알루미늄 사형주조에서 기공 결함 감소를 위한 연구

이동연,이춘규,Lee, Dong-Youn,Lee, Chun-Kyu 한국금형공학회 2020 한국금형공학회지 Vol.14 No.4

In this study attempted to prevent defects due to blow holes among defects of sand casting products. It was intended to reduce the defect rate by reducing the blow hole of the inner surface. Currently, expectations and requirements for the quality level of non-ferrous aluminum casting in the casting industry are increasing. In addition, the shape is complex and the shrinkage precision is required. Among them, the test prototype is expensive to manufacture the mold, and the production time is also long, and the product is manufactured by sand casting. At this time, the highest defect rates are defects caused by shrinkage defects, surface defects, and blow holes.. At this study, the manufacturing time was shortened by using the shape of the fluid movement path in advance. Also, it is possible to reduce defects due to blow holes.

Disturbed Osteoblastic Differentiation of Fibrous Hamartoma Cell from Congenital Pseudarthrosis of the Tibia Associated with Neurofi bromatosis Type I

이동연,조태준,Hye Ran Lee,이강,Hyuk Joo Moon,박문석,유원준,정진엽,최인호 대한정형외과학회 2011 Clinics in Orthopedic Surgery Vol.3 No.3

Background: Fibrous hamartoma is the key pathology of congenital pseudarthrosis of the tibia (CPT), which was shown to havelow osteogenicity and high osteoclastogenicity. This study further investigated the mechanism of impaired osteoblastic differentiationof fi brous hamartoma cells. Methods: Fibroblast-like cells were obtained from enzymatically dissociated fi brous hamartomas of 11 patients with CPT associatedwith neurofi bromatosis type I (NF1). Periosteal cells were also obtained from the distal tibial periosteum of 3 patientswithout CPT or NF1 as control. The mRNA levels of Wnt ligands and their canonical receptors, such as Lrp5 and β-catenin, wereassayed using reverse transcriptase PCR (RT-PCR). Changes in mRNA expression of osteoblast marker genes by rhBMP2 treatmentwere assayed using quantitative real time RT-PCR. Changes in mRNA expression of transcription factors specifi cally involved inosteoblastic differentiation by rhBMP2 treatment was also assayed using quantitative real-time RT-PCR. Results: Wnt1 and Wnt3a mRNA expression was lower in fi brous hamartoma than in tibial periosteal cells, but their canonicalreceptors did not show signifi cant difference. Response of osteoblastic marker gene expression to rhBMP2 treatment showedpatient-to-patient variability. Col1a1 mRNA expression was up-regulated in most fi brous hamartoma tissues, osteocalcin was upregulatedin a small number of patients, and ALP expression was down-regulated in most fi brous hamartoma tissues. Changes inmRNA expression of the transcription factors in response to rhBMP2 also showed factor-to-factor and patient-to-patient variability. Dlx5 was consistently up-regulated by rhBMP2 treatment in all fi brous hamartoma tissues tested. Msx2 expression was downregulatedby rhBMP2 in most cases but by lesser extent than control tissue. Runx2 expression was up-regulated in 8 out of 18fi brous hamartoma tissues tested. Osterix expression was up-regulated in 2 and down-regulated in 3 fi brous hamartoma tissues. Conclusions: Congenital pseudarthrosis of the tibia appears to be caused by fi brous hamartoma originating from aberrant growthof Nf1 haploinsuffi cient periosteal cells, which failed in terminal osteoblastic differentiation and arrested at a certain stage of thisprocess. This pathomechanism of CPT should be targeted in the development of novel therapeutic biologic intervention.

항공기 탑재 AESA 레이다의 통합 항법 성능 분석 연구

이동연(Dong-Yeon Lee),권혁준(Hyeokjoon Kwon),이동욱(Donguk Lee),이해민(Haemin Lee),정영광(Youngkwang Jung),정재현(Jaehyeon Jeong),박상규(Sanggyu Park),이성원(Sungwon Lee),박준현(June Hyune Park),탁민제(Min-Jea Tahk),방효충(Hyochoong 한국항공우주학회 2021 韓國航空宇宙學會誌 Vol.49 No.4

기존 레이다 시스템에 비해 다양한 이점을 제공하는 능동 위상 배열 (AESA) 레이다의 성공적인 운용을 위해서는 정확하고 강건한 항법이 중요하다. 본 논문은 AESA 레이다를 탑재한 항공기의 EGI 시스템을 기반으로 한 통합 항법의 성능 분석에 대한 연구를 소개한다. GPS 및 IMU 입력을 생성하는 모델이 개발되었고, GPS/IMU 약결합 항법 필터가 구성되었다. GPS/IMU 모델 및 항법필터와 함께 6자유도 항공기 시뮬레이터를 사용하여 항법 성능을 평가하는 절차가 소개되었다. 성능 분석 절차의 단계는 사례 연구와 함께 설명되었다. For successful operations of an airborne Active Electronically-Scanned Array (AESA) radar, which has various advantages over traditional radar systems, accurate and robust navigation is critical. This paper discusses a study on the performance analysis of an integrated navigation based on the Embedded GPS/INS (EGI) system for an aircraft equipped with an AESA radar. The models for generating the inputs for the GPS/IMU are developed. A navigation filter for a loosely-coupled GPS/IMU system is constructed. Overall navigation performance assessment procedure using a six degree of freedom aircraft simulator – along with the GPS/IMU models and the navigation filter – is introduced. The steps of the performance analysis procedure are explained using a comprehensive case study.

모바일 숨바꼭질 게임을 위한 게임공간의 설계

이동연(Dong-Yeon Lee),전병하(Byung-Ha Jun),이준영(Jun-yeong Lee),이부형(Boo-Hyeong Lee) 한국정보기술학회 2022 Proceedings of KIIT Conference Vol.2022 No.12

열화상 데이터를 이용한 철도차량 이상 탐지

이오연(OhYeon Lee),진정민(JeongMin Jin),이호원(Howon Lee),홍성현(SeongHyeon Hong),이재원(JaeWon Lee),조해창(HaChang Cho),김철수(ChulSu Kim),곽영규(YoungGyu Kwak),이동연(Dongyeon Lee) 한국정보과학회 2022 한국정보과학회 학술발표논문집 Vol.2022 No.12

한국예술학의 새로운 연구방법론 모색: 문화연구와의 만남을 통하여

이동연 ( Dong Yeun Lee ) 세계음악학회 2010 음악과 문화 Vol.22 No.-

How does the theoretical practice possible when Korean arts theory meets cultural studies? Encountering of Korean arts theory with cultural studies, with their different academic tradition and methodology to study, is not only most suitable case to meet with the age of convergence of academics but also has productive meaning in broadening their intellectual practices. It has rather interactive system of references for the progressive transformation of their own. In fact, Korean arts theory, with its apparent object for studying and wide field of academy, does not have unique identity from historical studies to meta theory. It has obvious object of Korean traditional arts, thoughts, aesthetics, but it needs time to discuss authentically in what methodology we have to study it. Cultural studies will propose a proper clue to overcome the methodological limitations of Korean arts theory. The methodology of cultural studies basically has the point to interdisciplinary and ethnography. This article aims to inquire how the cultural studies may intervene the transformation of Korean arts theory. The intervention of cultural studies as "methodology" to transform of it conforms the post-colonial practices of cultural studies. It has multiple methodologies such as discourse theory, semiotics, psychoanalysis, post-colonialism, and ethnography. Cultural studies as methodology contributes to the theoretical reconstruction, application to new modes of studies, and the future-oriented design of curriculum towards the transformation of Korean arts theory.

의료용 선형가속기 차폐 재질로써 일반 콘크리트와 저 방사화 콘크리트 비교

이동연 ( Dong Yeon Lee ),김정훈 ( Jung Hoon Kim ) 한국방사선학회 2019 한국방사선학회 논문지 Vol.13 No.1

본 연구는 의료용 선형가속기 시설을 차폐하는 콘크리트에 대한 중성자 방사화 연구로써, 일반 콘크리트와 저 방사화 콘크리트를 비교 분석하였다. 실험 방법은 MCNPX (Ver. 2.5.0)와 FISPACT-2010를 사용하여 모의실험을 진행하여, 광자선과 중성자선에 대한 차폐능을 산정하고 중성자 방사화 평가를 진행하였다. 그 결과 차폐능은 일반 콘크리트에서 20~50 ㎝ 효율적이였으며, 방사화 평가의 경우 저 방사화 콘크리트에서 방사능이 낮게 계산되었으나, 모두 자체처분허용 농도를 초과하지 않는 수준으로 산정되었다. 이를 종합적으로 분석한 결과 일반 콘크리트를 사용하는 것이 효율적인 것으로 판단된다. This study is a neutron activation for concrete that shields medical linear accelerator facilities. Comparison of general concrete and low activation concrete. The simulation method was simulated using MCNPX (Ver. 2.5.0) and FISPACT-2010, and the shielding ability for photon and neutron beams was calculated and neutron activation evaluation was carried out. As a result, the shielding capacity was 20 ~ 50 ㎝ efficient in general concrete, and activate evaluation in low activation concrete was calculated to be low in radioactivity concrete, but all were estimated to not exceed their own allowable concentration in self - disposal. As a result of the comprehensive analysis, it is considered effective to use ordinary concrete.

MCNPX 프로그램을 통한 일반 X선 검사 시 검사실 내 공간선량분포

이동연(Dong-yeon Lee),이진수(Jin-soo Lee) 한국콘텐츠학회 2015 한국콘텐츠학회논문지 Vol.15 No.11

본 연구는 진단용 X선 검사 시 사용하고 있는 부가필터의 재질(Cu, Ni, CaWO4, Gd+Ba)을 다양화하여 그에 따른 검사실 내의 공간선량을 평가 한 후 적합한 재질을 찾아 제시하고자 하였다. 실험은 몬테칼로 기법을 바탕으로 하는 MCNPX 프로그램을 사용하여 흉부와 복부검사를 선택하여 모의실험을 진행하였다. 그 결과 각 재질별 선량은 모의피폭체가 위치한 곳을 중심으로 반경 50 ㎝ 인 지점의 평균 산란선량은 모의피폭체 표면선량의 약 62%, 반경 100 ㎝인 지점은 평균 약 47% 정도 측정되었다. 결과에 따라 현재 상용화 되어 있는 Al 재질을 Cu, Ni 재질이 충분히 대체가능 할 것으로 판단된다. 다만 원자번호와 밀도의 차이로 인하여 그 두께를 Al의 약 1/10 정도로 조정을 해서 사용하면 적합할 것이다. This study is the material of the additional filter(Cu, Ni, CaWO4, Gd+Ba) being used when the diagnosis X-ray was varied to evaluate the spatial dose distribution accordingly. And it suggest to find a suitable material. Experiments using MCNPX program based on the Monte Carlo simulation method was carried out by selecting the chest and abdomen taken. As a result, each material per dose, the average scatter dose is approximately 62%, 100 ㎝ radius of the point of the simulated body surface exposure dose and 50 ㎝ radius centered on the point average about 47%. It is determined that an Al material is currently available in accordance with the result to be replaced by Cu, Ni material is sufficient. With just the thickness due to the difference in the atomic number and density adjusted to be about one-tenth of the Al it will be suitable.

열가소성 플라스틱 재질과 3D 프린트 필라멘트 재질에대한 방사선량 분석에 관한 연구

이동연(Dong-Yeon Lee) 한국방사선학회 2021 한국방사선학회 논문지 Vol.15 No.2

본 연구는 방사선치료 시 사용하는 고정용구 인 열가소성 플라스틱 마스크를 3D 프린트로 제작하기 위한 선행 연구로써 열가소성 플라스틱을 대체할 수 있는 필라멘트 재질을 분석하고자 진행하였다. 시중에 상용화되어 있는 필라멘트 재질 중 열가소성 플라스틱 마스크와 특성이 유사한 재질을 선택하여 방사선량을 비교 분석하였다. 실험은 몬테칼로 시뮬레이션을 이용하였으며, 마스크가 두부를 고정한 형태를 ICRU 구를 대상으로 모사하고 열가소성 플라스틱 재질과 필라멘트 재질을 적용하여 피부 Hp(0.07), 수정체 Hp(3), 전신 Hp(10) 지점에서 광자 플루언스를 계산하였다. 그 결과 열가소성 플라스틱 재질을 기준으로 상대적인 선량을 보면 차이가 4% 이내로 근사한 값을 나타내었으며, 가장 유사한 선량을 보인 재질은 PA-nylon으로 나타났다. 적절한 필라멘트 재질 선택에 있어서 경제성, 방사선 영향 등 다양한 조건을 종합적으로 고려하여 선택해야 할 것이며, 본 연구 결과를 기초적인 자료로써 활용할 수 있을 것으로 생각된다. This study is a prior research to manufacture a thermoplastic mask, which is a fixture used in radiation therapy, by 3D printing. It proceeded to analyze the filament material that can replace the thermoplastic. Among the commercially available filament materials, a material having similar characteristics to that of a thermoplastic mask was selected and the radiation dose was compared and analyzed. The experiment used Monte Carlo simulation. The shape in which the mask fixed the head was simulated for the ICRU sphere. The photon fluence was calculated at the skin Hp (0.07), the lens Hp (3), and the whole body Hp (10) by applying a thermoplastic plastic material and a filament material. As a result, when looking at the relative dose based on the thermoplastic plastic material, the difference was approximated within 4%. The material showing the most similar dose was PA-nylon. In selecting an appropriate filament material, it should be selected by comprehensively considering various conditions such as economical efficiency and radiation effects. It is thought that the results of this study can be used as basic data.

3D프린팅을 이용한 재활용 디자인에 관한 연구

이동연(Dong Yeon Lee),최명식(myong shik Choi) 경희대학교 산학협력단 예술디자인연구원 2016 예술· 디자인학연구 Vol.19 No.1

In this study, using the 3D printing technology that is sustainable development, now, was trying to become help to solve the environmental problem has become a serious global problem. Technical current 3D printing had developed to such an extent that can make buildings and cooking. And more technically complement the SLS system and Inkjet method that is used in the currently popular, it is very far recycling design plan using the 3D printing if development only technology to change the material required for the 3D printing waste material future will not just talk. If how you look, if enabled 3D printing and recycling design that can be that there is no relationship at all, going to be a lot of help to reduce environmental pollution. This study complements 3D printing skills and makes common to be used easily by people. so I propose the interesting and useful design methods not only just meaning ‘recycling’, also can be interior designing or furniture designing.