• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.3
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• pp.74-82
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• 2001

To reduce the maintenance expense and the possibility of electric outage and/or accident, which causes the decrease in stability and reliability of transmission/distribution line, most of all, accurate measurement for the degree of contamination should be preceded. But the conventional method (brush wiping method), which is recommended in IEC 60815, has sow significant problem in the aspect of man power, expense, error, and so forth. In this investigation, we purpose the development of a new type automatic measuring apparatus, which could measure the degree of contamination on the surface of insulator in outdoor condition. To design and evaluate the apparatus, a FLUX 2D is used, and various laboratory tests, artificial contamination tests, were carried to proof the actual performance. With the result of these effort, we can get the meaningful conclusion to develope a new type automatic apparatus for contamination measurement.

• Journal of dental hygiene science
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• v.17 no.3
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• pp.267-274
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• 2017

This study aimed to compare the effectiveness of chewable toothbrush and manual toothbrush and provide basic data for recommendation of the chewable toothbrush in specific groups and situations. A total of 20 subjects participated in this study (rolling method, 10; non-rolling method, 10). After professional prophylaxis, participants used the manual toothbrush to brush their teeth for 3 minutes. After a 7-day wash-out period, participants used the chewable toothbrush according to the manufacturer's instructions. Pre- and post-plaque indexing of the teeth was performed. The dental plaque index was assessed using the Turesky Modification of the Quigley-Hein Plaque Index (TMQHPI) for amount of plaque and Silness-Loe Plaque Index (SLPI) for plaque thickness. The difference between pre- and post-dental plaque index was analyzed using a paired t-test and the Wilcoxon signed-rank test. The Mann-Whitney U test was also used to compare the dental plaque index reduction rates. The dental plaque index differed significantly between the chewable toothbrush and the manual toothbrush. The TMQHPI reduction rate was significantly different between the rolling and non-rolling method groups for the manual toothbrush but not the chewable toothbrush. The difference in SLPI reduction rate between the rolling and non-rolling method groups was significant for the manual toothbrush but not for the chewable toothbrush. Differences in the dental plaque index reduction rates between the chewable and manual toothbrushes were not significant in the non-rolling method group. The results of this study showed higher reduction rates in dental plaque with manual toothbrush use than with chewable toothbrush use. However, the non-rolling method group did not show statistically significant differences according to toothbrush type. The present study showed that a chewable toothbrush can be an alternative to a manual toothbrush for individuals who have difficulty using the generally recommended rolling method.

• The Journal of Korean Society for School & Community Health Education
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• v.9 no.1
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• pp.85-97
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• 2008

Objectives: This study was designed to understand the oral health knowledge & conduct of middle-school students, search for the learning objective and the educational method in line with the subjects and of utilizing as the basic data for an effective oral health-care program. Methods: The samples to achieve the purpose of this research are composed of 139 students in middle-school, OO county. Chungcheongbuk-do, the number of male students 64, and female students 75. Data were statistically analyzed by frequency analysis, $x^2$-test or Fisher's exact test by using SPSS WIN Ver. 12.0. Results: Among items on oral-health knowledge in middle-school students. the awareness ratio on a cause and preventive method for oral disease was surveyed to be lower than the awareness ratio on symptoms of oral disease. As a result of examining by comparing knowledge and behavior on the time of tooth brush. both awareness and behavior were the level of 50% or less than it. In particular, 46.2% perceived after lunch. but practice just accounted for 33.0%. The frequency of tooth brush a day was the largest in a case(47.5%) of doing twice a day. However. there was also the response (5.8%) with saying of brushing once or not brushing even once. Thus, the practice of tooth brush was surveyed to be very low even if being a minority of students. The frequency of taking a light meal was 68.8% in less than twice a day. However, even students of taking more than five times were surveyed to be 9.8%. Out of the whole-body health in over 50%-59.9%. the oral health was surveyed to be perceived to be very important. Compared to the awareness level on importance of a tooth, the ratio of visiting a dentistry was analyzed to be very low. Conclusions: The study results suggest that the school oral-health project was examined to have the necessity of being expanded and carried out even in middle-and-high schools, by which the specific oral-health promotion program including oral-health education in this period is developed.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.59-68
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• 2003

Background : In intubated patients, cultures of endotracheal aspirates (EA) are apt to contamination throughout the endotracheal tube. Therefore, the identification of etiologic agents via conventional EA cultures is not always reliable. In order to differentiate a pulmonary infection from a non-infectious disease, and to identify the true etiologic agent of acute pulmonary infection, blinded protected specimen brushing (PSB) was used, and its efficacy evaluated. Methods : In 51 intubated patients, with suspected pneumonia, blind PSB were performed, and the results compared with blood and EA cultures. A protected specimen brush was introduced through the endotracheal tube, and settled at the affected large bronchus. A specimen brush was introduced to the expected region using the blind method. The tip of the brush was introduced with an aseptic technique after vigorously mixed for 1 minute in $1cm^3$ of Ringer's lactate solution. The specimens were submitted for quantitative culture within 15 minutes, with a culture being regarded as positive if the colony forming units were above $10^3/ml$. Results : Of the 51 patients, 15 (29.4%) had community-acquired pneumonia (CAP), 27 (52.9%) hospital-acquired pneumonia (HAP) and 9 (17.6%) non-infectious diseases. The sensitivity and specificity of the quantitative PSB culture for the diagnosis of pneumonia were 52.4 and 88.9%, respectively. The sensitivity and specificity of EA were 78.6 and 77.8%, respectively. The blind PSB was superior to the EA for the identification of true etiologic agents. Of 53 episodes of 27 HAP patients, MRSA (Methicillin-resistant staphylococcus aureus) (41.5%) was the most common causative agent followed by Pseudomonas aeruginosa (15.1%), Klebsiella sp. (7.5%) and Acinetobacter sp. (7.5%). Conclusions : As a simple, non-invasive diagnostic modality, the blind PSB is a useful method for the differentiation of a pulmonary infection from non-infectious diseases and to identify the etiologic agents in intubated patients. A blind PSB can be performed without bronchoscopy, so is safer, more convenient and cost-effectiveness for patients where bronchoscopy can not be performed.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.3
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• pp.330-335
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• 2012

Brushless doubly-fed machine (BDFM) doesn't use brush and slip ring, and has advantages such as high system reliability, small capacity of its frequency converter, low system cost, adjustable power factor and speed, etc. At the same time, it has good applicable potentials on the variable frequency motors and the variable speed constant frequency generators. However, due to the complicacy and particularity of BDFM in the structure and operating mechanism, the effect of magnetic field modulation directly influences the operating efficiency of BDFM. To study the effect of different cage rotor structures on the magnetic field modulation of BDFM, the rotor magnetomotive force (MMF) of BDFM with cage rotor is studied by the analytical method. The components and features of rotor harmonic MMFs are discussed. At the same time, the method to weaken the higher harmonics is analyzed by the theoretic formulae. Furthermore, the magnetic field modulation mechanism is expounded on in detail and the relationship between the magnetic field modulation effect and the operating efficiency of BDFM is established. And then, a new method for estimating the magnetic field modulation effect is proposed. At last, the magnetic field modulation effects of four BDFM prototypes with different cage rotor structures are compared by the MMF analysis and the efficiency data of electromagnetic design. The results verify the effectiveness of the new method for estimating the magnetic field modulation effect of BDFM with cage rotor.

• Journal of Veterinary Clinics
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• v.30 no.1
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• pp.36-40
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• 2013

Caval syndrome is a life threatening condition caused by heavy worm burden in right cardiac chambers including right atrium, right ventricle, and vena cava and results in mechanical interference in tricuspid valvular excursion and blood flow to lower pulmonary arteries. A mechanical worm removal is the choice of option for treating this condition in dogs. In this study, we developed a new mechanical worm removal method using modified extraction brushes for treating dogs with caval syndrome. With this newly developed method, we successfully removed heartworms in two dogs with caval syndrome. Although the number of cases applied was small, authors found this method can be a good alternative retrieval method for mechanical worm removal in dogs.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.1
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• pp.33-39
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• 2022

A multi-phase brushless direct current (BLDC) motor is widely used in large-capacity electric propulsion systems such as submarines and electric ships. In particular, in the field of military submarines, the polyphaser motor must suppress torque ripple in various failure situations to reduce noise and ensure stable operation for a long time. In this paper, we propose a polyphaser current control method that can improve efficiency and reduce torque ripple by minimizing the increase in stator winding loss at maximum output torque by controlling the phase angle and amplitude of the steady-state current during open circuit failure of the stator winding. The proposed control method controls the magnitude and phase angle of the healthy phase current, excluding the faulty phase, to compensate for the torque ripple that occurs in the case of a phase open failure of the motor. The magnitude and phase angle of the controlled steady-state current are calculated for each phase so that copper loss increase is minimized. The proposed control method was verified using hardware-in-the-loop simulation (HILS) of a 12-phase BLDC motor. HILS verification confirmed that the increase in the loss of the stator winding and the magnitude of the torque ripple decreased compared with the open phase fault of the motor.

• Journal of Periodontal and Implant Science
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• v.53 no.4
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• pp.295-305
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• 2023

Purpose: Various methods have been proposed to achieve the nearly complete decontamination of the surface of implants affected by peri-implantitis. We investigated the in vitro debridement efficiency of multiple decontamination methods (Gracey curettes [GC], glycine air-polishing [G-Air], erythritol air-polishing [E-Air] and titanium brushes [TiB]) using a novel spectrophotometric ink-model in 3 different bone defect settings (30°, 60°, and 90°). Methods: Forty-five dental implants were stained with indelible ink and mounted in resin models, which simulated standardised peri-implantitis defects with different bone defect angulations (30°, 60°, and 90°). After each run of instrumentation, the implants were removed from the resin model, and the ink was dissolved in ethanol (97%). A spectrophotometric analysis was performed to detect colour remnants in order to measure the cumulative uncleaned surface area of the implants. Scanning electron microscopy images were taken to assess micromorphological surface changes. Results: Generally, the 60° bone defects were the easiest to debride, and the 30° defects were the most difficult (ink absorption peak: 0.26±0.04 for 60° defects; 0.32±0.06 for 30° defects; 0.27±0.04 for 90° defects). The most effective debridement method was TiB, independently of the bone defect type (TiB vs. GC: P<0.0001; TiB vs. G-Air: P=0.0017; TiB vs. GE-Air: P=0.0007). GE-Air appeared to be the least efficient method for biofilm debridement. Conclusions: T-brushes seem to be a promising decontamination method compared to the other techniques, whereas G-Air was less aggressive on the implant surface. The use of a spectrophotometric model was shown to be a novel but promising assessment method for in vitro ink studies.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.309-320
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• 2007

Purpose: This study was to evaluate the removal effect on artificial plaque from RBM treated implant surfaces that are exposed due to peri-implantitis. Materials and methods: Artificial plaque with Streptococcus mutans and acquired pellicle adhered to RBM treated implant discs. Study materials divided into one control and six test groups. In test groups, physical and chemical methods used to remove plaques. Prophyflex, Professional Mechanical Tooth Cleaning (PMTC) and interdental brush as mechanical treatments and 0.1% Chlorhexidine, Citric acid, HCl tetracycline as a chemical treatment were used. To analyses the study, disc weight was measured for remaining plaque quantities and SEM(Scanning Electronic Microscope) findings was taken for evaluation of surfaces. Results: 1. In weight changes, there was significant difference between each treatment group and the control group (p<0.05). Therefore all treatment methods using this study have good ability for remove plaques. 2. In weight changes, there was no significant difference between mechanical and chemical group, and there were no significant differences between each groups (p>0.05). 3. SEM findings after mechanical treatment disclosed as follows; Prophyflex group looked like sound implant surface, and there were some paste on implant surface at PMTC group, and there were some artificial plaque at interdental brush group. 4. SEM findings after chemical treatment disclosed as follows; there were some dark lesions which were supposed as the product from Streptococcus mutans at Chlorhexidine, Citric acid and HCl tetracycline groups. Conclusion: All six methods using in this study have good ability to remove artificial plaque on RBM treated implant. According to SEM findings, prophyflex is a superior method for removing of dental plaque among test groups.

• Journal of Korean society of Dental Hygiene
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• v.11 no.1
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• pp.13-27
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• 2011

Objectives : The purpose of this survey research was to investigate the relationship among oral health State, behavior and knowledge of oral health of patients who participate in dental hygiene students voluntarily. Methods : The subject in this were patients who got a scaling at the oral hygiene practice lab in the department of dental hygiene in S university dental clinic from April 1 to May 31, 2010. For the data analysis, an SPSS WIN 11.5 program was used and its signification level was 0.05. Results : 1. For the oral health state according to sex distinction, it showed the men's 0.78 MT index was higher than women's 0.48 MT index and statistically significant difference. For FT index, women(4.72) was higher than men(3.50) and it showed statistically significant difference(p<0.05). 2. For the oral health state according to age distinction, DT index of under 20years(2.44) was higher than the others and it showed statistically significant difference(p<0.05). 3. For the oral health state according to marriage distinction, not married DT index(1.59) was higher than married DT index(2.56) and it showed statistically significant difference(p<0.05). 4. For the oral health behavior according to age distinction, 87.0% 20~29years patients replied as I have experience of my teeth scaled and it showed statistically significant difference. 18.5% more than 30 years replied as I use interdental brush and it showed statistically significant difference. 18.5% more than 30 years replied as I use powered brush and it showed statistically significant difference(p<0.05). 5. For the oral health state according to oral health behavior distinction, there were significant difference that regular visit of dental clinic, experience of teeth scaled, toothbrushing, oral hygiene device(p<0.05). 6. For the oral health state according to oral health knowledge distinction, there were significant difference that toothbrushing time after each meal, appropriate toothbrushing time, toothbrushing method, dental caries foods(p<0.05). Conclusions : I suggest with the result of the study that there was a very close relationship between oral health status, behavior and knowledge of oral health. Therefore student of the dental hygiene should be encouraged to pay more attention to oral health care of the patient, and they should be well educated oral health care personnels who volunteers in practice for oral prophylaxis.