• Journal of the Korean Society for Precision Engineering
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• v.20 no.7
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• pp.208-216
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• 2003

In this paper, a two-dimensional electroelastic analysis is performed on a piezoelectric material with an open crack. The approach of Lekhnitskii's complex potential functions is used in the derivation and Bueckner's weight function theory is extended to piezoelectric materials. The stress intensity factors and the electric displacement intensity factor are calculated by the weight function theory.

• East Asian mathematical journal
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• v.17 no.2
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• pp.175-183
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• 2001

The main object of this paper is to investigate several majorization problems involving two subclasses $S_{p,q}(\gamma)$ and $C_{p,q}(\gamma)$ of p-valently starlike and p-valently convex functions of complex order ${\gamma}{\neq}0$ in the open unit disk $\mathbb{u}$. Relevant connections of the results presented here with those given by earlier workers on the subject are also indicated.

• Honam Mathematical Journal
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• v.40 no.3
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• pp.391-400
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• 2018

The object of this paper to construct a new class $$A^m_{{\mu},{\lambda},{\delta}}({\alpha},{\beta},{\gamma},t,{\Psi})$$ of bi-univalent functions of complex order defined in the open unit disc. The second and the third coefficients of the Taylor-Maclaurin series for functions in the new subclass are determined. Several special consequences of the results are also indicated.

• Kyungpook Mathematical Journal
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• v.60 no.4
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• pp.797-803
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• 2020

The Brück conjecture is still open for an entire function f with hyper order of no less than 1/2, which is not an integer. In this paper, it is proved that the hyper order of solutions of a linear complex differential equation that is related to the Brüuck Conjecture is infinite. The results show that the conjecture holds in a special case when the hyper order of f is 1/2.

• The Mathematical Education
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• v.55 no.2
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• pp.209-232
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• 2016

This study analyzed the process of steps in a program introducing Renzulli's enrichment triad model and various levels of posing open-ended problems of those who participated in the program for mathematics-gifted elementary students. As results, participants showed their abilities of problem posing related to real life in a program introducing Renzulli's enrichment triad model. From eighteen mathematical responses, gifted students were generally outstanding in terms of producing problems that demonstrated high quality completion, communication, and solvability. Amongst these responses from fifteen open-ended problems, all of which showed that the level of students' ability to devise questions was varied in terms of the problems' openness (varied possible outcomes), complexity, and relevance. Meanwhile, some of them didn't show their ability of composing problem with concepts, principle and rules in complex level. In addition, there are high or very high correlations among factors of mathematical problems themselves as well as open-ended problems themselves, and between mathematical problems and open-ended problems. In particular, factors of mathematical problems such as completion, communication, and solvability showed very high correlation with relevance of the problems' openness perspectives.

• Journal of Korean Association for Spatial Structures
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• v.21 no.1
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• pp.41-49
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• 2021

In this study the characteristics of wind pressure that are depending on the open type of retractable dome roof were analyzed according to the wind pressure coefficient and wind pressure spectrum. The analysis results showed that the open type and shape of the roof both had a significant impact on the wind pressure changing. In case of the edge to center open type, the wind pressure has not changed much because of the complex turbulence of flow and open area. On the other hand, in case of the center to edge open type, it has confirmed that wind pressure increases due to the separation of flow in windward and open area.

• Journal of the Korean housing association
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• v.14 no.6
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• pp.165-172
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• 2003

With the rate of spread of motors rapidly increased, but parking difficulties in an apartment complex was aggravated due to an insufficient parking lot. Visual interference on residential environment, various kinds of pollution and noise, decrease of open space in an apartment complex are also causes of parking difficulties. Therefore, this study is to suggest a theory of desirable direction for planning of the parking space by studying psychological characteristics of users' behaviors by the type of the circulation of motors and pedestrians. Consideration on the present situation, real conditions of underground parking space and the consciousness and parking habit of residents, the most important problem is required in this study.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.201-207
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• 2007

As the power industry moves towards open competition, there has been a need for methodology to evaluate distribution power system reliability by using customer interruption costs, particularly in power supply zones under the competitive electricity market. This paper presents an algorithm to evaluate system average interruption duration index, expected energy not supplied, and system outage cost taking into consideration failure rate of the distribution facility and industrial customer interruption cost. Also, to apply this algorithm to evaluate system outage cost presented in this paper, the distribution arrangement of a dual supply system consisting of mostly high voltage customers in an industrial complex in Korea is used as a sample case study. Finally, evaluation results of system interruption cost, system average interruption duration index, and expected energy not supplied in the sample industrial complex area are shown in detail.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.2
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• pp.235-251
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• 1997

A numerical simulation on the combined natural convection and radiation is carried out in a partially open rectangular enclosure with a heater by using the finite volume and the S-8 discrete ordinate methods. The fluid inside the enclosure is considered as an absorbing, emitting and anisotropic scattering media. The heater causes a natural circulation of the fluid (10$^{5}$ $^{9}$ ) which results in significant in-flow of the ambient cold fluid through the partially open wall. Comparing the results of pure convection with those of the combined convection- radiation, the combined heat transfer results with small Planck numbers (P$_{l}$ <1.0) show much stronger circulation than those of the pure convection, and the fluid circulation is more evident for larger Rayleigh numbers. When one of three radiative properties - the medium absorption coefficient, the wall reflectivity, and the scattering albedo - increases, the fluid circulation and the heat transfer in the enclosure are reduced. The location of the heater and the open ratio of the right wall are also shown to affect the fluid circulation and heat transfer significantly. However, the anisotropy of the scattering phase function is shown to be unimportant for the fluid circulation and heat transfer within the enclosure considered in this study.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.167-174
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• 2009

A Tile Map Service is a regular map service that has been enhanced to serve maps very quickly using a cache of static images. The map cache is a directory that contains image tiles of a map extent at specific scale levels. Returning a tile from the cache takes the server much less time than drawing the map image on demand. Use of a Tile Map Service can dramatically improve the time that clients take to display complex base-maps. Using Tile Map Services thus eliminate the need to trade quality for performance. This study provides a way to construct Tile Map Service System using Open Source GIS. We used GDAL(Geospatial Data Abstraction Library) which is one of the Open Source GIS Softwares to make Tile Map Image and OpenLayers to publish Web Page. Moreover, We conducted a performance test on Tile Map System and Dynamic Map System and evaluated the results of it. As a result, the proposed method makes it easier to construct high performance Tile Map Service using Open Source GIS without commercial products.