Photoluminescence Imaging of SiO₂@ Y₂O₃:Eu(III) and SiO₂@ Y₂O₃:Tb(III) Core-Shell Nanostructures

Cho, Insu,Kang, Jun-Gill,Sohn, Youngku Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

We uniformly coated Eu(III)- and Tb(III)-doped yttrium oxide onto the surface of $SiO_2$ spheres and then characterized them by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction crystallography and UV-Visible absorption. 2D and 3D photoluminescence image map profiles were reported for the core-shell type structure. Red emission peaks of Eu(III) were observed between 580 to 730 nm and assigned to $^5D_0{\rightarrow}^7F_J$ (J = 0 - 4) transitions. The green emission peaks of Tb(III) between 450 and 650 nm were attributed to the $^5D_4{\rightarrow}^7F_J$ (J = 6, 5, 4, 3) transitions. For annealed samples, Eu(III) ions were embedded at a $C_2$ symmetry site in $Y_2O_3$, which was accompanied by an increase in luminescence intensity and redness, while Tb(III) was changed to Tb(IV), which resulted in no green emission.

Photoluminescence Imaging of SiO2@Y2O3:Eu(III) and SiO2@Y2O3:Tb(III) Core-Shell Nanostructures

Insu Cho,Jun-Gill Kang,손영구 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.2

We uniformly coated Eu(III)- and Tb(III)-doped yttrium oxide onto the surface of SiO 2 spheres and then characterized them by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction crystallography and UV-Visible absorption. 2D and 3D photoluminescence image map profiles were reported for the core-shell type structure. Red emission peaks of Eu(III) were observed between 580 to 730 nm and assigned to 5 D 0 → 7 F J (J = 0 – 4) transitions. The green emission peaks of Tb(III) between 450 and 650 nm were attributed to the 5 D 4 → 7 F J (J = 6, 5, 4, 3) transitions. For annealed samples, Eu(III) ions were embedded at a C 2 symmetry site in Y 2 O 3 , which was accompanied by an increase in luminescence intensity and redness, while Tb(III) was changed to Tb(IV), which resulted in no green emission.

Photoluminescence profile imaging of Eu(III), Tb(III) and Eu(III)/Tb(III)-doped yttrium oxide nanosheets and nanorods

Cho, Insu,Kang, Jun-Gill,Sohn, Youngku Elsevier 2015 Journal of luminescence Vol.157 No.-

<P><B>Abstract</B></P> <P>Eu(III), Tb(III) and Eu(III)/Tb(III)-doped Y<SUB>2</SUB>O<SUB>3</SUB> nanosheets and nanorods were prepared by hydrothermal synthesis and post-thermal treatment. Their morphology, crystallinity, photoluminescence and UV–visible absorption profiles were fully examined by scanning electron microscopy (SEM), X-ray diffraction (XRD) crystallography, photoluminescence imaging and UV–vis absorption spectroscopy. The as-prepared samples commonly showed the crystal structure of Y<SUB>4</SUB>O(OH)<SUB>9</SUB>NO<SUB>3</SUB>, which crystallized to cubic phase Y<SUB>2</SUB>O<SUB>3</SUB> after 550°C-thermal annealing. The sharp emissions of Eu(III) between 580 and 720nm were attributed to <SUP>5</SUP>D<SUB>0</SUB>→<SUP>7</SUP>F<SUB>J</SUB> (<I>J</I>=0,1,2,3,4) transitions, and those of Tb(III) between 450 and 720nm were attributed to <SUP>5</SUP>D<SUB>4</SUB>→<SUP>7</SUP>F<SUB> <I>J</I> </SUB> (<I>J</I>=6,5,4,3) transitions. Energy transfer from Tb(III) to Eu(III) was confirmed by the photoluminescence decay dynamics. In the cubic Y<SUB>2</SUB>O<SUB>3</SUB> structure, Eu(III) was embedded at the C<SUB>2</SUB> symmetry site and dominated by the <SUP>5</SUP>D<SUB>0</SUB>→<SUP>7</SUP>F<SUB>2</SUB> transition. Conversely, Tb(III) was oxidized to non-luminescent Tb(IV) in the cubic structure.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Eu(III), Tb(III)-doped and codoped Y complex nanorods and nanosheets prepared by a hydrothermal method. </LI> <LI> Eu(III), Tb(III)-doped and codoped Y<SUB>2</SUB>O<SUB>3</SUB> nanorods and nanosheets prepared by a post-annealing method. </LI> <LI> Photoluminescence imaging profiles were fully obtained. </LI> <LI> Tb(III) oxidized to Tb(IV) upon thermal annealing in cubic Y<SUB>2</SUB>O<SUB>3</SUB> matrix. </LI> </UL> </P>

Exploration of Optimal Product Innovation Strategy Using Decision Tree Analysis

Insu Cho 과학기술정책연구원 2017 STI Policy Review Vol.8 No.2

Recently, global competition in the manufacturing sector is driving firms in the manufacturing sector to conduct product innovation projects to maintain their competitive edge. The key points of product innovation projects are 1) what the purpose of the project is and 2) what expected results in the target market can be achieved by implementing the innovation. Therefore, this study focuses on the performance of innovation projects with a business viewpoint. In this respect, this study proposes the “achievement rate” of product innovation projects as a measurement of project performance. Then, this study finds the best strategies from various innovation activities to optimize the achievement rate of product innovation projects. There are three major innovation activities for the projects, including three types of R&D activities: Internal, joint and external R&D, and five types of non-R&D activities ─ acquisition of machines, equipment and software, purchasing external knowledge, job education and training, market research and design. This study applies decision tree modeling, a kind of data-mining methodology, to explore effective innovation activities. This study employs the data from the ‘Korean Innovation Survey (KIS) 2014: Manufacturing Sector.’ The KIS 2014 gathered information about innovation activities in the manufacturing sector over three years (2011-2013). This study gives some practical implication for managing the activities. First, innovation activities that increased the achievement rate of product diversification projects included a combination of market research, new product design, and job training. Second, our results show that a combination of internal R&D, job training and training, and market research increases the project achievement most for the replacement of outdated products. Third, new market creation or extension of market share indicates that launching replacement products and continuously upgrading products are most important.

하이브리드차량의 구동모터 속도에 따른 SOC 특성 연구

조인수(Insu Cho),박준하(Junha Park),이진욱(Jinwook Lee) 한국자동차공학회 2019 한국자동차공학회 부문종합 학술대회 Vol.2019 No.5

지식활동성과 향상을 위한 지식공유의 영향요인에 대한 연구

조인수(Insu Cho),박희준(Heejun Park) 한국전자거래학회 2008 한국전자거래학회 심포지움 및 기타간행물 Vol.- No.-

본 연구는 관계중심적 지식관의 관점에서 지식공유의 영향 요인을 파악하고, 이 요인들이 실제로 지식공유에 긍정적인 영향을 미쳐서 지식성과활동을 향상 시키는지 알아보고자 한다. 독립변수인 관계적 요인은 신뢰, 개방적 의사소통, 협동으로 설정하였고, 지식공유의 영향을 받는 종속 변수인 지식활동성과는 지식품질과 지식경영사용자만족도로 설정하였다. 본 연구를 통해 조직경쟁력 향상을 위해서는 지식뿐만 아니라 그것을 사용하는 사람 및 주변 환경까지 관리할 필요가 있음을 제안한다. This study finds out the influence factor of knowledge sharing based on the viewpoint of the relationship central knowledge and inquires out the relationship between knowledge sharing and a knowledge activity performance. The related factor is set trust, openness communication and cooperation as independent variables. And the knowledge activity performance is set knowledge quality and user knowledge satisfaction as dependent variables which are influenced by knowledge sharing. This study proposes that to improve the organizational performance needs to manage not only knowledge, but also the users and surroundings.

UDS 보안 테스팅을 위한 세션 및 서비스 스캐너 구현

조인수(Insu Cho),윤진영(Jin-yeong Yoon),엄성욱(Sung-wook Eom) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

UDS is an international standard protocol for integrated diagnostic services in ECUs and provides powerful functions for vehicle diagnostics. If the security of the UDS diagnosis is compromised and abused, the integrity, confidentiality and availability of the ECU can be seriously affected. This paper aims to implement a scanner to efficiently identify unintended mistakes of developers or custom functions implemented for developer convenience when implementing UDS functions of ECU. The implemented scanner proceeds in the order of session discovery, service discovery, and subfunction discovery. After searching the session information implemented in the ECU using the DFS algorithm, the service and sub function for each session are scanned based on the derived session information. The existence of sessions and services is determined based on the NRC defined in the UDS. As a result of testing the scanner implemented for a specific ECU, 0x05, 0x10 custom sessions and 0x12, 0x20 custom services were found. The scanner presented in this paper scans using only three response cases, but we plan to implement a scanner that provides a wider range of scans through research on specific test methodologies for each service and test methodologies for custom sessions/services in the future.

압축착화 연소방식에서 Cam-in-Cam 가변밸브 제어전략별 NOx저감 특성 해석

조인수(Insu Cho),이유민(Yumin Lee),이재문(Jeamoonng Lee),이진욱(Jinwook Lee) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6

유비쿼터스 서비스 모델 및 분류체계에 관한 연구 : GIS(Geographic Information System) 산업을 중심으로

조인수(Cho, Insu),박희준(Park, Heejun),원종태(Won, Jong-Tae) 한국IT서비스학회 2009 한국IT서비스학회 학술대회 논문집 Vol.2009 No.1

본 연구는 유비쿼터스 환경에서의 체계적 서비스를 도출하기 위한 분류체계를 제안하고 이를 유비쿼터스 기반 GIS 서비스에 적용시켜 그 결과를 분석하고 시사점을 도출한다. 이를 위해 기술적 특성과 고객 니즈의 특성을 포함한 유비쿼터스 환경과 서비스 속성을 조사한다. 또한 기존의 제시되었던 u-서비스 분류체계를 분석하고 GIS 산업의 가치사슬과 기술 및 서비스 동향을 조사하여 새로운 유비쿼터스 서비스 분류 체계를 개발하는데 활용한다. 개발된 유비쿼터스 서비스 분류체계를 검증하기 위해 유비쿼터스 기반 GIS 서비스의 도입 사례를 조사하여 적용해본다. 적용 결과를 통해 분류 체계의 적합성을 검증하고 향후 GIS 서비스 도입 시 고려해야 할 사항과 발전방안을 제시한다.

바이패스 방식 피에조 인젝터의 피에조 적층 및 인가전압에 따른 연료분사 특성 연구

조인수 ( Insu Cho ),김우택 ( Wootaek Kim ),이진욱 ( Jinwook Lee ) 한국액체미립화학회 2020 한국액체미립화학회지 Vol.25 No.1

In the common rail fuel injection system, which is the core of diesel high efficiency and NOX reduction, injection strategies such as high pressure injection of fuel, accurate injection rate control, and multistage injection are important to increase fuel atomization. In this study, the bypass type piezo injector for the electronic control based common rail injection system applied to diesel fuel vehicle was studied. In particular, the injection rate and internal fuel flow characteristics of the high-pressure injector according to the piezo stacking number and applied voltage were analyzed by theoretical numerical method. When the applied voltage changes, it is determined that additional fuel flow through the bypass compensates for the reduced valve driving force due to the change in the driving voltage.