Petri Net Models Optimized for Simulation

Petri nets and simulation are a modeling paradigm and a tool, respectively, which may be successfully combined for diverse applications, such as performance evaluation, decision support, or training on complex systems. Simulation may require significant computer resources; hence, in this chapter, two Petri net-based formalisms are analyzed for profiting from their respective advantages for modeling, simulation, and decision-making support: a set of alternative Petri nets and a compound Petri net. These formalisms, as well as the transformation algorithms between them, are detailed and an illustrative example is provided. Among the main advantages of these formalisms, their intuitive application for modeling discrete event systems in the process of being designed, as well as the compactness that may present the resulting model, in the case of a compound Petri net, leading to efficient decision making, can be mentioned

Efecto de la manufactura esbelta, seis sigma y cadena de suministro en la sostenibilidad de maquiladoras mexicanas

La memoria de esta tesis se presenta en la modalidad de compendio de trabajos publicados en revistas científicas internacionales con revisión por pares e indexadas en Journal Citations Reports (JCR). Los trabajos publicados se indican a continuación:Artículo 1. García-Alcaraz, J. L., Montalvo, F. J. F., Avelar-Sosa, L., Pérez de la Parte, M. M., Blanco-Fernández, J., & Jiménez-Macías, E. (2020). The importance of access to information and knowledge coordination on quality and economic benefits obtained from Six Sigma. Wireless Networks, 26(8), 5713-5726. doi:10.1007/s11276-019-02180-7. Indexada en SCIE del Web of Sciences, siendo Q2 o Q3, según la categoría en la que sea analizada, con IF de 2.602 y con JIF de 53.66.Artículo 2. García-Alcaraz, J. L., Martínez-Hernández, F. A., Olguín-Tiznado, J. E. O., Realyvasquez-Vargas, A., Jiménez Macías, E., & Javierre-Lardies, C. (2021). Effect of quality lean manufacturing tools on commercial benefits gained by Mexican maquiladoras. Mathematics, 9(9). doi:10.3390/math9090971. Indexada en SCIE del Web of Sciences, siendo Q1 en la categoría de Matemathics (24/330) en el JCR 2020, con IF de 2.258 y con JIF de 92.88.Artículo 3. García-Alcaraz, J.L., Díaz Reza, J.R., Sánchez Ramírez, C., Limón Romero, J., Jiménez Macías, E., Lardies, C. J., & Rodríguez Medina, M. A. (2021). Lean manufacturing tools applied to material flow and their impact on economic sustainability. Sustainability (Switzerland), 13(19). doi:10.3390/su131910599. Indexada en SCIE del Web of Sciences, siendo Q2 o Q3 según la categoría en la que se analice en el JCR 2020, con un IF de 3.251.Artículo 4. García-Alcaraz, J. L., Díaz-Reza, J. R., Flor Montalvo, F. J., Jiménez-Macías, E., Blanco-Fernández, J., & Javierre Lardies, C. F. (2021). Effects of information sharing, decision synchronization and goal congruence on SC performance. Computers & Industrial Engineering, 162, 107744. doi:https://doi.org/10.1016/j.cie.2021.107744. Indexada en SCIE del Web of Sciences, siendo Q1 o Q2 según la categoría en la que se analice en el JCR 2020, con un IF de 5.431.<br /

Equivalent and efficient optimization models for an industrial discrete event system with alternative structural configurations

Discrete event systems in applications, such as industry and supply chain,may show a very complex behavior. For this reason, their design and operation may be carried out by the application of optimization techniques for decision making in order to obtain their highest performance. In a general approach, it is possible to implement these optimization techniques by means of the simulation of a Petri net model, which may require an intensive use of computational resources. One key factor in the computational cost of simulation-based optimization is the size of the model of the system; hence, it may be useful to apply techniques to reduce it. This paper analyzes the relationship between two Petri net formalisms, currently used in the design of discrete event systems, where it is usual to count on a set of alternative structural configurations.These formalisms are a particular type of parametric Petri nets, called compound Petri nets, and a set of alternative Petri nets. The development of equivalent models under these formalisms and the formal proof of this equivalence are the main topics of the paper.The basis for this formal approach is the graph of reachable markings, a powerful tool able to represent the behavior of a discrete event system and, hence, to show the equivalence between two different Petri net models. One immediate application of this equivalence is the substitution of a large model of a system by a more compact one, whose simulation may be less demanding in the use of computational resources

Analysis of product shrinkage and waste in a potato bagging plant

Nowadays, an average of 2 kg of waste per person are generated in Spain. Furthermore, the household consumption is rising and, as a consequence, the waste production is also increasing. This trend presents a direct impact in the environment. Moreover, after two years of COVID-19 pandemic, it has been detected a stronger rise in consumption per person, while consumption through professional commercial channels for hospitality industry has been lower. This paper analizes the waste generation and product shrinkage in a potato bagging plant, which addresses its production to both final consumers and retailers. The raw materials washing line, as well as the production line, are taken into consideration in the analysis, while new uses to the produced waste are proposed, aiming at providing new useful life, such as the production of bioplastics or the production of biodiesel. As a consequence, the environment impact is minimized and new products are obtained

Biología molecular de la asimilación de nitrato en algas

El alga verde eucariótica Chlamydomonas reinhardtii es un organismo modelo para el estudio de la biología molecular de la asimilación de nitrato. Este sistema biológico presenta excelentes cualidades para estudios bioquímicos, fisiológicos, genéticos y moleculares. Estas investigaciones han permitido los siguientes logros: i) generación de una colección de mutantes; ii) identificación y caracterización de genes para el transporte de amonio; iii) caracterización de genes del transporte biespecífico de bicarbonato/nitrito; iv) clonación y caracterización del gen que codifica la proteína portadora de cofactor de molibdeno (MCP), determinación de la estructura cristalina de la misma y de sus residuos funcionales en la unión del cofactor; v) utilización de una nueva estrategia para identificar mutantes del cofactor de molibdeno; y vi) identificación de un nuevo LTR-retrotransposón de la familia gypsy

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality