16,509 research outputs found

    Likelihood-based statistical estimation from quantized data

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    Most standard statistical methods treat numerical data as if they were real (infinitenumber- of-decimal-places) observations. The issue of quantization or digital resolution is recognized by engineers and metrologists, but is largely ignored by statisticians and can render standard statistical methods inappropriate and misleading. This article discusses some of the difficulties of interpretation and corresponding difficulties of inference arising in even very simple measurement contexts, once the presence of quantization is admitted. It then argues (using the simple case of confidence interval estimation based on a quantized random sample from a normal distribution as a vehicle) for the use of statistical methods based on rounded data likelihood functions as an effective way of dealing with the issue. --

    The Interpretation-Construction Distinction in Patent Law

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    The ambiguity of claim language is generally considered to be the most important problem in patent law today. Linguistic ambiguity is believed to cause tremendous uncertainty about patent rights. Scholars and judges have accordingly devoted enormous attention to developing better linguistic tools to help courts understand patent claims. In this article, we explain why this diagnosis is fundamentally wrong. Claims are not often ambiguous, and linguistic ambiguity is not a major cause of the uncertainty in patent law today. We shall explain what really causes the uncertainty in patent rights, how the erroneous diagnosis of linguistic ambiguity has led the literature off-track, and what will get us back on track to solving the uncertainty problem

    On the Plutinos and Twotinos of the Kuiper Belt

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    We illuminate dynamical properties of Kuiper Belt Objects (KBOs) in the 3:2 (``Plutino'') and 2:1 (``Twotino'') Neptunian resonances within the model of resonant capture and migration. We analyze a series of numerical integrations, each involving the 4 migratory giant planets and 400 test particles distributed throughout trans-Neptunian space, to measure efficiencies of capture as functions of migration speed. Snapshots of the spatial distribution of resonant KBOs reveal that Twotinos cluster +/- 75 degrees away from Neptune's longitude, while Plutinos cluster +/- 90 degrees away. Longitudinal clustering persists even for surveys that are not volume-limited in their ability to detect resonant KBOs. Remarkably, between -90 degrees and -60 degrees of Neptune's longitude, we find the sky density of Twotinos to nearly equal that of Plutinos, despite the greater average distance of Twotinos. We couple our findings to observations to crudely estimate that the intrinsic Twotino population is within a factor of 3 of the Plutino population. Most strikingly, the migration model predicts that more Twotinos may lie at longitudes behind that of Neptune than ahead of it. The magnitude of the asymmetry amplifies dramatically with faster rates of migration and can be as large as 300%. A differential measurement of the sky density of 2:1 resonant objects behind of and in front of Neptune's longitude would powerfully constrain the migration history of that planet.Comment: AJ, in press, to appear in December 2002 issue. For version with higher resolution figures, see http://astron.berkeley.edu/~echiang/ppp/ppp.htm

    Remarks on Form Factor Bounds

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    Improved model independent upper bounds on the weak transition form factors are derived using inclusive sum rules. Comparison of the new bounds with the old ones is made for the form factors h_{A_1} and h_V in B -> D* decays.Comment: 8 pages, 2 figures, title changed and typos corrected for journal publicatio

    The Formation of Ice Giants in a Packed Oligarchy: Instability and Aftermath

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    As many as 5 ice giants--Neptune-mass planets composed of 90% ice and rock and 10% hydrogen--are thought to form at heliocentric distances of 10-25 AU on closely packed orbits spaced ~5 Hill radii apart. Such oligarchies are ultimately unstable. Once the parent disk of planetesimals is sufficiently depleted, oligarchs perturb one another onto crossing orbits. We explore both the onset and the outcome of the instability through numerical integrations, including dynamical friction cooling of planets by a planetesimal disk whose properties are held fixed. To trigger instability and the ejection of the first ice giant in systems having an original surface density in oligarchs of Sigma ~ 1 g/cm^2, the disk surface density s must fall below 0.1 g/cm^2. Ejections are predominantly by Jupiter and occur within 10 Myr. To eject more than 1 oligarch requires s < 0.03 g/cm^2. Systems starting with up to 4 oligarchs in addition to Jupiter and Saturn can readily yield solar-system-like outcomes in which 2 surviving ice giants lie inside 30 AU and have their orbits circularized by dynamical friction. Our numerical simulations support the idea that planetary systems begin in more crowded and compact configurations, like those of shear-dominated oligarchies. In contrast to previous studies, we identify s < 0.1 Sigma as the regime relevant for understanding the evolution of the outer solar system, and we encourage future studies to concentrate on this regime while relaxing our assumption of a fixed planetesimal disk.Comment: Accepted to ApJ Jan 27. Incorporates comments from the referee and community at large. 15 pages, 14 figures, including 7 colo

    Chromo-polarizability and pipi final state interaction

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    The chromo-polarizability of a quarkonium state is a measure of the amplitude of the E1E1-E1E1 chromo-electric interaction of the quarkonium with soft gluon fields and can be measured in the heavy quarkonium decays. Based on the chiral unitary approach, formulas with modification caused by the SS wave ππ\pi\pi final state interaction (FSI) for measuring the chromo-polarizabilities are given. It is shown that the effect of the SS wave ππ\pi\pi FSI is very important in extracting chromo-polarizabilities from the experimental data. The resultant values with the FSI are reduced to about 1/3 of those determined without the FSI. The consequences of the FSI correction in the J/ψJ/\psi-nucleon scattering near the threshold are also discussed. The estimated lower bound of the total cross section is reduced from about 17 mb to 2.9 mb, which agrees with the experimental data point and is compatible with the previously estimated values in the literature. In order to understand the interaction of heavy quarkonia with light hadrons at low energies better and to obtain the chromo-polarizabilities of quarkonia accurately, more data should be accumulated. This can be done in the J/ψπ+πl+lJ/\psi \to \pi^+\pi^-l^+l^- decay at BES-III and CLEO-c and in the Υπ+πl+l\Upsilon \to \pi^+\pi^-l^+l^- decay at B factories.Comment: 5 pages, 3 figures, ReVTeX4. Version accepted for publication in Phys. Rev.

    Dynamic Resonance Effects in the Statistical Distributions of Asteroids and Comets

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    Some principles in the distribution of Centaurs and the "Scattered Disk" objects, as well as the Kuiper belt objects for its semi-major axes, eccentricities and inclinations of the orbits have been investigated. It has been established, that more than a half from them move on the resonant orbits and that is what has been predicted earlier. The divergence of the maximum in the observable distribution of the objects of the Kuiper belt for the semi-major axes with an exact orbital resonance has been interpreted.Comment: 7 pages, 5 figures, 1 table. International Conference "100 years since Tunguska phenomenon: Past, present and future", (June 26-28, 2008. Russia, Moscow), International Conference "Modern problems of astronomy" (August 12-18, 2007, Ukraine, Odessa
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