David A. Singer

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With mobile computing and powerful laptops, databases with sensitive data can be physically retrieved by malicious users who can employ techniques that were not previously thought of, such as disk scans, compromising the data by bypassing the database management system software or database user authentication processes. Or, when databases are provided as a(More)
This article argues that the institutional mandates of central banks have an important influence on inflation outcomes in the advanced industrialized countries. Central banks that are also responsible for bank regulation will be more sensitive to the profitability and stability of the banking sector and therefore less likely to alter interest rates solely(More)
The relationship between third-party contract enforcement and informal networks raises important sociological, political, and economic questions. When economic activity is embedded in social structures, what are the implications of third-party contract enforcement for the scope and nature of economic relations? What determines whether individuals rely on(More)
We consider eigenvalue inclusion regions based on the field of values, pseudospectra, Gershgorin region, and Brauer region of the inverse of a shifted matrix. A family of these inclusion regions is derived by varying the shift. We study several properties, one of which is that the intersection of a family is exactly the spectrum. The numerical approximation(More)
The trace Tf of a smooth function f of a real or complex variable is defined and shown to be invariant under conjugation by Möbius transformations. We associate with a convex curve of class C2 in the unit disk with the Poincaré metric a diffeomorphism of the circle and show that the trace of the diffeomorphism is twice the reciprocal of the geodesic(More)
This paper reviews the literature on ambulatory substance abuse treatment for adolescents, including brief intervention, Twelve-Step-based outpatient treatment, family-based treatment, cognitive behavioral therapy, and pharmacologic treatment. An overview of socially and culturally specific strategies is also included. The diversity of settings and(More)
We describe here a deformation theorem for geodesic fields on a Riemannian manifold and an obstruction whose vanishing is necessary and sufficient for deforming one geodesic field into another. As an application we prove that every smooth manifold of dimension > 2 can be given a Riemannian metric with a nontriangulable cut locus. In [5] we obtain an(More)