• 농촌계획
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• 제26권3호
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• pp.25-38
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• 2020

The purpose of this study is constructing a regional-level crop acreage choice model incorporating the impacts of producer risk aversion, and applying the constructed model to the Korean policy that promotes rice paddy conversion into non-rice crop fields. The study adopts the approach of Paris (2018) which estimates the absolute risk aversion coefficient inside of a positive mathematical programming model. A panel data set of 143 cities/counties is used for the empirical study where agricultural land in each region is allocated to 8 crops. Our estimated absolute risk aversion coefficients are smaller than those of Paris (2018), but are a little bit larger than those of the existing Korea studies based on survey or econometric methods. We found that there are close relationships among the estimated risk aversion, regional characteristics, and farming patterns. We also found that incorporating the estimated risk attitudes results in substantial differences in the impacts of the rice paddy conversion policy.

• 한국수학교육학회지시리즈A:수학교육
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• 제39권1호
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• pp.11-20
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• 2000

Compared with other subjects, mathematics has great differences in achievement. In hope of solving this problems, most schools the level-movement learning. Although they say it may have some effect because of its homogeneous group, the level groups still have differences in achievement in their students abilities. So, this study aims to present an appropriate tasks for the advanced intermediate and beginner groups and to help self-directed learning by selecting an appropriate tasks for the students' own level. To achieve thiese goals, a great deal of level tasks were developed and given to the students. After lettins them an select appropriate tasks for their own level and perform self-directed teaming, the tasks were measured carefully for their interest attitude and achievement in learning. Consequently, we tried a new method to improve uniformity and to turn teacher-centered learning into student-centered teaming. The following is the conclusion to this study. First self-directed teaming based on the selection of level tasks has meaningful effects on learning achievement in mathematics, especially for the beginner group. Second though the above method did not improve an interest for mathematics, but was very effective in the improvement of learning attitudes.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제31권3호
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• pp.291-312
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• 2017

부모 행동 지원이 학생의 학업 성취에 영향을 주는 요인은 다양하게 존재한다. 본 연구에서는 학생이 지각한 부모의 교육적 관여와 수학적 태도가 학생의 수학 학습동기와 수학불안에 미치는 영향을 분석하였다. 연구 결과 부모의 교육적 관여가 학생의 수학 학습동기에는 영향을 미치고, 수학불안에는 유의미한 영향을 미쳤으며 부모의 교육적 관여가 높은 학생일수록 수학불안이 높게 나타났다. 또한 부모의 수학적 태도는 학생의 학습동기에 유의미한 영향을 미치며, 부모의 수학적 태도가 좋을수록 학생의 수학불안은 낮아지지만 지나치게 높아지는 경우에는 학생의 수학불안을 증가시킬 수 있는 것으로 나타났다. 이는 가정배경이 교육에 맞춰진 부모의 교육적 관여가 학생의 수학 학습동기에 영향을 주지만 교육적 관여가 높아질수록 성취압력이 되어 수학불안을 야기할 수 있음을 시사한다. 또한 부모의 수학적 태도는 교육적 관여 정도와는 별개의 독립적인 것으로, 부모가 올바르고 긍정적인 인식과 태도로 양육함으로써 학생의 수학 학습동기를 높일 수 있음을 기대할 수 있다.

• 대한수학교육학회지:수학교육학연구
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• 제9권1호
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• pp.351-367
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• 1999

This study aims to study the discourses influencing high school students' concept and attitude toward mathematics, and to examine how gender differences concerning mathematical aptitude are created. This study is based on the results of previous two studies which suggested that mathematical competence differs not only according to gender, region and school year, but also even within the same gender. For this study, 12 students ranking in the top 10% at two co-ed high schools were interviewed to find out 1) what discourses are related to gender and mathematics, 2) in what way these discourses are formulated and gain currency, and 3) how they have affected students in general. Common notions concerning mathematics may be summed up as follows: 1) Most of the students believe that gender difference in mathematical aptitude results because biologically men tend to be strong in mathematics and analytical skills while women tend to have better linguistic ability. This concept can help male students' studying to have a greater learning toward mathematics. 2) A large number of the students believe that male students' studying method is based on comprehension whereas female students' method is based on retention, and hence the former group tends to be better at applying their learning than the latter group. This notion seres to encourage male students and discourage female students from tackling difficult mathematical problems. 3) Many students believe that, although female students may surpass their male counterparts in middle school or the first year of high school, they will eventually fall behind by the 3rd year. Despite research which shows that these common beliefs are not grounded in scientific proof, high-school girls, who may be strong in mathematics, lose self-confidence and feel a sense of crisis. The mechanisms which produce and reinforce such concepts as those mentioned above can be summarized as follows: 1) Regarding the choice of majors and future career paths, parents show different attitudes toward sons and daughters, and this tends to influence high-school girls and hinders them from entering mathematics-related fields. 2) Teachers with value systems based on stereo-typed gender roles affect students a great deal, and give different advice according to gender of their students, for selecting their major fields - for instance, whether to study the natural sciences as opposed to humanities. 3) This study indicates that peer-group behavior, of either support or exclusion, also reinforces the process of internalizing notions of gender difference related to mathematical aptitude. 4) The gender-based notion that men are naturally more inclined to have better mathematical ability has caused male students to choose the natural science subjects and female students to turn to the humanities. The discourses discussed above, propagated in schools and homes, and in the mass media, are continually reinforced along with general gender inequalities in the society at large.

• 한국수학교육학회지시리즈A:수학교육
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• 제58권4호
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• pp.519-530
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• 2019

선행연구에 의하면 수학 학습활동에서 인지적, 정의적 요소들 사이의 상호작용에 기반하는 메타정의는 메타인지와 유사한 방식으로 학습자의 수학적 능력과 긴밀한 역학적 관련성을 유지한다. 본 연구에서는 이러한 특성을 현상학적으로 파악하기 위하여 초등학교 5학년 수학 영재아의 소집단 문제해결 사례를 메타정의적 관점에서 분석하였다. 그 결과 수학 영재아의 인지적, 정의적 특성이 메타정의적 활동을 통해 문제해결 활동에 나타나고 있음을 알 수 있으며, 특히 문제해결자의 정의적 역량은 정서나 태도 형태의 메타정의로 문제해결 활동에 작용함을 알 수 있었다.

• 대한수학교육학회지:수학교육학연구
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• 제8권1호
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• pp.73-87
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• 1998

Recently experimental class model is growingly recommended for mathematics instruction. Freudenthal(1973) points out the difficulties of learning probability and Fischebien suggested to teach probability more intuitively through games. However detailed explanations for such classes are not easy to find. This paper is to give more detailed materials for those lessons and to check its effectiveness. We give 6 topics of probability and statistics being taught in our middle school, such as histogram, concept of probability, probability calculations, expectations, standard deviations, and correlations and each of which is given along with the experimental materials to be used. We perform a trial of the methods and found some encouragement in the students' mathematical attitudes and interests but not in the achievements. We belive that the drawback of the achievement result is due to the short length of time of our experiments.

• 대한임베디드공학회논문지
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• 제12권5호
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• pp.311-318
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• 2017

A reduced order observer is developed for depth control of a hybrid underwater glider which combines the good aspects of a conventional autonomous underwater vehicle and a underwater glider. State variables include the center of gravity of the robot and the weight of the buoyancy bag, which can not be directly measured. By using the mathematical model and available information such as directional velocities, accelerations, and attitudes, we developed a Luenberger's reduced order observer to estimate the center of gravity and the buoyancy weight. By simulations using Matlab/Simulink, the efficiency of the proposed observer is shown, where a LQR controller using full state variables is adopted as a depth controller.

• 수산해양교육연구
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• 제25권5호
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• pp.1020-1030
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• 2013

The purpose of this study was to develop the STEAM educational program based on the computer programming. STEAM education has been recently attracted to a lot of people. We had a focus of computer science in STEM fields. We used the programming language f or learning KODU. We selected appropriate topics for STEAM education and learning programming. We developed the educational program of 30 hours about selected topics and had classes for 4th and 5th grade elementary students. In order to verify the effectiveness of the educational program, we analyzed the results of pre- and posttest about GALT(Group Assessment of Logical Thinking), TTCT(Torrance Tests of Creative Thinking), science-related affective domain, and mathematical interests and attitudes tests. In the analysis results, the education program we developed had positive impacts on creativity, logical thinking, and science-related affective domain of elementary school students.

• Journal of Advanced Marine Engineering and Technology
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• 제28권4호
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• pp.675-684
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• 2004

The Helicopter system has a non-linearity and complexity. Futhermore, because of absence of its correct mathematical model. it is difficult to control accurately its attitudes for elevation angle and azimuth one. Therefore, we proposed a GA-PID control technique to control these angles efficiently. The proposed GA-PID controller can systematically generate optimal PID parameters by applying GA theory to a helicopter attitude control system. Through the computer simulation, the GA-PID technique shows better attitude control characteristic than traditional PID control technique.

• Korean Journal of Mathematics
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• 제19권4호
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• pp.453-464
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• 2011

We used SAS program in statistics class as a plan to increase effect of class. Because lease cost of SAS program is high and low-level students felt difficulty of the syntax of SAS program, I planned to introduce other instruction-software. We observe whether it's O.K. to use Excel instead of SAS program and Excel is helpful in having positive attitudes. We try to compare and analyze the merits of two programs. The purpose of this study is to apply Excel to statistics class, cut down the cost of instruction-software, and make students understand statistics more conveniently and easily.