18,115 research outputs found
Adult Learning Theory: Insights Relevant to the Appropriation of Ideas, Theories, Concepts and Models by Management Practitioners.
The core aim of the overall research project is to explore the appropriation of ideas, theories, concepts and models by individual management practitioners
Are North-South Technological Spillovers Substantial? : A Dynamic Panel Data Model Estimation
This paper argues that actual technological spillovers are not substantial in developing countries because of the absence of an absorptive capacity. We carry out a panel data analysis in an attempt to gain insight into the specific aspects that enable economies to benefit from the backlog of existing knowledge. Our findings indicate that low productivity effects of human capital coupled with weak or virtually inexistent systems of innovation are at the root of the observed ambiguity with regard to the spillovers gains that are expected to play a significant role in sparking growth.absorptive capacity, spillovers, developing countries, systems of innovation
Weak gravitational lensing: reducing the contamination by intrinsic alignments
Intrinsic alignments of galaxies can mimic to an extent the effects of shear
caused by weak gravitational lensing. Previous studies have shown that for
shallow surveys with median redshifts z_m = 0.1, the intrinsic alignment
dominates the lensing signal. For deep surveys with z_m = 1, intrinsic
alignments are believed to be a significant contaminant of the lensing signal,
preventing high-precision measurements of the matter power spectrum. In this
paper we show how distance information, either spectroscopic or photometric
redshifts, can be used to down-weight nearby pairs in an optimised way, to
reduce the errors in the shear signal arising from intrinsic alignments.
Provided a conservatively large intrinsic alignment is assumed, the optimised
weights will essentially remove all traces of contamination. For the Sloan
spectroscopic galaxy sample, residual shot noise continues to render it
unsuitable for weak lensing studies. However, a dramatic improvement for the
slightly deeper Sloan photometric survey is found, whereby the intrinsic
contribution, at angular scales greater than 1 arcminute, is reduced from about
80 times the lensing signal to a 10% effect. For deeper surveys such as the
COMBO-17 survey with z_m = 0.6, the optimisation reduces the error from a
largely systematic 220% error at small angular scales to a much smaller and
largely statistical error of only 17% of the expected lensing signal. We
therefore propose that future weak lensing surveys be accompanied by the
acquisition of photometric redshifts, in order to remove fully the unknown
intrinsic alignment errors from weak lensing detections.Comment: 10 pages, 6 figures, MNRAS accepted. Minor changes to match accepted
version. RCS and ODT predictions are modifie
Explaining Data-Driven Decisions made by AI Systems: The Counterfactual Approach
We examine counterfactual explanations for explaining the decisions made by
model-based AI systems. The counterfactual approach we consider defines an
explanation as a set of the system's data inputs that causally drives the
decision (i.e., changing the inputs in the set changes the decision) and is
irreducible (i.e., changing any subset of the inputs does not change the
decision). We (1) demonstrate how this framework may be used to provide
explanations for decisions made by general, data-driven AI systems that may
incorporate features with arbitrary data types and multiple predictive models,
and (2) propose a heuristic procedure to find the most useful explanations
depending on the context. We then contrast counterfactual explanations with
methods that explain model predictions by weighting features according to their
importance (e.g., SHAP, LIME) and present two fundamental reasons why we should
carefully consider whether importance-weight explanations are well-suited to
explain system decisions. Specifically, we show that (i) features that have a
large importance weight for a model prediction may not affect the corresponding
decision, and (ii) importance weights are insufficient to communicate whether
and how features influence decisions. We demonstrate this with several concise
examples and three detailed case studies that compare the counterfactual
approach with SHAP to illustrate various conditions under which counterfactual
explanations explain data-driven decisions better than importance weights
The WiggleZ Dark Energy Survey: the selection function and z=0.6 galaxy power spectrum
We report one of the most accurate measurements of the three-dimensional
large-scale galaxy power spectrum achieved to date, using 56,159 redshifts of
bright emission-line galaxies at effective redshift z=0.6 from the WiggleZ Dark
Energy Survey at the Anglo-Australian Telescope. We describe in detail how we
construct the survey selection function allowing for the varying target
completeness and redshift completeness. We measure the total power with an
accuracy of approximately 5% in wavenumber bands of dk=0.01 h/Mpc. A model
power spectrum including non-linear corrections, combined with a linear galaxy
bias factor and a simple model for redshift-space distortions, provides a good
fit to our data for scales k < 0.4 h/Mpc. The large-scale shape of the power
spectrum is consistent with the best-fitting matter and baryon densities
determined by observations of the Cosmic Microwave Background radiation. By
splitting the power spectrum measurement as a function of tangential and radial
wavenumbers we delineate the characteristic imprint of peculiar velocities. We
use these to determine the growth rate of structure as a function of redshift
in the range 0.4 < z < 0.8, including a data point at z=0.78 with an accuracy
of 20%. Our growth rate measurements are a close match to the self-consistent
prediction of the LCDM model. The WiggleZ Survey data will allow a wide range
of investigations into the cosmological model, cosmic expansion and growth
history, topology of cosmic structure, and Gaussianity of the initial
conditions. Our calculation of the survey selection function will be released
at a future date via our website wigglez.swin.edu.au.Comment: 21 pages, 22 figures, accepted for publication in MNRA
Customer-engineer relationship management for converged ICT service companies
Thanks to the advent of converged communications services (often referred to as âtriple playâ), the next generation Service Engineer will need radically different skills, processes and tools from todayâs counterpart. Why? in order to meet the challenges of installing and maintaining services based on multi-vendor software and hardware components in an IP-based network environment. The converged services environment is likely to be âsmartâ and support flexible and dynamic interoperability between appliances and computing devices. These radical changes in the working environment will inevitably force managers to rethink the role of Service Engineers in relation to customer relationship management. This paper aims to identify requirements for an information system to support converged communications service engineers with regard to customer-engineer relationship management. Furthermore, an architecture for such a system is proposed and how it meets these requirements is discussed
Information Aggregation with Costly Information and Random Ordering: Experimental Evidence
The cost of information is an often ignored factor in economic situations although the information acquisition behavior of the decision makers has a crucial influence on the outcome. In this experiment, we study an information aggregation process in which participants decide in a random sequence. Participants observe predecessors decisions and can acquire additional private information at a fixed price. We analyze participants information acquisition behavior and updating procedures. About one half of the individuals act rationally, whereas the other participants systematically overestimate the private signal value. This leads to excessive signal acquisitions and reduced conformity.
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