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      • SPIM 벡터제어를 위한 태양광 발전 시스템

        고재섭(Jae-Sub Ko),최정식(Jung-Sik Choi),정병진(Byung-Jin Jung),김도연(Do-Yeon Kim),박기태(Ki-Tae Park),최정훈(Jung-Hoon Choi),정동화(Dong-Hwa Chung) 한국조명·전기설비학회 2007 한국조명·전기설비학회 학술대회논문집 Vol.2007 No.11월

        This paper presents the photovoltaic(PV) water pumping system with a maximum power point tracking(MPPT). The water pumping system uses a variable speed single phase induction motor(SPIM) driven a centrifugal pump by field oriented control(FOC) inverter. The MPPT using a DC-DC converter controlled the duty cycle to track maximum power from PV under different insolation conditions. The duty cycle directly relate with a flux producing current control(i<SUB>ds</SUB>). The FOC inverter uses a current control voltage source inverter(CC-VSI). The simulation results are shown that the characteristics and performance of drive system, which varies as each conditions of light by expresses in voltage(V<SUB>dq</SUB>), current(I<SUB>dq</SUB>), speed of motor and torque.

      • IPMSM 드라이브의 최대토크를 위한 적응 FNN 제어기

        김도연(Do-Yeon Kim),고재섭(Jae-Sub Ko),최정식(Jung-Sik Choi),정병진(Byung-Jin Jung),박기태(Ki-Tae Park),최정훈(Jung-Hoon Choi),정동화(Dong-Hwa Chung) 한국조명·전기설비학회 2007 한국조명·전기설비학회 학술대회논문집 Vol.2007 No.11월

        Interior permanent magnet synchronous motor(IPMSM) has become a popular choice in electric vehicle applications, due to their excellent power to weight ratio. This paper proposes maximum torque control of IPMSM drive using adaptive fuzzy neural network controller and artificial neural network(ANN). This control method is applicable over the entire speed range which considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current i<SUB>d</SUB> for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using Adaptive-FNN controller and ANN controller. The hybrid combination of neural network and fuzzy control will produce a powerful representation flexibility and numerical processing capability. Also, this paper proposes speed control of IPMSM using Adaptive-FNN and estimation of speed using ANN controller. The back propagation neural network technique is used to provide a real time adaptive estimation of the motor speed. The proposed control algorithm is applied to IPMSM drive system controlled Adaptive-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper proposes the analysis results to verify the effectiveness of the Adaptive-FNN and ANN controller.

      • 태양광 발전을 이용한 유도전동기 드라이브의 벡터제어

        정병진(Byung-Jin Jung),고재섭(Jae-Sub Ko),최정식(Jung-Sik Choi),김도연(Do-Yeon Kim),정동화(Dong-Hwa Jung) 한국조명·전기설비학회 2008 한국조명·전기설비학회 학술대회논문집 Vol.2008 No.10월

        This paper is proposed the vector control of 3-phase induction motor drive system by photovoltaic generation. For performance of vector control using a current control voltage source inverter(CC-VSI). CC-VSI is controlled by torque and flux producing component of motor current, relating with current and and voltage value of photovoltaic arrays at maximum power point that varies follow different level of insolation. The MPPT using a DC-DC converter controlled the duty cycle to track maximum power from PV under different insolation conditions. The simulation results are shown that the characteristics and performance of drive system, which varies as each conditions of light by expresses in voltage(V<SUB>dq</SUB>), current(I<SUB>dq</SUB>), speed of motor and torque.

      • Cadmium과 Di-(2-ethylhexyl) Phthalate에 의한 고환 독성 : 아연과 Apoptosis의 역할 The Role of Zinc and Apoptosis

        권민,최병선,박언섭,홍연표,박정덕 중앙대학교 의과대학 의과학연구소 2003 中央醫大誌 Vol.28 No.1

        Cadmium (Cd) and di-(2-ethylhexyl) phthalate are used widely and distributed ubiquitously in the environment, which are well-known reproductive toxicants. DEHP and/or Cd causes the apoptosis, degeneration of spermatogenic cells, and massive necrosis, resulting in testicular atrophy. Zinc is an essential metal in spermatogenesis, the zinc concentration in testis is changed in DEHP- or Cd-treated animals. However, the role of zinc or apoptosis in testicular toxicity by DEHP or Cd has not been understood well. In this study, Sprague-Dawley male rats were given DEHP (2 g/kg, 5 ml corn-oil, PO) or Cd (CdCl₂2 mg/kg, 4 ml saline, sc) for 1, 2, 7 and 14 days. Control rats were given vehicle corresponding to each group. At day 1, 2, 7, and 14 after administration of DEHP or Cd, the morphological findings including apoptosis in testes were observed under the light microscope, and the zinc concentrations in testes were determined by atomic absorption spectrometry with flame method. Fas and FasL mRNA in testes were analyzed by RT-PCR method at 12 hours, 1, 7, 14 days after adminstration of DEHP or Cd. Absolute and relative testicular weight were lower in DEHP- or Cd-treated rats than control. DEHP or Cd produced morphological changes in testes, including apoptosis, degeneration, necrosis and massive loss of spermatogenic cells, resulting in testicular atrophy. The zinc concentration in testes was not different at day 1 after administration of DEHP, but was decreased at later times. Testicular zinc was lower at day 1, 2 in Cd-treated rats than control, but was higher at 7, 14 days after Cd administration. The levels of Fas and FasL mRNA were highly expressed in testes after administration of DEHP or Cd. These results suggest that the change of zinc level in testes might be a secondary effect of DEHP- or Cd-induced testicular toxicity, and Fas signal system might be play an important role in pocessing of apoptosis in testes by DEHP or Cd.

      • KCI등재

        Prediction of Decompensation and Death in Advanced Chronic Liver Disease Using Deep Learning Analysis of Gadoxetic Acid-Enhanced MRI

        Heo Subin,이승수,Kim So Yeon,Lim Young-Suk,Park Hyo Jung,Yoon Jee Seok,Suk Heung-Il,Sung Yu Sub,Park Bumwoo,Lee Ji Sung 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.12

        Objective: This study aimed to evaluate the usefulness of quantitative indices obtained from deep learning analysis of gadoxetic acid-enhanced hepatobiliary phase (HBP) MRI and their longitudinal changes in predicting decompensation and death in patients with advanced chronic liver disease (ACLD). Materials and Methods: We included patients who underwent baseline and 1-year follow-up MRI from a prospective cohort that underwent gadoxetic acid-enhanced MRI for hepatocellular carcinoma surveillance between November 2011 and August 2012 at a tertiary medical center. Baseline liver condition was categorized as non-ACLD, compensated ACLD, and decompensated ACLD. The liver-to-spleen signal intensity ratio (LS-SIR) and liver-to-spleen volume ratio (LS-VR) were automatically measured on the HBP images using a deep learning algorithm, and their percentage changes at the 1-year follow-up (ΔLS-SIR and ΔLS-VR) were calculated. The associations of the MRI indices with hepatic decompensation and a composite endpoint of liver-related death or transplantation were evaluated using a competing risk analysis with multivariable Fine and Gray regression models, including baseline parameters alone and both baseline and follow-up parameters. Results: Our study included 280 patients (153 male; mean age ± standard deviation, 57 ± 7.95 years) with non-ACLD, compensated ACLD, and decompensated ACLD in 32, 186, and 62 patients, respectively. Patients were followed for 11–117 months (median, 104 months). In patients with compensated ACLD, baseline LS-SIR (sub-distribution hazard ratio [sHR], 0.81; p = 0.034) and LS-VR (sHR, 0.71; p = 0.01) were independently associated with hepatic decompensation. The ∆LS-VR (sHR, 0.54; p = 0.002) was predictive of hepatic decompensation after adjusting for baseline variables. ∆LS-VR was an independent predictor of liver-related death or transplantation in patients with compensated ACLD (sHR, 0.46; p = 0.026) and decompensated ACLD (sHR, 0.61; p = 0.023). Conclusion: MRI indices automatically derived from the deep learning analysis of gadoxetic acid-enhanced HBP MRI can be used as prognostic markers in patients with ACLD.

      • SCIESCOPUSKCI등재

        Haplogroup Classification of Korean Cattle Breeds Based on Sequence Variations of mtDNA Control Region

        Kim, Jae-Hwan,Lee, Seong-Su,Kim, Seung Chang,Choi, Seong-Bok,Kim, Su-Hyun,Lee, Chang Woo,Jung, Kyoung-Sub,Kim, Eun Sung,Choi, Young-Sun,Kim, Sung-Bok,Kim, Woo Hyun,Cho, Chang-Yeon Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.5

        Many studies have reported the frequency and distribution of haplogroups among various cattle breeds for verification of their origins and genetic diversity. In this study, 318 complete sequences of the mtDNA control region from four Korean cattle breeds were used for haplogroup classification. 71 polymorphic sites and 66 haplotypes were found in these sequences. Consistent with the genetic patterns in previous reports, four haplogroups (T1, T2, T3, and T4) were identified in Korean cattle breeds. In addition, T1a, T3a, and T3b sub-haplogroups were classified. In the phylogenetic tree, each haplogroup formed an independent cluster. The frequencies of T3, T4, T1 (containing T1a), and T2 were 66%, 16%, 10%, and 8%, respectively. Especially, the T1 haplogroup contained only one haplotype and a sample. All four haplogroups were found in Chikso, Jeju black and Hanwoo. However, only the T3 and T4 haplogroups appeared in Heugu, and most Chikso populations showed a partial of four haplogroups. These results will be useful for stable conservation and efficient management of Korean cattle breeds.

      • SCISCIESCOPUS

        Rate capability for Na-doped Li<sub>1.167</sub>Ni<sub>0.18</sub>Mn<sub>0.548</sub>Co<sub>0.105</sub>O<sub>2</sub> cathode material and characterization of Li-ion diffusion using galvanostatic intermittent titration technique

        Lim, Sung Nam,Seo, Jung Yoon,Jung, Dae Soo,Ahn, Wook,Song, Hoon Sub,Yeon, Sun-Hwa,Park, Seung Bin Elsevier 2015 JOURNAL OF ALLOYS AND COMPOUNDS Vol.623 No.-

        <P><B>Abstract</B></P> <P>Spherical Li<SUB>1.167</SUB> <SUB>−</SUB> <I> <SUB>x</SUB> </I>Na<I> <SUB>x</SUB> </I>Ni<SUB>0.18</SUB>Mn<SUB>0.548</SUB>Co<SUB>0.105</SUB>O<SUB>2</SUB> (0⩽ <I>x</I> ⩽0.1) particles were prepared by spray pyrolysis, and subjected to electrochemical characterization for lithium battery applications. It was confirmed that Na doping enhances the charge/discharge rate capability. The structure of prepared samples was characterized by XRD: the <I>c</I>-axis lattice parameter increases with increase in the amount of Na ions (parameterized by <I>x</I>, above). The Na-doped sample with <I>x</I> =0.05 shows capacities of 208 and 184mAhg<SUP>−1</SUP> at high current densities of 1.0C and 2.0C, respectively. These values are enhanced, compared to values of 189 and 167mAhg<SUP>−1</SUP> for the bare sample. The ratio of the capacity at 1.0C to that at 0.1C is enhanced from 77% for the bare sample to 84% for the Na-doped sample with <I>x</I> =0.05. The Li diffusion coefficients obtained from the galvanostatic intermittent titration technique (GITT) are higher for Na-doped samples than for the bare sample. In particular, the Na-doped sample (<I>x</I> =0.05), in the potential range around 4V, has a higher <I>D</I> <SUB>Li+</SUB> value of 3.34×10<SUP>−9</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP>, compared with 1.35×10<SUP>−9</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP> for the bare sample. The Na-doped samples (0< <I>x</I> <0.075) show high capacity retention: the Na-doped sample (<I>x</I> =0.05) shows a capacity retention of 92% compared to 83% for the bare sample.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spherical Na-doped Li-rich cathode material prepared by spray pyrolysis. </LI> <LI> Na-doped samples show better rate capability than that of bare sample. </LI> <LI> Na-doped sample has higher <I>D</I> <SUB>Li+</SUB> value at 4V compared with that of the bare sample. </LI> <LI> The cycle performance was enhanced from 83% to 92%. </LI> </UL> </P>

      • Reliable oxygen transfer in MgAl<sub>2</sub>O<sub>4</sub> spinel through the reversible formation of oxygen vacancies by Cu<sup>2+</sup>/Fe<sup>3+</sup> anchoring

        Do, Jeong Yeon,Son, Namgyu,Park, No-Kuk,Kwak, Byeong Sub,Baek, Jeom-In,Ryu, Ho-Jung,Kang, Misook Elsevier 2018 APPLIED ENERGY Vol.219 No.-

        <P><B>Abstract</B></P> <P>This study focused on Cu<SUB>x</SUB>Mg<SUB>1-x</SUB>Fe<SUB>y</SUB>Al<SUB>2-y</SUB>O<SUB>4</SUB> oxygen carriers for application in the chemical looping combustion of methane. Cu<SUB>x</SUB>Mg<SUB>1-x</SUB>Fe<SUB>y</SUB>Al<SUB>2-y</SUB>O<SUB>4</SUB> was fabricated by simultaneously substituting Mg<SUP>2+</SUP> and Al<SUP>3+</SUP> with Cu<SUP>2+</SUP> and Fe<SUP>3+</SUP> in the spinel structure of MgAl<SUB>2</SUB>O<SUB>4</SUB>. As a result, a great synergistic effect was observed: Cu<SUB>0.75</SUB>Mg<SUB>0.25</SUB>Fe<SUB>1.5</SUB>Al<SUB>0.5</SUB>O<SUB>4</SUB> exhibited 7.85% oxygen transfer capacity in the CH<SUB>4</SUB>-CO<SUB>2</SUB>/air redox system. Methane and carbon monoxide were significantly adsorbed on the surface of the Cu<SUB>x</SUB>Mg<SUB>1-x</SUB>Fe<SUB>y</SUB>Al<SUB>2-y</SUB>O<SUB>4</SUB> particles. Cyclic voltammetry studies predicted the active lifetime of the oxygen carrier, which had not been reported until now. Cu<SUB>0.75</SUB>Mg<SUB>0.25</SUB>Fe<SUB>1.5</SUB>Al<SUB>0.5</SUB>O<SUB>4</SUB> was expected to exhibit the greatest oxygen transfer capacity after 300 redox cycles and maintain an oxygen transfer efficiency of 92% until the 1000th redox cycle in the H<SUB>2</SUB>-N<SUB>2</SUB>/air redox system. This study concluded that the active metal species, containing Cu<SUP>2+</SUP> and Fe<SUP>3+</SUP> ions, were stably anchored in the spinel structure; this led to the reversible formation of oxygen vacancies in the spinel structure, resulting in an excellent oxygen transfer capacity that could be maintained for a long time.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu<SUB>x</SUB>Mg<SUB>1-x</SUB>Fe<SUB>y</SUB>Al<SUB>2-y</SUB>O<SUB>4</SUB> spinel structured oxygen carriers were successfully prepared. </LI> <LI> Reversible oxygen vacancies were observed in a Cu<SUB>x</SUB>Mg<SUB>1-x</SUB>Fe<SUB>y</SUB>Al<SUB>2-y</SUB>O<SUB>4</SUB> spinel structure. </LI> <LI> CH<SUB>4</SUB> and CO gases were much adsorbed on the surface of Cu<SUB>0.75</SUB>Mg<SUB>0.25</SUB>Fe<SUB>1.5</SUB>Al<SUB>0.5</SUB>O<SUB>4</SUB> spinel particle. </LI> <LI> The greatest oxygen transfer in Cu<SUB>0.75</SUB>Mg<SUB>0.25</SUB>Fe<SUB>1.5</SUB>Al<SUB>0.5</SUB>O<SUB>4</SUB> particle was obtained. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Reliable oxygen transfer in MgAl<SUB>2</SUB>O<SUB>4</SUB> spinel through the reversible formation of oxygen vacancies by Cu<SUP>2+</SUP>/Fe<SUP>3+</SUP> anchoring.</P> <P>[DISPLAY OMISSION]</P>

      • PV 시스템을 이용한 단상유도전동기의 벡터제어

        고재섭(Jae-Sub Ko),최정식(Jung-Sik Choi),정병진(Byung-Jin Jung),김도연(Do-Yeon Kim),박기태(Ki-Tae Park),최정훈(Jung-Hoon Choi),정동화(Dong-Hwa Chung) 대한전기학회 2007 대한전기학회 학술대회 논문집 Vol.2007 No.10

        The water pumping system uses a variable speed single phase induction motor driven a centrifugal pump by field oriented control(FOC) inverter. The MPPT using a DC-DC converter controlled the duty cycle to track maximum power from PV under different insolation conditions. The duty cycle directly relate with a flux producing current control(i<SUB>ds</SUB>). The FOC inverter uses a current control voltage source inverter(CC-VSI). The simulation results are shown that the characteristics and performance of drive system, which varies as each conditions of light by expresses in voltage(V<SUB>dq</SUB>), current(I<SUB>dq</SUB>), speed of motor and torque.

      • The Application of Magnetic Resonance Imaging-Deformed <sup>11</sup>C-Methionine-Positron Emission Tomography Images in Stereotactic Radiosurgery

        Jung, Tae-Young,Jung, Shin,Ryu, Han-Seung,Kim, In-Young,Jang, Woo-Youl,Moon, Kyung-Sub,Lim, Sa-Hoe,Kim, Dong-Yeon,Kang, Sae-Ryung,Min, Jung-Joon,Bom, Hee-Seung,Kim, Seul-Kee,Kwon, Seong Young S. Karger AG 2019 Stereotactic and functional neurosurgery Vol.97 No.4

        <P><B><I>Background:</I></B> Although <sup>11</sup>C-methionine positron emission tomography (MET-PET) images can be fused with magnetic resonance (MR) images using planning software for gamma knife radiosurgery (GKR), the stereotactic information has limited value in patients with recurrent malignant brain tumor due to the difference in imaging protocols between MET-PET and MR images. The aim of this study was to evaluate the clinical application of MR imaging (MRI)-deformed MET-PET images in GKR using a deformable registration tool. <B><I>Methods:</I></B> We examined the enhanced MR stereotactic images, MET-PET and MRI-deformed MET-PET images without stereotactic information for 12 newly developed metastatic brain tumors. MET-PET and MRI-deformed MET-PET images were co-registered with the MR stereotactic images using radiosurgery planning software. Visual analysis was performed to determine whether the MET-PET and MR images matched better after using the deformable registration tool. In addition, the matching volume between MR and MET-PET images was compared before and after applying this tool. The matching volume was calculated as the metabolic tumor volume on the MET-PET images, including the MR-enhanced volume. The matching percentage was calculated as the matching volume divided by the MR-enhanced volume, multiplied by 100. <B><I>Results:</I></B> Visual analysis revealed that the MRI-deformed MET-PET images provided the same axial plane as that of the MR images, with the same window level, enabling easy identification of the tumor with the radiosurgery planning software. The mean matching percentage of the MET-PET/MR fusion images was 61.1% (range 24.7-94.7) and that of the MRI-deformed MET-PET/MR fusion images was 63.4% (range 20.8-94.3). No significant difference was found in the matching percentage between the two types of fusion images (<I>p</I> = 0.754). <B><I>Conclusions:</I></B> The MRI-deformed MET-PET images enable utilization of the functional information when planning a treatment in GKR without significant volume change.</P>

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