262,772 research outputs found
Pseudo-differential operators, heat calculus and index theory of groupoids satisfying the Lauter-Nistor condition
No full textIn this thesis, we study singular pseudo-differential operators defined by groupoids
satisfying the Lauter-Nistor condition, by a method parallel to that of manifolds
with boundary and edge differential operators. The example of the Bruhat sphere
is studied in detail. In particular, we construct an extension to the calculus of
uniformly supported pseudo-differential operators that is analogous to the calculus
with bounds defined on manifolds with boundary. We derive a Fredholmness criterion
for operators on the Bruhat sphere, and prove that their parametrices up to compact
operators lie inside the extended calculus; we construct the heat kernel of perturbed
Laplacian operators; and prove an Atiyah-Singer type renormalized index formula
for perturbed Dirac operators on the Bruhat sphere using the heat kernel method
Approximate solutions to second order parabolic equations I: analytic estimates
No full text1 online resource (PDF, 28 pages)Constantinescu, Radu; Costanzino, Nicola; Mazzucato, Anna; Nistor, Victor. (2009). Approximate solutions to second order parabolic equations I: analytic estimates. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/180117
Ion I. Nistor and the Development of Romanian Historiography in Bucovina to the Union of 1918
No full textAbstract:
The preference of Romanians in Bukovina for history and language is a reflection of their national militancy, which characterized the end of the XIXth century. Subjected to a foreign government, that changed structures and mentalities, the Romanians have found in language and history some useful arguments for preserving their national values and recovering their collective dignity. Many scholars were involved in the forging of Romanian consciousness. The following study highlights aspects of biographical and historiographycal activity of Ion Nistor. It also presents the historian’s contribution to the development of Romanian historiography in Bukovina, in two critical periods: the period before the World War I, when the national movement had been resized, depending on historical needs, and the period during 1914-1918, focusing on unification of Bukovina with the Romanian Kingdom, including the consequence of the next events in December 1918. Although there are some details about the historian’s life, this study is emphasized in the role of Nistor to the professionalization of the Romanian historiography, which was specific to the late nineteenth century and early twentieth century
A new impact test for the identification of a dynamic crack propagation criterion using a gas-gun device
No full textThe modelling of damage and fracture behaviour under high rates of loadings for metallic structures presents the more and more interests for engineering design, especially for crash phenomena.In order to perform a numerical simulation of such phenomena a crack propagation criterion must be identified using adapted laboratory tests. The objective of this paper is to present a new impact test intended for the identification of a cohesive crack criterion implemented into a home-made FEM code based on Extended Finite ElementMethod. Therefore, a double-notched specimen is impacted using a gas-gun device in order to obtain different crack paths depending on projectile speed. A post-impact macro-photographic observation allows to measure the crack path, the angles and the advancing length. These experimental results are used as input responses in the identification procedure for determining the crack cohesive criterion parameters. Some experimental results, for an aluminium alloy crack criterion identification, are presented to illustrate the proposed approach
Ion I. Nistor in Romanian Politics, Scholarship, and Culture, 1919-1933
No full textIn the first decades after unification in 1918, Ion Nistor – the remarkable historian and leader of the movement for defending the historical rights of Romanians in Bukovina - was involved in the process of consolidation of the Great Romania. In an era of vitality and creativity, as of disputes and divisions, he was asked to contribute to the so-called "full integration of Bucovina in the new Romanian state." The following study points out some characteristics of Nistor’s activity between 1919-1933, focusing on the political principles which inspired him in his career, as well as the main cultural achievements
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Haemodiafiltration, haemofiltration and haemodialysis for end-stage kidney disease
No full textBackgroundConvective dialysis modalities (haemofiltration (HF), haemodiafiltration (HDF), and acetate-free biofiltration (AFB)) removed excess body fluid across the dialysis membrane with positive pressure and accumulated middle-and larger-size accumulated solutes more efficiently than haemodialysis (HD). This increased larger solute removal combined with use of ultra-pure dialysis fluid in convective dialysis is hypothesised to reduce the frequency and severity of symptoms during dialysis as well as improve clinical outcomes. Convective dialysis therapies (HDF and HF) are associated with lower mortality compared to diffusive therapy (HD) in observational studies. This is an update of a review first published in 2006.ObjectivesTo compare convective (HF, HDF, or AFB) with diffusive (HD) dialysismodalities on clinical outcomes (mortality, major cardiovascular events, hospitalisation and treatment-related adverse events) in men and women with end-stage kidney disease (ESKD).Search methodsWe searched the Cochrane Renal Group's Specialised Register (to 18 February 2015) through contact with a Trials' Search Co-ordinator using search terms relevant to this review.Selection criteriaWe included randomised controlled trials comparing convective therapy (HF, HDF, AFB) with another convective therapy or diffusive therapy (HD) for treatment of ESKD.Data collection and analysisTwo independent authors identified studies, extracted data and assessed study risk of bias. We summarised treatment effects using the random effects model. We reported results as a risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous data together with 95% confidence intervals (CI). We assessed for heterogeneity using the Chi(2) test and explored the amount of variation in treatment estimates beyond that expected by chance using the I-2 statistic.Main resultsTwenty studies comprising 667 participants were included in the 2006 review. In that review, therewas insufficient evidence of treatment effects on major clinical outcomes to draw clinically meaningful conclusions. Searching to February 2015 identified 40 eligible studies comprising 3483 participants overall. In total, 35 studies (4039 participants) compared HF, HDF or AFB with HD, three studies (54 participants) compared AFB with HDF, and three studies (129 participants) compared HDF with HF.Risks of bias in all studies were generally high resulting in low confidence in estimated treatment effects. Convective dialysis had no significant effect on all-cause mortality (11 studies, 3396 participants: RR 0.87, 95% CI 0.72 to 1.05; I-2 = 34%), but significantly reduced cardiovascular mortality (6 studies, 2889 participants: RR 0.75, 95% CI 0.61 to 0.92; I-2 = 0%). One study reported no significant effect on rates of nonfatal cardiovascular events (714 participants: RR 1.14, 95% CI 0.86 to 1.50) and two studies showed no significant difference in hospitalisation (2 studies, 1688 participants: RR 1.23, 95% CI 0.93 to 1.63; I-2 = 0%). One study reported rates of hypotension during dialysis were significantly reduced with convective therapy (906 participants: RR 0.72, 95% CI 0.66 to 0.80). Adverse events were not systematically evaluated inmost studies and data for health-related quality of life were sparse. Convective therapies significantly reduced predialysis levels of B-2 microglobulin (12 studies, 1813 participants: MD -5.55 mg/dL, 95% CI -9.11 to -1.98; I-2 = 94%) and increased dialysis dose (Kt/V urea) (14 studies, 2022 participants: MD 0.07, 95% CI -0.00 to 0.14; I-2 = 90%) compared to diffusive therapy, but results across studies were very heterogeneous. Sensitivity analyses limited to studies comparing HDF with HD showed very similar results. Directly comparative data for differing types of convective dialysis were insufficient to draw conclusions.Studies had important risks of bias leading to low confidence in the summary estimates and were generally limited to patients who had adequate dialysis vascular access.Authors' conclusionsConvective dialysismay reduce cardiovascular but not all-causemortality and effects on nonfatal cardiovascular events and hospitalisation are inconclusive. However, any treatment benefits of convective dialysis on all patient outcomes including cardiovascular death are unreliable due to limitations in study methods and reporting. Future studies which assess treatment effects of convection dose on patient outcomes including mortality and cardiovascular events would be informative
Studiu privind posibilitatea implementarii balance scorecard-ului in universitati
No full textBalanced Scorecard is a new control tool in public entities, especially in universities. The aim of this paper is to analyze the possibility of implementation in Romanian universities. At an international level, this concept was used at the beginning by the private sector, followed by its usage by the public sector as well. In universities of the Anglo – Saxon states, there have been debates on the subject for a long period of time in relation to the opportunity of introducing this concept; these debates have been supported by pro and against arguments. At a national level, this concept is virtually unknown in the higher education state institution system. Through the present paper, we would like to test the opportunity of introducing the concept starting from the identification at a global level of the conditions and regulations specific to the Balanced Scorecard (BSC) concept. Our results will present the first overview of this new subject, which is not yet developed in Romania.Balanced Scorecard Concept, Public University, Managerial Accounting
High-resolution projections of evapotranspiration and water availability for Europe under climate change
No full textEurope-wide high-resolution (1 km) gridded data of estimates of monthly and annual potential evapotranspiration (ET0), annual actual evapotranspiration (AET0) and water availability for a climate normal period largely preceding an anthropogenic warming signal (1961-1990) and for two CMIP5 multimodel future projections (2011-2040 and 2041-2070). In the ET0 calculation, the monthly and annual heat index I and annual α parameter were estimated following the Thornthwaite method, and AET0 was calculated using the Budyko approach.
For citations and more details, please refer to "High-resolution projections of evapotranspiration and water availability for Europe under climate change" by Ştefan Dezsi, Marcel Mândrescu, Dănuţ Petrea, Praveen Kumar Rai, Andreas Hamann, Mărgărit-Mircea Nistor, published in International Journal of Climatology (https://doi.org/10.1002/joc.5537)</p
Incorporating the Basic Elements of a First-degree Fuzzy Logic and Certain Elments of Temporal Logic for Dynamic Management Applications
No full textThe approximate reasoning is perceived as a derivation of new formulas with the corresponding temporal attributes, within a fuzzy theory defined by the fuzzy set of special axioms. For dynamic management applications, the reasoning is evolutionary because of unexpected events which may change the state of the expert system. In this kind of situations it is necessary to elaborate certain mechanisms in order to maintain the coherence of the obtained conclusions, to figure out their degree of reliability and the time domain for which these are true. These last aspects stand as possible further directions of development at a basic logic level. The purpose of this paper is to characterise an extended fuzzy logic system with modal operators, attained by incorporating the basic elements of a first-degree fuzzy logic and certain elements of temporal logic.Dynamic Management Applications, Fuzzy Reasoning, Formalization, Time Restrictions, Modal Operators, Real-Time Expert Decision System (RTEDS)
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