Interpolation in waveform space: enhancing the accuracy of gravitational waveform families using numerical relativity

Matched-filtering for the identification of compact object mergers in gravitational-wave antenna data involves the comparison of the data stream to a bank of template gravitational waveforms. Typically the template bank is constructed from phenomenological waveform models since these can be evaluated for an arbitrary choice of physical parameters. Recently it has been proposed that singular value decomposition (SVD) can be used to reduce the number of templates required for detection. As we show here, another benefit of SVD is its removal of biases from the phenomenological templates along with a corresponding improvement in their ability to represent waveform signals obtained from numerical relativity (NR) simulations. Using these ideas, we present a method that calibrates a reduced SVD basis of phenomenological waveforms against NR waveforms in order to construct a new waveform approximant with improved accuracy and faithfulness compared to the original phenomenological model. The new waveform family is given numerically through the interpolation of the projection coefficients of NR waveforms expanded onto the reduced basis and provides a generalized scheme for enhancing phenomenological models.Comment: 10 pages, 7 figure

Institutional, financing and pricing principles

Presented during the Third international conference on irrigation and drainage held March 30 - April 2, 2005 in San Diego, California. The theme of the conference was "Water district management and governance."Includes bibliographical references.The International Commission on Irrigation and Drainage created a Committee in 2001 to prepare a Position Paper in response to the World Water Vision's proposed "full pricing" of services to ensure sustainability. International experience in the structuring of service entities, cost recovery and financing investments was considered in the adopted response. Historically, beneficiaries formed what have proved to be self-sufficient service entities for urban supply, irrigation and agricultural and storm drainage. Rapid expansion of services by governments after 1945, resulted in services that were not self-sufficient and systems having serious physical deficiencies in design and construction. Under-funding of O&M due to inadequate cost recovery and insufficient subsidies resulted in mounting obligations. Structuring system transfers to beneficiaries has proven difficult at best.Sponsored by USCID; co-sponsored by Association of California Water Agencies and International Network for Participatory Irrigation Management

The breakdown flash of Silicon Avalance Photodiodes - backdoor for eavesdropper attacks?

Silicon avalanche photodiodes are the most sensitive photodetectors in the visible to near infrared region. However, when they are used for single photon detection in a Geiger mode, they are known to emit light on the controlled breakdown used to detect a photoelectron. This fluorescence light might have serious impacts on experimental applications like quantum cryptography or single-particle spectroscopy. We characterized the fluorescence behaviour of silicon avalanche photodiodes in the experimentally simple passive quenching configuration and discuss implications for their use in quantum cryptography systems.Comment: 9 pages, 6 figures, submitted to J. Mod. Optic

Frictional Duality Observed during Nanoparticle Sliding

One of the most fundamental questions in tribology concerns the area dependence of friction at the nanoscale. Here, experiments are presented where the frictional resistance of nanoparticles is measured by pushing them with the tip of an atomic force microscope. We find two coexisting frictional states: While some particles show finite friction increasing linearly with the interface areas of up to 310,000nm^2, other particles assume a state of frictionless sliding. The results further suggest a link between the degree of surface contamination and the occurrence of this duality.Comment: revised versio