No abstract

No abstract

Failure of a design to satisfy a system's requirements can result in schedule and cost overruns. When using current approaches, ensuring requirements are satisfied is often delayed until late in the development process during a cycle of testing and debugging. This paper introduces a more rigorous approach to design using Behavior Engineering, which has previously been applied primarily to requirements analysis and specification development. To support design with Behavior Engineering we introduce the embedded Behavior Runtime Environment, a virtual machine created to execute a Behavior Engineering design on an embedded system. The result is a model-driven development approach that can create embedded system software that satisfies its requirements, as a result of applying the development process.

A determination of the angular distributions, β, and relative partial photoionization cross sections, σ, of the valence satellite lines of atomic scandium in the region of the 3p → nd, ms excitations has been carried out using electron spectrometry in conjunction with monochromatized synchrotron radiation. This work is complementary to our earlier study of the partial cross sections of the Sc valence satellites but now includes angular distribution measurements of the most intense satellite lines. A correct theoretical description of the experimental satellite σ and β values presented herein should help in rectifying present discrepancies between theory and experiment for the 3d and 4s mainline σ and β values.

For the first time a time-resolved energy spectrum of a pseudospark-produced electron beam is constructed. A small portion of electron beam sampled at its axis is injected into a vacuum and the electrons passed through a negatively biased electrode are measured by a Faraday cup. The time-resolved energy spectrum is determined by analyzing the Faraday cup current waveforms measured at various bias voltages. The resultant spectrum reveals that the instantaneous 'beam energy is nearly monoenergetic. The energy is monotonically decreasing in time and resembles the anode-cathode voltage waveform. This suggests that electrons are accelerated by the full instantaneous anode-cathode voltage.