A verification concept for SDL systems and its application to the Abracadabra protocol

SDL is a specification language to specify distributed systems. Especially it is suitable for communication protocols. In some cases however it is not enough to describe just the behaviour of a protocol, but there are formulated some additional properties as requirements of the SDL system. A formalism convenient to describe them is for example first order logic. Our approach is to prove such properties with methods of automated reasoning after transforming the SDL specification into a first order logic specification. The proofs are done with the program verification system Tatzelwurm, especially with its prover. Practical experience shows that it is convenient to do a proof in two steps. In the first step the behaviour of the system is calculated out of the behaviour of the agents. The proofs of this step is independent of the property to prove. In this report we give a proof methods containing instructions how the arguments are applied during these proofs. It is shown how reachability analysis is done during a formal proof and how fairness arguments are applied. The report contains two papers, where the first one describes the formal basis of the method and shows the proof obligations occurring verifying a communication protocol. The second paper shows how some tedious tasks can be done more elegant using rewrite rules and recursive equations. In the appendix we give two examples out of the verification of the Abracadabra Protocol

Zeitliche Diversität in der alternden Stadtgesellschaft: Lösungsansätze und zeitpolitische Implikationen

Die Alterung der Bevölkerung wirft die Frage auf, inwieweit die öffentlichen Räume der Stadt nicht nur in baulicher und verkehrstechnischer Hinsicht den Bedürfnissen dieser wachsenden Personengruppe entsprechen müssen, sondern auch in Bezug auf die dort anzutreffenden Zeitstrukturen. Der Beitrag geht von der Vermutung aus, dass im Zuge der allgemeinen gesellschaftlichen Beschleunigungstendenz ein Großteil der im Alltagsgeschäft häufig frequentierten Aggregate für ältere und besonders für hochaltrige Menschen ein Hindernis ihrer eigenständigen Alltagsbewältigung darstellt. In Verbindung mit anderen, nichtzeitlichen Barrieren besteht für die älteren und hochaltrigen Menschen hierdurch das Risiko der Exklusion aus der Kern-Alltagswelt der sogenannten Leistungsträger der Gesellschaft und infolgedessen der Rückzug in eine eigene, nach anderen zeitlichen Regeln funktionierende, somit randständige Alltagswelt. Obwohl dieser Vorgang als solcher grundsätzlich als ambivalent zu werten ist, insofern dass er auch eine Schutzfunktion besonders für hochaltrige Menschen beinhalten kann, werden seine Auswirkungen per Saldo in dem vorliegenden Beitrag jedoch als stigmatisierend und damit als Problem für den gesellschaftlichen Zusammenhalt und als nicht dem Kriterium der Zeitgerechtigkeit entsprechend behandelt. Dies soll näher analysiert werden und Belastungen durch Zeitstrukturen - besonders durch zu hohe Geschwindigkeiten - sollen deutlicher erkannt werden. Dazu dient das Instrument der "Zeitverträglichkeitsprüfung", das kurz dargestellt wird. Als mittelfristig umsetzbare zeitpolitische Gestaltungsoption wird die Installation sogenannter Comfort-Buttons im Bereich der Alltagsaggregate des öffentlichen Raumes vorgeschlagen; sie sollen eine stärker an den zeitlichen Fähigkeiten und Bedürfnissen des Individuums orientierte Aggregatgeschwindigkeit ermöglichen und das Individuum in die Lage versetzen, zumindest selektiv die zeitliche Kontrolle über sein Alltagshandeln zurückzugewinnen.The aging of the population raises questions about the suitability of urban public spaces for meeting the needs of this growing group, not only in terms of built fabric and transport facilities but also in terms of the temporal structures found there. The paper posits that in the course of general societal acceleration a large proportion of elements frequently encountered in everyday life - such as overly fast escalators and pedestrian lights with very short crossing times - are a serious hindrance especially for older and very old people wishing to cope with their everyday lives autonomously. Even simple everyday actions, such as crossing a road, and the time required to accomplish them represent a considerable individual achievement that society usually either fails to acknowledge or underestimates. Combined with other non-temporal barriers this can lead to the exclusion of older, particularly very old, people from the core everyday world of the so-called key performers in society - that is, those who are in full possession of their capabilities and are "in the prime of life". The old and very old population may then retreat to their own everyday world that functions according to different temporal rules but that is viewed by the majority of society as marginalised. Such stigmatisation contradicts the criterion of temporal justice

Krise der Zeiterfahrung und industrielle Zeitwirtschaft

Wir knüpfen im folgenden an eine Diskussion an, die in den frühen 70er Jahren mit der Einführung von Gleitzeit-Systemen begann und die u.a. von B. Teriet unter dem Schlagwort »Zeitsouveränität« weitergeführt und mit der Forderung nach einer umfassenden Veränderung gesellschaftlicher Zeitstrukturen und individueller Zeitverwendung verbunden worden ist (vgl. Teriet 1977). Mit dieser Idee, die schon in den 60erJahren in Frankreich propagiert wurde (vgl. Chalendar 1972), verbindet sich vor allem auch die Vorstellung der Befreiung der Menschen in den hochindustrialisierten Ländern vom Diktat fremdbestimmter Zeitstrukturen. Individuelle zeitliche Optionen in und außerhalb der Arbeit sollen vergrößert werden. Großen Anklang finden solche Ansätze z.B. in Kreisen der Alternativbewegung, stellt doch die Selbstbestimmung über die eigene Zeit eine wichtige Voraussetzung für die Aufteilung zwischen erwerbswirtschaftlicher Arbeit und sogenannter Eigenarbeit dar. Aber auch aus arbeitsmarktpolitischer und -theoretischer Perspektive betrachtet sind neuartige Arbeitszeitstrukturen von erheblicher Relevanz, denn da eine freie Bestimmung über Dauer und Lage der Arbeitszeit zumeist zu verkürzten Arbeitszeiten führt, könnten durch die hieraus resultierende Verknappung des verfügbaren Arbeitsvolumens mehr Arbeitssuchende als bisher einen Arbeitsplatz finden

Synthesis and structure-activity relationship of piperidine-derived non-urea soluble epoxide hydrolase inhibitors

A series of potent amide non-urea inhibitors of soluble epoxide hydrolase (sEH) is disclosed. The inhibition of soluble epoxide hydrolase leads to elevated levels of epoxyeicosatrienoic acids (EETs), and thus inhibitors of sEH represent one of a novel approach to the development of vasodilatory and anti-inflammatory drugs. Structure-activities studies guided optimization of a lead compound, identified through high-throughput screening, gave rise to sub-nanomolar inhibitors of human sEH with stability in human liver microsomal assay suitable for preclinical development. © 2012 Elsevier Ltd. All rights reserved

Neutral tritium gas reduction in the KATRIN differential pumping sections

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the effective electron anti-neutrino mass with an unprecedented sensitivity of $0.2\,\mathrm{eV}/\mathrm{c}^2$, using $\beta$-electrons from tritium decay. The electrons are guided magnetically by a system of superconducting magnets through a vacuum beamline from the windowless gaseous tritium source through differential and cryogenic pumping sections to a high resolution spectrometer and a segmented silicon pin detector. At the same time tritium gas has to be prevented from entering the spectrometer. Therefore, the pumping sections have to reduce the tritium flow by more than 14 orders of magnitude. This paper describes the measurement of the reduction factor of the differential pumping section performed with high purity tritium gas during the first measurement campaigns of the KATRIN experiment. The reduction factor results are compared with previously performed simulations, as well as the stringent requirements of the KATRIN experiment.Comment: 19 pages, 4 figures, submitted to Vacuu

Suppression of Penning discharges between the KATRIN spectrometers

The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the effective electron (anti)-neutrino mass with a sensitivity of 0.2eV/c$^{2}$ by precisely measuring the endpoint region of the tritium β-decay spectrum. It uses a tandem of electrostatic spectrometers working as magnetic adiabatic collimation combined with an electrostatic (MAC-E) filters. In the space between the pre-spectrometer and the main spectrometer, creating a Penning trap is unavoidable when the superconducting magnet between the two spectrometers, biased at their respective nominal potentials, is energized. The electrons accumulated in this trap can lead to discharges, which create additional background electrons and endanger the spectrometer and detector section downstream. To counteract this problem, “electron catchers” were installed in the beamline inside the magnet bore between the two spectrometers. These catchers can be moved across the magnetic-flux tube and intercept on a sub-ms time scale the stored electrons along their magnetron motion paths. In this paper, we report on the design and the successful commissioning of the electron catchers and present results on their efficiency in reducing the experimental background

The design, construction, and commissioning of the KATRIN experiment

The KArlsruhe TRItium Neutrino (KATRIN) experiment, which aims to make a direct and model-independent determination of the absolute neutrino mass scale, is a complex experiment with many components. More than 15 years ago, we published a technical design report (TDR) [1] to describe the hardware design and requirements to achieve our sensitivity goal of 0.2 eV at 90% C.L. on the neutrino mass. Since then there has been considerable progress, culminating in the publication of first neutrino mass results with the entire beamline operating [2]. In this paper, we document the current state of all completed beamline components (as of the first neutrino mass measurement campaign), demonstrate our ability to reliably and stably control them over long times, and present details on their respective commissioning campaigns

Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN

We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of $(−1.0^{+0.9}_{−1.1}) eV^2$. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a factor of 2 and provides model-independent input to cosmological studies of structure formation