• Korean Journal of Radiology
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• v.21 no.10
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• pp.1165-1177
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• 2020

Objective: To assess the feasibility of applying a deep learning-based denoising technique to coronary CT angiography (CCTA) along with iterative reconstruction for additional noise reduction. Materials and Methods: We retrospectively enrolled 82 consecutive patients (male:female = 60:22; mean age, 67.0 ± 10.8 years) who had undergone both CCTA and invasive coronary artery angiography from March 2017 to June 2018. All included patients underwent CCTA with iterative reconstruction (ADMIRE level 3, Siemens Healthineers). We developed a deep learning based denoising technique (ClariCT.AI, ClariPI), which was based on a modified U-net type convolutional neural net model designed to predict the possible occurrence of low-dose noise in the originals. Denoised images were obtained by subtracting the predicted noise from the originals. Image noise, CT attenuation, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively calculated. The edge rise distance (ERD) was measured as an indicator of image sharpness. Two blinded readers subjectively graded the image quality using a 5-point scale. Diagnostic performance of the CCTA was evaluated based on the presence or absence of significant stenosis (≥ 50% lumen reduction). Results: Objective image qualities (original vs. denoised: image noise, 67.22 ± 25.74 vs. 52.64 ± 27.40; SNR [left main], 21.91 ± 6.38 vs. 30.35 ± 10.46; CNR [left main], 23.24 ± 6.52 vs. 31.93 ± 10.72; all p < 0.001) and subjective image quality (2.45 ± 0.62 vs. 3.65 ± 0.60, p < 0.001) improved significantly in the denoised images. The average ERDs of the denoised images were significantly smaller than those of originals (0.98 ± 0.08 vs. 0.09 ± 0.08, p < 0.001). With regard to diagnostic accuracy, no significant differences were observed among paired comparisons. Conclusion: Application of the deep learning technique along with iterative reconstruction can enhance the noise reduction performance with a significant improvement in objective and subjective image qualities of CCTA images.

• International Journal of Contents
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• v.12 no.1
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• pp.25-43
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• 2016

An agent-centric event planning method is proposed for providing pedagogical experiences in an immersed environment. Two-level planning is required at in a macro-level (i.e., inter-event level) and an intra-event level to provide realistic experiences with the objective of learning declarative knowledge. The inter-event (horizontal) planning is based on search, while intra-event (vertical) planning is based on hierarchical decomposition. The horizontal search is dictated by several realistic types of association between events besides the conventional causality. The resulting schematic plan is further augmented by conditions associated with those agents cast into the roles of the events identified in the plan. Rather than following a main story plot, all the events potentially relevant to accomplishing an initial goal are derived in the final result of our planning. These derived events may progress concurrently or digress toward a new main goal replacing the current goal or event, and the plan could be merged or fragmented according to their respective lead agents' intentions and other conditions. The macro-level coherence across interconnected events is established via their common background world existing a priori. As the pivotal source of event concurrency and intricacy, agents are modeled to not only be autonomous but also independent, i.e., entities with their own beliefs and goals (and subsequent plans) in their respective parts of the world. Additional problems our method addresses for augmenting pedagogical experiences include casting of agents into roles based on their availability, subcontracting of subsidiary events, and failure of multi-agent event entailing fragmentation of a plan. The described planning method was demonstrated by monitoring implementation.

• Journal of The Korean Association of Information Education
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• v.16 no.2
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• pp.173-180
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• 2012

This study looks for the requirements for adaptive courseware and provides background for developing effective adaptive courseware. Most adaptive courseware does not adequately reflect the requirements of learners. If it properly reflected learners' requirements well, it could be used more effectively. therefore, this study analyzes and suggests the requirements of an adaptive courseware for pre-service teachers who are majoring in computer education. The study methods were factor analysis and frequency analysis through survey. The results show that the important elements of an adaptive courseware are a learning style designed according to individual differences as well as an instruction model appropriate to the subject domain. The study examined adaption by learner level, by learning objective, by learning style, by method of learning content, and by learning history in that order. Therefore while the most of adaptive courseware support learning style; we propose that the adaptive courseware will support learning objects and instruction model as well.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7599-7606
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• 2015

The objective of this study was to examine the correlations between smart phone addictions (SPA) and learning disorder (LD), attention deficit hyperactivity disorder (ADHD), and depression of post secondary level students, who were believed to have decent degree of self-commands. The correlation between the degree of smart phone addiction and learning disorder was 46 (p<0.001) and the correlation between the degree of smart phone addiction and ADHD was 48 (p<0.001). Meanwhile, the correlation between learning disorder and ADHD was 64 (p<0.001). From the multiple comparison of learning disorders, bothe the learning disorder and the ADHD of a group with lower degree of smart phone addiction showed mean differences that were more statistically significant than those of a group with higher degree of smart phone addiction. The depression of a group with lower degree of smart phone addition was also more statistically significant than that of a group with higher degree of smart phone addiction.

• Journal of Korean Elementary Science Education
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• v.35 no.3
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• pp.362-376
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• 2016

The purpose of this paper was to analyze the characteristics of Korean science curriculum and the differences with the other country. For this purpose, the USA was selected as the target country for comparison. The comparison focused on goals and contents in science curriculum document. The goals for science education in both countries were similar. But the goal setting level was different. Also, four objectives were suggested in Korean curriculum and nine objectives in the USA to achieve the general objective. Korean curriculum was composed of such grades system as 3rd & 4th grades, 5th & 6th grades and content area as 'materials and energy', 'life and the earth' in content system. And the USA composed in the such grade system as K, Grade 1, 2, 3, 4 and 5. Also the elements to be learned is suggested in the strand. And in the area of the earth and space in the Korean Curriculum, there are elements emphasized in the content area, cognitive area, context category and practical activities learning objective category. But the USA covered most of those elements evenly. Korean curriculum focused on learning of certain elements in certain grades, but the USA curriculum is to learn several elements evenly in every grade. It will be future topics of research to investigate the effect of curriculum with different emphasis of improving students' scientific knowledge and learning through further study.

• English Language & Literature Teaching
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• v.12 no.1
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• pp.159-181
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• 2006

The purpose of this paper is to examine the effectiveness of presentation-based instruction and to suggest a model of instruction targeted to the Korean intermediate level students learning English as a foreign language (EFL). To achieve this objective, the author examined how the acquisition of practical English through oral presentation would enhance the students' learning motivation, language abilities, and communicative competence in concrete situations. It was confirmed that the trained leader and systematic teaching and learning are needed to maximize the effects of presentation-based instruction. In doing so, the author compared and analyzed the collected data in order to support the validity of this teaching method. It was further pointed out that the teacher should have a close look at the roles of the presenter and learner in an effort to work out the usefulness of such an instruction model. The method of presentation in classroom settings would be a practical mode to attain the essential purpose of EFL teaching particularly to get over the drawbacks of Korean students' communicative competence. As a result, it would be an effective teaching method to meet the nation's long-standing demands for EFL education.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.6-8
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• 2004

The objective of this paper is to develop a powered wheelchair controller based on EMG for users with high-level spinal cord injury using a proportional control scheme. An advantage of EMG is relative convenience of acquisition by a surface electrode to users. Direction information can be easily extracted from two EMG channels and force information can be acquired by proportional relationship between the amplitude of EMG and user's power, respectively. Pattern classification algorithm is a threshold method with a supervised learning process. Furthermore, the emergency situation can be avoided using an interrupt function. We evaluated the performance of powered wheelchair controller by navigating a pre-defined path with three non-handicapped people. The results show the feasibility of EMG as an input interface for powered wheelchair and other devices for the seriously disabled.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.711-726
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• 2013

The purpose of this study was to investigate how congruently the learning objectives of Earth Science I textbooks match the 2009 revised Earth Science curriculum. For this purpose, we classified the learning objectives of curriculum and textbooks were into three factors including ability, cross-cutting concepts, and behavioral verbs. The text data were analyzed using the semantic network analysis method. The results are as follows. The learning objectives of textbooks with regard to ability factors mainly emphasized the cognitive and affective domain. In addition, the ability of inquiry performance was emphasized in the learning objective of the curriculum. The textbooks used various sub-frame of cross-cutting concepts in comparison with the curriculum. Both textbooks and curriculum used the term 'comprehension' the most as behavioral verbs. However, most behavioral verbs just remained at the level of cognitive system.

• Journal of the Korean earth science society
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• v.21 no.6
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• pp.655-662
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• 2000

According to the development of internet with Web, WBI has greatly influence on the present educational society. However, it is difficutly to design the web of the dynamic motions of graphics or animation using general programming technique based on high or low level language. Recently, Mecromedia Company supported a tool that is called Authoware which is the leading visual rich-media authoring solution for creating Web and online learning applications, to solve the problem easily. In the paper, using the the Authoware we tried to develop a web page about tidal variations due to sea level change and intertidal zone variations using the Authorware 5.1. To do this, we used the ocean survey data of Iho beach and the tidal level data based on Tidal Tables of Cheju harbor. The results showed that the Authorware was very useful to construct the simulation of tidal phenomena on web. Therefore, the Authorware can be applied to the simulation related with animation and dynamic motions for the other WBI objective.

• Journal of Oriental Neuropsychiatry
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• v.19 no.3
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• pp.101-115
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• 2008

Objective: The purpose of this study was to investigate the protective effects of Sam-Jeong-Hwan(SJH) on the animal model of depression induced immobilization stress. Method: The subject were divided into 4 groups(l. normal 2. saline solution administered during immobilization stress treatment 3. SJH of 100mg/kg administered 4. BKJ of 400mg/kg administered). Immobilization stress was treated for 1 hours on day. During 2 days of immobilization stress treatment, they were executed forced swimming test, passive avoidance test, elevated plus maze test. Corticosterone and ACTH in blood were measured. Results: In forced swimming test, SJH of 400mg/kg group showed decreased immobilization. In passive avoidance test, SJH of 400mg/kg group showed increased learning execution. In EPM test, SJH of 400mg/kg group showed decreased anxiety. In locomotor activity test, SJH groups showed significantly increased locomotor activity. Stress group showed significantly increase in serum level of corticosterone, SJH of 400mg/kg group showed decreased serum level of corticosterone. Stress group showed significantly increase in serum level of ACTH, SJH of 400mg/kg group showed decreased serum level of ACTH. Conclusion: These results suggest that Sam-Jeong-Hwan(SJH) is effective in the treatment of depression.