An iterated greedy algorithm for the flowshop scheduling problem with blocking

This paper proposes an iterated greedy algorithm for solving the blocking flowshop scheduling problem for makespan minimization. Moreover, it presents an improved NEH-based heuristic, which is used as the initial solution procedure for the iterated greedy algorithm. The effectiveness of both procedures was tested on some of Taillard’s benchmark instances that are considered to be blocking flowshop instances. The experimental evaluation showed the efficiency of the proposed algorithm, in spite of its simple structure, in comparison with a state-of-the-art algorithm. In addition, new best solutions for Taillard’s instances are reported for this problem, which can be used as a basis of comparison in future studies.     

Irregular employment amongst migrants in Spanish cities

This article presents the irregular employment situation of non-European union immigrants in Spanish cities. Foreign labor is remarkable for its heterogeneity in terms of country of origin, demographic characteristics, and the different ways in which immigrants have entered the job market. Legal immigrants tend to concentrate in five different branches of activity, such as domestic service (mostly women), hotel and restaurant industry, agriculture, building and retail trade. Migrants who work in agriculture suffer the worst labor conditions than all other migrants. However, all migrants experience difficulty in obtaining residency and labor permits. Four integration strategies among Moroccan immigrants in Catalonia are discussed and can be viewed as support networks of the immigrants.