Role of Perceived Importance in Intergroup Contact.

Furthering G. W. Allport's (1954) contentions for optimal contact, the authors introduce a new construct: the perceived importance of contact. They propose that perceived importance is the best proximal predictor of contact's reduction of prejudice. If individuals have opportunities for contact at work or in the neighborhood, their chances to have intergroup acquaintances and friends increase. Intergroup contact among acquaintances and friends can be perceived as more or less important, which in turn determines intergroup evaluations. A 1st study shows that the new measure of perceived importance is indeed distinct from established quantity and quality indicators. The results are cross-validated in a 2nd study that also sheds light on the meaning of importance. In 3rd and 4th studies, structural equation analyses and a meta-analysis support the hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimating the Optimal Margins of Embeddings in Euclidean Half Spaces

Concept classes can canonically be represented by matrices with entries 1 and –1. We use the singular value decomposition of this matrix to determine the optimal margins of embeddings of the concept classes of singletons and of half intervals in homogeneous Euclidean half spaces. For these concept classes the singular value decomposition can be used to construct optimal embeddings and also to prove the corresponding best possible upper bounds on the margin. We show that the optimal margin for embedding n singletons is and that the optimal margin for half intervals over {1,...,n} is . For the upper bounds on the margins we generalize a bound by Forster (2001). We also determine the optimal margin of some concept classes defined by circulant matrices up to a small constant factor, and we discuss the concept classes of monomials to point out limitations of our approach.     

Detecting zero-day attacks using context-aware anomaly detection at the application-layer

Anomaly detection allows for the identification of unknown and novel attacks in network traffic. However, current approaches for anomaly detection of network packet payloads are limited to the analysis of plain byte sequences. Experiments have shown that application-layer attacks become difficult to detect in the presence of attack obfuscation using payload customization. The ability to incorporate syntactic context into anomaly detection provides valuable information and increases detection accuracy. In this contribution, we address the issue of incorporating protocol context into payload-based anomaly detection. We present a new data representation, called \({c}_n\)-grams, that allows to integrate syntactic and sequential features of payloads in an unified feature space and provides the basis for context-aware detection of network intrusions. We conduct experiments on both text-based and binary application-layer protocols which demonstrate superior accuracy on the detection of various types of attacks over regular anomaly detection methods. Furthermore, we show how \({c}_n\)-grams can be used to interpret detected anomalies and thus, provide explainable decisions in practice.     

Bitterstoffe beim Erhitzen von Saccharose, Maltose und Prolin 2. Mitteilung

Summary In addition to the mono- and dipyrrolidinohexosereductones described recently (Z Lebensm Unters Forsch (1984) 178:356) two further bittertasting compounds were isolated from heated mixtures of proline and sucrose (molar ratio 3: 1, 190 °C, 30 min) and also synthesized, namely 2,3-bis-(1-pyrrolidinyl)2-cyclopenten-l-one and 2,3-bis(1-pyrrolidinyl)-5methyliden-2-cyclopenten-l-one. The recognition thresholds (mmol/1) are 0.15–0.25 and 0.06–0.12 respectively. Both compounds have a burning bitter taste character. From a maltose-proline reaction mixture 2--glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-one was isolated. When the dihydroxypyranone VI was heated with proline, 2,5-dihydroxy-5-methyl-4-prohnyl-2-cyclopenten-1-one and the cyclopent(b)azepinones XI and XII were among the compounds formed. These compounds also have a bitter taste character.Zusammenfassung Zusätzlich zu den kürzlich beschriebenen Mono- and Dipyrrolidinohexosereduktionen (Z Lebensm Unters Forsch (1984) 178:356) wurden zwei weitere bittere Verbindungen aus erhitzten Mischungen von Prolin and Saccharose (Molverhältnis 3:1, 190 °C, 30 min) isoliert and synthetisiert. Es handelt sich um 2,3-Bis-(1-Pyrrolidinyl)-2-cyclopenten-1-on und 2,3-Bis-(1-Pyrrolidinyl)-5-methyliden-2-cyclopenten-1-on. Die Erkennungsschwellenwerte (mmol/1) sind 0,15-0,25 and 0,06-0,12. Beide Verbindungen haben einen brennend-bitteren Geschmack. Aus einem Maltose-Prolin-Umsetzungsgemisch gelang die Isolierung des 2--Glucosyl-5-hydroxy-5-methyl-4-piperidinyl-2-cyclopenten-1-ons. Bei der Reaktion des Dihydropyranons VI mit Prolin wurden u. a. das 2,5-Dihydroxy-5-methyl-4-prolinyl2-cyclopenten-1-on sowie die Cyclopent(b)azepinone XI and XII gebildet. Diese Verbindungen sind ebenfalls mehr oder weniger stark bitter.     

STUDIES ON THE MYCOFLORA OF MALT

The mycoflora of malt which caused gushing beer has been investigated and compared with the mycoflora of malt from nine malting plants in Sweden, Denmark, Finland and England. Malt which caused gushing beer was found to contain a high proportion of grains contaminated by Aspergillus, Penicillium and Rhizopus. The commonest species isolated were found to be Aspergillus fumigatus and Aspergillus amstelodami. These fungi occurred on all malt samples investigated independent of their origin. The mycoflora on malt differs greatly from that found on barley. Evidence is presented showing that barley becomes contaminated during the malting process.     

Magnetic properties of non-oriented magnetic steel at medium frequencies

The magnetic properties of non-oriented magnetic steel are specified at a frequency of 50 or 60 Hz. The effect of increasing the frequency of the magnetizing field upon the specific total loss, the field strength and the specific apparent power is demonstrated. Regarding the non-oriented steel at 50 Hz total loss comprises mainly hysteresis loss, whereas the eddy-current loss of most of the grades amounts to less than 40%. The approximately square increase of the eddy-current loss with frequency means that at 400 Hz the total loss is determined by the resistivity. For excitations up to a peak polarization of 1.6 T increasing sheet thickness results in an increasing field strength at 400 Hz. While at 50 Hz low-alloyed grades have a lower field strength above 1.3 T, at 400 Hz the field strength of the high-alloyed grades is more favourable up to 1.4 T. With respect to the apparent power, the square of which is proportional to the copper losses, there is an advantage of the higher alloyed grades up to 1.5 T.     

Corrosion of high temprature alloys in the primary circuit helium of high temperature gas cooled reactors. – Part I: Theoretical background

The interaction of Ni and Fe-Ni base alloys with the reactive impurities H₂O, CO, H₂ and CH₄ in simulated cooling gas of the primary circuit of the High Temperature Gas Cooled Reactor (HTGR) causes corrosion effects that can significantly influence the mechanical properties. Apart from the formation of surface scales (oxides, carbides or mixed oxides/carbides), structural changes of the alloys are observed; depending on gas composition, gas supply rate and test temperature, carburization or decarburization can occur. In this report it is shown that an interpretation of the basic corrosion effects is possible on the basis of a modified stability diagram for chromium provided that - the kinetics of elementary gas metal reactions are incorporated in the expressions for carbon activity and oxygen partial pressure of the atmosphere and - the gradients of the potentials across the surface scales are taken into account. The interpretation allows the derivation of the corrosion behaviour of NiCr-base alloys in different HTGR helium compositions and enables the limits for the formation of protective chromia surface scales to be given. The influence of alloying elements other than chromium can be explained qualitatively. The results can be transferred to other reactive gas mixtures, which are characterized by an oxygen partial pressure near to the dissociation pressure of the scale forming oxides.     

Effect of hydrogen,restraint and welding conditions on weld metal cold cracking of HSLA steels in the IRC test

The effect of heat input and hydrogen partial pressure of the TIG process without filler wire and of restraining conditions in the IRC test on hydrogen induced cracking have been investigated for weld metals of StE 380, 15 NiCrMo 10 6 (HY 80) and 12 Ni 19. The weld metals are fused from the roots of the plate materials exclusively. The continuously measured combined nominal stresses transverse to the welds are strongly dependent on transformation stress release prior to cold cracking of the respective weld metals. Higher restraints are increasing nominal stresses. Critical heat inputs for prevention of hydrogen weld metal cracking are increased with restraint, hydrogen potentials and carbon contents of the weld metal, 12 Ni 19 revealing no fracture.     

SETL to ADA—tree transformations applied

This paper describes ongoing work at the Institute dealing with the translation of the prototyping language SETL into the production language ADA. Funded in part by ESPRIT, contract number 1227 (1271), a preliminary version was presented at WG '87—Graphictheoretic Concepts in Computer Science, July 1987, Kloster Banz, FRG. In order to place this work in the proper context in software engineering, a brief overview is given of the relatively recent methodology of prototyping using executable specifications. Then the very high level language SETL is characterized and the programming environment Mentor is briefly introduced. Program transformations are also discussed.

After discussing the reasons for selecting ADA as a target language, a translation of SETL's data will be discussed as well as control structures in ADA. The latter point will exemplify how this is done using the transformation of abstract syntax trees. Finally, a brief example of a SETL program and its translation into ADA will be given to convey the flavour of this translation.     

SCR operation mode of diode strings for ESD protection

Diodes and diode strings in 90 nm and beyond technologies are investigated by measurement and device simulation. After a thorough calibration, the device simulator is utilised to achieve a better understanding and an enhanced device performance of diode strings under static and transient ESD conditions. Thereto, parasitic transistors and a so far neglected parasitic thyristor (SCR) in the diode string are regarded, exploited and optimised.