69 research outputs found
Theoretical study of pattern formation during the catalytic oxidation of CO on Pt{100} at low pressures
Get PDFTheoretical studies have thus far been unable to model pattern formation during the reaction in this system on physically feasible length and time scales. In this paper, we derive a computational reaction-diffusion model for this system in which most of the input parameters have been determined experimentally. We model the surface on a mesoscopic scale intermediate between the microscopic size of CO islands and the macroscopic length scale of pattern formation. In agreement with experimental investigations [M. Eiswirth et al., Z. Phys. Chem., Neue Folge144, 59 (1985)], the results from our model divide the CO and O2 partial pressure parameter space into three regions defined by the level of CO coverage or the presence of sustained oscillations. We see CO fronts moving into oxygen-covered regions, with the 1×1 to hex phase change occurring at the leading edge. There are also traveling waves consisting of successive oxygen and CO fronts that move into areas of relatively high CO coverage, and in this case, the phase change is more gradual and of lower amplitude. The propagation speed of these reaction waves is similar to those observed experimentally for CO and oxygen fronts [H. H. Rotermund et al., J. Chem. Phys.91, 4942 (1989); H. H. Rotermund et al., Nature (London)343, 355 (1990); J. Lauterbach and H. H. Rotermund, Surf. Sci.311, 231 (1994)]. In the two-dimensional version of our model, the traveling waves take the form of target patterns emitted from surface inhomogeneitie
Surfaces
No full textColloque organisé par Guy Ourisson du 10 au 16 juillet 2003 Participants Claude Amra, Serge Berthier, Henri Broch, Centi Gabriele, Christophe Coperet, Carole Deumié, Catherine Flecniakoska, Jean-Louis Flecniakoska, Frédérique Girard, Malcom Green, Jane H. Larsen, Marc Ledoux, Bernard Mourrain, Stéphane Mroczkowski, Guy Ourisson, David Quéré, Harm Heinrich Rotermund Compte-rendu Le Symposium « Surfaces »1 avait un objectif ambitieux : tenter d’intéresser pendant plusieurs jours un groupe très ..
Extraction of information from the dynamical activities of neural networks
No full textInteracting with our environment requires to process huge amounts of sensory data in short time. This incoming information is combined with internal states and results in actions. The fundamental mechanisms behind this information processing are still not understood. Even how information is stored in and transmitted with sequences of action potentials is still under heavy debate. This thesis presents three new contributions: A theoretical method of processing information spike by spike in a fast and efficient fashion. It was shown that it is sufficient to use Poissonian neurons for performing fast and efficient information processing. A new mechanism, produced through selective visual attention, was revealed that renders information about different visual stimuli, represented in the activity of neuronal populations, more distinct. A method for neuronal-prostheses capable of protecting estimators of intended actions against non-stationaries, for the cost of an extra error signal
Informationsextraktion aus der dynamischen Aktivität neuronaler Netzwerke
No full textInteracting with our environment requires to process huge amounts of sensory data in short time. This incoming information is combined with internal states and results in actions. The fundamental mechanisms behind this information processing are still not understood. Even how information is stored in and transmitted with sequences of action potentials is still under heavy debate. This thesis presents three new contributions: A theoretical method of processing information spike by spike in a fast and efficient fashion. It was shown that it is sufficient to use Poissonian neurons for performing fast and efficient information processing. A new mechanism, produced through selective visual attention, was revealed that renders information about different visual stimuli, represented in the activity of neuronal populations, more distinct. A method for neuronal-prostheses capable of protecting estimators of intended actions against non-stationaries, for the cost of an extra error signal
The Fog of Peace: Finding the End-State of Hostilities.
Get PDFThe author provides us with a new way of thinking about peace and how to achieve it. Peace, he argues, arrives only when domestically centered progress is established in a post-conflict environment. The end of hostilities is only the end of the shooting. It is not the end of danger. It is not the end of the animosities or typically the conditions leading to the hostilities. As a result, the end of hostilities represents the beginning of a transition to peace—not peace itself.https://press.armywarcollege.edu/monographs/1146/thumbnail.jp
The Interpretation of the Supreme People’s Court on the Application of the Administrative Procedure Law of the People’s Republic of China as of February 8, 2018
No full textIm Mai 2015 trat das revidierte Verwaltungsprozessgesetz der Volksrepublik China in Kraft, das mehr als zwei Jahrzehnte unverändert geblieben war. Fast zeitgleich verabschiedete das Oberste Volksgericht ebenfalls in 2015 seine Ansichten zur Anwendung des Verwaltungsprozessgesetzes der Volksrepublik China. Da das Verwaltungsprozessgesetz dennoch weiterhin nicht einheitlich angewandt wurde, schien eine umfassende neue Auslegung notwendig. In der neuen Auslegung des Obersten Volksgerichts zu einigen Fragen der Anwendung des Verwaltungsprozessgesetzes wird das revidierte Verwaltungsprozessgesetz noch umfassender interpretiert. Die Autorin untersucht den politischen Kontext der Erarbeitung dieser Auslegung von 2018, kommentiert diese ausführlich und vergleicht sie mit den vorherigen Bestimmungen. Das Ziel des Beitrags ist es aufzuzeigen, dass und auf welche Weise die Auslegung von 2018 die einheitliche Anwendung des Verwaltungsprozessgesetzes fördert, gleichzeitig aber auch, dass weiterhin Probleme bestehen.In May 2015, the amended Administrative Procedure Law of the People’s Republic of China came into force, replacing the previous Law which had not been revised for two decades. Almost at the same time in 2015, the Supreme People’s Court published its Interpretation on the Application of the Administrative Procedure Law of the People’s Republic of China. As the application of the law during the following years was nevertheless far from consistent, a new comprehensive interpretation seemed to be necessary and was promulgated in 2018. The author examines the political context of the new Interpretation, commenting on it in detail and also comparing the new rules to the former rules. The aim of the article is to show in which ways the new Interpretation fosters a consistent application of the Administrative Procedure Law. At the same time, the author highlights remaining problems
Digital media culture and public service media in the platform era
No full textThis chapter argues that a complete transformation to mature public service media institutions and strategies is necessary due to disruptive changes in global media structures producing a digital media culture (DMC). Broadcast enterprises are endangered by a generation rift and threatened with declining relevance and a minor role in online competition. Renewing their relevance requires abandoning the historic prioritisation of linearity and embracing interactivity in non-linear media production and operations. Building digital infrastructures for the production and distribution of linear programmes was accomplished and important, but can now be seen as an intermediary step in the continuing development of digital media culture. The future of public service media hinges on whether these organisations can be a proactive player in the digital media eco-system where the former privileges of heritage broadcasters will be dismantled or shared with other players. The author believes efforts in achieving this are uneven and, so far, too often ineffective
Digital media culture and public service media in the platform era
No full textThis chapter argues that a complete transformation to mature public service media institutions and strategies is necessary due to disruptive changes in global media structures producing a digital media culture (DMC). Broadcast enterprises are endangered by a generation rift and threatened with declining relevance and a minor role in online competition. Renewing their relevance requires abandoning the historic prioritisation of linearity and embracing interactivity in non-linear media production and operations. Building digital infrastructures for the production and distribution of linear programmes was accomplished and important, but can now be seen as an intermediary step in the continuing development of digital media culture. The future of public service media hinges on whether these organisations can be a proactive player in the digital media eco-system where the former privileges of heritage broadcasters will be dismantled or shared with other players. The author believes efforts in achieving this are uneven and, so far, too often ineffective
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