Search results for " selection"

Pure donation or hybrid donation crowdfunding

2019

PurposeDespite the growing research exploring the possibility and feasibility of financing socially oriented projects through crowdfunding, relatively little research examines which crowdfunding model is better to serve such purpose. The purpose of this paper is to offer novel insights to mitigate this research gap.Design/methodology/approachA unique data set collected from the largest Chinese crowdfunding platform is used to test the hypotheses. To solve the perceived self-selection problem, the propensity score matching method is adopted in this paper. Based on this approach, the results of similar prosocial campaigns in two different models (pure donation and hybrid donation) are compare…

Evolutionary psychology in marketing: Deep, debated, but fancier with fieldwork

2021

Social representations as a diagnostic tool for identifying cultural and other group differences

2005

The aim of this research is to develop a procedure for data collection within a social representations perspective that may be of use in diverse contexts in which investigators wish to understand and compare the norms and values associated with a particular social object in different social or cultural groups. The social representation of sport is studied in two culturally distinct countries, Morocco and France, with the use of an innovative procedure derived from the Model of Basic Cognitive Schemes (Rouquette, 1990, 1994b). The results reveal a difference in the appropriation of values related to sport in the two countries: the social representation of sport for the Moroccans is focused a…

Accelerating Causal Inference and Feature Selection Methods through G-Test Computation Reuse

2021

This article presents a novel and remarkably efficient method of computing the statistical G-test made possible by exploiting a connection with the fundamental elements of information theory: by writing the G statistic as a sum of joint entropy terms, its computation is decomposed into easily reusable partial results with no change in the resulting value. This method greatly improves the efficiency of applications that perform a series of G-tests on permutations of the same features, such as feature selection and causal inference applications because this decomposition allows for an intensive reuse of these partial results. The efficiency of this method is demonstrated by implementing it as…

ℓ1-Penalized Methods in High-Dimensional Gaussian Markov Random Fields

2016

In the last 20 years, we have witnessed the dramatic development of new data acquisition technologies allowing to collect massive amount of data with relatively low cost. is new feature leads Donoho to define the twenty-first century as the century of data. A major characteristic of this modern data set is that the number of measured variables is larger than the sample size; the word high-dimensional data analysis is referred to the statistical methods developed to make inference with this new kind of data. This chapter is devoted to the study of some of the most recent ℓ1-penalized methods proposed in the literature to make sparse inference in a Gaussian Markov random field (GMRF) defined …

Genetic compatibility and sexual selection

2005

In a recent review in TREE [1], Mays and Hill discuss the interface between sexual selection for good genes (i.e. female choice based on traits indicating heritable fitness) and sexual selection for genetic compatibility (i.e. how well the genes of the parents function together in their offspring). We feel that the scope of their contribution is somewhat limited, primarily because they implicitly equate genetic compatibility with genetic dissimilarity. Compatibility does, however, not equal dissimilarity.

Personnalité, stratégies d'approvisionnement et d'appariement chez les Diamants Mandarins (taeniopygia guttata)

2011

In evolutionary biology, phenotypic variation has for a long time been considered as the raw material on which natural selection acts. However, research on the consistency of behaviour led to the development of the animal personality concept during the 1990s. This concept was based on the characterization of traits such as neophobia, aggressiveness, exploratory tendencies and risk-taking behaviour. Since then, several studies have shown that personality can evolve through natural selection and is related to many life-history traits, such as dispersal or anti-predator behaviour.Pairing strategies and foraging strategies are two fundamental components of an organism’s life, but their relation…

Wingless ant males adjust mate-guarding behaviour to the competitive situation in the nest

2011

We investigated whether wingless sexuals of the ant Hypoponera opacior adjust mate-guarding behaviour to the level of competition in the nest. Males mate with young nestmate females shortly before these emerge from the cocoon. Aggressive interactions among adult males have never been observed, but males embrace and guard the cocoons of their mating partners for up to 2 days. In laboratory experiments, the duration of pupal guarding increased with the number of adult males in the nest, but decreased with an increasing number of mating partners per male. These findings demonstrate that males are aware of the competitive situation in the nest and adjust their mating behaviour in an adaptive ma…

Variable selection for the determination of total polar materials in fried oils by near infrared spectroscopy

2018

Total polar materials (TPM) content is considered as the best indicator and the most common parameter to check the quality of deep-frying oils. The development of simpler and quicker analytical techniques than the available methods to monitor oil quality in restaurants and fried food outlets is an important topic related to the human health. This paper reports a comparison of the variable selection of near infrared (NIR) spectra by multiple linear regression (MLR-NIR) with partial least squares (PLS-NIR) models for the quantification of TPM in fried vegetable oils. The use of PLS-NIR offers an alternative in laboratory bench equipment for the determination of TPM in oils employed for fryin…

Sensitivity Maps of the Hilbert-Schmidt Independence Criterion

2018

Abstract Kernel dependence measures yield accurate estimates of nonlinear relations between random variables, and they are also endorsed with solid theoretical properties and convergence rates. Besides, the empirical estimates are easy to compute in closed form just involving linear algebra operations. However, they are hampered by two important problems: the high computational cost involved, as two kernel matrices of the sample size have to be computed and stored, and the interpretability of the measure, which remains hidden behind the implicit feature map. We here address these two issues. We introduce the sensitivity maps (SMs) for the Hilbert–Schmidt independence criterion (HSIC). Sensi…