1,139 research outputs found
Pluricomplex Green and Lempert functions for equally weighted poles
For a domain in , the pluricomplex Green function with
poles is defined as .
When there is only one pole, or two poles in the unit ball, it turns out to be
equal to the Lempert function defined from analytic disks into by . It is known
that we always have . In the more general case where we
allow weighted poles, there is a counterexample to equality due to Carlehed and
Wiegerinck, with equal to the bidisk.
Here we exhibit a counterexample using only four distinct equally weighted
poles in the bidisk. In order to do so, we first define a more general notion
of Lempert function "with multiplicities", analogous to the generalized Green
functions of Lelong and Rashkovskii, then we show how in some examples this can
be realized as a limit of regular Lempert functions when the poles tend to each
other. Finally, from an example where in the case of
multiple poles, we deduce that distinct (but close enough) equally weighted
poles will provide an example of the same inequality. Open questions are
pointed out about the limits of Green and Lempert functions when poles tend to
each other.Comment: 25 page
Towards the integration of functions, relations and types in an AI programming language
This paper describes the design and implementation of the programming language PC-Life. This language integrates the functional and the Logic-oriented programming style and feature types supporting inheritance. This combination yields a language particularly suited to knowledge representation, especially for application in computational linguistics
On the selection of AGN neutrino source candidates for a source stacking analysis with neutrino telescopes
The sensitivity of a search for sources of TeV neutrinos can be improved by
grouping potential sources together into generic classes in a procedure that is
known as source stacking. In this paper, we define catalogs of Active Galactic
Nuclei (AGN) and use them to perform a source stacking analysis. The grouping
of AGN into classes is done in two steps: first, AGN classes are defined, then,
sources to be stacked are selected assuming that a potential neutrino flux is
linearly correlated with the photon luminosity in a certain energy band (radio,
IR, optical, keV, GeV, TeV). Lacking any secure detailed knowledge on neutrino
production in AGN, this correlation is motivated by hadronic AGN models, as
briefly reviewed in this paper.
The source stacking search for neutrinos from generic AGN classes is
illustrated using the data collected by the AMANDA-II high energy neutrino
detector during the year 2000. No significant excess for any of the suggested
groups was found.Comment: 43 pages, 12 figures, accepted by Astroparticle Physic
Dynamic flow synthesis of porous organic cages
The dynamic covalent synthesis of two imine-based porous organic cages was successfully transferred from batch to continuous flow. The same flow reactor was then used to scramble the constituents of these two cages in differing ratios to form cage mixtures. Preparative HPLC purification of one of these mixtures allowed rapid access to a desymmetrised cage molecule.We thank the Engineering and Physical Sciences Research Council (EPSRC) for financial support under the Grants EP/H000925/1 (AIC), EP/K009494/1 (SVL) and EP/M004120/1 (SVL), and Pfizer Worldwide Research & Development (CB). The authors would like to thank EPSRC Dial-a-Molecule Grand Challenge Network (EP/K004840/1) for funding a placement with SVL via the Interdisciplinary Mobility Funding scheme (AGS).This is the author accepted manuscript. The final version is available from RSC via http://dx.doi.org/10.1039/C5CC07447
An Evaluation Model For Web-based 3D Mass Customization Toolkit Design
The development of geometric modelling technologies and web technologies provides the ability to present a virtual 3D product in a mass customization (MC) toolkit. Compared with 2D graphic toolkits, 3D toolkit design requires better consideration of individual customer needs, consumer and toolkit interaction, and also a means of integrating with the underlying technical infrastructure. However, there is currently no widely accepted model or criteria to regulate and evaluate 3D MC toolkit design. Given these considerations, in this paper we provide an evaluation model for web-based 3D toolkits and a heuristic evaluation of two representative commercial web-based 3D toolkits. The evaluation results indicate the usefulness and effectiveness of the model as a scale for evaluating 3D toolkits. It also reveals that despite a fair amount of effort that has been devoted to theoretical research, current 3D toolkits are still at an early development stage. We therefore conclude this paper by identifying and encouraging further topics and questions as directions for future research
Unpacking the relationships between impulsivity, neighborhood disadvantage, and adolescent violence : an application of a neighborhood-based group decomposition
The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007–2013)/ERC Grant Agreement no. 615159 (ERC Consolidator Grant DEPRIVEDHOODS, Socio-spatial inequality, deprived neighbourhoods, and neighbourhood effects); and from the Marie Curie programme under the European Union’s Seventh Framework Programme (FP/2007–2013)/Career Integration Grant no. PCIG10-GA-2011-303728 (CIG Grant NBHCHOICE, Neighbourhood choice, neighbourhood sorting, and neighbourhood effects).Scholars have become increasingly interested in how social environments condition the relationships between individual risk-factors and adolescent behavior. An appreciable portion of this literature is concerned with the relationship between impulsivity and delinquency across neighborhood settings. The present article builds upon this growing body of research by considering the more nuanced pathways through which neighborhood disadvantage shapes the development of impulsivity and provides a situational context for impulsive tendencies to manifest in violent and aggressive behaviors. Using a sample of 12,935 adolescent from the National Longitudinal Study of Adolescent to Adult Health (Add Health) (mean age = 15.3, 51% female; 20% Black, 17% Hispanic), we demonstrate the extent to which variation in the association between impulsivity and delinquency across neighborhoods can be attributed to (1) differences in mean-levels of impulsivity and violence and (2) differences in coefficients across neighborhoods. The results of a series of multivariate regression models indicate that impulsivity is positively associated with self-reported violence, and that this relationship is strongest among youth living in disadvantaged neighborhoods. The moderating effect of neighborhood disadvantage can be attributed primarily to the stronger effect of impulsivity on violence in these areas, while differences in average levels of violence and impulsivity account for a smaller, yet nontrivial portion of the observed relationship. These results indicate that the differential effect of impulsivity on violence can be attributed to both developmental processes that lead to the greater concentration of violent and impulsive adolescents in economically deprived neighborhoods as well as the greater likelihood of impulsive adolescents engaging in violence when they reside in economically disadvantaged communities.Publisher PDFPeer reviewe
Structures of the intermediates in the catalytic cycle of mitochondrial cytochrome c oxidase
Cytochrome c oxidase is the terminal complex of the respiratory chains in the mitochondria of nearly all eu-karyotes. It catalyzes the reduction of molecular O-2 to water using electrons from the respiratory chain, delivered via cytochrome c on the external surface of the inner mitochondrial membrane. The protons required for water formation are taken from the matrix side of the membrane, making catalysis vectorial. This vectorial feature is further enhanced by the fact that the redox catalysis is coupled to the translocation of protons from the inside to the outside of the inner mitochondrial membrane. We are dealing with a molecular machine that converts redox free energy into a protonmotive force (pmf). Here, we review the current extensive knowledge of the structural changes in the active heme-copper site that accompany catalysis, based on a large variety of time-resolved spectroscopic experiments, X-ray and cryoEM structures, and advanced computational chemistry.Peer reviewe
Unveiling relationships between crime and property in England and Wales via density scale-adjusted metrics and network tools
Scale-adjusted metrics (SAMs) are a significant achievement of the urban scaling hypothesis. SAMs remove the inherent biases of per capita measures computed in the absence of isometric allometries. However, this approach is limited to urban areas, while a large portion of the world’s population still lives outside cities and rural areas dominate land use worldwide. Here, we extend the concept of SAMs to population density scale-adjusted metrics (DSAMs) to reveal relationships among different types of crime and property metrics. Our approach allows all human environments to be considered, avoids problems in the definition of urban areas, and accounts for the heterogeneity of population distributions within urban regions. By combining DSAMs, cross-correlation, and complex network analysis, we find that crime and property types have intricate and hierarchically organized relationships leading to some striking conclusions. Drugs and burglary had uncorrelated DSAMs and, to the extent property transaction values are indicators of affluence, twelve out of fourteen crime metrics showed no evidence of specifically targeting affluence. Burglary and robbery were the most connected in our network analysis and the modular structures suggest an alternative to "zero-tolerance" policies by unveiling the crime and/or property types most likely to affect each other
International Seminar on Corporate Initiatives in Ergonomics Stockholm 19-20 March 1999
The idea of setting up a special action program for ergonomics is rather new in our country. The National Institute for Working Life had no expertise experience in the field when we started to organize the seminar. It showed that it was quite hard to find any programs at all in Sweden. We only found two of any larger format, at Volvo Car and Saab Automobile. In other countries the situation seems to be about the same. However, some companies have a substantial experience and some of these were invited to the seminar. The aim of the seminar was to bring together interested management, health and safety personnel to discuss the design and experience of ergonomic action programs within companies and organisations. Presentations have been performed by invited representatives from 13 companies with experience of programs from Scandinavia, Western Europe, and the USA. In addition to this, a number of researchers have given review presentations of the general state of the art of ergonomics as well as economic and quality aspects of ergonomic measures. Starting with this seminar we hope to find ways of implementing new ergonomic action programs in companies and organisations.Internationellt seminarium om ergonomiska aktionsprogram för företag, Stockholm 19-20 mars 1999. Idén att sätta upp speciella ergonomiska handlingsprogram är rätt ny i vårt land. Arbetslivsinstitutet hade ingen specialkompetens på området innan vi började förberedelserna med seminariet. Det visade sig att det var svårt att hitta några program överhuvudtaget i Sverige. Vi fann bara två med någon större tyngd, vid Volvo Car Company och Saab Automobile. I andra länder tycks situationen vara densamma. Emellertid, har några företag skaffat sig avsevärd erfarenhet på området och några av dessa bjöds in till seminariet. Syftet med seminariet var att föra samman intresserade personer från management och företagshälsovården för att diskutera designen och erfarenheten av ergonomiska handlingsprogram i företag och organisationer. Presentationer gjordes av inbjudna representanter från 13 företag med erfarenheter av program från Skandinavien, Västeuropa och USA. Dessutom, har ett antal forskare givit presentationer av forskningsläget inom ergonomiområdet, t ex i samband med ekonomi och kvalitet. Med detta seminarium hoppas vi finna sätt att påbörja arbetet med att implementera nya ergonomiska handlingsprogram i företag och organisationer
Detection of Atmospheric Muon Neutrinos with the IceCube 9-String Detector
The IceCube neutrino detector is a cubic kilometer TeV to PeV neutrino
detector under construction at the geographic South Pole. The dominant
population of neutrinos detected in IceCube is due to meson decay in cosmic-ray
air showers. These atmospheric neutrinos are relatively well-understood and
serve as a calibration and verification tool for the new detector. In 2006, the
detector was approximately 10% completed, and we report on data acquired from
the detector in this configuration. We observe an atmospheric neutrino signal
consistent with expectations, demonstrating that the IceCube detector is
capable of identifying neutrino events. In the first 137.4 days of livetime,
234 neutrino candidates were selected with an expectation of 211 +/-
76.1(syst.) +/- 14.5(stat.) events from atmospheric neutrinos
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