• Title/Summary/Keyword: General number theory

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Changes in housing characteristics through residential mobility (주거이동을 통한 가족의 주거환경 변화 조정)

  • JaeSoonCho
    • Journal of the Korean housing association
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    • v.3 no.1
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    • pp.1-19
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    • 1992
  • The primary objective of this study is to find out how housing characteristics have been changed through a recent move. Two hundreds and thrity households in Cheongju City who made a move during 1990 are selected for the empherical study. The findings show that almost families moved to the dwelling with similar or better conditions than the previous ones. The patterns of housing characteristics changed through a move play the role as an intervening variable between family characteristics and changes in housing satisfaction. Also, the results in general support the concepts of housing adjustment theory. There is a small number of low income families who moved to dwelling with worse conditions. Presumably constraints might prevent their housing adjustment behavior.

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An Empirical Investigation for EIS Utilization:On the Basis of TAM (중역정보 시스템의 활용에 관한 실증연구)

  • Kim, Jong-Weon
    • The Journal of Information Systems
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    • v.6 no.1
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    • pp.257-291
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    • 1997
  • Today, executives in the company operate their organizations under highly competitive environments with dynamic technological, economic, and political changes. Under these new environment changes, they play the important role in establishing the future directions and strategic orientations of organizations. In general, executive information systems (EIS) are designed to support these roles of executives. They can help executives access and use the information they require about the organization's internal and external environments. In spite of such potential EIS support for executives, only a limited number of empirical studies have been published in this area. by employing a well-established theory of computer usage behavior (Technology Acceptance Model : TAM), this study systematically investigates the key factors in the successful utilization of an EIS. The empirical results from this study may prove useful for both IS researchers and practitioners.

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Radiation Pattern of SH Waves Generated by an Orientation-adjustable Patch-type Magnetostrictive Transducer (조향 자기변형 트랜스듀서의 전단파 방사 패턴)

  • Jeon, Byung-Chul;Lee, Ju-Seung;Cho, Seung-Hyun;Kim, Yoon-Young
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.807-808
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    • 2008
  • This is concerned with the radiation pattern of elastic waves in a plate generated by an orientation-adjustable patch-type magnetostrictive transducer. In general, not only the Lamb waves but also shear horizontal (SH) waves are produced by the deformation of the circular magnetostrictive patch bonded to a plate. Among the two types of waves, this paper investigates the radiation patterns of SH waves. A number of experimental results are presented. They are also accurately predicted by a theory developed by the present authors. Experimental findings were explained by a theoretical analysis.

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Thermomechanical buckling of rectangular, shear-deformable, composite laminated plates

  • Ge, Y.S.;Yuan, W.X.;Dawe, D.J.
    • Structural Engineering and Mechanics
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    • v.13 no.4
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    • pp.411-428
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    • 2002
  • The B-spline finite strip method is developed for the prediction of the buckling of rectangular composite laminated plates under the combined action of applied uniaxial mechanical stress and increasing temperature. The analysis is conducted in two stages, namely an in-plane stress analysis in the pre-buckling stage to determine the pre-buckling stresses, followed by a buckling analysis using these determined stresses. The buckling analysis is based on the use of first-order shear deformation plate theory. The permitted lay-up of the laminates is quite general, within the constraint that the plate remains flat prior to buckling, and a wide range of boundary conditions can be accommodated. A number of applications is described and comparison of the results generated using the finite strip method is made with the results of previous studies.

NEW SERIES IDENTITIES FOR ${\frac{1}{\Pi}}$

  • Awad, Mohammed M.;Mohammed, Asmaa O.;Rakha, Medhat A.;Rathie, Arjun K.
    • Communications of the Korean Mathematical Society
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    • v.32 no.4
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    • pp.865-874
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    • 2017
  • In the theory of hypergeometric and generalized hypergeometric series, classical summation theorems have been found interesting applications in obtaining various series identities for ${\Pi}$, ${\Pi}^2$ and ${\frac{1}{\Pi}}$. The aim of this research paper is to provide twelve general formulas for ${\frac{1}{\Pi}}$. On specializing the parameters, a large number of very interesting series identities for ${\frac{1}{\Pi}}$ not previously appeared in the literature have been obtained. Also, several other results for multiples of ${\Pi}$, ${\Pi}^2$, ${\frac{1}{{\Pi}^2}}$, ${\frac{1}{{\Pi}^3}}$ and ${\frac{1}{\sqrt{\Pi}}}$ have been obtained. The results are established with the help of the extensions of classical Gauss's summation theorem available in the literature.

TRACE EXPRESSION OF r-TH ROOT OVER FINITE FIELD

  • Cho, Gook Hwa;Koo, Namhun;Kwon, Soonhak
    • Journal of the Korean Mathematical Society
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    • v.57 no.4
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    • pp.1019-1030
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    • 2020
  • Efficient computation of r-th root in 𝔽q has many applications in computational number theory and many other related areas. We present a new r-th root formula which generalizes Müller's result on square root, and which provides a possible improvement of the Cipolla-Lehmer type algorithms for general case. More precisely, for given r-th power c ∈ 𝔽q, we show that there exists α ∈ 𝔽qr such that $$Tr{\left(\begin{array}{cccc}{{\alpha}^{{\frac{({\sum}_{i=0}^{r-1}\;q^i)-r}{r^2}}}\atop{\text{ }}}\end{array}\right)}^r=c,$$ where $Tr({\alpha})={\alpha}+{\alpha}^q+{\alpha}^{q^2}+{\cdots}+{\alpha}^{q^{r-1}}$ and α is a root of certain irreducible polynomial of degree r over 𝔽q.

Optimum Vibration Angle for Transporting Granular Materials on Linear Conveyors

  • Keraita, James Nyambega
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.2
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    • pp.3-7
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    • 2008
  • Vibratory conveyors are widely used in industry to transport granular materials and products. A theoretical point mass model for vibratory conveying was studied. The results agreed well with experimental observations. The model theory included the resting, sliding and flight states of the material. Each state was considered separately when determining the equations of motion. For the coefficients of restitution, values of zero for the normal component and 0.8 for the tangential component were found to be appropriate for modeling the collisions of the granular particles with the conveying surface. The vibration angle had a large influence on the mode and rate of transport. There was an optimum vibration angle for a given set of conditions. The optimum vibration angle decreased and was better defined as the coefficient of friction increased. The results suggest the existence of an optimum dimensionless track acceleration (throw number), which does not support general industrial practice in which the track acceleration is limited when the feed cycle becomes erratic and unstable.

A New Topology of Solutions of Chemical Equations

  • Risteski, Ice B.
    • Journal of the Korean Chemical Society
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    • v.57 no.2
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    • pp.176-203
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    • 2013
  • In this work is induced a new topology of solutions of chemical equations by virtue of point-set topology in an abstract stoichiometrical space. Subgenerators of this topology are the coefficients of chemical reaction. Complex chemical reactions, as those of direct reduction of hematite with a carbon, often exhibit distinct properties which can be interpreted as higher level mathematical structures. Here we used a mathematical model that exploits the stoichiometric structure, which can be seen as a topology too, to derive an algebraic picture of chemical equations. This abstract expression suggests exploring the chemical meaning of topological concept. Topological models at different levels of realism can be used to generate a large number of reaction modifications, with a particular aim to determine their general properties. The more abstract the theory is, the stronger the cognitive power is.

A Stuty on the Dynamic Response of an Axisymmetric Buoy in Regular Waves (축대칭 부표의 규칙파중 운동특성에 대한 연구)

  • Key-Y.,Hong;Hyo-Chul,Kim;Hang-S.,Choi
    • Bulletin of the Society of Naval Architects of Korea
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    • v.23 no.3
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    • pp.1-9
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    • 1986
  • Herein the dynamic response of an axisymmetric buoy to regular wave is studied within linear potential theory. The buoy has a particular geometry so that it should experience minimum wave-exiting force on the vertical direction at a precribed wave number in water of finite depth. Invoking the Green's theorem a velocity potential is generated by distributing pulsating sources and doublets on the immersed surface of the buoy at its mean position. Hydrodynamic forces and moments are obtained approximately by summation of the products of linear pressure and directional mesh area over the immersed surface. Model tests are carried out to measure the wave-exciting forces, hydrodynamic forces and motion responses. The experimental results in general agree fairly well with the numerical ones. From the analytical and experimental works it is found that the pitching motion and its coupling effect affect significantly the motion characteristics of the freely-floating axisymmetric buoy in regular waves.

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Secondary Analysis: Focusing on Qualitative Research (이차분석 : 질적연구를 중심으로)

  • 이명선
    • Journal of Korean Academy of Nursing
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    • v.34 no.1
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    • pp.35-44
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    • 2004
  • Purpose: This article explored issues arising from secondary analysis of qualitative data and analyzed the results of qualitative secondary analysis studies published in English, focusing on the methodological aspects. Method: A total of 29 studies were identified as qualitative secondary analysis studies, retrieving from the CINAHL database from 1982 to 3rd week of April 2003. These studies were analyzed by publication year, research method, and type of approach to secondary analysis. Result: The year that the qualitative secondary analysis study first published was 1992 and the number of the studies using secondary analysis has increased after the middle of 1990s. Grounded theory was the one the most frequently used(n=11, 37.9%) and phenomenological study the second most(n=6, 20.7%). In terms of types of approach, fifteen studies(51.7%) focused on the specific concepts that were not explored in the primary studies. Nine(31.0%) focused on the specific types of participants. Six were aimed to integrate contexts or perspectives to generate more general and abstract analysis of qualitative data. Conclusion: The results of this article will stimulate methodological discussion of qualitative secondary analysis and activate qualitative studies using secondary analysis.