Festigkeitsänderungen bei verschiedenen Verformungsarten

Bestimmung von Streckgrenze und Zugfestigkeit beim Ziehen und Walzen von Stahldrähten mit Kohlenstoffgehalten zwischen 0,006 und 0,6%. Einfluß des Wechsels der Verformungsart vom Ziehen zum Walzen auf den weiteren Anstieg der Festigkeitswerte. Anfänglicher Abfall der Festigkeitswerte vor allem bei patentierten Stahldrähten mit höherem Kohlenstoffgehalt. Deutung des Festigkeitsabfalles als Zerstörung der bei der Verformung aufgetretenen Alterung und Änderung der gerichteten Eigenspannungen zwischen den verschiedenen Phasen.     

Comments on "Compression of the ECG by Prediction or Interpolation and Entropy Encoding"

A recent paper1 discusses prediction and interpolation for data compression of ECG. This communication points out that both methods can be viewed as linear filtering. They are therefore equivalent and give the same result in terms of the amount of data compression achieved.     

Praxisorientierte Raffination von Stahlschmelzen mit Seltenerdmetallen

Simulation eines pfannenmetallurgischen Stahlraffinationsverfahrens unter Verwendung von Cer-Mischmetall, einer Raffinationsschlacke und Argonspülung zur Reinheitsgradverbesserung. Darstellung typischer nichtmetallischer Einschlüsse. Aufzeigen der erzielten Zähigkeitsverbesserungen und der Verringerung der Zähigkeitsanisotropie.     

Ermittlung von gelöstem Kohlenstoff und Stickstoff mit einem Torsionspendel für streifenförmige Proben

Beschreibung eines Torsionspendels zur Messung der Dämpfung und Ermittlung des Gehaltes an gelöstem Kohlenstoff und Stickstoff an streifenförmigen Proben mit niedrigen Gehalten an interstitiell gelösten Elementen. Messung der Dämpfung bei Eisen-Kohlenstoff-, Eisen-Stickstoff- und Eisen-Kohlenstoff-Stickstoff-Legierungen ohne und mit Mangan. Darstellung der rechnerischen Ermittlung von Kohlenstoff und Stickstoff bei gleichzeitigem Vorliegen beider Elemente.     

Einfluß von Werkstoffzusammensetzung und Ferritkorngröße auf die Konstanten der Ludwik-Gleichung

Beschreibung der Spannung-Dehnung-Kurve ferritischer und ferritisch-perlitischer Stähle mit der Ludwik-Gleichung. Einfluß der Korngröße auf den Vorfaktor der Ludwik-Gleichung. Anstieg des Vorfaktors mit zunehmendem C- und Mn-Gehalt sowie mit steigendem Perlitanteil am Gefüge. Korngrößenunabhängigkeit des Verfestigungsexponenten. Einfluß des C- und Mn-Gehaltes auf den Verfestigungsexponenten.     

The partitioning of refactory metal elements in hafnium-modified cast nickel- base superalloys

Data from the electron microprobe have been used to elucidate the role of hafnium in altering the microstructure of the nickel-base superalloys B-1900, Alloy 713 LC, Udimet 700, and Mar-M246. The addition of about 1.3 to 2.0 pct Hf to these alloys improves their strength and ductility at both room temperature and 760°C. The data indicate that hafnium partitions to the surface of the MC carbides, replacing titanium and some molybdenum and/or tungsten in the carbide. On the basis of the observed morphology and composition of the carbides, it is postulated that, primarily, hafnium modifies the solidification sequence, which a) results in the formation of discrete, uniformly distributed MC carbides, b) retards the formation of secondary carbides, and c) contributes indirectly to solid solution strengthening of the matrix. Subsidiary of American Metal Climax, Inc. AMAX Division.     

A method for calibrated maximum likelihood classification of forest types

A modification to the maximum likelihood algorithm was developed for classification of forest types in Sweden's part of the CORINE land cover mapping project. The new method, called the “calibrated maximum likelihood classification” involves an automated and iterative adjustment of prior weights until class frequency in the output corresponds to class frequency as calculated from objective (field-inventoried) estimates. This modification compensates for the maximum likelihood algorithm's tendency to over-represent dominant classes and under-represent less frequent ones. National forest inventory plot data measured from a five-year period are used to estimate relative frequency of class occurrence and to derive spectral signatures for each forest class. The classification method was implemented operationally within an automated production system which allowed rapid production of a country-wide forest type map from Landsat TM/ETM+ satellite data. The production system automated the retrieval and updating of forest inventory plots, a plot-to-image matching routine, illumination and haze correction of satellite imagery, and classification into forest classes using the calibrated maximum likelihood classification. This paper describes the details of the method and demonstrates the result of using an iterative adjustment of prior weights versus unadjusted prior weights. It shows that the calibrated maximum likelihood algorithm adjusts for the overclassification of classes that are well represented in the training data as well as for other classes, resulting in an output where class proportions are close to those as expected based on forest inventory data.     

Improvements of fill factor in solar cells based on blends of polyfluorene copolymers as electron donors

The photovoltaic characteristics of solar cells based on alternating polyfluorene copolymers, poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)) (APFO-3), and poly(2,7-(9,9-didodecyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)) (APFO-4), blended with an electron acceptor fullerene molecule [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM), have been investigated and compared. The two copolymers have the same aromatic backbone structure but differ by the length of their alkyl side chain. The overall photovoltaic performance of the solar cells is comparable irrespective of the copolymer used in the active layer. However, the fill factor (FF) values of the devices are strongly affected by the copolymer type. Higher FF values were realized in solar cells with APFO-4 (with longer alkyl side chain)/PCBM bulk heterojunction active layer. On the other hand, devices with blends of APFO-3/APFO-4/PCBM were found to render fill factor values that are intermediate between the values obtained in solar cells with APFO-3/PCBM and APFO-4/PCBM active film. Upon using APFO-3/APFO-4 blends as electron donors, the cell efficiency can be enhanced by about 16% as compared to cells with either APFO-3 or APFO-4. The transport of holes in each polymer obeys the model of hopping transport in disordered media. However, the degree of energetic barrier against hopping was found to be larger in APFO-3. The tuning of the photovoltaic parameters will be discussed based on studies of hole transport in the pure polymer films, and morphology of blend layers. The effect of bipolar transport in PCBM will also be discussed.     

EXPERIMENTS WITH ONLINE REINFORCEMENT LEARNING IN REAL-TIME STRATEGY GAMES

Real-time strategy (RTS) games provide a challenging platform to implement online reinforcement learning (RL) techniques in a real application. Computer, as one game player, monitors opponents’ (human or other computers) strategies and then updates its own policy using RL methods. In this article, we first examine the suitability of applying the online RL in various computer games. Reinforcement learning application depends on both RL complexity and the game features. We then propose a multi-layer framework for implementing online RL in an RTS game. The framework significantly reduces RL computational complexity by decomposing the state space in a hierarchical manner. We implement an RTS game—Tank General—and perform a thorough test on the proposed framework. We consider three typical profiles of RTS game players and compare two basic RL techniques applied in the game. The results show the effectiveness of our proposed framework and shed light on relevant issues in using online RL in RTS games.