2,291 research outputs found
Multiple Heat Exchangers Simulation Within the Newton-Raphson Framework
A general framework is proposed for simulating complex heat exchanger geometries in a manner suitable
for sequential solution of the refrigerant- and air-side equations for mass, momentum and energy. The sequential
solution enables the algorithm to be applied to a single module of a complex heat exchanger, and then integrated
with other modules within a simultaneous equation solver employing a Newton-Raphson approach. This report also
describes the integration of component subroutines into system simulation models for air conditioners and
refrigerators. The modular approach is illustrated by describing its application to a dual-evaporator refrigerator
simulation.Air Conditioning and Refrigeration Project 6
The Sheffield Wargames Corpus.
Recognition of speech in natural environments is a challenging task, even more so if this involves conversations between sev-eral speakers. Work on meeting recognition has addressed some of the significant challenges, mostly targeting formal, business style meetings where people are mostly in a static position in a room. Only limited data is available that contains high qual-ity near and far field data from real interactions between par-ticipants. In this paper we present a new corpus for research on speech recognition, speaker tracking and diarisation, based on recordings of native speakers of English playing a table-top wargame. The Sheffield Wargames Corpus comprises 7 hours of data from 10 recording sessions, obtained from 96 micro-phones, 3 video cameras and, most importantly, 3D location data provided by a sensor tracking system. The corpus repre-sents a unique resource, that provides for the first time location tracks (1.3Hz) of speakers that are constantly moving and talk-ing. The corpus is available for research purposes, and includes annotated development and evaluation test sets. Baseline results for close-talking and far field sets are included in this paper. 1
A semi-analytic meshfree method for Almansi–Michell problems of piezoelectric cylinders
AbstractSaint-Venant’s Problem, Almansi–Michell Problems, Meshfree Methods, Piezoelectricity. We present a semi-analytical method for analyzing prismatic nonhomogeneous piezoelectric cylinders with arbitrary cross-sectional geometry. The prescribed loads considered in this study include axial forces, torques, moments, and voltage resultants prescribed at the cylinder’s ends, as well as body forces, lateral surface shears, voltages, and pressures as long as they can be represented by a power series in the axial coordinate. This problem can be considered as an extension of Saint-Venant and Almansi–Michell problems for elastic bodies to piezoelectric bodies. In this computationally efficient method, the cross-sectional plane is discretized with a meshfree approach, and the solution is obtained analytically with respect to the axial coordinate. A number of examples are provided to demonstrate the veracity and utility of the proposed method
An application of recent developments of Data Envelopment Analysis to the evaluation of secondary schools in Portugal
This paper highlights the potentialities of Data Envelopment Analysis to evaluate the performance of organisations, using
the concept of super-efficiency - an extension of DEA which increases its performance - and presents an example from
the public sector to illustrate the method. The example selected is that of a school network where a place in a school can
be seen as a perishable good, as places which are not occupied during an academic year are wasted. Results for the
Portuguese Secondary school network show that the average efficiency of overcrowded schools, that is, those exceeding
their capacity, is lower than that of schools which are less crowded. This shows clearly that overcrowded schools, on
average, are less efficient in transforming their inputs into academic performance. It is this conviction, seldom proved
scientifically, which leads governments and international organisations to recommend planning criteria for public
facilities
Renormalizability of Massive Gravity in Three Dimensions
We discuss renormalizability of a recently established, massive gravity
theory with particular higher derivative terms in three space-time dimensions.
It is shown that this massive gravity is certainly renormalizable as well as
unitary, so it gives us a physically interesting toy model of perturbative
quantum gravity in three dimensions.Comment: 13 pages, no figure
Finite Density Algorithm in Lattice QCD -- a Canonical Ensemble Approach
I will review the finite density algorithm for lattice QCD based on finite
chemical potential and summarize the associated difficulties. I will propose a
canonical ensemble approach which projects out the finite baryon number sector
from the fermion determinant. For this algorithm to work, it requires an
efficient method for calculating the fermion determinant and a Monte Carlo
algorithm which accommodates unbiased estimate of the probability. I shall
report on the progress made along this direction with the Pad\'{e} - Z
estimator of the determinant and its implementation in the newly developed
Noisy Monte Carlo algorithm.Comment: Invited talk at Nankai Symposium on Mathematical Physics, Tianjin,
Oct. 2001, 18 pages, 3 figures; expanded and references adde
Gravitational Corrections to the Energy-Levels of a Hydrogen Atom
The first order perturbations of the energy levels of a hydrogen atom in
central internal gravitational field are investigated. The internal
gravitational field is produced by the mass of the atomic nucleus. The energy
shifts are calculated for the relativistic 1S, 2S, 2P, 3S, 3P, 3D, 4S and 4P
levels with Schwarzschild metric. The calculated results show that the
gravitational corrections are sensitive to the total angular momentum quantum
number.Comment: 7 page
Situational Voluntary Compliance: Adherence to COVID-19 Social Distancing Guidelines in the 2020 Local Outbreak in Beijing
To mitigate the COVID-19 pandemic many countries have adopted mandatory social distancing measures, but in China, social distancing was implemented only as an advisory guideline. This article seeks to understand whether, and why Chinese citizens adhered to such social distancing advice. The data, derived from a survey in the 2020 local outbreak in Beijing, show that voluntary compliance was hardly influ-enced by motivational predictors, but was almost exclusively dependent on a single, key situational predictor, namely people’s practical capacity to follow social distancing. These findings demonstrate that the emphasis on intrinsic and extrinsic motivations in existing compliance research does not do justice to the situational nature of voluntary compliance observed within this particular context. We discuss theoretical implications of these findings for the compliance literature. Moreover, we use these findings to provide (tentative) insight into the compliance challenges that China was facing during the course of the pandemic, and to speculate about ways in which compliance may be enhanced during future pandemic outbreaks in China.</p
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