• 센서학회지
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• 제26권1호
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• pp.39-43
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• 2017

Development of vision system as a nondestructive evaluation system can be very useful in screening the defective mechanical parts before they are assembled into the final product. Since the tens of thousands of the mechanical parts are used in an automobile carefully inspecting the quality of the mechanical parts is very important to maximize the performance of the automobile. To sort out the defective mechanical parts before they are assembled, auto parts fabrication companies employ various inspection systems. Nondestructive evaluation systems are getting rapidly popular among various inspection systems. In this study, we have developed a vision system to inspect the inside of the brake caliper, a part that is used to compose a brake which is the most important to the safety of the drivers and the passengers. In a brake caliper, a piston is pushed against the brake disk by oil pressure, causing a friction to damp the rotation of the wheel. Inside the caliper, a groove is positioned to adopt an oil seal to prevent the oil leaks. Inspecting the groove with our vision system, we could examine the existence of the contaminants which are normally the residual tiny pieces from the machining process. We used a high resolution GigE camera, 360 degree lens to look in the inside view of the caliper at once, and a special illumination system in this vision system. We used the edge detection technique to successfully detect the contaminants which were in the form of small metal chips. Labview graphical program was used to process the digital data from the camera and to display the vision and the statistics of the contaminants. We were very successful in detecting the contaminants from the various size calipers. We think we are ready to employ this vision system to the caliper production factories.

• 대한치과의사협회지
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• 제54권11호
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• pp.865-873
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• 2016

Background/Purpose: The purpose of this study was to evaluate the effect of Nd:YAG irradiation on adherence of retrograde filling materials (mineral trioxide aggregate [MTA] and Super-EBA) by micro-computed tomography (CT) measurement and to observe the dentinal surface after irradiation by scanning electron microscopy (SEM). Materials and methods: Forty retrofilling models using extracted human teeth were divided into four groups according to the material and method used: ProRoot MTA (MTA group), Super-EBA (EBA group), MTA with Nd:YAG laser irradiation (LMTA group), and Super-EBA with Nd:YAG laser irradiation (LEBA group). All specimens were stored in 100% humidity for 24 hours until micro-CT was performed. The gap volume of the tooth/material interface was measured using the CTAn program. In six samples, the laser-irradiated dentin surface was observed using SEM. Results: The mean percent difference in gap volume was not statistically significant between the Nd:YAG laser-irradiated groups and non-irradiated in both materials(P > 0.05). The gap volume in the MTA group was significantly lower than that in the EBA group (P < 0.05). Examination of the non-irradiated specimens by SEM showed patent dentinal tubules. In contrast, alterations in the texture of the dentin surface and obliteration of the dentinal tubules were evident in the Nd:YAG laser-irradiated specimens. Conclusion: In this study, changes in the dentinal surface after Nd:YAG irradiation did not affect adherence between the apical filling material and the dentin wall.

• Computers and Concrete
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• 제20권3호
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• pp.275-282
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• 2017

Grouting is an operation often carried out to consolidate and seal the rock mass in dam sites and tunnels. One of the important parameters in this operation is grouting pressure. In this paper, analytical models used to estimate pressure are investigated. To validate these models, grouting data obtained from Seymareh and Aghbolagh dams were used. Calculations showed that P-3 model from Groundy and P-25 model obtained from the results of grouting in Iran yield the most accurate predictions of the pressure and measurement errors compared to the real values in P-25 model in this dams are 12 and 14.33 Percent and in p-3 model are 12.25 and 16.66 respectively. Also, SPSS software was applied to define the optimum relation for pressure estimation. The results showed a high correlation between the pressure with the depth of the section, the amount of water take, rock quality degree and grout volume, so that the square of the multiple correlation coefficient among the parameters in this dams were 0.932 and 0.864, respectively. This indicates that regression results can be used to predict the amount of pressure. Eventually, the relationship between the parameters was obtained with the correlation coefficient equal to 0.916 based on the data from both dams generally and shows that there is a desirable correlation between the parameters. The outputs of the program led to the multiple linear regression equation of P=0.403 Depth+0.013 RQD+0.011 LU-0.109 V+0.31 that can be used in estimating the pressure.

• 생체재료학회지
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• 제22권4호
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• pp.346-351
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• 2018

Background: Carbonate apatite ($CO_3Ap$) and silica-calcium phosphate composite (SCPC) are bone substitutes with good prospect for dental application. SCPC creates a hydroxyapatite surface layer and stimulate bone cell function while, $CO_3Ap$ induce apatite crystal formation with good adaptation providing good seal between cement and the bone. Together, these materials will add favorable properties as a pulp capping material to stimulate mineral barrier and maintain pulp vitality. The aim of this study is to investigate modification of $CO_3Ap$ cement combined with SCPC, later term as $CO_3Ap-SCPC$ cement (CAS) in means of its chemical (Calcium release) and physical properties (setting time, DTS and pH value). Methods: The study consist of three groups; group 1 (100% calcium hydroxide, group 2 $CO_3Ap$ (60% DCPA: 40% vaterite, and group 3 CAS (60% DCPA: 20% vaterite: 20% SCPC. Distilled water was employed as a solution for group 1, and $0.2mol/L\;Na_3PO_4$ used for group 2 and group 3. Samples were evaluated with respect to important properties for pulp capping application such as pH, setting time, mechanical strength and calcium release evaluation. Results: The fastest setting time was in $CO_3Ap$ cement group without SCPC, while the addition of 20% SCPC slightly increase the pH value but did not improved the cement mechanical strength, however, the mechanical strength of both $CO_3Ap$ groups were significantly higher than calcium hydroxide. All three groups released calcium ions and had alkaline pH. Highest pH level, as well as calcium released level, was in the control group. Conclusion: The CAS cement had good mechanical and acceptable chemical properties for pulp capping application compared to calcium hydroxide as a gold standard. However, improvements and in vivo studies are to be carried out with the further development of this material.

• 보건교육건강증진학회지
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• 제17권1호
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• pp.131-154
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• 2000

This study was conducted to provide basic data for development of public information program and public policy which could prevent the medicine abuse in Korea, examining the level of knowledge of medicine and its related factors. Data were collected from the 2,011 residents who live in mtropolitan cities, large-sized cities, small and medium cities, and small towns The results of this study are summarized as follows. 1) In case of purchasing of medicines in pharmacy, 67.3％ of the respondents chose the medicines through recommendations of the professionals such as pharmacists and doctors, while 32.7％ of the respondents chose the medicine through self-judgement, advertizing, or recommendation of relative. 2) 64.7％ of the respondents obtained the information on medicines through TV. It appeared to be higher in the groups of female of the twenties, the unmarred, a brother and sister threesome, highschool graduates, housewives, residents in small and medium cities, atheists, and the middle class, displaying the significant difference from the other groups. 3) 40.5％ of the respondents recognized the side effect of the medicine when they took the medicine, while 34.4％ did not recognize it. The rate of experience in the side effect was 39.7％. The informations on the medicine abuse and the risk of addiction were obtained through broadcast media (47.9％), publications (12.1％), and health professionals (11.6％). 4) 81.1％ of the respondents experienced taking of the fatigue relieving medicine. The experience in taking of the fatigue relieving medicine appeared to be higher in the groups of the forties. the married. a brother and sister threesome. highschool graduates. persons engaging in farming, livestock raising, and forestry, the residents in small towns, and Christians. Each group displayed the significant difference from the other groups. 5) According to the level of knowledge of medicines, the respondents marked average 11.7 ± 3.76 points on the base of 24 points. It appeared to be higher in the groups of female of the twenties, a brother and sister foursome, college graduates, teachers, Catholics, and the middle class, displays the significant difference from the other groups. 6) According to the experience in taking of health medicine and health food, 81.1％ of respondents had the experience in taking ‘the fatigue relieving medicine’; 72.4％ ‘carrot or vegetable juice’; 69.5％ ‘ginseng’; 63.0％ ‘mushroom’; 42.5％ ‘dog meat’; 38.0％ ‘aloe’; 36.4 ‘deer antlers’; 11.4％ ‘snake’; 2.0％ ‘the penis of a fur seal’. 7) The factors influencing the level of knowledge of medicine include experiences in taking of the tonic, the fatigue relieving medicine, and the nutritive medicine, economic status, the number of brothers and sisters, education level, marital status, father's education level, and age. The factors influencing the experience in side effect of medicine are experiences in taking of the fatigue relieving medicine, the nutritive medicine, and the tonic, sex, age, education level, father's education level, marital status, economic status, religion, and the number of brothers and sisters. In conclusion, it is estimated that the level of knowledge of medicines is significantly low in Korea. Especially, it is found out that workmen, students, the upper class, the class of low education level, and persons engaging in farming, livestock raising, and forestry neglect importance of knowledge of medicine. Therefore, it is necessary for public authority, associations related, and health professionals to develop programs for public information and education to help people obtain basic knowledge of medicine.