On uniqueness for a rough transport-diffusion equation

In this Note, we study a transport-diffusion equation with rough coefficients and we prove that solutions are unique in a low-regularity class

Sur l'unicité pour une équation de transport-diffusion irrégulière.

International audienceIn this Note, we study a transport-diffusion equation with rough coefficients and we prove that solutions are unique in a low-regularity class.Dans cette Note, nous étudions une équation de transport-diffusion a coefficients irréguliers et nous prouvons l'unicité de sa solution dans une classe de fonctions peu régulières

On-the-job learning and earnings

A simple model of informal learning on-the-job which combines learning by oneself and learning from others is proposed in this paper. It yields a closed-form solution that revises Mincer-Jovanovic's (1981) treatment of tenure in the human capital earnings function by relating earnings to the individual's learning potential from jobs and firms. We estimate the structural parameters of this non-linear model on a large French survey with matched employer-employee data. We find that workers on average can learn from others ten percent of their own human capital on entering the firm, and catch half of their learning potential in just two years. The measurement of worker's learning potential in their jobs and establishments provides a simple characterization of primary-type and secondary-type jobs and establishments. We find a strong relationship between the job-specific learning potential and tenure. Predictions of dual labor market theory regarding the positive match of primary-type firms (which offer high learning opportunities) with highly endowed workers (educated, high wages) are visible at the establishment level but seem to vanish at the job's level.Human capital, earnings functions, informal training, learning from others, learning by oneself, returns to tenure, dualism.

On-the-job learning and earnings

URL des Cahiers : https://halshs.archives-ouvertes.fr/CAHIERS-MSECahiers de la MSE 2005.22 - Série Blanche - ISSN : 1624-0340A simple model of informal learning on-the-job which combines learning by oneself and learning from others is proposed in this paper. It yields a closed-form solution that revises Mincer-Jovanovic's (1981) treatment of tenure in the human capital earnings function by relating earnings to the individual's learning potential from jobs and firms. We estimate the structural parameters of this non-linear model on a large French survey with matched employer-employee data. We find that workers on average can learn from others ten percent of their own human capital on entering the firm, and catch half of their learning potential in just two years. The measurement of worker's learning potential in their jobs and establishments provides a simple characterization of primary-type and secondary-type jobs and establishments. We find a strong relationship between the job-specific learning potential and tenure. Predictions of dual labor market theory regarding the positive match of primary-type firms (which offer high learning opportunities) with highly endowed workers (educated, high wages) are visible at the establishment level but seem to vanish at the job's level.Nous proposons un modèle d'apprentissage informel qui identifie deux des principales composantes de la formation en entreprise : l'apprentissage autonome et l'apprentissage par observation des autres. En reliant les gains au potentiel d'apprentissage dans l'entreprise, celui-ci révise la modélisation classique de l'ancienneté (Mincer et Jovanovic, 1981). L'estimation des paramètres structurels de ce modèle non-linéaire, à l'aide de données appariées françaises, fait apparaître, qu'en moyenne, les salariés peuvent apprendre l'équivalent de dix pour cent de leur capital humain initial et qu'il leur faut deux ans pour acquérir la moitié de ce potentiel d'apprentissage. Le potentiel d'apprentissage des individus dans leur établissement permet, à la fois au niveau des emplois et des établissements, de distinguer un secteur primaire (à forte accumulation en capital humain) d'un secteur secondaire (à faible accumulation en capital humain). Nous montrons qu'il existe une forte corrélation entre le potentiel d'apprentissage et l'ancienneté. Les prédictions de la théorie duale du marché du travail concernant l'appariement positif entre secteur primaire et salariés les plus éduqués, visibles au niveau des établissements, semble disparaître au niveau des emplois

Learning from experience or learning from others? Inferring informal training from a human capital earnings function with matched employer–employee data

A model of informal training which combines learning from own experience and learning from others is proposed in this paper. It yields a closed-form solution that revises Mincer–Jovanovic's [Mincer, J., Jovanovic, B., 1981. Labor mobility and wages. In: Rosen, S. (Ed.), Studies in Labor Markets. Chicago University Press, Chicago, pp. 21–64] treatment of tenure in the human capital earnings function. We estimate the structural parameters of this non-linear model on a large French cross-section with matched employer–employee data. We find that workers on average can learn from others 10% of their own human capital on entering one plant, and catch half of their learning from others' potential in just 2 years. The private marginal returns to education are declining with education as more educated workers have less to learn from others and share the social returns of their own education with their less qualified co-workers. The potential for learning from others on the job varies across jobs and establishments, and this provides a new distinction between imitation jobs and experience jobs. Workers in imitation jobs, who learn most from others, tend to have considerably longer tenure than workers in experience jobs. Although workers in experience jobs can learn little from others, we find that they learn a lot by themselves. We document several analogies between the imitation jobs/experience jobs “dualism” and the primary/secondary jobs and firms' dualism implied by the dual labor market theory. However, our binary classification of jobs depicts the data more closely than the dual theory categorization into primary-type and secondary-type establishments. Competition prevails between jobs and firms but jobs differ by their learning technology.Human capital earnings functions; Matched employer–employee data; Informal training; Learning from others; Learning from experience; Returns to tenure; Social returns of education; Labor market dualism

Magnetic dephasing in mesoscopic spin glasses

We have measured Universal Conductance Fluctuations in the metallic spin glass Ag:Mn as a function of temperature and magnetic field. From this measurement, we can access the phase coherence time of the electrons in the spin glass. We show that this phase coherence time increases with both the inverse of the temperature and the magnetic field. From this we deduce that decoherence mechanisms are still active even deep in the spin glass phase

Power Consumption Optimization in Multi-mode Mobile Relay

International audienceMulti-mode is a common feature in current generation terminals, enabling the user to stay connected at any time. By selecting an appropriate standard, multi-mode can reduce terminal power consumption. Software Defined Radio is an enabler towards multi-mode for the next generation of terminals. In such a radio, communication modes are implemented by a general processor through digital functions, instead of dedicated chips. Providing access to users in bad conditions through relays, is another solution to reduce power consumption. We look at multi-mode relaying, where a mobile terminal, connected to an UMTS base station, acts as an 802.11g-relay for those users. In this paper, we evaluate the algorithmic complexity of 802.11g and UMTS to estimate the power consumption of a Software Defined Radio. We propose a multi-mode relay scheme using such terminals, with the purpose of minimizing the global power consumption. Finally, we enounce different rules to maximize the local and global power gain by implementing multi-mode relays

Hastings' additivity counterexample via Dvoretzky's theorem

The goal of this note is to show that Hastings' counterexample to the additivity of minimal output von Neumann entropy can be readily deduced from a sharp version of Dvoretzky's theorem on almost spherical sections of convex bodies.Comment: 12 pages; v.2: added references, Appendix A expanded to make the paper essentially self-containe

Multi-mode relaying for energy consumption reduction

Today mobile terminals offer today the possibility of switching between different physical layers of radio protocols. With a generalization of Software Defined Radio, this multi-mode property improves the connectivity but has an important cost in terms of energy consumption. In this paper, we study the possibility of reducing energy consumption by using a relay on possibly different communication modes. We show that a multi-mode relay, compared to simple (mono-mode) relay, has an impact on energy consumption. We propose an analytical study of energy consumption in multi-mode terminals. Then, we will compare the network energy consumption following two scenarios: in the first one, a mobile terminal relays other users, in the second one terminals connect directly to an Access Point. We evaluate the consumption of the terminals in an 802.11g-to-UMTS and an 802.15.4-to-802.11g relay scheme. We isolate rules to minimize the network global energy consumption through multi-mode relaying. We show that the most intuitive solution is not always the best one and that a very precise simulation is necessary to make good choices at run time.Aujourd'hui, les terminaux mobiles permettent de choisir parmi différentes couches physiques de protocoles radios. Avec la généralisation de la Radio Logicielle, cette propriété multi-mode améliore la connectivité, mais rajoute un important surcoût à la consommation d'énergie. Dans ce papier, nous étudions la possibilité de réduire la consommation d'énergie en proposant un relais peut communiquer sur ces différents modes. Nous montrons qu'un relais multi-mode a un impact sur la consommation d'énergie, en comparaison à un simple relais mono-mode. Nous proposons une étude analytique de la consommation d'énergie pour les terminaux multi-modes. Puis, nous comparons la comsommation d'énergie du réseau suivant deux scénarios: dans le premier, un terminal mobile joue le rôle de relais pour d'autres utilisateurs ; dans le second, tous les terminaux se connectent directement au point d'accès. Nous évaluons la consommation des terminaux dans des scénarios de relais 802.11g-vers-UMTS et 802.15.4-vers-802.11g. Nous isolons des règles qui permettent de minimiser la consommation global du réseau au travers des relais multi-modes. Nous montrons que la solution la plus intuitive n'est pas toujours la meilleure, et qu'une évaluation précise au travers de simulations est nécessaire afin de procéder à un bon choix de paramètres