			Home About us Contact

Generating Processes (generating + process)

Distribution by Scientific Domains

Business, Economics, Finance and Accounting	42%

Selected Abstracts

The Stability of the Relation Between the Stock Market and Macroeconomic Forces

ECONOMIC NOTES, Issue 3 2002
Fabio Panetta
This paper identifies the macroeconomic factors that influence Italian equity returns and tests the stability of their relation with securities returns. The relation between stock returns and the macroeconomic factors is found to be unstable: not only are the factor loadings of individual securities virtually uncorrelated over time, but a high percentage of the shares experience a reversal of the sign of the estimated loadings. This result is not confined to single periods or to a small group of shares, but holds in different sub,periods and for securities in all risk classes. These findings suggest that research should carefully investigate the specification of the return generating process and the stability of the risk measures. (J.E.L.: G12, E44). [source]

Monetary Policy, Price Stability and Output Gap Stabilization

INTERNATIONAL FINANCE, Issue 2 2002
Vitor Gaspar
Using a standard New,Keynesian model, this paper examines three reasons why monetary policy should primarily focus on price stability rather than the stabilization of output around potential, even if there appears to be an exploitable trade,off between the volatility of inflation and that of the output gap. First, we discuss the well,known time,inconsistency problem associated with active output gap stabilization. Increasing the relative weight on inflation stabilization improves the equilibrium outcome. Second, we analyse some of the problems associated with the substantial uncertainty that surrounds estimates of potential output. We argue that focusing on price stability is a robust monetary policy strategy in the face of such uncertainty. Finally, we consider the case where private agents are trying to estimate the inflation generating process using an ,ad hoc', but reasonable learning rule. By emphasizing a single goal the central bank facilitates the process of learning, thereby stablizing both inflation and the output gap. [source]

Hierarchical Bayesian Analysis of Correlated Zero-inflated Count Data

BIOMETRICAL JOURNAL, Issue 6 2004
Getachew A. Dagne
Abstract This article presents two-component hierarchical Bayesian models which incorporate both overdispersion and excess zeros. The components may be resultants of some intervention (treatment) that changes the rare event generating process. The models are also expanded to take into account any heterogeneity that may exist in the data. Details of the model fitting, checking and selecting alternative models from a Bayesian perspective are also presented. The proposed methods are applied to count data on the assessment of an efficacy of pesticides in controlling the reproduction of whitefly. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Detection of trends in hydrological extremes for Canadian watersheds

HYDROLOGICAL PROCESSES, Issue 13 2010
Donald H. Burn
Abstract The potential impacts of climate change can alter the risk to critical infrastructure resulting from changes to the frequency and magnitude of extreme events. As well, the natural environment is affected by the hydrologic regime, and changes in high flows or low flows can have negative impacts on ecosystems. This article examines the detection of trends in extreme hydrological events, both high and low flow events, for streamflow gauging stations in Canada. The trend analysis involves the application of the Mann,Kendall non-parametric test. A bootstrap resampling process has been used to determine the field significance of the trend results. A total of 68 gauging stations having a nominal record length of at least 50 years are analysed for two analysis periods of 50 and 40 years. The database of Canadian rivers investigated represents a diversity of hydrological conditions encompassing different extreme flow generating processes and reflects a national scale analysis of trends. The results reveal more trends than would be expected to occur by chance for most of the measures of extreme flow characteristics. Annual and spring maximum flows show decreasing trends in flow magnitude and decreasing trends in event timing (earlier events). Low flow magnitudes exhibit both decreasing and increasing trends. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Assimilation and contrast in optical illusions1

JAPANESE PSYCHOLOGICAL RESEARCH, Issue 1 2007
TAKUO GOTO
Abstract: This study has focused on how assimilation and contrast correlate with the generating processes of various optical illusions. First of all, we defined the meanings of assimilation and contrast from two viewpoints, namely, phenomena and mechanisms. We then examined the characteristic appearances of the Delboeuf illusion as a typical size illusion caused by assimilation and contrast, by referring to major studies on this illusion in Japan. To confirm the different size-judgment processes operating in size illusions of concentric circles, quadrilaterals, lines, and angles, we explored the magnitude of illusion, including peak and conversion from overestimation to underestimation. The consistent occurrences of peak and conversion indicated the antagonistic correlations of assimilation and contrast in the generation of these illusions. Manipulation of figural unification using solid and non-solid segments had no effect on these illusions, which were constructed almost by their own specific contour-patterns. Finally, we tried to incorporate assimilation and contrast into our proposition that the combination of three factors (angle/direction, space/position, and assimilation/contrast) explains the generation of many optical illusions. [source]

On the influence of imaging conditions and algorithms on the quantification of surface topography

JOURNAL OF MICROSCOPY, Issue 3 2002
U. Wendt
Summary The influence of the microscopical magnification resulting in different voxel size and shape and of the algorithm on parameters used for the quantification of the surface topography is studied using topographical images obtained by confocal laser scanning microscopy. Fracture surfaces and wire-eroded surfaces of steel were used as samples. The values obtained for the global topometry parameters normalized surface area, mean profile segment length and fractal dimension depend with different degrees on the microscopic magnification and on the algorithm used to compute these values. The topometry values can only be used to establish correlations between the topography and materials properties and for the modelling of surface generating processes if the imaging and computing details are given. [source]

OPTIMAL AND ADAPTIVE SEMI-PARAMETRIC NARROWBAND AND BROADBAND AND MAXIMUM LIKELIHOOD ESTIMATION OF THE LONG-MEMORY PARAMETER FOR REAL EXCHANGE RATES,

THE MANCHESTER SCHOOL, Issue 2 2005
SAEED HERAVI
The nature of the time series properties of real exchange rates remains a contentious issue primarily because of the implications for purchasing power parity. In particular are real exchange rates best characterized as stationary and non-persistent; nonstationary but non-persistent; or nonstationary and persistent? Most assessments of this issue use the I(0)/I(1) paradigm, which only allows the first and last of these options. In contrast, in the I(d) paradigm, d fractional, all three are possible, with the crucial parameter d determining the long-run properties of the process. This study includes estimation of d by three methods of semi-parametric estimation in the frequency domain, using both local and global (Fourier) frequency estimation, and maximum likelihood estimation of ARFIMA models in the time domain. We give a transparent assessment of the key selection parameters in each method, particularly estimation of the truncation parameters for the semi-parametric methods. Two other important developments are also included. We implement Tanaka's locally best invariant parametric tests based on maximum likelihood estimation of the long-memory parameter and include a recent extension of the Dickey,Fuller approach, referred to as fractional Dickey,Fuller (FD-F), to fractionally integrated series, which allows a much wider range of generating processes under the alternative hypothesis. With this more general approach, we find very little evidence of stationarity for 10 real exchange rates for developed countries and some very limited evidence of nonstationarity but non-persistence, and none of the FD-F tests leads to rejection of the null of a unit root. [source]