11,994 research outputs found
SPS fiber optic link assessment
Fiber optic technology was tentatively selected in the SPS baseline design to transmit a stable phase reference throughout microwave array. Over a hundred thousand microwave modules are electronically steered by the phase reference signal to form the power beam at the ground receiving station. The initially selected IF distribution frequency of the phase reference signal was at 980 MHz or a submultiple of it. Fiber optics offers some significant advantages in view of the SPS application. Optical transmission is highly immune to EMI/RFI, which is expected to be severe when considering the low distribution power. In addition, there are savings in both mass, physical size, and potentially in cost
Gestational diabetes mellitus- right person, right treatment, right time?
Background: Personalised treatment that is uniquely tailored to an individual’s phenotype has become a key goal of clinical and pharmaceutical development across many, particularly chronic, diseases. For type 2 diabetes, the importance of the underlying clinical heterogeneity of the condition is emphasised and a range of treatments are now available, with personalised approaches being developed. While a close connection between risk factors for type 2 diabetes and gestational diabetes has long been acknowledged, stratification of screening, treatment and obstetric intervention remains in its infancy.
Conclusions: Although there have been major advances in our understanding of glucose tolerance in pregnancy and of the benefits of treatment of gestational diabetes, we argue that far more vigorous approaches are needed to enable development of companion diagnostics, and to ensure the efficacious and safe use of novel therapeutic agents and strategies to improve outcomes in this common condition
A homomorphism theorem and a Trotter product formula for quantum stochastic flows with unbounded coefficients
We give a new method for proving the homomorphic property of a quantum
stochastic ow satisfying a quantum stochastic differential equation with
unbounded coefficients, under some further hypotheses. As an application, we
prove a Trotter product formula for quantum stochastic ows and obtain quantum
stochastic dilations of a class of quantum dynamical semigroups generalizing
results of [5
The Devil is in the Detail: Hints for Practical Optimisation
Finding the minimum of an objective function, such as a least squares or negative log-likelihood function, with respect to the unknown model parameters is a problem often encountered in econometrics. Consequently, students of econometrics and applied econometricians are usually well-grounded in the broad differences between the numerical procedures employed to solve these problems. Often, however, relatively little time is given to understanding the practical subtleties of implementing these schemes when faced with illbehaved problems. This paper addresses some of the details involved in practical optimisation, such as dealing with constraints on the parameters, specifying starting values, termination criteria and analytical gradients, and illustrates some of the general ideas with several instructive examples.gradient algorithms, unconstrained optimisation, generalised method of moments.
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Legal ideology, legal doctrine and the UK's top judges
Most work on the UK's judiciary reflects the assumption that the institutional issues raised by attitudinal studies of the US Supreme Court are irrelevant to the UK because the UK's judiciary is not political. This article challenges those assumptions. We present an empirical and theoretical analysis of the 'doctrinal model' of judicial decision-making in the upper judiciary of the UK, that is to say, of the position that judges decide cases on the basis of doctrinal positions rather than political views, and argue that it has far more in common with the attitudinal model than is conventionally assumed. We elaborate upon this through an empirical analysis of decisions of the Law Lords on challenges to state bodies over a twenty-five year period, which estimates judges' ideological positions on a scale derived from doctrine. We find that (a) there are meaningful and measurable differences in judicial positions in key doctrinal controversies (b) these differences have an impact on the outcome of a significant minority of cases. Our results support the view that doctrinal positions are more salient than party-political ideology in the UK context, but also demonstrate that even faithful adherence to a doctrinal model does not affect the validity of the insights of the attitudinal model in relation to the role and impact of judges' personal views. We show that on a proper understanding, doctrinal adjudication raises the same questions of institutional structure and design emphasised by the attitudinal model, and that these questions assume particular significance given changes to the British judiciary's institutional role
Modeling eating pathology: The role of gender, sociocultural, and individual factors
Eating pathology is an increasing problem in the United States and other Western countries. This study examined gender differences and specific known psychological correlates of eating pathology. Sociocultural variables, such as thin-ideal internalization, and individual factors, such as perfectionism and experiential avoidance, were also evaluated. A sample of 257 female and 165 male undergraduates (n = 423) completed a battery of surveys online. Structural equation modeling (SEM) was used to model the relationships among the variables. The results show that the best fitting model included perfectionism rather than thin-ideal internalization leading to body dissatisfaction. There is support for experiential avoidance as a mediating variable between body dissatisfaction, dieting, and thin-idealization and binge eating. Results also show that men engaged in more binge eating and exercise than women and less vomiting and laxative use than women. These findings suggest that individual factors, specifically perfectionism and experiential avoidance, are strongly related to eating pathology, particularly binge eating
Experimental Evaluation of Non-Composite Shallow Press-Brake-Formed Steel Tub Girders
The Short Span Steel Bridge Alliance (SSSBA) is a group of bridge industry leaders (including steel manufacturers, fabricators, service centers, coaters, researchers, and representatives of related associations and government organizations) who have joined together to provide educational information on the design and construction of short-span steel bridges in installations up to 140 feet in length (Michaelson, 2014). From within the SSSBA technical working group, a shallow press-brake-formed steel tub girder was developed. This new technology consists of cold-bending standard mill plate width and thicknesses to form a trapezoidal box girder. By eliminating the need to cut and weld plates together, the system proves to be an economical and rapid construction option. The steel plate can either be weathering steel or galvanized steel, each an economical option.;The originally-proposed system consisted of a reinforced concrete deck cast on the girder in the fabrication shop, forming a composite modular unit once cured. The composite unit would then be shipped to the construction site to be installed. However, the option of implementing a cast-in-place deck must be explored. A critical design stage for these girders occurs during pouring of the concrete deck, when the non-composite steel section must support the construction load, including the wet concrete. During this period, the top flanges are in compression and the system is susceptible to torsional buckling and deflection phenomena. Therefore, for a cast-in-place deck option, the non-composite stability and behavior of tub girders needs to be further evaluated.;The scope of this project was to develop a complete understanding of the stability and behavior of non-composite press-brake-formed tub girders for short span bridge applications. This was performed in four stages. A complete literature review focusing on previous studies relating to non-composite trapezoidal steel tub girder behavior was conducted. Destructive flexural testing was then performed on two non-composite specimens to assess the ultimate capacity of the system. Next, nonlinear finite element models were developed and benchmarked against experimental data. Results of the experimental and FEA modeling are used to determine bracing requirements for the non-composite press-brake-formed tub girders to improve their torsional response
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