47 research outputs found
On Fishman's sampling plan for computing network reliability
No full textinfo:eu-repo/semantics/publishe
Technologie de la conservation du sperme chez plusieurs vertébrés domestiques: protection des lipides membranaires, intégrité du noyau et élargissement des méthodes
No full textSeismic risk evaluation with PSHA methods in southeastern France and northwestern Italy
No full textLAUREA MAGISTRALEObiettivo del presente lavoro è la valutazione del rischio sismico nella zona sud-est della Francia e nord-ovest dell'Italia per mezzo di tre differenti metodi. La probabilità annuale di superamento di un dato livello di danno per diverse classi di edifici viene definita secondo la scala EMS-98. Il primo approccio considera la storicità sismica e le caratteristiche delle isosisme. Si calcolano inoltre le aree medie colpite e i relativi periodi di ritorno e sulla loro base si analizza la distribuzione log-normale del raggio medio delle isosisme e viene definita quindi una relazione locale di attenuazione. La seconda tecnica è basata sulla convoluzione di pericolosità sismica, come definita dal progetto Europeo SHARE, e delle curve di fragilità (derivate da approcci empirici, analitici e ibridi) ottenuti dal database SYNER-G. Le probabilità così ottenute hanno evidenziato una discrepanza di un fattore 100 con il primo metodo ma sono risultate coerenti tra loro. Infine, il codice SASHA, basato su un metodo site approach, ha fornito la intensità di riferimento con una probabilità di superamento del 10% in 50 anni. Non basandosi sulla zonazione sismica come il classico metodo di Cornell, questa tecnica si dimostra particolarmente adatta all'area di studio, dove questo tipo di informazione è scarsa. I risultati hanno definito un'intensità VI per circa il 55% della regione. Le intensità sono state convertite in PGA per essere comparate con la mappa SHARE. Sono state ottenute differenze massime di 0.1 g in 91% dell'area.Seismic risk is evaluated in the southeastern region of France and the northwestern sector of Italy according to three different methods. The annual probability of exceedance of a given damage for different building classes is evaluated according to the EMS-98 scale.
The first approach considers historical earthquakes and statistics of isoseismals. Furthermore, affected areas, return periods are also computed and on their basis a log-normal distribution of the average isoseismals radius as well as a local attenuation relationship are identified. The second technique is based on the convolution of seismic hazard defined by the European SHARE project and fragility curves (derived from empirical, analytical and hybrid approaches) downloaded from the SYNER-G database. The obtained probabilities outlined a discrepancy of a factor of 100 with respect to the first method but resulted coherent among them. Lastly, the code SASHA, based on a site approach PSHA method, has provided the reference intensity with a 10% probability of exceedance within 50 years. Because it is not based on the seismic zonation as the classic Cornell method, this technique is particularly suitable to the analysed area, where this type of information is scarce. Results defined an intensity VI for around 55% of the region. Intensities have been eventually converted to PGA in order to be compared with the SHARE map. Values in accordance of 0.1 g for 91% of the region have been obtained
The Superficial Anastomosing Veins of the Human Brain Cortex: A Microneurosurgical Anatomical Study
No full textIntroduction: In this microneurosurgical and anatomical study, we characterized the superficial anastomosing veins of the human brain cortex in human specimens. Material and Methods: We used 21 brain preparations fixed in formalin (5%) that showed no pathological changes and came from the autopsy sections. The superficial veins were dissected out of the arachnoid with the aid of a surgical microscope. Results: We dissected nine female and 12 male brain specimens, with an average age of 71 ± 11 years (range 51–88 years). We classified the superficial veins in five types: (I) the vein of Trolard as the dominat vein; (II) the vein of Labbé as the dominant vein; (III) a dominant sylvian vein group, and the veins of Trolard and Labbé nonexistent or only rudimentary present without contact to the Sylvian vein group; (IV) very weak sylvian veins with the veins of Trolard and Labbé codominant; and V) direct connection of Trolard and Labbé bypassing the Sylvian vein group. The vein of Trolard was dominant (Type I) in 21.4% and the vein of Labbé (Type II) in 16.7%. A dominant sylvian vein group (Type III) was found in 42.9%. Type IV and Type V were found in 14.3 and 4.7% respectively. Conclusion: No systematic description or numerical distribution of the superior anastomotic vein (V. Trolard) and inferior anastomotic vein (V. Labbé) has been found in the existing literature. This study aimed to fill this gap in current literature and provide data to neurosurgeons for the practical planning of surgical approaches
Data analytics for trajectory selection and preference-model extrapolation in the European airspace
No full textRepresenting airspace users’ preferences in Air Traffic Flow Management (ATFM) mathematical models is becoming of high relevance. ATFM models aim to reduce congestion (en-route and at both departure and destination airports) and maximize the Air Traffic Management (ATM) system efficiency by determining the best trajectory for each aircraft. In this framework, the a-priori selection of possible alternative trajectories for each flight plays a crucial role. In this work, we analyze initial trajectories queried from Eurocontrol DDR2 data source. Clustering trajectories yields groups that are homogeneous with respect to known (geometry of the trajectory, speed) and partially known or unknown factors (en-route charges, fuel consumption, weather, etc.). Associations between grouped trajectories and potential choice-determinants are successively explored and evaluated, and the predictive value of the determinants is finally validated. For a given origin-destination pair, this ultimately leads to determining a set of flight trajectories and information on related airspace users’ preferences
Exact Solution of the SONET Ring Loading Problem
No full textIn this paper we address the problem of planning the capacity of the local rings in Synchronous Optical NETworks (SONET). We present efficient lower and upper bound procedures and a branch and bound algorithm which is able to find the exact solution of large instances within short computing times
An Improved Arcflow Model for the Skiving Stock Problem
No full textBecause of the sharp development of (commercial) MILP software and hardware components, pseudo-polynomial formulations have been established as a viable tool for solving cutting and packing problems in recent years. Constituting a natural (but independent) counterpart of the well-known cutting stock problem, the one-dimensional skiving stock problem (SSP) asks for the maximal number of large objects (specified by some threshold length) that can be obtained by recomposing a given inventory of smaller items. In this paper, we introduce a new arcflow formulation for the SSP applying the idea of reflected arcs. In particular, this new model is shown to possess significantly fewer variables as well as a better numerical performance compared to the standard arcflow formulation
Uncovering the Missing Link between Molecular Electrochemistry and Electrocatalysis: Mechanism of the Reduction of Benzyl Chloride at Silver Cathodes
No full textCentre National de la Recherche Scientifique, the Universite Pierre et Marie Curie, the Ecole Normale Superieure (Unite Mixte de Recherche 8640); Centre National de la Recherche Scientifique, the Universite Pierre et Marie Curie, the Ecole Normale Superieure (Laboratoire International Associe XiamENS); Agence Nationale de la Recherche Chaire d'Excellence "MicroNanoChem" [ANR-10-CHEX-012-01]; National Science Foundation of China [21061120456]; Universite degli Studi di Milano (PUR Funds
