• World Technopolis Review
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• 제8권1호
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• pp.2-7
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• 2019

If China can emerge from its current recession and complete its ongoing transition to technology-leader status, it will be an ever more dominant force in Asia and worldwide. Years spent living in Asia have spurred the co-Editor-in-Chief of this journal to offer informal comments on the status and prospects of China's socio-technical situation.

• The Journal of Korean Academy of Prosthodontics
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• 제55권3호
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• pp.325-330
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• 2017

In the case of single tooth replacement, a fixed prosthesis or a dental implant is the treatment option commonly selected as first choice. However, any amount of sound tooth structure should be removed to prepare the abutment teeth for full coverage retainer. The adjacent tooth damage can be avoided placing a dental implant. However, depending on the patient's oral condition and any other circumstances, it may be impossible or delayed. In this case resin bonded fixed partial denture was selected as an alternative that can restore single tooth loss without much tooth structure removal to the young patients and the patients with gingival recession. We report these patients were satisfied with esthetic and function.

• Current Industrial and Technological Trends in Aerospace
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• 제8권1호
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• pp.12-22
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• 2010

The great recession which caused by financial crisis made steep rise of oil price and the serious problems of the aircraft industry. High oil price increases operating cost and the recession decreases air traffic. After a period of high book order and delivery from global economic recovery, the aircraft order fell down suddenly. Also the Aircraft price and lease rate deceased and the MRO market is reduced, too. But, the air cargo and passenger increase again since late of 2009. So, it is difficult to predict the market movement, most of the forecasters agreed that the air traffic and aircraft demand will grow gradually in long term with the growth of emerging markets like China, India and Africa. And more efficient, safe and clean aircraft is needed and will need in the market.

• Current Industrial and Technological Trends in Aerospace
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• 제8권1호
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• pp.3-11
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• 2010

Despite the global economic recession, the space market has reached a historical peak of $160.9 billion in 2009, a 11 % growth compared to the previous year. The world governments' investments on space programs totaled $68 billion in 2009, 11% growth compared to 2008. However, Korea invested $217 million in 2009, 24% decrease compared to 2008. The completion of the 'Naro' rocket project has an impact regard to the budget cut. The Korean space market decreased 3% to $789 million due to the decrease of the export of satellite phone by economic recession. In this paper the current statuses of world governments' funding for space program and space market were presented and the current issues on the Korean space budget policy were reviewed.

• Journal of Periodontal and Implant Science
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• 제25권3호
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• pp.459-469
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• 1995

The objectives of this study were to examine the prevalence of gingival recession (GR)and cervical abrasion(CA) and to relate some considered factors to them. We selected 308 subjects, consisting of male 174 and female 134, who had 14 teeth at least. As age increased, the prevalence rates of GR & CA was increased. And both the rates of GR & CA were higher in male than in female. Interestingly, the effect of alcohol consumption was the highest in GR and smoking affected CA highly among several variables. However, we could not prove the direct relationship between drinking & smoking and GR & CA. Only we assumed poor oral hygiene due to drinking & smoking as one of predisposing factors. The result of this study did not show the obvious factor which affected GR and CA greatly. The present study suggested that GR & CA should be related to a number of factors.

• Journal of Distribution Science
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• 제12권5호
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• pp.61-69
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• 2014

Purpose - Many studies report that returns on hedge portfolios that eliminate particular risk types are abnormal from traditional asset pricing models' perspectives. This study examines the pervasiveness of anomalous returns conditioned on business cycle and group size. Research design, data, and methodology - Using KOSPI and KOSDAQ market data from July 1991 to December 2013, we categorize stocks into appropriately sized groups, and dichotomize our sample periods into expansion and recession periods then, we construct hedge portfolios by sorting stocks by anomaly variables and calculate their returns. Results - Four anomalies, including earnings yield, net stock issue, total asset growth, and liquidity appear pervasive across all groups for the entire sample period. However, only the hedge returns of net stock issues are significant across all group sizes during both expansion and recession. Conclusions - A net stock issue can be an appropriate proxy for expected growth of book equity for all group sizes in recessions. This finding could provide insights to investment industry participants and to researchers interested in the relationship between expected growth of book equity and business cycle risk.

• Journal of Periodontal and Implant Science
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• 제41권3호
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• pp.143-148
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• 2011

Purpose: Few epidemiologic studies have investigated aggressive periodontitis in Koreans, but such studies of disease prevalence and other clinical characteristics would be invaluable in providing proper treatment. The aim of this study was to assess the prevalence of aggressive periodontitis and to measure the extent of associated periodontal breakdown. Methods: The study population consisted of 1,692 patients who visited the Department of Periodontology, Wonkwang Daejeon Dental Hospital from January to December, 2010. Clinical parameters (probing depth, gingival recession, periodontal attachment loss) were measured by a single examiner, and radiographic examination was performed at the baseline. Results: Twenty-eight (1.65%) patients showed clinical features of aggressive periodontitis, of which 27 patients exhibited the generalized form, and 1 exhibited the localized form. There was no significant difference between the percentage of male and female patients. The probing pocket depth of the maxillary first molar was deeper than that of the other teeth and gingival recession was also the most serious at the maxillary first molar. The periodontal attachment loss was the highest at the maxillary first molar. The average number of missing teeth was 1.29 per subject. Loss of the second molar was prominent. Conclusions: Within the limitations of this study, the periodontal breakdown evaluated by attachment loss was found to be most severe at the first molars of aggressive periodontitis patients. However, further large scale multicenter studies are necessary to access more precise data, including prevalence.

• The korean journal of orthodontics
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• 제44권4호
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• pp.217-225
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• 2014

Single-tooth implantation has become a common treatment solution for replacement of a root-fractured maxillary incisor in adults, but the long-term esthetic results can be unfavorable due to progressive marginal bone loss, resulting in gingival recession. In this case report, a maxillary central incisor with a root fracture in its apical one-third was orthodontically extruded and extracted in a 21-year-old female. Implant surgery was performed after a 3-month healing period, and the final crown was placed about 12 months after extraction. After 12 years, favorable osseous and gingival architectures were visible with adequate bone height and thickness at the buccal cortical plate, and no gingival recession was seen around the implant-supported crown. Although modern dentistry has been shifting toward simplified, clinical procedures and shorter treatment times, both general dentists and orthodontists should be aware of the possible long-term esthetic advantages of orthodontic extrusion of hopelessly fractured teeth for highly esthetically demanding areas and should educate and motivate patients regarding the choice of this treatment solution, if necessary.

• Journal of Periodontal and Implant Science
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• 제28권3호
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• pp.507-517
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• 1998

This study was performed to investigate the soft tissue changes around single implant-supported crowns during followup periods. Twenty patients(31 implants) whose single missing tooth in the maxillary anterior region had been replaced with an single implant-supported crown were recruited for the study. Crown length, soft tissue level and papilla height at the single implant-supported crowns were measured at follow-up examination and calculated from the slides taken at time of crown placement. as well Papilla index was scored from the slides taken at the time of crown placement and follow-up examination. A very little amount of recession occurred and the soft tissue level moved more apically and the papilla height increased significantly (p<0.01). Especially, both mesial and distal papilla index at single implant-supported crowns increased significantly during follow-up periods (p<0.001). When the two slides taken at the time of crown placement and follow-up were compared simultaneously, except one site, papillae size increased at all sites. From the results of the study, the interdental papillae at the single implant-supported crowns seemed to regenerate significantly and their crown margins were stable during follow-up periods. Hence it is indicated that various surgical interventions at on early stage to enhance soft tissue esthetics arourd single implants may be unnecessary.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.179-187
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• 2000

The objectives of this study were to measure keratinized gingival thickness in healthy Korean adults, and to correlate the keratinized gingival thickness with width of keratinized gingiva, probing pocket depth and gingival recession.Thickness measurements were performed in 37 Korean dental students using an ultrasonic device(SDM). Width of keratinized gingiva, gingival recession and probing pocket depth were measured with a Williams periodontal probe.The results showed that the keratinized gingival thickness varied from 0.83 mm(canines) to 1.16 mm(central incisors) in the maxilla and, in the mandible, from 0.68 mm(1st premolars) to 1.69 mm(2nd molars). In a stepwise multiple linear regression analysis, 23% of variation of gingival thickness could be explained by width of keratinized gingiva and probing pocket depth. It could be concluded that the keratinized gingival thickness depends on tooth type and correlates with width of keratinized gingiva and probing pocket depth.