http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ultraprecision machining based micro-hybrid lens fabrication for scanning device
Dongyoon Yoo,Dong-Ho Lee,Sun-Kyu Lee 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10
In this research, refractive-diffractive hybrid design is proposed for micro-lens used in optical scanning system. For refractive design of the lens, optimization method with reducing transverse ray aberration is used for target focal length with minimized aberration. Diffractive efficiency considering depth and period of Fresnel edge pattern is calculated by RCWA, and then the proper depth and minimum period of the Fresnel edge pattern can be determined for high efficiency. In the lens geometry, machining limit of V-shaped diamond tool must be applied, because the tool determines limit of the micro-pattern size and possibility of the machining so that it determines the whole size of the lens. With the process, the refractive lens can be optimized for 300 μm focal length and minimum aberration, the depth of Fresnel edge is determined to 0.94 μm by the diffractive design of PMMA (index 1.4985) lens, and also the 4985) lens, and also the is determined to 423.4 μm when considering machining limit. This designed lens is fabricated by 5-axis ultraprecision machine with nanometer resolution for low surface roughness. Then, the lens is imprinted by hot embossing process. The result of measuring focal length is 336 μm and NA is calculated to 0.63. Also, imaging test of the lens is investigated, and the lens can be used in optical scanning system by the result.
Yoo Hyunjin,Choi Dongyoon,Choi Youngsok 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.4
Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]). Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis. Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation. Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals. Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]).Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis.Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation.Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals.
리튬폴리머 배터리(LiPB)의 OCV를 이용한 배터리 SOH 추정 방법
노동윤(Dongyoon Noh),황인성(Insung Hwang),유지윤(Jiyoon Yoo) 전력전자학회 2010 전력전자학술대회 논문집 Vol.2010 No.7
본 논문은 리튬 폴리머 배터리(LiPB)의 OCV(Open Circuit Voltage;개방전압)를 이용한 배터리 SOH(State Of Health;잔존수명) 추정하는 방법의 제안이다. 종래에는 배터리 수명은 제조회사에서 지정된 시간이나 충방전 횟수를 기초로 수명을 결정하였다. 하지만 배터리의 온도, 충전방법, 전류변화 및 DOD(Depth of Discharge;방전심도) 정도에 따라 배터리 수명은 유동적이다. 따라서 배터리가 노후됨에 따라 OCV가 변한다는 원리를 이용하여 임피던스 분석을 통해서 SOH, 즉 배터리 잔존수명을 추정하는 기술을 제안하였다.
전기자동차용 차량 탑재형 충전기의 수명과 발열을 고려한 링크 캐패시터 설계방법
노동윤(Dongyoon Noh),유석정(Seokjeong Yoo),강재준(Jaejun Kang),문형태(Hyungtae Moon) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11
Using fossil fuels (oil, coal, natural gas), air pollution by exhaust gases has been prominent as a serious social issue. In particular, the recent automobile transportation accounted for more than 95%, it cause the global warming and acid rains. Applies in developed countries such as the United states, Europe, investment for eco-friendly cars, including the stringent emissions regulations with HEV(Hybrid Electric Vehicle), EV(Electric Vehicle), FCEV(Fuel Cell Electric Vehicle) is made. Electric Vehicle operates by battery power instead of an internal combustion engine. To charge the battery, It is necessary to On-board charger (OBC). In particular, the size and stability and service life should be considered, and it is essential to the high power density and a long life-time. Generally, OBC consists of two configurations (PFC, DC/DC converter). A PFC stage is for power factor correction and DC/DC converter is for isolation and charging. In order to minimize the loss, the link capacitor is used a high-voltage capacitor and power density capacitors, high voltage electrolytic capacitor. However, a life-cycle of electrolytic capacitor depends on ripple current, ambient temperature and etc. So, in this paper, the charger for long life electrolytic capacitors for high-voltage link capacitor of the optimal design method is proposed.
황인성(Insung Hwang),노동윤(Dongyoon Noh),유지윤(Jiyoon Yoo) 대한전기학회 2010 대한전기학회 학술대회 논문집 Vol.2010 No.4
태양광 발전 시스템에서 발전 효율 향상을 위해 태양전지 어레이의 집광 각도 제어가 필수적 인데 집광 각도 제어 방식에는 광센서에 의한 추적 방식과 천문학적 추적 방식이 사용되고 있다. 본 논문에서는 영상처리를 이용한 광 추적 방식 알고리즘을 제안하며 천문학적 추적방식과 광센서 추적 방식을 혼용 하여 사용할 경우 날씨정보를 이용하여 운영 하는 방법을 제안한다.
열 하중 기반의 리츠벡터와 순차적 센서위치 선택방법을 이용한 강건하고 효율적인 열 오차 모델링
현재엽(Jaeyub Hyun),유동윤(Dongyoon Yoo),이선규(Sun-Kyu Lee),왕세명(Semyung Wang) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10
Thermal deformations are among the most significant factors to errors generation of machine tool, this degrades the performance and accuracy of the machine tool. There are many methods to reduce the thermal deformation, such as structural designs to minimize thermal deformation, approaches to block and/or suppress thermal source, and thermal error compensation techniques to estimate and control thermal deformation. Among these, thermal error compensation techniques have been realized as the most successful method and actively studied. Securing of robustness and effectiveness of the thermal error modeling is directly correlated to the better compensation results. Most of the current thermal error modeling methods is highly dependent on measured data, and cannot consider mechanisms of the thermal deformation due to the thermal-structural interaction effect. In this paper, therefore, a novel and innovative strategy that can select the optimized thermal sensor placement and thermal error modeling method are proposed based on thermal load dependent ritz vectors. Operation state of the actual machine tool and thermal source variation are continuously changing according to the time. Thus, the various boundary conditions are applied to properly deal with these variations. The Wilson’s Ritz algorithm is used for generating the thermal load dependent Ritz vectors. Finally, for various 2D and 3D systems such as heat pipe and spindle, both existing thermal errors modeling method to use the eigenvectors and proposed method to use thermal load dependent ritz vectors are compared and investigated. Through this, the robustness and effectiveness are verified.