introduction echo-planar imaging (epi) is a group of fast data acquisition methods commonly used in fmri studies. it acquires multiple image lines in k-space after a single excitation, which leads to a very short scan time. a well-known problem with epi is that it is more sensitive to distortions due to the used encoding scheme. source of distortion is inhomogeneity in the static b0 field that ...

In cooperative multiagent systems an alternative that maximizes the social welfare—the sum of utilities—can only be selected if each agent reports its full utility function. This may be infeasible in environments where communication is restricted. Employing a voting rule to choose an alternative greatly reduces the communication burden, but leads to a possible gap between the social welfare of ...

Devising methods to publish social network data in a form that affords utility without compromising privacy remains a longstanding challenge, while many existing methods based on k-anonymity algorithms on social networks may result in nontrivial utility loss without analyzing the social network topological structure and without considering the attributes of sparse distribution. Toward this obje...

Work on implicit utilitarian voting advocates the design of voting rules that maximize utilitarian social welfare with respect to latent utility functions, based only on observed rankings of the alternatives. This approach has been successfully deployed in order to help people choose a single alternative or a subset of alternatives, but it has previously been unclear how to apply the same appro...

by analyzing the zero-field-splitting parameters and of cr2+ (3d4) ion located at tetrahedral site in znse crystal, the local structure distortion and absorption spectra around cr2+ in znse: cr2+ system have been calculated on the basis of the complete energy matrix for the d4 configuration within the strong-filed-representation. it is shown that there exists an expansion distortion in the loca...

In this paper we are interested in inference based on heteroskedasticity consistent covariance matrix estimators, for which the appropriate bootstrap is a version of the wild bootstrap. Simulation results, obtained by a new very eÆcient method, show that all wild bootstrap tests exhibit substantial size distortion if the error terms are skewed and strongly heteroskedastic. The distortion is how...

Depression is a common mental disorder. Appropriate support from others can reduce the cognitive distortion that can be caused by subsequent depressions. To increase our understanding of this process, an agent model is presented in this paper in which the positive and negative effects of social support and its relation with cognitive thoughts are modelled. Simulations show the effect of social ...

A neglected effect of monopoly is the distortion in the quantity of resources supplied. Monopoly not only affects the economy's output mix, it also results in factor prices that are below social marginal value products. This latter distortion is shown to be quantitatively important when other policies, such as taxes on labor earnings, also depress factor prices. Under plausible conditions, the ...