Parameterized High Throughput Function Evaluation for FPGAs

This paper presents parameterized module-generators for pipelined function evaluation using lookup tables, adders, shifters, multipliers, and dividers. We discuss trade-offs involved between (1) full-lookup tables, (2) bipartite (lookup-add) units, (3) lookup-multiply units, (4) shift-and-add based CORDIC units, and (5) rational approximation. Our treatment mainly focuses on explaining method (3), and briefly covers the background of the other methods. For lookup-multiply units, we provide equations for estimating approximation errors and rounding errors which are used to parameterize the hardware units. The resources and performance of the resulting design can be estimated given the input parameters. A selection of the compared methods are implemented as part of the current PAM-Blox module generation environment. An example shows that the lookup-multiply unit produces competitive designs with data widths up to 20 bits when compared with shift-and-add based CORDIC units. Additionally, the lookup-multiply method or rational approximation can produce efficient designs for larger data widths when evaluating functions not supported by CORDIC.     

Analytical and experimental investigations of the vibrations of a hollow blade model of turbines

The practice of using air-cooled blades for the increased efficiency of turbine stage is a recent feature with advanced aero-engines. The objective of the present paper is to describe the results of numerical and experimental investigation of the dynamical behaviour of hollow cross-sectioned blades. The analytical method consists in modelling the blades by means of a finite-element method to determine the natural frequencies and normal modes of a hollow cross-sectioned blade model. Numerical results are compared with experimental values obtained from holographic tests.     

Investigation of direct cooling in drawing steel wire

Experimental set-up of direct cooling in drawing steel wire. Calculation of the obtainable temperature drop in cooling tubes. Cooling rates measured at different operation parameters. Evaluation of friction coefficient. Thickness measurement of lubricant layers. Examination of mechanical properties of drawn wire.     

The ring compression test as simulation test for the investigation of friction in hot metal forming

Forces and flow of material in metal working decisively depend on friction between workpiece and tool, which can be described by the friction factor m. For investigation of the influence of friction in hot forming of steel and for measurement of the friction factor, the ring compression test is used as simulation test. The influences of material, reduction, strain rate, temperature, and lubricant are discussed.     

Richtspaltform und Bewegungsverhältnisse beim Richten von Rundstäben in Zwei-Walzen-Richtmaschinen

Besonderheiten des Zwei-Walzen-Richtens. Geometrie des Richtspalts: Schnitt der Biegeebene der Stabachse mit der hyperbolischen und der zylindrischen Walze, Berührungslinien zwischen Stab und Walzen, Biegelinie der Stabachse und größtmögliche Stabdurchbiegung. Kinematik des Richtvorgangs: Umfangsgeschwindigkeiten der hyperbolischen und der zylindrischen Walze, Vorschub- und Umfangsgeschwindigkeit des Stabes bei freier Biegung des Stabes und bei Biegung mit Querprägen, Schlupf. Anzahl der Biegungen eines Stabelementes und der Überrollungen eines Oberflächenelementes beim Durchlaufen der Maschine.     

The use of bismuth-backings for in-beam gamma spectroscopy

A method to prepare rolled bismuth foils is described and their advantages as target backings for in-beam γ-ray spectroscopy at beam energies below the Coulomb threshold of bismuth are discussed.     

Novel sulfur-containing telechelics with alternating aliphatic-aromatic structure units

Summary Radical polyaddition of 1,3-dimercaptobenzene onto 1,5-hexadiyne yields sulfur containing polyenolthioethers. By using the method of unstoichiometric ratio not only the molar masses but also the functional end groups of the products can be controlled. The telechelics synthesized are soluble in common solvents such as benzene, toluene and chloroform.We wish to thank the DFG (Nu 23/10) for financial support.     

Messung der anisothermischen statischen Entfestigung eines mikrolegierten Stahls nach der Warmumformung

Beschreibung eines Auswerteverfahrens für die statische Entfestigung unter anisothermischen Bedingungen von mit Niob mikrolegiertem Baustahl. Umformung mit dem Flachstauchversuch. Doppelschlagtechnik. Variation von Abkühlgeschwindigkeit Umformtemperatur und Umformgrad. Erstellung eines anisothermischen Zeit-Temperatur-Entfestigungs-Schaubildes.