Management of the operations in a copper smelter is fundamental for optimizing the use of the plant's installed capacity. In the refining and casting stage, the operations are particularly complex due to the metallurgical characteristics of the process. This paper tackles the problem of automatic scheduling of operations in the refining and casting stage of a copper concentrate smelter. The problem is transformed into a flexible flow shop problem and to solve it, an iterative method is proposed that operates in two stages: in the first stage, a sequence of jobs is constructed that configures the lots, and in the second, the constructed solution is improved by means of simulated annealing. Fifteen test problems are used to show that the proposed algorithm improves the makespan by an average of 9.42% and the mean flow time by 12.19% with respect to an existing constructive heuristic.

Resumen El artículo resalta la importancia de la investigación criminal para el esclarecimiento de hechos punibles y su contribución a la administración de justicia. En Colombia, los lineamientos para investigar delitos están consignados en el Código de Procedimiento Penal (Ley 906 de 2004) y como complemento, la Policía Nacional establece los protocolos para llevar a cabo este tipo de investigaciones que junto con el apoyo técnico científico y el conocimiento de los investigadores permiten identificar, individualizar y judicializar los presuntos autores de un delito. Finalmente, el artículo desarrolla un caso de la vida real para evidenciar la efectividad de la investigación criminal.

Abstract This paper highlights the relevance of Criminal Investigation in order to clear up crimes and its contribution to law enforcement. In Colombia, guidelines to investigate crimes are set out in the Penal Code (Act 906/2004), and as a complement, the National Police sets up protocols to carry out such type of investigations that, together with the investigators` technical-scientific knowledge would permit the identification, determination and proper prosecution of alleged crime perpetrators. Finally, this paper presents a real-life case to demonstrate the efficiency of criminal investigation.

This article analyzes the impact of political activism by Mexican migrants living in the United States who seek to exercise their political rights in Mexico. The factors that are creating conditions in Mexico needed to put into effect fundamental citizen rights, such as the vote in presidential elections and representation in the legislative branch for citizens living abroad, are analyzed. The opening of the Mexican political system to the international migrants is attributed to a convergence of processes that include the incipient transition to democracy, the institutionalization of the relationship between migrants and political parties, and the activism of the migrants themselves, as they seek to promote electoral reforms and policies related to their social condition.

En este artículo se estudia el impacto del activismo político de los migrantes mexicanos residentes en los Estados Unidos que buscan ejercer sus derechos políticos en México. Se analizan los factores que están creando las condiciones en México para hacer efectivos derechos ciudadanos fundamentales como el voto en elecciones presidenciales y la representación en el Poder Legislativo para ciudadanos en el exterior. La apertura del sistema político mexicano a los migrantes internacionales se atribuye a una convergencia de procesos, que incluyen la incipiente transición a la democracia, la institucionalización de la relación entre migrantes y partidos políticos y el activismo de los propios migrantes, quienes buscan promover reformas electorales y políticas relacionadas con su condición social.