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基于切换仿射线性模型的三相APF电流控制方法  [PDF]
郭晓云,刘会金,曹玉胜
中国电机工程学报 , 2011,
Abstract: 提出一种基于切换仿射线性模型和切换系统全局稳定理论的三相有源电力滤波器(activepowerfilter,APF)电流控制方法。该方法首先建立了任意运行点下的三相APF的切换仿射线性系统模型,再根据凸组合稳定条件,将一个工频周期按三相母线电压大小划分为12个区间,在每个区间内设定能满足二次稳定条件的开关子系统组合,并为系统选取共同的李亚普诺夫(Lyapunov)函数,基于切换系统理论控制方法的设计思路,提出了建立在切换仿射线性模型基础上的二次稳定控制策略。最后进行了仿真分析并验证其可行性。
A characterization of strictly APF extensions  [PDF]
Bryden Cais,Christopher Davis,Jonathan Lubin
Mathematics , 2014,
Abstract: Let K denote a finite extension of Qp. We give necessary and sufficient conditions for an infinite totally wildly ramified extension L/K to be strictly APF in the sense of Fontaine-Wintenberger. Our conditions are phrased in terms of the existence of a certain tower of intermediate subfields. These conditions are well-suited to producing examples of strictly APF extensions, and in particular, our main theorem proves that the phi-iterate extensions previously considered by the first two authors are strictly APF.
基于改进仿射投影算法的数字助听器自适应回声消除
Acoustic Feedback Cancellation Based on Improved Affine Projection Algorithm for Hearing Aids
 [PDF]

秦海娟,张玲华
- , 2015, DOI: 10.16337/j.1004-9037.2015.02.017
Abstract: 提出了一种改进的仿射投影算法。该算法建立了步长因子与误差能量之间一种新的非线性函数关系,根据误差能量的变化自动调整步长因子,以达到加快滤波器收敛速度、降低稳态失调的目的;在对误差能量的估计中提出了遗忘因子选择规则,提高了误差能量估计的准确性。对提出的算法进行的数学分析,为其快速收 敛性提供了理论依据。实验仿真表明,与传统的自适应算法以及固定步长的仿射投影算法相比,提出的改进仿射算法在收敛速度、稳态失调等方面有明显改善。
An improved affine projection algorithm for hearing aids is proposed to increase the convergence speed and reduce the misalignmengt. The algorithm establishes a new nonlinear function between the step-size and the estimation error. The step-size of the proposed algorithm is adjusted automatically according to the change of the estimation error, which leads to high convergence speed and low misalignment. In order to improve the accuracy of estimating the power of error, a rule for selecting forgetting factor is proposed. Mathematical analysis provides theoretical basis for its outstanding capacity of converging to the objective system. The simulation results show that the proposed algorithm achieves faster convergence speed and lower final misalignment compared with traditional adaptive methods and fixed step-size affine projection algorithm.
浅析三异涤长丝仿毛织物的技术关键  [PDF]
纺织学报 , 1999,
Abstract: 本文简析了三异涤长丝仿毛织物开发过程,发现仿毛织物的研制与开发是一项系统工程,其中三异涤长丝、织造形式以及合理的碱减量技术是仿毛织物成功的技术关键。
Effect of APF Gel on the Micro Hardness of Sealant Materials
Masoumeh Moslemi,Sepideh Khlili,Mohammad M. Shadkar,Amir Ghasemi,Nikoo Tadayon
Research Journal of Biological Sciences , 2012,
Abstract: The possible adverse effects of topical fluoride treatment on restorative materials have been the subject of many studies during the last decades. Since, APF gels and sealant materials have many possibilities to interact in the oral cavity, it is necessary to understand such interaction. The aim of this study was to evaluate the effect of APF gel (Sultan) on the microhardness of a filled sealant material (Helioseal F) and an unfilled sealant material (Clinpro). A total of 16 cylindrical specimens (6 mm diameter and 2 mm thickness) from each material were fabricated and stored in distilled water at 37°C for 48 h. Half of the specimens were assigned as the control group and stored in distilled water for the corresponding periods of the fluoridation experiments. For the remaining half, the specimens were treated with 1.23% APF gel for 4 min. The application was followed by removing the gel and storing for 30 min in artificial saliva. Subsequently the specimens were immersed in distilled water for 30 min. The process of APF application was repeated. Vickers microhardness of each specimen was assessed and the results were analyzed using paired t-test (p<0.05). Statistical analysis showed no statistically significant difference between the microhardness values of Helioseal F following APF treatment and controls (11.43±2.35 vs. 12.79±2.16). The microhardness of Clinpro was significantly reduced by exposure to APF gel (11.01±0.89 vs. 12.95±1.52). It seems filled sealants may be a better choice in respect to microhardness, when topical Acidulated Phosphate Fluoride (APF) gel is to be used routinely.
APF - The Lick Observatory Automated Planet Finder  [PDF]
Steven S. Vogt,Matthew Radovan,Robert Kibrick,R. Paul Butler,Barry Alcott,Steve Allen,Pamela Arriagada,Mike Bolte,Jennifer Burt,Jerry Cabak,Kostas Chloros,David Cowley,William Deich,Brian Dupraw,Wayne Earthman,Harland Epps,Sandra Faber,Debra Fischer,Elinor Gates,David Hilyard,Brad Holden,Ken Johnston,Sandy Keiser,Dick Kanto,Myra Katsuki,Lee Laiterman,Kyle Lanclos,Greg Laughlin,Jeff Lewis,Chris Lockwood,Paul Lynam,Geoffrey Marcy,Maureen McLean,Joe Miller,Tony Misch,Michael Peck,Terry Pfister,Andrew Phillips,Eugenio Rivera,Dale Sandford,Mike Saylor,Richard Stover,Matthew Thompson,Bernie Walp,James Ward,John Wareham,Mingzhi Wei,Chris Wright
Physics , 2014, DOI: 10.1086/676120
Abstract: The Automated Planet Finder (APF) is a facility purpose-built for the discovery and characterization of extrasolar planets through high-cadence Doppler velocimetry of the reflex barycentric accelerations of their host stars. Located atop Mt. Hamilton, the APF facility consists of a 2.4-m telescope and its Levy spectrometer, an optical echelle spectrometer optimized for precision Doppler velocimetry. APF features a fixed format spectral range from 374 nm - 970 nm, and delivers a "Throughput" (resolution * slit width product) of 114,000 arc-seconds, with spectral resolutions up to 150,000. Overall system efficiency (fraction of photons incident on the primary mirror that are detected by the science CCD) on blaze at 560 nm in planet-hunting mode is 15%. First-light tests on the RV standard stars HD 185144 and HD 9407 demonstrate sub-meter per second precision (RMS per observation) held over a 3-month period. This paper reviews the basic features of the telescope, dome, and spectrometer, and gives a brief summary of first-light performance.
APF和SVC联合运行的稳定控制  [PDF]
邓礼宽,姜新建,朱东起,陈峻岭
电力系统自动化 , 2005,
Abstract: 研究了有源电力滤波器(APF)和静止无功补偿器(SVC)联合运行中的互相影响问题,指出在两者同时运行的情况下SVC控制器的设计要考虑到APF的影响,否则系统可能会不稳定。通过分析APF对SVC的影响途径,指出APF采用通常的Ip-Iq检测方法时,与SVC的耦合程度大;而采用“补偿特定次数谐波”方法时,与SVC的耦合程度小,此时APF是否投入对系统的稳定性基本没有影响,因此提高了系统可靠性。
Effect of APF gel application time on enamel demineralization and fluoride uptake in situ
Villena, Rita Sarmiento;Tenuta, Livia Maria Andaló;Cury, Jaime Aparecido;
Brazilian Dental Journal , 2009, DOI: 10.1590/S0103-64402009000100006
Abstract: this in situ crossover and blind study was conducted to investigate the effect of professional acidulated phosphate fluoride (apf) gel application time on the subsequent inhibition of enamel demineralization. during 3 phases of 28 days each, 15 volunteers wore palatal appliances containing 4 enamel blocks, which were subjected to 3 treatment groups: not treated (control) and pre-treated with apf gel for 1 or 4 min. dental plaque was allowed to accumulate on the blocks and the appliances were immersed in 10% sucrose solution 3 times a day simulating a cariogenic challenge. after each phase, the blocks were removed to evaluate enamel demineralization and concentration of fluoride (f) remaining after the cariogenic challenge. f formed on enamel was determined in additional enamel blocks subjected only to apf gel application. apf gel was efficient in reducing enamel demineralization (p<0.05), irrespective of the application time (p>0.05). also, the concentration of the f formed and retained on enamel was significantly higher after apf gel application (p<0.05), but the effect of time of application was not statistically significant (p>0.05). the results suggest that apf application for either 1 or 4 min is equally efficient to increase f concentration in enamel and reduce enamel demineralization.
Interstitial cystitis antiproliferative factor (APF) as a cell-cycle modulator
Hani H Rashid, Jay E Reeder, Mary J O'Connell, Chen-Ou Zhang, Edward M Messing, Susan K Keay
BMC Urology , 2004, DOI: 10.1186/1471-2490-4-3
Abstract: Explant cultures from normal bladder biopsy specimens were exposed to APF or mock control. DNA cytometry was performed using an automated image analysis system. Cell cycle phase fractions were calculated from the DNA frequency distributions and compared by two-way analysis of variance (ANOVA).APF exposure produced statistically significant increases in the proportion of tetraploid and hypertetraploid cells compared to mock control preparations, suggesting a G2 and/or M phase cell cycle block and the production of polyploidy.APF has a specific effect on cell cycle distributions. The presence of a peptide with this activity may contribute to the pathogenesis of interstitial cystitis through disruption of normal urothelial proliferation and repair processes.Interstitial cystitis (IC) is a chronic bladder disorder presenting with long-term symptoms of round-the-clock urinary frequency and/or pain in the absence of any other reasonable causation [1]. Although there are multiple hypotheses on the primary cause of IC [2-7], it remains a clinical enigma since there are no definitive data to support these theories [2-7]. A recent breakthrough in IC research has been the discovery of antiproliferative factor (APF) and its association with IC [8]. APF, a peptide purified from the urine of IC patients has been shown to decrease incorporation of thymidine by bladder epithelial cells, decrease levels of urinary heparin-binding epidermal growth factor-like growth factor (HB-EGF) and increase levels of epidermal growth factor (EGF) in vitro which reflects altered levels of these growth factors seen in IC patients [9,10]. Studies to characterize APF at the molecular level are on-going. To date, the activity corresponds to a single HPLC peak which contains a peptide with a molecular weight less than 3,000 Dalton [10]. Additionally, urine APF activity is found at a higher level in IC vs. non-IC patients [11]. APF is a reliable marker of IC and may be an important factor in the pathoge
分题选择完型填空与集库式完型填空的对比实验  [PDF]
何莲珍
浙江大学学报(人文社会科学版) , 1999,
Abstract: ?完型填空是一种被许多大规模考试所广泛采用的题型,但对于这种题型的研究在国内却很少。本文在对完型填空进行综合概述的基础上,对两种操作性很强的完型填空形式,即分题选择完型填空与集库式完型填空,作了对比研究,结果表明前者与词汇语法测试的相关较高,而后者与阅读理解测试的相关很高,从而证明集库式完型填空是一种具有较高效率的阅读理解测试方式。
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