3,341 research outputs found
Nonlinear internal models for output regulation
In this paper we show how nonlinear internal models can be effectively used
in the design of output regulators for nonlinear systems. This result provides
a significant enhancement of the non-equilibrium theory for output regulation,
which we have presented in the recent paper entitled "Limit Sets, Zero
Dynamics, and Internal Models in the Problem of Nonlinear Output Regulation"
Maternal Characteristics and Child Problem Behaviors: A Comparison of Foster and Biological Mothers
The purpose of this exploratory study was to compare the parenting behavior, stress and support of foster mothers and biological mothers of young children. A sample of 60 mothers of young children (30 foster mothers, 30 biological mothers) completed measures of parenting behavior, parenting stress, child problem behaviors, and perceived social support. Findings indicated that biological mothers were single and younger than foster mothers. In addition, biological mothers utilized more verbal and corporal discipline than foster mothers, experienced greater parental distress and received less social support for their parenting. Implications of these findings are discussed
Simulating lattice gauge theories on a quantum computer
We examine the problem of simulating lattice gauge theories on a universal
quantum computer. The basic strategy of our approach is to transcribe lattice
gauge theories in the Hamiltonian formulation into a Hamiltonian involving only
Pauli spin operators such that the simulation can be performed on a quantum
computer using only one and two qubit manipulations. We examine three models,
the U(1), SU(2), and SU(3) lattice gauge theories which are transcribed into a
spin Hamiltonian up to a cutoff in the Hilbert space of the gauge fields on the
lattice. The number of qubits required for storing a particular state is found
to have a linear dependence with the total number of lattice sites. The number
of qubit operations required for performing the time evolution corresponding to
the Hamiltonian is found to be between a linear to quadratic function of the
number of lattice sites, depending on the arrangement of qubits in the quantum
computer. We remark that our results may also be easily generalized to higher
SU(N) gauge theories.Comment: 15 pages, 4 figures, 3 table
A non-Gaussian landscape
Primordial perturbations with wavelengths greater than the observable universe shift the effective background fields in our observable patch from their global averages over the inflating space. This leads to a landscape picture where the properties of our observable patch depend on its location and may significantly differ from the expectation values predicted by the underlying fundamental inflationary model. We show that if multiple fields are present during inflation, this may happen even if our horizon exit would be preceded by only a few e-foldings of inflation. Non-Gaussian statistics are especially affected: for example models of local non-Gaussianity predicting |f_NL|>> 10 over the entire inflating volume can have a probability up to a few tens of percent to generate a non-detectable bispectrum in our observable patch |fNL^{obs.}|<10. In this work we establish systematic connections between the observable local properties of primordial perturbations and the global properties of the inflating space which reflect the underlying high energy physics. We study in detail the implications of both a detection and non-detection of primordial non-Gaussianity by Planck, and discover novel ways of characterising the naturalness of different observational configurations
Scale dependence of in N-flation
Adopting the horizon-crossing approximation, we derive the spectral index of
in general N-flation model. Axion N-flation model is taken as a
typical model for generating a large which characterizes the size of
local form bispectrum. We find that its tilt is negligibly small
when all inflatons have the same potential, but a negative detectable
can be achieved in the axion N-flation with different decay
constants for different inflatons. The measurement of can be used
to support or falsify the axion N-flation in the near future.Comment: 15 pages, 2 figures; a subsection with detectable scale dependence of
f_NL added; more discussions added and version accepted for publication in
JCA
Futures Reasearch: A New Approach to Long-Range Corporate Planning
This study is an attempt to illustrate the potential use of futures research in long-range corporate planning. The basic purpose of futures research is to involve the corporate concern with an active role in creating future conditions. Outcomes and even the seemingly inevitable can be changed
The paper will study the development of futures research, discuss various techniques and approaches, apply these to the corporation and discuss problems of forecasting. The paper will show that futures research concentrates on the development and application of systematic processes and procedures which are intended to unveil alternatives available to companies over the long-run
The main objective of futures research is to improve the decision making process in the case of long-range planning. More and more decisions are moving from the short-range to the long-range. This is due mainly because our decisions involve increasingly more complex situations. Also, we live i n an age where technological change is almost overwhelming •. _· These considerations have given futures research the prominence we observe toda
Gravity and non-gravity mediated couplings in multiple-field inflation
Mechanisms for the generation of primordial non-Gaussian metric fluctuations
in the context of multiple-field inflation are reviewed. As long as kinetic
terms remain canonical, it appears that nonlinear couplings inducing
non-gaussianities can be split into two types. The extension of the one-field
results to multiple degrees of freedom leads to gravity mediated couplings that
are ubiquitous but generally modest. Multiple-field inflation offers however
the possibility of generating non-gravity mediated coupling in isocurvature
directions that can eventually induce large non-Gaussianities in the metric
fluctuations. The robustness of the predictions of such models is eventually
examined in view of a case study derived from a high-energy physics
construction.Comment: 14 pages, 3 figures, invited review for CQG issue on non-linear
cosmolog
A comparison study of atmospheric radiometric calibration methods for aerial thermograms
A comparison study was conducted to evaluate limitations of several atmospheric calibration techniques, including: Angular, Profile, and spectrally corrected and uncorrected LOWTRAN. To accomplish this, a thermal mapper was flown over a shoreline where water surface temperatures were measured coincidentally by a ground crew. The thermogram derived observed radiances were corrected using each of the atmospheric calibration methods so that ground surface temperatures could be predicted. The R.M.S. errors of these ground temperature predictions indicated that all calibration techniques yielded similar results at 1000-foot altitude. The error remained constant for the Profile and LOWTRAN calibration techniques to 6000-foot altitude, but the Angular results singularly indicated a pronounced altitude dependence in ground temperature prediction errors to 6000-foot altitude
A guide to the identification and importance of custodian farmers
We often talk about custodian farmers; several countries recognized them by facilitating awards and we often interact with them about what they do on their farm? However, some questions remain, “what do we really mean by custodian farmers?", “what are the characteristics of such custodian farmers?”, "what role they for on-farm and in situ conservation projects and beyond?", “what potential roles they can play?” This guide aims to help practitioners to identify and document such farmers in a systematic manner for better understanding and to enable targeted support towards custodian farmers?
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