Search results for "SIM"
showing 10 items of 10139 documents
A microsimulation calibration methodology based on speed-density relationships for freeways
2014
This paper describes the calibration methodology based on speed-density relationships in the microsimulation calibration process, stated that they represent the traffic flow phenomenon in a wide range of operational conditions and well summarize all the information that may be collected on field (or following a run of the microsimulation model) on two of the three key variables of traffic flow. The matching of speed-density relationships from field and simulation was evaluated using statistical analysis as technique of pattern recognition. A test freeway segment under uncongested traffic conditions was selected as case study; based on traffic data observed at A22 Brenner Freeway, Italy, sta…
Tuning protein adsorption on graphene surfaces via laser-induced oxidation
2021
An approach for controlled protein immobilization on laser-induced two-photon (2P) oxidation patterned graphene oxide (GO) surfaces is described. Selected proteins, horseradish peroxidase (HRP) and biotinylated bovine serum albumin (b-BSA) were successfully immobilized on oxidized graphene surfaces, via non-covalent interactions, by immersion of graphene-coated microchips in the protein solution. The effects of laser pulse energy, irradiation time, protein concentration and duration of incubation on the topography of immobilized proteins and consequent defects upon the lattice of graphene were systemically studied by atomic force microscopy (AFM) and Raman spectroscopy. AFM and fluorescence…
Studying the Cognitive Map of the US States: Ideology and Prosperity Stereotypes Predict Interstate Prejudice
2018
What are the spontaneous stereotypes that U.S. citizens hold about the U.S. states? We complemented insights from theory-driven approaches to this question with insights from a novel data-driven approach. Based on pile sorting and spatial arrangement similarity ratings for the states, we computed two cognitive maps of the states. Based on ratings for the states on ∼20 candidate dimensions, we interpreted the dimensions that spanned the two maps (Studies 1 and 2). Consistent with the agency/socioeconomic success, conservative-progressive beliefs, and communion (ABC) model of spontaneous stereotypes, these dimensions that participants spontaneously used to rate the states’ similarity included…
Līdzsvara figūras un dinamika magnētiskā šķidruma pilienam ārējā laukā
2016
Līdzsvara figūras rotējošām pašgravitējošiem šķidruma pilieniem ir pētītas vairāk nekā 100 gadus, bet tikai nesen tās iegūtas eksperimentāli pilienam veidotam no magnētiskā šķidruma. Iepriekš kvalitatīvi modeļi ir izmantoti to aprakstam, kurus šeit pārbaudu ar skaitlisku simulāciju. Šajā darbā izmantoju 3D robežintegrālvienādojumu formulējumu, ar kuru magnētisko lauku uz virsmas aprēķinu ar jaunu robeželementu metodes algoritmu un kurā izvairos no tieša liekuma rēķināšanas, izmantojot integrālās transformācijas. Skaitliskais algoritms ir testēts magnētiskā lauka aprēķinam elipsoīdā, izstiepta piliena relaksācijai, pielienu izstiepšanai konstantā laukā un tā saspiešanai rotējošā augstfrekven…
SNP and SML estimation of univariate and bivariate binary–choice models
2008
We discuss the semi-nonparametric approach of Gallant and Nychka (1987, Econometrica 55: 363–390), the semiparametric maximum likelihood approach of Klein and Spady (1993, Econometrica 61: 387–421), and a set of new Stata commands for semiparametric estimation of three binary-choice models. The first is a univariate model, while the second and the third are bivariate models without and with sample selection, respectively. The proposed estimators are root-n consistent and asymptotically normal for the model parameters of interest under weak assumptions on the distribution of the underlying error terms. Our Monte Carlo simulations suggest that the efficiency losses of the semi-nonparametric a…
Can the adaptive Metropolis algorithm collapse without the covariance lower bound?
2011
The Adaptive Metropolis (AM) algorithm is based on the symmetric random-walk Metropolis algorithm. The proposal distribution has the following time-dependent covariance matrix at step $n+1$ \[ S_n = Cov(X_1,...,X_n) + \epsilon I, \] that is, the sample covariance matrix of the history of the chain plus a (small) constant $\epsilon>0$ multiple of the identity matrix $I$. The lower bound on the eigenvalues of $S_n$ induced by the factor $\epsilon I$ is theoretically convenient, but practically cumbersome, as a good value for the parameter $\epsilon$ may not always be easy to choose. This article considers variants of the AM algorithm that do not explicitly bound the eigenvalues of $S_n$ away …
Measurement of the Higgs boson coupling with tau leptons and search for an additional neutral MSSM Higgs boson with the ATLAS detector
2018
El Modelo Estándar de física de partículas (SM), la teoría que describe el comportamiento de las partículas subatómicas, ha sido un éxito en su precisión y exactitud. Uno de sus pilares básicos es el mecanismo de Higgs, que regula los términos de masa de las partículas fundamentales. La partícula responsable de este mecanismo es el bosón de Higgs, que fue descubierto en 2012 en los experimentos ATLAS y CMS del colisionador de partículas LHC del CERN, mediante el análisis de su acoplamiento a partículas bosónicas (fotones y bosones W y Z). Tras su descubrimiento, es necesario confirmar que el resto sus propiedades se corresponden con las predichas por el SM, como, por ejemplo, su acoplamient…
Modeling and Backstepping Control of the Electronic Throttle System
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/871674 Open access Electronic throttle is widely used in modern automotive engines. An electronic throttle system regulates the throttle plate angle by using a DC servo motor to adjust the inlet airflow rate of an internal combustion engine. Its application leads to improvements in vehicle drivability, fuel economy, and emissions. In this paper, by taking into account the dynamical behavior of the electronic throttle, the mechanism model is first built, and then the mechanism model is transformed into the state-space model. Based on the s…
Kinematic and Elastostatic Design Optimisation of the 3-DOF Gantry-Tau Parallel Kinematic Manipulator
2009
Published version of an article in the journal: Modeling Identification and Control. Also available from the publisher:http://dx.doi.org/10.4173/mic.2009.2.1 One of the main advantages of the Gantry-Tau machine is a large accessible workspace/footprint ratio compared to many other parallel machines. The Gantry-Tau improves this ration further by allowing a change of assembly mode without internal link collisions or collisions between the links and end-effector. The reconfigurable Gantry-Tau kinematic design obtained by multi-objective optimisation according to this paper gives the following features: 3-D workspace/footprint ration is more than 3.19, lowest Cartesian stiffness in the workspa…