• Journal of Periodontal and Implant Science
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• v.48 no.1
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• pp.3-11
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• 2018

Purpose: This study utilized a strong quasi-experimental design to test the hypothesis that the implementation of a policy to expand dental care services resulted in an increase in the usage of dental outpatient services. Methods: A total of 45,650,000 subjects with diagnoses of gingivitis or advanced periodontitis who received dental scaling were selected and examined, utilizing National Health Insurance claims data from July 2010 through November 2015. We performed a segmented regression analysis of the interrupted time-series to analyze the time-series trend in dental costs before and after the policy implementation, and assessed immediate changes in dental costs. Results: After the policy change was implemented, a statistically significant 18% increase occurred in the observed total dental cost per patient, after adjustment for age, sex, and residence area. In addition, the dental costs of outpatient gingivitis treatment increased immediately by almost 47%, compared with a 15% increase in treatment costs for advanced periodontitis outpatients. This policy effect appears to be sustainable. Conclusions: The introduction of the new policy positively impacted the immediate and long-term outpatient utilization of dental scaling treatment in South Korea. While the policy was intended to entice patients to prevent periodontal disease, thus benefiting the insurance system, our results showed that the policy also increased treatment accessibility for potential periodontal disease patients and may improve long-term periodontal health in the South Korean population.

• Journal of Periodontal and Implant Science
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• v.39 no.1
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• pp.37-44
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• 2009

Purpose: Tetracycline and its chemically modified non-antibacterial analogues can inhibit certain host-derived tissue destructive collagenases such as matrix metalloproteinases. The purpose of this study was to evaluate clinical and microbiologic effects of the subantimicrobial dose of doxycycline(SDD) in conjunction with scaling and root planing. Materials and methods: A total of 30 patients with chronic periodontitis who were going to receive scaling and root planing were randomly allocated to receive either a doxycycline hyclate for 3 months or nothing. Clinical probing depth, clinical attachment level, gingival recession, and bleeding on probing were measured by one periodontist. After a periodontal examination, microbial samples were collected using sterile paper points. The effect of SDD in conjunction with scaling and root planing on alterations of the periodontal pathogens (Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Porphyromonas gingivalis) were also assessed using l6S rRNA polymerase chain reaction. Results: During the treatment period, clinical parameters for both treatment group and control group were improved. After 3 months, reductions in probing depth and gains in clinical attachment level were significantly greater for the SDD group than control group. Microbial analysis showed that there was no alteration of the periodontal pathogens and no difference between the groups. Conclusion: This study suggested that the subantimicrobial dose of doxycycline as an adjunct therapy with scaling and root planing might be effective and safe in the management of chronic periodontitis.

• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.51-56
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• 2011

This study was conducted to investigate the applicability of pulsed electric field (PEF) treatment for the prevention of scaling formation and membrane fouling reduction. To validate the effect of PEF and to identify the mechanism, some experiments with and without PEF treatment were carried out. PEF treatment affected the precipitation of $CaCO_3$ by which $CaCO_3$ particles were actively grown and sedimented. It was confirmed that the calcium ions were decreased as 78% and particle size was grown by PEF treatment. It was also verified that the crystalline structure of $CaCO_3$ was transformed by PEF treatment from Aragonite, which is formed at a high temperature and hard to be removed, to Calcite being stable at room temperature. In PEF treatment, permeate volume and permeation flux were greater than that of without PEF, case while Langelier Index(LI) decreased. From the experiment results, PEF treatment is believed to be an effective method to prevent scaling formation and to mitigate $CaCO_3$ fouling as the pretreatment of membrane filtration.

• Tunnel and Underground Space
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• v.15 no.1 s.54
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• pp.55-60
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• 2005

In this study, the 1/20 reduced-scale experiments using Froude scaling were conducted to investigate the effect of longitudinal ventilation on the variation of burning rate in tunnel fires. The methanol square pool fires with heat release rate ranging from 3.57 kW to 10.95 kW were used. The burning rate of fuel was obtained by measured mass using load cell and temperature distribution were measured by K-type theomocouples in order to investigate smoke movement. The wind tunnel was connected with one side of the tested tunnel, and logitudinal ventilation velocity in the tested tunnel was controlled by power of the wind tunnel. In methanol fire case, the increase in ventilation velocity decreased the turning rate due to the direct cooling of fire plume. For the same dimensionless velocity(V), homing rate decreased as the size of pool fire increased.

• Progress in Superconductivity
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• v.7 no.2
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• pp.103-108
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• 2006

We have measured the Hall resistivity (${\rho}_{xy}$) and the longitudinal resistivity (${\rho}_{xy}$) on superconducting $MgB_2$ thin films in extended fields up to 18 T. We found a universal scaling behavior between the Hall resistivity and the longitudinal resistivity, which is independent of the temperature and the magnetic field. At a wide magnetic field region from 1 to 18T, a universal power law of ${\beta}=2.0{\pm}0.1$ in a scaling relation, ${\rho}_{xy}={A{\rho}_{xx}}^{\beta}$, was observed in c-axis-oriented $MgB_2$ thin films. These results can be well interpreted by using recent models.

• Journal of Korean society of Dental Hygiene
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• v.13 no.3
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• pp.387-393
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• 2013

Objectives : This study was carried out to investigate stepwise regression analysis on cervical abrasion & general characteristics, subjective oral health perception, habit related to oral health, and oral symptom. Methods : The study subjects were 2,158 workers in 23 industrial work places located in Gumi-si, Gyeongsangbuk-do Province from June 1 to July 1, 2012. As a result, the following conclusions were obtained. Results : 1. The cervical abrasion rate was high in men and older age group. 2. The cervical abrasion rate was high in a case of having not received scaling for the past one year. 3. The cervical abrasion rate was high in frequent tooth brushing. 4. The cervical abrasion rate was high in group having no bleeding in tooth and the gum. 5. The cervical abrasion rate was high in group having the cold symptom in teeth. 6. Excluding gum pain and bleeding, factors affecting tooth abrasion were gender, age, scaling over the past year, frequency of brushing a day and tooth sensitivity when cold food was ingested. 7. Gender and tooth sensitivity turned out to have negative(-) effect. age, scaling over the past year and frequency of brushing a day turned out to have positive(+) effect. Conclusions : Through this study, the best prevention method of cervical abrason is effective tooth brushing education and regular dental check up.

• The Bulletin of The Korean Astronomical Society
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• v.33 no.1
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• pp.27.2-27.2
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• 2008

• 한국초전도학회:학술대회논문집
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• 2008.08a
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• pp.62-62
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• 2008

• Journal of Environmental Science International
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• v.29 no.1
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• pp.15-23
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• 2020

The determination of soil characteristics is important in the simulation of rainfall runoff using a distributed FLO-2D model in catchment analysis. Digital maps acquired using remote sensing techniques have been widely used in modern hydrology. However, the determination of a representative parameter with spatial scaling mismatch is difficult. In this investigation, the FLO-2D rainfall-runoff model is utilized in the Yongdam catchment to test sensitivity based on three different methods (mosaic, arithmetic, and predominant) that describe soil surface characteristics in real systems. The results show that the mosaic method is costly, but provides a reasonably realistic description and exhibits superior performance compared to other methods in terms of both the amount and time to peak flow.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.480-484
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• 2000

The channel length influence of n-channel Si-based FETs is investigated by computer simulation. Using a two-dimensional hydrodynamic model, devices having various gate length are examined. We have observed the characteristics of LDD model of MOSFET by investigating of their current, voltage, electric field and impact ionization. These devices are scaled using various factors. We have analyzed I-V characteristics and the effect of impact ionization according to channel length.