• Journal of The Korean Association For Science Education
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• v.27 no.1
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• pp.18-27
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• 2007

This study examined the influences of cognitive conflict and non-cognitive variables induced by a discrepant event on process of conceptual change, and the processes that a discrepant event lead to situational interest. Seventh graders participated in this study. A preconception test was administered to select students possessing misconceptions about density. The tests of cognitive response and situational interest to a discrepant event were administered. After learning with a CAl program, the tests assessing attention and effort allocated to the CAl, and conceptual understanding were also administered. A path analysis revealed that cognitive conflict induced by a discrepant event caused situational interest, which in turn increased attention and/or effort and thus, resulted in conceptual change. The results of the path analysis on the processes in which a discrepant event led to situational interest suggested that novelty may be a primary source of situational interest. Novelty influenced situational interest directly as well as through attention demand, exploration intention, and instant enjoyment. Moreover, novelty exerted a direct effect on challenge, which in turn had negative effects on instant enjoyment directly as well as through cognitive conflict, and thus, decreased situational interest. However, the path coefficients of the latter were relatively smaller than those of the former. Educational implications are discussed.

• Journal of The Korean Association For Science Education
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• v.27 no.4
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• pp.354-365
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• 2007

The purpose of this study was to understand the undergraduate students' response characteristics by their cognitive conflict levels and result predictions when they were confronted with the learning tasks of action & reaction and electric circuits. The 147 engineering college students who were enrolled at the introductory physics classes were selected as the subjects for this study. The students were grouped by cognitive levels and result predictions. First, in action and reaction task, the trend of suspecting experimental results and finding the reasons was dominant; however, in electric circuits, the trend of accepting the results was dominant. Second, the reasons for the responses on the subcategories of cognitive conflict were different by the level of cognitive conflict. The responses were influenced by students' preexisting knowledge, former experiences, learning habits, learning motivation, and epistemological beliefs, etc. The high conflict group recognized what they do not consider and was positive to reappraise their preconceptions, while the low conflict group showed the tendency of accepting the situation without doubt and low interest on learning physics. In conclusion, students responses showed differences in cognitive conflict levels, result predictions and presented conflict tasks. The research results, especially the response characteristics, suggest that more research on effective cognitive conflict strategies appropriate for different tasks and students' conflicts are necessary for effective physics teaching.

• Journal of the Korean Chemical Society
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• v.46 no.1
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• pp.76-82
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• 2002

This study investigated the effects of assigning cognitive roles, a method that may promote verbal interaction in knowledge-building processes, in small-group discussion for science concept learning. Two classes (62 students) of 7th-graders respectively received a concept learning instruction through small-group discussion with assigned cognitive roles (CR) asking to explain and contradict one's idea and to synthesize and conciliate group's idea, and a concept learning instruction through small-group discussion with no specific assigned roles (NSR), for 9 class periods. After the instructions, the tests of achievement, conceptions, the perceptions on science learning environments, and the perceptions toward small-group discussion were administered. ANCOVA results revealed that low-achievers in the NSR group performed significantly better than those in the CR group. Similar tendency was also found in the scores of the conceptions test. Two groups did not differ significantly in the perceptions on science learning environments and toward small-group discussion.

• Journal of Science Education
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• v.36 no.2
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• pp.251-262
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• 2012

In this study, we develop 15 learning programs to enhance the variable identification and control abilities for the middle school students and analyze the effect of the programs applied to the class. To increase the learning effect of the variable identification and control abilities, we design the programs so that the students can monitor their thinking processes and also they can evaluate the results from their cognitive activities objectively. We analyze the effect of the programs applied to the class and the results show that the test group, which uses the program, marks higher scores in the variable identification abilities compared to the control group. Also, the test group has the increased level of logic to control the variables. Especially, the effect is higher with the students who do not have any logic to control the variables. From the results, we know that it is possible to improve the variable identification and control abilities of the students through the meta-cognitive learning programs developed by us. Furthermore, the results show that the score of variable control abilities positively correlate with that of meta-cognitive level. It means that the meta-cognitive strategy meaningfully increases the variable control abilities of middle school students.

• Korean Journal of Childcare and Education
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• v.7 no.3
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• pp.165-187
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• 2011

This study was aimed to explore the effect of the physical science activity based on the constructivism on young children's scientific process skills and scientific attitudes, cognitive self-esteem. The subjects consisted of 20 five-years-old children of experimental group and 20 children of control group. Children of experimental group conducted the physical science activity based on the constructivism for total six weeks. As a result of study, children who experimental group showed significant result in the scientific process skill, scientific attitude, cognitive self-esteem. The educational implications of these indicate that we need to actively develop programs to increase scientific process skills and scientific attitude, cognition self-esteem of young children through teacher's education.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.220-224
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• 2005

The purpose of the present study is to investigate the effects of long-term exercise program on exercise capacity and cognitive function (MMSE) in male patients with dementia. 24 male patients were divided into two experimental groups : the exercise group (n=12) and the control group (n=12). The exercise group participated in regular exercise program for 12 months, and their exercise capacity (cardiopulmonary function, muscle strength, muscular endurance, flexibility, balance, agility) and MMSE (Mini-mental state examination) levels were evaluated at baseline (pre), after 6 months (mid) and after 12 months (post). The subjects carried on group-exercise of $VO_{2}max\;30\~60\%$, $30\~60$ minute a day, $2\~3$ times per week. Statistical techniques for data analysis was paired samples t-test. The level of statistical significance was ${\le}.05.$ The results of this study were summarized as follows: In the exercise group, there were significant differences in cardiopulmonary function, muscle strength, muscular endurance and MMSE at the times of pre & mid and pre & post, there were significant differences in balance and agility at the time of pre & post only, whereas there was no significant difference in flexibility following the long-term exercise. In the control group, there were no significant differences in all the times. Based on the results of this particular study, one year exercise program increases on the cognitive function & exercise capacity in male patients with dementia.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1208-1222
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• 2014

Due to the low utilization and scarcity of frequency spectrum in current spectrum allocation methodology, cognitive radio networks (CRNs) have been proposed as a promising method to solve the problem, of which spectrum sensing is an important technology to utilize the precious spectrum resources. In order to protect the primary user from being interfered, most of the related works focus only on the restriction of the missed detection probability, which may causes over-protection of the primary user. Thus the interference probability is defined and the interference-aware sensing model is introduced in this paper. The interference-aware sensing model takes the spatial conditions into consideration, and can further improve the network performance with good spectrum reuse opportunity. Meanwhile, as so many fading factors affect the spectrum channel, errors are inevitably exist in the reporting channel in cooperative sensing, which is improper to be ignored. Motivated by the above, in this paper, we study the throughput tradeoff for interference-aware cognitive radio networks over imperfect reporting channel. For the cooperative spectrum sensing, the K-out-of-N fusion rule is used. By jointly optimizing the sensing time and the parameter K value, the maximum throughput can be achieved. Theoretical analysis is given to prove the feasibility of the optimization and computer simulations also shows that the maximum throughput can be achieved when the sensing time and the parameter of K value are both optimized.

• Journal of Communications and Networks
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• v.14 no.2
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• pp.162-168
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• 2012

This paper considers the scenario in which a set of nodes share a common channel. Some nodes have a rechargeable battery and the others are plugged to a reliable power supply and, thus, have no energy limitations. We consider two source-destination pairs and apply the concept of cognitive radio communication in sharing the common channel. Specifically, we give high-priority to the energy-constrained source-destination pair, i.e., primary pair, and low-priority to the pair which is free from such constraint, i.e., secondary pair. In contrast to the traditional notion of cognitive radio, in which the secondary transmitter is required to relinquish the channel as soon as the primary is detected, the secondary transmitter not only utilizes the idle slots of primary pair but also transmits along with the primary transmitter with probability p. This is possible because we consider the general multi-packet reception model. Given the requirement on the primary pair's throughput, the probability p is chosen to maximize the secondary pair's throughput. To this end, we obtain two-dimensional maximum stable throughput region which describes the theoretical limit on rates that we can push into the network while maintaining the queues in the network to be stable. The result is obtained for both cases in which the capacity of the battery at the primary node is infinite and also finite.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.15-26
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• 2008

Recently, Internet Protocol TV technology has a latent power for searching information by using internet-connected interactive TV media. It is hard to browse and search web site conveniently since the visual and input devices are not sufficient for navigating through the websites. Zoomable user interface is a possible solution that may reduce users' task load and improve their performance. In this paper, we made three types of web browsers as scroll, physical zooming and semantic zooming type. Fifteen participants asked to do searching tasks and their task time, accuracy and subjective responses are recorded. In the result, though scroll type is evaluated more efficient than other types in task time and accuracy since participants are familiar with scroll type interface, semantic zooming type is highly rated in subjective responses such as perceived searching efficiency, satisfaction and joyfulness. This result implied semantic zooming is a possible solution which is improving user experience of searching websites using Internet Protocol TV.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.05a
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• pp.604-607
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• 2018

From the last past decade, the Internet of Thing (IoT) area has attracted a lot of attention from researchers. It is said to be a promising technology with great impact in people life, since it redefines the relationship objects have with Human and between themselves. It allows objects to gather data from the real world and communicate with others through the internet. This enabled many opportunities for service providers, companies, factories, environmental monitoring, healthcare, smart cities, and soon. Therefore, today, IoT is densely used in various domains of life, and knows an exponential growth. However, although many advancements have been achieved, several challenges keep causing issues and still need to be overcome. This paper gives an overview on the current trend issues in IoT on which researchers are focusing. It's also explores different proposed frameworks to allow the application of cognitive computing as an integrated process of an Internet of things (IoT) systems, to bring a great advanced in the way machine may communicate with human and their surroundings. This is known as cognitive IoT (CIoT), which allows machines to produce a human-like behavior, then providing enhanced level of capabilities to IoT.