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상태관측기를 이용한 영구자석 동기전동기의 센서리스 속도제어
손문경,이동희,오석규 진주산업대학교 1999 산업과학기술연구소보 Vol.- No.6
Sensorless PMSM is much studied for the industrial applications and home appliances because a mechanical sensor reduces reliability and increases cost. This paper investigates a field oriented control method without speed and rotor position sensor using the state observer. The observer is based on the model of the motor represented in the stationary two-axes coordinates. The control strategy is to estimate back-EMF by the state observer and to estimate the rotor speed and the rotor position angle from the estimated back-EMF. And we construct back-EMF constant compensator to compensate estimated speed error due to detuned electrical parameter. The observer is tested by simulation and experiment. The results show that the observer gives a good estimation of speed and rotor position, compensated parameter constants. The simulation and experimental results indicate good performances.
진화전략과 상태 관측기에 의한 영구자석 동기전동기의 센서리스 속도제어기 설계에 관한 연구
손문경,이동희,오석규 진주산업대학교 1999 산업과학기술연구소보 Vol.- No.6
Permanent magnet synchronous motor is widely applied for the industrial and home appliance because of it`s high power density and easy control. Recently sensorless speed control of PMSM is much studied because a mechanical sensor reduces reliability and increases cost. This paper investigates sensorless controller design of PMSM. Angular speed and position are estimated with observer. In order to reduce variation effect of mechanical parameters and calculation delay, reduced order state observer is designed with electrical parameters. Evolution strategy is used to optimize controller gains and observer eigenvalue. In the sensorless control of PMSM with state observer, eigenvalue affect stability and dynamic response of system,. The simulation and experimental results indicate good performances.
Carry Lookahead Adder의 면적 감소 방안에 관한 연구
고행석,장경선 충남대학교 산업기술연구소 2003 산업기술연구논문집 Vol.18 No.1
Though, Carry Lookahead Adder is widely used since it is fast, it takes large area. This paper presents a method to enhance the area-time product by replacing a part of lookahead carry propagations with ripple carry propagations. The proposed scheme reduces the area by 20% while it increases one or two levels of gate delays regardless of the number of bits. With experiments, we noticed that the proposed method is effective especially when it is implemented on a fine-grained FPGA with mux-based structure.
열공형과 비열공형 피질하 혈관성 치매에서 위험인자의 차이에 관한 비교 연구
배희준,정지향,유경호,나덕렬,김상윤,최경규,양동원,손의주,이상도,김재우,박경원,김응규,이재홍,박미영,한일우,함동석,최문성,하충건,최성혜,이애영,이병철,한설희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.2
Backgrounds and Objectives: Vascular dementia is a group of dementing disoders arising from various stroke syndrome. Among these. subcortical ischemic vascular dementia (SIVD) is regarded as a relatively distinct clinical entity. However, MRI patterns of SIVD are not homogenous. In some patients, lacunes are dominant, and in others, subcortical white matter changes are. This study was designed to compare risk factor profiles between SIVD with and without multiple lacunes. Methods: We divided 47 subjects (22 males, mean age. 68 years) recruited from VADAPET (Multicenter Trial For Evaluation Of The Changes In the PET Images Of Subcortical Vascular Dementia Patient) study into two groups one with more than 5 lacunes in deep gray matter (lacune group) and the other with 5 or less(non-lacune group) Clinical characteristics and laboratory findings of two groups were compared. Results: Nineteen of 47 patients (40%) belonged to the lacune group. The lacune and non-lacune groups d d not differ in the following variables: age, hypertension, diabetes mellitus, hyperlipidemia heart disease, history of stroke or TIA, history of trauma or major surgery, family history of hypertension stroke, or dementia, age at diagnosis of dementia, body mass index, white blood cell count, ESR, CRP, fibrinogen, hemoglobin A1C, total cholesterol. LDL cholesterol creatinine, proteinuria, glucosuria, and microhematuria. However, male sex, smoking alcohol. hemoglobin, and HDL cholesterol were possibly associated more with lacune group SIVD than with non-lacune group (p<0 1) Multivariate analyses revealed that smoking, hemoglobin, and HDL cholesterol were independent predictors of SIVD with multiple lacunes Conclusion: Our study suggests that SIVD with multiple lacunes may be significantly different in smoking habits hemoglobin, and HDL cholesterol from SIVD without multiple lacunes.
Kyoung Seok Son,Dae Lim Choi,이호년,Won Geon Lee 한국물리학회 2002 Current Applied Physics Vol.2 No.3
In fringe field switching (FFS) device, the distance (l) between electrodes should be smaller than the cell gap (d) to generate fringe field. In order to increase the transmittance, common and pixel electrodes which are separated with the insulator should be transparent conductive materials. When the silicon-nitride by plasma enhanced chemical vapor deposition using SiH4 gas is deposited on ITO in FFS device, the radical containing hydrogen causes the reduction of the indium-oxide to metallic indium on the film surface and finally the decrease of transmittance in visible range. To prohibit the reduction of In, the reduction of SiH4 flow rate is needed. Therefore we suggest the two-step process in depositing the SiNx consisting of a buffer-SiNx layer and a bulk-SiNx layer. 2002 Published by Elsevier Science B.V.
Son, Sung-Ho,Yang, Seo-Jin,Jeon, Hye-Lin,Yu, Hyung-Seok,Lee, Na-Kyoung,Park, Young-Seo,Paik, Hyun-Dong Elsevier 2018 Microbial pathogenesis Vol.125 No.-
<P><B>Abstract</B></P> <P>This study aimed to isolate and demonstrate their antioxidant and immunostimulatory activities of potential probiotics. The isolated strains, S. Pum19, SC28, and SC61 showed potential probiotic properties including stability in artificial gastric and bile conditions, non-production of β-glucuronidase, suitable antibiotic susceptibility, and attachment to intestinal cells. S. Pum19, SC28, and SC61 strains were identified as <I>Leuconostoc citreum</I>, <I>Pediococcus pentosaceus</I>, and <I>Lactobacillus paraplantarum</I>, respectively. Of the 3 potential probiotic LAB strains, intact cells of <I>L</I>. <I>paraplantarum</I> SC61 showed higher antioxidant activity, including DPPH radical scavenging, β-carotene bleaching inhibition, reducing power, superoxide anion scavenging, and ABTS radical scavenging activity. In addition, <I>L</I>. <I>paraplantarum</I> SC61 produced the most nitric oxide production and its mRNA expression level for iNOS, IL-1β, IL-6, and TNF-α were superior to those of <I>L</I>. <I>rhamnosus</I> GG. Therefore, <I>L. paraplantarum</I> SC61 was demonstrated to exhibit antioxidant and immunostimulatory activity and to have potential use as a probiotic product.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Lactobacillus paraplantarum</I> SC61 was isolated from <I>jangajji</I> under harsh conditions. </LI> <LI> <I>L. paraplantarum</I> SC61 showed high efficacy, safety, and stability. </LI> <LI> <I>L. paraplantarum</I> SC61 showed high antioxidant and immune-enhancing activity. </LI> <LI> <I>L. paraplantarum</I> SC61 could be used as a probiotic. </LI> </UL> </P>
Antimicrobial susceptibility of major bacterial pathogens in the equine genital tract
Kyoung-Yong Han,Hyoung-Seok Yang,Wan-choul Kang,Wongeun Son 한국예방수의학회 2019 예방수의학회지 Vol.43 No.1
Equine reproductive failures for many different reasons are the main contributors to economic losses in the horse industry. This paper describes major bacterial agents isolated from thoroughbred mares that had reproductive failures in the previous year as well as the antimicrobial susceptibility of these bacterial isolates. A total of 146 vaginal and uterine swab samples were submitted to Jeju Self-Governing Veterinary Research Institute by equine veterinarians from 2011 to 2015. Streptococcus equi subspecies zooepidemicus were the most frequently encountered bacteria in 29 samples (48.3%). Other identified species included 21 samples (35%) with Escherichia coli, six samples (10%) with Klebsiella pneumoniae, and four samples (6.7%) with Pseudomonas aeruginosa. All Streptococcus equi subsp. zooepidemicus isolates were sensitive to amoxicillin-clavulanic acid, cefazolin, cefuroxime, and florfenicol, while all were resistant to tetracycline and kanamycin. All E. coli were sensitive to enrofloxacin, ciprofloxacin, and sulfamethoxazole-trimethoprim, and most were susceptible to cefazolin, amoxicillin-clavulanic acid, cefuroxime, florfenicol, and gentamicin. All K. pneumoniae isolates were sensitive to amoxicillin-clavulanic acid, cefazolin, cefuroxime, florfenicol, and ciprofloxacin, while all were resistant to sulfamethoxazole-trimethoprim. P. aeruginosa exhibited sensitivity to quinolones and aminoglycosides, particularly gentamicin, while all were resistant to cefazolin and cefuroxime.