• Research in Mathematical Education
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• v.9 no.4 s.24
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• pp.335-340
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• 2005

According to the mathematics educational practice and research about gifted children in some secondary schools in China, the paper presented some relevant problems: 1. Missing or mistaken selecting in gifted children in China. It included the limitations of identifying standard and the fault of understanding and doing in practice, administration disturbance and emotional inclination. 2. Backward traditional mathematics teaching in gifted children in China. It included lower teaching starting point, slower teaching planned speed, simpler teaching contents and so on. The paper analyzed the problems, and made enlightenment for gifted children's mathematical teaching strategies: raising starting point of contents; emphasizing essential principles and skills; using flexible teaching methods; encouraging discover and creativity and developing harmoniously psychological level and mathematical ability. As to these strategies, some detail measures were offered as well.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.676-685
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• 1993

A mathematical model was developed to quantify the separation process of threshed grain-straw mixtures. It was made to predict the separation loss from a separation unit consisted of stationary crimped sieve with rotating inner rotor. Experiments were performed to prove the mathematical model by changing various levels of pertinent variables for rice. Good Agreement between the simulated results and observed data under the various test conditions, such as inclination angle of the separator, vane pitch, rotor speed, MOG/G ratio, feed rate, and crop variety and moisture content, were confirmed.

• The Mathematical Education
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• v.38 no.2
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• pp.129-144
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• 1999

The purpose of our work is to developing the program of math. camp to improve underachiever's mathematical disposition. To do this, the following research were taken; (1)Analysis of current status of programs for underachievers (2)Analysis of inclination to mathematics(We collected the data from 2 classes of middle schools) (3)Prepare and apply the program of math. camp for the students including underachievers, and then analysis the effect of the math. camp The results of this study is as follows; (1)Only 40% of investigated schools have their own programs for underachievers. But almost all general high schools do not have such programs because students do not want. More than half of the investigated teachers suggested that the most important thing for underachievers is the induction of motivation for mathematics. (2)Many students dislike mathematics from 5∼6 grade of elementary school, and more than 50% of students think that 'measure' and 'equations' items are difficult. (3) After attending the math. camp based on the games and activities in small groups, the students in the middle-ranking group showed more positive reactions against the items of mathematical disposition and attitude tests. The students in the row-ranking group were improved in the 'self-confidence' and 'will' items of mathematical disposition test and in the 'superiority' and 'interest' items of mathematical attitude test.

• The Mathematical Education
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• v.54 no.3
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• pp.223-240
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• 2015

This study qualitatively investigates the nature of the challenges that a student who is highly successful in mathematics faces in learning college-level elementary statistics. The study draws on the constructs of eagerness, flexibility and willingness to characterize the necessary disposition for critical thinking that is essential in learning statistics. The case study is based on data collected through a survey assessment and a follow-up interview with a mathematics major enrolled in an elementary college statistics course at the time of the study. The qualitative analysis relies on the student's verbal descriptions of the challenges he was experiencing in the course. The findings suggest that while his strong inclination towards inquisitive learning and strong understanding of mathematical concepts supported this student's mathematics learning, the same characteristics might have been causing him difficulties in learning college-level elementary statistics.

• Journal of Elementary Mathematics Education in Korea
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• v.10 no.2
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• pp.195-219
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• 2006

This study was proposed to analyze mathematical communication activity and mathematical attitudes while students were solving project problem and to consider how the conclusions effects mathematics education. This study analyzed through qualitative research method. The questions for this study are following, First, how does the process of the mathematical communication activity proceed during solving project problem in a small group? Second, what reactions can be shown on mathematical attitudes during solving project problem in a small group? Four project problems sampled from pilot study in order to examine these questions were applied on two small groups consisting of four 5th grade students. It was recorded while each group was finding out the solution of the given problems. Afterward, consequences were analyzed according to each question after all contents were noted. Consequently, conclusions can be derived as follows. First, it was shown that each student used different elements of contents in mathematical communication activity. Second, during mathematical communication activity, most students preferred common languages to mathematical ones. Third, it was found that each student has their own mathematical attitude. Fourth, Students were more interested in the game project problem and the practical using project problem than others.

• Communications of Mathematical Education
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• v.25 no.1
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• pp.167-184
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• 2011

In D university, 2010 year engineering freshmen were taken basic mathematical ability test and were given basic mathematical ability improvement program based on the test. In order to study the effect of this program for scholastic achievement, we analyse basic mathematical ability test score and college mathematics score among student groups. And to study the effect of this program for scholastic motivation, we survey the mathematical inclination, the recognition of mathematics, and classes of mathematics. As results, engineering freshmen in D university were poor at basic mathematical ability and basic mathematical ability improvement program effected scholastic achievement and motivation in mathematics, greatly. For the success of college mathematics in engineering college, this study suggests basic mathematical ability test and the survey for engineering freshmen's mathematical background. Finally, we suggest that college mathematics must be focused on the improvement of basic mathematical abilities.

• Journal of Biosystems Engineering
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• v.42 no.3
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• pp.127-135
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• 2017

Purpose: Purpose: The usability of a mathematical model modified for analysis of the static stability of an asymmetric tractor-harvester system was investigated. Method: The modified asynchronous mathematical model was validated through empirical experiments, and the effects of movements of the center of gravity (CG) coordinates on the stability against lateral overturning were analyzed through simulations. Results: Changes in the lateral overturning angle of the system were investigated when the coordinates of the CG of the system were moved within the variable range. The errors between simulation results and empirical experiments were compared, and the results were -4.7% at the left side overturning and -0.1% at the right side overturning. The asymmetric system was characterized in such a way that the right side overturning had an increase in overturning angle in the (+) variable range, while it had a decrease in overturning angle in the (-) variable range. In addition, the left side overturning showed an opposite result to that of the right side. At the declination angle (296<${\gamma}$<76), the right side overturning had an increase in the maximum overturning angle of 3.6%, in the minimum overturning angle of 20.3%, and in the mean overturning angle of 15.9%. Furthermore, at the declination angle (284<${\gamma}$<64), the left side overturning had a decrease in the maximum overturning angle of 29.2%, in the minimum overturning angle of 44%, and in a mean overturning angle of 39.7%. Conclusion: The modified mathematical model was useful for predicting the overturning angle of the asymmetric tractor-harvester system, and verified that a movement of the CG coordinates had a critical effect on its stability. In particular, the left side overturning was the most vulnerable to stability, regardless of the direction of declination angle.

• Journal of Biosystems Engineering
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• v.16 no.1
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• pp.27-36
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• 1991

This study was carried out getting basic data for developing a new combine which is suitable for the cultivating situation in Korea or Southeast Asia. The relation of the amount of unthreshed grains and the axial displacement of crop in threshing process was attempted to formulate mathematically in a threshing chamber of axial-flow threshing unit. It was found that unthreshed grain is an exponetially-decaying functon of axial displacement of grains based on available data. Threshing experiments were performed to validate the mathematical model by changing various levels of pertinent variables for malting barley. Good correlation were obtained between the theoretical calculation and observed data for various test conditions, such as inclination, vane pitch, concave length, drum speed, feeding velocity, stream weight, moisture content. Therefore the model can be used for general purpose to find the amount of unthreshed grain if the mean rate of occurence of threshing of kernels(${\lambda}_{\tau}$) is properly calibrated considering some other operating conditions and crop conditions which are not involved in this analysis.

• Korean Journal of Geomatics
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• v.1 no.1
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• pp.69-74
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• 2001

In conventional photogrammetry, three-dimensional coordinates are obtained from two consecutive images of a stationary object photographed from two exposure stations, separated by a certain distance. However, it is impossible to photograph moving objects from two stations with one camera at the same time. Various methods to overcome this obstacle were devised e. g. taking the left and right scenes simultaneously with one camera using a beam splitter attached to the front, thus creating a stereo scene in one image. A beam splitter consists of two outer mirrors and two inner mirrors. This paper deals with research where the optical principles of the beam splitter were evaluated based on light path phenomena between the outer mirrors and the inner mirrors. A mathematical model of the geometric configuration was derived for the beam splitter. This allows us to design and control a beam splitter to obtain maximum scale and maximum base-height ratio by stepwise application of the mathematical model. The results show that the beam splitter is a very useful tool for stereophotography with one camera. The optimum geometric configurations ensuring maximum scale and base-height ratio are closely related to inner and outer reflector sizes, their inclination angles and the offsets between the outer mirrors.

• Coupled systems mechanics
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• v.9 no.4
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• pp.343-358
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• 2020

The present research deals with the time-harmonic deformation in transversely isotropic magneto thermoelastic solid with two temperature (2T), rotation due to inclined load and laser pulse. Generalized theory of thermoelasticity has been formulated for this mathematical model. The entire thermo-elastic medium is rotating with uniform angular velocity and subjected to thermally insulated and isothermal boundaries. The inclined load is supposed to be a linear combination of a normal load and a tangential load. The Fourier transform techniques have been used to find the solution to the problem. The displacement components, stress components, and conductive temperature distribution with the horizontal distance are computed in the transformed domain and further calculated in the physical domain using numerical inversion techniques. The effect of angle of inclination of normal and tangential load for Green Lindsay Model and time-harmonic source for Lord Shulman model is depicted graphically on the resulting quantities.