415 research outputs found
Bounds for codes and designs in complex subspaces
We introduce the concepts of complex Grassmannian codes and designs. Let
G(m,n) denote the set of m-dimensional subspaces of C^n: then a code is a
finite subset of G(m,n) in which few distances occur, while a design is a
finite subset of G(m,n) that polynomially approximates the entire set. Using
Delsarte's linear programming techniques, we find upper bounds for the size of
a code and lower bounds for the size of a design, and we show that association
schemes can occur when the bounds are tight. These results are motivated by the
bounds for real subspaces recently found by Bachoc, Coulangeon and Nebe, and
the bounds generalize those of Delsarte, Goethals and Seidel for codes and
designs on the complex unit sphere.Comment: 33 pages, no figure
Language of Lullabies: The Russification and De-Russification of the Baltic States
This article argues that the laws for promotion of the national languages are a legitimate means for the Baltic states to establish their cultural independence from Russia and the former Soviet Union
Position-dependent mass models and their nonlinear characterization
We consider the specific models of Zhu-Kroemer and BenDaniel-Duke in a
sech-mass background and point out interesting correspondences with the
stationary 1-soliton and 2-soliton solutions of the KdV equation in a
supersymmetric framework.Comment: 8 Pages, Latex version, Two new references are added, To appear in
J.Phys.A (Fast Track Communication
Nanoscale Mineralogy and Composition of Experimental Regolith Agglutinates Produced under Asteroidal Impact Conditions
On the Moon, the energetics of smaller impactors and the physical/chemical characteristics of the granular regolith target combine to form a key product of lunar space weathering: chemically reduced shock melts containing optically-active nanophase Fe metal grains (npFe0) [1]. In addition to forming the optically dark glassy matrix phase in lunar agglutinitic soil particles [1], these shock melts are becoming increasingly recognized for their contribution to optically active patina coatings on a wide range of exposed rock and grain surfaces in the lunar regolith [2]. In applying the lessons of lunar space weathering to asteroids, the potential similarities and differences in regolith-hosted shock melts on the Moon compared to those on asteroids has become a topic of increasing interest [3,4]. In a series of impact experiments performed at velocities applicable to the asteroid belt [5], Horz et al. [6] and See and Horz [7] have previously shown that repeated impacts into a gabbroic regolith analog target can produce melt-welded grain aggregates morphologically very similar to lunar agglutinates [6,7]. Although these agglutinate-like particles were extensively analyzed by electron microprobe and scanning electron microscopy (SEM) as part of the original study [7], a microstructural and compositional comparison of these aggregates to lunar soil agglutinates at sub-micron scales has yet to be made. To close this gap, we characterized a representative set of these aggregates using a JEOL 7600 field-emission scanning electron microscope (FE-SEM), and JEOL 2500SE field-emission scanning transmission electron microscope (FE-STEM) both optimized for energy dispersive X-ray spectroscopy (EDX) compositional spectrum imaging at respective analytical spatial resolutions of 0.5 to 1 micron, and 2 to 4 nm
'Studies will yield clues on varsity gender gap'
KUALA LUMPUR: Many quarters lauded the government's initiative to implement a vocational technical based curriculum for secondary schools but suggested more studies
be conducted to determine the real cause for the gender disparity in universities
Effects of R-parity violating supersymmetry in top pair production at linear colliders with polarized beams
In the minimal supersymmetric standard model with R-parity violation, the
lepton number violating top quark interactions can contribute to the top pair
production at a linear collider via tree-level u-channel squark exchange
diagrams. We calculate such contributions and find that in the allowed range of
these R-violating couplings, the top pair production rate as well as the top
quark polarization and the forward-backward asymmetry can be significantly
altered. By comparing the unpolarized beams with the polarized beams, we find
that the polarized beams are more powerful in probing such new physics.Comment: 10 pages, 6 fig
Reaching everyone in general practice?:Feasibility of an integrated domestic violence training and support intervention in primary care
Background Primary care needs to respond effectively to patients experiencing or perpetrating domestic violence and abuse (DVA) and their children, but there is uncertainty about the value of integrated programmes. The aim of the study was to develop and test the feasibility of an integrated primary care system-level training and support intervention, called IRIS+ (Enhanced Identification and Referral to Improve Safety), for all patients affected by DVA. IRIS+ was an adaptation of the original IRIS (Identification and Referral to Improve Safety) model designed to reach female survivors of DVA. Methods Observation of training; pre/post intervention questionnaires with clinicians and patients; data extracted from medical records and DVA agency; semi-structured interviews with clinicians, service providers and referred adults and children. Data collection took place between May 2017 and April 2018. Mixed method analysis was undertaken to triangulate data from various sources to assess the feasibility and acceptability of the intervention. Results Clinicians and service providers believed that the IRIS+ intervention had filled a service gap and was a valuable resource in identifying and referring women, men and children affected by DVA. Despite increased levels of preparedness reported by clinicians after training in managing the complexity of DVA in their practice, the intervention proved to be insufficient to catalyse identification and specialist referral of men and direct identification and referral (without their non-abusive parents) of children and young people. The study also revealed that reports provided to general practice by other agencies are important sources of information about adult and children patients affected by DVA. However, in the absence of guidance about how to use this information in patient care, there are uncertainties and variation in practice. Conclusions The study demonstrates that the IRIS+ intervention is not feasible in the form and timeframe we evaluated. Further adaptation is required to achieve identification and referral of men and children in primary care: an enhanced focus on engagement with men, direct engagement with children, and improved guidance and training on responding to reports of DVA received from other agencies
‘It felt like there was always someone there for us’:supporting children affected by domestic violence and abuse who are identified by general practice
One in five children in the UK are affected by domestic violence and abuse. However, primary care clinicians (GPs and nurses) struggle to effectively identify and support children and young people living in homes where it is present. The IRIS+ (Enhanced Identification and Referral to Improve Safety) training and advocacy support intervention aimed to improve how clinicians respond to children and young people affected by domestic violence and abuse. IRIS+ training was delivered as part of a feasibility study to four general practices in an urban area in England (UK). Our mixed method design included interviews and questionnaires about the IRIS+ intervention with general practice patients, including children and young people as well as with clinicians and advocacy service providers. We collected the number of identifications and referrals by clinicians of children experiencing domestic violence and abuse through a retrospective search of medical and agency records 10 months after the intervention. Forty-nine children exposed to domestic violence and abuse were recorded in medical records. Thirty-five children were referred to a specialist domestic violence and abuse support service over a period of 10 months. Of these, 22 received direct or indirect support. The qualitative findings indicated that children benefitted from being referred by clinicians to the service. However, several barriers at the patient and professional level prevented children and young people from being identified and supported. Some of these barriers can be addressed through modifications to professional training and guidance, but others require systematic and structural changes to the way health and social care services work with children affected by domestic violence and abuse
Reconstructing World Politics: Norms, Discourse, and Community
This Article argues that the conventional (rationalist) approach to world politics characterized by political bargain cannot fully capture the new social reality under the contemporary global ambience where ideational factors such as ideas, values, culture, and norms have become more salient and influential not only in explaining but also in prescribing state behaviors. After bringing rationalism’s paradigmatic limitations into relief, the Article offers a sociological framework that highlights a reflective, intersubjective communication among states and consequent norm-building process. Under this new paradigm, one can understand an international organization as a “community” (Gemeinschaft), not as a mere contractual instrument of its contracting parties (Gesellschaft). The Article applies the new paradigm to the World Trade Organization (WTO) as it describes the WTO’s institutional evolution from a power-oriented, tariff-reducing contract to a norm-oriented world trade community
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