Fair Learning to Rank with Distribution-free Risk Control

Learning to Rank (LTR) methods are vital in online economies, affecting users and item providers. Fairness in LTR models is crucial to allocate exposure proportionally to item relevance. The deterministic ranking model can lead to unfair exposure distribution when items with the same relevance receive slightly different scores. Stochastic LTR models, incorporating the Plackett-Luce (PL) model, address fairness issues but have limitations in computational cost and performance guarantees. To overcome these limitations, we propose FairLTR-RC, a novel post-hoc model-agnostic method. FairLTR-RC leverages a pretrained scoring function to create a stochastic LTR model, eliminating the need for expensive training. Furthermore, FairLTR-RC provides finite-sample guarantees on a user-specified utility using distribution-free risk control framework. By additionally incorporating the Thresholded PL (TPL) model, we are able to achieve an effective trade-off between utility and fairness. Experimental results on several benchmark datasets demonstrate that FairLTR-RC significantly improves fairness in widely-used deterministic LTR models while guaranteeing a specified level of utility.Comment: 13 pages, 4 figure

Cost-benefit analysis of mass vaccination campaign against H5N1 in small scale production systems in Vietnam. Part I: Economical results in Long An province

Highly Pathogenic Avian Influenza (HPAI) caused by H5N1 virus has become endemic in some developing countries and millions of birds have been culled with large economical and sociological impacts. Since the end of the first vaccination campaign in Vietnam limited outbreaks in non-vaccinated domestic poultry have been reported. However, the virus is still circulating as confirmed by routine surveillance programs. Vaccination is a useful tool to be used to eradicate the disease, but the cost-benefit impact of different strategy needs first to be addressed at local level, where implementation is decided. The aim of this study was to evaluate the cost-benefit impact of Vietnam mass vaccination program at local level. This poster presents the first step in the cost-benefit analysis: the partial economical analysis of the vaccination within Vietnam provinces. Only the results in Long An province (South) are presented here

Fair Classifiers that Abstain without Harm

In critical applications, it is vital for classifiers to defer decision-making to humans. We propose a post-hoc method that makes existing classifiers selectively abstain from predicting certain samples. Our abstaining classifier is incentivized to maintain the original accuracy for each sub-population (i.e. no harm) while achieving a set of group fairness definitions to a user specified degree. To this end, we design an Integer Programming (IP) procedure that assigns abstention decisions for each training sample to satisfy a set of constraints. To generalize the abstaining decisions to test samples, we then train a surrogate model to learn the abstaining decisions based on the IP solutions in an end-to-end manner. We analyze the feasibility of the IP procedure to determine the possible abstention rate for different levels of unfairness tolerance and accuracy constraint for achieving no harm. To the best of our knowledge, this work is the first to identify the theoretical relationships between the constraint parameters and the required abstention rate. Our theoretical results are important since a high abstention rate is often infeasible in practice due to a lack of human resources. Our framework outperforms existing methods in terms of fairness disparity without sacrificing accuracy at similar abstention rates

Relation between the poultry production systems and the Highly Pathogenic Avian Influenza (HPAI) in Vietnam

In 2003, the poultry population was about 254.6 millions heads. The poultry herd is mainly concentrated in the Red River Delta (RRD) and in the Mekong Delta with about 50% of poultry population. The Highly Pathogenic Avian Influenza caused by H5N1 virus was removed in almost of provinces in Vietnam from 2004 until now but millions of birds were culled to reach this situation and it had large economical and sociological impacts. A question emerge: how can we limit this epidemic? A research on the relation between poultry production systems and the HPAI had been carried out in two provinces: Ha Tay (RRD) and Long An (Mekong Delta) from March to August 2007. The results showed that there are three principal poultry production systems which are commercial poultry production systems with good breeding facilities (system 1); commercial poultry production systems without good breeding facilities (system 2), and small scale poultry production system (system 3). The number of birds reared in the commercial systems was more important than that of the small system, conversely the number of species rising in the system 2 and 3 was more important than in the system 1. The proportion of households having poultry herd with HPAI in the period of 2003-2005 in the system 2 and 3 were more important than that of the system 1 (21-59% compare with 33-36%). The study had showed that all poultry belonging to the system 1 were vaccinated; when the proportion of vaccinated animals were about 87-90% for the system 2, and 58% for the system 3

Characteristics of poultry production systems and cost-benefit analysis of mass vaccination campaign against HPAI in poultry production systems in Long An Province, South Vietnam

peer reviewedIn 2006, the poultry population of Vietnam was about 215 million heads. However, between 2004 and 2008, the Highly Pathogenic Avian Influenza (HPAI) caused by H5N1 virus was broken in affected almost all provinces in Vietnam with millions of birds culled. This had large economical and sociological impacts. A question has been raised: how could Vietnam limit this epidemic? The research aims to identify the poultry production systems with their various constraints, including diseases and to evaluate the cost-benefit impact of a mass vaccination programme implemented from March to August 2007 at local level in Long An Province within the Mekong Delta. Two principal poultry farming systems are characterised: the commercial poultry production system (system 1) with low to moderate bio-security level, and the small-scale production system (system 2) with a low bio-security level. The scenarios of cost-benefit analysis of vaccination campaigns against HAPI caused by H5N1 virus give a good strategy for the restructure of poultry production and farmers’ incentives to vaccinate. The vaccination is more cost effective for the farmer than culling operations, with the BCR scenarios are between 31 to 78 times more.HPA

Relation between the poultry production systems and HPAI and response of peasant with epidemic disease on poultry flock in Vietnam

peer reviewedCosts-benefit of avian influenza vaccinatio

Improving retrieval framework using information gain models

International audienceContent-based image retrieval systems are meant to retrieve the most similar images of a collection to a query image. One of the most well-known models widely applied for this task is the bag of visual words (BoVW) model. In this paper, we introduce a study of different information gain models used for the construction of a visual vocabulary. In the proposed framework, information gain models are used as a discriminative information to index image features and select the ones that have the highest information gain values. We introduce some extensions to further improve the performance of the proposed framework: mixing different vocabularies and extending the BoVW to bag of visual phrases. Exhaustive experiments show the interest of information gain models on our retrieval framework

Poly(lactic acid)/carbon nanotube nanocomposites with integrated degradation sensing

International audienc

Knr4 N-terminal domain controls its localization and function during sexual differentiation and vegetative growth

International audienceThe Saccharomyces cerevisiae protein Knr4 is composed of a globular central core flanked by two natively disordered regions. Although the central part of the protein holds most of its biological function, the N-terminal domain (amino acids 1-80) is essential in the absence of a functional CWI pathway. We show that this specific protein domain is required for the proper cellular localization of Knr4 at sites of polarized growth during vegetative growth and sexual differentiation (bud tip and 'shmoo' tip). Moreover, Knr4 N-terminal domain is also necessary for cell cycle arrest and shmoo formation in response to pheromone to occur at the correct speed. Thus, the presence of Knr4 at the incipient mating projection site seems important for the establishment of the following polarized growth. Cell wall integrity (CWI) and calcineurin pathways are known to share a common essential function, for which they can substitute for one another. Searching for Knr4 partners responsible for survival in a CWI-defective background, we found that the catalytic subunit of calcineurin Cna1 physically interacts with Knr4 in the yeast two-hybrid assay, in a manner dependent on the presence of the Knr4 N-terminal domain. In addition, we present evidence that Knr4 protein participates in the morphogenesis checkpoint, a safety mechanism that holds the cell cycle in response to bud formation defects or insults in cytoskeleton organization, and in which both the CWI pathway and calcineurin are involved