Search Process Checklist

The Search Process Checklist is a tool that is used in instructional sessions with nurses in reference to evidence-based practice and literature searching. It is intended as a reference handout. It is under a creative commons license. If you would like a version that can be rebranded for your organization to use, please contact the author for an editable version

Information Theory and Knowledge-Gathering

It is assumed that human knowledge-building depends on a discrete sequential decision-making process subjected to a stochastic information transmitting environment. This environment randomly transmits Shannon type information-packets to the decision-maker, who examines each of them for relevancy and then determines his optimal choices. Using this set of relevant information-packets, the decision-maker adapts, over time, to the stochastic nature of his environment, and optimizes the subjective expected rate-of-growth of knowledge. The decision-maker’s optimal actions, lead to a decision function that involves his view of the subjective entropy of the environmental process and other important parameters at each stage of the process. Using this model of human behavior, one could create psychometric experiments using computer simulation and real decision-makers, to play programmed games to measure the resulting human performance.decision-making; dynamic programming; entropy; epistemology; information theory; knowledge; sequential processes; subjective probability

THE WATER RESOURCE PROBLEM

Resource /Energy Economics and Policy,

Coherence methods in mapping AVO anomalies and predicting P-wave and S-wave impedances

Filters for migrated offset substacks are designed by partial coherence analysis to predict ‘normal’ amplitude variation with offset (AVO) in an anomaly free area. The same prediction filters generate localized prediction errors when applied in an AVO-anomalous interval. These prediction errors are quantitatively related to the AVO gradient anomalies in a background that is related to the minimum AVO anomaly detectable from the data. The prediction-error section is thus used to define a reliability threshold for the identification of AVO anomalies. Coherence analysis also enables quality control of AVO analysis and inversion. For example, predictions that are non-localized and/or do not show structural conformity may indicate spatial variations in amplitude–offset scaling, seismic wavelet or signal-to-noise (S/N) ratio content. Scaling and waveform variations can be identified from inspection of the prediction filters and their frequency responses. S/N ratios can be estimated via multiple coherence analysis. AVO inversion of seismic data is unstable if not constrained. However, the use of a constraint on the estimated parameters has the undesirable effect of introducing biases into the inverted results: an additional bias-correction step is then needed to retrieve unbiased results. An alternative form of AVO inversion that avoids additional corrections is proposed. This inversion is also fast as it inverts only AVO anomalies. A spectral coherence matching technique is employed to transform a zero-offset extrapolation or near-offset substack into P-wave impedance. The same technique is applied to the prediction-error section obtained by means of partial coherence, in order to estimate S-wave velocity to P-wave velocity (VS/VP) ratios. Both techniques assume that accurate well ties, reliable density measurements and P-wave and S-wave velocity logs are available, and that impedance contrasts are not too strong. A full Zoeppritz inversion is required when impedance contrasts that are too high are encountered. An added assumption is made for the inversion to the VS/VP ratio, i.e. the Gassmann fluid-substitution theory is valid within the reservoir area. One synthetic example and one real North Sea in-line survey illustrate the application of the two coherence methods

Lower bounds of characteristic scale of topological modification of the Newtonian gravitation

We analytically work out the long-term orbital perturbations induced by the first term of the expansion of the perturbing potential arising from the local modification of the Newton's inverse square law due to a topology R^2 x S^1 with a compactified dimension of radius R recently proposed by Floratos and Leontaris. We neither restrict to any specific spatial direction for the asymmetry axis nor to particular orbital configurations of the test particle. Thus, our results are quite general. Non-vanishing long-term variations occur for all the usual osculating Keplerian orbital elements, apart from the semimajor axis which is left unaffected. By using recent improvements in the determination of the orbital motion of Saturn from Cassini data, we preliminarily inferred R >= 4-6 kau. As a complementary approach, the putative topological effects should be explicitly modeled and solved-for with a modified version of the ephemerides dynamical models with which the same data sets should be reprocessed.Comment: Latex, 6 pages, no tables, 1 figure, 3 references. Accepted for publication in International Journal of Modern Physics D (IJMPD

Correlated few-photon transport in one-dimensional waveguides: linear and nonlinear dispersions

We address correlated few-photon transport in one-dimensional waveguides coupled to a two-level system (TLS), such as an atom or a quantum dot. We derive exactly the single-photon and two-photon current (transmission) for linear and nonlinear (tight-binding sinusoidal) energy-momentum dispersion relations of photons in the waveguides and compare the results for the different dispersions. A large enhancement of the two-photon current for the sinusoidal dispersion has been seen at a certain transition energy of the TLS away from the single-photon resonances.Comment: 6 pages, 5 figures, revised version, to appear in Phys. Rev.

Density Operators for Fermions

The mathematical methods that have been used to analyze the statistical properties of boson fields, and in particular the coherence of photons in quantum optics, have their counterparts for Fermi fields. The coherent states, the displacement operators, the P-representation, and the other operator expansions all possess surprisingly close fermionic analogues. These methods for describing the statistical properties of fermions are based upon a practical calculus of anti-commuting variables. They are used to calculate correlation functions and counting distributions for general systems of fermions.Comment: 45 pages, late