• Journal of Korean Elementary Science Education
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• v.28 no.3
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• pp.321-330
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• 2009

This study investigated the effects of teaching-learning lesson plan using cognitive acceleration instructional strategies applied to the unit, 'The Light and Shadow' in elementary school. Two classes of the second grade elementary students (N=63) in Chungcheongbukdo districts were assigned to control and treatment groups each, and were taught about 'The Light and Shadow' for 8 class hours. For the treatment group, teaching-learning lesson plan using cognitive acceleration instructional strategies developed by this research was applied. The traditional instruction by textbook and teacher's guides was used for the control group. All students were tested with the test for concept of the shadow and the test for academic achievement about the unit. As the result of the post-test, the scores of the treatment group were higher than those of the control group. However, it was not statistically meaningful difference. The scores of the treatment group were significantly higher than those of the control group in the delayed-post-test for concept of the shadow. No significant interaction was observed with respect to the students' gender, instruction and pre-level for the concept of the shadow. Data analysis indicated that the scores of the treatment group were significantly higher than those of the control group in the post-test and delayed- post-test for the concept of the shadow in the area of object permanence. Our research work shows the effectiveness of the teaching-learning lesson using cognitive acceleration instructional strategies for the development for concept of the shadow for elementary school students, and suggests the necessity for this kind of teaching-learning program in the fields.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.357-360
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• 2008

There are many control strategies for HEV in today. Expanding motor-driving and operating at good-efficient point in engine is the key of the HEV control to increase fuel economy. There are two types of HEV supervisory control. One is rule-based control and the other is optimization control. MAX-SOC control, thermostat control, baseline status control and state-machine control are in deterministic RBC. It is simple, but powerful and easy to apply in real-time circumstance. In this study, we analysis these four control strategies in RBC (Rule-based control) and identify the each advantage and disadvantage.

• Journal of the Korean Home Economics Association
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• v.43 no.12 s.214
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• pp.113-123
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• 2005

The purpose of this study was to explore the relationships between patterns of children's requestive strategies, mother's child rearing attitude, and verbal control style. Subjects consisted of 60 5-year-old children and their mothers at preschool in Seoul. The children's requesting behavior were observed during self-selected activities in preschool. A sample of mothers of children completed the questionnaire. The result showed that the children in this study were likely to use more frequent directives of requestive strategies. Boys tended to use more indirect requestive strategies, especially demand with requestive tag. Mothers were likely to use position-oriented verbal control. Warmth and self-control of parenting and person-oriented verbal control were positively related to indirect requestive strategy of children. Rejective and controlling parenting were negatively associated with indirect requestive strategy. Position-oriented verbal control was positively related to direct requestive strategy of children.

• The Mathematical Education
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• v.48 no.3
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• pp.329-352
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• 2009

The purpose of this study was to investigate the effects of small group cooperative communicative activities on the strategies for estimating measurement. To do this, two research questions were set as follow: First, are there any differences between strategies employed by students in the experimental group and the control group before and after the estimating measurement activities? Second, are there any differences between strategies employed by students in different ability levels(upper, middle, lower) of pre-estimating measurement test in the experimental group? The research results were drawn from the investigation as below: First, the strategical change of before and after the estimating measurement tasks in the experimental group was quite noticeable. Unlike the small strategical change in the control group, small group cooperative communicative learning resulted in a decrease of simple memorization and guessing strategies and an increase of refined strategies such as the standard strategy, clustering, unit load and so on. Second, mathematical communicative activities in a small group cooperative learning showed that the students in the upper level of pre-estimating measurement test used more refined strategies and the students in the lower level used simple memorization and guessing strategy more frequently. And through interaction in small group, students could have chances to recognize error of strategies and to modify and learn strategies. In conclusion, small group cooperative activities allowed students to have chances to communicate mathematically and it is a efficient way of helping students learn estimating measurement strategies.

• English Language & Literature Teaching
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• v.15 no.4
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• pp.177-197
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• 2009

This study investigated the effects of dictation practice, in terms of listening proficiency and the use of listening strategy. The research was implemented for 15 weeks with 89 freshmen and sophomores at a Korean university. The subjects were divided into an experimental group and a control group. All conditions were the same in both groups, except that the experimental group had dictation practice on a regular basis in their listening classes through one semester. For the purpose of the study, two research questions were set; 1) Does dictation practice improve listening proficiency? 2) What are the differences in the use of listening strategies between the two groups? Does dictation practice make the participants use different listening strategies? A sample TOEIC listening test was conducted as a pre-test and post-test. A questionnaire was used to find out the differences in the use of listening strategies between the two groups. The results of this study reveal that there was no statistically difference in improvement between the two groups; however, the experimental group scored much higher on the post-test than the pre-test compared with the control group. In regard to listening strategies, among 6 listening strategies, the use of metacognitive listening strategies had a significant difference between the two groups. On the basis of the results, the study suggested some guidelines for dictation practice in EFL listening classes and called for more studies on its effects.

• Journal of Electrical Engineering and Technology
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• v.3 no.4
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• pp.538-545
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• 2008

This paper attempts to summarize torque control strategy for high performance SR drive. There are primarily two strategies for torque control. One method is direct torque control, which uses the simple control scheme and hysteresis controller to reduce the torque ripple. Another method is indirect torque control, which uses the complicated algorithms or simple distribution function to distribute each phase torque and obtain current command. The current controller is used to control phase torque by a given current command. In order to compare these two strategies of torque control, five torque control methods are introduced. The advantages and disadvantages of each method are presented. At last, they are verified by some simulations and experimental results.

• Korean Journal of Child Studies
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• v.22 no.2
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• pp.291-300
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• 2001

This study investigated the effects of shared writing strategies within a whole language approach on children's writing behaviors and abilities. The subjects were thirty-six 5-to 6-year-old kindergarten children, 18 each in the experimental and control groups. The results indicated a significant increase in frequency of spontaneous writing, quantity of writing, and quality of writing in the experimental group compared with the control group. The educational implications for kindergarten teachers are that teachers need to integrate shared writing strategies into teacher-initiated activities and use various strategies of whole language to improve literacy learning for children.

• Journal of Industrial Convergence
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• v.6 no.1
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• pp.17-33
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• 2008

The purpose of this study is to examine what sort of causes have the effect on the coping behavior of the unemployed against their job loss. For the purpose of the study, following independent variables have been selected, locus of control, self-efficacy and autotelic personality. As dependent variables, two types of coping behaviors of individual have been used, problem-focused coping strategies and symptom-focused coping strategies. To test the hypotheses, structural equation modeling was employed. The model showed adequate fit to the data. The results of structural equation modeling exhibit that internal locus of control, self-efficacy and autotelic personality were positively related problem-focused coping strategies. And self-efficacy was negatively related to symptom-focused coping strategies. Implications are discussed and future research directions are outlined.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.04b
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• pp.39-55
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• 2002

• Earthquakes and Structures
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• v.6 no.2
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• pp.217-235
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• 2014

In this paper, different feedback control strategies are presented for active seismic control using proportional-integral-derivative (PID) type controllers. The parameters of PID controller are found by using an numerical algorithm considering time delay, maximum allowed control force and time domain analyses of shear buildings under different earthquake excitations. The numerical algorithm scans combinations of different controller parameters such as proportional gain ($K_p$), integral time ($T_i$) and derivative time ($T_d$) in order to minimize a defined response of the structure. The controllers for displacement, velocity and acceleration feedback control strategies are tuned for structures with active control at the first story and all stories. The performance and robustness of different feedback controls on time and frequency responses of structures are evaluated. All feedback controls are generally robust for the changing properties of the structure, but acceleration feedback control is the best one for efficiency and stability of control system.