• Journal of Korea Multimedia Society
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• v.23 no.4
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• pp.595-602
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• 2020

We propose a generative probabilistic model with Dirichlet prior distribution for topic modeling and text similarity analysis. It assigns a topic and calculates text correlation between documents within a corpus. It also provides posterior probabilities that are assigned to each topic of a document based on the prior distribution in the corpus. We then present a Gibbs sampling algorithm for inference about the posterior distribution and compute text correlation among 50 abstracts from the papers published by IEEE. We also conduct a supervised learning to set a benchmark that justifies the performance of the LDA (Latent Dirichlet Allocation). The experiments show that the accuracy for topic assignment to a certain document is 76% for LDA. The results for supervised learning show the accuracy of 61%, the precision of 93% and the f1-score of 96%. A discussion for experimental results indicates a thorough justification based on probabilities, distributions, evaluation metrics and correlation coefficients with respect to topic assignment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.2942-2960
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• 2022

The core of cognitive radio is the problem concerning intelligent decision-making for communication parameters, the objective of which is to find the most appropriate parameter configuration to optimize transmission performance. The current algorithms have the disadvantages of high dependence on prior knowledge, large amount of calculation, and high complexity. We propose a new decision-making model by making full use of the interactivity of reinforcement learning (RL) and applying the Q-learning algorithm. By simplifying the decision-making process, we avoid large-scale RL, reduce complexity and improve timeliness. The proposed model is able to find the optimal waveform parameter configuration for the communication system in complex channels without prior knowledge. Moreover, this model is more flexible than previous decision-making models. The simulation results demonstrate the effectiveness of our model. The model not only exhibits better decision-making performance in the AWGN channels than the traditional method, but also make reasonable decisions in the fading channels.

• The Journal of the Korea Contents Association
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• v.13 no.12
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• pp.1048-1057
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• 2013

This study aims to evaluate the effect on the academic achievement and satisfaction of the learner's prior knowledge level and segmenting time of video lectures in an learning environment using smartphones. Depending on the level of prior knowledge, learners were divided into two groups of the upper 35% and the lower 35%. Each group was offered video lectures by a 5-min, 10-min, 15-min, and 20-min length. As a result, a high level of prior knowledge only had a positive effect on the academic achievement. With respect to the segmentation time of video lectures, 10-min, 15-min lectures were effective to the academic achievement and 15-min, 20-min lectures influenced positively the learners' satisfaction. Moreover, the interaction between the level of learners' prior knowledge and the segmentation time of video lectures only had an impact on their academic achievement. The results of the simple effect analysis conducted to examine the effect of interaction carefully show that 15-min, 20-min video lectures are more effective for the upper 35% in prior knowledge and 10-min ones are better for its' lower 35%. In a nutshell, these findings suggest that the high-prior knowledge groups could be provided with a longer video lectures, and furthermore, 5-min video lectures are not adequate in a mobile learning environment with smartphones.

• Journal of Families and Better Life
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• v.34 no.2
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• pp.1-14
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• 2016

This study attempted to investigate household's private educational expenditure that aggravates a burden on households by using the data from the 2014 Private Education Survey published by Statistics Korea. The effects of purposes of private education and participation in an after school program that is pushed by the government on household's private educational expenditure were analyzed. The major findings were as follows. First, the major purposes of private education lean toward preparing to enroll in school and relieving parents'uneasiness rather than prior learning Second, according to the purposes of private education, the differences of the private educational expenditure were verified. Households spend the highest level of private educational expenditure for the purpose of preparing to enroll in school contrary to the lowest level, which was for the purpose of compensatory learning. Third, participation in an after school program that is regarded as a method of moderating households' private education burden, had a positive effect on reducing private educational expenditure. Forth, private educational expenditure was influenced by the purposes of private education and participation in an after school program. In 2014, the Korean government enforced a law that prohibits schools'education in advance (prior learning) and regulates private educational institutes'advertisement about prior learning. Regarding this regulation, this study aimed to investigate the purposes and expenditure of private education to provide an empirical reference to determine the improvement of related policies.

• Research in Mathematical Education
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• v.13 no.4
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• pp.297-307
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• 2009

This research examined intuitive knowledge of 6th grade students in Israel prior to the formal learning of percentages in school. In other words. the research investigated knowledge of basic concepts and familiarity with the usage of percentages in daily life. Results have shown that students are familiar with the concept of percentages and thai some students are able to handle simple problems composed of common percentages (50% and 25%). However, it was also found that many students had misconceptions that should be taken into account while the subject has been taught.

• East Asian mathematical journal
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• v.25 no.3
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• pp.247-262
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• 2009

Permutation and combination are the part of mathematics which can be introduced the pliability and diversity of thought. In prior studies of permutation and combination, there treated difficulties of learning, strategy of problem solving, and errors that students might come up with. This paper provides the method so that meaningful teaching and learning might occur through the systematic approach of permutation and combination. But there were little prior studies treated counting numbers that basic of mathematics' action. Therefore this paper tries to help the understanding of permutation and combination with the process of changing from informal knowledge to formal knowledge.

• Korea Journal of Hospital Management
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• v.24 no.4
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• pp.70-84
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• 2019

Purposes: Despite a lot of prior studies on psychological empowerment on positive outcomes, the objectives of this paper were to examine the role of psychological empowerment on informal learning and the mediation role of informal learning between psychological empowerment and outcome variables focused upon physical therapists working in hospital industry. Methodology: Using survey methods, the data were collected from 198 physical therapists who have worked in Ulsan city and attended in annual meeting. Findings: Results showed that psychological empowerment predicted informal learning positively but differences in mediational mechanism. Specifically, the path between psychological empowerment and proactive behavior partially mediated but no mediating effect between psychological empowerment and helping behavior. This study identified the main role of psychological empowerment on informal learning, and it expands on positive functions of the concept to learning area in organizations. The other results help advanced understanding of differential mechanism through informal learning in the process between psychological empowerment and both outcomes. Practical Implications: The current study contributes to expend the area of prior findings on psychological empowerment to learning activities implemented by individual volunteer effort. For hospitals operating the teams of physical therapy, the significance for considering psychological empowerment is highlighted as for individual growth related to job and for change behavior in the individual level.

• Educational Technology International
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• v.16 no.2
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• pp.183-200
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• 2015

This study investigated the effect of learning achievements and cognitive load according to different types of presenting learning materials and epistemological beliefs (EB). Learning achievements in this study were composed by retention and transfer of ill-structured problem. A total of 80 college students participated in the study. Prior to the learning, students were guided to fill out a questionnaire regarding epistemological beliefs and a prior knowledge test. The students of each group studied with a different type of reading material: full text (FT), full text including key questions (KeyFT) and full text including a concept map (CmFT). After a session of study was finished, they were asked to complete the posttest: retention and transfer. The results showed that there was a significant difference in transfer achievements. CmFT outperformed higher scores than the other types. There was no significant difference in retention among the groups. It is strongly believed that the types of presenting learning materials may have affected the understanding of ill-structured problem solving skills. Students with sophisticated EB showed higher achievements on retention and transfer than naive-EB and mixed-EB. Even though the data showed decrease of the cognitive load on the type of materials and EB, there were no significant differences on the cognitive load. We should consider a positive effect of types of presenting learning materials and EB enhancing capabilities of solving ill-structured problems in real life.

• Journal of Technology Innovation
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• v.7 no.1
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• pp.78-97
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• 1999

This study aims at analysing the role of crisis in the technological innovation. It has been taken for granted that organizational crisis has detrimental effects on the survival of organizations. But recent studies showed that organizational crisis has positive effects on organizational learning. They argued that crisis would provide a opportunities for reflecting the effectiveness of existing organizational routine. This study analyses the process and role of crisis in the development of CDMA mobile communication system and argues that crisis has effects on technological innovation when organizations have prior knowledge base which can be exploited in organizational learning. Secondly, it is argued that crisis can result in organizational transformation which facilitates organizational learning by integrating prior knowledge base and new knowledge. Thirdly, it is suggested that crisis may be good facilitator for organizational learning in case of competence-enhancing innovation rather than competence-destroying innovation.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.83-92
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• 2013

An emerging learning method, flipped learning, has gained much interest lately due to its process involving prior study followed by the students' classroom involvement, which direction matches that of the current educational policy that emphasizes self-directed learning. This study investigated the concept of flipped learning and explored ways to develop instructional design models that utilize it. Flipped learning is not a model that has been recently developed, as it uses the format of blended learning with the introduction of a new concept of prior learning that allows students to learn in advance through online lessons and video clips related with the classroom content to be covered. During class time, individualized supplementary or in-depth study is conducted on the basis of the students' prior learning. The main considerations for designing flipped learning are a flexible classroom environment, a shift in learning culture, intentional classroom content, and educators equipped with professional capability. The research proposes the development of instructional design models for flipped learning pursuant to such concept and considerations. Through this research, the concept of flipped learning can be comprehended; furthermore, flipped learning can be utilized more effectively in the teaching and learning environment.