178,153 research outputs found
Germany Twice. Social Policy in two German States - Challenges, Similarities, separate Ways By Ciftci, R (Ciftci, Ridvan)
No full textCiftci R. Stefan Bollinger/Reiner Zilkenat (Hrsg.): Zweimal Deutschland. Soziale Politik in zwei deutschen Staaten – Herausforderungen, Gemeinsamkeiten, getrennte Wege. Buskow, Edition Bodoni, 2020 . Zeitschrift für Geschichtswissenschaft. 2021;69(11):996-998
Criterion for polynomial solutions to a class of linear differential equations of second order
No full textPT: JSource type: Electronic(1
Solutions for certain classes of the Riccati differential equation
No full textWe derive some analytic closed-form solutions for a class of Riccati equations y'(x) - lambda(0)(x) y(x) +/- y(2)(x) = +/- s(0)(x) where lambda(0)( x), s(0)( x) are C-infinity- functions. We show that if delta(n) = lambda(n)s(n-1) - lambda(n-1)s(n) = 0, where lambda(n) = lambda(')(n-1) + s(n-1) + lambda(0)lambda(n-1) and s(n) = s(n-1)(')+ s(0)lambda(k-1) , n = 1, 2, ... , then the Riccati equation has a solution given by y( x) = -/+ s(n-1)(x)/ lambda(n-1)(x). Extension to the generalized Riccati equation y'(x) + P(x) y(x) + Q(x) y(2)(x) = R(x) is also investigated
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
Structural investigations of phosphorus-nitrogen compounds. 6. Relationships between molecular parameters in per-X-substituted bridged spermine derivatives and basicity constants ??R of substituents
No full textA systematic study is reported of the products of the nucleophilic substitution reactions of the spermine-bridged cyclotriphosphazene, [N3P3X4(NHCH2CH2CH2N)CH2CH2]2 [where X = Cl (2a)], to give a number of new structures [(2b)-(2g)] in which X = OPh, [spiro-O(CH2)3O]0.5, Ph, NHPh, NC4H8 and NHBut, respectively. A comparison has been made between the sum of the substituent basicity constants, ΣαR, obtained in nitrobenzene solution, and ten molecular parameters of the N3P3 ring (the internal bond angles α, β, γ, δ and θ, and the P-N bond lengths a, b, c, d and e) as well as the difference between the bond lengths a and b, Δ(P-N). It is found that the systematic change in molecular parameters of compounds (2a)-(2g) is in line with changes in αR values, indicating the similarity in relative electron-releasing capacity of substituents X in the solid state and in solution. It is also found that the effect on molecular parameters of (2a)-(2g) with two X substituents in PX2 groups is greater than that for one X substituent in P(OR)X groups in an analogous series of compounds observed previously [Besli et al. (2002). Acta Cryst. B58, 1067-1073]
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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
- …
