• Journal of dental hygiene science
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• v.6 no.2
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• pp.101-105
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• 2006

To conduct this study, researchers personally visited two maternity hospitals, one public centers, and two gymnastics classes for pregnant women in some areas of Seoul from March 14 to April 28, 2005 to determine a simplified oral hygiene index to measure cleanness for 200 women in the twenty weeks and over of pregnancy in order to examine their oral health conditions and provide basic data for the future oral health care and education in oral hygiene for pregnant women and, consequently, drew the following conclusions. 1. Simplified oral hygiene index between early, middle, and late pregnancy. It was shown that the Early was $1.10{\pm}.91$, Middle was $1.78{\pm}1.02$, The simplified oral hygiene index of Late was $1.73{\pm}1.03$. The simplified oral hygiene index of Total was $1.47{\pm}1.03$, with a Food debris index $0.96{\pm}0.51$ and a Calculus score $0.51{\pm}0.52$. 2. There were statistically significant differences in the simplified oral hygiene index of both the upper and the lower jaws between early, middle, and late pregnancy (p < 0.01). It was shown that the Food debris index, Calculus score, and the simplified oral hygiene index all increased with the approach of delivery. 3. There were statistically significant differences in the simplified oral hygiene index of both the anterior and the posterior areas between early, middle, and late pregnancy (p < 0.01). It was found that the Food debris index, Calculus score, and the simplified oral hygiene index all increased with the approach of delivery.

• Structural Engineering and Mechanics
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• v.75 no.3
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• pp.377-387
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• 2020

Modern long-span floor system typically possesses low damping and low natural frequency, presenting a potential vibration sensitivity problem induced by human activities. Field test and numerical analysis methods are available to study this kind of problems, but would be inconvenient for design engineers. This paper proposes a simplified method to determine the acceleration amplitudes of long-span floor system subjected to walking or running load, which can be carried out manually. To theoretically analyze the acceleration response, the floor system is simplified as an anisotropic rectangular plate and the mode decomposition method is used. To facilitate the calculation of acceleration amplitude a_P, a coefficient α_wmn or α_Rmn is introduced, with the former depending on the geometry and support condition of floor system and the latter on the contact duration t_R and natural frequency. The proposed simplified method is easy for practical use and gives safe structural designs.

• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.1083-1093
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• 2010

Objective : The purpose of this study was to examine the relationship of the oral health behavior of oral prophylaxis clients and some residents in a community to their simplified oral environment index. Methods : The subjects in this study were 520 people who had their teeth cleaned in the oral prophylaxis practice lab in the department of dental hygiene at J health college. A survey was conducted from March 23 to June 3, 2010, by way of the self-reported questionnaire. The data materials are analyzed by general characteristics frequency and ratio, the relationship of oral health behavior and sex, age, scaling experience, simplified oral hygiene index $x^{2}$ test analysis. Results : 1. Concerning links between gender and oral health behavior including daily toothbrushing frequency, the largest group of the respondents brushed their teeth three times a day(p<0.05). As to educational experiences on toothbrushing method and the use of oral hygiene supplies, the women had more educational experiences than the men(p<0.05). 2. Regarding connections between age and oral health behavior involving daily toothbrushing frequency, the largest number of the respondents brushed their teeth three times a day in every age group (p <0.001). As for educational experiences on toothbrushing method, those who were in their 50s and up(64.7%) learned about that, and they had more educational experiences with age(p<0.05). As for scaling experiences, the older respondents had their teeth scaled more often (p<0.001). 3. As to relationship between scaling experiences and oral health behavior, there were differences in toothbrushing frequency according to scaling experiences(p <0.05). Regarding educational experiences on toothbrushing method, those who had their teeth cleaned received more toothbrushing education(p<0.001). Concerning smoking, the nonsmokers had more experiences to get their teeth cleaned (p<0.001). 4. As for links between simplified oral environment index and oral health behavior including a time for toothbrushing, the respondents who did toothbrushing after every meal(80.4%) had good simplified oral environment indexes(p<0.05). 5. In regard to relationship between simplified oral environment index and oral health behavior, oral environment index had a positive correlation to the use of oral hygiene supplies( r=0.129**), toothbrushing time(r=0.116**) and educational experiences on toothbrushing method (r=0.099**). Smoking(r=-0.092**) had a negative correlation to that. Conclusion : The above-mentioned findings illustrate that oral health behavior is one of crucial factors to affect oral health status and oral environment care. Therefore oral prophylaxis practice lab visitors should receive education on the right toothbrushing method and the use of oral hygiene supplies to promote their oral health, and an incremental oral health care system that involves regular scaling should be introduced.

• The Journal of the Korean dental association
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• v.53 no.5
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• pp.368-376
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• 2015

Purpose : The objective of this research was to develop a more simplified drilling procedure with an enhanced implant drill. Materials and Methods : The drill enhanced design factors enabled implantation of Dia. 5.0mm fixture with only 2 times drilling which is more simplified drilling procedure. The enhanced drill was designed with 2 flutes, 2-phase or 3-phase formed drill tip and 25 degrees of helix angle. The proposed drilling procedure (2 times) was compared with a general drilling process (4 times) in terms of temperature changes, cutting time and ISQ value. Results : The simplified drilling procedure indicated less heat than a conventional drilling procedure (p<0.05). The enhanced drill showed significantly shorter drilling time than a conventional drill (p<0.05). On the other hand, higher insertion torque and ISQ value were observed on the the suggested drilling procedure than the conventional drilling procedure (p<0.05). Conclusion : A simplified drilling procedure with the newly designed drill could provide higher effectiveness and safety of dental implant operations under properly controlled external conditions, such as irrigation and RPM of drilling.

• Structural Engineering and Mechanics
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• v.33 no.3
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• pp.387-390
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• 2009

• Journal of Periodontal and Implant Science
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• v.53 no.1
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• pp.85-95
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• 2023

Purpose: In recent years, guided implant surgery has been widely used for the convenience of patients and surgeons. Further streamlining the surgical procedure would make implant surgery more convenient. Low-speed water-free conditions are often used in guided implant surgery. Therefore, in this study, we attempted to confirm once again whether drilling was safe at a low speed without water. The main purpose of this study was to evaluate whether a simplified drilling protocol that omits some intermediate steps in the drilling process was safe from the viewpoint of heat generation. Methods: D1 density artificial bone blocks were drilled under 50 rpm, 10 N·cm water-free conditions, and the surface temperature was measured using a digital infrared camera. First, drilling was performed with the sequential drilling method, which is the most widely used technique. Second, for each drill diameter, the temperature change was measured while performing simplified drilling with omission of the previous 1, 2, or 3 steps. Results: In sequential drilling, the heat generated during drilling at all diameters was less than the critical temperature of osteonecrosis (47℃) except for the ⌀2 drill. Statistical significance was observed in all groups when comparing sequential and simplified drilling in the ⌀3.2, ⌀3.8, and ⌀4.3 drills (P<0.001). However, in the simplified drilling procedures, the temperature was below the osteonecrosis threshold temperature (47℃) except for the ⌀4.3 drill with the omission of the previous 3 steps (⌀3.0, ⌀3.2, and ⌀3.8). Conclusions: In general, drilling under low-speed, water-free conditions has shown stable results in terms of heat generation. Simplified drilling showed statistically significantly greater heat generation than sequential drilling. However, most of the diameters and omitted steps seem to be clinically acceptable, so it will be useful if an appropriate selection is made according to the patient's clinical condition.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.847-858
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• 2011

We make use of the simplified Hirota's bilinear method with computer symbolic computation to study a variety of coupled potential KdV (pKdV) equations. Each coupled equation is completely integrable and gives multiple soliton solutions and multiple singular soliton solutions. The phase shifts for all coupled pKdV equations are identical whereas the coefficients of the obtained solitons are not identical. The four coupled pKdV equations are resonance free.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.223-229
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• 2020

The present work proposes a solution to the static Boltzmann transport equation approximated by the simplified P₃ (SP₃) on angular, and the analytic coarse mesh finite difference (ACMFD) for spatial variables. Multi-group SP₃-ACMFD equations in 3D rectangular geometry are solved using the GMRES solution technique. As the core time dependent analysis necessitates the solution of an eigenvalue problem for an initial condition, this work is hence devoted to development and verification of the proposed static SP₃-ACMFD solver. A 3D multi-group static diffusion solver is also developed as a byproduct of this work to assess the improvement achieved using the SP₃ technique. Static results are then compared against transport benchmarks to assess the proximity of SP₃-ACMFD solutions to their full transport peers. Results prove that the approach can be considered as an acceptable interim approximation with outputs superior to the diffusion method, close to the transport results, and with the computational costs less than the full transport approach. The work would be further generalized to time dependent solutions in Part II.

• Structural Engineering and Mechanics
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• v.35 no.2
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• pp.127-140
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• 2010

This paper focuses on a number of criteria that enable controlling the influence of geometric simplification on the quality of finite element (FE) computations. To perform the mechanical simulation of a component, the corresponding geometric model typically needs to be simplified in accordance with hypotheses adopted regarding the component's mechanical behaviour. The method presented herein serves to compute an a posteriori indicator for the purpose of estimating the significance of each feature removal. This method can be used as part of an adaptive process of geometric simplification. If a shape detail removed during the shape simplification process proves to be influential on mechanical behaviour, the particular detail can then be reinserted into the simplified model, thus making it possible to readapt the initial simulation model. The fields of application for such a method are: static problems involving linear elastic behaviour, and linear thermal problems with stationary conduction.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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• pp.75-80
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• 2003

The structures and complexation energies of penta-O-alkylated 1b and penta-O-tert-butyl ester 1e of p-tert-butylcalix[5]arene and their simplified structures (2b and 2e) toward a series of alkyl ammonium guests have been calculated by a semi-empirical AM1 method. For AM1 calculations, complexation efficiencies of the simplified host 2e are very similar to the values of host 1e. The complexes of simplified host 2e with alkyl ammonium ions also have been optimized by ab initio HF/6-31G method. The calculated complexation efficiencies for 2e by ab initio method have been found to be bigger in magnitude than the values obtained by AM1 calculations for linear alkyl ammonium guests. Calculation results show that all of the calix[5]aryl derivatives investigated in this study have much better complexation ability toward ammonium cation without alkyl group compared with other alkyl ammonium guests. Ab initio calculations also well duplicate the molecular discriminating behaviors of calix[5]arene derivative 2e between butyl ammonium ions: $n-BuNH_3^+\;>\;iso-BuNH_3^+\;>\;sec-BuNH_3^+\;>\;tert-BuNH_3^+$.