Search results for "metropolis"
showing 10 items of 43 documents
Anti-tempered Layered Adaptive Importance Sampling
2017
Monte Carlo (MC) methods are widely used for Bayesian inference in signal processing, machine learning and statistics. In this work, we introduce an adaptive importance sampler which mixes together the benefits of the Importance Sampling (IS) and Markov Chain Monte Carlo (MCMC) approaches. Different parallel MCMC chains provide the location parameters of the proposal probability density functions (pdfs) used in an IS method. The MCMC algorithms consider a tempered version of the posterior distribution as invariant density. We also provide an exhaustive theoretical support explaining why, in the presented technique, even an anti-tempering strategy (reducing the scaling of the posterior) can …
Gentrifizierung in periurbanen Räumen Frankreichs: Am Beispiel des Umlandes von Nancy
2019
International audience; Gentrifizierungsprozesse in periurbanen Räumen Frankreichs fanden in der Forschung bisher kaum Beachtung; sie wurden als naheliegende Prozesse in Kernstädten verstanden und untersucht. Zudem wurde eher die Krise der Vorstädte, der banlieues beachtet, womit Stigmatisierung und Ausgrenzung analyseleitend wurden. Im vorliegenden Beitrag wird nun hingegen am Beispiel des Umlandes der Metropole Nancy (Region Grand Est) Gentrifizierung als Entwicklung herausgestellt, die sich ebenfalls als konstitutiv für periurbane Räume und damit kleinere Umlandgemeinden von Städten bzw. insbesondere Metropolen andeutet. Vor dem Hintergrund einer Beleuchtung bisheriger Forschungszugänge …
Close packing of clusters: Application toAl100
2003
The lowest energy configurations of close-packed clusters up to N=110 atoms with stacking faults are studied using the Monte Carlo method with Metropolis algorithm. Two types of contact interactions, a pair-potential and a many-atom interaction, are used. Enhanced stability is shown for N=12, 26, 38, 50, 59, 61, 68, 75, 79, 86, 100 and 102, of which only the sizes 38, 75, 79, 86, and 102 are pure FCC clusters, the others having stacking faults. A connection between the model potential and density functional calculations is studied in the case of Al_100. The density functional calculations are consistent with the experimental fact that there exist epitaxially grown FCC clusters starting from…
Monte Carlo simulation of correlated electrons in disordered systems
1992
Abstract The properties of many-electron states in disordered systems with long-range electron-eletron interaction are investigated by means of a Monte Carlo simulation. Using the Metropolis algorithm, three-dimensional systems up to 512 sites are systematically analysed. The low-lying excitations are investigated in order to distinguish between one-particle and many-particle hopping. In the interesting regime in which disorder and correlation effects are equally important we find that variable-range hopping is insignificant for electron transfer when compared with the contribution from nearest-neighbour one-electron hopping processes as well as variable-number hopping.
Monte Carlo simulation of crystalline polyethylene
1996
Abstract We consider here the problem of constructing an efficient algorithm for a classical Monte Carlo simulation of crystalline polyethylene with unconstrained bond lengths and angles. This macromolecular crystal presents a particular example of a system with many different energy scales, ranging from soft ones represented by nonbonded van der Waals interactions, to stiff ones, represented in particular by bond stretching. A proper sampling of all the energy scales poses a problem and it is shown that a standard Metropolis algorithm employing just local moves is not very efficient at low temperatures. As a solution it is proposed to employ also global moves consisting of displacements of…
Rappresentare la Post-metropoli. La Sicilia Sud-Orientale oltre gli stereotipi massmediatici.
Recensione di I territori marginali e la quarta rivoluzione urbana. Il caso della Gallura
2019
La recensione commenta un volume che presenta i risultati di un'unità di ricerca loacale, quella dell'Università di Sassari-Alghero, nel quadro di una ricerca PRIN nazionale sul tema della Postmetropoli che ha visto come capofila il Politecnico di Milano. Il volume fa parte di una serie di altri volumi, curati da altre sedi locali, che nell'insieme restituiscono i risultati della ricerca. The review discusses on a book that presents the results of a loacal research unit,in the University of Sassari-Alghero, as part of a national PRIN research on the theme of the Postmetropolis, as Soja wrotes, with the Polytechnic of Milan as the leader. The volume is part of a series of volumes, edited by …
Kiborgs, kā filmai Metropolis raksturīgs elements japāņu filmu kultūrā
2015
Filma Metropolis ir viena no slavenākajām filmām pasaulē un ir priekšnācēja visām fantastikas žanra filmām. Šajā filmā tika attēloti koncepti par lietām, ko tā laika publika vēl nebija redzējusi – idejas par tik tehniski attīstītu sabiedrību, kur ir iespējama mākslīgās dzīvības radīšana. Roboti un neparasti cilvēku tēli – visām šīm lietām filma ir iedvesusi dzīvību. Darbā tiks pētīts aspekts, ko, manuprāt, filma Metropolis ir postulējusi – kiborgs, vai kā to sauc filmā: Der Maschinen-Mensch (mašīnas cilvēks). Šis aspekts tiks meklēts japāņu filmu kultūrā, konkrētāk – animē. Vēlāk šie filmas un animē elementi tiks salīdzināti un tiks meklētas kulturālās, vizuālās un kontekstuālās līdzības. I…
South-eastern Sicily: a counterfactual post-metropolis
2017
Postmetropolis is an ambitious term that could be summarized as the "postmodern metropolis." With it Edward W. Soja (2000) aims to define the globalized city that he supposes to be involved in a radical transition process that began with the post-modern city. In relation to these considerations, the article explores the post-metropolitan profile of South-eastern Sicily through: a socio-economic outlook describing the characteristics of demography, employment and income in this part of Sicily; a spatial analysis of housing and land use; and finally an institutional description of the administrative state of the art in Syracuse, Ragusa and their surroundings. Each section describes the most c…
Markov Chain Monte Carlo Methods for High Dimensional Inversion in Remote Sensing
2004
SummaryWe discuss the inversion of the gas profiles (ozone, NO3, NO2, aerosols and neutral density) in the upper atmosphere from the spectral occultation measurements. The data are produced by the ‘Global ozone monitoring of occultation of stars’ instrument on board the Envisat satellite that was launched in March 2002. The instrument measures the attenuation of light spectra at various horizontal paths from about 100 km down to 10–20 km. The new feature is that these data allow the inversion of the gas concentration height profiles. A short introduction is given to the present operational data management procedure with examples of the first real data inversion. Several solution options for…