Zusammenfassung Es wurden zwei empirische Studien durchgeführt. In der einen Studie konnten Internetnutzer ihr Suchverhalten aus ihrer Sicht in einer Online Umfrage beschreiben. Die Fragen orientieren sich an den Ergebnissen früherer Studien und sind durch neue Fragestellungen bei der Online Suche erweitert worden. In der anderen Studie wurden vier weltweit Datensätze von Suchanfragen generiert...

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We show that a strong form (the fully faithful version) of the generating hypothesis, introduced by Freyd in algebraic topology, holds in the derived category of a ring R if and only if R is von Neumann regular. This extends results of the second author [Loc07]. We also characterize rings for which the original form (the faithful version) of the generating hypothesis holds in the derived catego...

The aim of this paper is to study the Harnack type logarithmic submajorisation and Fuglede-Kadison determinant inequalities for operators in a finite von Neumann algebra. In particular, due Lin-Zhang [15] Yang-Zhang [27] are extended case

We give a new proof of a result of Ozawa showing that if a von Neumann subalgebra Q of a free group factor LFn, 2 ≤ n ≤ ∞ has relative commutant diffuse (i.e. without atoms), then Q is amenable.

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Let S be a finite nonabelian simple group, and let H be a subgroup of S . In this work, the dominion (in the sense of Isbell) of H in S in Var(S) is determined, generalizing an example of B.H. Neumann. A necessary and sufficient condition for H to be epimorphically embedded in S is obtained. These results are then extended to a variety generated by a family of finite nonabelian simple groups. S...

We continue the studies of the second author on regulated uniformly k-limited and regulated k-limited ET0L systems. We focus on the permitting and forbidding random context regulation. Especially, we establish some results on (regulated) propagating (uniformly) k-limited ET0L systems which were not solved in 2, 18, 21, 22]. Moreover, relations to recurrent programmed languages introduced by von...

We prove that every 2-local derivation from the algebra Mn(A)(n > 2) into its bimodule Mn(M) is a derivation, where A is a unital Banach algebra and M is a unital A-bimodule such that each Jordan derivation from A into M is an inner derivation, and that every 2-local derivation on a C*-algebra with a faithful traceable representation is a derivation. We also characterize local and 2-local Lie d...

It is well known that the C∗-algebra of an ordered pair of qubits is M2⊗M2. What about unordered pairs? We show in detail that M3⊕C is the C∗-algebra of an unordered pair of qubits. Then we use Schur-Weyl duality to characterize the C∗-algebra of an unordered n-tuple of d-level quantum systems. Using some further elementary representation theory and number theory, we characterize the quantum cy...