• The Journal of Advanced Prosthodontics
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• v.10 no.2
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• pp.132-137
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• 2018

PURPOSE. The purpose of this study was to evaluate and compare three polishing systems on the surface roughness and phase transformation of monolithic zirconia. MATERIALS AND METHODS. 100 disk shaped specimens (10 mm diameter, 3 mm thickness) were fabricated from monolithic zirconia blocks. 20 specimens were left as a control group and remaining specimens were grinded by diamond bur to simulate the occlusal adjustments. Grinded specimens were randomly divided into 4 groups: group G (no polishing), group M (Meisinger, zirconia polishing kit), group E (EVE Diacera, zirconia polishing kit), and group P (EVE Diapol, porcelain polishing kit). Surface roughness was measured with profilometer and surface topography was observed with SEM. XRD analysis was performed to investigate the phase transformation. Statistical analysis was performed with one-way ANOVA and Tukey's post hoc tests at a significance level of P=.05. RESULTS. All polishing groups showed a smoother surface than group G. Among 3 polishing systems, group M and group E exhibited a smoother surface than the group P. However, no significant differences were observed between group M and group E (P>.05). Grinding and polishing did not cause phase transformations in zirconia specimens. CONCLUSION. Zirconia polishing systems created a smoother surface on zirconia than the porcelain polishing system. Phase transformation did not occur during the polishing procedure.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.595-599
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• 1998

The present study was undertaken to develop the kit for indirect immunofluorescence antibody test(IFAT) and to investigate the prevalence of N caninum in cattle and dogs in Korea. The neo-antigen kit of IFAT developed in our laboratory was proved diagnostic efficacy by compared with the kit of veterinary medical research and development(VMRD). A survey of N caninum infections among cow and dogs in elevn areas of southern part of country was performed using a IFAT. The infection rate of 190 nationwide cattle was 8.4%(16/190) but was 75%(45/60) at P area in Chunnam province where the cattle showed the abortion repeatedly. Any of the dogs was not N caninum -positive in the Kangwon and Kyonggi areas.

• Korean Journal of Animal Reproduction
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• v.13 no.3
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• pp.157-163
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• 1989

This stduy was carried out to evaluate the ability of clinical application of pregnancy diagnosis based upon the determination of progesterone in serum, utilizing EIA-kit of progesterone concentrations in the serum were assayed by radioimmunoassay. 1. The progesterone concentrations of the pregnant cows(2.40$\pm$0.34ng/ml) were significantly higher than those of non-pregnant cows(1.03$\pm$0.09ng/ml), and thereafter began to increase and maintained high levels. 2. During 20 to 22 days after artificial insemination, the accuracy of pregnancy diagnosis from EIA-kit of progesterone were 95.0% for non-pregnant cows, and 92.3% for pregnant cows. 3. During 20 to 22 days after artificial insemination, the accuracy of pregnancy diagnosis from serum progesterone concentrations were 100% for non-pregnant cows(<1.4ng/ml), and 96.2% for pregnant cows( 2.0ng/ml). The average overall accuracy of prediction for pregnant and non-pregnant cows were 98.1%. 4. Accordingly, the pregnancy diagnosis from EIA-kit of progesterone is thought to be recommendable because this early diagnostic means are simple with accurate results.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.67-80
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• 1990

This study was performed for elucidating the effects on surface polishing of composite resins. In this study, Silux(microfilled), Graft(hybrid), Bisfil- I (hybrid posterior) and Hi-pol(conventional) were used. Sixty specimens were made with 4 brands of composite resins and Optilux system in $2.0{\times}1.3{\times}1.0cm$ resin block which has a cavity with 0.5cm diameter and 0.5cm depth. Polishing was done with #600 sand paper and Soflex, Super-snap, Micron finishing system, or Composite polishing kit. Final polished surfaces were measured by roughness tester(Kasaka Lab. Ltd., Japan) and image analyser(Omnimet Image Analyser, Buehler, USA). The results were as follows, 1. The celluloid strip produced the smoothest surfaces. 2. Light curing microfilled composite resin, Silux, had smoother surface than any others. 3. The surfaces polished by Soflex were smoothest. 4. Aluminum oxide disk, Soflex and Super-Snap, made smoother surface than diamond bur, M.F.S., or silicon point, Composite polishing kit. 5. The roughness values of surface polished by M.F.S. composed of diamond burs, were less than those of Composite polishing kit made from silicone points.

• Journal of Practical Engineering Education
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• v.7 no.2
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• pp.89-95
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• 2015

IT technologies are closely related to our daily life, and we are experiencing the emergence of new IT devices every day. The ongoing rapid progress of IT technology results in the increasing demand of experienced software & hardware engineers, and leads to the short life cycle of lab kits. However, the normally small to medium sized manufacturers of lab kits usually cannot even afford to support timely update and upgrade of their own kits. In this paper, we propose a way of effectively running an IT course by building a Raspberry Pi based kit. Raspberry Pi has features that allow us to not only timely update/upgrade the kit, but also expose students to various IT fields.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.101-108
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• 2017

Recently, the patent rights for 3D printing technology have expired, while 3D printers with RP (Rapid Prototyping or Additive Manufacturing) and 3D printing technologies are receiving attention. In particular, the development of 3D printers is rapid in Korea, thanks to the increasing sales and popularity of FDM (Fused Deposition Modeling or Fused Filament Fabrication) 3D printers. However, the quality and productivity of the FDM 3D Printer are not good, so customers prefer the DLP (Digital Light Processing) method to avoid these shortcomings. The DLP method has high quality and productivity. However, because of the stereolithography equipment, it has few studies compared to optimal values for elements then FDM 3D printing study. In this study, to find the optimal conditions for 3D printing with the DLP method, the aim is to obtain the optimal values (strength, final time, quality) by changing the light exposure time, layer thickness, and z-axis speed.

• Journal of The Korean Association of Information Education
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• v.14 no.1
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• pp.123-130
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• 2010

In this paper, we introduce a new programming learning system for young students. The programming learning system consists of a LED display kit and a web-based flowchart system. The LED display kit acts as an output device by way of displaying lights while following a set of instructions given through a flowchart programming. In the flowchart system, the students use symbolic variables for the calculation and can get various displays or animations after creating a flowchart by drag-and-drop. Then we describe the survey results of various programming classes using our system between fall 2005 and spring 2009. The programming teaching was conducted with diverse groups such as elementary school students, gifted students, college students, and teachers etc. The responses from our in class surveys were generally positive.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.854-858
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• 2005

A Lactobacillus isolate was collected from the feces of a healthy Korean individual and named as Lactobacillus ruminus SPM0211. It was further characterized by subjecting it to an antibiotic resistance test and genetic analysis. In the antibiotic resistance test, all tested Lactobacillus spp. were classified as 'high resistance' for multiple antibiotics, such as isoniazid, ethambutol, cycloserine, and vancomycin. L. ruminus SPM0211 was classified as 'high resistance' for streptomycin also, while the other tested Lactobacillus spp. were classified as low resistance. This suggests that the antimicrobial spectra may be a good indicator in the discrimination of this strain among the tested Lactobacillus spp. In a polymerase chain reaction-random amplified polymorphic DNA (PCR-RAPD) analysis using the Microbial Uniprimer kit, L. ruminus SPM0211, and L. suebicus were clustered as a group with a 74.3% similarity level, suggesting that these two species are genetically related. Thus, our data suggest that the PCR-RADP method using the Microbial Uniprimer kit may be valuable in discriminating L. ruminus SPM0211 from other Lactobacillus spp.

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.143-148
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• 2009

About 70% of Korea consists of mountainous areas, and during the construction of many roads and railroads, cut slopes are inevitably formed. The rainy season, frost heaving in winter, and thawing in spring can all cause rockfalls and landslides. The failure of these slopes is increasing every year, causing damage to vehicles, personal injury and even death. To protect people and property from such damage, a real-time monitoring system is needed to detect the early stages of slope failures. The GMG placed TRS sensor units in the slopes to monitor them in real-time. But due to its reliance on data lines and power lines, the system is vulnerable to lightning damage. The whole system can be damaged by a single lighting strike. Consequently, for the purposes of this paper we propose the use of the Ubiquitous Sensor Network (USN) which follows the IEEE 802.1.4. By using the USN system we can minimize lightning damage and can monitor the movement of the slopes consistently.

• Journal of the Korean Institute of Educational Facilities
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• v.17 no.2
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• pp.3-12
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• 2010

The purpose of this study was to provide the planning guideline for the multi-purposed classroom in the elementary school and middle school using questionnaire and user participation method. As the user participation method, the design workshop in the study contains participation techniques, community action planning, and participation game. The design workshop used the design kit as a communication tool. Four user groups, selected from teachers and child in the elementary school and middle school, to be reconstructed, participated in a design workshop with design kit, and each group produced their own plans. The result of this study is as follows; (1) Teachers wanted multi-purposed classroom to be used by two classes. (2) The size of the multi-purposed classroom was preferred 1.5 times(30 py.) of the regular classroom. (3) By considering the characteristics of students it was required the open space in elementary, but required it to be separated from the regular classroom in middle school. (4) Through the analysis, we could grasp the processes that the users' needs were practically applied to design. Our design workshop method should be hereafter modified and advanced, but showed the usefulness in many aspects.