A derives grid-based model for simulation of pedestrian flow

We present a derived grid-based model for the simulation of pedestrian flow. Interactions among pedestrians are considered as the result of forces within a certain neighbourhood. Unlike the social force model, the forces here, as in Newtonian physics, are proportional to the inverse of the square of the distance. Despite the notion of neighbourhood and the underlying grid, this model differs from the existing cellular automaton (CA) models in that the pedestrians are treated as individuals. Bresenham's algorithm for line rastering is applied in the step calculation.     

Wer geht auf die Hauptschule? Primäre und sekundäre Effekte der sozialen Herkunft beim Übergang nach der Grundschule

It can be especially controversial when pupils are transferred to the “Hauptschule”, which is the lowest of three tracks in the German secondary school system. The acceptance of this type of school is very low for both parents and pupils. By contrast with the transfers of pupils to the high ability grammar school (“Gymnasium”), there are no recent studies on transfers to the “Hauptschule”. Analyses using data from the Bavarian partial sample in the KOALA-S study show that the discrepancy between the aspirations of parents and pupils on the one hand and the school type recommended by teachers and the pupil registrations on the other hand is particularly large when pupils are transferred to the “Hauptschule”. Discrepancies concerning transfers to the “Realschule” (intermediate track; commercial/technical secondary school) or “Gymnasium” are less severe. Unwanted attendance at the “Hauptschule” most frequently affects children from families with lower social or educational status. Analyses with an elaborated simulation procedure (counterfactual calculations) show that attendance at the “Hauptschule” mainly results from poor school achievements, whereas social selectivity due to parents decision making or transition regulations is far less important.     

Climatically Induced Degradation Processes in Conserved Archaeological Wood Studied by Time-lapse Photography

ABSTRACT

Samples of conserved archaeological wood of different ages, origins, and conservation histories were aged in a climate chamber for seven months, while the humidity alternated between 30% RH for 12 hours and 80% RH for 12 hours at a constant temperature of 30°C. Photographs were taken once every hour, which enabled the creation of a time-lapse movie. Some samples degraded visibly, whereas others were unaffected. Most of the samples were robust and would be able to survive well even in a very poor museum climate. Among the sensitive samples, three types of degradation were identified, namely disintegration, pyrite oxidation, and efflorescence of white crystals. Disintegration was ascribed to dimensional changes caused by the RH alternations in very fragile wood. The white efflorescence was interpreted as the recrystallization of an alum-associated substance, possibly mercallite (KHSO₄). The pyrite oxidation was observed as the efflorescence of a thick yellow, grey, and green powder. Characterization of selected samples was performed using X-ray fluorescence spectrometry, X-ray diffraction spectrometry, scanning electron microscopy with energy dispersive X-ray spectroscopy, inductively coupled plasma – optical emission spectroscopy, Fourier transform infrared spectroscopy, ionic conductivity – liquid chromatography, and pyrolysis-gas chromatography-mass spectrometry with in situ silylation using hexamethyldisilazane.     

The lure of internationalization: paradoxical discourses of transnational student mobility,linguistic diversity and cross-cultural exchange

This paper scrutinizes a set of paradoxes arising from a mismatch between contemporary discourses that praise and promote mobility in and internationalization of higher education, and the everyday effects of mobility and internationalization on university teaching and learning practice. We begin with a general characterization of the discourse of mobility and internationalization in a European context and then turn to Denmark as a specific case in which we unfold and discuss three paradoxes in turn: internationalization and linguistic pluralism, internationalization and intercultural understanding and, finally, internationalization and competitiveness. We then link our deconstruction of the three paradoxes to a critique of the concept of “parallel language policy,” widely promoted in the Nordic context, and show how it potentially undermines the ideals of internationalization.     

2. German-Language Studies

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Melissa Milar and William Brohaugh, eds. 1978 Photographer's Market (Cincinatti, Ohio: Writer's Digest, 1977—$9.95)

John S. Carroll's Photographic Lab Handbook (Garden City, N.Y.: Amphoto, 1977—$10.95, paper)

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Dennis Longwell's Steichen: The Master Prints, 1895-1914: The Symbolist Period (New York: Museum of Modern Art/Boston: New York Graphic Society, 1978—$35.00)

Neal Slavin's When Two or More are Gathered Together (New York: Farrar, Straus, Giroux, 1976—$12.95, paper)

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Kent E. Wade, Alternative Photographic Processes (Dobbs Ferry, N.Y.: Morgan &; Morgan, 1978—$11.95, paper)

The Nikon Manual, Incorporating the Nikkormat and Nikonos (Dobbs Ferry, N.Y.: Morgan &; Morgan, 1977—$24.95)