74,952 research outputs found
The Benefits of Being Economics Professor A (and not Z)
No full textAlphabetic name ordering on multi-authored academic papers, which is the convention in the economics discipline and various other disciplines, is to the advantage of people whose last name initials are placed early in the alphabet. As it turns out, Professor A, who has been a first author more often than Professor Z, will have published more articles and experienced afaster growth rate over the course of her career as a result of reputation and visibility. Moreover, authors know that name ordering matters and indeed take ordering seriously: Several characteristics of an author group composition determine the decision to deviate from the default alphabetic name order to a significant extent.performance measurement, incentives, economists, name ordering
Z-source inverter topologies with switched Z-impedance networks: A review
No full textThe Z‐source inverter is one of the most interesting power electronic converters. Over the past decades, research and development have been in high demand to meet the challenges for improving the converter performance with reduced weight and cost while having high efficiency along with high gain or boost factor. Since the inception, tons of resolutions, customizations, and improvements have appeared to achieve these performance goals. To overcome the most common drawback, i.e. the low boost factor of classical Z‐source inverters, the switched inductor/capacitor and switched boost Z‐source inverter topologies have become predominant in the recent epoch. Furthermore, the higher component voltage stress, discontinuous input current, and high inrush start‐up current issues have also been addressed and solved in various literature as part of this topical advancement. In this study, a comprehensive review of various switched impedance network‐based Z‐source inverter topologies has been accomplished for providing a quick report to researchers and engineers so that they can consider this as a one‐stop solution for selecting inverters from this group. The overall study covers the methodology, features, and relevant important results of the latest switched Z‐source inverter models in order to demonstrate the coordination between pitfalls and improvements
Final word on Jersey Dutch
No full textIn this article, William Z. Shetter compares and contrasts the dialects that developed between different Dutch colonies in the New World. He explores in-depth the nuances of Jersey Dutch, and provides theories to explain how Dutch and colonial languages blended. The article is reprinted from American Speech, December 1958, Volum XXXIII, No. 4
MODELING AND ANALYSIS OF A SWITCHED INDUCTOR ASSISTED MODIFIED Z-SOURCE INVERTER
No full textZ-source inverter (ZSI) has become an attractive replacement for the voltage source
inverter in the conventional dual-stage power conditioning system (PCS)
Z-source inverter topologies with switched Z-impedance networks:A review
No full textThe Z-source inverter is one of the most interesting power electronic converters. Over the past decades, research and development have been in high demand to meet the challenges for improving the converter performance with reduced weight and cost while having high efficiency along with high gain or boost factor. Since the inception, tons of resolutions, customizations, and improvements have appeared to achieve these performance goals. To overcome the most common drawback, i.e. the low boost factor of classical Z-source inverters, the switched inductor/capacitor and switched boost Z-source inverter topologies have become predominant in the recent epoch. Furthermore, the higher component voltage stress, discontinuous input current, and high inrush start-up current issues have also been addressed and solved in various literature as part of this topical advancement. In this study, a comprehensive review of various switched impedance network-based Z-source inverter topologies has been accomplished for providing a quick report to researchers and engineers so that they can consider this as a one-stop solution for selecting inverters from this group. The overall study covers the methodology, features, and relevant important results of the latest switched Z-source inverter models in order to demonstrate the coordination between pitfalls and improvements
Fiscal Deficit cannot be reduced by increasing Taxes (A point to ponder from Pakistan)
No full textIn Pakistan the budget deficits have consistently at increasing trend from 1995 to onwards which is being financed by the governments of now and then through external and domestic borrowing which are resulting a high debt levels due to high interest cost associated with it and this all pave the way for an increase in forthcoming taxes levy by the government time to time. This paper is an empirical investigation of the proposition that Fiscal deficit cannot be reduced by increasing taxes. The finding reveals that an increase in taxes is not the better choice for tackling the jinni of fiscal deficit.Fiscal deficit, Tax Collection, Error correction model (ECM), ADF unit root test
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Statistics of the subgrid scales after the shock-turbulence interaction
No full textThe interaction of a normal shock with isotropic turbulence (IT) represents a basic problem for studying some of the phenomena associated with high speed flows, such as hypersonic flight, supersonic combustion and Inertial Confinement Fusion (ICF). In general, in practical applications, the shock width is much smaller than the turbulence scales and the upstream turbulent Mach number is modest. In this case, recent high resolution shock-resolved Direct Numerical Simulations (DNS) (Ryu and Livescu, J. Fluid Mech., 756, R1, 2014) show that the interaction can be described by the Linear Interaction Approximation (LIA). By using LIA to alleviate the need to solve the shock, DNS post-shock data can be generated at much higher Reynolds numbers than previously possible. Here, such results with Taylor Reynolds number around are used to investigate the properties of the subgrid scales (SGS). In particular, it is shown that the shock interaction decreases the asymmetry of the SGS dissipation PDF as the shock Mach number increases, with a significant enhancement in size of the regions and magnitude of backscatter
New symmetric enhanced-boost modified Z-source inverters with switched Z-impedance
No full textIn this paper, two new symmetric structures are proposed to modify existing enhanced-boost Z-source inverter (EB-ZSI) by employing the same number of components in the Z-impedance network. The Z-impedance network in the first structure is connected in parallel with H-bridge circuit to form a topology called, enhanced-boost modified Z-source inverter (EBM-ZSI) while the second topology is named as improved EBM-ZSI (iEBM-ZSI) where Z impedance network is connected in series to H-bridge circuit. The proposed structures or topologies exhibit less capacitor voltage stresses on their impedance networks and input start-up inrush current for a similar boost factor and voltage gain to that of an EB-ZSI. The proposed iEBM possesses a common ground feature along with the improved performance in terms of reducing both the capacitor voltage stress and input start-up inrush current as compared to both EBM-ZSI and EB-ZSI. This paper presents some analyses to support these claims and simulation studies are carried out to further strengthen the analytical results
- …
