17,988 research outputs found
A Geometric Characterisation of the Compromise Value
In this paper, we characterise the compromise value of a game as the barycentre of the edges of its core cover.For this, we introduce the value, which extends the adjusted proportional rule for bankruptcy situations and coincides with the compromise value on a large class of games.geometry;games;bankruptcy;core
A Geometric Characterisation of the Compromise Value
In this paper, we characterise the compromise value of a game as the barycentre of the edges of its core cover.For this, we introduce the value, which extends the adjusted proportional rule for bankruptcy situations and coincides with the compromise value on a large class of games.
Calibration, validation and the NERC Airborne Remote Sensing Facility
The application of airborne and satellite remote sensing to terrestrial applications has been dominated by empirically-based, semi-quantitative approaches, in contrast to those developed in the marine and atmospheric sciences which have often developed from rigorous physically-based models. Furthermore, the traceability of EO data and the methodological basis of many applications has often been taken for granted, with the result that the repeatability of analyses and the reliability of many terrestrial EO products can be questioned. ‘NCAVEO’ is a recently established network of Earth Observation experts and data users committed to exchanging knowledge and understanding in the area of remote sensing data calibration and validation. It aims to provide a UK-based forum to collate available knowledge and expertise associated with the calibration and validation of EO-based products from both UK and overseas providers, in different discipline areas including land, ocean and atmosphere. This paper will introduce NCAVEO and highlight some of the contributions it hopes to make to airborne remote sensing in the UK
From Geometry to Numerics: interdisciplinary aspects in mathematical and numerical relativity
This article reviews some aspects in the current relationship between
mathematical and numerical General Relativity. Focus is placed on the
description of isolated systems, with a particular emphasis on recent
developments in the study of black holes. Ideas concerning asymptotic flatness,
the initial value problem, the constraint equations, evolution formalisms,
geometric inequalities and quasi-local black hole horizons are discussed on the
light of the interaction between numerical and mathematical relativists.Comment: Topical review commissioned by Classical and Quantum Gravity.
Discussion inspired by the workshop "From Geometry to Numerics" (Paris, 20-24
November, 2006), part of the "General Relativity Trimester" at the Institut
Henri Poincare (Fall 2006). Comments and references added. Typos corrected.
Submitted to Classical and Quantum Gravit
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Cavitation Inside Enlarged And Real-Size Fully Transparent Injector Nozzles And Its Effect On Near Nozzle Spray Formation
The effect of string cavitation in various transparent Diesel injector nozzles on near nozzle spray dispersion angle is examined. Additional PDA measurements on spray characteristics produced from real-size transparent nozzle tips are presented. Highspeed imaging has provided qualitative information on the existence of geometric and string cavitation, simultaneously with the temporal variation of the spray angle. Additional use of commercial and in-house developed CFD models has provided complimentary information on the local flow field. Results show that there is strong connection between string cavitation structures and spray instabilities. Moreover, elimination of string cavitation results in a stable spray shape that is only controlled by the extent of geometric-induced cavitation pockets. Finally, PDA measurements on real-size transparent nozzle tips have confirmed that such nozzles reproduce successfully the sprays generated by production metal nozzles
Indoor wireless communications and applications
Chapter 3 addresses challenges in radio link and system design in indoor scenarios. Given the fact that most human activities take place in indoor environments, the need for supporting ubiquitous indoor data connectivity and location/tracking service becomes even more important than in the previous decades. Specific technical challenges addressed in this section are(i), modelling complex indoor radio channels for effective antenna deployment, (ii), potential of millimeter-wave (mm-wave) radios for supporting higher data rates, and (iii), feasible indoor localisation and tracking techniques, which are summarised in three dedicated sections of this chapter
Laserwire at the Accelerator Test Facility 2 with Sub-Micrometre Resolution
A laserwire transverse electron beam size measurement system has been
developed and operated at the Accelerator Test Facility 2 (ATF2) at KEK.
Special electron beam optics were developed to create an approximately 1 x 100
{\mu}m (vertical x horizontal) electron beam at the laserwire location, which
was profiled using a 150 mJ, 71 ps laser pulse with a wavelength of 532 nm. The
precise characterisation of the laser propagation allows the non-Gaussian
transverse profiles of the electron beam caused by the laser divergence to be
deconvolved. A minimum vertical electron beam size of 1.07 0.06 (stat.)
0.05 (sys.) {\mu}m was measured. A vertically focussing quadrupole just
before the laserwire was varied whilst making laserwire measurements and the
projected vertical emittance was measured to be 82.56 3.04 pm rad.Comment: 17 pages, 26 figures, submitted to Phys. Rev. ST Accel. Beam
Geometrically-controlled polarisation processing in an integrated photonic platform
The polarisation of light is a powerful and widely used degree of freedom to
encode information, both in classical and quantum applications. In particular,
quantum information technologies based on photons are being revolutionised by
the use of integrated photonic circuits. It is therefore very important to be
able to manipulate the polarisation of photons in such circuits. We
experimentally demonstrate the fabrication by femtosecond laser micromachining
of components such as polarisation insensitive or polarising directional
couplers, operating at 1550 nm wavelength, where the two opposite behaviours
are achieved just by controlling the geometric layout of the photonic circuits,
being the waveguides fabricated with the same irradiation recipe. We expect to
employ this approach in complex integrated photonic devices, capable of a full
control of the photons polarisation for quantum cryptography, quantum
computation and quantum teleportation experiments.Comment: 9 pages, 7 figure
Integration techniques of pHEMTs and planar Gunn diodes on GaAs substrates
This work presents two different approaches for the implementation of pseudomorphic high electron mobility transistors (pHEMTs) and planar Gunn diodes on the same gallium arsenide substrate. In the first approach, a combined wafer is used where a buffer layer separates the active layers of the two devices. A second approach was also examined using a single wafer where the AlGaAs/InGaAs/GaAs heterostructures were designed for the realisation of pHEMTs. The comparison between the two techniques showed that the devices fabricated on the single pHEMT wafer presented superior performance over the combined wafer technique. The DC and small-signal characteristics of the pHEMTs on the single wafer were enhanced after the use of T-gates with 70 nm length. The maximum transconductance of the transistors was equal to 780 mS/mm with 200 GHz maximum frequency of oscillation (fmax). Planar Gunn diodes fabricated in the pHEMT wafer, with 1.3 μm anode-to-cathode separation (LAC) presented oscillations at 87.6 GHz with maximum power of oscillation equal to -40 dBm
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