MIMO Frechet filters for hyperspectral images

Медианная фильтрация широко используется при обработке изображений, в которых пиксель представляется набором его скалярных компонент, значение пикселя заменяется медианой пикселей в окне вокруг него. В данной работе рассматриваются изображения, в которых пиксели представляются вектором в цветовом пространстве. Обработка данных изображений основывается на идее о том, что медиана – это значение пикселя, сумма расстояний до которого от остальных пикселей окна минимальна. Медиана Фреше дискретного набора векторнозначных пикселей в пространстве с метрикой является точкой минимума суммы метрических расстояний до всех пикселей. В этой статье расширяется понятие медианы Фреше до обобщенной медианы Фреше, которая является минимумом стоимостной функцией Фреше, представленной агрегационной функцией метрических расстояний, вместо обычной суммы. Кроме того, мы предлагаем использовать агрегационное расстояние вместо классической метрики расстояния. Мы используем обобщенную медиану Фреше для построения новых нелинейных многоканальных фильтров. Качество подавления шума данными фильтрами сравнивается с основными алгоритмами: медианным и усредняющим.Median filtering has been widely used in scalar-valued image processing as an edge preserving operation. The basic idea is that the pixel value is replaced by the median of the pixels contained in a window around it. In this work this idea is extended onto vector-valued images. It is based on the fact that the median is also the value that minimizes the sum of distances between all grey-level pixels in the window. The Frechet median of a discrete set of vector-valued pixels in a metric space with a metric is the point minimizing the sum of metric distances to the all sample pixels. In this paper, we extend the notion of the Frechet median to the general Frechet median, which minimizes the Frechet cost function (FCF) in the form of aggregation function of metric distances, instead of the ordinary sum. Moreover, we propose use an aggregation distance instead of classical metric distance. We use generalized Frechet median for constructing new nonlinear MIMO-filters. Noise reduction quality of the introduced method is evaluated and compared with some classic algorithms like mean and median filtering

Experimental investigation of high-energy photon splitting in atomic fields

The new data analysis of the experiment, where the photon splitting in the atomic fields has been observed for the first time, is presented. This experiment was performed at the tagged photon beam of the ROKK-1M facility at the VEPP-4M collider. In the energy region of 120-450 MeV, the statistics of $1.6\cdot 10^9$ photons incident on the BGO target was collected. About 400 candidates to the photon splitting events were reconstructed. Within the attained experimental accuracy, the experimental results are consistent with the cross section calculated exactly in an atomic field. The predictions obtained in the Born approximation significantly differ from the experimental results.Comment: 11 pages, 6 figures, LaTe

Status of the Super-B factory Design

The SuperB international team continues to optimize the design of an electron-positron collider, which will allow the enhanced study of the origins of flavor physics. The project combines the best features of a linear collider (high single-collision luminosity) and a storage-ring collider (high repetition rate), bringing together all accelerator physics aspects to make a very high luminosity of 10$^{36}$ cm$^{-2}$ sec$^{-1}$. This asymmetric-energy collider with a polarized electron beam will produce hundreds of millions of B-mesons at the $\Upsilon$(4S) resonance. The present design is based on extremely low emittance beams colliding at a large Piwinski angle to allow very low $\beta_y^\star$ without the need for ultra short bunches. Use of crab-waist sextupoles will enhance the luminosity, suppressing dangerous resonances and allowing for a higher beam-beam parameter. The project has flexible beam parameters, improved dynamic aperture, and spin-rotators in the Low Energy Ring for longitudinal polarization of the electron beam at the Interaction Point. Optimized for best colliding-beam performance, the facility may also provide high-brightness photon beams for synchrotron radiation applications

Precise measurement of RudsR_{\text{uds}} and RR between 1.84 and 3.72 GeV at the KEDR detector

The present work continues a series of the KEDR measurements of the $R$ value that started in 2010 at the VEPP-4M $e^+e^-$ collider. By combining new data with our previous results in this energy range we measured the values of $R_{\text{uds}}$ and $R$ at nine center-of-mass energies between 3.08 and 3.72 GeV. The total accuracy is about or better than $2.6\%$ at most of energy points with a systematic uncertainty of about $1.9\%$. Together with the previous precise $R$ measurement at KEDR in the energy range 1.84-3.05 GeV, it constitutes the most detailed high-precision $R$ measurement near the charmonium production threshold.Comment: arXiv admin note: text overlap with arXiv:1610.02827 and substantial text overlap with arXiv:1510.0266

Measurement of J/ψ→γηcJ/\psi\to\gamma\eta_{\rm c} decay rate and ηc\eta_{\rm c} parameters at KEDR

Using the inclusive photon spectrum based on a data sample collected at the $J/\psi$ peak with the KEDR detector at the VEPP-4M $e^+e^-$ collider, we measured the rate of the radiative decay $J/\psi\to\gamma\eta_{\rm c}$ as well as $\eta_{\rm c}$ mass and width. Taking into account an asymmetric photon lineshape we obtained $\Gamma^0_{\gamma\eta_{\rm c}}=2.98\pm0.18 \phantom{|}^{+0.15}_{-0.33}$ keV, $M_{\eta_{\rm c}} = 2983.5 \pm 1.4 \phantom{|}^{+1.6}_{-3.6}$ MeV/$c^2$, $\Gamma_{\eta_{\rm c}} = 27.2 \pm 3.1 \phantom{|}^{+5.4}_{-2.6}$ MeV.Comment: 6 pages, 3 figure

Measurement of J/psi to eta_c gamma at KEDR

We present a study of the inclusive photon spectra from 5.9 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of radiative decay J/psi to eta_c gamma, eta_c width and mass. Our preliminary results are: M(eta_c) = 2979.4+-1.5+-1.9 MeV, G(eta_c) = 27.8+-5.1+-3.3 MeV, B(J/psi to eta_c gamma) = (2.34+-0.15+-0.40)%.Comment: To be published in Proceedings of the PhiPsi09, Oct. 13-16, 2009, Beijing, Chin

Measurement of B(J/psi->eta_c gamma) at KEDR

We present a study of the inclusive photon spectrum from 6.3 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/psi -> eta_c gamma, eta_c width and mass. Taking into account an asymmetric photon line shape we obtain: M(eta_c) = (2978.1 +- 1.4 +- 2.0) MeV/c^2, Gamma(eta_c) = (43.5 +- 5.4 +- 15.8) MeV, B(J/psi->eta_c gamma) = (2.59 +- 0.16 +- 0.31)%$.Comment: 6 pages, 1 figure. To be published in the proceedings of the 4th International Workshop on Charm Physics (Charm2010), October 21-24, 2010, IHEP, Beijin