13,032 research outputs found
Women's secure hospital services: national bed numbers and distribution.
A mapping exercise as part of a pathway study of women in secure psychiatric services in the England and Wales was conducted. It aimed to (i) establish the extent and range of secure service provision for women nationally and (ii) establish the present and future care needs and pathways of care of women mentally disordered offenders (MDO) currently in low, medium and enhanced medium secure care. The study identified 589 medium secure beds, 46 enhanced medium secure beds (WEMSS) and 990 low secure beds for women nationally. Of the 589 medium secure beds, the majority (309, 52%) are in the NHS and under half (280, 48%) are in the independent sector (IS). The distribution of low secure beds is in the opposite direction, the majority (745, 75%) being in the IS and 254 (25%) in the NHS. Medium secure provision for women has grown over the past decade, but comparative data for low secure provision are not available. Most women are now in single sex facilities although a small number of mixed sex units remain. The findings have implications for the future commissioning of secure services for women
Randomized benchmarking in measurement-based quantum computing
Randomized benchmarking is routinely used as an efficient method for
characterizing the performance of sets of elementary logic gates in small
quantum devices. In the measurement-based model of quantum computation, logic
gates are implemented via single-site measurements on a fixed universal
resource state. Here we adapt the randomized benchmarking protocol for a single
qubit to a linear cluster state computation, which provides partial, yet
efficient characterization of the noise associated with the target gate set.
Applying randomized benchmarking to measurement-based quantum computation
exhibits an interesting interplay between the inherent randomness associated
with logic gates in the measurement-based model and the random gate sequences
used in benchmarking. We consider two different approaches: the first makes use
of the standard single-qubit Clifford group, while the second uses recently
introduced (non-Clifford) measurement-based 2-designs, which harness inherent
randomness to implement gate sequences.Comment: 10 pages, 4 figures, comments welcome; v2 published versio
Complexity of pattern classes and Lipschitz property
Rademacher and Gaussian complexities are successfully used in learning theory for measuring the capacity of the class of functions to be learned. One of the most important properties for these complexities is their Lipschitz property: a composition of a class of functions with a fixed Lipschitz function may increase its complexity by at most twice the Lipschitz constant. The proof of this property is non-trivial (in contrast to the other properties) and it is believed that the proof in the Gaussian case is conceptually more difficult then the one for the Rademacher case. In this paper we give a detailed prove of the Lipschitz property for the Rademacher case and generalize the same idea to an arbitrary complexity (including the Gaussian). We also discuss a related topic about the Rademacher complexity of a class consisting of all the Lipschitz functions with a given Lipschitz constant. We show that the complexity is surprisingly low in the one-dimensional case. The question for higher dimensions remains open
Approximating electronically excited states with equation-of-motion linear coupled-cluster theory
A new perturbative approach to canonical equation-of-motion coupled-cluster
theory is presented using coupled-cluster perturbation theory. A second-order
M{\o}ller-Plesset partitioning of the Hamiltonian is used to obtain the well
known equation-of-motion many-body perturbation theory (EOM-MBPT(2)) equations
and two new equation-of-motion methods based on the linear coupled-cluster
doubles (EOM-LCCD) and linear coupled-cluster singles and doubles (EOM-LCCSD)
wavefunctions. This is achieved by performing a short-circuiting procedure on
the MBPT(2) similarity transformed Hamiltonian. These new methods are
benchmarked against very accurate theoretical and experimental spectra from 25
small organic molecules. It is found that the proposed methods have excellent
agreement with canonical EOM-CCSD state for state orderings and relative
excited state energies as well as acceptable quantitative agreement for
absolute excitation energies compared with the best estimate theory and
experimental spectra.Comment: 9 pages 3 figure
An evaluation of a constrained test method for obtaining free body responses
A method for obtaining free body responses from dynamic tests on a constrained structure is investigated for practical feasibility. The method is based on the principle that a constrained structure can be considered to be a free body acted upon by multiple forces which include the forces of constraint. By measuring these forces and by exciting the structure so as to develop linearly independent sets of forces, the response of the free body to one force at a time can be computed. Techniques for producing these independent forces are discussed. The development of the theory, computer simulations of tests of representative aerospace vehicles (including experimental error), and a description and listing of the computer programs developed are included. The procedure appears to be a practical method for obtaining in-flight characteristics of such vehicles
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