520 research outputs found
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
FORMATION OF VALUABLE-SENSITIVE BASES OF THE PEDAGOGICAL PROFESSION IN THE UNIVERSITY
The authors of the article present a study of the features of the value-semantic bases of the activity of students of a pedagogical university of 1 - 5 courses, describe the dynamics of the phenomenon studied during the training. The authors comprehend the relevance of this problem in the context of modernizing pedagogical education. Based on the leading principles of the concept of professional development of personality, the authors describe one of the components of professional identity - value, the features of the crisis of the third year and the leading terminal and instrumental values during the professional training of students in the university
IDENTITY CRISIS: PROBLEMS OF TEACHER FORMATION
The article is devoted to the problem of the crisis of personal and social identities as significant components of the “existential crisis” in the context of social transformation. Based on the ideas of existential phenomenology, the authors reveal the changing nature of the teacher identification system, suggest highlighting the notion of the “teacher identity” and consider the crisis nature of its formation. The authors revealed that the process of identifying future teachers is carried out in stages through the subsequent change of academic, educational, professional and professional identity. The transition from one type of identity to another occurs on the basis of identity crises.
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
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
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
Stop-words in keyphrase extraction problem
Keyword extraction problem is one of the most significant tasks in information retrieval. High-quality keyword extraction sufficiently influences the progress in the following subtasks of information retrieval: classification and clustering, data mining, knowledge extraction and representation, etc. The research environment has specified a layout for keyphrase extraction. However, some of the possible decisions remain uninvolved in the paradigm. In the paper the authors observe the scope of interdisciplinary methods applicable to automatic stop list feeding. The chosen method belongs to the class of experiential models. The research procedure based on this method allows to improve the quality of keyphrase extraction on the stage of candidate keyphrase building. Several ways to automatic feeding of the stop lists are proposed in the paper as well. One of them is based on provisions of lexical statistics and the results of its application to the discussed task point out the non-gaussian nature of text corpora. The second way based on usage of the Inspec train collection to the feeding of stop lists improves the quality considerably
Comparison of Radiation Damage in Lead Tungstate Crystals under Pion and Gamma Irradiation
Studies of the radiation hardness of lead tungstate crystals produced by the
Bogoroditsk Techno-Chemical Plant in Russia and the Shanghai Institute of
Ceramics in China have been carried out at IHEP, Protvino. The crystals were
irradiated by a 40-GeV pion beam. After full recovery, the same crystals were
irradiated using a -ray source. The dose rate profiles along
the crystal length were observed to be quite similar. We compare the effects of
the two types of radiation on the crystals light output.Comment: 10 pages, 8 figures, Latex 2e, 28.04.04 - minor grammatical change
Long-chain alkyl esters of O,O-dialkyl dithiophosphoric and thionophosphoric acids prepared on the basis of red phosphorus, elemental sulfur, alcohols, and industrial fractions of higher monoolefins
Copyright © Taylor & Francis Group, LLC. Mixtures of long chain S-alkyl O,O-dialkyl dithiophosphates, and O-alkyl O,O-dialkyl thionophosphates were obtained by the reaction of red phosphorus with elemental sulfur, alcohols, and industrial fractions of C16-C18 and C20-C26 of higher olefins in the presence of Lewis acid catalysts. The products obtained possess high anticorrosion activities toward mild steel
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