Panic behavior and the performance of circuit breakers: Empirical evidence

Stock Markets;Financial Crisis

Non-monotonicity of the frictional bimaterial effect

Sliding along frictional interfaces separating dissimilar elastic materials is qualitatively different from sliding along interfaces separating identical materials due to the existence of an elastodynamic coupling between interfacial slip and normal stress perturbations in the former case. This bimaterial coupling has important implications for the dynamics of frictional interfaces, including their stability and rupture propagation along them. We show that while this bimaterial coupling is a monotonically increasing function of the bimaterial contrast, when it is coupled to interfacial shear stress perturbations through a friction law, various physical quantities exhibit a non-monotonic dependence on the bimaterial contrast. In particular, we show that for a regularized Coulomb friction, the maximal growth rate of unstable interfacial perturbations of homogeneous sliding is a non-monotonic function of the bimaterial contrast, and provide analytic insight into the origin of this non-monotonicity. We further show that for velocity-strengthening rate-and-state friction, the maximal growth rate of unstable interfacial perturbations of homogeneous sliding is also a non-monotonic function of the bimaterial contrast. Results from simulations of dynamic rupture along a bimaterial interface with slip-weakening friction provide evidence that the theoretically predicted non-monotonicity persists in non-steady, transient frictional dynamics.Comment: 14 pages, 5 figure

AGGREGATE DEMAND AND TECHNOLOGICAL CHANGES: A MACRO-ECONOMIC MODEL OF INDUCED INNOVATIONS

Research and Development/Tech Change/Emerging Technologies,

Applying the Unmotivated Label to Clients in Social Service Agencies

This study, based on the responses of a sample of 245 public-sector social workers, explores the factors associated with labelling clients unmotivated. The variables examined relate to clients, workers, agencies, and the interactions among these elements. Multiple regression analysis reveals that the best predictor variables are client-related. The client most likely to be rated by the social worker as lacking in motivation is of lower socioeconomic status and is perceived as believing that he or she does not require much professional intervention. The research supports the argument that clients who workers believe are unreceptive to their professional styles are likely to be labelled unmotivated

Tax Neutralization in Employment Cases Comes to California: Clemens and Economy

This paper is designed to explain the concept of tax neutralization as it applies to non-physical injury legal cases and to describe the two legal cases that brought acceptance of this concept to all California courts

The Willingness to Seek Help: Its Role in Social Workers\u27 Professional Commitment

Providing help to persons in need is the central theme of the social work profession. The three elements essential to this process are the person offering the assistance, the assistance itself, and the person receiving it. The focus here is on the person offering the help and to what degree that person is willing to request help when he or she needs it. Social workers differ with regard to their willingness to seek help, and this study employs a variety of research tools to explore the relevance of these differences to their commitment to the profession and to their professional advancement. The research, carried out in Israel with a sample of 180 professional social workers, found greater willingness to seek help to be directly associated with greater professional commitment and indirectly associated with enhanced upward career mobility