124,609 research outputs found
Non-Singular Method of Fundamental Solutions based on Laplace decomposition for 2D Stokes flow problems
No full textIn this paper, a solution of Two-Dimensional (2D) Stokes flow problem, subject to Dirichlet and fluid traction boundary conditions, is developed based on the Non-singular Method of Fundamental Solutions (NMFS). The Stokes equation is decomposed into three coupled Laplace equations for modified components of velocity, and pressure. The solution is based on the collocation of boundary conditions at the physical boundary by the fundamental solution of Laplace equation. The singularities are removed by smoothing them on disks around them. The derivatives on the boundary in the singular points are calculated through simple reference solutions. In NMFS, no artificial boundary is needed, as in the classical Method of Fundamental Solutions (MFS). Numerical examples include driven cavity flow on a square, analytically solvable solution on a circle and channel flow on a rectangle. The accuracy of the results is assessed by comparison with the MFS solution, and analytical solutions. The main advantage of the approach is its simple, boundary only meshless character of the computations, and possibility of straightforward extension of the approach to Three-Dimensional (3D) problems, moving boundary problems and inverse problems
Numerical modelling of coupled groundwater flow and heat extraction from subsoil.
No full textThe subsoil can be used to store or extract heat for cooling or heating buildings, respectively, via a ground-coupled heat pump (GCHP) and the Ground heat exchanger (GHE) commonly used consist of HPDE pipes. The present contribution deals with the role of groundwater flow in the
performance of GHEs installed in vertical boreholes. A mathematical model in 2D space is
introduced, comprising a pair of partial differential equations of parabolic and elliptic type for soil temperature and ground water velocity field, respectively. The equations have been solved numerically by mean of Difference Finite method and Finite Element Method. The numerical model has been validated by comparing the results with the solutions of Moving infinite line source (MILS) model. The soil temperatures established in a sand around GHE operating in heat mode are
calculated either assuming a uniform velocity field and by taking into account the correct seepage around the GHEs to investigate how much the proper modelling of groundwater flow around the borehole affects the results
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
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The effect of gas-surface model on thermal creep flow
No full textNumerical analysis of the nonlinear rarefied gas flow caused by temperature gradient in a direction tangential to the wall through a planar channel of finite length is carried out based on the S- model kinetic equation under a range of Knudsen number from free-molecular to slip regime. Cercignani- Lampis solid boundary condition is chosen at channel walls. An implicit scheme is applied; the algorithm is optimized via massive parallelization in both physical and velocity spaces. Results showed that the gas-surface scattering model plays distinguished role for highly rarefied conditions
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
Dr. Edwin Wright Collection: Author Unknown
No full textNotes - The author relates several short stories about his neighbours including Alex McDonell, homesteading and life around Meanook and Athabasca (1 page
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Nonlinear stability analysis of fluid flow with viscous dissipation in a porous channel
No full textThe nonlinear convective instability of flow in a fluid saturated rectangular porous channel of arbitrary aspect ratio is here investigated by taking into account the effect of viscous dissipation. A laminar throughflow of constant velocity is assumed. The system is characterized by a unique source of thermal instability identified in the internal heat generation due to the viscous dissipation. The nonlinear analysis is performed by means of the generalized integral transform technique (GITT). The results obtained are compared with those coming from the linear analysis carried out numerically by means of the normal modes method
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
No full textThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
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