Search results for "colors"
showing 10 items of 37 documents
The evolution of colour pattern complexity: selection for conspicuousness favours contrasting within-body colour combinations in lizards.
2015
Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patc…
Establishing and validating a new source analysis method using phase.
2017
Electroencephalogram (EEG) measures the brain oscillatory activity non-invasively. The localization of deep brain generators of the electric fields is essential for understanding neuronal function in healthy humans and for damasking specific regions that cause abnormal activity in patients with neurological disorders. The aim of this study was to test whether the phase estimation from scalp data can be reliably used to identify the number of dipoles in source analyses. The steps performed included: i) modeling different phasic oscillatory signals using auto-regressive processes at a particular frequency, ii) simulation of two different noises, namely white and colored noise, having differen…
PENSIERI
2000
Solo poche righe, per raccontare il principio che ha guidato questa breve raccolta di riflessioni su l colore. L'argomento è talmente vasto, che ho limitato la scelta solo a quegli ambiti che, per definizione, sono molto vicini al tema. Ho scelto i pensieri in base alla semplicità di espressione e al loro potere evocativo. La selezione è stata molto severa, e cosi più della metà del materiale raccolto rimarrà solo nella memoria del computer. Ho cercato di muovermi nel tempo, captando pensieri capaci di raccontare le filosofie e gli atteggiamenti diversi che hanno segnato la storia del colore: da Lucrezio, che lo considerava altro rispetto alla materia, mutevole e totalmente dipendente dalla…
Quantum Non-Markovian Collision Models from Colored-Noise Baths
2019
A quantum collision model (CM), also known as repeated interactions model, can be built from the standard microscopic framework where a system S is coupled to a white-noise bosonic bath under the rotating wave approximation, which typically results in Markovian dynamics. Here, we discuss how to generalize the CM construction to the case of frequency-dependent system–bath coupling, which defines a class of colored-noise baths. This leads to an intrinsically non-Markovian CM, where each ancilla (bath subunit) collides repeatedly with S at different steps. We discuss the illustrative example of an atom in front of a mirror in the regime of non-negligible retardation times.
Krāsu un emociju attiecības vizuālajā komunikācijā: dažādu vecumposmu salīdzinoša analīze
2017
Darba tēma ir ‘’Krāsu un emociju attiecības vizuālajā komunikācijā: dažādu vecumposmu salīdzinoša analīze’’. Pētījuma problēma: Vai dažāda vecuma cilvēkiem atšķiras krāsu un emociju uztvere? Mērķis ir noskaidrot kā krāsu un emociju saistība mainās dažāda vecuma cilvēkiem. Darba uzdevumi ir iepazīties ar teoriju, noskaidrot krāsu un emociju saistību atšķirību dažādiem vecumposmiem, izmantojot aptauju un eksperimentu, apkopot datus un izdarīt secinājumus. Teorijā izmantotas trīs teorijas: vizuālās komunikācijas teorija, ekoloģiskās valences teorija, krāsas un emocijas. Metodoloģijā izmantotas trīs metodes: aptauja, kontentanalīze un eksperiments. Apkopojot rezultātus redzams, ka vecuma atšķir…
A novel exact representation of stationary colored Gaussian processes (fractional differential approach)
2010
A novel representation of functions, called generalized Taylor form, is applied to the filtering of white noise processes. It is shown that every Gaussian colored noise can be expressed as the output of a set of linear fractional stochastic differential equations whose solution is a weighted sum of fractional Brownian motions. The exact form of the weighting coefficients is given and it is shown that it is related to the fractional moments of the target spectral density of the colored noise.
Phase dynamics in graphene-based Josephson junctions in the presence of thermal and correlated fluctuations
2014
In this work we study by numerical methods the phase dynamics in ballistic graphene-based short Josephson junctions. The supercurrent through a graphene junction shows a non-sinusoidal phase-dependence, unlike a conventional junction ruled by the well-known d.c. Josephson relation. A superconductor-graphene-superconductor system exhibits superconductive quantum metastable states similar to those present in normal current-biased JJs. We explore the effects of thermal and correlated fluctuations on the escape time from these metastable states, when the system is stimulated by an oscillating bias current. As a first step, the analysis is carried out in the presence of an external Gaussian whit…
A Tunable Digital Ishihara Plate for Pre-School Aged Children
2016
Colors play a fundamental role for children, both in the everyday life and in education. They recognize the surrounding world, and play games making a large use of colors. They learn letters and numbers by means of colors. As a consequence, early diagnosis of color blindness is an crucial to support an individual affected by this visual perception alteration at the initial phase of his/her life. The diagnosis of red-green color deficiencies (protanopia or deuteranopia) is commonly accomplished by means of the Ishihara test, which consists of plates showing dots with different sizes where some of them compose numbers within a gamut of colors while the ones composing the background have diffe…
Recognition of unsegmented targets invariant under transformations of intensity.
2002
Images taken in noncooperative environments do not always have targets under the same illumination conditions. There is a need for methods to detect targets independently of the illumination. We propose a technique that yields correlation peaks that are invariant under a linear intensity transformation of object intensity. The new locally adaptive contrast-invariant filter accomplishes this by combining three correlations in a nonlinear way. This method is not only intensity invariant but also has good discrimination and resistance to noise. We present simulation results for various intensity transformations with and without random and correlated noise. When the noise is high enough to thre…
Experimental and numerical study of noise effects in a FitzHugh–Nagumo system driven by a biharmonic signal
2013
Abstract Using a nonlinear circuit ruled by the FitzHugh–Nagumo equations, we experimentally investigate the combined effect of noise and a biharmonic driving of respective high and low frequency F and f. Without noise, we show that the response of the circuit to the low frequency can be maximized for a critical amplitude B∗ of the high frequency via the effect of Vibrational Resonance (V.R.). We report that under certain conditions on the biharmonic stimulus, white noise can induce V.R. The effects of colored noise on V.R. are also discussed by considering an Ornstein–Uhlenbeck process. All experimental results are confirmed by numerical analysis of the system response.