• Journal of Industrial Technology
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• v.21 no.A
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• pp.41-50
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• 2001

A comparison is made of the temperature distribution and heat loss from a trapezoidal profile fin using two different 3-dimensional methods. These two methods are analytical and finite difference methods. In the finite difference method 78 nodes are used for a fourth of the fin. A trapezoidal profile fin being the height of the fin tip is half of that of the fin base is chosen arbitrarily as the model. One of the results shows that the relative error in the total convection heat loss obtained by using 78 nodes in the finite difference method as compared to the heat conduction through the fin root obtained by analytic method seems to be good (i.e., -3.5%

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.230-231
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• 2011

There is a merit a planetary gear set disperses a delivery load, and to decrease loss of friction and noise. But, in addition to meshing this internal and external gear simultaneously and phase difference by the tooth contact point and the time difference occurs asymmetric and symmetric sideband noise and vibration caused by the modulation in the vehicle. Existing planetary gear set research have progressed to reduce the cause of the sideband as run-out, pitch error and imbalance. In this paper presents a method for the design of the carrier phase difference by developing various theorys and experiments for gear noise.

• Journal of applied mathematics & informatics
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• v.23 no.1_2
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• pp.353-359
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• 2007

A necessary and sufficient condition for Demyanov difference and Minkowski difference of compact convex subsets in $R^2$ being equal is given in this paper. Several examples are computed by Matlab to test our result. The necessary and sufficient condition makes us to compute Clarke subdifferential by quasidifferential for a special of Lipschitz functions.

• Journal of Korean Academy of Nursing
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• v.6 no.1
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• pp.29-40
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• 1976

This study attempted to measure personality changes in collegiate nursing students as a result of their psychiatric nursing practice. The study population consisted of 310 students in 8 colleges of nursing in Korea, 96 with psychiatric practice, 103 with other clinical practice and III without clinical practice experience. The objectives of the study were to identify: 1. The self-actualization scores of nursing students resulting from psychiatric nursing practice. 2. The self-actualization scores of nursing students resulting from other clinical nursing practice. 3. The difference between scores for students with clinical practice experience and those without experience. 4. The relevance between self-actualization and sibling order. 5. The relevance between self- actualization and religion. 6. The coefficiently scores for students before and after clinical practice. The instrument used was the Personal Orientation Inventory (POI), developed by Shostrom. It provides a measure of values and behavior which are thought to be of importance in the development of self- actualization. The main findings of the study were as follows: 1. There was a significant difference in the Time Competence, Self Regard, and Nature of Man scales resulting from psychiatric nursing practice. 2. There was a significant difference in the Inner Directed, Existentialist, Feeling Reactivity, Spontaneity, Nature of Man and Capacity for Intimate Contact scales resulting from other clinical nursing practice. 3. There was a significant difference in the Inner Directed, Feeling Reactivity, Spontaneity, Self- Regard and Capacity for Intimate Contact scales between students with clinical practice and those without practice. 4. There was a significant difference in the Self-Acceptance scale for both the eldest and the youngest siblings. 5. There was a significant difference in the Time Competence, Inner Directed, Existentialist, Self-Acceptance and Capacity for Intimate Contact scales for middle and youngest siblings, 6. There was a significant difference in the Existentialist scale between students with a religion and those without one. 7. There was a significant difference for students without a religion in the Time Competence, Inner Directed, Self-Regard, Nature of Man, and Capacity for Intimate Contact scales after clinical practice. 8. There was a significant difference for students, with a religion in the Inner Directed, Existentialist, Spontaneity, and Nature of Man scales after clinical practice. 9. There was a significant difference for students in the Self- Actualizing value, Spontaneity, Nature of Man and Synergy scales according to whether their parents had a religion or not. 10. Before and after practice, significantly different correlations were found between the Time Competence and Capacity for Intimate Contact scales : the Inner Directed and Existentialist scales ; the Self- Actualizing Value and the Feeling Reactivity, Spontaneity, Self-Regard and Nature of Man scales : the Feeling Reactivity and Acceptance of Aggression scales: the Spontaneity and the Self-Regard and Nature of Man scales; and between the Self-Regard and Nature of Man scales.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.307-314
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• 2005

In this paper we consider positive solutions of the following difference equation $$x_{n+l}\;=\;min[{\frac{A}{x_{n}},{\frac{B}{x_{n-2}}}],\;A,B\;>\;0$$. We prove that every positive solution is eventually periodic. Also, we present here some results concerning positive solutions of the difference equation $$x_{n+l}\;=\;min[{\frac{A}{x_{n}x_{n-1}{\cdots}x_{n-k}},{\frac{B}{x_{n-(k+2)}{\cdots}x_{n-(2k+2)}}],\;A,B\;>\;0$$.

• Communications of the Korean Mathematical Society
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• v.31 no.1
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• pp.41-52
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• 2016

In the present paper, by generalizing the definition of the zero-difference balanced (ZDB) function to be the G-ZDB function, several classes of G-ZDB functions are constructed based on properties of cyclotomic numbers. Furthermore, some special constant composition codes are obtained directly from G-ZDB functions.

• Journal of applied mathematics & informatics
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• v.8 no.1
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• pp.111-128
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• 2001

In this paper, we consider the oscillation of the second-order neutral difference equation Δ²(x/sub n/ - px/sub n-r/) + q/sub n/f(x/sub n/ - σ/sub n/) = 0 as well as the oscillatory behavior of the corresponding ordinary difference equation Δ²z/sub n/ + q/sub n/f(R(n,λ)z/sub n/) = 0

• Journal of the Korean Mathematical Society
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• v.36 no.2
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• pp.299-316
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• 1999

We consider two finite difference approxiamations to a singular boundary value problem arising in the study of a nonlinear circular membrane under normal pressure. It is shown that the rates of convergence are O(h) and O($h^2$), respectively. An iterative scheme is introduced which converges to the solution of the finite difference equations. Finally the numerical experiments are given

• The Pure and Applied Mathematics
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• v.17 no.2
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• pp.189-197
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• 2010

We give an upper bound for the estimation of the difference between both sides of the well-known H$\ddot{o}$lder's inequality. Moreover, an upper bound for the estimation of the difference of the integral form of H$\ddot{o}$lder's inequality is also obtained. The results of this paper are natural generalizations and refinements of those of [2-4].

• Journal of Advanced Marine Engineering and Technology
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• v.18 no.3
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• pp.94-101
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• 1994

To develope the new simulator for the analysis of fluid flow information, the influence of various convective difference schemes were evaluated. General curvilinear coordinate system with nonorthogonal grids was adopted for the successful analysis of various complex geometries. Computation results show that if we can not obtain full grid numbers within available computational environment, we need to use higher order finite difference schemes to keep the prediction accuracy.