• The Journal of Korean Academy of Prosthodontics
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• v.46 no.3
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• pp.269-279
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• 2008

STATEMENT OF PROBLEM: Recently, various all-ceramic crowns fabricated with CAD/CAM systems have come into wide use in dental clinic. However, there are only few domestic studies on CAD/CAM restorations. PURPOSE: Purpose of this study was to compare the fidelity (absolute marginal discrepancy and internal gap) between various cores fabricated with different CAD/CAM systems (Procera system, Lava system, Cerec inLab system) and conventional metal cast core. MATERIALS AND METHODS: 10 cores per each system were fabricated. The absolute marginal discrepancies were measured using measuring microscope and digital counter. The internal gaps were calculated using a silicone paste. The results were statistically analyzed using the one-way ANOVA test and Tukey's HSD test. RESULTS: Within the limits of this study the results were as follows. 1. The absolute marginal discrepancies were $32.5{\pm}3.7\;{\mu}m$ for metal cast core, $72.2{\pm}7.0\;{\mu}m$ for Procera core, $40.8{\pm}5.4\;{\mu}m$ for Lava core, and $55.3{\pm}8.7\;{\mu}m$ for Cerec inLab core. The internal gaps were $38.4{\pm}5.7\;{\mu}m$ for metal cast core, $71.4{\pm}5.3\;{\mu}m$ for Procera core, $45.9{\pm}7.3\;{\mu}m$ for Lava core, and $51.8{\pm}6.2\;{\mu}m$ for Cerec inLab core. 2. The fidelity of metal cast core showed the smallest gaps, followed by Lava core, Cerec inLab core, and Procera core. CONCLUSION: The fidelities of 4 core groups were all within the clinically acceptable range ($120\;{\mu}m$).

• Journal of Digital Convergence
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• v.18 no.2
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• pp.483-487
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• 2020

In this study, the effects of suspension training according to the types of ground. Fourteen healthy male college students measured for the characteristics of core muscle activity in suspension training on two different types of grounds, normal flat and unstable ground using a gym ball. EMG (Electromyography) was exploited to measure the activity of the core muscles according to the types of the ground. Muscle activity of the abdominal muscles, external oblique muscles, internal oblique muscles, and lower lumbar standing muscles was measured. The variables in analyses were measured by the means of % MVC method to standardize the EMG signal according to the ground type for each core muscle. In order to verify the differences in core muscles according to the type of ground the paired t-tests were performed at the significance level of 0.05 (p<.05). As a result of measuring the activity of the core muscles according to the various types of grounds, the difference between muscle characteristics obtained in two different grounds did not appear to be statistically significant. However, the result is an important clue to reconsider the notion that the training effect on the unstable ground is generally superior to the effect on the stable ground in the core muscle training. The type of ground in the core muscle training has been found not to significantly affect the muscle activation according to the results of this study. Regardless of the type of exercise program, hence, the difference in muscle activation will not be insignificant even with the standardized program strengthening core muscles.

• Journal of Digital Contents Society
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• v.17 no.4
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• pp.243-255
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• 2016

The purpose of this study is to develop the components and design strategies of e-learning content for the development of interpersonal competency, one of NCS vocational core competencies. In order to standardize the educational curriculum and content of interpersonal competency, this study has referred to the educational handbook of NCS vocational core competencies that the Human Resources Development Service of Korea has developed. Based on such standardized content, e-learning content components and design strategies were extracted by analyzing related studies and e-learning cases as well as by conducting surveys and interviews with experts and instructors of the field. Applying components and design strategies extracted through those investigations, the e-learning content for the development of interpersonal competency was developed. Its design's validity and educational effect were evaluated by interviews and surveys with students, professors, and experts. The evaluation results show that the e-learning content was appropriately designed and was effective in learning interpersonal competency as one of NCS vocational core competencies.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.57-63
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• 2016

The purpose of this study is to draw implications about a practice of university faculty member's teaching reflection by considering the concept, process, and content of reflection as a theoretical basis of teaching reflection. The concept of reflection is based upon 'reflection-in-action' suggested by $Sch{\ddot{o}}n$, and the process and content of reflection is explained through Korthagen's Core Reflection model. The following three implications conclude: First, a faculty member should write a reflection journal by observing and reflecting consistently one's own behavior in a context of teaching. Second, the center for teaching and learning should provide an orientation and consultation about the content and process of teaching reflection. Finally, sharing lessons with the colleague faculty member is required to make an effective reflection for each faculty member.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.279-287
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• 2020

For effective clinical practice education, this study was conducted to find out the effects of learning practical subjects on the core competency and satisfaction level of clinical practice on nursing students. The research subjects were divided into groups that conducted four core nursing education classes eight hours a day for two weeks, and groups that received traditional lecture-oriented education, and a questionnaire was prepared and reported by themselves after 15 weeks of clinical practice. The collected data was analyzed using frequency, percentage, mean and standard deviation, chi-square test, and t-test using the SPSS 21.0 program. The findings supported the hypotheses in critical thinking propensity and clinical practice satisfaction, and the hypotheses in leadership, problem-solving and communication skills were rejected. The results of this study confirmed that practical training for strengthening core practical skills has a positive effect on the critical thinking tendency and clinical practice satisfaction of nursing students. Therefore, it can be used as an effective practical training arbitration in nursing education.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1470-1476
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• 2020

This paper describes a design of a lightweight security system-on-chip (SoC) suitable for the implementation of security protocols for IoT and mobile devices. The security SoC using Cortex-M0 as a CPU integrates hardware crypto engines including an elliptic curve cryptography (ECC) core, a SHA3 hash core, an ARIA-AES block cipher core and a true random number generator (TRNG) core. The ECC core was designed to support twenty elliptic curves over both prime field and binary field defined in the SEC2, and was based on a word-based Montgomery multiplier in which the partial product generations/additions and modular reductions are processed in a sub-pipelining manner. The H/W-S/W co-operation for elliptic curve digital signature algorithm (EC-DSA) protocol was demonstrated by implementing the security SoC on a Cyclone-5 FPGA device. The security SoC, synthesized with a 65-nm CMOS cell library, occupies 193,312 gate equivalents (GEs) and 84 kbytes of RAM.

• Journal of Practical Engineering Education
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• v.14 no.3
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• pp.565-572
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• 2022

Card sorting is a useful data collection method for understanding users' perceptions of relationships between items. In general, card sorting is an intuitive and cost-effective technique that is very useful for user research and evaluation. In this study, the core competencies of each field were used as competency cards used in the next stage of card sorting for course development, and the clustering results were derived by applying the K-means algorithm to cluster the results. As a result of card sorting, competency clustering for core competencies for each occupation in each field was verified based on Participant-Centric Analysis (PCA). For the number of core competency cards for each occupation, the number of participants who agreed appropriately for clustering and the degree of card similarity were derived compared to the number of sorting participants.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.4
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• pp.235-243
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• 2008

In this paper, a software-based Digital Radio Modiale(DRM) receiver is implemented on a Digital Signal Processor(DSP). DRM stands for the European radio broadcasting standard to bring AM radio into digital radio, designed to work at frequencies below 30MHz. DRM can offer various data services such as text messaging and slideshow services as well as audio services. The DRM receiver implemented on the Tensilica DSP core performs well at low signal strength indication of -102dBm.

• Journal of Technology Innovation
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• v.12 no.3
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• pp.205-227
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• 2004

This paper examined the leapfrogging of Korean Digital TV Industry in the midst of digital Revolution. Despite the lack of sufficient capability and core knowledge base, the Korean firms succeeded in the catching up forerunner firms in the Digital TV industry. The reasons of the success of Korean firms were as follows. Firstly, the Korean firms had some complementary asset, such as the experience of producing analog TV, and were able to develop the prototype digital TV given the accesses to the foreign knowledge via overseas R&D posts and acquisition of a foreign company. Secondly, the Korean firms were not locked in the analog technologies. As a follower, they had little sunk cost on the existing analog technologies. Thirdly, New mode of innovation, such as National R&D program for the development of HDTV and ASIC, were used as a tool for the mobilization of scarce knowledge base of digital technologies and the sharing the risks of development of path-breaking new technologies.

• East Asian mathematical journal
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• v.39 no.4
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• pp.437-454
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• 2023

The core of the change in the era of the 4th industrial revolution is the change in the base of 'digital technology'. These changes are incomparably large and are expected to have a more important impact on our lives than ever before. One of the major inflection points in the transition to the digital era is the education field, and IT technology has become an essential element in the educational field. Accordingly, this study examines domestic research trends related to the educational environment based on digital technology. Then, we would like to provide implications for the establishment of a digital-based educational environment that will change in the future. To this end, Semantic network analysis has been conducted to quantitatively structure text data obtained from studies related to digital technology in the field of mathematics education over the past 10 years, and the discussion will continue based on the results.