http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Lee, Hyeok-Won,Park, Jung-Ho,Lee, Hee-Suk,Kim, Chun-Suk,Lee, Jin-Gyeom,Kim, Won-kyo,Ryu, Kyoung-Hwa,Ahn, Jung-Oh,Lee, Eun-Gyo,Kim, Seon-Won,Jeon, Jong-Min,Yang, Yung-Hun,Choi, Eui-Sung,Lee, Hong-Weon Society for Bioscience and Bioengineering, Japan 2019 Journal of bioscience and bioengineering Vol. No.
<P>Many volatile compounds, such as isoprene, a precursor used in the synthesis of natural rubber, have been produced through fermentation using genetically engineered microorganisms. Despite this biotechnological success, measuring the concentrations of volatile compounds during fermentation is difficult because of their high volatility. In current systems, off-line analytical methods usually lead to product loss, whereas on-line methods raise the production cost due to the requirement of complex devices. Here, we developed a novel on-line gas chromatography (GC)-based system for analyzing the concentration of isoprene with the aim to minimize the cost and requirement for devices as compared to current strategies. In this system, a programmable logic controller is used to combine conventional GC with a syringe pump module (SPM) directly connected to the exhaust pipe of the fermentor, and isoprene-containing samples are continuously pumped from the SPM into the GC using an air cylinder recycle stream. We showed that this novel system enables isoprene analysis during fermentation with convenient equipment and without the requirement of an expensive desorption tube. Furthermore, this system may be extended to the detection of other volatile organic compounds in fermentation or chemical processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This system analyzes the concentration of isoprene in aerobic fermentation. </LI> <LI> PLC is used to combine conventional GC with SPM directly connected to fermenter. </LI> <LI> Produced isoprene is continuously analyzed using the GC. </LI> <LI> This system may be extended to the detection of other volatile organic compounds. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Lee, Jae-Won,Kim, Won-Ki,Oh, Yun-Sik,Seo, Hun-Chul,Jang, Won-Hyeok,Kim, Yoon Sang,Park, Chul-Won,Kim, Chul-Hwan The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3
An algorithm for fault detection and classification method for wide-area protection in Korean transmission systems is proposed. The modeling of 345-kV and 765-kV Korean power system transmission networks using the Electro Magnetic Transient Program - Restructured Version (EMTP-RV) is presented and the algorithm for fault detection and classification in transmission lines is developed. The proposed algorithm uses the Wavelet Transform (WT) and Singular Value Decomposition (SVD). The Singular value of Approximation coefficient (SA) and part Sum of Detail coefficient (SD) are introduced. The characteristics of the SA and SD at the fault conditions are analyzed and used in the algorithm for fault detection and classification. The validation of the proposed algorithm is verified by various simulation results.
A Study on Fatigue Damage Modeling Using Neural Networks
Lee Dong-Woo,Hong Soon-Hyeok,Cho Seok-Swoo,Joo Won-Sik The Korean Society of Mechanical Engineers 2005 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.19 No.7
Fatigue crack growth and life have been estimated based on established empirical equations. In this paper, an alternative method using artificial neural network (ANN) -based model developed to predict fatigue damages simultaneously. To learn and generalize the ANN, fatigue crack growth rate and life data were built up using in-plane bending fatigue test results. Single fracture mechanical parameter or nondestructive parameter can't predict fatigue damage accurately but multiple fracture mechanical parameters or nondestructive parameters can. Existing fatigue damage modeling used this merit but limited real-time damage monitoring. Therefore, this study shows fatigue damage model using backpropagation neural networks on the basis of X -ray half breadth ratio B / $B_o$, fractal dimension $D_f$ and fracture mechanical parameters can estimate fatigue crack growth rate da/ dN and cycle ratio N / $N_f$ at the same time within engineering limit error ($5\%$).
Lee, Dong-Hyeok,Seh, Soo-Won,An, Hyuk,Min, Byoung-Goo The Korean Society of Medical and Biological Engin 1994 의공학회지 Vol.15 No.4
The most serious problems related to the cardiovascular prothesis are thrombosis and hemolysis. It is known that the flow pattern of cardiovascular prostheses is highly correlated with thrombosis and hemolysis. Laser Doppler Anemometry (LDA) is a usual method to get flow pattern, which is difficult to operate and has narrow measure region. Particle Image Velocimetry (PIV) can solve these problems. Because the flow speed of valve is too high to catch particles by CCD camera, high-speed camera (Hyspeed : Holland-Photonics) was used. The estimated maximum flow speed was 5m/sec and maximum trackable length is 0.5 cm, so the shutter speed was determined as 1000 frames per sec. Several image processing techniques (blurring, segmentation, morphology, etc) were used for the preprocessing. Particle tracking algorithm and 2-D interpolation technique which were necessary in making gridrized velocity pronto, were applied to this PIV program. By using Single-Pulse Multi-Frame particle tracking algorithm, some problems of PIV can be solved. To eliminate particles which penetrate the sheeted plane and to determine the direction of particle paths are these solving methods. 1-D relaxation fomula is modified to interpolate 2-D field. Parachute artificial heart valve which was developed by Seoul National University and Bjork-Shiely valve was testified. For each valve, different flow pattern, velocity profile, wall shear stress and mean velocity were obtained.
Globus Pallidus Interna Deep Brain Stimulation for Chorea-Acanthocytosis
Lee, Jae-Hyeok,Cho, Won-Ho,Cha, Seung-Heon,Kang, Dong-Wan The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.57 No.2
Chorea-acanthocytosis (ChAc) is a rare hereditary disorder characterized by involuntary choreiform movements and erythrocytic acanthocytosis. Pharmacotherapy for control of involuntary movements has generally been of limited benefit. Deep brain stimulation (DBS) has recently been used for treatment of some refractory cases of ChAc. We report here on the effect of bilateral high-frequency DBS of globus pallidus interna in a patient with ChAc.
Lee, Ji Young,Kim, Hyo Jeong,Yoon, Nal Ae,Lee, Won Hyeok,Min, Young Joo,Ko, Byung Kyun,Lee, Byung Ju,Lee, Aran,Cha, Hee Jeong,Cho, Wha Ja,Park, Jeong Woo Oxford University Press 2013 Nucleic acids research Vol.41 No.11
<P>Tristetraprolin (TTP) and <I>let-7</I> microRNA exhibit suppressive effects on cell growth through down-regulation of oncogenes. Both TTP and <I>let-7</I> are often repressed in human cancers, thereby promoting oncogenesis by derepressing their target genes. However, the precise mechanism of this repression is unknown. We here demonstrate that p53 stimulated by the DNA-damaging agent doxorubicin (DOX) induced the expression of <I>TTP</I> in cancer cells. TTP in turn increased <I>let-7</I> levels through down-regulation of <I>Lin28a</I>. Correspondingly, cancer cells with mutations or inhibition of p53 failed to induce the expression of both <I>TTP</I> and <I>let-7</I> on treatment with DOX. Down-regulation of <I>TTP</I> by small interfering RNAs attenuated the inhibitory effect of DOX on <I>let-7</I> expression and cell growth. Therefore, TTP provides an important link between p53 activation induced by DNA damage and <I>let-7</I> biogenesis. These novel findings provide a mechanism for the widespread decrease in TTP and <I>let-7</I> and chemoresistance observed in human cancers.</P>