When overconfident traders meet feedback traders

In this paper, we develop a model in which overconfident market participants and rational speculators trade against trend-chasers. We exhibit the unique linear equilibrium and assess the quality of prices according to the proportion of the different types of agents. We highlight how speculative bubbles arise when a large number of traders adopt a trend-chasing behavior. We show that overconfident traders can obtain positive expected profits. In particular, over-confident traders can outperform rational traders. The positive feedback trading enhances the negative correlation between the back-to-back prices changes and the volatility of prices as well. We show that positive feedback traders destabilize prices more than their overconfident opponents. Generally, overconfidence increases the volatility of prices and worsens the market efficiency. But, we show that in the presence of positive feedback trading, overconfidence improves the market efficiency and dampens the excess volatility

Живучесть интеллектуальных систем управления, созданных на базе рецепторно-эффекторных нейроподобных растущих сетей

В статье рассмотрены вопросы надежности распознавания образов и живучести систем искусственного интеллекта, разработанных на базе рецепторно-эффекторных нейроподобных растущих сетей. Нейроподобные растущие структуры работают с высокой надежностью и обеспечивают живучесть интеллектуальных систем. Эксперименты, проведенные на моделях интеллектуальных систем, показывают, что выход из строя большого количества элементов нейроподобной сети не приводит к отказам в работе всей системы.У статті розглянуті питання надійності розпізнавання образів і живучості систем штучного інтелекту, розроблених на базі рецепторно-ефекторних нейроподібних зростаючих мереж. Нейроподібні зростаючі структури працюють з високою надійністю і забезпечують живучість інтелектуальних систем. Експерименти, проведені на моделях інтелектуальних систем, показують, що вихід з ладу великої кількості елементів нейроподібної мережі не приводить до відмов у роботі всієї системи.The questions of reliability of pattern recognition and artificial intelligence systems survivability developed on the basis of receptor-effector neural growing networks were regarded. Growing neural structures operate with a high reliability and ensure survivability of intelligent systems. Experiments conducted on the models of intelligent systems show that the failure of a large number of neural network elements does not lead to failures in the system

When Overconfident Traders Meet Feedback Traders

We develop a model in which informed overconfident market participants and informed rational speculators trade against trend-chasers. In this model positive feedback traders act as Computer Based Trading (CBT) and lead to positive feedback loops. In line with empirical findings we find a positive relationship between the volatility of prices and the size of the price reversal. The presence of positive feedback traders leads to a higher degree of trading activity by both types of informed traders. Overconfidence can lead to less price volatility and more efficient prices. Moreover, overconfident traders may be better off than their rational counterparts

Heterogeneous Noisy Beliefs and Dynamic Competition in Financial Markets

This paper analyzes the competition of heterogeneously informed traders in a multi-auction setting. We obtain that the competition can take different forms depending on the number of traders, trading rounds and the noise in the information. When the number of traders is small and the number of trading rounds is large, traders may trade very aggressively at the opening and at the end of the trading day with lower trading intensity in between. Hence, we can explain volume patterns by the nature of the competition between traders rather than by pattern in the level of liquidity. We find that the noise in the signal may be beneficial for traders when the competition is strong as it gives them a monopolistic position on their private information. The amount of noise maximizing the trader’s expected profit increases with the number of trading rounds as well as the number of traders. This implies that the value of information is closely related to the market where that information is subsequently being used

When Overconfident Traders Meet Feedback Traders

We develop a model in which informed overconfident market participants and informed rational speculators trade against trend-chasers. In this model positive feedback traders act as Computer Based Trading (CBT) and lead to positive feedback loops. In line with empirical findings we find a positive relationship between the volatility of prices and the size of the price reversal. The presence of positive feedback traders leads to a higher degree of trading activity by both types of informed traders. Overconfidence can lead to less price volatility and more efficient prices. Moreover, overconfident traders may be better off than their rational counterparts

CFD-based functional imaging for arteries: in vitro validation

De l’imagerie fonctionnelle pour les vaisseaux est développée à partir de données médicales morphologiques (IRM 4D) et hémodynamiques (IRM par contraste de phase dans les plans d’entrée-sortie). Les données fonctionnelles pertinentes (champ de vitesse, frottement pariétal, gradient de pression,…) sont alors calculées en simulant l’écoulement compatible avec les données médicales. On présente les résultats obtenus dans la phase de validation in vitro de cette technique sur un fantôme de crosse aortique

Combining Bayesian and Deep Learning Methods for the Delineation of the Fan in Ultrasound Images

Ultrasound (US) images usually contain identifying information outside the ultrasound fan area and manual annotations placed by the sonographers during exams. For those images to be exploitable in a Deep Learning framework, one needs to first delineate the border of the fan which delimits the ultrasound fan area and then remove other annotations inside. We propose a parametric probabilistic approach for the first task. We make use of this method to generate a training data set with segmentation masks of the region of interest (ROI) and train a U-Net to perform the same task in a supervised way, thus considerably reducing computational time of the method, one hundred and sixty times faster. These images are then processed with existing inpainting methods to remove annotations present inside the fan area. To the best of our knowledge, this is the first parametric approach to quickly detect the fan in an ultrasound image without any other information than the image itself

Politicas agrarias y estrategias campesinas en la Cuenca del Canete : anexos 8 a 13

Ce document réunit plusieurs diagnostics établis à partir d'observations de terrain sur la géographie physique, l'organisation sociale, les pratiques paysannes dans la vallée de Canete et la vallée Pampas afin de déterminer les facteurs limitants de la production et des pratiques culturales , notamment en matière d'irrigation

Far-and mid-infrared properties of carbon layers elaborated by plasma sputtering

International audienceThe far-and mid-infrared reflectivity spectra of two carbon layers deposited on pure (100) silicon substrates by DC magnetron sputtering were investigated at room temperature in the 10-5000 cm-1 wavenumber range. Their structural and textural features were also studied by combining Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray Reflectivity (XRR) and Rutherford Backscattering Spectroscopy (RBS). The set of results was used to discuss afterwards the influence of the texture on the infrared properties at varying length scale. Thereby, the two layers were found to be heterogeneous as assessed by RBS, XRR and FESEM and their thicknesses had been measured by XRR and FESEM. The information on the structural organization and " crystallite " size was given by Raman spectroscopy. The influence of both the textural and structural parameters on the measured infrared reflectivity spectra was discussed. Finally, a methodology was proposed to recover the intrinsic index of refraction and the intrinsic index of absorption of each layer