가상 생리적압력하에서 Porcelain Laminate Veneer 접착시 상아질 접착제의 변연 누출에 관한 연구

최영진,이호용,Choi, Young-Jin,Lee, Ho-Young 대한치과보철학회 1993 대한치과보철학회지 Vol.31 No.1

The purpose of this study was to evlauate the microleakage of 3 dentin bonding agents using different dentin pretreatment method under simulated physilogic pressure in cementing the porcelain laminate veneer. Noncarious 60 human maxillary molars were selected and randomly assigned to 4 groups of 15 each. The group with the margin placed on the enamel was classified as the control and the groups with the margin placed on root surface were subdivided into 3 groups according to the dentin bonding agents used. The group using All Bond 2 was classified as experimental group 1, the group using Scotchbond MP was classified as experimental group 2, and the group using Gluma was classified as experimental group 3. Roots were removed at 3mm below the cementoenamel junction, and reductions of the teeth for the porcelain laminate veneer were done on the mesial 1/2 of the buccal surface of each teeth. The pulp was extirpated and the pulp chamber was cleaned with 37% phosphoric acid for the patency of dentinal tubule. Under simulated physiologic pressure, porcelain laminate veneers were cemented to the teeth using each dentin bonding agent and luting cement. After cementation, all samples were stored at 36t in water for 24 hours and thermocycled for 1500 cycles, then immersed in 0.5% basic fuchsin solution and the teeth were sectioned longitudinally by using diamond saw and the extent of microleakage was measured. The following results were obtained, 1. Microleakage was observed in a few samples of control group but all the samples of experimental groups. 2. The control group showed the less extent of microleakage than the experimental groups. In experimental groups the experimental group 1 & the experimental group 2 showed similiar extent of microleakage and the experimental group 3 showed the greater extent of microleakage than other groups. Conclusively, practicing the porcelain laminate veneers in the clinic, although the margin of the porcelain laminate veneer should be placed on enamel, in the case that it is inevitable to place the margin of the porcelain laminate veneer on the root surface, it is recommened to use dentin bonding agents which use no dentin pretreatment or a dentin pretreatment which can leave the smear plugs.

하나로 조사시험용 다공 원통헝 구조물의 온도해석

최영진,강영환,이영신,Choi Young-Jin,Kang Young-Hwan,Lee Young-Shin 한국전산구조공학회 2004 한국전산구조공학회논문집 Vol.17 No.4

재료나 핵연료조사시험에서 다공원통형구조물의 모든 구성품에서 감마열 및 fission과 같은 열원이 발생한다. 본 연구는 조사시험중 다공원통형구조물의 열적건전성을 평가하기 위해 온도분포에 대한 일반해를 구하는데 그 목적이 있다. 다공원통형 구조물의 온도해석을 위해 2차원 열전토 방정식을 이용하였다. 유한요소해석은 ANSYS 6.1을 이용하여 수행하였다. 다공원통형 구조물의 온도해석에서 이론해석결과와 유한요소해석결과는 홀의 개수가 3개 이하에서는 온도가 서로 잘 일치하는 것으로 나타났다. 구조물의 홀 개수가 4개일때, 온도분포해석에 대한 두 결과의 차이가 증가하였다. During the irradiation tests of material and fuel rod, all components of the cylindrical structure with multiple holes act like heat sources due to high gamma heat and fission heat. The objective of this study is to formulate the general solution for the temperature distribution to estimate the thermal integrity of structure during irradiation tests. For the temperature distribution analysis, the two-dimensional heat conduction theory is used. The unmerical analysis is performed by the commercial finite element analysis code, ANSYS 6.1. If the cylindrical structure with hole number would not exceed three holes, the analysis results and finite element results are good agreement together. For the structure with four holes, the discrepancy between FE results and analysis results of the structural temperature distribution is increased.

LS-DYNA3D 및 ABAQUS/Explicit Code를 이용한 사용후 핵연료 운반용기의 자유낙하 충격특성연구

최영진,김승중,김용재,이재형,이영신,Choi, Young-Jin,Kim, Seung-Joong,Kim, Yong-Jae,Lee, Jae-Hyung,Lee, Young-Shin 한국전산구조공학회 2005 한국전산구조공학회논문집 Vol.18 No.1

방사선물질을 수송하기 위한 용기는 가상 사고조건에서도 안전해야만 한다. 운반용기 설계요구조건은 실험 및 유한요소 해석을 통해 구조적 건전성을 확보하여야 한다. 최근에는 실험보다 유한요소해석을 이용한 방법이 상대적으로 비용이 적기 때문에 주로 사용된다. 그러나 기계적인 반응이 복잡하기 때문에 프로그램을 적용하는 사용자의 방법에 의해 결과가 결정되고 해석하는 동안 여러가지 문제를 발생시킬 수 있다. 본 논문에서, 유한요소해석은 LS-DYNA3D와 ABAQUS/Explicit을 이용하여 운반용기의 9m 자유낙하충격실험에 대한 해석기술과 여러가지 손상을 갖는 경우를 발견하기 위해 연구하였다. 운반용기의 각각의 경우를 비교하고 사용후 핵연료 운반용기의 낙하 실험에 대해서 신뢰할 수 있는 비교적 간단한 해석 기술을 제안하였다. The package used to transport radioactive materials, which is called by the shipping cask, must be safe under normal and hypothetical accident conditions. These requirements for the cask design must be verified through test or finite element analysis. Since the cost for FE analysis is less than the one for test, the verification by FE analysis is mainly used. But due to the complexity of mechanical behaviors, the results depend on how users apply the codes and can cause severe errors during analysis. In this paper, finite element analysis is carried out for the 9 meters free drop condition of the hypothetical accident conditions using LS-DYNA3D and ABAQUS/Explicit. We have investigated the analyzing technique lot the free drop impact test of the cask and investigated several vulnerable cases. The analyzed results were compared with each other. We have suggested a reliable and relatively simple analysis technique for the drop test of spent nuclear fuel casks.

충주(忠州)댐 우안(右岸) 산사태(山沙汰)에 관한 연구(硏究)

최영진,송무영,Choi, Young Jin,Song, Moo Young 대한자원환경지질학회 1991 자원환경지질 Vol.24 No.3

Analysis for landslides was studied in framework of Chungju dam right abutment, 6.5km northeast of Chungju city. $5.5{\times}10^6m^3$ landslide materials were excavated during dam construction for safety of the Chungju dam. Geology of study area is composed mainly of meta sediments such as dolomitic limestone, quartzite and schist which are dipping toward the Nam Han river. Scanline survey of discontinuities was performed for slope stability, resistivity exploration was performed for the evaluation of potential failure plane, and direct shear strength test of rocks and soils was performed for the effect on landslide. Monitoring systems of tiltmeter, tensiometer, ground water observation hole and level monument were installed during dam construction and interpreted for the evaluation of slope instability. Kinematic solution of the geological structure and evaluation using safety factor for slope may prove the failure of the slope.

논문편 : 고추씨 기름의 지질성분에 관한 연구

최영진,고영수 ( Yong Jin Choi,Young Su Ko ) 대한가정학회 1990 Human Ecology Research(HER) Vol.28 No.2

Kano 모델을 이용한 화장품 구매의도에 영향을 미치는 마케팅 믹스요인에 관한 연구

최영진,장규순,Choi, Young Jin,Chang, Gyoo Soon 한국벤처창업학회 2014 벤처창업연구 Vol.9 No.6

본 연구는 Kano 모델을 이용하여 화장품 구매에 영향을 미치는 마케팅 믹스 요인을 분석하기 위해, 선행적 연구를 바탕으로 마케팅 믹스 요인 분류에 따라 긍정적 질문과 부정적 질문을 동시에 설문하여 매력적 품질, 일원적 품질, 당연적 품질을 규명하고자 하였다. Timko's Analysis 고객 만족과 불만족 계수를 이용한 화장품 구매에 영향을 미치는 마케팅 믹스 요인을 분석한 결과 촉진전략 중 가격할인 정책과 가족/ 주변인의 추천 전략이 매력적 품질로 나타났다. 제품 전략의 효능과 효과, 사용감, 피부적합성은 일원적 품질로 나와 고객의 요구를 충족시키면 선형적으로 그 만족도가 증가하는 것으로 파악되었다. 반면에 제품 측면의 용기, 포장 디자인, 색상, 브랜드 인지도와, 가격 측면의 낮은 가격, 중간가격 수준과 유통 측면의 구매경로, 촉진 측면의 매체 광고 에 대해서는 무관심 품질로 나타나서 이들 요인에 대하여는 과도한 예산을 집행하는 것은 투입대비 효과가 높지 않을 것으로 판단해 볼 수 있다. This study is to contribute to the policy decision of cosmetic industry through analyzing marketing mix factors which affects customers' buying intention. For this study, marketing mix factors that impact on cosmetic customers purchasing intention were collected and chi-square independence analysis of SPSS and qualitative analysis technology of Kano & Timko were used. Analysis reached one conclusion, which factors were maximizing customers satisfaction, shows the price discount policy and recommendation from family and colleague. Product's effectiveness, usefulness and skin compatibility were rated as an one-dimensional quality as those factors were linearly affected when customers needs were satisfied. However product's containers, package design, colors, brand reputation, low and middle price, distribution channel and advertising medias were investigated as an indifferent quality and they were rated as low satisfaction/dissatisfaction coefficient of Timko. Therefore they do not need to invest to those factors too much budget for attaining customers' buying intention.

금속 Ca증기에 의한 고체 Nd 금속의 탈산

최영진,김상욱,전병서,송창빈,오윤석,이영주,Choi, Yonug-Jin,Kim, Sang-Wuk,Jeon, Byung-Seo,Song, Chang-Bin,Oho, Yoon-Seok,Lee, Young-Joo 한국재료학회 2017 한국재료학회지 Vol.27 No.5

As a basic study for the removal of oxygen in solid Nd metal by metal Ca vapour, by using the thermodynamic data such as ${\Delta}G-T$ diagrams and Nd-O and Nd-Ca equilibrium diagrams, the amount of residual oxygen in solid Nd metal formed based on deoxidation reaction by Ca vapour, instead of by direct contact of solid Nd metal and Ca solution, was determined. Deoxidation experiments were carried out for solid Nd metal in a temperature range of $890{\sim}970^{\circ}C$ for 1h to 4h and content of addition Ca of 0.6~1.8 g (5~15 wt% of solid Nd metal). As a result, it was found that as deoxidation temperature increased, dissolved oxygen decreased. Especially, it was observed that a small amount of Nd-Ca alloy liquid was formed on the surface of the solid Nd metal sample deoxidized at $970^{\circ}C$ for approximately 1 hour. Also, it was found that if the content of addition Ca was 1.8 g (15 wt% of solid Nd metal) the amount of produced Nd-Ca alloy increased slightly. However, for the Nd sample with which the deoxidation reaction was performed at $930^{\circ}C$ for 4h with content of addition of Ca of 1.5 g (13 wt% of Nd metal), the residual oxygen was found to decreased to 12.00 ppm.

대체 감미료를 사용한 Sponge Cake의 특성

최영진,김광옥,Choi, Young-Jin,Kim, Kwang-Ok 한국식품조리과학회 1990 한국식품조리과학회지 Vol.6 No.2

The characteristics of sponge cakes containing sucrose or other sweeteners for diabetes mellitus patients were investigated through physical measurement and sensory evaluation. The results are as follows: The physical properties of cake batters and cakes with sweeteners were different from each other in viscosity, specific gravity, standing height, firmness, and springiness. from the result of sensory evaluation, it was shown that cakes containing sorbitol and fructose had high quality even though they were not as good as cake with sucrose. However, cakes with saccarine and stevioside showed much difference compared with cake with sucrose. The characteristics of sponge cake with combined sweeteners (sorbitol plus stevioside) were compairable to those of sucrose cake. There was little difference in specific gravity. The result of sensory evaluation indicated the combined use of both sweetenes could produce bette cakes than either stevioside or sorbitol. Practical utilization of this cake would be provided under the sensory evaluation on these cakes by diabetes mellitus patients.

BaTi₄O₉계 세라믹스의 저온소결 및 마이크로파 유전특성

최영진,신동순,박재환,남산,박재관,Choi, Young-Jin,Shin, Dong-Soon,Park, Jae-Hwan,Nahm, Sahn,Park, Jae-Gwan 한국세라믹학회 2003 한국세라믹학회지 Vol.40 No.2

저온동시소성 기능성 기판용 소재로 활용하기 위하여 Ba $Ti_4$ $O_{9}$계 마이크로파 유전체에 저융점의 유리 프리트를 첨가하여 저온소성 거동 및 마이크로파 유전특성을 고찰하였다. 유리 프리트의 첨가량이 증가할수록 소결 하한 온도가 낮아졌으며, l0wt%의 유리 프리트를 첨가하였을 때 875$^{\circ}C$의 소성온도에서 상대밀도 98% 이상을 나타내는 충분한 소결이 이루어졌다. 이 때 소결체의 마이크로파 유전특성은 유전율 32, 품질계수 9000 GHz, 공진주파수 온도계수 10 ppm/$^{\circ}C$으로 평가되었다. 유리의 첨가량이 증가하면서 소결 과정에서 주상인 Ba $Ti_4$ $O_{9}$가 Ba $Ti_{5}$ $O_{11}$상과 $Ba_4$ $Ti_{13}$ $O_{30}$상으로의 변화하는 현상도 관찰되었다. Effect of glass addition on the low-temperature sintering and microwave dielectric properties of $BaTi_4O_9$-based ceramics were studied to develop the materials for the functional substrate of low-temperature co-fired ceramics. When 10 wt% of glass was added, sufficient densification was obtained and the relative density more than 98% was reached at the sintering temperature of$875{\circ}C$. The microwave dielectric properties were k=32, Q*f=9000 GHz, ${ au}_f$=10 ppm/${\circ}C$. As the amount of glass increased, phase decompositions from $BaTi_4O_9;to;BaTi_5O_{11};and;Ba_4Ti_{13}O_{30}$ was observed.

Glass 첨가에 의한 BaTi₄O₉계 중유전율 LTCC 유전체의 저온소결 및 상변화 거동

최영진,박재환,남산,박재관,Choi, Young-Jin,Park, Jae-Hwan,Nahm, Sahn,Park, Jae-Gwan 한국세라믹학회 2004 한국세라믹학회지 Vol.41 No.12

[ $BaTi_{4}O_9$ ]계 세라믹스에 borosilicate계 유리 프리트를 첨가할 때 주결정상이 $BaTi_{5}O_{11}$로 변화되는 현상을 XRD와 TEM으로 분석하였다. Borosilicate계 유리 프리트가 $BaTi_{4}O_9$상으로부터 Ba 이온을 선택적으로 흡수함으로써 주상인 $BaTi_{4}O_9$ 상보다 Ti-rich인 $BaTi_{5}O_{11}$상으로 변화하는 것으로 추측하였다. 이와 같은 결과는 유리의 첨가량과 열처리 온도에 따라 영향을 받는데 $BaO-TiO_2$계의 Ti-rich 영역에 속하는 $Ba_{4}Ti_{13}O_{30},\;Ba_{2}Ti_{9}O_{20}$ 등의 결정상도 상변화 과정에 참여하고 있음을 관찰하였다. 중-고유전율 LTCC 조성개발을 위하여 유리 첨가에 의한 중-고유전율 모재료의 저온소결을 시도할 때 적정한 저온소결특성을 확보하면서도 상변화를 고려한 유리 프리트 첨가량 제어가 필요함을 알 수 있었다. The main phase of $BaTi_{4}O_9$-based ceramics was transformed to $BaTi_{5}O_{11}$ caused by the sintering with borosilicate glass, which was analyzed by using XRD and TEM. We considered that the phase change from $BaTi_{4}O_9$-based ceramics to the Ti-rich $BaTi_{5}O_{11}$ phase resulted from borosilicate glass selective absorbing of Ba ions from the $BaTi_{4}O_9$. In these results, we found a dependence on the amounts of the glass frits and the annealing temperature, and the phase change is also dependent of the main phases of $Ba_{4}Ti_{13}O_{30},\;and\;Ba_{2}Ti_{9}O_{20}$, which are involved in the $BaO-TiO_2-based$ Ti-rich region. In the case of sintering of middle- and high- permittivity material with additional glass frits for middle- and high- dielectric coefficients LTCC composition, control of weight fraction of the glass frits accompanying low-temperature sintering property with appropriate phase change is required.