62 research outputs found

    Observation of Nonspreading Wave Packets in an Imaginary Potential

    Get PDF
    We propose and experimentally demonstrate a method to prepare a nonspreading atomic wave packet. Our technique relies on a spatially modulated absorption constantly chiseling away from an initially broad de Broglie wave. The resulting contraction is balanced by dispersion due to Heisenberg's uncertainty principle. This quantum evolution results in the formation of a nonspreading wave packet of Gaussian form with a spatially quadratic phase. Experimentally, we confirm these predictions by observing the evolution of the momentum distribution. Moreover, by employing interferometric techniques, we measure the predicted quadratic phase across the wave packet. Nonspreading wave packets of this kind also exist in two space dimensions and we can control their amplitude and phase using optical elements.Comment: 4 figure

    Ownership and control in a competitive industry

    Get PDF
    We study a differentiated product market in which an investor initially owns a controlling stake in one of two competing firms and may acquire a non-controlling or a controlling stake in a competitor, either directly using her own assets, or indirectly via the controlled firm. While industry profits are maximized within a symmetric two product monopoly, the investor attains this only in exceptional cases. Instead, she sometimes acquires a noncontrolling stake. Or she invests asymmetrically rather than pursuing a full takeover if she acquires a controlling one. Generally, she invests indirectly if she only wants to affect the product market outcome, and directly if acquiring shares is profitable per se. --differentiated products,separation of ownership and control,private benefits of control

    Beyond ‘geo-economics’: advanced unevenness and the anatomy of German austerity

    Get PDF
    This article aims to shed new light on Germany’s domineering role in the eurocrisis. I argue that the realist-inspired depiction of Germany as a ‘geo-economic power’, locked into zero-sum competition with its European partners, is built around an empty core: unable to theorise how anarchy shapes the calculus of states where security competition has receded, it cannot explain why German state managers have insisted on an austerity response to the crisis despite its significant risks and costs even for Germany itself. To unlock this puzzle, this article outlines a version of uneven and combined development (UCD) that is better able to capture the international pressures and opportunities faced by policy elites in advanced capitalist states that no longer encounter one another as direct security rivals. Applied to Germany, this lens reveals a twofold unevenness in the historical structures and growth cycles of capitalist economies that shape its contradictory choice for austerity. In the long run, the reorientation of the export-dependent German economy from Europe towards Asian and Latin American late industrialisers renders the structural adjustment of the eurozone an opportunity—from the cost-saving view of German manufacturers producing in the European home market for export abroad, as well as for German state officials keen to sustain a crumbling class compromise centred on Germany’s world market success. In the short term, however, its exposed position between the divergent post-crisis trajectories of the US and Europe accelerates pressures for austerity beyond what German state and corporate elites would otherwise consider feasible

    Naive Bayes ant colony optimization for designing high dimensional experiments

    Get PDF
    In a large number of experimental problems, high dimensionality of the search area and economical constraints can severely limit the number of experimental points that can be tested. Within these constraints, classical optimization techniques perform poorly, in particular, when little a priori knowledge is available. In this work we investigate the possibility of combining approaches from statistical modeling and bio-inspired algorithms to effectively explore a huge search space, sampling only a limited number of experimental points. To this purpose, we introduce a novel approach, combining ant colony optimization (ACO) and naive Bayes classifier (NBC) that is, the naive Bayes ant colony optimization (NACO) procedure. We compare NACO with other similar approaches developing a simulation study. We then derive the NACO procedure with the goal to design artificial enzymes with no sequence homology to the extant one. Our final aim is to mimic the natural fold of 200 amino acids 1AGY serine esterase from Fusarium solani

    Research trends in combinatorial optimization

    Get PDF
    Acknowledgments This work has been partially funded by the Spanish Ministry of Science, Innovation, and Universities through the project COGDRIVE (DPI2017-86915-C3-3-R). In this context, we would also like to thank the Karlsruhe Institute of Technology. Open access funding enabled and organized by Projekt DEAL.Peer reviewedPublisher PD

    Gene selection for cancer classification with the help of bees

    Full text link

    Searching for Maximum Cliques with Ant Colony Optimization

    No full text
    In this paper, we investigate the capabilities of Ant Colony Optimization (ACO) for solving the maximum clique problem. We describe Ant-Clique, an algorithm that successively generates maximal cliques through the repeated addition of vertices into partial cliques

    Factors associated with medication information in diabetes care: differences in perceptions between patients and health care professionals

    No full text
    Gerda Längst,1 Hanna Marita Seidling,2,3 Marion Stützle,2,3 Dominik Ose,1 Ines Baudendistel,1 Joachim Szecsenyi,1 Michel Wensing,1,4 Cornelia Mahler1 1Department of General Practice and Health Services Research, University Hospital of Heidelberg, Heidelberg, Germany; 2Cooperation Unit Clinical Pharmacy, University of Heidelberg, Heidelberg, Germany; 3Department of Clinical Pharmacology and Pharmacoepidemiology, University of Heidelberg, Heidelberg, Germany; 4Radboud University Nijmegen Medical Centre, Scientific Institute for Quality of Healthcare, Nijmegen, the Netherlands Purpose: This qualitative study in patients with type 2 diabetes and health care professionals (HCPs) aimed to investigate which factors they perceive to enhance or impede medication information provision in primary care. Similarities and differences in perspectives were explored.Methods: Eight semistructured focus groups were conducted, four with type 2 diabetes patients (n=25) and four with both general practitioners (n=13) and health care assistants (n=10). Sessions were audio and video recorded, transcribed verbatim, and subjected to computer-aided qualitative content analysis.Results: Diabetes patients and HCPs broadly highlighted similar factors as enablers for satisfactory medication information delivery. Perceptions substantially differed regarding impeding factors. Both patients and HCPs perceived it to be essential to deliver tailored information, to have a trustful and continuous patient–provider relationship, to regularly reconcile medications, and to provide tools for medication management. However, substantial differences in perceptions related to impeding factors included the causes of inadequate information, the detail required for risk-related information, and barriers to medication reconciliation. Medication self-management was a prevalent topic among patients, whereas HCPs’ focus was on fulfilling therapy and medication management responsibilities.Conclusion: The findings suggest a noteworthy gap in perceptions between information provision and patients’ needs regarding medication-related communication. Medication safety and adherence may be improved if HCPs collaborate more closely with diabetes patients in managing their medication, in particular by incorporating the patients’ perspective. Health care systems need to be structured in a way that supports this process. Keywords: medication information, patient–provider communication, type 2 diabetes, focus groups, primary car
    • 

    corecore