• Journal of Korean Elementary Science Education
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• v.30 no.4
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• pp.615-623
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• 2011

The purpose of this study was to analyse of the effects on students' leaning types through the Creative Problem Solving Teaching Model in elementary science class. The results of this study were as follows; 1. experimental group in creative problem solving, scientific inquiry skills and academic achievement was higher than control group which was statistically significant (p<.05). 2. for the students' learning type the experimental group was distributed to accommodators (35.7%), divergers (25.0%), convergers (25.0%) and assimilators (14.3%). 3. after the program treatment, assimilator type group students in creative problem solving were higher than other type group students. 4. diverger and assimilator group students in academic achievement, diverger group students in scientific inquiry skills, and accommodator group students in scientific attitude were higher than other groups.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.12
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• pp.640-645
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• 2006

A 22.9kV/50MVA class high temperature superconducting(HTS) power cable system was developed in Korea. For the optimization of electrical insulation design for a HTS cable, it is necessary to investigate the ac breakdown impulse breakdown and partial discharge inception stress of the liquid nitrogen/laminated polypropylene paper(LPP) composite insulation system. They were used to insulation design of the model cable for a 22.9kV class HTS power cable and the model cable was manufactured. The insulation test of the manufactured model cable was evaluated in various conditions and was satisfied standard technical specification in Korea. Base on these experimental data, the single and 3 phase HTS cable of a prototype were manufactured and verified.

• Korean Journal of Child Studies
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• v.26 no.4
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• pp.189-207
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• 2005

This study examined the effects of picture storybook making activities with computer plays on children's storytelling ability and creativity. Seventy 5-year-old children from two day-care classes participated in this eight-week program. The experimental class used the computer software of 'Stanley's Sticker Stories.' The comparison class used paper and pencil. Data analysis was implemented by ANCOVA and t-test. Significant differences were found between the experimental and comparison groups in story telling ability by story structure, imagination, vocabulary, sentence structure, and creativity showing that picture storybook making activities with the computer was more effective than traditional picture storybook making activities.

• Journal of Korean society of Dental Hygiene
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• v.10 no.4
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• pp.655-661
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• 2010

Objectives : This study is aimed to prevent the damage to the inferior alveolar nerve during the orthognathic surgery. Methods : The control group consist of 50 patients with class I occlusion. The experimental group consist of 50 patients with class III malocclusion. The cepalometric radiography was used to evaluate the position of the mental foramina. Results : In the first, mental foramen position of class III was more inferior 0.85 mm in the distance between base of mandible and mental foramen. But the distance between occlusal plan and mental foramen had not statistically significant. Secondly, mental foramen location of Mandibular Prognathism was more anterior 0.91 mm in the distance between coronal plane of mandible included pogonion point and mental foramen. Also, the distance of occlusal-coronal plane of mandible included central incisor and mental foramen had statistically significant. The mental foramen location of class III was more anterior 4.81 mm than class I patients. Conclusions : The result of this study could help the clinicians to apprehend fundamental data with various facial skeletal types for any related researches about the location of the mental foramina for other purposes.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.201-211
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• 2017

This study provided a rubric prior to the performance of a task in a coding class and aimed to verify its effect. As for the research contents, this study redesigned the rubric developed in the preceding studies for the purpose of this study, presented that to the students and conducted a verification of its effects on the computer efficacy and academic achievement of the students who participated in the experiment, conducting a class. For this purpose, with 41 students in an experimental group, to which the rubric was presented to conduct the class and 39 students in a control group to which the rubric was not presented to conduct the class, this study conducted a six-week class and conducted a survey on their self-efficacy in the computer and a test to measure their academic achievement before and after the experiment. As a result, there were more positive effects on both computer efficacy and academic achievement in the group to which a rubric was presented and in which a rubric evaluation was conducted than in the control group. Through the result of this study, it was noted that the evaluation method presenting more specific and more detailed standards for performance and the level of the standards would have positive impacts on the learners' learning.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1009-1011
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• 2001

This paper presents a new hybrid control scheme using Active-Clamped Class-E (ACCE) inverter of induction heating(IH) jar for high power applications. The proposed hybrid control scheme has characteristics, which act as class-E inverter at lower switch voltage and ACCE inverter at higher switch voltage than reference voltage of the main switch by feeding back voltage one as well as advantages of conventional ACCE inverter such as zero-voltage switching(ZVS) of the main switch and the reduced switch voltage due to the clamping circuit. Moreover, the proposed control method makes higher output power than conventional ACCE inverter control one since ACCE inverter is operated like class-E inverter at low voltage condition. The principle of the proposed control are explained in detail and the validity of the proposed control scheme is verified through the several interesting simulated and experimental results.

• Journal of The Korean Association of Information Education
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• v.21 no.5
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• pp.537-545
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• 2017

This paper presents the results of adopting pair programming practices in an introductory university programming course. The effectiveness of pair programming is analyzed by comparing the performance and survey data gathered from the experimental class that adopted the practice to those from the control class that did not. An analysis of the performance data found that pair programming improved student performance; however, not all students in the pair programming class benefited from the practice as only some students showed clear improvements in learning outcomes. The survey showed that the specific method for matching students into pairs is a critical factor affecting their performance and satisfaction. Based on the lessons learned from this pair programming class, I propose some suggestions and guidelines for applying pair programming to programming classes including 'pair matching'.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.368-391
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• 2018

Face recognition (FR) with a single sample per person (SSPP) is common in real-world face recognition applications. In this scenario, it is hard to predict intra-class variations of query samples by gallery samples due to the lack of sufficient training samples. Inspired by the fact that similar faces have similar intra-class variations, we propose a virtual sample generating algorithm called k nearest neighbors based virtual sample generating (kNNVSG) to enrich intra-class variation information for training samples. Furthermore, in order to use the intra-class variation information of the virtual samples generated by kNNVSG algorithm, we propose image set based multimanifold discriminant learning (ISMMDL) algorithm. For ISMMDL algorithm, it learns a projection matrix for each manifold modeled by the local patches of the images of each class, which aims to minimize the margins of intra-manifold and maximize the margins of inter-manifold simultaneously in low-dimensional feature space. Finally, by comprehensively using kNNVSG and ISMMDL algorithms, we propose k nearest neighbor virtual image set based multimanifold discriminant learning (kNNMMDL) approach for single sample face recognition (SSFR) tasks. Experimental results on AR, Multi-PIE and LFW face datasets demonstrate that our approach has promising abilities for SSFR with expression, illumination and disguise variations.

• International Journal of Concrete Structures and Materials
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• v.8 no.4
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• pp.315-326
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• 2014

This study evaluates the dosages of Class F fly ash, lithium nitrate and their combinations to suppress the excessive expansion caused by alkali-silica reactivity (ASR). In order to serve the proposed objective, the mortar bar specimens were prepared from (1) four dosages of Class F fly ash, such as 15, 20, 25 and 30 % as a partial replacement of Portland cement, (2) up to six dosages of lithium nitrate, such as lithium-to-alkali molar ratios of 0.59, 0.74, 0.89, 1.04, 1.19 and 1.33, and (3) the combination of lithium salt (lithium-to-alkali molar ratio of 0.74) and two dosages of Class F fly ash (15 and 20 % as a partial replacement of Portland cement). Percent contribution to ASR-induced expansion due to the fly ash or lithium content, test duration and their interaction was also evaluated. The results showed that the ASR-induced expansion decreased with an increase in the admixtures in the mortar bar. However, the specimens made with the both Class F fly ash and lithium salt produced more effective mitigation approach when compared to those prepared with fly ash or lithium salt alone. The ASR-induced expansions of fly ash or lithium bearing mortar bars by the proposed models generated a good correlation with those obtained by the experimental procedures.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.97-105
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• 1990

When conventional root canal treatment is failed or contraindicated, retrograde root canal filling following apicoectomy is a valuable procedure, aimed at hermetically sealing the root canal against leakage of irritants from the canal into the periapical tissue. In this in vitro investigation, to analyze apical microleakage electrochemically in teeth with different retrograde filling materials and preparation types, single - rooted tooth was cut 2mm from the apex and each Class I and Slot preparation was prepared. Experimental groups : Group 1. Amalgam filling with cavity varnish in Class I preparation Group 2. Scotchbond 2+Silux filling in Class I preparation Group 3. Gutta percha filling with ZOE cement in Class I preparation Group 4. Amalgam filling with cavity varnish in Slot preparation Group 5. Scotchbond 2+Silux filling in Slot preparation Each specimens was immersed in 1% solution of KCl, and applied a potential of 9V external power supply. Measurements of the current flow were obtained at 1, 2, 3, 7, 9, 12, 14, 18, 21, 25 and 28 day after immerson. Marginal microleakage were compared and evaluated. The results were as follows ; 1. The group filled with composite resin with dentin bonding agent shows lower apical microleakage value than the group filled with amalgam following varnish application (P<0.01). 2. In the group filled with gutta percha, apical microleakage value was the hightest 3. There was no significant difference between Class I cavity and Slot type cavity regardless of the used materials.