3D particle tracking velocimetry using dynamic discrete tomography

Particle tracking velocimetry in 3D is becoming an increasingly important imaging tool in the study of fluid dynamics, combustion as well as plasmas. We introduce a dynamic discrete tomography algorithm for reconstructing particle trajectories from projections. The algorithm is efficient for data from two projection directions and exact in the sense that it finds a solution consistent with the experimental data. Non-uniqueness of solutions can be detected and solutions can be tracked individually

Taylor's (1935) dissipation surrogate reinterpreted

New results from direct numerical simulation of decaying isotropic turbulence show that Taylor’s expression for the viscous dissipation rate ε = CεU3/L is more appropriately interpreted as a surrogate for the inertial energy flux. As a consequence, the well known dependence of the Taylor prefactor Cε on Reynolds number Cε(RL)→Cε,∞ can be understood as corresponding to the onset of an inertial range

A comparison of genetic and greedy randomized algorithms for medium-to-short-term audit-staff scheduling

Based upon an empirical survey among the 200 biggest CPA firms in Germany an hierarchical modeling framework for audit-staff scheduling with three levels has been developed. For the second level, the so-called medium-to-short-term planning, a binary optimization model is introduced which is closely related to resource-constrained project scheduling. In an extensive computational study several genetic algorithms (GA) with and without domain-specific knowledge as well as a greedy randomized algorithm (RA) are investigated. Besides introducing a generalization concerning the representation of the genes of a GA which is applicable to a wide range of recent procedures it is proved that the RA is a special case of a GA. Furthermore, we observed that a GA of a modest population size with domain-specific knowledge performed best if at least a certain number of individuals is generated

Revidierende hierarchische Planung: Ein Konzept am Beispiel der Personaleinsatzplanung in Wirtschaftsprüfungsgesellschaften

Am Beispiel eines neuen, auf einer empirischen Erhebung basierenden Ansatzes zur Personaleinsatzplanung in Wirtschaftsprüfiingsgesellschaften wird die Bedeutung der Integration revidierender Planungskonzepte in Ansätze mit hierarchischer Struktur aufgezeigt. Neu nach einem Planungslauf hinzugekommene Informationen müssen zum einen derart in das System aufgenommen werden, daß Planänderungen auf ein für den Benutzer akzeptables Maß beschränkt bleiben. Zum anderen muß - insbesondere bei hierarchischen Ansätzen - die Konsistenz auf allen Modellebenen gewährleistet sein.With respect to a new approach to audit-staff scheduling the importance of concepts for re-scheduling in frameworks with hierarchical structure is discussed. It is proposed how to handle new informations which are received after preparing a schedule. First, the number of changes in the current schedule has to be limited to a ratio acceptable for the user; second, consistency within all levels of the hierarchical framework has to be guaranteed

Waveguide Bandpass Filters for Millimeter-Wave Radiometers

A fundamental requirement for most mm-wave heterodyne receivers is the rejection of the input image signal which is located close to the local oscillator frequency. For this purpose we use a bandpass filter, which for heterodyne receivers is also called an image rejection filter. In this paper we present a systematic approach to the design of a waveguide bandpass filter with a passband from 100 to 110 GHz and upper rejection bandwidth in the range from 113 to 145 GHz. We consider two non-tunable filter configurations: the first one is relatively selective with 11 sections (poles) whereas the second one is simpler with 5 sections. We used established design equations to propose an initial guess for the geometries of the filters, optimized the geometries, constructed the filters using two different milling methods, measured their transmission and reflection characteristics, and compared the measurements with numerical simulations. Measurements of both filters agree well with simulations in frequency response and rejection bandwidth. The insertion loss of the 11-pole filter is better than 10 dB and that of the 5-pole filter is better than 5 dB. The 11-pole filter has a sharper attenuation roll-off compared with the 5-pole filter. The upper out-of-band rejection is better than 40 dB up to 145 GHz for the 11-pole filter and up to 155 GHz for the 5-pole filter

Место инновационной рекламы в инновационном бизнесе

В наше время становится, очевидно, что стратегическим фактором развития почти для каждого предприятия и в целом экономики являются инновации, внедрение которых существенно влияют на процветание инновационного бизнеса и требуют продвижения продуктов с помощью инновационной рекламы.Nowadays it becomes obvious that a strategic development factor for almost every business and overall economy are innovation, the introduction of which significantly affect the prosperity of business innovation and demand promoting a product by using innovative advertising