Narrow-domain Short Texts Clustering Algorithm

In this paper, we describe the algorithm of narrow-domain short texts clustering, which is based on terms’ selection and modification of k-means algorithm. Our approach was tested on collections: CICling–2002 and SEPLIN-CICling. Results of tests and conclusions are presented

Actual vitamins and calcium consumption and their plasma concentrations in osteoarthritis patients

The aim of the study was to investigate vitamins, calcium actual consumption and supplying during osteoarthritis. By «random-control» method 162 pairs of osteoarthritis patients in the age of 57,98±10,78 years were formed. Actual feeding was investigated by analyzing questionnaires concerning food-stuff consumption during one month. These data were used to calculate vitamin A, B2, С, E, p-carotene, calcium daily consumption. 35% patients of the random group and 68 patients of the control group were tested for plasma concentrations of the above mentioned substances. Research revealed vitamin A, B2, C, calcium actual consumption insufficiency compared to controlled samples. Vitamins density calculations made possible to take a fresh look on vitamin C, B2, calcium consumption during osteoarthritis. Vitamin C, B2, 13- carotene, calcium showed the most evident concentration insufficiency during osteoarthritis. Performed analyses of these results led to proposals concerning vitamins and calcium consumption particularities caused by osteoarthritis.Проведено исследование, целью которого явилось изучение фактического потребления и обеспеченности витаминами и кальцием при остеоартрозе (ОА). Методом «случай-контроль» сформировано 162 пары при ОА в возрасте 57,98±10.78 года. Изучение фактического питания проведено методом изучения частоты потребления пищевых продуктов в течение месяца с использованием анкеты. На основании данных анализа частоты потребления пищи рассчитывали суточное потребление витаминов А, В2, С, Е, (3-каротина и кальция. В 35-ти процентной случайной выборке и у 68 человек в контроле определено содержание этих витаминов в плазме крови. В результате исследования установлено, что фактическое питание больных ОА в абсолютном значении по сравнению с контрольными копиями обеднено витамином А, С, В2 и кальцием. Расчет плотности витаминов позволил взглянуть иначе на потребление витамина С, В2 и кальция при ОА. Наибольшие концентрационные различия в сторону недостаточной обеспеченности выявлены по витамину С, (3-каротину, рибофлавину и кальцию при ОА. Проведенный анализ полученных результатов позволил предварительно сформулировать особенности потребления витаминов и кальция при ОА

Shower approach in the simulation of ion scattering from solids

An efficient approach for the simulation of ion scattering from solids is proposed. For every encountered atom, we take multiple samples of its thermal displacements among those which result in scattering with high probability to finally reach the detector. As a result, the detector is illuminated by intensive "showers", where each event of detection must be weighted according to the actual probability of the atom displacement. The computational cost of such simulation is orders of magnitude lower than in the direct approach and a comprehensive analysis of multiple and plural scattering effects becomes possible. We use the new method for two purposes. First, the accuracy of the approximate approaches, developed mainly for ion-beam structural analysis, is verified. Second, the possibility to reproduce a wide class of experimental conditions is used to analyze some basic features of ion-solid collisions: the role of double violent collisions in low-energy ion scattering; the origin of the "surface peak" in scattering from amorphous samples; the low-energy tail in the energy spectra of scattered medium-energy ions due to plural scattering; the degradation of blocking patterns in 2D angular distributions with increasing depth of scattering. As an example of simulation for ions of MeV energies, we verify the time-reversibility for channeling/blocking of 1 MeV protons in a W crystal. The possibilities of analysis that our approach offers may be very useful for various applications in particular for structural analysis with atomic resolution.Comment: 16 pages, 9 figures. Finally published version; large parts reformulated, Fig. 9 and references adde

Single spin asymmetry measurements for π0\pi^0 inclusive productions in p+p↑→π0+Xp+p_{\uparrow} \to \pi^0 + X and \pi^-+\p_{\uparrow}\to \pi^0+X reactions at 70 and 40 GeV respectively

The inclusive $\pi^0$ asymmetries were measured in reactions $p+p\uparrow \to \pi^0+X$ and $\pi^-+p\uparrow \to \pi^0+X$ at 70 and 40 GeV/c respectively. The measurements were made at the central region (for the first reaction) and asymmetry is compatible with zero in the entire measured $p_T$ region. For the second reaction the asymmetry is zero for small $x_F$ region ($-0.4<x_F<-0.1, 0.5<p_T(GeV/c) <1.5$) and increases with growth of $\mid x_F\mid$. Averaged over the interval $-0.8<x_F<-0.4, 1<p_T(GeV/c)<2$ the asymmetry was $-(13.8\pm 3.8)$.Comment: 4 pages, 2 figures; Presented at SPIN-2004 at Trieste, October 10-16,200

First study of radiation hardness of lead tungstate crystals at low temperatures

The electromagnetic calorimeter of PANDA at the FAIR facility will rely on an operation of lead tungstate (PWO) scintillation crystals at temperatures near -25 deg.C to provide sufficient resolution for photons in the energy range from 8 GeV down to 10 MeV. Radiation hardness of PWO crystals was studied at the IHEP (Protvino) irradiation facility in the temperature range from room temperature down to -25 deg.C. These studies have indicated a significantly different behaviour in the time evolution of the damaging processes well below room temperature. Different signal loss levels at the same dose rate, but at different temperatures were observed. The effect of a deep suppression of the crystal recovery process at temperatures below 0 deg.C has been seen.Comment: 10 pages 7 figure