475 research outputs found

    FFTPL: An Analytic Placement Algorithm Using Fast Fourier Transform for Density Equalization

    Full text link
    We propose a flat nonlinear placement algorithm FFTPL using fast Fourier transform for density equalization. The placement instance is modeled as an electrostatic system with the analogy of density cost to the potential energy. A well-defined Poisson's equation is proposed for gradient and cost computation. Our placer outperforms state-of-the-art placers with better solution quality and efficiency

    Service Quality and Queue

    Get PDF
    While active buyers can bring a firm stable income, their perceptions of service quality can help the firm improve its service. This investigation identifies five factors that influence service quality for queuing customers. This investigation also identifies the causality relationships among five factors that influence service quality. Tangibility and responsiveness should be foci for a service company hoping to change customer perceptions to service quality. Tangibility directly enhances responsiveness and assurance. Tangibility indirectly enhances reliability and empathy. Moreover, responsiveness enhances assurance and empathy. Responsiveness directly enhances reliability. Through enhancing responsiveness and tangibility, customers should develop good feelings regarding service quality

    Changes in Outcome and Complication Rates of Very-low-birth-weight Infants in One Tertiary Center in Southern Taiwan Between 2003 and 2010

    Get PDF
    BackgroundNeonatal intensive care has changed dramatically over the past few decades and the survival of infants has generally improved in many countries. The purpose of this study was to explore the recent evolution of mortality and morbidities among very-low-birth-weight (VLBW) infants in southern Taiwan.MethodsWe retrospectively reviewed the medical records of VLBW (birth weight <1500 g) infants who were admitted to a neonatal intensive care unit at a tertiary medical center in southern Taiwan from 2003 to 2010. The study period was divided into two cohorts: the first cohort of 2003–2006 and the second cohort of 2007–2010. Demographic profiles and complications were recorded, including the following information: sex, birth body weight (BBW), gestational age (GA), Apgar score, patent ductus arteriosus (PDA), necrotizing enterocolitis, retinopathy, chronic lung disease (CLD), inguinal hernia, and sepsis. The length of stay (LOS) in hospital was compared between the two cohorts.ResultsA total of 420 (212 male) VLBW infants were enrolled with 52 (12.4%) deaths. Compared to surviving infants, deceased infants had significantly lower GA, Apgar scores, and BBW. The mortality of VLBW infants remained static between the two birth cohorts, but the incidence of major morbidities generally decreased. The LOS for overall surviving infants and the proportion of LOS > 60 days were both reduced in the period of 2007–2010. With further stratification by BBW, the major reduction of long LOS was only found in the group of BBW ≥ 1000 g. The multivariate logistic regression model found PDA, CLD, and BBW < 1000 g were major complications to be associated with long LOS among surviving infants.ConclusionPeriodic evaluation of the mortality and morbidity of preterm infants can help to understand the changes and trends of our neonatal care. Further study using the national dataset to provide more representative information is warranted

    Membrane Transport Mechanisms Probed by Capacitance Measurements With Megahertz Voltage Clamp

    Get PDF
    We have used capacitance measurements with a 1-Âľs voltage clamp technique to probe electrogenic ion-transporter interactions in giant excised membrane patches, The hydrophobic ion dipicrylamine was used to test model predictions for a simple charge-moving reaction. The voltage and frequency dependencies of the apparent dipicrylamine-induced capacitance, monitored by 1-mV sinusoidal perturbations, correspond to single charges moving across 76% of the membrane field at a rate of 9500 s^(-1) at 0 mV. For the cardiac Na,K pump, the combined presence of cytoplasmic ATP-and sodium induces an increase of apparent membrane capacitance which requires the presence of extracellular sodium, The dependencies of capacitance changes on frequency, voltage, ATP, and sodium verify that phosphorylation enables a slow 300- to 900-s^(-1), pump transition (the E_1-E_2 conformational change), which in turn enables fast, electrogenic, extracellular sodium binding reactions, For the GAT1 (y-aminobutyric acid,Na,Cl) cotransporter, expressed in Xenopus oocyte membrane, we find that chloride binding from the cytoplasmic side, and probably sodium binding from the extracellular side, results in a decrease of membrane capacitance monitored with 1- to 50-kHz perturbation frequencies. Evidently, ion binding by the GAT1 transporter suppresses an intrinsic fast charge movement which mag originate from a mobility of charged residues of the transporter binding sites. The results demonstrate that fast capacitance measurements can provide new insight into electrogenic processes closely associated with ion binding by membrane transporters
    • …
    corecore