• 한국미생물·생명공학회지
• /
• 제47권4호
• /
• pp.667-672
• /
• 2019

본 연구는 출아효모 Saccharomyces cerevisiae을 이용해 이종 유전자(heterologous gene)를 효모염색체내에 도입하여 안정적으로 발현하기 위한 시스템의 비교에 대해서 연구하였다. 반복적으로 사용할 수 있는 Cre/loxP system의 이용을 위해 C. glabrata 유래 유전자를 선택마커로 사용하였고, universal pRS-CMT vector를 이용한 4종의 유전자(XYLP, XYLB, GRE3 및 XYL2 유전자)를 모델 유전자로 cloning하였다. 구축된 pRS-XylP, pRS-XylB, pRS-Gre3 및 pRS-Xyl2 plasmid를 이용한 4번의 sequential integration을 통해 효모염색체내에 도입된 4종의 유전자를 순차적으로 발현시킬 수 있었다. 또한 4종의 유전자 발현 cassette를 동시에 가지는 pRS-PBG2 plasmid에 의한 one-step integration을 통해서, 도입될 유전자들의 순서를 정할 수 있었으며 각 유전자들의 동시발현을 안정적으로 유지할 수 있었다. 결론적으로 본 연구에서 사용한 4종의 유전자들의 염색체내 동시 integration 및 발현을 위해서는 one-step integration이 효과적임을 확인하였으며, 적절한 유전자 도입방법을 통해 산업적으로 유용한 생물시스템의 손쉬운 육종이 가능하리라 기대한다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2008년도 추계학술대회 논문집
• /
• pp.127-128
• /
• 2008

• 중소기업융합학회논문지
• /
• 제4권1호
• /
• pp.17-29
• /
• 2014

무선 캡슐 내시경은 소장 질환을 진단하는 등의 어려움을 해결하는 진화 의료 기기로서 중요한 역할을 했다. 그것은 제한된 크기와 기능 때문에 몇 가지 단점이 있다. 가장 큰 장애물은 자기 운동 장애에서 속도 문제를 제공할 수 없다는 점이다. 따라서, 인간의 소화 시스템의 특성을 간단히 내시경 역학의 정보를 얻기 위해, 특히 소장을 소개한다. 조건 추출을 확인하기 위해서 LuGre 모델이라는 새로운 동적 마찰 모델을 도입하고 명확하게 특성 및 모델의 사용을 얻기 위하여 분석한다. 캡슐 내시경의 실제 상황과 관련된 매개 변수의 고려하여 매트랩 시뮬링크는 모델을 작성하는 데 적용하고 기능을 발견 할 수있는 시뮬레이션을 통해 확인하였다.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
• /
• pp.109-109
• /
• 2001

Purpose： To assess the feasibility of sequential administration of ferumoxides and mangafodi trisodium in the same imaging protocols. Method： Thirty patients underwent double-contrast enhanced MR imaging of liver usi ferumoxides (Fe-MRI) and mangafodipir trisodium (Mn-MRI) on 1.5T GE Horizon system. In twenty patients, Mn-MRI was immediately followed by Fe-MRI. In ten patients, Fe-MR was performed first, then Mn-MRI was performed immediately, In all cases, precontras T1-weighted in-phase and opposed-phase spoiled gradient echo (GRE) images an T2-weighted fast spin-echo images (TR 4000ms, TE 102ms, ETL 8-12) were obtained Fe-MRI was performed with FSE and steady state GRE (TE 10 msec, flip angle 30 sequences. Mn-MRI was performed with in-phase and opposed-phase spoiled GR sequences. The SNR changes after the use of each contrast agents were calculated.

• Investigative Magnetic Resonance Imaging
• /
• 제23권4호
• /
• pp.390-394
• /
• 2019

Hemosiderosis is characterized by the deposition of excess iron in body tissues. The choroid plexus is an important part of the central nervous system that can be the primary site of iron overload. T2*-weighted gradient echo (GRE) sequence provides high sensitivity for demonstrating cerebral microhemorrhagic foci and iron deposition. In the present study, we describe the case of a 15-year-old boy with acute lymphoblastic leukemia, in whom repeated transfusion led to iron accumulation in the brain. GRE sequence effectively demonstrated hemosiderin deposition in the choroid plexus.

• 한국공작기계학회논문집
• /
• 제18권1호
• /
• pp.50-58
• /
• 2009

For precise tracking control of a servo system with nonlinear friction, a robust friction compensation scheme is presented in this paper. The nonlinear friction is difficult to identify the friction parameters exactly through experiments. Friction parameters can be also varied according to contact conditions such as the variation of temperature and lubrication. Thus, in order to overcome these problems and obtain the desired position tracking performance, a robust adaptive back-stepping control scheme with a dual friction observer is developed. In addition, to estimate lumped friction uncertainty due to modeling errors, a DEKF recurrent neural network and adaptive reconstructed error estimator are also developed. The feasibility of the proposed control scheme is verified through the experiment fur a ball-screw system.

• Investigative Magnetic Resonance Imaging
• /
• 제23권4호
• /
• pp.328-340
• /
• 2019

Purpose: To generate phase images with free of motion-induced artifact and susceptibility-induced distortion using 3D radial ultrashort TE (UTE) MRI. Materials and Methods: The field map was theoretically derived by solving Laplace's equation with appropriate boundary conditions, and used to simulate the image distortion in conventional spin-warp MRI. Manufacturer's 3D radial imaging sequence was modified to acquire maximum number of radial spokes in a given time, by removing the spoiler gradient and sampling during both rampup and rampdown gradient. Spoke direction randomly jumps so that a readout gradient acts as a spoiling gradient for the previous spoke. The custom raw data was reconstructed using a homemade image reconstruction software, which is programmed using Python language. The method was applied to a phantom and in-vivo human brain and abdomen. The performance of UTE was compared with 3D GRE for phase mapping. Local phase mapping was compared with T₂* mapping using UTE. Results: The phase map using UTE mimics true field-map, which was theoretically calculated, while that using 3D GRE revealed both motion-induced artifact and geometric distortion. Motion-free imaging is particularly crucial for application of phase mapping for abdomen MRI, which typically requires multiple breathold acquisitions. The air pockets, which are caught within the digestive pathway, induce spatially varying and large background field. T₂* map, that was calculated using UTE data, suffers from non-uniform T₂* value due to this background field, while does not appear in the local phase map of UTE data. Conclusion: Phase map generated using UTE mimicked the true field map even when non-zero susceptibility objects were present. Phase map generated by 3D GRE did not accurately mimic the true field map when non-zero susceptibility objects were present due to the significant field distortion as theoretically calculated. Nonetheless, UTE allows for phase maps to be free of susceptibility-induced distortion without the use of any post-processing protocols.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
• /
• pp.219-224
• /
• 1992

This paper deals with the linear quadratic optimal regulator problem for descriptor systems without performing a preliminary transformation for a descriptor system. We derive a generalized Riccati differential equation (GRDE) based on the two-point boundary value problem for a Hamiltonian equation. We then obtain an optimal feedback control and the optimal cost in terms of the solution of GRE. A simple example is included.

• 대한전기학회논문지
• /
• 제43권4호
• /
• pp.648-657
• /
• 1994

This paper presents a solution of the H$\infty$ control problem for a linear singularly perturbed system. A sufficient condition for a linear singularly perturbed system to achieve the prescribed disturbance attenuation level is obtained. Based upon this sufficient condition, an H$\infty$ controller design method which involves the solutions of two generalized algebraic Riccati equations(GRE) is developed.

• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2014년도 제49차 동계학술대회논문집 22권1호
• /
• pp.467-468
• /
• 2014

본 논문에서는 파일 내용 기반 검색 프로그램을 설계하고 구현하였다. 역 인덱스 구조를 이용하여 설계하였으며 별도의 정보 검색 라이브러리 사용 없이 구현하였다. 인덱스 파일은 트라이 자료 구조를 직접 설계 및 구현 하였으며 자바 언어의 HashMap 구조를 중첩 형태로 구현하였다. 개발 시스템의 유용성을 테스트하기 위해 GRE 단어집에 수록된 약 3,300개의 단어를 사용하여 임의 생성한 텍스트 파일 집합을 사용하였다.