• Product Safety
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• s.103
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• pp.50-55
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• 2002

기술표준원은 중국의 강제인증제도가 국내제품(CCEE마크)과 수입 제품(CCIB마크)으로 이원화 하여 운영해 오던 것을 2001. 12. 3자로 단일 강제인증제도(CCC마크)로 통합하여 2002. 5. 1부터 시행됨에 따라 중국 제도변경에 따른 혼선 및 대중국 수출에 차질이 없도록 CCC마크 대상 품목과 관련된 조합 및 업체 등의 수출입관계자를 대상으로 설명회를 2002. 4. 24. 기술표준원 대강당에서 개최한 바 잇습니다. 기술표준원은 설명회효과를 높

• Korean Journal of Remote Sensing
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• v.6 no.1
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• pp.1-9
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• 1990

This paper presents a method of the constructing DEM(Digital Elevation Model) from the image data acquired from a commercial map using the scanner. Data acquistion, mark elimination, linking the broken line, elevation interpolation and 3D display processing are performed and the results are satisfatory.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.199.2-199.2
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• 2008

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.146.3-146
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• 2001

It has been integrated into several navigation systems. This paper shows that system recognizes difficult indoor roads and open area without any specific mark such as painted guide tine or tape. In this method, Robot navigates with visual sensors, which uses visual information to navigate itself along the road. An Artificial Neural Network System was used to decide where to move. It is designed with USB web camera as visual sensor.

• The Journal of the Convergence on Culture Technology
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• v.3 no.4
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• pp.43-53
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• 2017

This study is focused on mediating effect of academic motivation between the educational environmental factors on Self-determination Theory and Reward and Punishment Mark System. For the purpose of this study, a questionnaire survey uses a scale being developed through the educational environmental factors on self-determination, academic motivation, and academic achievement. The survey was conducted among 202 students in middle and high school in Seoul. First, autonomy of variables of educational environment based on self-determination theory has influenced on internal and external academic motivation, confidence makes internal and reasonable motivation high, and relationship makes demotivation low. Second, Reward and Punishment Mark System which has recently been replaced traditional punishment doesn't have influenced on academic motivation of students. Third, internal motivation has positively influenced on willingness to take classes and academic achievement analyzing the effect of academic motivation sub-factors on academic achievement. Therefore, this study suggests that autonomy, confidence, and relationship in self-determination theory make academic motivation and willingness to take classes high.

• Journal of Technologic Dentistry
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• v.12 no.1
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• pp.73-93
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• 1990

The study objected to the 120 persons out of 360 persons who have registered under the association of the dental technicians in Pusan to grasp contents about improvement of life long education of the present day of November, 1987, and its results, which we have acquired by this study were as follows : 1. A sense of satisfaction toward the system of life long education appeared as unsatisfaction and its unsatisfaction decreased from the rate of member's attendance or exam. marks, the contents of education, and place of education. 2. The problem of the exam. mark which derived by the presence by the substitute appeared which 46.7 percent(56 persons), lack of opportunity for the recompletion at branch association appeared which 19.2%(23 persons), given 4. exam. marks at the over all scientific contest was appeared 14.2 percent(17 persons), relation which legal treatment when ones didn't completed exam. mark was appeared 10.8 percent(13 persons) and lastly, appeared 8.3 percent (10 persons) with time of delivery of the exam mark card. 3. The frequency of the opening for the life long education which related with the rate of members attendance was fixed as nowadays two times per annually, but they perferred the opening per academic blanch once out of the firest half year and the latter half of the year and, they liked the openings at the first week or second week and preferred the holding on saturdays and sundays. 4. The subject of the life long education have appeared the opinion that the thesis was lop-sided toward the allocation of time schedule of lecture appeared the opinion of which they perferred the rate of an hour of cultural subject and two hours of major studies, and invitation for an instructor they preferred one dentist, one member, one dean for the cultural subject, and there are lots of opinions which they wished display of materials. 5. A sence of satisfaction about the place they perferred was decreased such as ; an auditorium concerned of the colleges was 46.7 Percent(56 Persons), hotels 26.7 Percent(32 Persons), an auditorium of the general hospital 20 percent(24 persons) 6. And lastly, there are lots of opinions who have required the necessities to constitute for the academic branch.

• Journal of the Korean Ceramic Society
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• v.22 no.6
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• pp.42-52
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• 1985

Several $Al_2O_3$-based polycrystalline which had different dopant ratio in the range of 0.5mol% were prepared by doping pure $Cr_2O_3$ $HfO_2$. Single crystalline which had same composition with above polycrystalline were made by means of floating zone method. This study examined the role of each dopant for enhancing the mechanical properties of $Al_2O_3$-based Ceramics. Optical micrographs $({ imes}200)$ of $Al_2O_3-Cr_2O_3$ single crystal showing not only radial crack (rc) on the specimen surface but median crack(mc) and lateral crack(lc) under surface at the edge of indentation mark. Fracture toughness of Al2O3-based Ceramics was increased with $ZrO_2$ content. Alloying effect of $Cr_2O_3$ contributed to the hardness of $Al_2O_3$ based ceramics.

• Journal of the Korean Ceramic Society
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• v.22 no.6
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• pp.37-41
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• 1985

Several $Al_2O_3$-based polycrystalline which had different dopant ratio in the range of 0.5mol% were prepared by doping pure $Cr_2O_3$, $ZrO_2$, $HfO_3$ Single crystalline which had same composition with above polycrystalline were made by means of floating zone method. This study examined the role of each dopant for enhancing the mefchanical properties of $Al_2O_3$-based Ceramics. Optical micrographs $({\times}200)$ of $Al_2O_3-Cr_2O_3$ single crystal showing not only radial crack (rc) on the specimen surface but median crack (mc) and lateral crack (lc) under surface at the edge of indentation mark. Fracture toughness of $Al_2O_3$-based Ceramics was increased with $ZrO_2$ content. Alloying effect of $Cr_2O_3$ contributed to the hardness of $Al_2O_3$ based ceramics.

• Journal of the Korean Ceramic Society
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• v.24 no.5
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• pp.484-490
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• 1987

Diffusion coupling experiment was done to study expansion of body and soild reaction in BaCO3-TiO2 system. Specimen of BaCO3 and TiO2 was formed with Pt-mark's method. Each specimen was fired at interval of 25℃ from 900℃ to 1000℃ for 2hrs. After that, specimen was fixed with resin and polished. Product layers of specimen were observed with SEM and EDS. The result were following; 1. Diffusion component is Ba2+, which diffuse toward TiO2. 2. Large crack between layer of BaCO3 and Ba2TiO4 was generated because of difference of thermal expansion coefficient. 3. Ba2TiO4 is formed to TiO2 body by the reaction of BaTiO3 and BaO and its structure is very porous. 4. BaTiO3 changes immediately to Ba2TiO4 by the reaction of BaO. But BaTiO3 which formed by the reaction of TiO2 and Ba2TiO4 exsists as layer because the diffusion distance of Ba2+ is far.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.3
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• pp.298-306
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• 2008

STATEMENT OF PROBLEM: Effect of surface treatment of ceramic under loading does not appear to have been investigated. PURPOSE: The aim of this study was to investigate the effect of surface treatment of esthetic ceramic, which is performed to increase the bonding strength, on the fracture stress under controlled cyclic loading condition. MATERIAL AND METHODS: Sixty 1.0 mm-thick specimens were made from Mark II Vitablocs (Vita Zahnfabrik, Germany) and divided into 3 groups: polished (control), sandblasted, and etched. Specimens of each group were bonded to a dentin analog material base including micro-channels to facilitate the flow of water to the bonding interface. Bonded ceramics were cyclically loaded with a flat-end piston in the water (500,000 cycles, 15Hz). Following completion of cyclic loading, specimens were examined for subsurface crack formation and subsequent stress was determined and loaded to next specimen by the staircase method according to the crack existence. RESULTS: There were significant differences of mean fatigue limit in the sandblasted (222.86 ${\pm}$ 23.42 N) and etched group (222.86 ${\pm}$ 14.16 N) when compared to polished group (251.43 ${\pm}$ 10.6 N) (P<.05; Wald-type pair-wise comparison and post hoc Bonferroni test). Of cracked specimens, surface treated group showed longer crack propagation after 24 hours. All failures originated from the radial cracking without cone crack. Fracture resistance of this study was very low and comparable to failure load in the oral cavity. CONCLUSION: Well controlled cyclic loading could induce clinically relevant cracks and fracture resistance of Mark II ceramic was relatively low applicable only to anterior restorations. Surface treatment of inner surface of feldspathic porcelain in the matsicatory area could influence lifetime of restorations.