• Journal of applied mathematics & informatics
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• 제34권1_2호
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• pp.145-156
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• 2016

It is known that certain convolution sums can be expressed as a combination of divisor functions and Bernoulli formula. In this article, we consider relationship between fifth-order combinatoric convolution sums of divisor functions and Bernoulli polynomials. As applications of these identities, we give a concrete interpretation in terms of the procedural modeling method.

• Journal of Biosystems Engineering
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• 제21권4호
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• pp.399-405
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• 1996

In order to maintain a constant speed ratio between the tractor and attached seed planter, a feedback control unit to rotate the feed shaft of the planter in proportional to the ground speed of the tractor was designed. The fifth wheel was used as a ground speed sensor for the unit. Using this control unit a feed shaft driving system was developed and tested to estimate its performance both in laboratory and fields. The test results showed that the system rotates the feed shaft proportionally to the ground speed in the range of the normal planting speed of 0.5-0.8m/s with errors less than 5%.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.469-477
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• 1996

In order to maintain a constant ratio between the ground wheel and fed shaft of planters, a feedback control unit was designed to drive the feed shaft in proportional to the ground speed. The fifth wheel was used as a ground speed sensor for the control unit. Using this control unit a feed shaft driving system was developed and tested both in the laboratory and field to evaluate it performance . The test results showed that the system drove the feed shaft in proportional to the ground speed in the normal planting speed range of 0.5 -0.8m/s with an error of less than 5%.

• 한국수학교육학회:학술대회논문집
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• 한국수학교육학회 2006년도 제36회 전국수학교육연구대회 프로시딩
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• pp.1-16
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• 2006

The purpose of this study is to investigate how fifth and sixth graders recognize average and to find out suggestions for teaching/learning methods of average by examining which difference there is depending on the way of the word problem presentation. To solve these study questions, With the way of the word problem presentation set up as experimental treatment experiment was conducted to analyze these. In conclusion, since students who did not learn the regular course of average values had various informal concepts already, it is needed to consider handling more various concepts of average in order to enable students to expand flexible thoughts. And informal concepts of average students showed were the same or similar to types of formalized concepts and had logicality and propriety in their own way. Compared with fifth graders, sixth graders showed a wide difference in informal concepts of average depending on the way of the word problem presentation.

• 대한수학회보
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• 제61권2호
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• pp.317-333
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• 2024

For the classes of analytic functions f defined on the unit disk satisfying ${\frac{2zf'(z)}{f(z)-f(-z)}}{\prec}{\varphi}(z)$) and ${\frac{(2zf'(z))'}{(f(z)-f(-z))'}}{\prec}{\varphi}(z)$, denoted by S^*_s(𝜑) and C_s(𝜑), respectively, the sharp bound of the n^th Taylor coefficients are known for n = 2, 3 and 4. In this paper, we obtain the sharp bound of the fifth coefficient. Additionally, the sharp lower and upper estimates of the third order Hermitian Toeplitz determinant for the functions belonging to these classes are determined. The applications of our results lead to the establishment of certain new and previously known results.

• 대한수학교육학회지:학교수학
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• 제2권1호
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• pp.203-241
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• 2000

This study aims to suggest a model of task development for mathematics performance assessment and to develop performance tasks for the fifth graders in the primary school on the basis of this model. In order to achieve these aims, the following inquiry questions were set up: (1) to develop open-ended tasks and projects for the fifth graders, (2) to develop checklists for measuring the abilities of mathematical reasoning, problem solving, connection, communication of the fifth graders more deeply when performance assessment tasks are implemented and (3) to examine the appropriateness of performance tasks and checklists and to modify them when is needed through applying these tasks to pupils. The consequences of applying some tasks and analysing some work samples of pupils are as follows. Firstly, pupils need more diverse thinking ability. Secondly, pupils want in the ability of analysing the meaning of mathematical concepts in relation to real world. Thirdly, pupils can calculate precisely but they want in the ability of explaining their ideas and strategies. Fourthly, pupils can find patterns in sequences of numbers or figures but they have difficulty in generalizing these patterns, predicting and demonstrating. Fifthly, pupils are familiar with procedural knowledge more than conceptual knowledge. From these analyses, it is concluded that performance tasks and checklists developed in this study are improved assessment tools for measuring mathematical abilities of pupils, and that we should improve mathematics instruction for pupils to understand mathematical concepts deeply, solve problems, reason mathematically, connect mathematics to real world and other disciplines, and communicate about mathematics.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1081-1090
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• 2003

Two different electronically resonant two-dimensional spectroscopies are described. The first, two-color photon echo peak shift spectroscopy, is sensitive to correlations in transition frequency between the initial and probed (final) states. It provides new insight into the mechanism of ultrafast solvation and should prove useful for characterizing dynamics in inhomogeneous systems in general. The second technique, fifth order threepulse scattering, contains two coherence periods whose durations are controlled. The entire two-dimensional surface was recorded for a dye molecule in dilute solution and a photosynthetic light-harvesting complex. The data provide insight into the short-time dynamics of solvation and exciton relaxation, respectively.

• Journal of applied mathematics & informatics
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• 제42권1호
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• pp.139-148
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• 2024

The purpose of this research is to investigate sufficient conditions for the existence of limit cycles of the fifth-order differential equation x⁽⁵⁾ + (p² + q²)$_{x}^{...}$ + p²q²$_{x}^{.}$ = εF(t, x, $_{x}^{.}$, $_{x}^{..}$, $_{x}^{...}$, $_{x}^{....}$), where p, q are rational numbers different from 0, p ≠ ±q, ε is a small real parameter, and F is a 2kπ-periodic function in the variable t. Also, we provide some applications.

• 한국광학회:학술대회논문집
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• 한국광학회 1996년도 Advance Program of 13th optics andquantum Electronics conference, 1996제13 회 광학 및 양자전자 학술 발표회 논문 요약집
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• pp.18-18
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• 1996

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.135-141
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• 2005

A hybrid central-WENO scheme is proposed. The fifth order WENO-LF scheme is coupled with a central flux scheme at cell face. Two sub-schemes, the WENO-LF scheme and the central flux scheme, are switched by a weighting function. The efficiency and accuracy of the proposed hybrid central-WENO scheme is validated through several numerical experiments.