2,047 research outputs found
Facial Features Detection and Grouping
Tato bakalářská práce se zabývá detekcí obličeje a obličejových rysů v obraze. Zaměřuje se především na metodu, která využívá k detekci barevného modelu lidské kůže. Touto metodou nalezne všechny body odpovídající barvě kůže a pomocí morfologických operací shlukne body do kandidátních oblastí obličeje a následně v nich vyhledá pomocí Sobelova operátoru obličejové rysy. Obsahem je také částečná implementace detektoru v jazyce C za pomocí knihovny OpenCV.This bachelor's thesis deals with facial features detection in images. Especially, a skin color detection algorithm is addressed. This method find all pixels corresponding to the skin color and clusters them into candidate face regions by the help of morfological operations. Afterwards, using the Sobel operator, all facial features are located accurately. Implementation of the proposed facial feature detector based on the well known OpenCV library is presented too.
Constraints on Compact Binary Formation and Effective Gravitational Wave Likelihood Approximation
Since the initial discovery of gravitational-waves from merging black holes, the LIGO Scientific Collaboration together with Virgo and KAGRA have published 90 gravitational-wave observations of compact binary mergers in the Gravitational-Wave Transient Catalog papers. One of the quintessential questions of this decade in gravitational-wave astronomy is the characterization and impact of the population of observed gravitational-wave signals from merging black holes and neutron stars. Now, there is greater incentive than ever to study the formation channels for these compact binary mergers. In this work, we carry out an investigation of isolated binary evolution formation channel, comparing predictions of the gravitational-wave population from the StarTrack synthetic universe simulations to the observed population of compact binary mergers in order to constrain certain astrophysical processes in binary evolution. In due course, we construct, apply, and provide parametric and non-parametric models for the likelihood function of the full set of astrophysical parameters of each event in the Gravitational-Wave Transient Catalogs, including truncated multivariate normal distributions normalized on a bounded interval, which we have shared in our associated publications [63, 64]. We present the findings of our investigation of the formation parameters for the isolated binary evolution formation channel for compact objects. We have uncovered confounding systematic effects in our model by considering the agreement and disagreement of predictions based on the event rate and mass distribution. Furthermore, our preliminary results demonstrate the benefits of a multi-dimensional analysis which is sensitive to the interdependence of the predicted detection population on many formation parameters. Our essential contribution is therefore a method for carrying out such an analysis efficiently, while considering its self-consistency. We discuss potential sources of bias as we also present the properties of our best binary evolution models, which are consistent with unrestricted stellar mass loss due to winds, high mass and angular momentum loss to ejected portions of a common envelope, and substantial black hole supernova recoil kicks. We conclude with a discussion of the impact of these activities for gravitational-wave and multi-messenger astronomy
Linear Time Periodic Analysis of Dc-Dc converter
Aim of this thesis is to analyze Dc-Dc converters by using the techniques of Linear Periodic Time varying (LTP) systems to estimate the amount of subharmonics injected in the load. Dc-Dc converters are used to transform a Dc input to a Dc output of different voltage. In this thesis we study in particular the so called "switch mode" converters. In this kind of devices the conversion is obtained by using fast commutations of (at least) two switches. Due to the discrete switch-positions these converters are considered a typical example of hybrid systems. Linear models with fixed coefficients (LTI system) give a description of the system inadequate to predict and to analyze harmonic effects, while linear models with coefficients that vary periodically, namely LTP system, can be used effectively to this aim. We use therefore a Linear Time Periodic (LTP) system to describe the converter. This kind of description in much more accurate but the model and the tools used to study it are more complex. In the thesis we first introduce the LTP system theory and its main results. In particular we introduce the concept of Harmonic Transfer Function (HTF). A LTP model for a Dc-Dc converter is then derived and it is shown that this model accurately describes the response of the converter. Furthermore this LTP model is used to analyze the open and closed loop behavior of the system. It is shown that the linear model estimates correctly the amplitude of the subharmonics in the output. The thesis has been developed at the Automatic Control Department, Lund University, Sweden under the supervision of Andreas Wernrud and Anders Rantzer. The Italian supervisor of this thesis is Giorgio Picci, Dipartimento di Ingegneria dell' Informazione, Università degli studi di Padova, Ital
Beyond the economics of the euro - analysing the institutional evolution of EMU 1999-2010, September 2011
This Occasional Paper examines how and why the institutional framework governing EMU has evolved since the creation of the euro. Building on theories of institutionalism, the paper in particular investigates to what extent functional spillovers from the single currency into other policy domains, like macroeconomic policies or financial regulation, met with an adequate institutional response, and to what extent the existing institutional framework conditioned the response to the financial crisis. The interaction between policy requirements and institutional capabilities is examined both in “ordinary times” (1999-2007) and under “crisis conditions” (2007-10). The paper uses a typology of change which helps to put into perspective both the resilience of the institutional framework of EMU and its capacity to adapt. In this respect, it allows for a better understanding and framing of the current reforms of EMU economic governance. It concludes that even though the crisis will accelerate institutional development, it will do so only gradually, as path dependence and an inbuilt bias towards incremental change will prevent policy-makers from pursuing a “clean slate” strategy. JEL Classification: E52, E31, D84EMU institutional architecture, historical institutionalism, institutional change., rational choice
Recommended from our members
Integrating Biophysics in Toxicology
Integration of biophysical stimulation in test systems is established in diverse branches of biomedical sciences including toxicology. This is largely motivated by the need to create novel experimental setups capable of reproducing more closely in vivo physiological conditions. Indeed, we face the need to increase predictive power and experimental output, albeit reducing the use of animals in toxicity testing. In vivo, mechanical stimulation is essential for cellular homeostasis. In vitro, diverse strategies can be used to model this crucial component. The compliance of the extracellular matrix can be tuned by modifying the stiffness or through the deformation of substrates hosting the cells via static or dynamic strain. Moreover, cells can be cultivated under shear stress deriving from the movement of the extracellular fluids. In turn, introduction of physical cues in the cell culture environment modulates differentiation, functional properties, and metabolic competence, thus influencing cellular capability to cope with toxic insults. This review summarizes the state of the art of integration of biophysical stimuli in model systems for toxicity testing, discusses future challenges, and provides perspectives for the further advancement of in vitro cytotoxicity studies
A nonparametric approach for model individualization in an artificial pancreas
The identification of patient-tailored linear time invariant glucose-insulin models is investigated for type 1 diabetic patients, that are characterized by a substantial inter-subject variability. The individualized linear models are identified by considering a novel kernel-based nonparametric approach and are compared with a linear time invariant average model in terms of prediction performance by means of the coefficient of determination, fit, positive and negative max errors, and root mean squared error. Model identification and validation are based on in-silico data collected from the adult virtual population of the UVA/Padova simulator. The data generation involves a protocol designed to produce a sufficient input excitation without compromising patient safety, compatible also with real life scenarios. The identified models are exploited to synthesize an individualized Model Predictive Controller (MPC) for each patient, which is used in an Artificial Pancreas to maintain the blood glucose concentration within an euglycemic range. The MPC used in several clinical studies, synthesized on the basis of a non-individualized average linear time invariant model, is also considered as reference. The closed-loop control performance is evaluated in an in-silico study on the adult virtual population of the UVA/Padova simulator in a perturbed scenario, in which the MPC is blind to random variations of insulin sensitivity in each virtual patient. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved
Developing biodiversity assessment on a stand forest type management level in north-eastern Italy
This paper discusses a simple operative proposal, elaborated by a team of advisers
to the Forestry Service of the Veneto administrative region (north-eastern Italy), concerning
the definition of stand-level forest type biodiversity indicators and biodiversity
oriented management provisions. Such tools are conceived to transfer biodiversity conservation
understanding in current forest stand management practices. The developed
assessment system is targeted to: maintenance and increase of the variability of forest
landscape mosaic; conservation of species variability; creation of resource reservoirs. The
following criteria and indicators are taken into consideration: spatial pattern (widespreadness,
connectedness, species contagion potential), forest structure (uneven aged
stands: percent of trees in three broad diameter classes; even aged stands: number of
development stages and surface of each development stage), herbs/shrubs species (average,
minimum and maximum number of species; average number of short-lived herb/
shrub species recorded in minimal anthropic disturbance conditions; dynamic trend in
the number of herb/shrub species), bird species (average, minimum and maximum
number of species); overall naturalistic quality (flora; vegetation; fauna). Such indicators
are proposed as biodiversity reference standards for each forest type in the considered
region: they provide practical baseline information with which forest stand management
efficiency in achieving biodiversity targets can be compared
Consistency of Microstructural Modeling of Micelles: Letter Concerning “Thermotropic Behavior and Stability of Monosialoganglioside Micelles in Aqueous Solution”
- …