• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.9-17
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• 2017

This study was conducted in 241 fire officers at fire stations in Daejeon Metropolitan City to determine their oral health care behavior status and obtained the following results: First, men were more likely to brush their teeth 3 times a day and women were more likely to brush their teeth 4 times a day; those who were in their twenties and had ${\leq}5$ years of career brushed their teeth for ${\geq}3$ minutes. Second, the respondents who were in their twenties and thirties and had <10 years of career were more likely to use auxiliary oral hygiene devices and fire captains and those at higher positions were more likely to have received oral health education. Third, the respondents having received oral health education were more likely to use auxiliary oral hygiene devices and to have their teeth scaling within a year. While the fire officers were fortunately at good levels of oral health care, taking the poor working environment into account, the efforts to develop job-customized oral health programs in which IT and robot technologies are combined to improve oral health and take measures to publicize the programs and to give better treatment to fire officers are expected to put them in better oral health care status.

• Journal of dental hygiene science
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• v.7 no.3
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• pp.129-133
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• 2007

This study was carried out to see the effect of dental auxiliary product groups being used in case of not being able to brush teeth. This study was executed for 70 students in the Dept. of Dental Hygiene of S Health College, and it was divided into the group which used brushing teeth, the one which used only dental auxiliary products, the one which did onion juice gargle, etc, and measured the effect on the reduction of oral malodor. The experimental results of the study were as below. 1) After onion juice gargle, in the experimental group A which brushed teeth, it showed lasting decrease of oral malodor until 20min since the experiment, and after 30min, the degree of oral malodor started to increase again. 2) After onion juice gargle, the result of the experimental group B which took only supplementary products such as garglin, chewing gum, intaking green tea with roasted rice & brushing a tongue and so on, was as follows. First, in case of experimental group BG which used garglin, until 30 min has passed since the experiment, it showed the lasting reduction of oral malodor as the same trend with the experimental group BG. Second, in chewing gum (experimental group BC), intaking green tea with roasted rice (experimental group BT), and brushing a tongue (experimental group BO), continuous reduction of oral malodor was shown until 10minutes has passed since the experiment, but, after 20minutes, we could see the degree of oral malodor started to increase again. 3) After onion juice gargle, in the experimental group C which only the degree of oral malodor was measured with the passage of time, neither brushing teeth nor using auxiliary goods, until 30min since the experiment, it showed the similar trend of the reduction of oral malodor with other experimental groups, but, it showed high degree of oral malodor, as compared with other experimental groups A and B.

• Journal of the Korean Magnetics Society
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• v.26 no.1
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• pp.31-37
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• 2016

This study considered the reduction of the detent force of a permanent magnet linear synchronous generator (PMLSG). The PMLSG has a relatively large magnetic air gap. Thus, a slotted type of stator structure is generally employed. Furthermore, the detent force, which is caused by energy imbalances owing to the interaction between tooth-slot structures and the permanent magnets (PMs), must be minimized for start-up operation. Therefore, in this paper, the methods of auxiliary teeth and a notch in the teeth are applied to reduce the detent force.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.39-40
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• 2014

In this paper, a novel 12/8 segmental rotor type switched reluctance motor (SRM) is proposed. Different from conventional structures, the proposed rotor consists of a series of discrete segments, and the stator is constructed from two types of stator poles: exciting and auxiliary poles. Moreover, in this structure short flux paths are taken and no flux reverse exists in the stator. While the auxiliary poles are not wound by the windings, which only provide the flux return path. Compared with conventional 12/8 SRM, the proposed structure increases the electrical utilization of the machine and decreases the core losses, which may lead to high efficiency. To verify the proposed structure, finite element method (FEM) is employed to get static and dynamic characteristics. Finally, a prototype of the proposed motor is tested for characteristics comparisons.

• Journal of Power Electronics
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• v.14 no.5
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• pp.852-858
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• 2014

A novel 12/10 axial field switched reluctance motor (AF-SRM) is proposed for cooling fan applications in this paper. Unlike from conventional structures, the proposed motor uses the axial field instead of the radio field, the rotor is constructed from a series of discrete segments, and the stator poles are constructed from two types of stator poles: exciting and auxiliary poles. This concept improves the torque capability of a previous design by reducing the copper volume, which leads to a higher efficiency. To verify the proposed structure, the finite element method (FEM) and Matlab-Simulink are employed to get characteristics of the proposed SRM. Finally, a prototype of the proposed motor was tested for characteristic comparisons.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.837-838
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• 2015

본 논문에서는 양측식 영구자석 선형 동기 전동기(Permanent Magnet Linear Synchronous Motor: 이하 PMLSM)의 전기자 분산배치를 위해 전기자에 보조치 및 Offset에 의해 나타나는 단부 코깅력을 해석하였다. 또한 가장 낮은 단부 코깅력을 가지는 Offset 위치에 대하여 역기전력을 분석하였으며 이에 따른 추력 특성에 대한 고찰을 수행하였다.

• Restorative Dentistry and Endodontics
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• v.42 no.2
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• pp.105-110
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• 2017

Objectives: This study investigated the cleaning ability of ultrasonically activated irrigation (UAI) and a novel activation system with reciprocating motion (EC, EasyClean, Easy Equipamentos $Odontol\acute{o}gicos$) when used with a relatively new chelating agent (QMix, Dentsply). In addition, the effect of QMix solution when used for a shorter (1 minute) and a longer application time (3 minutes) was investigated. Materials and Methods: Fifty permanent human teeth were prepared with K3 rotary system and 6% sodium hypochlorite. Samples were randomly assigned to five groups (n = 10) according to the final irrigation protocol: G1, negative control (distilled water); G2, positive control (QMix 1 minute); G3, QMix 1 minute/UAI; G4, QMix 1 minute/EC; G5, QMix 3 minutes. Subsequently the teeth were prepared and three photomicrographs were obtained in each root third of root walls, by scanning electron microscopy. Two blinded and pre-calibrated examiners evaluated the images using a four-category scoring system. Data were statistically analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). Results: There were differences among groups (p < 0.05). UAI showed better cleaning ability than EC (p < 0.05). There were improvements when QMix was used with auxiliary devices in comparison with conventional irrigation (p < 0.05). Conventional irrigation for 3 minutes presented significantly better results than its use for 1 minute (p < 0.05). Conclusions: QMix should be used for 1 minute when it is used with UAI, since this final irrigation protocol showed the best performance and also allowed clinical optimization of this procedure.

• Journal of Korean society of Dental Hygiene
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• v.14 no.6
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• pp.887-894
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• 2014

Objectives: The purpose of this study was to investigate the oral health education and oral health care in the implant wearers. Methods: A self-administered questionnaire was conducted by 253 patients in 14 different dental hospitals and clinics in Seoul and Gyeonggi-do from July 1 to September 30, 2012. The instrument was adapted from Kang and Lee, Yu and Shim, and Ko and Jang on the basis of the previous study. The questionnaire consisted of 12 questions including general characteristics of the subjects(4 questions), oral health education(3 questions), behavior and attitude of tooth brushing(3 questions), and use of auxiliary supplies(2 questions). Results: 1. 38.3% of the patients received the dental care education for the first time. The most common education method was demonstration by dental hygienists(28.9%). 26.2% of the patients wanted to know the right toothbrushing method. 2. The best toothbrushing methods were rolling method(28.9%) and Leonard's method(28.9%). 19.4% of the patients changed the toothbrushing method after education. 22.5 percent brushed their natural teeth and implant teeth by a different maneuver. 3. The interdental brush was the most commonly used product(35.8%) and most of the patients the interdental brush once a day(36.6%). 4. There was a significant difference between the frequency of toothbrushing and method(p<0.05). 5. There was a significant difference between the separate brushing of implant and natural teeth by the frequency of toothbrushing and method of education(p<0.05). 6. Use of interdental brush had an influenced on education method(p<0.05). Conclusions: Regular dental checkup and use of interdental brush can improve the oral care for the implant wearers. Regular use of interdental brush can prolong the life span of implant tooth and keep the patients' teeth in good condition.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.9
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• pp.1385-1390
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• 2015

This paper is analysis of multiple factor that should be considered in the design of an eddy current brake used as auxiliary brake system. The eddy current brake is a brake that generates a braking torque in a rotational direction opposite to the direction of the rotor by using a time-varying magnetic flux. The eddy current brake has the advantage of being able to take high current densities because this is used for a short period of time. Also, the eddy current brake is influenced by multiple factor such as number of slots, teeth width, coating thickness, air-gap length and so on. Therefore the eddy current brake was designed for use in railway application in consideration of the operation region and critical parameters.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.1067-1072
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• 2012

Recently, linear motors have been widely researched and have been increasingly used in various industrial applications. Especially, permanent magnet linear synchronous motors(PMLSMs) have been getting the spotlight in the transportation system. A PMLSM is structurally simple and has a lot of merits such as high speed, high thrust force, etc. However, in case of a long stator system which arranges armature to the full length of transportation lines, a PMLSM has some disadvantages such as the material cost increase and long manufacturing time. Hence, in order to overcome these problems, the PMLSM with stationary discontinuous armature structure and concentrated windings was proposed. However, this method occurs undesirable cogging force by outlet edge effect. The cogging force causes thrust force ripples and generates noise and vibration. Therefore, in this paper, we proposed installation method of auxiliary pole PMLSM with concentrated winding applying bifurcating in order to reduce cogging force by the outlet edge when the armature is placed in a discontinuous arrangement. Also, we have examined characteristics of outlet edge cogging force using 2-D finite element analysis(FEA).