197,805 research outputs found
Deux siècles avant Parmentier... F. Hasler et M. Louisa Portmann, Bauhin der J. (1541-1613) in Gesnerus, 1963
No full textGuitard Eugène-Humbert. Deux siècles avant Parmentier... F. Hasler et M. Louisa Portmann, Bauhin der J. (1541-1613) in Gesnerus, 1963. In: Revue d'histoire de la pharmacie, 52ᵉ année, n°180, 1964. p. 46
Substrate specificity and fine-scale distribution of epiphytic diatoms in a shallow tarn in the Brenta Dolomites (South-eastern Alps)
No full textBackground and aims – The host-specificity of epiphytic diatom species has long been debated. Scuba divers sampled epiphytic diatoms in the shallow Alpine Lake Valagola (average depth c. 2 m) along seven transects (length: 30–144 m) in West-East direction. The bottom of the tarn was covered by macrophytes dominated by Chara aspera and Potamogeton gramineus. Factors affecting epiphytic-diatom spatial distribution at a fine scale were tested. Methods – Dataset was tested using Redundancy Analysis (CANOCO package) and one-way ANOVA (NCSS package). Key results – The analysis separated sampling sites into two groups: the tarn shore dominated by Potamogeton gramineus, and the central area dominated by Chara aspera. Diatom species richness, diversity, and composition differed significantly between the two main host plants. Potamogeton gramineus assemblages were characterized by higher species richness and diversity, and by the large-celled, adnate diatom species Epithemia adnata, Rhopalodia gibba, Eunotia arcus and E. arcubus. Chara aspera was preferred by the small-celled, motile diatom species Brachysira neoexilis and Encyonopsis cesatii. Conclusions – The spatial distribution of epiphytic diatoms in the shallow, oligo-mesotrophic Lake Valagola is influenced by host plant composition and distribution. Epiphyton size structure suggests that Chara represents a less appropriate substrate for long diatoms
Classification of chaotic sequences with open-loop estimator - Optimal design for noisy environments
No full textIn this paper, an approach based on ergodic properties for classifying sequences is given. It is particularly robust due to the open loop structure of the detector. Unlike previous works in this direction, such as those concerning the inverse system approach, the detector is not uniquely determined by the transmitter (identical or subsystem thereof), but instead depends on the measurement noise model. The classification is optimized under such imperfect observation conditions. The method is introduced in general for the case of chaotic sequences generated by ergodic maps, and a special case is analyzed in detail to illustrate the method. This specila example resorts to Tchebychev maps and some additional symmetries to make a simple signaling scheme which is low in complexity on both transmitter and receiver sides, while at the same time relatively robust, due to the open-loop structure of the detector.LANO
Special issue on applications of nonlinear dynamics to electronic and information engineering
No full text---
An approach to information propagation in 1-D cellular neural networks-Part I: Local diffusion
No full textThis is the first of two companion papers [1] devoted to a deep analysis of the dynamics of information propagation in the simplest nontrivial Cellular Neural Network (CNN), which is one-dimensional and has connections between nearest neighbors only. We will show that two behaviors are possible: local diffusion of information between neighboring cells and global propagation through the entire array. This paper deals with local diffusion, of which we will first give an accurate definition, before computing the template parameters for which the CNN has this behavior. Next we will compute the number of stable equilibria, before examining the convergence of any trajectory toward them, for three different kinds of boundary conditions: fixed Dirichlet, reflective, and periodic. © 1998 IEEE
Fast and accurate time-domain analysis of piecewise linear dynamic circuits: the computer program PILA
No full textEstimation of Interference Correlation in mmWave Cellular Systems
No full textWe consider a cellular network, where the uplink transmissions to a base station (BS) are interferenced by other devices, a condition that may occur, e.g., in cell-free networks or when using non-orthogonal multiple access (NOMA) techniques. Assuming that the BS treats this interference as additional noise, we focus on the problem of estimating the interference correlation matrix from received signal samples. We consider a BS equipped with multiple antennas and operating in the millimeter-wave (mmWave) bands and propose techniques exploiting the fact that channels comprise only a few reflections at these frequencies. This yields a specific structure of the interference correlation matrix that can be decomposed into three matrices, two rectangular depending on the angle of arrival (AoA) of the interference and the third square with smaller dimensions. We resort to gridless approaches to estimate the AoAs and then project the least square estimate of the interference correlation matrix into a subspace with a smaller dimension, thus reducing the estimation error. Moreover, we derive two simplified estimators, still based on the gridless angle estimation that turns out to be convenient when estimating the interference over a larger number of samples
Automatic methods for motor intention recognition from spike rates
No full textIn this paper we present a method for automatic detection of motor intention from in vivo neuronal recordings in monkeys. The analysis relies on a data base of spike trains collected in a series of experiments aiming to study the hand-eye coordination mechanisms in primates. The neural activity is recorded using a multi-electrode system that can monitor up to fourteen neurons at time. In this work we analyze the possibility to “read” the motor intention from the set of simultaneously recorded spike trains, by combining the information from all the available recordings. We show that the information of interest can be successfully extracted from the data, under some constraints. First, we show the analysis of spike trains, segmented according to the behavioral epochs defined by the experiments protocol, and give the discussion of the proposed method performance in extracting the information of interest, i.e. the presence/absence of motor intention. Also, we consider a less ’controlled’ analysis of entire spike trains, without segmenting, where the relevant information is more mixed with the side-effect processes, and accordingly, more difficult to recognize.LANO
- …
