References of "Nicolay, Samuel"      in Complete repository Arts & humanities   Archaeology   Art & art history   Classical & oriental studies   History   Languages & linguistics   Literature   Performing arts   Philosophy & ethics   Religion & theology   Multidisciplinary, general & others Business & economic sciences   Accounting & auditing   Production, distribution & supply chain management   Finance   General management & organizational theory   Human resources management   Management information systems   Marketing   Strategy & innovation   Quantitative methods in economics & management   General economics & history of economic thought   International economics   Macroeconomics & monetary economics   Microeconomics   Economic systems & public economics   Social economics   Special economic topics (health, labor, transportation…)   Multidisciplinary, general & others Engineering, computing & technology   Aerospace & aeronautics engineering   Architecture   Chemical engineering   Civil engineering   Computer science   Electrical & electronics engineering   Energy   Geological, petroleum & mining engineering   Materials science & engineering   Mechanical engineering   Multidisciplinary, general & others Human health sciences   Alternative medicine   Anesthesia & intensive care   Cardiovascular & respiratory systems   Dentistry & oral medicine   Dermatology   Endocrinology, metabolism & nutrition   Forensic medicine   Gastroenterology & hepatology   General & internal medicine   Geriatrics   Hematology   Immunology & infectious disease   Laboratory medicine & medical technology   Neurology   Oncology   Ophthalmology   Orthopedics, rehabilitation & sports medicine   Otolaryngology   Pediatrics   Pharmacy, pharmacology & toxicology   Psychiatry   Public health, health care sciences & services   Radiology, nuclear medicine & imaging   Reproductive medicine (gynecology, andrology, obstetrics)   Rheumatology   Surgery   Urology & nephrology   Multidisciplinary, general & others Law, criminology & political science   Civil law   Criminal law & procedure   Criminology   Economic & commercial law   European & international law   Judicial law   Metalaw, Roman law, history of law & comparative law   Political science, public administration & international relations   Public law   Social law   Tax law   Multidisciplinary, general & others Life sciences   Agriculture & agronomy   Anatomy (cytology, histology, embryology...) & physiology   Animal production & animal husbandry   Aquatic sciences & oceanology   Biochemistry, biophysics & molecular biology   Biotechnology   Entomology & pest control   Environmental sciences & ecology   Food science   Genetics & genetic processes   Microbiology   Phytobiology (plant sciences, forestry, mycology...)   Veterinary medicine & animal health   Zoology   Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences   Chemistry   Earth sciences & physical geography   Mathematics   Physics   Space science, astronomy & astrophysics   Multidisciplinary, general & others Social & behavioral sciences, psychology   Animal psychology, ethology & psychobiology   Anthropology   Communication & mass media   Education & instruction   Human geography & demography   Library & information sciences   Neurosciences & behavior   Regional & inter-regional studies   Social work & social policy   Sociology & social sciences   Social, industrial & organizational psychology   Theoretical & cognitive psychology   Treatment & clinical psychology   Multidisciplinary, general & others     Showing results 1 to 20 of 106 1 2 3 4 5 6     A multifractal formalism for non-concave and non-increasing spectra: the leaders profile methodEsser, Céline ; Kleyntssens, Thomas ; Nicolay, Samuel in Applied & Computational Harmonic Analysis (in press)We present an implementation of a multifractal formalism based on the types of histogram of wavelet leaders. This method yields non-concave spectra and is not limited to their increasing part. We show ... [more ▼]We present an implementation of a multifractal formalism based on the types of histogram of wavelet leaders. This method yields non-concave spectra and is not limited to their increasing part. We show both from the theoretical and from the applied points of view that this approach is more e cient than the wavelet-based multifractal formalisms previously introduced. [less ▲]Detailed reference viewed: 63 (21 ULg) About the multifractal nature of Cantor's bijection: Bounds for the Hölder exponent at almost every irrational pointNicolay, Samuel ; Simons, Laurentin Fractals (2016), 24(2), 1650014-1-1650014-9In this note, we investigate the regularity of Cantor’s one-to-one mapping between the irrational numbers of the unit interval and the irrational numbers of the unit square. In particular, we explore the ... [more ▼]In this note, we investigate the regularity of Cantor’s one-to-one mapping between the irrational numbers of the unit interval and the irrational numbers of the unit square. In particular, we explore the fractal nature of this map by showing that its Hölder regularity lies between 0.35 and 0.72 almost everywhere (with respect to the Lebesgue measure). [less ▲]Detailed reference viewed: 13 (4 ULg) A Refined Method for Estimating the Global Hölder ExponentKleyntssens, Thomas ; Kreit, Damien; Nicolay, Samuel Conference (2016, April 12)We give a wavelet characterization of the generalized Hölder spaces and show how this result can be applied to detect logarithmic corrections appearing in Brownian processes.Detailed reference viewed: 40 (9 ULg) [Beamer] A New Wavelet-Based Mode Decomposition for Oscillating Signals and Comparison with the Empirical Mode DecompositionDeliège, Adrien ; Nicolay, Samuel Conference (2016, April)We introduce a new method based on wavelets (EWMD) for decomposing a signal into quasi-periodic oscillating components with smooth time-varying amplitudes. This method is inspired by both the “classic” ... [more ▼]We introduce a new method based on wavelets (EWMD) for decomposing a signal into quasi-periodic oscillating components with smooth time-varying amplitudes. This method is inspired by both the “classic” wavelet-based decomposition and the empirical mode decomposition (EMD). We compare the reconstruction skills and the period detection ability of the method with the well-established EMD on toys examples and the ENSO climate index. It appears that the EWMD accurately decomposes and reconstructs a given signal (with the same efficiency as the EMD), it is better at detecting prescribed periods and is less sensitive to noise. This work provides the first version of the EWMD. Even though there is still room for improvement, it turns out that preliminary results are highly promising. [less ▲]Detailed reference viewed: 43 (8 ULg) Mars Topography Investigated Through the Wavelet Leaders Method: a Multidimensional Study of its Fractal StructureDeliège, Adrien ; Kleyntssens, Thomas ; Nicolay, Samuel Poster (2016, April)This work examines the scaling properties of Mars topography through a wavelet-based formalism. We conduct exhaustive one-dimensional (both longitudinal and latitudinal) and two-dimensional studies based ... [more ▼]This work examines the scaling properties of Mars topography through a wavelet-based formalism. We conduct exhaustive one-dimensional (both longitudinal and latitudinal) and two-dimensional studies based on Mars Orbiter Laser Altimeter (MOLA) data using the multifractal formalism called Wavelet Leaders Method (WLM). This approach shows that a scale break occurs at approximately 15 km, giving two scaling regimes in both 1D and 2D cases. At small scales, these topographic profiles mostly display a monofractal behavior while a switch to multifractality is observed in several areas at larger scales. The scaling exponents extracted from this framework tend to be greater at small scales. In the 1D context, these observations are in agreement with previous works and thus suggest that the WLM is well-suited for examining scaling properties of topographic fields. Moreover, the 2D analysis is the first such complete study to our knowledge. It gives both a local and global insight on the scaling regimes of the surface of Mars and allows to exhibit the link between the scaling exponents and several famous features of the Martian topography. These results may be used as a solid basis for further investigations of the scaling laws of the Red planet and show that the WLM could be used to perform systematic analyses of the surface roughness of other celestial bodies. [less ▲]Detailed reference viewed: 19 (4 ULg) A New Wavelet-Based Mode Decomposition for Oscillating Signals and Comparison with the Empirical Mode DecompositionDeliège, Adrien ; Nicolay, Samuel in Information Technology: New Generations (2016, April)We introduce a new method based on wavelets (EWMD) for decomposing a signal into quasi-periodic oscillating components with smooth time-varying amplitudes. This method is inspired by both the “classic” ... [more ▼]We introduce a new method based on wavelets (EWMD) for decomposing a signal into quasi-periodic oscillating components with smooth time-varying amplitudes. This method is inspired by both the “classic” wavelet-based decomposition and the empirical mode decomposition (EMD). We compare the reconstruction skills and the period detection ability of the method with the well-established EMD on toys examples and the ENSO climate index. It appears that the EWMD accurately decomposes and reconstructs a given signal (with the same efficiency as the EMD), it is better at detecting prescribed periods and is less sensitive to noise. This work provides the first version of the EWMD. Even though there is still room for improvement, it turns out that preliminary results are highly promising. [less ▲]Detailed reference viewed: 51 (27 ULg) The Fractal Nature of Mars Topography Analyzed via the Wavelet Leaders MethodKleyntssens, Thomas ; Deliège, Adrien ; Nicolay, Samuel in Information Technology: New Generations (2016, April)This paper studies the scaling properties of Mars topography based on Mars Orbiter Laser Altimeter (MOLA) data through the wavelet leaders method (WLM). This approach shows a scale break at 15 km. At ... [more ▼]This paper studies the scaling properties of Mars topography based on Mars Orbiter Laser Altimeter (MOLA) data through the wavelet leaders method (WLM). This approach shows a scale break at 15 km. At small scales, these topographic profiles display a monofractal behavior while a multifractal nature is observed at large scales. The scaling exponents are greater at small scales. They also seem to be influenced by latitude and may indicate a slight anisotropy in topography. [less ▲]Detailed reference viewed: 32 (19 ULg) A Refined Method for Estimating the Global Hölder ExponentNicolay, Samuel ; Kreit, Damienin Latifi, Shahram (Ed.) Information Technology: New Generations (2016, April)In this paper, we recall basic results we have obtained about generalized Hölder spaces and present a wavelet characterization that holds under more general hypothesis than previously stated. This ... [more ▼]In this paper, we recall basic results we have obtained about generalized Hölder spaces and present a wavelet characterization that holds under more general hypothesis than previously stated. This theoretical tool gives rise to a method for estimating the global Hölder exponent which seems to be more precise than other wavelet-based approaches. This work should prove helpful for estimating long range correlations. [less ▲]Detailed reference viewed: 17 (7 ULg) Wavelet-based Methods to Study the Regularity of a Signal: from Theory to PracticeKleyntssens, Thomas ; Nicolay, Samuel Conference (2016, March 23)In this talk, I use the notion of wavelet to design multifractal formalisms. I present the theoritical results obtained on the generalized Snu spaces and I show the utility of these generalization ... [more ▼]In this talk, I use the notion of wavelet to design multifractal formalisms. I present the theoritical results obtained on the generalized Snu spaces and I show the utility of these generalization. Besides, I also apply these formalisms on a practical example: the Mars topography. [less ▲]Detailed reference viewed: 18 (3 ULg) Some characterizations about Generalized Hölder-Zygmund Spaces Λ_{σ,N}^{α}(R^d)Kreit, Damien ; Nicolay, Samuel E-print/Working paper (2016)Generalized Hölder-Zygmund spaces $\Lambda_{\sigma, N}^{\alpha}(\R^{d})$ were recently introduced and are based on a generalization of Besov spaces. Under some conditions, generalized Hölder-Zygmund and ... [more ▼]Generalized Hölder-Zygmund spaces $\Lambda_{\sigma, N}^{\alpha}(\R^{d})$ were recently introduced and are based on a generalization of Besov spaces. Under some conditions, generalized Hölder-Zygmund and Besov spaces are equal. It has been proved that most properties of classical Hölder-Zygmund spaces are held for spaces $\Lambda^{\sigma,\alpha}(\R^{d})$, which constitute a particular case of spaces $\Lambda_{\sigma, N}^{\alpha}(\R^{d})$ with $N_{j}=2^{j}$. The goal of the present document is to prove that most of these properties are kept for $\Lambda_{\sigma, N}^{\alpha}(\R^{d})$ spaces. [less ▲]Detailed reference viewed: 12 (2 ULg) Une construction des nombres hyperréelsNicolay, Samuel in Quadrature : Magazine de Mathématiques Pures et Appliquées (2016), 102Nous proposons ici une brève construction classique des nombres hyperréels à partir des nombres réels. Dans un soucis de pédagogie, nous omettons les détails les plus techniques. La présentation est ... [more ▼]Nous proposons ici une brève construction classique des nombres hyperréels à partir des nombres réels. Dans un soucis de pédagogie, nous omettons les détails les plus techniques. La présentation est divisée en deux parties. La première fait presqu' exclusivement appel à l'intuition, tandis que la seconde reprend les mêmes linéaments mais se veut plus rigoureuse. [less ▲]Detailed reference viewed: 25 (0 ULg) Köppen–Geiger Climate Classification for Europe Recaptured via the Hölder Regularity of Air Temperature DataDeliège, Adrien ; Nicolay, Samuel in Pure and Applied Geophysics (2016), 173In this paper, we make use of the monoHölder nature of surface air temperature data to recapture the Köppen–Geiger climate classification in Europe. Using data from the European climate Assessment and ... [more ▼]In this paper, we make use of the monoHölder nature of surface air temperature data to recapture the Köppen–Geiger climate classification in Europe. Using data from the European climate Assessment and Dataset (ECA&D), we first show that the Ho ̈lder exponents of surface air temperature data are statistically related to pressure anomalies. Then, we establish a climate classification based on these Hölder exponents in such a way that it allows to recover the Ko ̈ppen–Geiger climate classification. We show that the two classifications match for a vast majority of stations, and we corroborate these observations with a confirmation test. We compare these results with those obtained with another dataset (NCEP-NCAR Reanalysis Project) to show that the new classification is still well-adapted, before eventually discussing these findings. [less ▲]Detailed reference viewed: 31 (19 ULg) The Fractal Nature of Mars Topography Analyzed via the Wavelet Leaders MethodKleyntssens, Thomas ; Deliège, Adrien ; Nicolay, Samuel Poster (2016)This work studies the scaling properties of Mars topography based on Mars Orbiter Laser Altimeter (MOLA) data through the wavelet leaders method (WLM). This approach shows a scale break at 15 km. At small ... [more ▼]This work studies the scaling properties of Mars topography based on Mars Orbiter Laser Altimeter (MOLA) data through the wavelet leaders method (WLM). This approach shows a scale break at 15 km. At small scales, these topographic profiles display a monofractal behavior while a multifractal nature is observed at large scales. The scaling exponents are greater at small scales. They also seem to be influenced by latitude and may indicate a slight anisotropy in topography. [less ▲]Detailed reference viewed: 27 (13 ULg) About the Uniform Hölder Continuity of Generalized Riemann FunctionBastin, Françoise ; Nicolay, Samuel ; Simons, Laurent in Mediterranean Journal of Mathematics (2016), 13(1), 101-117In this paper, we study the uniform H\"{o}lder continuity of the generalized Riemann function~$R_{\alpha,\beta}$ (with $\alpha>1$ and $\beta>0$) defined by $R_{\alpha,\beta}(x)=\sum_{n=1}^{+\infty}\frac ... [more ▼]In this paper, we study the uniform H\"{o}lder continuity of the generalized Riemann function~R_{\alpha,\beta} (with \alpha>1 and \beta>0) defined by \[ R_{\alpha,\beta}(x)=\sum_{n=1}^{+\infty}\frac{\sin(\pi n^\beta x)}{n^\alpha},\quad x\in\mathbb{R},$ using its continuous wavelet transform. In particular, we show that the exponent we find is optimal. We also analyse the behaviour of~$R_{\alpha,\beta}$ as $\beta$ tends to infinity. [less ▲]Detailed reference viewed: 55 (16 ULg) On generalized Hölder spacesKreit, Damien; Nicolay, Samuel Conference (2015, September 24)We introduce generalized pointwise Hölder spaces as the point wise version of generalized uniform Hölder spaces. These last ones can be seen as a special case of generalized Besov spaces.Detailed reference viewed: 20 (3 ULg) Use of the wavelet theory as a tool to investigate the l-abelian complexity of a sequenceKleyntssens, Thomas ; Nicolay, Samuel ; Vandomme, Elise et alPoster (2015, September 23)The concept of k-automatic sequences is at the intersection of number theory and formal language theory. It has been generalized by the notion of k-regularity that allows to study sequences with values in ... [more ▼]The concept of k-automatic sequences is at the intersection of number theory and formal language theory. It has been generalized by the notion of k-regularity that allows to study sequences with values in a (possibly infinite) ring. This concept provides us with structural information about how the different terms of the sequence are related to each other. They are many different notions related to the measure of complexity of an infinite sequence w. A classical approach is its factor complexity. In an abelian context, the analogue to the factor complexity is the abelian complexity where the number of distinct factors of length n is counted up to abelian equivalence. The notion of abelian complexity was extended to that of l-abelian complexity. In this talk, I propose to use tools from the wavelet theory to analyze the l-abelian complexity. For the numerical simulations, I apply the wavelet leaders method that allows to study the pointwise regularity of signals. [less ▲]Detailed reference viewed: 25 (8 ULg) A wavelet-based mode decomposition compared to the EMDDeliège, Adrien ; Nicolay, Samuel Poster (2015, September 08)We introduce a new method based on wavelets for decomposing a signal into quasi-periodic oscillating components with smooth time-varying amplitudes. This method is inspired by both the "classic" wavelet ... [more ▼]We introduce a new method based on wavelets for decomposing a signal into quasi-periodic oscillating components with smooth time-varying amplitudes. This method is inspired by both the "classic" wavelet-based decomposition and the empirical mode decomposition (EMD). We compare the efficiency of the method with the well-established EMD on toys examples and the ENSO climate index. [less ▲]Detailed reference viewed: 74 (12 ULg) The leaders profile method: detection of distinct processes in a signalKleyntssens, Thomas ; Nicolay, Samuel Poster (2015, September 08)The leaders profile method is a multifractal formalism that allows to compute non-concave and non-increasing spectra. Our implementation can detect the presence of distinct processes in a signal. We ... [more ▼]The leaders profile method is a multifractal formalism that allows to compute non-concave and non-increasing spectra. Our implementation can detect the presence of distinct processes in a signal. We present here the first results obtained. [less ▲]Detailed reference viewed: 31 (10 ULg) Les nombresNicolay, Samuel Book published by Hermann (2015)Cet ouvrage présente une construction axiomatique des nombres basée sur la théorie des ensembles. Les nombres naturels, entiers, rationnels, réels et hyperréels sont introduits.Detailed reference viewed: 93 (12 ULg) Les algorithmes : entre quotidien et créativitéNicolay, Samuel ; Kleyntssens, Thomas ; Mainz, Isabelle Conference given outside the academic context (2015)Detailed reference viewed: 30 (7 ULg)