Modeling and simulating a textile production system

This paper presents a study for a production scheduling problem in a textile company, specifically in the weaving preparation area. Basically, the processing orders can be considered as sequential working steps trough three operations (charging - weaving - discharging), and the goal is to minimize time variation and to avoid delays. The machine utilization should be as higher as possible due to short delivering deadlines. The production unit has got 4 of these weaving machines functioning at the same time. Four dispatching rules were tested in order to find the best solution. The optimization procedure highlighted some interesting issues that are discussed in this paper

An Evidence-based Roadmap for IoT Software Systems Engineering

Context: The Internet of Things (IoT) has brought expectations for software inclusion in everyday objects. However, it has challenges and requires multidisciplinary technical knowledge involving different areas that should be combined to enable IoT software systems engineering. Goal: To present an evidence-based roadmap for IoT development to support developers in specifying, designing, and implementing IoT systems. Method: An iterative approach based on experimental studies to acquire evidence to define the IoT Roadmap. Next, the Systems Engineering Body of Knowledge life cycle was used to organize the roadmap and set temporal dimensions for IoT software systems engineering. Results: The studies revealed seven IoT Facets influencing IoT development. The IoT Roadmap comprises 117 items organized into 29 categories representing different concerns for each Facet. In addition, an experimental study was conducted observing a real case of a healthcare IoT project, indicating the roadmap applicability. Conclusions: The IoT Roadmap can be a feasible instrument to assist IoT software systems engineering because it can (a) support researchers and practitioners in understanding and characterizing the IoT and (b) provide a checklist to identify the applicable recommendations for engineering IoT software systems

Comparação de dois algoritmos genéticos aplicados ao TOP

A recolha seletiva de resíduos sólidos urbanos para reciclagem é um processo dispendioso, especialmente quando realizado em grande escala. Um problema importante neste processo reside na gestão de uma frota, uma vez que atualmente as estratégias utilizadas geralmente têm baixa eficiência. O processo de recolha seletiva de resíduos sólidos urbanos pode ser modelado como um problema de encaminhamento de veículos, em particular como um Problema de Orientação de Equipas (TOP - Team Orienteering Problem). No TOP uma frota de veículos é incumbida de visitar um conjunto selecionado de vértices, de modo a maximizar o luvro total. O objetivo deste trabalho é o de otimizar o processo de recolha selectiva de resíduos sólidos urbanos ao abordar as questões relacionadas com a gestão de uma frota. Isso deve ser alcançado através do desenvolvimento de uma ferramenta de software que implementa um algoritmo genético para resolver o modelo desenvolvido. Neste artigo apresentamos e comparamos dois algoritmos genéticos através de experiências computacionais realizadas com instâncias de teste conhecidas da literatura. O uso de algoritmos genéticos para resolver o TOP mostra ser uma escolha acertada, pois o método é eficiente produzindo bons resultados num tempo aceitável.Fundos FEDER através do Programa Operacional Fatores de Competitividade – COMPETE e por Fundos Nacionais através da FCT – Fundação para a Ciência e Tecnologia no âmbito do Projeto: FCOMP-01-0124-FEDER-022674GATOP - Genetic Algorithms for Team Orienteering Problem (Ref PTDC/EME-GIN/ 120761/2010), financiado por fundos nacionais pela FCT / MCTES e co-financiado pelo by the European Social Development Fund (FEDER) through the COMPETE Programa Operacional Fatores de Competitividade (POFC) Ref FCOMP-01-0124-FEDER-020609

Layout and process optimisation: using computer-aided design (CAD) and simulation through an integrated systems design tool

The design of production and logistic systems is a process of managing both technical and organisational variants in order to identify the best solution for a given system. This paper discusses design issues of production systems that are applied to an internal logistic system in the automotive industry. As far as the production systems design (PSD) is concerned, three basic classes of software tools usually pertain: computer-aided design (CAD), process simulation, and information systems. However, these software tools have been used with low levels of integration. Vik et al. (2010b, 2010c) proposed integrating these software resources in production systems and developed an advanced tool called integrated design of systems (IDS). The proposed IDS tool involves a wide set of functions for the most common tasks of PSD, from conceptualisation to implementation, including systems analysis (P-Q, cluster, and material flow analysis), automatic generation of simulation models, generation of alternatives for the layout of facilities and factories, material flows display, transportation system design, and iterative buffer size specification. The IDS approach takes advantage of simulation, CAD systems, and their integration. This paper will demonstrate the concept and functionalities of the proposed tool in a real industrial case study.Fundação para a Ciência e Tecnologi

Comparison of SIMIO and ARENA simulation tools

The purpose of this paper is to establish a comparison between Simio and Arena, helping a vast community of simulation practitioners to gain access to advanced modelling capabilities to address complex problems. Several aspects were compared, such as: concept of simulation models, animation development, modelling philosophies, Simio libraries and Arena templates, concept of entities, interface of the tools and Simio objects versus Arena blocks. The comparison was consolidated through the analysis of two case studies where the authors aimed to emphasize the way each simulation tool addresses some important issues related to model construction. The several compared aspects indicate the many advantages of using the more recent tool. Thus, this object-oriented tool appears to have all the conditions to trigger a widespread paradigm shift in the way practitioners build models.This work has been supported by FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEst-OE/EEI/UI0319/2014

SPLACE: A tool to automatically SPLit, Align, and ConcatenatE genes for phylogenomic inference of several organisms

The reconstruction of phylogenomic trees containing multiple genes is best achieved by using a supermatrix. The advent of NGS technology made it easier and cheaper to obtain multiple gene data in one sequencing run. When numerous genes and organisms are used in the phylogenomic analysis, it is difficult to organize all information and manually align the gene sequences to further concatenate them. This study describes SPLACE, a tool to automatically SPLit, Align, and ConcatenatE the genes of all species of interest to generate a supermatrix file, and consequently, a phylogenetic tree, while handling possible missing data. In our findings, SPLACE was the only tool that could automatically align gene sequences and also handle missing data; and, it required only a few minutes to produce a supermatrix FASTA file containing 83 aligned and concatenated genes from the chloroplast genomes of 270 plant species. It is an open-source tool and is publicly available at https://github.com/reinator/splace

A flexible decision support tool for maintenance float systems: a simulation approach

This paper is concerned with the use of simulation as a decision support tool in maintenance systems, specifically in MFS (Maintenance Float Systems). For this purpose and due to its high complexity, in this paper the authors explore and present a way to develop a flexible MFS model, for any number of machines in the workstation, spare machines and maintenance crews, using Arena simulation language. Also in this paper, some of the most common performance measures are identified, calculated and analysed. Nevertheless this paper would concentrate on the two most important performance measures in maintenance systems: system availability and maintenance total cost. As far as these two indicators are concerned, it was then quite clear that they assumed different behaviour patterns, especially when using extreme values for periodic overhauls rates. In this respect, system availability proved to be a more sensitive parameter.This work was funded by the "Programa Operacional Fatores de Competitividade - COMPETE" and by the FCT - Fundação para a Ciência e Tecnologia in the scope of the project: FCOMP-01-0124-FEDER-022674

Treatment of effluents containing 2-chlorophenol by adsorption onto chemically and physically activated biochars

The application of adsorption using biochars for the remediation of effluents containing emerging contaminants, including chlorophenols, is a hotspot and trend development in the literature. This treatment is more interesting when using readily available wastes and at no cost, such as malt bagasse, for example. Here, the biochars were produced from malt bagasse, by physical and chemical activation (with CO2 and ZnCl2, respectively) and employed as adsorbents in the remediation of effluents containing 2-chlorophenol. Results revealed that the activated biochars have mesoporous structures and surface areas of 161 m² g-1 (CO2) and 545 m² g-1 (ZnCl2). For both activated biochars, adsorption of 2-chlorophenol was favored under acid conditions, with the highest adsorption capacities found using ZnCl2-activated biochar. The maximum adsorption capacity using ZnCl2-activated biochar was 150 mg g-1. The process was endothermic and spontaneous. ZnCl2-activated biochar exhibited an efficiency of 98% (using a dosage of 10 g L-1) in the treatment of industrial effluents containing 2-chlorophenol.La aplicación de la adsorción mediante biocarros para la remediación de efluentes que contienen contaminantes emergentes, incluidos los clorofenoles, es un punto crítico y un desarrollo de tendencia en la literatura. Este tratamiento es más interesante cuando se utilizan residuos fácilmente disponibles y sin costo, como el bagazo de malta, por ejemplo. Aquí, los biocarros se produjeron a partir de bagazo de malta, mediante activación física y química (con CO2 y ZnCl2, respectivamente) y se emplearon como adsorbentes en la remediación de efluentes que contienen 2-clorofenol. Los resultados revelaron que los biocarros activados tienen estructuras mesoporosas y áreas superficiales de 161 m² g-1 (CO2) y 545 m² g-1 (ZnCl2). Para ambos biocarros activados, la adsorción de 2-clorofenol se vio favorecida en condiciones ácidas, con las capacidades de adsorción más altas encontradas utilizando biocarbón activado con ZnCl2. La capacidad máxima de adsorción usando biocarbón activado con ZnCl2 fue de 150 mg g-1. El proceso fue endotérmico y espontáneo. El biocarbón activado con ZnCl2 exhibió una eficiencia del 98% (usando una dosis de 10 g L-1) en el tratamiento de efluentes industriales que contienen 2-clorofenol

Oncogenic Gain of Function in Glioblastoma Is Linked to Mutant p53 Amyloid Oligomers.

Tumor-associated p53 mutations endow cells with malignant phenotypes, including chemoresistance. Amyloid-like oligomers of mutant p53 transform this tumor suppressor into an oncogene. However, the composition and distribution of mutant p53 oligomers are unknown and the mechanism involved in the conversion is sparse. Here, we report accumulation of a p53 mutant within amyloid-like p53 oligomers in glioblastoma-derived cells presenting a chemoresistant gain-of-function phenotype. Statistical analysis from fluorescence fluctuation spectroscopy, pressure-induced measurements, and thioflavin T kinetics demonstrates the distribution of oligomers larger than the active tetrameric form of p53 in the nuclei of living cells and the destabilization of native-drifted p53 species that become amyloid. Collectively, these results provide insights into the role of amyloid-like mutant p53 oligomers in the chemoresistance phenotype of malignant and invasive brain tumors and shed light on therapeutic options to avert cancer