143,939 research outputs found
Using Qualitative Hypotheses to Identify Inaccurate Data
Identifying inaccurate data has long been regarded as a significant and
difficult problem in AI. In this paper, we present a new method for identifying
inaccurate data on the basis of qualitative correlations among related data.
First, we introduce the definitions of related data and qualitative
correlations among related data. Then we put forward a new concept called
support coefficient function (SCF). SCF can be used to extract, represent, and
calculate qualitative correlations among related data within a dataset. We
propose an approach to determining dynamic shift intervals of inaccurate data,
and an approach to calculating possibility of identifying inaccurate data,
respectively. Both of the approaches are based on SCF. Finally we present an
algorithm for identifying inaccurate data by using qualitative correlations
among related data as confirmatory or disconfirmatory evidence. We have
developed a practical system for interpreting infrared spectra by applying the
method, and have fully tested the system against several hundred real spectra.
The experimental results show that the method is significantly better than the
conventional methods used in many similar systems.Comment: See http://www.jair.org/ for any accompanying file
Time-Distance Imaging of Solar Far-Side Active Regions
It is of great importance to monitor large solar active regions in the
far-side of the Sun for space weather forecast, in particular, to predict their
appearance before they rotate into our view from the solar east limb. Local
helioseismology techniques, including helioseismic holography and
time-distance, have successfully imaged solar far-side active regions. In this
Letter, we further explore the possibility of imaging and improving the image
quality of solar far-side active regions by use of time-distance
helioseismology. In addition to the previously used scheme with four acoustic
signal skips, a five-skip scheme is also included in this newly developed
technique. The combination of both four- and five-skip far-side images
significantly enhances the signal-to-noise ratio in the far-side images, and
reduces spurious signals. The accuracy of the far-side active region imaging is
also assessed using one whole year solar observation.Comment: 13 pages, 5 figures, accepted by ApJ Letter
A low cost air hybrid concept
This article is a pre-print version of the full and final article which is available at the link below.Copyright © 2010 Institut français du pétrole
Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made
or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than IFP must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee: Request permission from Documentation, Institut français du pétrole, fax. +33 1 47 52 70 78, or [email protected] air hybrid engine absorbs the vehicle kinetic energy during braking, stores it in an air tank in the form of compressed air, and reuses it to propel a vehicle during cruising and acceleration. Capturing, storing and reusing this braking energy to give additional power can therefore improve fuel economy, particularly in cities and urban areas where the traffic conditions involve many stops and starts. In order to reuse the residual kinetic energy, the vehicle operation consists of 3 basic modes, i.e. Compression Mode (CM), Expander Mode (EM) and normal firing mode. Unlike previous works, a low cost air hybrid engine has been proposed and studied. The hybrid engine operation can be realised by means of production technologies, such as VVT and valve deactivation. In this work, systematic investigation has been carried out on the performance of the hybrid engine concept through detailed gas dynamic modelling using Ricardo WAVE software. Valve timing optimization has been done for the more efficient operation of air hybrid operation and obtaining higher braking and Motoring mean effective pressure for CM and EM respectively.EPSR
The Adverse Impact of Temperature on Income
Crop Production/Industries, Risk and Uncertainty,
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