• The Journal of Korean Academy of Prosthodontics
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• v.24 no.1
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• pp.55-65
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• 1986

An in vitro study was performed to evaluate adaptation of custom direct, custom indirect, and prefabricated post system on 15 extracted upper central incisors. 15 specimens were prepared and equally devided into 3 groups under random sampling. Each group of 5 cast posts was made with custom direct, custom indirect, and prefabricated post core method. Gap between inner wall of the dentin and outer wall of the cast post was measured on electron microphotographic prints at x500 magnification. The result were as follows ; 1. No significant difference of adaptation at cervical portion was found between each method. 2. Prefabricated post core method had poor adaptation compared with other methods. 3. Even distribution of adaptation was found in custom direct method between each portion. 4. Prefabricated post core method showed remarkable difference in adaptation between each portion.

• KIEAE Journal
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• v.10 no.6
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• pp.3-10
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• 2010

The subject is to find green roofs' location as stepping stones in green-network in fine scale. The study site is Junggu, Seoul, which has core areas(Bukaksan and Namsan) and green areas(parks, etc.). Through literature review, the closer to core areas and green areas, target species reach green roof easier, and target species must be avifauna(flying species) and high class in food chain, because of possibility of reaching. So, Great Tits, inhabited in Namsan and urban bird, is target species. The location standard of green roofs, realized birds' reaching distance, consists of home range(horizontal range and vertical range) and roof-greening capable area. The green roofs' distribution of location was resulted through GIS analysis of feasible site finding, and classified with weight of score. In discussion, Namsan gives more effect to locate green roofs than Bukaksan does and selected buildings which are grouped in some parts need to be managed with group, green roof district.

• Electronics and Telecommunications Trends
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• v.36 no.6
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• pp.25-35
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• 2021

ATSC 3.0 is a next-generation terrestrial broadcasting standard that provides various functions and improved performance compared to the existing ATSC 1.0 High Definition standard. Based on the ATSC 3.0 broadcast system with IP-centric transport and coherence, it can provide personalized and personalized interactive services to TV viewers. However, the broadcasting system still has a structural limitation in that the service is deployed separately from broadcasters who are allocated a specific frequency and is expected to have different spectrum allocation for each market. To overcome this structural limitation and provide improved services compared with the current ATSC 3.0, preliminary studies were conducted to apply the core network concept of a communication network (particularly 5G) to ATSC 3.0 broadcasting. Finally, in february of this year, the ATSC TG3/S43 group for the development of the ATSC 3.0 Broadcast Core Network (BCN) standard was launched. This paper describes the background and current status of BCN standardization by ATSC TG3/S43, and future standardization prospects.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.5
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• pp.81-94
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• 2022

This study analyzed the effect of the entrepreneurship planning course provided by an women's university in Seoul on the enhancement of the core competencies of entrepreneurship of university students. To this end, pre- and post-test of core entrepreneurship competency were conducted on 63 female university students (32 in experimental group, 31 in control group) and then the results were analyzed. The course in which the experimental group participated was a team-based project learning course and it required a team of three people to draw an entrepreneurship plan containing social problem solving as the final result. The course was operated for a total of 8 weeks. To measure the level of entrepreneurship core competency in the pre- and post- test, the survey tool that was developed by the Ministry of Education and Korea Entrepreneurship Foundation (2020) was used. This tool composed by 'value creation', 'challenge', 'self-directed', and 'group creativity' competencies. As analyses methods, i) covariance analysis was performed using the pretest as a covariate, and then a two-way ANOVA was performed with treatment (experimental group, control group) and time point (pre test, post test) as two independent variables. Results show while there was no significant difference between the experimental group and the control group in the value creation competency, it significantly contributed to the enhancement of challenge, self-directed, and collective creativity competencies. Based on these results, implications and limitations were discussed, followed by future research direction.

• Journal of Oriental Neuropsychiatry
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• v.30 no.3
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• pp.165-175
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• 2019

Objectives: This study was conducted to investigate the emotional characteristics of the patients within one year after stroke using the Core Seven Emotions Inventory-Short Form. Methods: It analyzed the medical records of 39 stroke patients who had visited W University hospital and completed the Core Seven-Emotions Inventory-Short Form (CSEI-S), the K-MBI, the PWI-SF, and the HADS. Patients data were analyzed by descriptive analysis, frequency analysis, the Mann-Whitney U test, and the nonparametric test of the CSEI according to the period of stroke onset in patients and Spearman's correlation analysis using the SPSS (Statistical Package for the Social Science, IBM, United States of America) Version 23.0. Results: First, in the case of depression, all subjects were in the danger group, although more than half of the joy, anger, thinking, sadness and fear were included in the normal group in the shortening of the key seven-point scale. Secondly, in measuring the social and psychological stress and hospital anxiety and depression, social and psychological stress were indicated to be a potential danger group, while anxiety and depression were shown to be a healthy group. Thirdly, the emotional characteristics were explored according to the sub-factor of the shortening of the key seven-figure emotional scale after being classified within two months, between two and six months and over six months depending on the duration of the outbreak. As a result, statistically significant, Joy was the highest score over six months and the lowest score between two and six months. On the other hand, the case of depression was depicted to be significantly lower at over six months, and was highest between two and six months. Finally, the correlations on each scale were statistically significant. Conclusions: This study provided that the CSEI-S can be used to simply to measure the emotions of patients according to the period of the onset of stroke in the clinical scene.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.383-389
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• 2009

The purpose of this study was to investigate the fracture resistance of crown-root fractured teeth repaired with dual-cured composite resin and horizontal posts. 48 extracted human premolars were assigned to control group and three experimental groups. Complete crown-root fractures were experimentally induced in all control and experimental teeth. In the control group. the teeth (n=12) were bonded with resin cement and endodontically treated. Thereafter, the access cavities were sealed with dual-cured composite resin. In composite resin core-post group (n=12), the teeth were endodontically treated and access cavities were sealed with dual-cured composite resin. In addition, the fractured segments in this group were fixed using horizontal posts. In composite resin core group (n=12), the teeth were endodontically treated and the access cavities were filled with dual-cured composite resin without horizontal posts. In bonded amalgam group (n = 12), the teeth were endodontically treated and the access cavities were sealed with bonded amalgam. Experimental complete crown-root fractures were induced again on repaired control and experimental teeth. The ratio of fracture resistance to original fracture resistance was analyzed with Kruskal-Wallis test. The results showed that teeth in control and composite resin core-post group showed significantly higher resistance to re-fracture than those in amalgam core group (p < 0.05). The resistance to refracture was high in the order of composite resin - post group, control group, composite resin group and bonded amalgam group. Within the scope of this study, the use of horizontal post could be beneficial in increasing the fracture resistance of previously fractured teeth.

• Management & Information Systems Review
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• v.32 no.3
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• pp.153-172
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• 2013

Small and medium-sized enterprises(SMEs) have limited human and material resources than large firms. SMEs are characterized by high risk and dynamic working environments. Thus human resources having knowledge and technologies are very important factor for survival and performance in SMEs. Recently, as core employee group is a key asset to firm competitiveness, many SMEs attend to set up core employee policy and system. The purposes of this research are to examine the effect of core employee policy and core employee management system on competitiveness of human resource and organizational commitment in SMEs. The major findings of the research are core employee policy have non-significant influence core employee management system, core employee policy have positive influence competitiveness of human resource, core employee management system have non-significant influence competitiveness of human resource, and competitiveness of human resource have positive influence organizational commitment in SMEs.

• Korean journal of communication and information
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• v.81
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• pp.299-328
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• 2017

This study investigated news comprehension via the social media by comparing the reading of a news story on the news paper. A news story on the social media was suggested to present information in a conversational form, which differs from a traditional reporting style. To compare the different forms of news information presentation, two conditions were created: in a control condition, a news story was written in a traditional reporting form. In the experimental condition, the same news story was constructed in a conversational form. Participants were assigned randomly in one of two conditions. They read the news story and afterwards, they were asked to recall firstly, the core idea of the news story, secondly the whole news story, and finally to answer to the 10 questions that assessed how well they learned from the news story. Participants' responses were content-analyzed and produced six variables, the extent to recall the core idea, the extent to recall the whole story, the extent to recall wrong information, the extent to recall additional information, the extent to recall causally related contents in general, and finally the extent to recall causally related contents in story-specific. Analyses on the six variables revealed that the group in the news paper condition recalled more core idea, the whole story, and additional information than the group in the social media. But the news paper condition recalled less of wrong information than the group in the social media condition. Additionally, the news paper condition learned more than the group in the social media. Regarding the recall of causally related contents, the general causal relationships were recalled more in the group in the social media condition but the story specific causal relationships were recalled more in the group in the news paper condition. The findings seemingly indicated that a traditional news reporting contributes to news story comprehension more than the conversational form. Authors however added discussions and advised that the findings needed to be read under caution.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.1
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• pp.22-30
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• 2008

Purpose: The purpose of this study is to compare three different CAD/CAM systems through the fracture strength of zirconia core and to evaluate the clinical availability of each system. Material and methods: The following three groups of 30 maxillary mesial incisor core for all-ceramics(each group 10) were fabricated as follows: group 1. $Adens^{(R)}$ CAD/CAM system, group 2. $Cerasys^{(R)}$ CAD/CAM system, group 3. 3M $Lava^{(R)}$ CAD/CAM system. All specimens were manufactured consistently thickness 0.5mm and relief $40{\mu}m$. Specimens were subjected to compressive loading on the lingual area by Z250/$SN5S^{(R)}$. Each group's mean and standard deviation were calculated and Kruskal Waillis test, Wilcoxon Rank Sum test were utilized to find out the relationship among the groups. Results: The results were as follows: 1. The mean fracture strength of $Adens^{(R)}$ system was $615.89{\pm}156.1N$, the $Cerasys^{(R)}$ system was $863.98{\pm}151.5N$, and the 3M $Lava^{(R)}$ system was $1143.1{\pm}286.6N$. 2. The fracture strength of the systems showed the significant statistical differences in order of 3M $Lava^{(R)}$ system, $Cerasys^{(R)}$ system, $Adens^{(R)}$ system. Conclusion: In this study, in spite of the differences among the groups, every group showed clinically useful results. It is necessary to study further clinical experiments on a long term basis.

• Journal of Powder Materials
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• v.26 no.6
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• pp.463-470
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• 2019

Fe₃O₄/SiO₂/YVO₄:Eu³⁺ multifunctional nanoparticles are successfully synthesized by facile stepwise sol-gel processes. The multifunctional nanoparticles show a spherical shape with narrow size distribution (approximately 40 nm) and the phosphor shells are well crystallized. The Eu³⁺ shows strong photoluminescence (red emission at 619 nm, absorbance at 290 nm) due to an effective energy transfer from the vanadate group to Eu. Core-shell structured multifunctional nanoparticles have superparamagnetic properties at 300 K. Furthermore, the core-shell nanoparticles have a quick response time for the external magnetic field. These results suggest that the photoluminescence and magnetic properties could be easily tuned by either varying the number of coating processes or changing the phosphor elements. The nanoparticles may have potential applications for appropriate fields such as laser systems, optical amplifiers, security systems, and drug delivery materials.