea Water Resources Association
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• v.52 no.6
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• pp.411-420
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• 2019

The objective of this study is to evaluate the appropriateness of methodology for designing urban sewer system using a rational method-based model, Makesw and an urban runoff model, SWMM. The Gunja basin was selected as a study area and precipitation, runoff, vegetation, soil, imperviousness data were used to estimate floods. The appropriateness of methodology was evaluated based on comparison analysis between floods estimated from Makesw and SWMM. The comparison analysis was conducted between floods estimated from Makesw and SWMM, which were simulated using design rainfall and measured rainfall from past inundation events. The comparison results showed that in the case of design rainfall, the rational method-based floods were larger than that based on SWMM in all main lines. However in several branch lines, the rational method-based floods were smaller than thoes based on SWMM. In addition, for the case of measured rainfall from past inundation events, it was easily to find the main and branch lines where the rational method-based floods were smaller than SWMM based ones. Especially, the lines where rational method-based floods were underestimated, were mostly main, $1^{st}$, $2^{nd}$ lines. It was concluded that the rational method-based results were not conservative. Based on rational method (steady flow analysis) and SWMM (unsteady flow analysis), the more conservative results the method provides, the more highly it is recommended to use in designing an urban sewer system.