Prologue: One of the major challenges facing U.S. health system reformers is finding a way to repair the shortcomings of the system while maintaining the cherished American values of autonomy, pluralism, and choice. For this reason, many believe that looking to health systems such as Canadas or Great Britain's—which reflect the centralized nature of their respective governments—as models for reform has only limited usefulness. Our population is vast and diverse; we value individual over collective endeavor; and we prefer local problem solving to federal mandates. Any health system reforms that are to succeed must accommodate these unique aspects of American culture and politics. In this paper, Stephen Shortell proposes an approach to health system reform built on these assumptions. His model, called health promotion and accountability regions (HPARs), are, in his words, “common incentive structures for managing population-based care. “The HPARs, organized as public/private partnerships at the state level, “serve as an organizational cornerstone around which health care reform might be implemented,” he explains. The model includes both basic benefit packages and financing options, linking the functions of planning, insurance, payment, delivery, and evaluation. Shortell is the A.C. Buehler Distinguished Professor of Health Services Management and professor of organization behavior in the Department of Organization Behavior of Northwestern University's J.L. Kellogg Graduate School of Management in Evanston, Illinois, where he is also a member of the Center for Health Services and Policy Research. He holds a doctoral degree in the behavioral sciences from the University of Chicago. Shortell is senior author of the award-winning book Strategic Choices for America's Hospitals: Managing Change in Turbulent Times and is a member of the National Academy of Sciences' Institute of Medicine.
Bulk amorphous alloys, such as the Zr41.2Ti13.8Cu12.5Ni10Be22.5 (at.%) alloy, have received much interest lately, particularly for their commercial application in golf club heads. This study seeks to investigate the fatigue behavior of this Zr-based amorphous metal in the presence of air and sodium chloride solution, with the specific goal of identifying mechanisms of environmentally assisted fatigue-crack growth in these environments. Results from experiments, including fatigue testing in air and sodium chloride, fatigue under potential control, and static load testing in sodium chloride, suggest that quite distinct mechanisms of fatigue-crack propagation are active in air and sodium chloride solution. Specifically, the fatigue-crack growth rates observed under static and cyclic loading in sodium chloride likely depend on an anodic process, which results in a brittle mode of failure. Conversely in air, fatigue-crack propagation is associated with alternating blunting and re-sharpening of the crack tip, as evidenced by the presence of classic fatigue striations.
Convolutional image classifiers can achieve high predictive accuracy, but quantifying their uncertainty remains an unresolved challenge, hindering their deployment in consequential settings. Existing uncertainty quantification techniques, such as Platt scaling, attempt to calibrate the network's probability estimates, but they do not have formal guarantees. We present an algorithm that modifies any classifier to output a predictive set containing the true label with a user-specified probability, such as 90%. The algorithm is simple and fast like Platt scaling, but provides a formal finite-sample coverage guarantee for every model and dataset. Our method modifies an existing conformal prediction algorithm to give more stable predictive sets by regularizing the small scores of unlikely classes after Platt scaling. In experiments on both Imagenet and Imagenet-V2 with ResNet-152 and other classifiers, our scheme outperforms existing approaches, achieving coverage with sets that are often factors of 5 to 10 smaller than a stand-alone Platt scaling baseline.
This paper gives a new sufficient condition for complete stability of a nonsymmetric cellular neural network (CNN). The convergence theorem of the Gauss-Seidel method, which is an iterative technique for solving a linear algebraic equation, plays an important role in our proof. It is also shown that the existence of a stable equilibrium point does not imply complete stability of a nonsymmetric CNN.
Optical spectra of the Type II supernova 1987F, obtained shortly after discovery and at late times, are atypical of SNe II. When first observed, broad Hα was superposed on a nearly featureless continuum, but its profile did not have the characteristic P Cygni shape, and its centroid was blueshifted by >~1500 km s^-1^ with respect to the systemic velocity. Many months later, the object was dominated by broad permitted emission lines of hydrogen, with Fe II and Ca II emission detected as well; forbidden lines, normally quite strong at this phase, were very weak. The derived electron density in the ejected envelope at this time was >~10^9^ cm^-3^. Together with the observed expansion velocities, this leads to an estimate of M>~5-30 M_sun_ for the envelope, implying that the progenitor was very massive. The light curve, which declined very slowly at both early and late times, supports this conclusion. With a few small but possibly significant exceptions, the overall optical spectroscopic properties of SN 1987F closely resemble those of Type I Seyfert nuclei and QSOs; in particular, a comparison is made with the spectrum of 3C 48. The same can be said for the much less extensively observed Type II SN 1988I, although in this object there is no direct evidence for Fe II emission. Even the optical luminosities of the SNe are comparable to those of moderately active galactic nuclei. Had either of these SNe occurred in the nucleus of a normal galaxy, the nucleus would probably have been classified as a Type I Seyfert the only data available were low-resolution optical spectra. It is possible that certain environment conditions, such as the presence of a dense interstellar medium, may increase the rate at which object such as SN 1987F and SN 1988I are produced. Following the work of Terlevich and Melnick, I suggest that the observed properties of some low-luminosity active galaxies might actually be due to violent bursts of star formation rather than accretion onto a supermassive black hole.
We review the debate on the association of financial globalization with inequality. We show that the within-country distributional impact of capital account liberalization is context specific and that different types of flows have different distributional effects. Their overall impact depends on the composition of capital flows, their interaction, and on broader economic and institutional conditions. A comprehensive set of policies – macroeconomic, financial and labor- and product-market specific – is important for facilitating wider sharing of the benefits of financial globalization.
Given the need to provide users with reasonable feedback about the "costs" their network usage incurs, and the increasingly commercial nature of the Internet, we believe that the allocation of cost among users will play an important role in future networks. This paper discusses cost allocation in the context of multicast flows. The question we discuss is this: when a single data flow is shared among many receivers, how does one split the cost of that flow among the receivers? Multicast routing increases network efficiency by using a single shared delivery tree. We address the issue of how these savings are allocated among the various members of the multicast group. We first consider an axiomatic approach to the problem, analyzing the implications of different distributive notions on the resulting allocations. We then consider a one-pass mechanism to implement such allocation schemes and investigate the family of allocation schemes such mechanisms can support.
