• Journal of the Korea Society of Computer and Information
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• v.20 no.9
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• pp.31-37
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• 2015

Symmetry is easily found in animals and plants as well as in artificial structures. It is useful not only for human cognitive process but also for image understanding by computer. Application areas include face detection and recognition, indexing of image database, image segmentation and detection, and analysis of medical images. The method used in this paper extracts edges, and the perpendicular bisector of any pair of selected edge points is considered to be a candidate axis of symmetry. The coefficients of the perpendicular bisectors are accumulated in the coefficient space. Axis of symmetry is determined to be the line for which the histogram has maximum value. This method shows good results, but the usefulness of the method is restricted because the amount of computation increases proportional to the square of the number of edges. In this paper, an acceleration method is proposed which performs $2^{2n}$ times faster than the original one. Experiment on 20 test images shows that the proposed method using level-3 image segmentation performs 63.9 times faster than the original method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1324-1343
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• 2014

In recent years, the problem of spectrum mobility in Cognitive Radio (CR) Networks has been widely investigated. In order to utilize spectrum resources completely, many spectrum handoff techniques based on game theory have been proposed, but most studies only concern that users how to achieve better payoffs, without much attention to the diverse needs of users. In this paper, we propose a new channel-switching model based on game theory, using a prioritized approach to meet the diverse needs of users in two different modes (CQ and PS). At the same time, this paper proposes some acceleration techniques to reach the Nash equilibrium more efficiently. We evaluate the performance of the proposed schemes depending on priority using real channel availability measurements, and conclude that the channel quality function (CQ) mode provide better service for priority user but the plan-sorting (PS) mode can be more suitable in multiple priority users exist scene.

• Journal of The Korean Association For Science Education
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• v.22 no.1
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• pp.110-121
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• 2002

In this study, the verbal interactions occurred during the CASE(Cognitive Acceleration through Science Education) activities in the middle school science class has been analyzed regarding with students cognitive level. The subjects were 24 students of 6 groups in a middle school in Korea. Verbal interactions within group discussions during CASE activities were audio-taped, transcribed, and analyzed. Also, classroom observation and interview with students were carried out. The results showed that the student with higher cognitive level tended to be a group leader. They had strong influences on the group discussions in each step of problem solving. Also, the higher cognitive level students were more active in metacognitive discussion and more often used scientific terms. When their group met difficulties in each stage of problem solving, such as perception of problem and designing experiment, the higher cognitive level students suggested some ideas to help their peers and gave them an explanation of how they worked. Low cognitive level students had difficulties in perception and solving the problem as compared with high cognitive students. It was common during activities for the low cognitive level students to fail to identify variables and to distinguish between dependent variables and independent variables. They failed to hold a number of variables at once. However, the metacognitive questions from their peers or teacher were helpful for them to construct the concept of controlling variables. If there is no student who has a high level of thinking in a group, it was necessary to intervene for teacher. A well judged questions from teacher created the cognitive conflict which causes the students to reconstruct their strategy for problem solving and reinforce the control of variables reasoning pattern. From the above results, it is concluded that students' cognitive levels are much related to the verbal interaction patterns. This suggests that teacher should consider individual student's cognitive level in organizing groups and intervene to facilitate the environment for metacognitive interaction.

• Journal of The Korean Association For Science Education
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• v.25 no.7
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• pp.787-793
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• 2005

The purposes of this study were to investigate the development of probabilistic thinking in relation to the cognitive level of elementary school students and to analyze the effects of probability activities in Thinking Science(TS) program on the development of probabilistic thinking. 152 6th grade elementary school students compiled the sample group which was divided into an experimental group and a control group. Probability activities in TS program were used with the experimental group, while the normal curriculum was conducted with the control group. Both the experimental and control group were assessed with Science Reasoning Task II and a probabilistic thinking test before execution of this investigation and were post-tested with probabilistic thinking test after the project period was complete. Results of this study showed that the students in the concrete operational stage and transitional stage used subjective strategy together with quantitative strategy in probability problem-solving, and students in the early formal operational stage used quantitative strategy in probability problem-solving. It was also found that the higher the cognitive level of students, the higher the probabilistic thinking level. The probability activities of the TS program influenced the development of probabilistic thinking of elementary school students. Assessing the development of probabilistic thinking on the basis of the cognitive level found that the level of effectiveness was significantly higher for students in the early concrete operational stage and transitional stage than students in any other stage.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.139-148
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• 2020

Walking is one of the most natural and repetitive actions we do in our daily lives. However, many modern people have problems with shoulders, back and spine due to incorrect walking habits. Therefore, it is becoming important to diagnose and correct wrong walking habits, for example, in-toeing, out-toeing, etc. early, which can be a precursor to various diseases. In this study, we developed the system to diagnose and prevent incorrect gait by grasping and analyzing the angle and muscle activity of the foot according to the typical wrong gait type through MPU 6050 acceleration sensor and the surface EMG sensor. Through a smartphone, numerical and visualization screens based on walking can be used to represent the angle of the feet, real-time EMG values, and even the number of steps. The correction effect was enhanced by improving the cognitive ability through a system that allows individuals to easily diagnose gait through smart devices and improve them according to their own problems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.483-489
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• 2018

Driving behaviors are reported to be vulnerable to safe driving in unexpected situations or driving in the city due to deterioration of physical and cognitive functions in elderly drivers. The purpose of this study was to investigate the difference in driving behaviors according to age of self-drivers and to identify changes in physical function related to driving caused by normal aging. The subjects of the study included 75 healthy adults (21 persons aged 20-39 years, 40 persons 40-64 years, 14 persons 65 years old) who were self-driving and possessed a driver's license. Data included sex, dominant hand, medication, exercise, age, and driving time obtained by a self-reported questionnaire. In addition, this study measured steering, acceleration and braking using a Driver Test Station. Results of the study showed there was no significant difference in power test according to age group, but the total time of the timer test and the emergency brake test significantly differed according to age. The timer test and emergency brake test were completed fastest in young adults between 20 and 39 years old and completed slowest in elderly people 65 years old or over. Based on our study results, it is suggested that normal aging affects the perceptual-cognitive processes associated with driving behaviors.

• Journal of The Korean Association For Science Education
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• v.22 no.3
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• pp.571-585
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• 2002

This is one of the basic research for inspecting the possibility of the development of logical thinking capability to make possible formal thinking. The 5th grade students (n=306) in the elementary school were participated in this study. Performing the 6 variable-controlling activities in the 'Thinking Science' program for one semester, the SRT II test and the Variable-Controlling test were operated to examine the effects on the development of the variable-controlling ability by treatments, gender, and cognitive levels. Performing of the variable-controlling activities was highly successive on the development of students' variable-controlling ability. Although learning effect on the ability of identifying causal variable was moderate, the abilities of controlling experimental condition, measurement of variable, and identifying result variable were significantly developed. There was statistically significant difference by gender. Girls showed better performance all the time in both groups. Boys in the experimental group were getting better gradually, so the difference by gender was somewhat decreased. Examining the variable-controlling ability by cognitive levels, students in the experimental group show significant increase in all levels, especially the students in early, mid, and mature concrete level show substantial learning effects. The results of this study implied that the variable-controlling activities in the 'Thinking Science' could be effective for learning of variable-controlling and eventually for the development of logical thinking capability to make possible formal thinking.

• Journal of the Korean Chemical Society
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• v.48 no.1
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• pp.85-93
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• 2004

The purpose of this research was to investigate the change of argumentation of middle school students when they participated in argument tasks with CASE(Cognitive acceleration through science education) programs. Students argumentations were divided into two categories; 'explanatory argumentation' and 'dialogic argumentation'. Several argumentation components were used in their argumentation. Among argumentation components, claim and ground took place more than half of argumentation components. The percentage of 'dialogic argumentation' was lower than the percentage of 'explanatory argumentation'. The percentage of 'dialogic argumentation' was getting higher during CASE intervention. CASE programs had more effect on symmetric group than asymmetric group, however it was unstable. In general, participation ratio in argumentation of the formal operational student was high and the ratio in argumentation of the transitional student was getting higher.

• Journal of The Korean Association For Science Education
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• v.22 no.4
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• pp.696-705
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• 2002

The main purpose of this study is to investigate whether the correlational reasoning activities could improve middle school students' correlational reasoning abilities. The subjects were 8th grade students, and the correlational reasoning activities of the CASE(cognitive acceleration through science education) program was intervened to the experimental group(n=111) during science class while usual science instruction was given to the control group(n=55). The correlational reasoning test was administered before and after the intervention. The pre-test results showed that most of subjects performed poorly in correlation problems and no significant differences were found between the two groups. In the post-test, the experimental group showed enhanced performance while the control group did not. Therefore it can be concluded that CASE program activities help the students to improve correlational reasoning ability. However, the proportions of students gave correct response were not so high: 27% for the multiple-choice item and about 6% for the essay-type items.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2747-2752
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• 2003

This paper has develops a new framework to understand the human’s driving maneuver based on the expression as HDS focusing on the driver’s stopping maneuver. The driving data has been collected by using the three-dimensional driving simulator based on CAVE, which provides three-dimensional visual information. In our modeling, the relationship between the measured information such as distance to the stop line, its first and second derivatives and the braking amount has been expressed by the PWPS model, which is a class of HDS. The key idea to solve the identification problem was to formulate the problem as the MILP with replacing the switching conditions by binary variables. From the obtained results, it is found that the driver appropriately switches the ‘control law’ according to the following scenario: At the beginning of the stopping behavior (just after finding the stopping point), the driver decelerate the vehicle based on the acceleration information, and then switch to the control law based on the distance to the stop line.