Principal Component Analysis of Cavity Beam Position Monitor Signals

Model-independent analysis (MIA) methods are generally useful for analysing complex systems in which relationships between the observables are non-trivial and noise is present. Principle Component Analysis (PCA) is one of MIA methods allowing to isolate components in the input data graded to their contribution to the variability of the data. In this publication we show how the PCA can be applied to digitised signals obtained from a cavity beam position monitor (CBPM) system on the example of a 3-cavity test system installed at the Accelerator Test Facility 2 (ATF2) at KEK in Japan. We demonstrate that the PCA based method can be used to extract beam position information, and matches conventional techniques in terms of performance, while requiring considerably less settings and data for calibration

Crossover behavior for complex order parameter in high-Tc superconductors

A number of recent experiments have suggested the presence of either real or complex components in the gap symmetry of high-$T_c$ superconductors (HTSC). In this paper we introduce a novel approach to study the competition of such complex order parameter mixtures by varying the position of the two-body attractive potential in a two dimensional extended Hubbard Hamiltonian. We show that this procedure explain a number of experimental results and on the theoretical side, it may be related with certain HTSC microscopic models like the spin fluctuation theory. Following current trends we concentrate on the study of $d_{x^2-y^2}$ order parameter with a component of the type $d_{xy}$ or a s-wave like $s_{x^2+y^2}$ and $s_{xy}$ symmetry. We show that the position of the optimal s-component peak changes with the position parameter $b$ while the d-component occurs always in the optimally region around hole content $\rho \approx 0.39$.Comment: 6 pages in RevTex, 5 figs. in epsi, accepted in the Physica

Random graphs with clustering

We offer a solution to a long-standing problem in the physics of networks, the creation of a plausible, solvable model of a network that displays clustering or transitivity -- the propensity for two neighbors of a network node also to be neighbors of one another. We show how standard random graph models can be generalized to incorporate clustering and give exact solutions for various properties of the resulting networks, including sizes of network components, size of the giant component if there is one, position of the phase transition at which the giant component forms, and position of the phase transition for percolation on the network.Comment: 5 pages, 2 figure

Profile morphology and polarization of young pulsars

We present polarization profiles at 1.4 and 3.1 GHz for 14 young pulsars with characteristic ages less than 75 kyr. Careful calibration ensures that the absolute position angle of the linearly polarized radiation at the pulsar is obtained. In combination with previously published data we draw three main conclusions about the pulse profiles of young pulsars. (1) Pulse profiles are simple and consist of either one or two prominent components. (2) The linearly polarized fraction is nearly always in excess of 70 per cent. (3) In profiles with two components the trailing component nearly always dominates, only the trailing component shows circular polarization and the position angle swing is generally flat across the leading component and steep across the trailing component. Based on these results we can make the following generalisations about the emission beams of young pulsars. (1) There is a single, relatively wide cone of emission from near the last open field lines. (2) Core emission is absent or rather weak. (3) The height of the emission is between 1 and 10 per cent of the light cylinder radius.Comment: Accepted for publication in MNRAS. 16 page

Higher Order Thought and the Problem of Radical Confabulation

Currently, one of the most influential theories of consciousness is Rosenthal's version of higher-order-thought (HOT). We argue that the HOT theory allows for two distinct interpretations: a one-component and a two-component view. We further argue that the two-component view is more consistent with his effort to promote HOT as an explanatory theory suitable for application to the empirical sciences. Unfortunately, the two-component view seems incapable of handling a group of counterexamples that we refer to as cases of radical confabulation. We begin by introducing the HOT theory and by indicating why we believe it is open to distinct interpretations. We then proceed to show that it is incapable of handling cases of radical confabulation. Finally, in the course of considering various possible responses to our position, we show that adoption of a disjunctive strategy, one that would countenance both one-component and two-component versions, would fail to provide any empirical or explanatory advantage

Paleomagnetism of Upper Vendian sediments from the Winter Coast, White Sea region, Russia: Implications for the paleogeography of Baltica during Neoproterozoic times

Paleomagnetic results from an Upper Vendian sedimentary sequence exposed along the White Sea shoreline, NW Russia are described. These classical exposures have been the subject of intense paleontological investigations due to their well-preserved Ediacara fauna, but no paleomagnetic results have as yet been published. A total of 337 hand samples and 210 oriented drill cores (35 sites) along three profiles have been collected at the locality (65.5°, 40.0°E) where a 555 ± 3 Ma U–Pb age of comagmatic zircons from volcanic ash layers has been recently obtained. Standard paleomagnetic procedures yield two main natural remanent magnetization (NRM) components: an intermediate-temperature (150°–350°C), single-polarity component (D = 121°, I = 72°, n = 232 samples, k = 46.0, α95 = 1.3°, pole position at 40.0°N, 79.0°E, dp = 2.0°, dm = 2.3°) and a high-temperature (550°–680°C) dual-polarity component (normal polarity: D = 278°, I = 43°, n = 54 samples, k = 25.2, α95 = 3.9°, reversed polarity: D = 101°, I = −39° n = 40, K = 23.3, α95 = 4.8°, south pole position at 24°S, 132°E, dp = 2.3°, dm = 3.8°). This latter component, termed Z, passes reversal, stratigraphic, and consistency tests and is interpreted to reflect the direction of the Earth's magnetic field during Late Vendian times. These results put Baltica into low northern latitudes (between 10° and 35°) and the resulting pole position requires modification of the most recent Apparent Polar Wander Paths (APWP) for Baltica

A combinatorial move on the set of Jenkins-Strebel differentials

We describe an elementary combinatorial move on the set of quadratic differentials with a horizontal one cylinder decom-position. Computer experiment suggests that the corresponding equivalent classes are in one-to-one correspondence with the con-nected component of the strata

Lidar remote sensing from space: NASA's plans in the Earth sciences

A multidisciplinary study of the Earth System to provide a better understanding of the complex interrelated processes involved in the system, the Earth Observing System (EOS), is being developed. Capabilities of the Space Station, both the polar orbiting platform and the lower inclination platforms, will be used to accommodate a number of large active and/or passive sensors. Two lidar instruments being considered as part of the Eos payload are the Lidar Atmospheric Sounder and Altimeter (LASA) and the Laser Atmospheric Wind Sounder (LAWS). The LASA instrument is separable into two portions: the atmospheric sounder component and the retroranging component. The LASA atmospheric sounder will sample the spatial distribution of several atmospheric parameters. The retroranging component will be used to determine the precise three-dimensional position of specifically placed retro-reflectors and to sense how these retro-reflectors change position over monthly to yearly time periods. The LAWS utilizes a lidar system capable of measuring the Doppler shift in the backscattered intensity to determine the wind velocity profile

The Process of Generating Single Large Combined Cloud for Grid-Free Solvers

Dealing with moving body problems, where one component moves relatively with respect to other, is a difficult task in CFD due to the efforts needed in grid handling for every delta change in position of the moving component. The inherent nature of mesh-free solvers reduces the efforts needed for these kinds of problems by operating on a cloud of points rather than a grid. A new method to handle moving body problems is proposed, where individual clouds are generated around each component and are combined into a single large combined cloud. The proposed method is applied to store separation problem and results generated using NAL-MCIR mesh-less solver is compared with experimental results