Word sense disambiguation criteria: a systematic study

This article describes the results of a systematic in-depth study of the criteria used for word sense disambiguation. Our study is based on 60 target words: 20 nouns, 20 adjectives and 20 verbs. Our results are not always in line with some practices in the field. For example, we show that omitting non-content words decreases performance and that bigrams yield better results than unigrams

Issues and Challenges of Measurement of Health:Implications for Economic Research

According to the human capital theory, health is a determinant of the economic development and should play a role in the fight against poverty. On the other side, the economic growth, by supplying better sanitation, water quality and hygiene, better education and income, may improve population's health. Economists, in investigating the relations between development and health, asked for valid and relevant health status measurement. But, on the other hand, the health concept is complex as health includes several dimensions, and researchers face a battery of health indicators. The purpose of this study is to discuss, specifically for economic research, the particularity of each health indicator, the potential bias of their measurement, their advantages, disadvantages, and interest. As health indicators are too numerous, a selection was done and the analysis concerns the most frequent indicators, but also those which should be more used into the economic research perspective. Discussed health indicators are life expectancy and healthy life expectancy at birth, mortality rates (maternal and infant mortality included), cause-specific morbidity rates, Dalys and Qalys.cerdi

Endemic diseases and agricultural productivity: Challenges and policy response

Contrary to Asian countries, the agricultural sector in Africa had not benefited from the green revolution success. After a long time of disinterest in the agriculture sector in Africa, several voices arise now in favour of greater efforts towards this sector. Several studies tend to show the crucial role of agriculture in African countries' growth and highlight the huge need of increasing the productivity in this sector. If increase in agriculture productivity requires both an expansion of irrigated areas and the adoption of high yield varieties, those innovations and their high development could be the source of negative health (and environmental) effects. Using a mega-analysis, this paper highlights first the links between health, disease and development and then agricultural productivity. The literature review shows that the negative effect of bad health was not systematically checked, and that the intensity of this effect depends of the disease, but also of the work productivity and the existence or not of a coping process. The second part of the paper focused on the development of high intensive agriculture as a risk factor for farmers' and rural inhabitants' health. This survey shows that whether irrigation and fertilizer and pest intensive use could be considered as highly health (and environmental) risk factors, appropriate control measures (such as for examples systematic maintenance of irrigation canals, alternate wetting and drying of irrigated fields or integrated pest management) considerably reduce this risk, while at the same time, increase the agriculture productivity.agriculture;productivity;endemic disease;health risk factor;Africa

Endemic diseases and agricultural productivity: Challenges and policy response

Contrary to Asian countries, the agricultural sector in Africa had not benefited from the green revolution success. After a long time of disinterest in the agriculture sector in Africa, several voices arise now in favour of greater efforts towards this sector. Several studies tend to show the crucial role of agriculture in African countries’ growth and highlight the huge need of increasing the productivity in this sector. If increase in agriculture productivity requires both an expansion of irrigated areas and the adoption of high yield varieties, those innovations and their high development could be the source of negative health (and environmental) effects. Using a mega-analysis, this paper highlights first the links between health, disease and development and then agricultural productivity. The literature review shows that the negative effect of bad health was not systematically checked, and that the intensity of this effect depends of the disease, but also of the work productivity and the existence or not of a coping process. The second part of the paper focused on the development of high intensive agriculture as a risk factor for farmers’ and rural inhabitants’ health. This survey shows that whether irrigation and fertilizer and pest intensive use could be considered as highly health (and environmental) risk factors, appropriate control measures (such as for examples systematic maintenance of irrigation canals, alternate wetting and drying of irrigated fields or integrated pest management) considerably reduce this risk, while at the same time, increase the agriculture productivity.agriculture, productivity, endemic disease, health risk factor, Africa

Robustness of Anytime Bandit Policies

This paper studies the deviations of the regret in a stochastic multi-armed bandit problem. When the total number of plays n is known beforehand by the agent, Audibert et al. (2009) exhibit a policy such that with probability at least 1-1/n, the regret of the policy is of order log(n). They have also shown that such a property is not shared by the popular ucb1 policy of Auer et al. (2002). This work first answers an open question: it extends this negative result to any anytime policy. The second contribution of this paper is to design anytime robust policies for specific multi-armed bandit problems in which some restrictions are put on the set of possible distributions of the different arms

Fast learning rates for plug-in classifiers under the margin condition

It has been recently shown that, under the margin (or low noise) assumption, there exist classifiers attaining fast rates of convergence of the excess Bayes risk, i.e., the rates faster than $n^{-1/2}$. The works on this subject suggested the following two conjectures: (i) the best achievable fast rate is of the order $n^{-1}$, and (ii) the plug-in classifiers generally converge slower than the classifiers based on empirical risk minimization. We show that both conjectures are not correct. In particular, we construct plug-in classifiers that can achieve not only the fast, but also the {\it super-fast} rates, i.e., the rates faster than $n^{-1}$. We establish minimax lower bounds showing that the obtained rates cannot be improved.Comment: 36 page

Issues and Challenges of Measurement of Health:Implications for Economic Research

According to the human capital theory, health is a determinant of the economic development and should play a role in the fight against poverty. On the other side, the economic growth, by supplying better sanitation, water quality and hygiene, better education and income, may improve population’s health. Economists, in investigating the relations between development and health, asked for valid and relevant health status measurement. But, on the other hand, the health concept is complex as health includes several dimensions, and researchers face a battery of health indicators. The purpose of this study is to discuss, specifically for economic research, the particularity of each health indicator, the potential bias of their measurement, their advantages, disadvantages, and interest. As health indicators are too numerous, a selection was done and the analysis concerns the most frequent indicators, but also those which should be more used into the economic research perspective. Discussed health indicators are life expectancy and healthy life expectancy at birth, mortality rates (maternal and infant mortality included), cause-specific morbidity rates, Dalys and Qalys.

No fast exponential deviation inequalities for the progressive mixture rule

We consider the learning task consisting in predicting as well as the best function in a finite reference set G up to the smallest possible additive term. If R(g) denotes the generalization error of a prediction function g, under reasonable assumptions on the loss function (typically satisfied by the least square loss when the output is bounded), it is known that the progressive mixture rule g_n satisfies E R(g_n) < min_{g in G} R(g) + C (log|G|)/n where n denotes the size of the training set, E denotes the expectation w.r.t. the training set distribution and C denotes a positive constant. This work mainly shows that for any training set size n, there exist a>0, a reference set G and a probability distribution generating the data such that with probability at least a R(g_n) > min_{g in G} R(g) + c sqrt{[log(|G|/a)]/n}, where c is a positive constant. In other words, surprisingly, for appropriate reference set G, the deviation convergence rate of the progressive mixture rule is only of order 1/sqrt{n} while its expectation convergence rate is of order 1/n. The same conclusion holds for the progressive indirect mixture rule. This work also emphasizes on the suboptimality of algorithms based on penalized empirical risk minimization on G

Regret lower bounds and extended Upper Confidence Bounds policies in stochastic multi-armed bandit problem

This paper is devoted to regret lower bounds in the classical model of stochastic multi-armed bandit. A well-known result of Lai and Robbins, which has then been extended by Burnetas and Katehakis, has established the presence of a logarithmic bound for all consistent policies. We relax the notion of consistence, and exhibit a generalisation of the logarithmic bound. We also show the non existence of logarithmic bound in the general case of Hannan consistency. To get these results, we study variants of popular Upper Confidence Bounds (ucb) policies. As a by-product, we prove that it is impossible to design an adaptive policy that would select the best of two algorithms by taking advantage of the properties of the environment

Income Growth, Price Variation and Health Care Demand: A Mixed Logit Model Applied to Tow-period Comparison in Rural China

1989-2006 is a period of the start and the end of deregulation of Chinese health care sector and of disintegration of rural cooperative insurance system. During this period, the government health policy has turned healthcare providers all alike into profit seeking entities. Face to perverse effects, by 2003, Chinese government begun to restore rural cooperative insurance system. From CHNS data source, we constitute two samples: 89-93 and 04-06 with respectively 2117 and 2594 rural patients surveyed roughly in the same villages in 9 Chinese provinces to compare their health choice behaviors with the evolution of price, income, distance, insurance, age, and regional inequality. Using Mixed Multinomial Logit (MMNL) estimations, we have obtained three main results. First, even in both periods there is clear price effect, in 04-06 it tends to be weaker, and heterogeneity in price preference has increased. This corresponds well the fact that between the two periods price level has significantly increased and price variation reduced. Second, there is a stronger negative distance effect and heterogeneity in 2004-06, while in 89-93 this negative impact was lower and absent for providers farther than 10km. One interpretation is the existence of a substitution effect: when patients have less possibility to discriminate providers by price, they increase their preference in choice by distance. Third, while, wealth effect exists in some choices in 89-93, it becomes absent in 04-06. Explanations may be that one the one hand both supply side and demand side conditions on health care have been improved even, to less extent though, for the poor, and on the other hand, health care is necessary goods and is price inelastic. But meanwhile, we observed catastrophic effect for the poor: the poorer patients have their share of consumption in income more decreased after health care.Empirical approach;health care demand;mixed logit model;insurance;China