4,330 research outputs found
On using Directional Information for Parameter Space Decomposition in Ellipse Detection
No full textIn this paper we use the parametric polar representation to extend the application of edge directional information from circle to ellipse extraction. As a result we obtain a mapping which decomposes the parameter space required for ellipse extraction into two independent sub-spaces and one final histogram accumulator. The mapping includes the tangent of the angle of the first and second directional derivatives. These tangents are computed by considering edge direction at two border points. We show that the use of gradient information for parameter space decomposition avoids the intensive point labelling imposed by geometric constraints used by other approaches
Large-scale patterns in turbulent Rayleigh-Bénard convection in very large aspect ratio cells
No full textLarge-scale patterns, which are well-known from the spiral defect chaos regime of thermal convection at Rayleigh numbers Ra 105. They are uncovered when the turbulent fields are averaged in time and turbulent fluctuations are thus removed. We apply the Boussinesq closure to calculate turbulent viscosities and diffusivities, respectively. The resulting turbulent Rayleigh number Ra_, that describes the convection of the mean patterns, is indeed in the spiral defect chaos range. Interestingly, the turbulent Prandtl numbers are smaller than one with 0:2 _ Pr_ _ 0:4 for Prandtl numbers 0:7 _ Pr _ 10. Finally, we demonstrate that these mean flow patterns are robust to an additional finite-amplitude side wall-forcing when the level of turbulent fluctuations in the flow is sufficiently high
Reynolds number effect on 3D turbulent offset jet reattaching to a free surface
No full textExperimental study was carried out to investigate the effect of Reynolds number on 3D offset jet reattaching to above free surface. Sharp edged square nozzle was used to produce the jets, and the measurements were performed at the following six different Reynolds numbers: 2300, 3700, 5100, 7900, 10300 and 11900. Detailed velocity measurements were made in the symmetry plane. From the PIV data, the mean velocity and turbulence statistics were obtained to study the effects of Reynolds number on the salient features of the jet flow. Preliminary results on streamwise mean velocity decay along the nozzle centerline, contours of streamwise mean velocity and Reynolds shear stress are presented herein
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
A 0.45 V low power high PSRR subthreshold CMOS voltage reference
No full textUniversity of Minnesota M.S. thesis. October 2017. Major: Electrical/Computer Engineering. Advisor: Ted Higman. 1 computer file (PDF); viii, 51 pages.Voltage references are broadly used in analog and digital systems to generate a DC voltage independent of process, supply voltage and temperature (PVT) variations. Conventional band gap references (BGR) add the forward bias voltage across a PN junction with a voltage that is proportional to absolute temperature to produce an output that is insensitive to changes in temperature. BGRs generate a nearly temperature independent reference, of about 1.25 V, and therefore they require a higher supply voltage, which might not meet the low voltage constraints for low-power applications such as passive RFID’s, wearable and implantable medical devices. Also, BGRs use resistors that need more area on silicon. One possible solution to meet the low power requirement is to operate MOSFETs in subthreshold region. Most often, forward biased PN-junctions of BGRs are substituted with MOSFETs biased in the subthreshold region and achieves a supply voltage down to 0.6 V.\par This paper presents a sub-1V voltage reference circuit that has only MOS transistors, all working in subthreshold region with a supply voltage down to 0.45 V and a supply current of 1nA at room temperature for ultra-low power applications. The circuit is designed and simulated in 0.13um technology.Palamedu Sundaram, Prakash. (2017). A 0.45 V low power high PSRR subthreshold CMOS voltage reference. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/209177
<i>Entrenchment, wealth, power, and the constitution of democratic societies</i> by Paul Starr
No full textEntrenchment, Wealth, Power, and the Constitution of Democratic Societies, by Paul Starr, New Haven, CT: Yale University Press. 2019. 280 pages, hardcover.Why should we, as Management scholars and educators, care about a book on political diagnosis? The answer is twofold. First, the calibre of the author (Paul Starr), an awardee of both Bancroft and Pulitzer Prizes, a former policy advisor to the Clinton administration, and the author of The Transformation of American Medicine (1982), a book with a profound impact on American policy circles. Second, the core concept (entrenchment) of the book, and its potential to advance the process of institutional development, and the ways in which we can reform and change our institutions to better meet the current and pressing needs of the many, rather than preserve the unequal privileges of a few. In light of the geopolitical, social, and environmental pressures we see currently rising across the world (George, Howard-Grenville, Joshi & Tihanyi, 2016; Howard-Grenville, Buckle, Hoskins & George, 2014) there is no better time to examine whether and how we can address some of these grand challenges by reforming and improving our institutions
M.S. Kutorga and V.M. Vedrov: Conflict of Teacher and Student
No full textВ статье рассматривается конфликт между М.С. Куторгой и его учеником В.М. Ведровым. Исследуются причины конфликта, а также то влияние, которое он оказал на дальнейшую научную карьеру ученика. This article discusses the conflict between M.S. Kutorga and his student V.M. Vedrov. The author investigates the causes of the conflict and its impact on academic career V.M. Vedrov
Ultra-fast escape of a deformable jet-propelled body
No full textIn this work a cephalopod-like deformable body that fills an internal cavity with fluid and expels it to propel an escape manoeuvre, while undergoing a drastic external shape change through shrinking, is shown to employ viscous as well as mainly inviscid hydrodynamic mechanisms to power an impressively fast start. First, we show that recovery of added-mass energy enables a shrinking rocket in a dense inviscid flow to achieve greater escape speed than an identical rocket in a vacuum. Next, we extend the shrinking body results of Weymouth & Triantafyllou (J. Fluid Mech., vol. 702, 2012, pp. 470–487) to three-dimensional bodies and show that three hydrodynamic mechanisms must be combined to achieve rapid escape performance in a viscous fluid: added-mass energy recovery; flow separation elimination; and an optimized energy storage and recovery. In particular, we show that the mechanism of separation elimination achieved through rapid body shrinking, coordinated with the mechanism of recovering the initially imparted added-mass energy, is critical to achieving a high escape speed. Hence a flexible, collapsing body can be vastly superior to a rigid-shell jet-propelled body
The Debate on the Poverty Estimates of 1999–2000
No full textThis paper compares the latest estimates of poverty (19992000) made by the Planning Commission with earlier estimates of the 1980s and 1990s, focusing on the methodology and database used for estimation. It extensively reviews the attempts by Angus Deaton (2003a, b, and c), Sundaram and Tendulkar (2001; 2003a, d), Sen-Himanshu (2004a, b) and Surjit Bhalla (2003) in this regard. The paper traces the comparable poverty estimates for the 1980s and 1990s in their levels and change and uses the extent of poverty reduction implicit in these estimates to assess the magnitude of poverty reduction in the two decades. These are placed in the wider debate on the impact of the economic reform programmes on the incidence of poverty in the Indian context.India, poverty estimates
AIEDAM thematic collection: a perspective on data-enabled design – design meet data science
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Internet of ThingsDesign, Organisation and Strateg
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