• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.374-380
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• 2018

PURPOSE. The effect of silica-based glass-ceramic liners on the tensile bond strength between zirconia and resin-based luting agent was evaluated and compared with the effect of 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing primers. MATERIALS AND METHODS. Titanium abutments and zirconia crowns (n = 60) were fabricated, and the adhesive surfaces of the specimens were treated by airborne-particle abrasion. The specimens were divided into 5 groups based on surface treatment: a control group, 2 primer groups (MP: Monobond Plus; ZP: Z Prime Plus), and 2 liner groups (PL: P-containing Liner; PFL: P-free Liner). All specimens were cemented with self-adhesive resin-based luting agent. After 24-hour water storage and thermocycling (5,000 cycles, $5^{\circ}C/55^{\circ}C$), the tensile bond strength was measured using a universal testing machine. Failure mode analysis and elemental analysis on the bonding interface were performed. The data were analyzed using Kruskal-Wallis test, Dunn's post hoc test, and Fisher's exact test. RESULTS. The liner groups and primer groups showed significantly higher tensile bond strengths than that of the control group (P<.05). PFL showed a significantly higher tensile bond strength than the primer groups (P<.05). The percentage of mixed failure was higher in the primer groups than in the control group (P<.001), and all the specimens showed mixed failure in the liner groups (P<.001). A chemical reaction area was observed at the bonding interface between zirconia and liner. CONCLUSION. The application of liner significantly increased the tensile bond strength between zirconia and resin-based luting agent. PFL was more effective than MDP-containing primers in improving the tensile bond strength with the resin-based luting agent.

• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.177-183
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• 2018

PURPOSE. The purpose of the current study was to evaluate the effect of incorporating nanoparticles of silver (NAg) and amorphous calcium phosphate (NACP) into a self-etching primer of a resin cement on the microtensile bond strength of dentin, regarding the proven antibacterial feature of NAg and remineralizing effect of NACP. MATERIALS AND METHODS. Flat, mid-coronal dentin from 20 intact extracted human third molars were prepared for cementation using Panavia F2.0 cement. The teeth were randomly divided into the four test groups (n=5) according to the experimental cement primer composition: cement primer without change (control group), primer with 1% (wt) of NACP, primer with 1% (wt) of physical mixture of NACP+Nag, and primer with 1% (wt) of chemical mixture of NACP+Nag. The resin cement was used according to the manufacturer's instructions. After storage in distilled water at $37^{\circ}C$ for 24 h, the bonded samples were sectioned longitudinally to produce $1.0{\times}1.0mm$ beams for micro-tensile bond strength testing in a universal testing machine. Failure modes at the dentin-resin interface were observed using a stereomicroscope. The data were analyzed by one-way ANOVA and Tukey's post-hoc tests and the level of significance was set at 0.05. RESULTS. The lowest mean microtensile bond strength was obtained for the NACP group. Tukey's test showed that the bond strength of the control group was significantly higher than those of the other experimental groups, except for group 4 (chemical mixture of NACP and NAg; P=.67). CONCLUSION. Novel chemical incorporation of NAg-NACP into the self-etching primer of resin cement does not compromise the dentin bond strength.

• Korean Journal of Community Nutrition
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• v.29 no.4
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• pp.278-287
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• 2024

Objectives: This study investigates the relationship between smartphone usage and eating behavior among elementary school students. Methods: This survey was conducted on 4th- to 6th-grade students at elementary schools in Gangneung from September 6th to September 15th, 2023. Of the 129 copies of the questionnaire that were distributed to 5 schools, 66 copies (51.2%) were returned. Results: Compared to the nationwide statistics, the smartphone ownership rate of elementary school students in Gangneung was lower, but the rate of smartphone overdependence was higher. Smartphone dependence was 21.12 points for study subjects and 26.00 points for the overdependence risk group (Org). Compared to national statistics, the self-control failure factor was higher, so study participants in Gangneung City are thought to have great difficulty with self-control. The Org's weekend smartphone use time of 7.54 hours was significantly more than the general user group (Gug)'s 4.06 hours. The number of days in which the Org consumed late-night snacks per week was 2.92 days, and the Gug had 2.15 days, but the difference was not significant. Eating fast food showed a positive correlation with eating sweet food, eating fatty food, and eating heavily seasoned food. It was found that frequent consumption of fast food is closely correlated with unhealthy eating behavior. Weekend smartphone use time showed a significant positive correlation with smartphone dependence and the number of days late-night snacks consumed per week. Conclusions: Study participants in Gangneung are more dependent on smartphones than national statistics. Smartphone dependence had a negative correlation with healthy eating behavior and a correlation with average unhealthy eating behavior.

• Clinical and Experimental Pediatrics
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• v.64 no.6
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• pp.251-259
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• 2021

Psychogenic nonepileptic seizures (PNES) is a neuropsychiatric condition that causes a transient alteration of consciousness and loss of self-control. PNES, which occur in vulnerable individuals who often have experienced trauma and are precipitated by overwhelming circumstances, are a body's expression of a distressed mind, a cry for help. PNES are misunderstood, mistreated, under-recognized, and underdiagnosed. The mind-body dichotomy, an artificial divide between physical and mental health and brain disorders into neurology and psychiatry, contributes to undue delays in the diagnosis and treatment of PNES. One of the major barriers in the effective diagnosis and treatment of PNES is the dissonance caused by different illness perceptions between patients and providers. While patients are bewildered by their experiences of disabling attacks beyond their control or comprehension, providers consider PNES trivial because they are not epileptic seizures and are caused by psychological stress. The belief that patients with PNES are feigning or controlling their symptoms leads to negative attitudes of healthcare providers, which in turn lead to a failure to provide the support and respect that patients with PNES so desperately need and deserve. A biopsychosocial perspective and better understanding of the neurobiology of PNES may help bridge this great divide between brain and behavior and improve our interaction with patients, thereby improving prognosis. Knowledge of dysregulated stress hormones, autonomic nervous system dysfunction, and altered brain connectivity in PNES will better prepare providers to communicate with patients how intangible emotional stressors could cause tangible involuntary movements and altered awareness.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.1
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• pp.41-46
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• 2024

The current study investigates the seismic performance of shear-dominant RC columns retrofitted with iron-based shape memory alloy (Fe SMA). Three RC columns with insufficient transverse reinforcement were designed and fabricated for lateral cyclic loading tests. Before testing, two specimens were externally confined with carbon fiber-reinforced polymer (CFRP) sheets and self-prestressed Fe SMA strips. The test results showed that both CFRP and Fe SMA performed well in preventing severe shear failure exhibited by the unretrofitted control specimen. Furthermore, the two retrofitted specimens showed ductile flexural responses up to the drift ratios of ±8%. In terms of damage control, however, the Fe SMA confinement was superior to CFRP confinement in that the spalling of concrete was much less and that the rupture of confinement did not occur.

• Journal of the Korean School Mathematics Society
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• v.2 no.1
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• pp.15-30
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• 1999

For the purpose of turning learners' locus of control into internal-controllable variables, counseling materials were developed, and attribution counseling was given. The counseling effects were practically confirmed by way of teaching and evaluation in the actual classes, and furthermore the efforts to provide learners with successful experiences in learning were repeatedly made. As a result, the conclusions are as follows: 1. The procedure of Individual counseling for learning attribution based on individual standard grades and data of the variable order of merit apparently shows learners that if learners are to try their best in learning, they will surely go far in terms of learning in the near future. 2. The procedure of Individual counseling for teaming attribution based on achievement distribution in individual behavior-oriented fields suggests to learners that how to learn is as important as how much effort they make. Surely enough, learners are required to make more effective and efficient efforts, considering their own learning abilities. 3. With the above 1, 2 procedures involved, learners have attributed locus of causality in achievement to their internal-controllable causes. 4. With preparatory assignments according to learner's abilities provided, even slower learners came to be assured that their constant efforts could give rise to success in learning achievement. 5. Above all, it was confirmed that the learners' struggling attitude might well have a significant correlation with achievement success. The learners who are willing to attribute locus of causality in achievement to their internal-controllable causes or strenuous efforts and intrinsic motivation tend to be convinced that they can address themselves to whatever faces them, so they can set up specific learning goals fit for their abilities. Accordingly, they will bit by bit acquire successful experiences (often called 'Aha' experiences) and in turn, feeling the senses of self-efficacy and self-esteem enough to push their efforts even further, they can grow to form a positive self-concept. With one successful experience after another fed back into learners, they are gradually motivated to bring the oncoming achievement expectation to a higher level. To conclude, it is necessary that instruction leading to internal-controllable attribution should be provided, inducing learners to recognize success and failure in learning achievement as a result of their strenuous efforts.

• Informatization Policy
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• v.23 no.2
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• pp.3-18
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• 2016

Radical paradigm shift is being expected due to the coming of the so-called intelligent society. In the intelligent society, things or machines are able to use intelligence for the first time in history and this will bring about fundamental changes at every corner of human society. This article analyzes views of the world in order to figure out basic directions of this paradigm shift. A dualistic view of world mediated by technology is suggested for a new world view of the intelligent society, based on comparison of a traditional dualistic view of world between human-nature and a tripartite view of world between human-machine-nature. This article summarizes paradigms of the intelligent society into four ; externalization of intelligence, productivity explosion, platform society, and self-organizing society. These new paradigms will provide lots of benefits such as intelligence augmentation, production capacity increase, and self-organizing effect. But at the same time, it will increase risks of system failure because of loss of human control on technologies. In conclusion, it is argued that human choices and efforts will decide the future of the intelligent society becuase the paradigm shift is value neutral in essence.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.239-251
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• 2012

This study aims to seek the policies and the plans for the successful small business start-up through an exploratory study about the factors affecting the success rate of small business start-up. To measure the performance of the start-up business(sales revenue, net profit, and outcome expectancy), the characteristics of founders (experience, psychological characteristics) and the preparation of small business start-up were measured as independent variables and the self-efficacy was measured as a parameter. 427 small business owners were targeted and structured self-administered questionnaires were collected from them. For the data process, a multiple regression analysis by SPSS 18.0 was conducted. The findings demonstrated the experience in the same business, the need for achievement, the risk-taking propensity, the preparation period for business start-up had a significant effect on self-efficacy, and experience of failure and the ratio of net worth had a significant effect on sales revenue and net profit, and the locus of control had a significant effect on outcome expectancy through the self-efficacy, a parameter. It was also noted the self-efficacy of small business owners and the business performance varied depending on the characteristics of them and the preparation process of the business start-up. Based on the those findings, the theoretical and practical implications were discussed and the suggestions about the limits of the study, future policies and studies were made.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.253-275
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• 1994

Many flowering plants possess genetically controlled self -incompatibility (SI) system that prevents inbreeding and promotes outcrosses. SI is usually controlled by a single, multiallelic S-locus. In gametophytically controlled system, SI results when the S-allele of the pollen is matched by one of the two S-alleles in the style, while in the sporophytic system self-incompatible reaction occurs by the interaction between the pistil genotype and genotype of, not the pollen, but the pollen parent In the former system the self-incompatible phenotype of pollen is determined by the haploid genome of the pollen itself but in the latter the pollen phenotype is governed by the genotype of the pollen parent along with the occurrence of either to-dominant or dominant/recessive allelic interactions. In the sporophytic type the inhibition reaction occurs within minutes following pollen-stigma contact, the incompatible pollen grains usually failing to germinate, whereas in gametophytic system pollen tube inhibition takes place during growth in the transmitting tissue of the style. Recognition and rejection of self pollen are the result of interaction between the S-locus protein in the pistil and the pollen protein. In the gametophytic SI the S-associated glycoprotein which is similar to the fungal ribonuclease in structure and function are localized at the intercellular matrix in the transmitting tissue of the style, with the highest concentration in the collar of the stigma, while in the sporophytic SI deposit of abundant S-locus specific glycoprotein (SLSG).is detected in the cell wall of stigmatic papillae of the open flowers. In the gametophytic system S-gene is expressed mostly at the stigmatic collar the upper third of the style length and in the pollen after meiosis. On the other hand, in the sporophytic SI S-glycoprotein gene is expressed in the papillar cells of the stigma as well as in e sporophytic tape is cells of anther wall. Recognition and rejection of self pollen in the gametophytic type is the reaction between the ribonuclease in the transmitting tissue of the style and the protein in the cytoplasm of pollen tube, whereas in the sporophytic system the inhibition of selfed pollen is caused by the interaction between the Sycoprotein in the wall of stigmatic papillar cell and the tapetum-origin protein deposited on the outer wall of the pollen grain. The claim that the S-allele-associated proteins are involved in recognition and rejection of self pollen has been made merely based on indirect evidence. Recently it has been verified that inhibition of synthesis of S$_3$ protein in Petunia inflata plants of S$_2$S$_3$ genotype by the antisense S$_3$ gene resulted in failure of the transgenic plant to reject S$_3$ pollen and that expression of the transgenic encoding S$_3$ protein in the S$_1$S$_2$ genotype confers on the transgenic plant the ability to reject S$_3$ pollen. These finding Provide direct evidence that S-proteins control the s elf-incompatibility behavior of the pistil.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.4
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• pp.419-426
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• 2017

Attachment of the orthodontic bracket conducted during the window opening procedure can result in failure due to various adverse conditions such as blood or saliva contamination, or other wet conditions. For the success of the bracket attachment, reduction of total operation time is crucial. The purpose of this literature is to evaluate the differences between the final resultant shear bond strength of the conventional method of using phosphoric acid and self-etching primer, and that of the operation time-reduced method in which the curing step is omitted subsequent to the primer application. A total of 40 human maxillary incisors were prepared. Group I(control group) and II were etched with 37% phosphoric acid and Group III and IV were conditioned with self-etching primer. Attachment of the group I and III was conducted by manufacturer's instructions. The operation time of Group II and IV was reduced by eliminating the curing step after the primer application. The resultant shear bond strength of each group was measured and an adhesive remnant index (ARI) was recorded. The mean shear bond strength of group I, II, III, and IV were 14.16 MPa, 8.33 MPa, 8.29 MPa, and 6.48 MPa respectively. Significant differences could only be found between the control group and the experimental groups (p < 0.05). The ARI indicated no significant difference among all groups.