Search results for "ALMA"
showing 10 items of 265 documents
Una statua fittile di divinità seduta da Capodarso: ipotesi di ricostruzione
2012
The subject of the contribution is the analysis of the lower part (feet) of a clay statue and two clay artefacts decorated with a figurative scene, all found in the anellenic site of Monte Capodarso (Enna) and datable between the 6th and the 5th century BC The latter, considered, at the time of their discovery, as parts of a trapeze, are now considered, in the light of the analysis of the clays, of the decoration and on the basis of comparisons, to be the armrests of the throne on which the figure sat, of which only the feet remain, probably a cult agalma.
Automatic detection and analysis of cell motility in phase-contrast time-lapse images using a combination of maximally stable extremal regions and Ka…
2013
Phase-contrast illumination is simple and most commonly used microscopic method to observe nonstained living cells. Automatic cell segmentation and motion analysis provide tools to analyze single cell motility in large cell populations. However, the challenge is to find a sophisticated method that is sufficiently accurate to generate reliable results, robust to function under the wide range of illumination conditions encountered in phase-contrast microscopy, and also computationally light for efficient analysis of large number of cells and image frames. To develop better automatic tools for analysis of low magnification phase-contrast images in time-lapse cell migration movies, we investiga…
NAIRU modelis Latvijas ekonomikai
2019
Darba galvenais mērķis ir aprēķināt NAIRU līkni Latvijā ar ikmēneša datiem laika posmā no 2005. gada līdz 2018.gadam, izmantojot Kalmana filtru. Teorētiskajā daļā izklāstīts bezdarba iedalījums, Filipsa līknes apraksts un matemātiskais formulējums, kā arī dažādas inflācijas prognozēšanas metodes un dabiskā bezdarba modeļu evolūcija no 20. gadsimta vidus līdz mūsdienām. Praktiskajā daļā vispirms aplūkotas dažādas laika rindas, kuras varētu būt iekļaujamas Latvijas NAIRU modelī, katrai modeļa komponentei piemeklējot 2 – 3 alternatīvus mainīgos. Turpinājumā, balstoties uz OECD metodoloģiju, iegūti un aprakstīti 2 labākie NAIRU modeļi un veikts to salīdzinājums ar līdzšinējo pētījumu rezultātie…
Zvaigžņotā Debess: 2018, Vasara (240)
2018
Jauna hipotēze par I tipa pārnovu izcelšanos ; No 108 minūtēm līdz 96 dienām ; Maiņzvaigznes (astronomija skolā) ; O.Dumbrājs. Nēteres teorēmai 100 gadu ; K.Švarcs. Jauni novērojumi tālā un tuvā kvazārā ; I.P. Īsumā: ALMA un VLT iegūst liecību par zvaigžņu veidošanos tikai 250 miljonus gadu pēc Lielā Sprādziena ; I.Pundure. Lagūnas miglājs – zvaigžņu bērnistaba Habla skatījumā ; I.Pundure. ALMA un APEX atklāj veidojošos galaktiku megasaplūšanu agrīnajā Visumā ; K.Salmiņš. LU Astronomijas institūts pirmais veicis nanopavadoņa S-NET lāzermērījumus ; J.Jaunbergs. Zeme atpakaļskata spogulī ; J.Jaunbergs. Sniegotā Helēne un mazais Polideiks ; R.Misa. Latvijas uzņēmums Eventech piedalīsies Luna-2…
Fuzzy Control Strategy for Cooperative Non-holonomic Motion of Cybercars with Passengers Vibration Analysis
2021
The cybercars are electric road wheeled non-holonomic vehicles with fully automated driving capabilities. They contribute to sustainable mobility and are employed as passenger vehicles. Non-holonomic mechanics describes the motion of the cybercar constrained by non-integrable constraints, i.e. constraints on the system velocities that do not arise from constraints on the configuration alone. First of all there are thus with dynamic nonholonomic constraints, i.e. constraints preserved by the basic Euler-Lagrange equations (Bloch, 2000; Melluso, 2007; Raimondi & Melluso, 2006-a). Of course, these constraints are not externally imposed on the system but rather are consequences of the equations…
Fuzzy EKF Control for Wheeled Nonholonomic Vehicles
2006
In this paper a new Fuzzy extended Kalman robust control system for position and orientation tracking of nonholonomic vehicles with two wheels actuated by two independent DC motors is presented. The problem of robustness and localization are solved simultaneously. About the robustness, some perturbations coming from the outside environment and depending on the contact between the wheels and the ground, involve violations of the nonholonomic constraints. The fuzzy controller of this work is able to obtain a dynamic term of robustness with respect to the perturbations above. However, by using encoders only, the measures of actual position and orientation of the vehicle are with Gaussian noise…
Predictive Intelligent Fuzzy Control for Cooperative Motion of Two Nonholonomic Wheeled Cars
2007
In this paper a problem of intelligent cooperative motion control of two wheeled nonholonomic cars (target and follower) is considered. Once a target car converges to a fixed state (position and orientation), a follower car coming from different position and orientation, converges to the state above, without excessive delay between the known arrival time of the target car and the arrival time of the follower. In this sense we present a new predictive fuzzy control system. A Kalman's filter and an odometric model are used to predict the future position and orientation of the target car. The prediction above is employed to plane a circular nonholonomic reference motion for the follower car. A…
Le filtre de Kalman étendu à grand-gain adaptatif et ses applications
2010
The work concerns the “observability problem”—the reconstruction of a dynamic process’s full state from a partially measured state— for nonlinear dynamic systems. The Extended Kalman Filter (EKF) is a widely-used observer for such nonlinear systems. However it suffers from a lack of theoretical justifications and displays poor performance when the estimated state is far from the real state, e.g. due to large perturbations, a poor initial state estimate, etc. . . We propose a solution to these problems, the Adaptive High-Gain (EKF). Observability theory reveals the existence of special representations characterizing nonlinear systems having the observability property. Such representations ar…
Convergence analysis of cubature Kalman filter
2014
This paper investigates the stability analysis of cubature Kalman filter (CKF) for nonlinear systems with linear measurement. The certain conditions to ensure that the estimation error of CKF remains bounded are proved. Then, the effect of process noise covariance is investigated and an adaptive process noise covariance is proposed to deal with large estimation error. Accordingly, a modified CKF (MCKF) is developed to enhance the stability and accuracy of state estimation. The performance of the MCKF is compared to the CKF by two case studies. Simulation results demonstrate that the large estimation error may lead to instability of CKF while the MCKF is successfully able to estimate the sta…
Sustainable Method Using Filtering Techniques for a Fermentation Process State Estimation
2020
Winemaking is concerned about sustainable energy availability that implies new methods for process monitoring and control. The aim of this paper is to realize a comparative analysis of the possibilities offered using estimation techniques, balances, and filtering techniques such as the Kalman filter (KF) and the extended Kalman filter (EKF), to obtain indirect information about the alcoholic fermentation process during winemaking. Thus, an estimation solution of the process variables in the exponential growing phase is proposed, using an extended observer. In addition, two estimation solutions of this process with the EKF and an estimation of the decay phase of the fermentation process are …