How the structure of precedence constraints may change the complexity class of scheduling problems

This survey aims at demonstrating that the structure of precedence constraints plays a tremendous role on the complexity of scheduling problems. Indeed many problems can be NP-hard when considering general precedence constraints, while they become polynomially solvable for particular precedence constraints. We also show that there still are many very exciting challenges in this research area

New complexity results for parallel identical machine scheduling problems with preemption, release dates and regular criteria

In this paper, we are interested in parallel identical machine scheduling problems with preemption and release dates in case of a regular criterion to be minimized. We show that solutions having a permutation flow shop structure are dominant if there exists an optimal solution with completion times scheduled in the same order as the release dates, or if there is no release date. We also prove that, for a subclass of these problems, the completion times of all jobs can be ordered in an optimal solution. Using these two results, we provide new results on polynomially solvable problems and hence refine the boundary between P and NP for these problems

Correlations between cancellous bone architecture and its dynamic behaviour

Previous studies showed that in vivo evaluation of the fracture risk of cancellous bone can be assessed by identifying the relationships between its microarchitecture description extracted from clinical imaging and its mechanical properties. The mechanical properties under dynamic loadings (with and without confinement) were obtained and compared to quasi-static ones. The architectural parameters of each specimen were extracted from pQCT images and split into four groups: geometry, topology, connectivity and anisotropy. Results show that architectural parameters are strong determinants of mechanical behaviour for the different applied boundary conditions.http://icills2014.org/wp-content/uploads/2014/01/Marrianne-Prot.pd

Science denial as intergroup conflict: using social identity theory, intergroup emotions theory and intergroup threat theory to explain angry denial of science

Denial of scientific evidence is a fairly common phenomenon which has been documented in various areas such as climate change, evolution, effects of vaccinations, tobacco and violent video game effects. Science denial is often accompanied by anger and aggressive actions towards scientists, leading some authors to label it war on science (Lewandowsky, Oberauer & Gignac, 2013). Science denial can be explained, in part, by well-established processes affecting individuals such as belief perseverance, confirmation bias and cognitive dissonance. However, recent research suggests that group processes may also play a key role in denial (Lewandowsky et al., 2013; Nauroth et al., 2014). The current research takes this reasoning a step further and frames science denial in terms of intergroup conflict. I propose that the relationship between denialists and scientists can be understood in terms of intergroup relations (scientists are viewed as a hostile outgroup). Three sets of studies applied principles of social identity theory (Study 1A, 1B, 1C), intergroup threat theory (Study 2A, 2B, 2C) and intergroup emotions theory (Study 3) to explore the mechanisms that lead to science denial. Special attention is given to predictors of angry denial and aggressive actions towards scientists

Intermediate strain rate behavior of cancellous bone: From the lower to the higher strain rate

Not applicabl