Nivat's processes and their synchronization

AbstractThis short paper retraces how the notion of synchronization of processes introduced by Maurice Nivat in 1979 has evolved over more than 20 years

Teens Acting Against Violence (TAAV) Program Evaluation

Teens Acting Against Violence (TAAV) is a violence prevention and youth empowerment program at the Tundra Women’s Coalition (TWC) for teenagers living in Bethel, Alaska. Participation is voluntary and open for any interested teens aged 12-18. TWC and TAAV partnered with the University of Alaska Anchorage (UAA) Justice Center to conduct an evaluation of the TAAV program through a one-time survey of former and current adult members (over 18 years of age) of TAAV. Pursuant to TAAV objectives, the focus of the evaluation was placed on examining efforts in the areas of domestic violence and sexual assault prevention, building healthy relationships, encouraging sobriety, and suicide prevention.Tundra Women’s CoalitionTable of Contents / Acknowledgments / Executive Summary / Section I. Introduction and Background / Section II. Methodology / Section III. Program Satisfaction / Section IV. TAAV Staff / Section V. Cultural Considerations / Section VI. TAAV Activities / Section VII. TAAV Impacts / Section VIII. Life Skills / Section IX. Self-perceptions / Section X. Interpersonal Relationships / Section XI. Bystander Intervention / Section XII. High-risk Behaviors / Section XIII. Member Feedback / Section XIV. Conclusion and Recommendations / Appendix A: TAAV Survey / Appendix B: List of Survey Resources / Appendix C: Data Table

An algebraic characterization of transition system equivalences

AbstractI. Castellani (1987, J. Comput. System Sci. 34, 210–235) has shown that observation equivalence of transition systems could be characterized by particular reductions: systems are equivalent if, and only if, they can be reduced to the same form. Moreover, every transition system has a minimal reduced form. We extend these results to logical equivalence, by an algebraic interpretation of temporal logics: we characterize logical equivalence of transition systems by particular reductions (saturating quasi-homomorphisms) or their power algebras of sets of states and paths and prove that every power algebra has a minimal reduced form. We then offer alternative proofs for logical characterizations of observation equivalence: in particular we apply our method to prove M. Hennessy and C. Stirling's (1984, “Lecture Notes in Comput. Sci. Vol. 176,” pp. 301–311, Springer-Verlag, New York/Berlin) result that “Future Perfect” logic characterizes observation equivalence of generalized transition systems, i.e., systems whose infinite behaviours are restricted by arbitrary fairness constraints

Un théorème de duplication pour les forêts algébriques

On caractérise les forêts algébriques dont tous les arbres sont de la forme α(t, t). On utilise cette caractérisation pour montrer que la classe des forêts algébriques n'est par fermée par homomorphisme non linéaire, et pour montrer qu'il existe des forêts reconnaissables généralisées, au sens de Maibaum, dont le feuillage n'est pas une forêt algébrique

An algebraic characterization of observational equivalence

AbstractWe show that observational equivalence can be characterized by saturating homomorphisms (with respect to Hennessy-Milner logic), thus bringing together results developed independently by Castellani and by Arnold and Dicky on characterizations of transition system equivalences. We take this opportunity to compare Castellani's abstraction homomorphisms and Arnold-Dicky's saturating homomorphisms. It turns out that they are very similar notions: their difference in formulation is partly due to the fact that abstraction homomorphisms were defined on a restricted class of transition systems

Schutz gegen industrielle Schadstoffe durch den ABC-Schutzfilter 74

This paper reports protection performance data of the NBC-canister (NBC-SF 74) against some important industrial agents under various experimental conditions (humidity, challenge concentration). The principles of construction and function of the NBC-SF 74 are explained, and a description of the measuring apparatus is given. The protection capabilities against different compounds are discussed, and for 25 substances the evaluated data listed. For challenge concentrations below 0.5 vol.-% and agents with b.p. > 65°, sufficient protection levels are observed. The protection levels against industrial agents with low b.p. are lower and must be carefully evaluated as a function of the prevailing environment conditions

Affine completeness of some free binary algebras

A function on an algebra is congruence preserving if, for any congruence, it maps pairs of congruent elements onto pairs of congruent elements. An algebra is said to be affine complete if every congruence preserving function is a polynomial function. We show that the algebra of (possibly empty) binary trees whose leaves are labeled by letters of an alphabet containing at least one letter, and the free monoid on an alphabet containing at least two letters are affine complete

Survey on Solar X-ray Flares and Associated Coherent Radio Emissions

The radio emission during 201 selected X-ray solar flares was surveyed from 100 MHz to 4 GHz with the Phoenix-2 spectrometer of ETH Zürich. The selection includes all RHESSI flares larger than C5.0 jointly observed from launch until June 30, 2003. Detailed association rates of radio emission during X-ray flares are reported. In the decimeter wavelength range, type III bursts and the genuinely decimetric emissions (pulsations, continua, and narrowband spikes) were found equally frequently. Both occur predominantly in the peak phase of hard X-ray (HXR) emission, but are less in tune with HXRs than the high-frequency continuum exceeding 4 GHz, attributed to gyrosynchrotron radiation. In 10% of the HXR flares, an intense radiation of the above genuine decimetric types followed in the decay phase or later. Classic meter-wave type III bursts are associated in 33% of all HXR flares, but only in 4% are they the exclusive radio emission. Noise storms were the only radio emission in 5% of the HXR flares, some of them with extended duration. Despite the spatial association (same active region), the noise storm variations are found to be only loosely correlated in time with the X-ray flux. In a surprising 17% of the HXR flares, no coherent radio emission was found in the extremely broad band surveyed. The association but loose correlation between HXR and coherent radio emission is interpreted by multiple reconnection sites connected by common field line

Noise gates for decoherent quantum circuits

A major problem in exploiting microscopic systems for developing a new technology based on the principles of Quantum Information is the influence of noise which tends to work against the quantum features of such systems. It becomes then crucial to understand how noise affects the evolution of quantum circuits: several techniques have been proposed among which stochastic differential equations (SDEs) can represent a very convenient tool. We show how SDEs naturally map any Markovian noise into a linear operator, which we will call a noise gate, acting on the wave function describing the state of the circuit, and we will discuss some examples. We shall see that these gates can be manipulated like any standard quantum gate, thus simplifying in certain circumstances the task of computing the overall effect of the noise at each stage of the protocol. This approach yields equivalent results to those derived from the Lindblad equation; yet, as we show, it represents a handy and fast tool for performing computations, and moreover, it allows for fast numerical simulations and generalizations to non Markovian noise. In detail we review the depolarizing channel and the generalized amplitude damping channel in terms of this noise gate formalism and show how these techniques can be applied to any quantum circuit.Comment: 10 pages, 4 figures: journal reference added + some typos correcte