LP-MOCVD법으로 합성된 ZnO 나노선의 구조 및 광학적 특성

최영진,박재환,박재관,Choi, Young-Jin,Park, Jae-Hwan,Park, Jae-Gwan 한국결정학회 2006 韓國結晶學會誌 Vol.17 No.1

MOCVD 공정방법에 의해 수직정렬된 ZnO 나노선을 합성하고 공정조건 제어에 의해 합성되는 나노선의 물리적, 광학적 특성이 어떻게 변화하는지를 고찰하고자 하였다. 온도 및 산소분압제어 등의 공전변수 제어를 통하여 ZnO 나노 구조체는 나노선, 나노로드 뿐만 아니라 나노바늘 (nano-needle) 등 다양한 구조로 변화되었으며 그 직경 및 길이도 제어가 가능하였다. 전체적으로 양호한 특성의 wurzite 구조를 나타내었으며 기판에 수직인 방향으로 [0001] 방향으로 성장하였다. 광학특성에서는 나노선 직경이 작아질수록 주방출 피크의 천이현상이 관찰되었다.

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.

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.

리튬이온전지용 산화갈륨 (β-Ga₂O₃) 나노로드 (Nanorods) 음극 활물질의 물리적.전기화학적 특성

최영진,류호석,조규봉,조권구,류광선,김기원,Choi, Young-Jin,Ryu, Ho-Suk,Cho, Gyu-Bon,Cho, Kwon-Koo,Ryu, Kwang-Sun,Kim, Ki-Won 한국전기화학회 2009 한국전기화학회지 Vol.12 No.2

고순도의 $\beta-Ga_{2}O_{3}$ 나노로드(nanorods)가 니켈산화물 나노입자를 촉매로 사용하고 갈륨금속분말을 원료물질로 이용하여 화학기상증착법으로 합성되었다. 전계방출형 주사전자현미경을 이용하여 $\beta-Ga_{2}O_{3}$ 나노로드를 관찰한 결과, 평균직경은 약 160 nm 그리고 평균길이는 $4{\mu}m$였으며 vaporsolid(VS) 성장기구를 통하여 성장되었음을 알 수 있었다. X-선 회절시험과 고분해능 투과전자 현미경을 이용한 결정구조 분석 결과, 합성된 나노로드의 내부는 단사정계 결정구조를 가지는 단결정의 $\beta-Ga_{2}O_{3}$로 이루어져 있고 외벽은 비정질 갈륨옥사이드로 이루어진 코어-셀 구조로 구성되어 있는 것을 확인하였다. 합성된 $\beta-Ga_{2}O_{3}$ 나노로드를 음극 활물질로 사용하여 전극을 제조하고 전기화학적 특성을 분석한 결과, 리튬/$\beta-Ga_{2}O_{3}$ 나노로드 전지는 첫 방전 시 867 mAh/g-$\beta-Ga_{2}O_{3}$의 높은 용량을 나타내었으나 초기 비가역 용량으로 인해 62%의 낮은 충 방전 효율을 나타내었다. 그러나 5 사이클 이후 높은 충 방전 효율을 보이며 30 사이클까지 안정된 사이클 특성을 나타내었다. $\beta-Ga_{2}O_{3}$ nanorods were synthesized by chemical vapor deposition method using nickel-oxide nanoparticle as a catalyst and gallium metal powder as a source material. The average diameter of nanorods was around 160 nm and the average length was $4{\mu}m$. Also, we confirmed that the synthesis of nanorods follows the vapor-solid growth mechanism. From the results of X-ray diffraction and HR-TEM observation, it can be found that the synthesized nanorods consisted of a typical core-shell structure with single-crystalline $\beta-Ga_{2}O_{3}$ core with a monoclinic crystal structure and an outer amorphous gallium oxide layer. Li/$\beta-Ga_{2}O_{3}$ nanorods cell delivered capacity of 867 mAh/g-$\beta-Ga_{2}O_{3}$ at first discharge. Although the Li/$\beta-Ga_{2}O_{3}$ nanorods cell showed low coulombic efficiency at first cycle, the cell exhibited stable cycle life property after fifth cycle.

미래 식량자원으로써 장수풍뎅이 유충의 영양학적 평가

최영진,범미기,김은경,이슬비,황연현,장영호,배성문,Choi, Young-Jin,Fan, Meiqi,Kim, Eun-Kyung,Lee, Seul-bi,Hwang, Yeon-hyeon,Jang, Yeong-Ho,Bae, Sung-Mun 한국식품과학회 2020 한국식품과학회지 Vol.52 No.6

식용 곤충은 인구증가에 따른 식량 문제를 해결하기 위한 하나의 방법으로 제시되며 최근 곤충의 생리활성 기능과 관련한 연구가 많이 수행되고 있다. 반면 식품으로서 활용 가능한 기초연구는 부족한 실정으로 본 연구에서 장수풍뎅이 유충의 단백질 대체 자원으로서 영양학적 기능을 규명하기 위한 실험을 실시하여 장수풍뎅이 유충 단백질(ADP)의 식이 효율, 단백질 효율, 순 소화율 등을 동물실험을 통해 알아보았다. 4주령 SD-rat 24마리를 이용하여 각 그룹 당 8마리 3그룹으로 실험을 실시하였다. 실험군은 사료 내 전체 kcal 20%가 Casein 단백질로 구성된 사료를 식이 하는 일반 식이군(Con), 전체 kcal 20%가 장수풍뎅이 유충의 단백질로 구성된 사료를 식이 하는 장수풍뎅이 유충 단백질식이군(ADP), 그리고 체내 대사작용에 의해 배설되는 단백질(metabolic fecal nitrogen)을 측정하기 위하여 단백질 무 첨가 식이군(NP, non-protein diet)으로 설정했다. 4주간 식이를 공급하여 장수풍뎅이 유충 단백질의 식이 효율(Food Efficiency Ratio, FER), 단백질 효율(Protein Efficiency Ratio, PER), 순 소화율(true digestibility, TD)을 평가했다. 본 실험 결과 식이 효율은 Con군에서 0.52, 장수풍뎅이 유충 단백질 섭취군에서 0.41로 ADP에서 유의적으로 낮은 수준을 보였다. 단백질 효율은 ADP군에서 2.39, Con군에서 2.63으로 ADP군은 Con군에 비해 낮았으나 유의적인 차이는 없었다. 순 소화율은 Con군에서 91%, ADP군에서 80%로 나타났으며 통계적인 유의적 차이는 없었다. 장수풍뎅이 유충의 순 소화율은 80%로 나타났으며 콩과류의 단백질 순 소화율 64-77%에 비해 높은 수준을 보였다. Edible insects might be used as a means to solve food insecurity caused by population growth. Many studies have investigated the biological activity of insects; however, few studies have investigated the nutritional value of insects. Therefore, the aim of this study was to investigate the nutritional value of Allomyrina dichotoma larva protein (ADP) as a source of protein replacement. In vivo studies were conducted to determine the food efficiency ratio (FER), protein efficiency ratio (PER), and true digestibility (TD) of ADP. Experiments were conducted in 3 groups of 8 animals per group using twenty-four 4-week-old SD rats. The experimental groups included the general diet group (Con), in which 20% of the total Kcal in the diet was composed of casein protein, and the ADP group (ADP), in which 20% of the total Kcal was composed of ADP protein, and a non-protein diet group (NP) to measure the protein (metabolic fecal nitrogen) excreted by metabolic processes in the body. As a result of this experiment, we found that the FERs were 0.52 and 0.41 in the casein protein intake (Con) and ADP groups, respectively, thus showing a significantly lower level in the ADP group. The PERs of ADP and Con were 2.39 and 2.63, respectively. The TD of Con and ADP were 91% and 80%, respectively.

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.

구강점막 상피세포에 대한 치과 주조용 비귀금속 합금의 세포독성

최영진,육종인,정문규,Choi, Young-Jin,Yook, Jong-In,Chung, Moon-Kyu 대한치과보철학회 1999 대한치과보철학회지 Vol.37 No.6

Although many studies on the cytotoxicity of the dental cast base metal alloys and their components have been carried out, the results are rather conflicting because of the different type of cells used and the various experimental procedures taken. Recently a number of scientists have claimed that it would be preferable to focus on the use of cells from relevant specific location of the human bodies. Consequently, the primary cultured oral keratinocyte derived from oral mucous along with nickel chloride and several of widely used dental cast base metal alloys(two Ni-Cr alloys and one Co-Cr alloy)in domestic were selected for this study, from which 1) The amounts of released metal ions were determined using atomic absorption spectrometry, 2) The cytotoxicity of nickel chloride and dental cast base metal alloys was evaluated via MTT assay, and finally, 3) The amounts of released metal ions and the cytotoxicity of nickel chloride were correlated with the cytotoxicity of dental cast base metal alloys And, the results were summarized as follows; 1. Nickel ion from Ni-Cr alloys and Cobalt ion from Co-Cr alloys resulted in maximum releasing rate during first 2h hours, followed by a decrease in releasing rate with time. Chromium ion were found to be minimal in all alloys. 2. In cytotoxic test. with $40{\mu}M,\;80{\mu}M$ of nickel chloride, there were observed an increase in the relative cell number compared to control samples after 24 hours. With $160{\mu}M$, there was found to be no difference in the relative cell number with control, except that 48 hour showed a increase in relative cell number. With $320{\mu}M$, the relative cell number remained constant and decreased after 48 hours, and with $640{\mu}M$, a continuing decrease in relative cell number was observed throughout test period. 3 The sensitivity of primary cultured oral epithelium to nickel was lower compared to the cells used in other studies. 4. CB-80 Soft and Regalloy showed no cytotoxicity to primary cultured oral epithelium and New crown resulted in a slight cytotoxicity. In conclusion, it was shown that the primary cultured oral keratinocytes could be applied successfully as testing cells in cytotoxicity test. Futhermore, the dental cast base metal alloys used in this study were found to be biocompatible.

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.

개인정보 보호 분야 공동규제의 성공요인과 발전방향에 관한 연구

최영진,Young Jin Choi 한국IT서비스학회 2023 한국IT서비스학회지 Vol.22 No.5

The Personal Information Protection Commission has been promoting the adoption of co-regulation to replace/improve the existing self-regulation programs since 2022. While the Commission's co-regulation framework has received positive feedback for its contribution to address the regulatory issues, it has also faced criticism for being seen as "co-regulation in appearance only without any real differentiation from existing self-regulation." This study aims to examine the case of industry-specific co-regulation proposed by the Personal Information Protection Commission, with the objectives of 1) determining whether their approach can be categorized as a type of co-regulation with differentiation from the existing self-regulation programs, and 2) proposing improvements for successful regulation. The 'co-regulation' of the Commission can be classified as a form of co-regulation that differs with traditional self-regulation, as it involves government and private organizations collaborating to establish self regulatory codes reflecting industry-specific characteristics as well as provides interest groups with incentives to comply with the codes. The co-regulation framework is evaluated to some extent as successful, but there is still room for improvement in three major aspects. (1) When selecting the areas for co-regulation, a focus should be placed on areas where technological changes are rapid, and government regulations should be applied in areas where they are not. (2) It is necessary to enhance the expertise of regulatory agencies, and (3) ensuring the democratic nature of regulation, such as encouraging the participation of civil organizations, is necessary.