9,878 research outputs found
LANDSAT-4 multispectral scanner (MSS) subsystem radiometric characterization
The multispectral band scanner (mass) and its spectral characteristics are described and methods are given for relating video digital levels on computer compatible tapes to radiance into the sensor. Topics covered include prelaunch calibration procedures and postlaunch radiometric processng. Examples of current data resident on the MSS image processing system are included. The MSS on LANDSAT 4 is compared with the scanners on earlier LANDSAT satellites
The gravitational path integral and trace of the diffeomorphisms
I give a resolution of the conformal mode divergence in the Euclidean
gravitational path-integral by isolating the trace of the diffeomorphisms and
its contribution to the Faddeev-Popov measure.Comment: 20 pgs
Entropic Origin of the Growth of Relaxation Times in Simple Glassy Liquids
Transitions between ``glassy'' local minima of a model free-energy functional
for a dense hard-sphere system are studied numerically using a
``microcanonical'' Monte Carlo method that enables us to obtain the transition
probability as a function of the free energy and the Monte Carlo ``time''. The
growth of the height of the effective free energy barrier with density is found
to be consistent with a Vogel-Fulcher law. The dependence of the transition
probability on time indicates that this growth is primarily due to entropic
effects arising from the difficulty of finding low-free-energy saddle points
connecting glassy minima.Comment: Four pages, plus three postscript figure
Stability of the Breached Pair State for a Two-species Fermionic System in the Presence of Feshbach Resonance
We investigate the phenomenon of fermionic pairing with mismatched Fermi
surfaces in a two-species system in the presence of Feshbach resonance, where
the resonantly-paired fermions combine to form bosonic molecules. We observe
that the Feshbach parameters control the critical temperature of the gapped BCS
superfluid state, and also determine the range over which a gapless breached
pair state may exist. Demanding the positivity of the superfluid density, it is
shown that although a breached pair state with two Fermi surfaces is always
unstable, its single Fermi-surface counterpart can be stable if the chemical
potentials of the two pairing species have opposite signs. This condition is
satisfied only over a narrow region in the BEC side, characterized by an upper
and a lower limit for the magnetic field. We estimate these limits for a
mixture of two hyperfine states of Li using recent experimental data.Comment: 14 pages,5 figure
The resummed thrust distribution in DIS
We present preliminary results on the resummation of leading and
next-to-leading logarithms for the thrust distribution in deep inelastic
scattering. Our predictions, expanded to O(alpha_s^2), are compared to
corresponding results from the Monte Carlo programs DISASTER++ and DISENT.Comment: 5 pages; talk presented by V. Antonelli at the UK Phenomenology
Workshop on Collider Physics, September 1999, St. John's College, Durha
Comparative investigation of the coupled-tetrahedra quantum spin systems Cu2Te2O5X2, X=Cl, Br and Cu4Te5O12Cl4
We present a comparative study of the coupled-tetrahedra quantum spin systems
Cu2Te2O5X2, X=Cl, Br (Cu-2252(X)) and the newly synthesized Cu4Te5O12Cl4
(Cu-45124(Cl)) based on ab initio Density Functional Theory calculations. The
magnetic behavior of Cu-45124(Cl) with a phase transition to an ordered state
at a lower critical temperature T=13.6K than in Cu-2252(Cl) (T=18K) can
be well understood in terms of the modified interaction paths. We identify the
relevant structural changes between the two systems and discuss the
hypothetical behavior of the not yet synthesized Cu-45124(Br) with an ab initio
relaxed structure using Car-Parrinello Molecular Dynamics.Comment: 2 pages, 1 figure; submitted to Proceedings of M2S-HTSC VIII, Dresden
200
Identification of Risk Factors in Globally Outsourced Software Projects using Logistic Regression and ANN
Abstract Global supply chains are often critically dependent upon globally outsourced Information Technology (IT) and Business Process Outsourcing (BPO) projects. Effective risk assessment and mitigation of these projects is therefore of great importance for such supply chains. Traditional risk management techniques used so far in IT and BPO projects have depended almost entirely on the Expected Utility Theory that computes risk exposure as the product of risk probability and risk impact. Although this method is considered the gold standard in risk assessment, it has severe limitations due to the fact that accurate computation of risk probability and impact is difficult. In this and earlier papers, we have advocated the use of risk factors in conjunction with other existing methods for risk assessment. Risk factors are conditions that affect project performance. In this paper, we use Logistic Regression and Artificial Neural Network (ANN) based methods on a set of globally outsourced projects to predict project performance and to rank the relative importance of project risk factors. Although in this paper these techniques have been tested in outsourced IT projects, these can also be used in identifying and determining project risk factors in other industries. Keywords Outsourced projects, Risk Management, Risk Factors, Logistic Regression, Artificial Neural Network
Extended Self-similarity in Kinetic Surface Roughening
We show from numerical simulations that a limited mobility solid-on-solid
model of kinetically rough surface growth exhibits extended self-similarity
analogous to that found in fluid turbulence. The range over which
scale-independent power-law behavior is observed is significantly enhanced if
two correlation functions of different order, such as those representing two
different moments of the difference in height between two points, are plotted
against each other. This behavior, found in both one and two dimensions,
suggests that the `relative' exponents may be more fundamental than the
`absolute' ones.Comment: 4 pages, 4 postscript figures included (some changes made according
to referees' comments. accepted for publication in PRE Rapid Communication
Spatiotemporal rheochaos in nematic hydrodynamics
Motivated by the observation of rheochaos in sheared wormlike micelles
[Bandyopadhyay et al., Phys. Rev. Lett, 84 2022, (2000); Europhys. Lett. 56,
447 (2001); Pramana 53, 223 (1999)] we study the coupled nonlinear partial
differential equations for the hydrodynamic velocity and order parameter fields
in a sheared nematogenic fluid. In a suitable parameter range, we find
irregular, dynamic shear-banding and establish by decisive numerical tests that
the chaos we observe in the model is spatiotemporal in nature.Comment: Slight changes in text, references and Fig. 5 inset; 6 eps figures
(figs 2,3,4 at lower resolution to reduce file size; full files available on
request); accepted for publication in Phys Rev Let
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