138 research outputs found

    Static and dynamic mechanical characterization of cross-linked polyethylene foams: The effect of density

    Get PDF

    Development of automatic intelligent system for on-line voltage security control of power systems

    Get PDF
    The majority of recent large-scale blackouts have been caused by voltage instability. A prompt on-line assessment of voltage stability for preventive corrective control of electric power systems is one of the key objectives for Control centers. The use of classical approximation methods alone is complicated. Therefore, several modified methods combined with machine learning algorithms enabling security assessment in real time have been proposed over the last years. The paper presents an automatic intelligent system for on-line voltage security control, which is based on the model of decision trees Proximity Driven Streaming Random Forest (PDSRF). In this case, the combination of original properties of PDSRF and capabilities of L-index as a target vector makes it possible to provide the functions of dispatcher warning, localization of critical nodes, and ensure direct interaction with the security automation systems. The efficiency of the proposed system was demonstrated using various test schemes of IEEE

    Remote Prophylaxis of Social and Educational Adaptation of University International Entrants in Total Pandemic

    Get PDF
    The relevance of the study is due to the trends of the global pandemic, which provoked an extremal transition of all areas of higher education to distance learning, as the only possible way to work with domestic and international entrants and students. In addition, the trends of the pandemic in the current educational environment also determine the special need to develop remote mechanisms for a prophylaxis approach to solving the problems of social and educational adaptation of international entrants – future University students. In this regard, this article is aimed at identifying the features of remote prophylaxis of social and educational adaptation of entrants. The article reveals the transformation of social and educational adaptation of international entrants in the global pandemic; defines the structure and content of remote prophylaxis of social and educational adaptation of international University entrants in the global pandemic. Based on the results of the research, the authors of the article substantiate the prophylaxis model of the educational and software complex for remote prophylaxis of social and educational adaptation of University international entrants. The effectiveness of the model is proved by the results of its use in the process of remote social and educational adaptation of University international entrants in the context of a global pandemic. The materials of the article have practical application and can be useful in the development and implementation of various methods and practices of social and educational adaptation of international entrants – future University students in the context of a global pandemic. It is recommended for University teachers and students, methodologists, curators, Tutors

    Current Helicity and Twist as Two Indicators of The Mirror Asymmetry of solar Magnetic Fields

    Full text link
    A comparison between the two tracers of magnetic field mirror asymmetry in solar active regions, twist and current helicity, is presented. It is shown that for individual active regions these tracers do not possess visible similarity while averaging by time over the solar cycle, or by latitude, reveals similarities in their behaviour. The main property of the dataset is anti-symmetry over the solar equator. Considering the evolution of helical properties over the solar cycle we find signatures of a possible sign change at the beginning of the cycle, though more systematic observational data are required for a definite confirmation. We discuss the role of both tracers in the context of the solar dynamo theory.Comment: 14 pages, 6 figure

    Clinical significance of genetic aberrations in secondary acute myeloid leukemia

    Get PDF
    The study aimed to identify genetic lesions associated with secondary acute myeloid leukemia (sAML) in comparison with AML arising de novo (dnAML) and assess their impact on patients' overall survival (OS). High-resolution genotyping and loss of heterozygosity mapping was performed on DNA samples from 86 sAML and 117 dnAML patients, using Affymetrix Genome-Wide Human SNP 6.0 arrays. Genes TP53, RUNX1, CBL, IDH1/2, NRAS, NPM1, and FLT3 were analyzed for mutations in all patients. We identified 36 recurrent cytogenetic aberrations (more than five events). Mutations in TP53, 9pUPD, and del7q (targeting CUX1 locus) were significantly associated with sAML, while NPM1 and FLT3 mutations associated with dnAML. Patients with sAML carrying TP53 mutations demonstrated lower 1-year OS rate than those with wild-type TP53 (14.3% +/- 9.4% vs. 35.4% +/- 7.2%; P = 0.002), while complex karyotype, del7q (CUX1) and del7p (IKZF1) showed no significant effect on OS. Multivariate analysis confirmed that mutant TP53 was the only independent adverse prognostic factor for OS in sAML (hazard ratio 2.67; 95% CI: 1.335.37; P = 0.006). Patients with dnAML and complex karyotype carried sAML-associated defects (TP53 defects in 54.5%, deletions targeting FOXP1 and ETV6 loci in 45.4% of the cases). We identified several co-occurring lesions associated with either sAML or dnAML diagnosis. Our data suggest that distinct genetic lesions drive leukemogenesis in sAML. High karyotype complexity of sAML patients does not influence OS. Somatic mutations in TP53 are the only independent adverse prognostic factor in sAML. Patients with dnAML and complex karyotype show genetic features associated with sAML and myeloproliferative neoplasms. Am. J. Hematol., 2012

    Follow-up of breast cancer in primary care vs specialist care: results of an economic evaluation

    Get PDF
    A randomized controlled trial (RCT) comparing primary-care-centred follow-up of breast cancer patients with the current standard practice of specialist-centred follow-up showed no increase in delay in diagnosing recurrence, and no increase in anxiety or deterioration in health-related quality of life. An economic evaluation of the two schemes of follow-up was conducted concurrent with the RCT. Because the RCT found no difference in the primary clinical outcomes, a cost minimization analysis was conducted. Process measures of the quality of care such as frequency and length of visits were superior in primary care. Costs to patients and to the health service were lower in primary care. There was no difference in total costs of diagnostic tests, with particular tests being performed more frequently in primary care than in specialist care. Data are provided on the average frequency and length of visits, and frequency of diagnostic testing for breast cancer patients during the follow-up period. © 1999 Cancer Research Campaig
    corecore