• The Journal of the Korean dental association
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• v.47 no.8
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• pp.479-486
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• 2009

Purpose: The aim of this study was to show the clinical results of combination of Nd-YAP (1340nm) laser therapy with conventional endodontic and periodontal treatment. Materials and Methods: Four patients with chronic advanced periodontitis and endodontic infection were treated with conventional treatment and Nd-YAP laser therapy. Occlusal adjustment and splinting were done for stabilization of the teeth with severe horizontal and vertical mobility. The protocol for periodontal treatment was followed as scaling and root planing, pocket irrigation with 3% $H_2O_2$ and exposure of Nd-YAP laser using 320${\mu}m$ optical fiber with 160mJ/pluse, 30Hz. The other protocol for endodontic treatment was followed as access opening, canal preparation by hand and rotary instrument, canal filling, and exposure of Nd-YAP laser using 200${\mu}m$ optical fiber with 200mJ/pluse, 10Hz and 180mJ/pluse, 5Hz which were used respectively for disinfection and canal filling. The assessments of probing depth, mobility, and radiography were made prior to and after treatment. Result: All of these four clinical cases showed good healing of periodontium, which presented decrease of mobility and pocket depth, and increase of bone regeneration and bone density on the radiography. Conclusion: The bactericidal effect of Nd-YAP laser would provide benefits for improving clinical results that are obtained from conventional therapy.

• Genomics & Informatics
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• v.10 no.2
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• pp.123-127
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• 2012

Gene set analysis (GSA) is useful in interpreting a genome-wide association study (GWAS) result in terms of biological mechanism. We compared the performance of two different GSA implementations that accept GWAS p-values of single nucleotide polymorphisms (SNPs) or gene-by-gene summaries thereof, GSA-SNP and i-GSEA4GWAS, under the same settings of inputs and parameters. GSA runs were made with two sets of p-values from a Korean type 2 diabetes mellitus GWAS study: 259,188 and 1,152,947 SNPs of the original and imputed genotype datasets, respectively. When Gene Ontology terms were used as gene sets, i-GSEA4GWAS produced 283 and 1,070 hits for the unimputed and imputed datasets, respectively. On the other hand, GSA-SNP reported 94 and 38 hits, respectively, for both datasets. Similar, but to a lesser degree, trends were observed with Kyoto Encyclopedia of Genes and Genomes (KEGG) gene sets as well. The huge number of hits by i-GSEA4GWAS for the imputed dataset was probably an artifact due to the scaling step in the algorithm. The decrease in hits by GSA-SNP for the imputed dataset may be due to the fact that it relies on Z-statistics, which is sensitive to variations in the background level of associations. Judicious evaluation of the GSA outcomes, perhaps based on multiple programs, is recommended.

• Journal of Periodontal and Implant Science
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• v.44 no.4
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• pp.169-177
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• 2014

Purpose: We aimed to investigate the impact of nonsurgical periodontal treatment combined with one-year dietary supplementation with omega (${\omega}$)-3 on the serum levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and arachidonic acid (AA). Methods: Fifteen patients with chronic generalized periodontitis were treated with scaling and root planing. The test group consisted of seven patients ($43.1{\pm}6.0$ years) supplemented with ${\omega}$-3, consisting of EPA plus DHA, three capsules, each of 300 mg of ${\omega}$-3 (180-mg EPA/120-mg DHA), for 12 months. The control group was composed of eight patients ($46.1{\pm}11.6$ years) that took a placebo capsule for 12 months. The periodontal examination and the serum levels of DPA, EPA, DHA, and AA were performed at baseline (T0), and 4 (T1), and 12 (T2) months after therapy. Results: In the test group, AA and DPA levels had been reduced significantly at T1 (P<0.05). AA and EPA levels had been increased significantly at T2 (P<0.05). The ${\Delta}EPA$ was significantly higher in the test compared to the placebo group at T2-T0 (P=0.02). The AA/EPA had decreased significantly at T1 and T2 relative to baseline (P<0.05). Conclusions: Nonsurgical periodontal treatment combined with ${\omega}$-3 supplementation significantly increased the EPA levels and decreased the AA/EPA ratio in serum after one year follow-up. However, no effect on the clinical outcome of periodontal therapy was observed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.2037-2047
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• 1991

Strength is not simply a single given value but rather is a statistical one with certain distribution functions. This is because it is affected by many unknown factors such as size, shape, stress distribution, and combined stresses. In this study, a model of loss probability is proposed in view of the fact that one of the fundamental configuration of nature is hexagonal, for example, the shapes of lattice unit, grain, and so on. The model sues the concept of loss of certain element in place of Jayatilaka-Trustrum's length and angle of cracks. Using this model, the loss probability due to each loss of certain elements is obtained. Then, the maximum principal stress is calculated by the finite element method at the centroid of the elements under the tensile load for the 4,095 models of analysis. Finally, the failure probability of the brittle materials is obtained by multiplying the loss probability by the ratio of the maximum principal stress to theoretical tensile strength. Comparison of the result of the Jayatilaka-Trustrum's model and the proposed model shows that the failure probabilities by the two methods are in good agreement. Further, it is shown that the parametric relationship of semi-crack lengths for various degrees of birittleness can be determined. Therefore, the analysis of the failure probability suing the proposed model is shown to be promising as a new method for the study of the failure probability of birttle materials.

• Journal of Korean society of Dental Hygiene
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• v.14 no.3
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• pp.363-370
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• 2014

Objectives : The purpose of the study is to investigate the effect of the oral hygiene care program in stroke patients. Methods : The subjects were 62 stroke patients of rehabilitation department in Youngnam University Hospital in Daegu. The study was carried out from January, 2010 to October, 2010. Intervention group was 35 and the control group was 31 patients. Tooth brushing instruction, oral health education and scaling were implemented in all patients at baseline. This program was conducted 5 times during hospitalization in intervention group. Results : In the intervention group, the mean age was 59.2 years, and women accounted for 66.7% and the control group consisted of 72.4% of women and mean age was 58.5 years. The average of the number of permanent teeth with experience of dental caries, the values of dental calculus index, plaque index, bleeding index and tooth mobility were 11.88, 11.79, 9.91, 3.16 and 1.16, respectively. The control group showed 10.21, 11.79, 9.91, 3.16 and 1.16, respectively. The proportion of subjects whose CPI was higher than 3 accounted for 97%, and the O'Leary index score was 38.6 in the intervention grou. The control group showed 100% and 38.79. Conclusions : Oral condition improved significantly in the intervention group in the third session. These findings may provide essential information for oral health program planning and implementation.

• Journal of Korean society of Dental Hygiene
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• v.19 no.6
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• pp.963-972
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• 2019

Objectives: This study analyzed the relationship between BMI (body mass index), perceived health status, and oral health behaviors of schoolgirls. Methods: This study utilized data from the 13th (2017) Korea Youth Risk Behavior Web-Based Survey. A total of 29,337 schoolgirls were analyzed. Statistical analysis was performed using PASW Statistics 21.0 (SPSS Inc., Chicago, IL, USA). Results: Compared to the obese group, the rate of being recognized as healthy was 1.882 times higher in the normal-weight group and 1.623 times in the underweight group. The rate of using supplementary oral hygiene devices was 1.383 times higher in the underweight group and 1.091 times in the normal-weight group than in the obese group. Compared to the obese group, the experience rate of the sealant was 1.407 times in the underweight group. Compared to the obese group, the scaling experience rate was 1.282 times higher for the underweight group and 1.205 times for the normal-weight group. Conclusions: These results suggest that individual health behaviors are interrelated. There is a need for an integrated approach in the planning and implementation of future health promotion strategies, and it would be useful to design a program that considers health characteristics such as BMI.

• The Journal of Internal Korean Medicine
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• v.41 no.5
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• pp.787-799
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• 2020

Objectives: Pityriasis rubra pilaris (PRP) is a rare papulosquamous disorder with unknown etiology. Studies on adults have not been conducted yet in Korean medicine. We report the progress of Korean medicine treatment for adult-type pityriasis rubra pilaris. Methods: A 62-year-old female patient was diagnosed with PRP in June 2019. After the diagnosis of PRP, retinoid treatment was continued for about 6 months, and then the drug was switched to an oral immunosuppressant. However, the patient's symptoms did not improve, but instead worsened. The patient was treated with Mihudeungsikjang-tang and acupuncture therapy. We evaluated her treatment progress based on the Dermatology Life Quality Index (DLQI), a visual analogue scale (VAS), and the changes in the patient's subjective symptoms. Results: After Korean medicine treatment, the DLQI and VAS scores improved from 18 points to 16 points and from 6 points to 4 points, respectively. The whole-body itching and scaling were reduced by 30% compared to pretreatment. The itching and pain in the neck, which had been severely symptomatic, decreased by 50%. The pain and dysesthesia in the upper and lower extremities disappeared, but the erythema still remained. Conclusions: Conventional treatments for PRP have limitations due to adverse effects and difficulty in treating refractory forms. Korean medicine treatment is worth considering as it can complement the limitations of conventional treatments, although more studies will be needed.

• International Journal of Highway Engineering
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• v.18 no.5
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• pp.21-29
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• 2016

PURPOSES : The purpose of this study is to suggest a specific investigation guideline to decide priority of repairing old concrete pavements that pile up substantially. METHODS : In this study, a principle of division of homogeneous sections was proposed to reflect the characteristics of the pavement reasonably in the specific investigation results. In addition, a checklist and guideline of field investigation were suggested for the old concrete pavement sections, which require inspection toward their durability and structural performance. Furthermore, the items of laboratory test necessary to the old concrete pavement were suggested based on the existing laboratory test considering characteristics of the old concrete pavement. The present condition of the old concrete pavement could be analyzed by the test results. RESULTS : A method of division of homogeneous sections suitable for the specific investigation of the old concrete pavement was suggested. The proportions of distress severity of pavement sections were compared by distress type to figure out the present state of the old concrete pavement. Scaling, durability cracking (or alkali-silica reaction), and longitudinal spalling were selected as the most severe distress types. The detailed positions of the sections were also suggested. The checklist of the specific investigation was categorized by field survey and laboratory test, and its evaluation criteria were proposed. The three types of the sections of durability cracking (or alkali-silica reaction), bridge connection, and asphalt overlay were selected as the sections of the field survey. The compressive strength, void structure, and chloride penetration depth were suggested as the items of the laboratory test. CONCLUSIONS : A fundamental level of the guideline was suggested in this study to resolve the problem of old concrete pavement. Appropriate guidelines related to the repair of the old concrete pavement should be provided by performing additional research efforts.

• Communications for Statistical Applications and Methods
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• v.17 no.4
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• pp.541-550
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• 2010

The $L_1$-regression estimator is susceptible to the leverage points, even though it is highly robust to the vertical outliers. This article is concerned with the improvement of robustness of the $L_1$-estimator. To improve its robustness, in terms of the breakdown point, we attempt to dampen the influence of the leverage points by means of reducing the weights corresponding to the leverage points. In addition the algorithm employs the linear scaling transformation technique, for higher computational efficiency with the large data sets, to solve the linear programming problem of $L_1$-estimation. Monte Carlo simulation results indicate that the proposed algorithm yields $L_1$-estimates which are robust to the leverage points as well as the vertical outliers.

• Journal of Korean society of Dental Hygiene
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• v.12 no.6
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• pp.1250-1259
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• 2012

Objectives : TThe purpose of this study was to examine the relationship between the oral health education experience of workers and their oral health awareness in an attempt to provide some information on corporate oral health education plans. Methods : The, subjects in this study were 230 workers in Busan and South Gyeongsang Province, on whom a self-administered survey was conducted from August, 2010, to June 18, 2011. A frequency analysis was carried out to grasp the general characteristics of the 205 respondents, and x2-test(p). Results : 1. As for the relationship of the oral health education experience of the workers and their awareness of toothbrush involving optimum toothbrush size, 47.4 percent of those without educational experience thought that a toothbrush should be large enough to cover about two teeth(p<.018). 2. Regarding the relationship between the oral health education experience of the workers and their awareness of fluoride, 59.1 percent of the respondents with educational experience perceived that dentifrice contained fluoride(p<.05). 3. Concerning the relationship between the oral health education experience of the workers and their awareness of periodontal diseases including the cause of the diseases, 43.6 percent of the respondents with educational experience(p<.021). 4. As to the relationship between the oral health education experience of the workers and their awareness of scaling, 50.2 percent of the respondents with educational experience and gingival diseases(p<.037). 5. In terms of the relationship between the oral health education experience of the workers and their awareness of toothbrushing involving toothbrushing frequency, 36.8 percent of those without it considered it necessary to do toothbrushing three times a day(p<.045). Conclusions : The above-mentioned findings illustrated that there were differences among the workers in oral health awareness according to their oral health education experience. Therefore the development of systematic oral health education programs is required to promote the oral health of workers.