1,721,430 research outputs found
Stable–unstable flow of geothermal fluids in fractured rock
No full textDensity-driven geothermal flow in 3-D fractured rock is investigated and compared with density-driven haline flow. For typical matrix and fracture hydraulic conductivities, haline flow tends to be unstable (convecting) while geothermal flow is stable (non-convecting). Thermal diffusivity is generally three orders of magnitude larger than haline diffusivity and, as a result, large heat conduction diminishes growth of geothermal instabilities while low mass diffusion enables formation of unstable haline 'fingering' within fractures. A series of thermal flow simulations is presented to identify stable and unstable conditions for a wide range of hydraulic conductivities for matrix and fractures. The classic Rayleigh stability criterion can be applied to classify these simulations when fracture aperture is very small. However, the Rayleigh criterion is not applicable when the porous matrix hydraulic conductivity is very small, because stabilizing fracture-matrix heat conduction is independent of matrix hydraulic conductivity. In that case, the numerically estimated critical fracture conductivity is nine orders of magnitude larger than the theoretically calculated critical fracture conductivity based on Rayleigh theory. The numerical stability analysis presented here may be used as a guideline to predict if a geothermal system in 3-D fractured rock is stable or unstable
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
DIMENSI PARTISI PADA GRAF C_m ∗ K_n , GRAF C_m[P_n ], DAN GRAF t-FOLD WHEEL
Full text linkDiberikan G adalah graf terhubung dengan himpunan vertex V (G) = {v_1, . . . , v_n} dan himpunan edge E(G) = {e_1, ...,}. Vertex-vertex tersebut dibagi menjadi k−partisi, dinotasikan dengan S_1, S_2, . . . , S_n. Himpunan Pi ={S_1, S_2, . . . ,S_k} adalah himpunan k−partisi terurut. Representasi untuk setiap vertex V (G) terhadap Pi adalah jarak minimum dari suatu vertex ke S dengan 1 ≤ i ≤ k, dinotasikan dengan r(v|Pi) = (d(v, S_1), d(v, S_2), . . . , d(v, S_k)). Jika setiap vertex memiliki representasi yang berbeda, maka Pi disebut partisi pembeda dengan k−partisi pembeda. Kardinalitas minimum dari k−partisi pembeda terhadap V (G) disebut dimensi partisi dari G, dinotasikan dengan pd(G). Dalam penelitian ini ditentukan dimensi partisi pada kelas graf C_m ∗ K_n C_m[P_n], dan graf t-fold wheel. Diperoleh hasil penelitian, yaitu dimensi partisi untuk graf C_m ∗ K_n C_m[P_n], dan graf t-fold wheel. Untuk graf C_m ∗ K_n, diperoleh pd(C_m ∗ K_n) = n untuk m, n ≥ 3. Untuk graf C_m[P_n], diperoleh 4 ≤ pd(C_m[P_n]) ≤ 2n − 2, dengan "=" dicapai hanya jika n = 2, m ≥ 4 dan n > 4, m =4. Untuk graf t-fold wheel, diperoleh t ≤ pd(W_n^t) ≤ t+1 + ⌈2log((n+t)/t)⌉, untuk n≥ 3 dan t ≥ 1
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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