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Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A1. Longitudinally polarized positrons were scattered off a longitudinally polarized hydrogen target for values of Q2 between 1.2 and 12 GeV2 and values of W2 between 1 and 4 GeV2. The average double-spin(More)
The Unified Modeling Language UML is well-suited for the design of real-time systems. In particular, the design of dynamic system behaviors is supported by interaction diagrams and statecharts. Real-time aspects of behaviors can be described by time constraints. The semantics of the UML, however, is non-formal. In order to enable formal design verification,(More)
In addition to static structures, the Unified Modelling Language (UML) supports the specification of dynamic properties of objects by means of statechart and sequence diagrams. Moreover, the upcoming UML 2.0 standard defines several kinds of actions to specify invocations, computations and the access of structural features. The formal specification(More)
Many modern chemical plants have to be modelled as complex hybrid systems consisting of various continuous and event-discrete components. Besides of the modular and easy-to-read specification, the formal verification of required properties (e.g., safety properties) is a major problem due to the complexity of the models. In practice, mostly informal(More)
The HERMES experiment is collecting data on inclusive and semi-inclusive deep inelastic scattering of polarised positrons from polarised targets of H, D, and 3 He. These data give information on the spin structure of the nucleon. This paper describes the forward angle spectrometer built for this purpose. The spectrometer includes numerous tracking chambers(More)
In order to support formally correctness preserving reenement steps of object-oriented system designs, we refer at one hand to the practically well-accepted Uniied Modelling Language (UML) and at the other hand to L. Lamport's Temporal Logic of Actions (TLA) which supports concise and precise notions of properties of dynamic behaviours and corresponding(More)