• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.969-980
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• 2018

This paper aims to design of the neutrosophic fuzzy-PID controller and it has been compared with the conventional fuzzy-PID controller for position tracking control in terms of robustness. In the neutrosophic fuzzy-PID controller, error (e) and change of error (ce) were assessed separately on two fuzzy inference systems (FISs). In this study, the designed method is different from the conventional fuzzy logic controller design, membership degrees of antecedent variables were determined by using the T(true), I(indeterminacy), and F(false) membership functions. These membership functions are grouped on the universe of discourse with the neutrosophic set approach. These methods were tested on three-dimensional (3-D) position-tracking control application of a spherical robot manipulator in the MATLAB Simulink. In all tests, reference trajectory was defined for movements of all axes of the robot manipulator. According to the results of the study, when the moment of inertia of the rotor is changed, less overshoot ratio and less oscillation are obtained in the neutrosophic fuzzy-PID controller. Thus, our suggested method is seen to be more robust than the fuzzy-PID controllers.

• 한국지형공간정보학회:학술대회논문집
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• 2002.11a
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• pp.133-140
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• 2002

This paper presents a method for line segment grouping used for detection of various building roofs. First, by using edge preserving filtering. noise is eliminated and then images are segmented by watershed algorithm, which preserves location of edge pixels. To extract line segments between control points from boundary of each region, we calculate curvature of each pixel on the boundary and then find the control points. Line linking is performed according to direction and length of line segments and finally the location of line segments is adjusted using gradient magnitudes of all pixels of the line segment. The algorithm has been applied to aerial imagery and the results show accurate building roof detection.

• Journal of the Korean earth science society
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• v.21 no.2
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• pp.103-115
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• 2000

The ability-grouping is the essence of the seventh educational curriculum, applied to school from year 2000, and its enriched-supplementary type will be carried out for science course. This study examines the effect of the enriched-supplementary ability-grouping within class to student's academic achievement and the attitude, related to science. Thus we developed teaching and learning methods with intellectual level about the subject of 'Water Circulation and Weather Change' in Middle-School Science 2. Then we tested 152 eighth graders who were divided into the experimental and control groups. The experimental one was taught through the ability-grouping for about six weeks, while the control through conventional lecture. The improvement of the experimental group in academic achievement was more effective than that of the control, and particularly to below-average students who ranked in lower thirty percent. The experimental one got more negative change in domain 'Science as a Subject, and in subdomain 'Anxiety in Science Lesson'. While outstanding students who ranked in upper thirty percent showed a significant positive change in subdomain 'Satisfaction in Teaching Method, the below-average were negatively changed in subdomain 'Anxiety in Science Lesson'. The current ability-grouping was suitable for the improvement of academic achievement, but not for the general attitude related to science. In order to enhance the ability-grouping effect in science education, we need to additionally consider student's interest and concern in grouping, and develop various teaching and learning methods together with proper textbook contents.

• Journal of The Korean Association For Science Education
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• v.18 no.1
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• pp.61-70
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• 1998

This study investigated the effects of grouping (group composition) in cooperative learning strategy upon students' achievement, the attitude toward science instruction, the perception of learning environment, and the self-esteem. Three different groups were used in this study. For the two treatment groups with cooperative learning strategies, High-Medium-Low ability grouping (HML) and High-Low I Medium-Medium ability grouping (HL/MM) were used. For the control group, traditional instruction was used. Before the instructions, the short-version Group Assessment of Logical Thinking, the test of attitudes toward science instruction, the perception questionnaire of learning environment, and the questionnaire of self-esteem were administered, and their scores were used as covariates. Mid-term examination score was used as a blocking variable. After the instructions, a researcher-made achievement test consisting of three subtests (knowledge, understanding, and application), the test of attitude toward science instruction, the perception questionnaire of learning environment, and the questionnaire of self-esteem were administered. The ANCOVA results revealed that there were significant interactions between the instruction and the level of prior achievement although there were no significant differences in all subtest scores of the achievement test. The high-level students in the HL/MM cooperative group performed better than those in the control group and the HML cooperative group. The low-level students in the HL/MM cooperative group also performed better in the subtest of knowledge than those in the other groups. However, the medium-level students in the HML cooperative group scored better than those in the control group and the HL/MM cooperative group. Significant main effect was also found in the perception of learning environment but not in the attitude toward science instruction and self-esteem. The cooperative groups, regardless of grouping, exhibited more positive perception than the control group.

• Journal of the Korean Chemical Society
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• v.51 no.3
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• pp.270-278
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• 2007

In this study, we investigated the effects of grouping with respect to the level of students' agreeableness on 6th graders' science achievement, self-efficacy, and science learning motivation in cooperative learning. Three classes (72 students) from an elementary school were randomly assigned to a control group and treatment groups. An agreeableness test, self-efficacy test, and science learning motivation test were administered as pretests. The students of the treatment groups were grouped either homogeneously or heterogeneously on the basis of their agreeableness levels and were taught with a cooperative learning strategy, whereas the students of the control group were randomly grouped and were taught with a traditional method. The cooperative learning intervention lasted for 5 weeks (16 class periods). After the instructions, tests regarding achievement, self-efficacy, and science learning motivation were administered as posttests. The results indicated that the students of the homogeneous and/or the heterogeneous groups significantly outperformed those of the control group in the achievement test. However, students' achievement was not influenced by the grouping method on the basis of students' agreeableness. No significantly differences among the groups were found in the self-efficacy and science learning motivation.

• Journal of Science Education
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• v.41 no.2
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• pp.195-212
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• 2017

Small group learning is an educational approach to allow students to solve the problems and to achieve a common goal. Especially, small group learning in science education is one of the most important educational approaches and effective to ensure understanding of a topic. Small group learning consisting of three students in science education maximize student understanding and learning efficiency. However, It is reported that the effects of small group learning on achievement show different results, corresponding to different grouping methods(homogeneous/heterogeneous). This study investigated the effects of grouping method on difference of ecological niche of photosynthesis concepts. To achieve this, 1107 7th students were composed of homogeneous and heterogeneous groups classified into top, middle, and bottom levels. The photosynthesis units were divided into four categories: the photosynthesizing place, the substances of photosynthesis, required materials for the photosynthesizing, and environmental factors affecting photosynthesis. A questionnaire was composed by selecting concepts having a frequency of 4% or more based on prior studies on the change of the ecological status of photosynthesis. The questionnaire was scored in terms of relativity and understanding on each of the proposed concepts in the four categories. The result of this study is as set forth below. 1) There was an enhancement of learning the concept of science in small group classes consisting of 3 students. 2) To enhance the average upon composing of a group, it is proposed that the group should be formed homogeneously, and to reduce the deviation between the members, it is proposed that the group should be formed heterogeneously. Through this study, it is expected that specific studies verifying the difference or effect on the duplicity of results are conducted based on the composition of groups.

• Fibers and Polymers
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• v.1 no.1
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• pp.55-58
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• 2000

We present a new approach to bale laydown grouping, which improves the laydown to laydown uniformities, compared to conventional approaches. In this approach, we use a frequency-relative picking method based on an HVI quality index for cotton bale selection and laydown formation. We demonstrate the effectiveness of this approach by computer simulation on real HVI data of 1500 cotton bales. Simulation results show that the proposed method significantly outperforms random picking.

• Spatial Information Research
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• v.20 no.2
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• pp.137-153
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• 2012

Until now, many indexing methods that can reduce update cost have been proposed for managing massive moving objects. Because indexing methods for moving objects have to be updated periodically for managing moving objects that change their location data frequently. However these kinds indexing methods occur big load that exceed system capacity when the number of moving objects increase dramatically. In this paper, we propose the update frequency reducing method to combine MapReduce and existing indices. We use the update request grouping method for each moving object by using MapReduce. We decide to update by comparing the latest data and the oldest data in grouping data. We reduce update frequency by updating the latest data only. When update is delayed, for the data should not be lost and updated periodically, we store the data in a certain period of time in the hash table that keep previous update data. By the performance evaluation, we can prove that the proposed method reduces the update frequency by comparison with methods that are not applied the proposed method.

• The Korean Journal of Applied Statistics
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• v.18 no.1
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• pp.1-13
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• 2005

Latent Class model has been considered recently by many researchers and practitioners as a tool for identifying heterogeneous segments or groups in a population, and grouping objects into the segments. In this paper we consider data on prostate cancer patients from Korean National Cancer Institute and propose a method for grouping prostate cancer patients by using latent class Poisson model. A Bayesian approach equipped with a Markov chain Monte Carlo method is used to overcome the limit of classical likelihood approaches. Advantages of the proposed Bayesian method are easy estimation of parameters with their standard errors, segmentation of objects into groups, and provision of uncertainty measures for the segmentation. In addition, we provide a method to determine an appropriate number of segments for the given data so that the method automatically chooses the number of segments and partitions objects into heterogeneous segments.

• Journal of The Korean Association For Science Education
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• v.22 no.4
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• pp.717-724
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• 2002

In this study. the effects of grouping by students' agreeableness in cooperative learning strategy applied to middle school science classes on their achievement. confidence, satisfaction, attitude toward science class, and cohesion of group members were investigated. One hundred and fifty-eight students were assigned to control group, homogeneous group and heterogeneous group, and taught about separation of mixture for 7 class hours. The results revealed that there was no significant difference in the achievement test scores. However, significant interaction between the instruction and the level of agreeableness were found in the satisfaction and the cohesion of group members. Students of higher agreeableness level in the homogeneous group were more satisfied with science class and cohesive. Students' attitude toward science class in the homogeneous group was also significantly higher than those in the other groups.