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Search Results: 1 - 10 of 335270 matches for " P. E.;Villani "
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Petri Net approach for modelling system integration in intelligent buildings
Miyagi, P. E.;Villani, E.;Gustin, G. D. B.;Maruyama, N.;Santos Filho, D. J.;
Journal of the Brazilian Society of Mechanical Sciences , 2002, DOI: 10.1590/S0100-73862002000400015
Abstract: in this paper, a petri net approach is introduced for modelling and simulation of control strategies in intelligent building. in this context, it is claimed that integration with other building systems can be achieved in a more systematic way considering a mechatronic approach (i.e. multidisciplinary concepts applied to the development of systems). the case study is the ambulatory building of medical school hospital of university of s?o paulo. particularly, the developed methodology is applied to the elevator system and to the hvac (heating, ventilation and air conditioning) system. it is shown that using this approach, the control systems could be integrated, improving performance.
Petri Net approach for modelling system integration in intelligent buildings
Miyagi P. E.,Villani E.,Gustin G. D. B.,Maruyama N.
Journal of the Brazilian Society of Mechanical Sciences , 2002,
Abstract: In this paper, a Petri Net approach is introduced for modelling and simulation of control strategies in Intelligent Building. In this context, it is claimed that integration with other building systems can be achieved in a more systematic way considering a mechatronic approach (i.e. multidisciplinary concepts applied to the development of systems). The case study is the Ambulatory Building of Medical School Hospital of University of S o Paulo. Particularly, the developed methodology is applied to the elevator system and to the HVAC (Heating, Ventilation and Air Conditioning) system. It is shown that using this approach, the control systems could be integrated, improving performance.
Aerosol mass and black carbon concentrations, a two year record at NCO-P (5079 m, Southern Himalayas)
A. Marinoni, P. Cristofanelli, P. Laj, R. Duchi, F. Calzolari, S. Decesari, K. Sellegri, E. Vuillermoz, G. P. Verza, P. Villani,P. Bonasoni
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2010,
Abstract: Aerosol mass and the absorbing fraction are important variables, needed to constrain the role of atmospheric particles in the Earth radiation budget, both directly and indirectly through CCN activation. In particular, their monitoring in remote areas and mountain sites is essential for determining source regions, elucidating the mechanisms of long range transport of anthropogenic pollutants, and validating regional and global models. Since March 2006, aerosol mass and black carbon concentration have been monitored at the Nepal Climate Observatory-Pyramid, a permanent high-altitude research station located in the Khumbu valley at 5079 m a.s.l. below Mt. Everest. The first two-year averages of PM1 and PM1 10 mass were 1.94 μg m 3 and 1.88 μg m 3, with standard deviations of 3.90 μg m 3 and 4.45 μg m 3, respectively, while the black carbon concentration average is 160.5 ng m 3, with a standard deviation of 296.1 ng m 3. Both aerosol mass and black carbon show well defined annual cycles, with a maximum during the pre-monsoon season and a minimum during the monsoon. They also display a typical diurnal cycle during all the seasons, with the lowest particle concentration recorded during the night, and a considerable increase during the afternoon, revealing the major role played by thermal winds in influencing the behaviour of atmospheric compounds over the high Himalayas. The aerosol concentration is subject to high variability: in fact, as well as frequent "background conditions" (55% of the time) when BC concentrations are mainly below 100 ng m 3, concentrations up to 5 μg m 3 are reached during some episodes (a few days every year) in the pre-monsoon seasons. The variability of PM and BC is the result of both short-term changes due to thermal wind development in the valley, and long-range transport/synoptic circulation. At NCO-P, higher concentrations of PM1 and BC are mostly associated with regional circulation and westerly air masses from the Middle East, while the strongest contributions of mineral dust arrive from the Middle East and regional circulation, with a special contribution from North Africa and South-West Arabian Peninsula in post-monsoon and winter season.
Results and recommendations from an intercomparison of six Hygroscopicity-TDMA systems
A. Massling, N. Niedermeier, T. Hennig, E. O. Fors, E. Swietlicki, M. Ehn, K. H meri, P. Villani, P. Laj, N. Good, G. McFiggans,A. Wiedensohler
Atmospheric Measurement Techniques (AMT) & Discussions (AMTD) , 2011,
Abstract: The performance of six custom-built Hygrocopicity-Tandem Differential Mobility Analyser (H-TDMA) systems was investigated in the frame of an international calibration and intercomparison workshop held in Leipzig, February 2006. The goal of the workshop was to harmonise H-TDMA measurements and develop recommendations for atmospheric measurements and their data evaluation. The H-TDMA systems were compared in terms of the sizing of dry particles, relative humidity (RH) uncertainty, and consistency in determination of number fractions of different hygroscopic particle groups. The experiments were performed in an air-conditioned laboratory using ammonium sulphate particles or an external mixture of ammonium sulphate and soot particles. The sizing of dry particles of the six H-TDMA systems was within 0.2 to 4.2% of the selected particle diameter depending on investigated size and individual system. Measurements of ammonium sulphate aerosol found deviations equivalent to 4.5% RH from the set point of 90% RH compared to results from previous experiments in the literature. Evaluation of the number fraction of particles within the clearly separated growth factor modes of a laboratory generated externally mixed aerosol was done. The data from the H-TDMAs was analysed with a single fitting routine to investigate differences caused by the different data evaluation procedures used for each H-TDMA. The differences between the H-TDMAs were reduced from +12/ 13% to +8/ 6% when the same analysis routine was applied. We conclude that a common data evaluation procedure to determine number fractions of externally mixed aerosols will improve the comparability of H-TDMA measurements. It is recommended to ensure proper calibration of all flow, temperature and RH sensors in the systems. It is most important to thermally insulate the aerosol humidification unit and the second DMA and to monitor these temperatures to an accuracy of 0.2 °C. For the correct determination of external mixtures, it is necessary to take into account size-dependent losses due to diffusion in the plumbing between the DMAs and in the aerosol humidification unit.
Looking Forward to Pricing Options from Binomial Trees
Dario Villani,Andrei E. Ruckestein
Physics , 2000,
Abstract: We reconsider the valuation of barrier options by means of binomial trees from a "forward looking" prospective rather than the more conventional "backward induction" one used by standard approaches. This reformulation allows us to write closed-form expressions for the value of European and American put barrier-options on a non-dividend-paying stock.
Monolithic Active Pixel Sensors (MAPS) in a quadruple well technology for nearly 100% fill factor and full CMOS pixels
J. A. Ballin,J. P. Crooks,P. D. Dauncey,A. -M. Magnan,Y. Mikami,O. D. Miller,M. Noy,V. Rajovic,M. M. Stanitzki,K. D. Stefanov,R. Turchetta,M. Tyndel,E. G. Villani,N. K. Watson,J. A. Wilson
Physics , 2008,
Abstract: In this paper we present a novel, quadruple well process developed in a modern 0.18mu CMOS technology called INMAPS. On top of the standard process, we have added a deep P implant that can be used to form a deep P-well and provide screening of N-wells from the P-doped epitaxial layer. This prevents the collection of radiation-induced charge by unrelated N-wells, typically ones where PMOS transistors are integrated. The design of a sensor specifically tailored to a particle physics experiment is presented, where each 50mu pixel has over 150 PMOS and NMOS transistors. The sensor has been fabricated in the INMAPS process and first experimental evidence of the effectiveness of this process on charge collection is presented, showing a significant improvement in efficiency.
A digital ECAL based on MAPS
J. A. Ballin,P. D. Dauncey,A. -M. Magnan,M. Noy,Y. Mikami,O. Miller,V. Rajovic,N. K. Watson,J. A. Wilson,J. P. Crooks,M. Stanitzki,K. D. Stefanov,R. Turchetta,M. Tyndel,E. G. Villani
Physics , 2009,
Abstract: Progress is reported on the development and testing of Monolithic Active Pixel Sensors (MAPS) for a Si-W ECAL for the ILC. Using laser and source setups, a first version of the sensor has been characterised through measurements of the absolute gain calibration, noise and pedestal. The pixel-to-pixel gain spread is 10%. Charge diffusion has been measured and found to be compatible with simulation results. The charge collected by a single pixel varies from 50% to 20% depending on where it is generated. After adding detector effects to the Geant4 simulation of an ILC-like ECAL, using the measured parameters, the energy resolution is found to be 35% higher than the ideal resolution, but is still lower than the resolution obtained for an equivalent analogue ECAL.
A MAPS-based Digital Electromagnetic Calorimeter for the ILC
J. A. Ballin,P. D. Dauncey,A. -M. Magnan,M. Noy,Y. Mikami,O. Miller,V. Rajovi?,N. K. Watson,J. A. Wilson,J. P. Crooks,M. Stanitzki,K. D. Stefanov,R. Turchetta,M. Tyndel,E. G. Villani
Physics , 2007,
Abstract: A novel design for a silicon-tungsten electromagnetic calorimeter is described, based on Monolithic Active Pixel Sensors (MAPS). A test sensor with a pixel size of 50x50 um2 has been fabricated in July 2007. The simulation of the physical sensor is done using a detailed three-dimensional charge spread algorithm. Physics studies of the sensor are done including a digitisation algorithm taking into account the charge sharing, charge collection efficiency, noise, and dead areas. The influence of the charge sharing effect is found to be important and hence needs to be measured precisely.
Seasonal variation of aerosol size distributions in the free troposphere and residual layer at the puy de D me station, France
H. Venzac, K. Sellegri, P. Villani, D. Picard,P. Laj
Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD) , 2009,
Abstract: Particle number concentration and size distribution are important variables needed to constrain the role of atmospheric particles in the Earth radiation budget, both directly and indirectly through CCN activation. They are also linked to regulated variables such as particle mass (PM) and therefore of interest to air quality studies. However, data on their long-term variability are scarce, in particular at high altitudes. In this paper, we investigate the diurnal and seasonal variability of the aerosol total number concentration and size distribution at the puy de D me research station (France, 1465 m a.s.l.). We report a variability of aerosol particle total number concentration measured over a five-year (2003–2007) period for particles larger than 10 nm and aerosol size distributions between 10 and 500 nm over a two-year period (January 2006 to December 2007). Concentrations show a strong seasonality with maxima during summer and minima during winter. A diurnal variation is also observed with maxima between 12:00 and 18:00 UTC. At night (00:00–06:00 UTC), the median hourly total concentration varies from 600 to 800 cm 3 during winter and from 1700 to 2200 cm 3 during summer. During the day (08:00–18:00 UTC), the concentration is in the range of 700 to 1400 cm 3 during winter and of 2500 to 3500 cm 3 during summer. An averaged size distribution of particles (10–500 nm) was calculated for each season. The total aerosol number concentrations are dominated by the Aitken mode integral concentrations, which drive most of the winter to summer total concentrations increase. The night to day increase in dominated by the nucleation mode integral number concentration. Because the site is located in the free troposphere only a fraction of the time, in particular at night and during the winter season, we have subsequently analyzed the variability for nighttime and free tropospheric (FT)/residual layer (RL) conditions only. We show that a seasonal variability is still observed for these FT/RL conditions. The FT/RL seasonal variation is due to both seasonal changes in the air mass origin from winter to summer and enhanced concentrations of particles in the residual layer/free troposphere in summer. The later observation can be explained by higher emissions intensity in the boundary layer, stronger exchanges between the boundary layer and the free troposphere as well as enhanced photochemical processes. Finally, aerosols mean size distributions are calculated for a given air mass type (marine/continental/regional) according to the season for the specific conditions of the residual layer/free troposphere. The seasonal variability in aerosol sources seems to be predominant over the continent compared to the seasonal variation of marine aerosol sources. These results are of regional relevance and can be used to constrain chemical-transport models over Western Europe.
Influence of semi-volatile species on particle hygroscopic growth
P. Villani,K. Sellegri,M. Monier,P. Laj
Atmospheric Chemistry and Physics Discussions , 2009,
Abstract: The hygroscopic properties of aerosol particles are often related to their content of soluble material, on the basis of the Kohler theory. Recent studies, however, seem to indicate that the role of aerosol particle semi-volatile fraction properties has been underestimated. In this study, we use a novel method based on a Tandem Differential Mobility Analyser (TDMA) system combining particle volatilization and humidification conditioning (VH-TDMA) to test the effect of the gentle volatilization of a small fraction of the atmospheric particles on the particle hygroscopic growth in several environments (urban to remote). Results show that the particle hygroscopic properties can either be enhanced or decreased after thermal conditioning of the particle at moderate temperatures (50 to 110°C). The hygroscopic growth factor changes induced by volatilization indicate that some volatile compounds, although present at low concentrations, drastically influence the hygroscopic growth of particles in the way that can not be predicted by the Kohler theory at equilibrium.
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