Streams (preliminary full version). [Publisher information missing].

and seven threats facing online dating sites and the potential risk consumers face during this transition.

Die ZBW räumt Ihnen als Nutzerin/Nutzer das unentgeltliche, räumlich unbeschränkte und zeitlich auf die Dauer des Schutzrechts beschränkte einfache Recht ein, das ausgewählte Werk im Rahmen der unter

an innovative structure, as it combines 4-bit Sboxes with the AES MixColumn transformation, and has woken up the attention of cryptanalysts. Several security analyses have been published, in particular on the 64-bit key version. The best of these results could attack up to 10 rounds out of the total number

and settle some longstanding questions about their properties—in particular, we prove the existence of (symmetric monoidal) tensor products and sums and the non-existence of full categorical products or sums in the category of symmetric lenses. We then show how the methods of universal algebra can be applied

Abstract. Safety properties are crucial when verifying real-time concurrent systems. When reasoning parametrically, i.e., with unknown constants, it is of high interest to infer a set of parameter valuations consistent with such safety properties. We present here algorithms based on the “inverse method ” for parametric timed automata: given a reference parameter valuation, it infers a constraint such that, for any valuation satisfying this constraint, the system behaves the same as under the reference valuation in terms of traces, i.e., alternating sequences of locations and actions. Those algorithms do not guarantee the equality of traces, but are significantly quicker, synthesize larger sets of parameter valuations than the original inverse method, and still preserve various properties including safety properties. Those algorithms have been implemented in Imitator II and applied to examples of circuits and protocols. 1

We prove a number of Turán and Ramsey type stability results for cycles, in particular, the following one: Let n 4, 0 < 1=2 1=2n, and the edges of Kb(2 )nc be 2-colored so that no mononchromatic Cn exists. Then, for some q 2 ((1 )n 1; n) ; we may drop a vertex v so that in Kb(2 )nc v one of the colors induces Kq;b(2 )ncq1; while the other one induces Kq [Kb(2 )ncq1: We also derive the following Ramsey type result. If n is su ¢ ciently large and G is a graph of order 2n 1; with minimum degree (G) 2 106n; then for every 2-coloring of E (G) one of the colors contains cycles Ct for all t 2 [3; n]: 1

Much of the work that is labeled ‘descriptive ’ within linguistics comprises two activities, i.e. the collection of primary data and a (low-level) analysis of these data. These are indeed two separate activities as shown by the fact that the methods employed in each activity differ substantially. To date, the field concerned with the first activity — called ‘documentary linguistics ’ here — has received very little attention from linguists. It is proposed that documentary linguistics be conceived of as a fairly independent field of linguistic inquiry and practice which is no longer linked exclusively to the descriptive framework. A format for language documentations (in contrast to language descriptions) is presented and various practical and theoretical issues connected with this format are discussed. These include the rights of the individuals and communities contributing to a language documentation, the parameters for the selection of the data to be included in a documentation, and the assessment of the quality of such data. 1 1.

A well-established and fundamental insight in database the-ory is that negation (also known as complementation) tends to make queries difficult to process and difficult to reason about. Many basic problems are decidable and admit prac-tical algorithms in the case of unions of conjunctive queries, but become difficult or even undecidable when queries are allowed to contain negation. Inspired by recent results in fi-nite model theory, we consider a restricted form of negation, guarded negation. We introduce a fragment of SQL, called GN-SQL, as well as a fragment of Datalog with stratified negation, called GN-Datalog, that allow only guarded nega-tion, and we show that these query languages are compu-tationally well behaved, in terms of testing query contain-ment, query evaluation, open-world query answering, and boundedness. GN-SQL and GN-Datalog subsume a num-ber of well known query languages and constraint languages, such as unions of conjunctive queries, monadic Datalog, and frontier-guarded tgds. In addition, an analysis of standard benchmark workloads shows that most usage of negation in SQL in practice is guarded negation. 1.

Secure use of the BGLS [7] aggregate signature schemes is restricted to the aggregation of distinct messages (for the basic scheme) or per-signer distinct messages (for the enhanced, prepend-public-key version of the scheme). We argue that these restrictions preclude interesting applications, make