3,527 research outputs found
The Core, Periphery, and Beyond: Stock Market Comovements among EU and Non-EU Countries
We thank conference participants at the 2016 Financial Management Association and our discussant Fernando Moreira, and two anonymous referees for immensely helpful comments. We also thank Andrew Patton and James P. LeSage for sharing their MATLAB codes for computing quantile dependence. The authors of this paper are responsible for any errors or omissions. The Securities and Exchange Commission, as a matter of policy, disclaims responsibility for any private publication or statement by any of its employees. The views expressed herein are those of the authors and do not necessarily reflect the views of the Commission or the authors\u27 colleagues on the staff of the Commission
Recommended from our members
Validation of the Implementation Climate Scale (ICS) in substance use disorder treatment organizations.
BackgroundOne critical factor in the implementation of evidence-based practice (EBP) in substance use disorder treatment organizations is an inner organizational context that clearly supports implementation efforts. The Implementation Climate Scale (ICS) has been developed to allow researchers and organizations to assess climate for EBP implementation in health and allied health service organizations. The ICS consists of 18 items and measures six dimensions of implementation climate: focus on EBP, educational support for EBP, recognition for EBP, rewards for EBP, selection for EBP, and selection for openness. The ICS was initially developed in a mental health context; thus, the goal of this study was to provide initial validation of the ICS in substance use disorder (SUD) treatment settings.MethodsConfirmatory factor analysis (CFA) was used to assess the psychometric functioning of the ICS using survey data from 326 providers in 65 teams in SUD treatment programs. Cronbach's alpha was examined to assess internal consistency of the ICS, and individual and team level construct-based validity was examined by comparing its correlations with service climate, molar climate, and organizational change.ResultsWe found evidence for the reliability, factor structure, and validity of the ICS in SUD services. The psychometric functioning of the ICS in SUD treatment settings was comparable to that found in mental health contexts.ConclusionsThe ICS is a brief and pragmatic tool for researchers to better understand a critical antecedent for implementation effectiveness in SUD treatment and for organizational leaders in SUD treatment organizations to evaluate the extent to which providers perceive that their organization supports EBP implementation
Precise Estimation of Cosmological Parameters Using a More Accurate Likelihood Function
The estimation of cosmological parameters from a given data set requires a
construction of a likelihood function which, in general, has a complicated
functional form. We adopt a Gaussian copula and constructed a copula likelihood
function for the convergence power spectrum from a weak lensing survey. We show
that the parameter estimation based on the Gaussian likelihood erroneously
introduces a systematic shift in the confidence region, in particular for a
parameter of the dark energy equation of state w. Thus, the copula likelihood
should be used in future cosmological observations.Comment: 5 pages, 3 figures. Maches version published by the Physical Review
Letter
Block synchronization for quantum information
Locating the boundaries of consecutive blocks of quantum information is a
fundamental building block for advanced quantum computation and quantum
communication systems. We develop a coding theoretic method for properly
locating boundaries of quantum information without relying on external
synchronization when block synchronization is lost. The method also protects
qubits from decoherence in a manner similar to conventional quantum
error-correcting codes, seamlessly achieving synchronization recovery and error
correction. A family of quantum codes that are simultaneously synchronizable
and error-correcting is given through this approach.Comment: 7 pages, no figures, final accepted version for publication in
Physical Review
Financial contagion in real economy: The key role of policy uncertainty
© 2020 John Wiley & Sons Ltd This paper studies the spread of the Subprime Crisis and the European Sovereign Debt Crisis from Eurozone countries to the real economy by examining 10 sectors in major developed and emerging stock markets. First, we employ Cappiello et al., Journal of Financial Economics, 2006, 4, 537–572 model and copula functions to detect and cross-check the correlations and the contagion thereafter. Second, we uncover evidence of correlation behaviour between policy uncertainty indexes and stock market returns. The results demonstrate that no country and sector was immune to spillover effects, highlighting the limited effectiveness of policy makers for both the Subprime Crisis and the European Sovereign Debt Crisis. The empirical application provides evidence of significant volatility and tail dependence from the financial sector to many real sectors in the U.S. economy. Additionally, there is clear evidence that certain sectors, particularly Healthcare, Telecommunications, Utilities and Technology, were less severely affected by the crisis, as observed by Baur, Journal of Banking & Finance, 2011, 36, 2680–2692
Testing fluvial erosion models using the transient response of bedrock rivers to tectonic forcing in the Apennines, Italy
The transient response of bedrock rivers to a drop in base level can be used to
discriminate between competing fluvial erosion models. However, some recent studies of
bedrock erosion conclude that transient river long profiles can be approximately
characterized by a transport‐limited erosion model, while other authors suggest that a
detachment‐limited model best explains their field data. The difference is thought to be
due to the relative volume of sediment being fluxed through the fluvial system. Using a
pragmatic approach, we address this debate by testing the ability of end‐member fluvial
erosion models to reproduce the well‐documented evolution of three catchments in the
central Apennines (Italy) which have been perturbed to various extents by an
independently constrained increase in relative uplift rate. The transport‐limited model is
unable to account for the catchments’response to the increase in uplift rate, consistent with
the observed low rates of sediment supply to the channels. Instead, a detachment‐limited
model with a threshold corresponding to the field‐derived median grain size of the
sediment plus a slope‐dependent channel width satisfactorily reproduces the overall
convex long profiles along the studied rivers. Importantly, we find that the prefactor in the
hydraulic scaling relationship is uplift dependent, leading to landscapes responding faster
the higher the uplift rate, consistent with field observations. We conclude that a slope‐
dependent channel width and an entrainment/erosion threshold are necessary ingredients
when modeling landscape evolution or mapping the distribution of fluvial erosion rates in
areas where the rate of sediment supply to channels is low
Strong Approximation of Empirical Copula Processes by Gaussian Processes
We provide the strong approximation of empirical copula processes by a
Gaussian process. In addition we establish a strong approximation of the
smoothed empirical copula processes and a law of iterated logarithm
Generation of correlated Rayleigh fading channels for accurate simulationof promising wireless communication systems
In this paper, a generalized method is proposed for the accurate simulation of equal/ unequal power correlated Rayleigh fading channels to overcome the shortcomings of existing methods. Spatial and spectral correlations are also considered in this technique for different transmission conditions. It employs successive coloring for the inphase and quadrature components of successive signals using real correlation vector of successive signal envelopes rather than complex covariance matrix of the Gaussian signals which is utilized in conventional methods. Any number of fading signals with any desired correlations
of successive envelope pairs in the interval [0, 1] can be generated with high accuracy. Moreover, factorization of the desired covariance matrix is avoided to overcome the shortcomings and high computational complexity of conventional methods. Extensive simulations of different representative scenarios demonstrate the effectiveness of the proposedtechnique. The simplicity and accuracy of this method will help the researchers to study and simulate the impact of fading correlation on the performance evaluation of various multi-antenna and multicarrier communication systems. Moreover, it enables the engineers for efficient design and deployment of new schemes for feasible wireless
application
- …