2,617 research outputs found

    Quantization of Solitons in Coset Space

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    The perturbation theory around the soliton fields of the sin-Gordon model is developed in the coset space. It is shown by explicit calculations that all corrections to the topological soliton contribution are canceled exactly.Comment: 28 pages, Latex, no figure

    Predictions of ultra-harmonic oscillations in coupled arrays of limit cycle oscillators

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    Coupled distinct arrays of nonlinear oscillators have been shown to have a regime of high frequency, or ultra-harmonic, oscillations that are at multiples of the natural frequency of individual oscillators. The coupled array architectures generate an in-phase high-frequency state by coupling with an array in an anti-phase state. The underlying mechanism for the creation and stability of the ultra-harmonic oscillations is analyzed. A class of inter-array coupling is shown to create a stable, in-phase oscillation having frequency that increases linearly with the number of oscillators, but with an amplitude that stays fairly constant. The analysis of the theory is illustrated by numerical simulation of coupled arrays of Stuart-Landau limit cycle oscillators.Comment: 24 pages, 9 figures, accepted to Phys. Rev. E, in pres

    The Paradoxes of Defensive Medicine

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    For decades, “defensive medicine” has been the leading argument driving reforms of medical malpractice laws throughout the United States. Defensive medicine is the presumed practice of administering excessive tests and treatments as a stratagem for reducing healthcare providers’ risk of malpractice liability, despite the absence of any expected benefit for the patient. The practice is widely believed to exist throughout American healthcare as a response to fears of malpractice litigation, and thought to be enormously wasteful of healthcare dollars. In consequence, it has become a justification for law reforms insulating the healthcare industry from tort liability. These claims are promoted by the healthcare industry even though they imply that most providers routinely engage in healthcare fraud and violate their own ethical rules. We review the evidence behind these beliefs—including direct physician surveys, clinical scenario studies, and multivariate analyses of actual case data—and find little support and numerous paradoxes. The validity vel non of the defensive medicine narrative has implications for law and legal policy, as well as healthcare economics and patient safety

    The Psychology of Trial Judging

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    Trial court judges play a crucial role in the administration of justice for both criminal and civil matters. Although psychologists have studied juries for many decades, they have paid relatively little attention to judges. Recent writings, however, suggest that there is increasing interest in the psychology of judicial decision making. In this article, I review several selected areas of judicial behavior in which decisions appear to be influenced by psychological dispositions, but I caution that a mature psychology of judging field will need to consider the influence of the bureaucratic court setting in which judges are embedded, judges’ legal training, and the constraints of legal precedent

    Complete chaotic synchronization in mutually coupled time-delay systems

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    Complete chaotic synchronization of end lasers has been observed in a line of mutually coupled, time-delayed system of three lasers, with no direct communication between the end lasers. The present paper uses ideas from generalized synchronization to explain the complete synchronization in the presence of long coupling delays, applied to a model of mutually coupled semiconductor lasers in a line. These ideas significantly simplify the analysis by casting the stability in terms of the local dynamics of each laser. The variational equations near the synchronization manifold are analyzed, and used to derive the synchronization condition that is a function of the parameters. The results explain and predict the dependence of synchronization on various parameters, such as time-delays, strength of coupling and dissipation. The ideas can be applied to understand complete synchronization in other chaotic systems with coupling delays and no direct communication between synchronized sub-systems.Comment: 22 pages, 6 figure

    Developing a Framework for Child Welfare Supervision

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    The roles of the child welfare supervisor in guiding practice and in retaining child welfare workers are well established in the literature. In this article, we discuss a framework for child welfare supervision that was developed and implemented in the state of Iowa with support from the Children’s Bureau through a five-year grant to improve recruitment and retention in public child welfare. The framework supports family centered practice through a parallel process of supervision reflecting these guiding principles: strength-based, competency-based, culturally competent, reflective, individualized to workers’ learning styles and stages of development, and aimed at enhancing worker skill, autonomy, teamwork, and commitment to the organization. We present key elements of the framework, an overview of implementation, and evaluation results regarding knowledge gain, use of skills, and rates of worker retention
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