Mathematical Optimization Approach for Facility Layout on Several Rows

The facility layout problem is concerned with finding an arrangement of non-overlapping indivisible departments within a facility so as to minimize the total expected flow cost. In this paper we consider the special case of multi-row layout in which all the departments are to be placed in three or more rows, and our focus is on, for the first time, solutions for large instances. We first propose a new mixed integer linear programming formulation that uses continuous variables to represent the departments’ location in both x and y coordinates, where x represents the position of a department within a row and y represents the row assigned to the department. We prove that this formulation always achieves an optimal solution with integer values of y, but it is limited to solving instances with up to 13 departments. This limitation motivates the application of a two-stage optimization algorithm that combines two mathematical optimization models by taking the output of the first-stage model as the input of the second-stage model. This algorithm is, to the best of our knowledge, the first one in the literature reporting solutions for instances with up to 100 departments.publishersversionpublishe

Mathematical optimization approaches for facility layout problems: The state-of-the-art and future research directions

Sem PDF conforme despacho. Fundacao para a Ciencia e a Tecnologia - PEstOE/MAT/UI0297/2014.Facility layout problems are an important class of operations research problems that has been studied for several decades. Most variants of facility layout are NP-hard, therefore global optimal solutions are difficult or impossible to compute in reasonable time. Mathematical optimization approaches that guarantee global optimality of solutions or tight bounds on the global optimal value have nevertheless been successfully applied to several variants of facility layout. This review covers three classes of layout problems, namely row layout, unequal-areas layout, and multifloor layout. We summarize the main contributions to the area made using mathematical optimization, mostly mixed integer linear optimization and conic optimization. For each class of problems, we also briefly discuss directions that remain open for future research.publishe

Time Reduction of the Packing Process

Savana is a company in the footwear sector which is over 27 years old and has more than 150 employees. This company specializes in children’s footwear of sizes ranging from 18 to 40. Each pair is individually packed in a box which is customized for each client. The ideal size of each box depends on the model of the footwear and the position in which it is placed inside the box. These boxes are ordered from an external supplier that has only certain measures available, so boxes of the same size have to be used for footwear of various sizes and models. Due to a frequent introduction of new models in the production environ- ment, the box sizes are initially set manually in an experimental procedure (testing), which is often time consuming. Savana challenged ESGI’s par- ticipants to study their packing process, in order to reduce the variety of box sizes, the empty space inside the boxes and to eliminate the need to perform testing, thereby reducing the time and increasing the e�ciency of the packing process. Furthermore, the footwear ordered by each customer is packed into large boxes, which will henceforth be referred to as containers. With regard to these large boxes, various designs and sizes can be delivered to a single client. The dimensions, weight and forms of these are subject to the customer’s specifications. In this context, Savana intends to determine automatically the sizes of the containers to be sent to each customer and how to arrange the individual boxes for each client’s order. This report tells how to automatize and speed up the overall process. It describes how to automatically assign shoes to boxes, and gives a manner to pack the shoe boxes, in such way that permit to reduce the size of the card box. Savana should be aware that this is not yet a ready to use solution, because more data analysis need to be done, in order to improve and make the method reliable. Furthermore, during implementation it may appear new important challenges

Effect of dietary grape pomace on fattening rabbit performance, fatty acid composition, and shelf life of meat

The use of agroindustry by-products in animal diets allows the use of residues that are not fit for human consumption. In this study, it was investigated whether fattening commercial rabbits during 30 days with a non-medicated feed, with 20% addition of grape pomace (GPD), affected production traits and the fatty acid composition, antioxidants properties, and the shelf life of the meat compared to a conventional strategy (CON). Furthermore, it was tested, by chromatographic analysis, whether this alternative diet allowed the transfer of phenolic compounds to the meat. Thirty-six weaned rabbits were allotted to the two treatments. In each treatment, 18 rabbits were fattened in three indoor cages, each housing three males and three female rabbits. No significant differences were found in live weights (p > 0.05), but the feed conversion rate and carcass weight and yield were found to be impaired in the GPD group (p = 0.05). The GPD group had a higher intramuscular fat percentage (2.01 vs. 1.54), improved polyunsaturated/saturated fatty acids ratio (0.75 vs. 0.66), and better atherogenicity (0.71 vs. 0.83) and thrombogenicity (1.14 vs. 1.24) indexes, while the n-6/n-3 ratio was higher (25.4 vs. 20.3). Total volatile basic nitrogen in meat was lower in the GPD group (p = 0.01), suggesting a delayed spoilage. However, no improvements in total phenolic content, antioxidant capacity, reducing power, and lipid oxidation (p > 0.05) were found in the meat. Even though the GPD pellets offered to the animals had several grape-derived phenolic compounds, and higher antioxidant properties compared to the CON diet, none of the phenolic compounds detected in feeds were detected in the meat samples. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Influence of strains and environmental cultivation conditions on the bioconversion of ergosterol and vitamin D 2 in the sun mushroom

The fungus Agaricus subrufescens is grown commercially in China, the USA, Brazil, Taiwan and Japan, among others. However, each country adopts a cultivation system that significantly influences the agronomical parameters and chemical composition of the harvested mushrooms. In this study, the influence of the cultivation process on the content of ergosterol and vitamin D2 was evaluated. RESULTS: Four commercial strains of A. subrufescens (ABL 04/49, ABL CS7, ABL 18/01 and ABL 19/01) and two environmental cultivation conditions (in the field and a controlled chamber with the absence of sunlight) were used. Infield cultivation, ABL CS7 and ABL 19/01 strains presented better agronomic parameters, whereas in a protected environment ABL 19/01, ABL 04/49 and ABL 18/01 demonstrated better performance, respectively. The highest biological efficiency value (64%) was provided by ABL 19/01 strain in a controlled environment. CONCLUSION: The highest content in ergosterol (990 mg kg−1) and vitamin D2 (36.8 mg kg−1) were observed in mushrooms obtained in the field from strain ABL 04/49, which presents reasonable agronomic parameters for cultivation.This research was funded by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP No. 2017/22501-2 for CVS, 2019/12605-0 for DMMS and 2018/21492-2 for DCZ, 19/00419-8 for WGVJ). The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); national funding by FCT, PI, through the institutional scientific employment program contracts for A Fernandes and L Barros. This work is funded by the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project Mobilizador ValorNatural®.info:eu-repo/semantics/publishedVersio

Biochemical approaches on commercial strains of Agaricus subrufescens growing under two environmental cultivation conditions

In the present work, the effect of the cultivation process, in the field and under a con- trolled environment, on biochemical parameters by using commercial strains of A. subrufescens were evaluated. The results obtained revealed that the strains cultivated in the field presented higher levels for most of the parameters evaluated (organic acids (20.5–48.0 g/100 g dw), tocopherols (107.0–198.6 μg/100 g dw), and phenolic acids and related compounds (245.2–359.0 μg/100 g dw and 10.6–23.7 μg/100 g dw, respectively)), except for the carbohydrates (53.4–72.6 g/100 g dw), energetic value (373–380 Kcal/100 g dw), and total free sugars (28.8–43.1 g/100 g dw), parameters in which the strains grown in a controlled environment present better results. For both cultivation systems, similar results were obtained regarding saturated, monounsaturated, and polyunsaturated fatty acids, as well as antioxidant and antimicrobial activities. These data contribute to the knowledge and highlight the characterized strains and the cultivation process, which can be used to obtain ingredients with potential applicability as a source of functional compounds.This research was funded by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP no. 19/00419-8 and 2018/21492-2). The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); national funding by FCT, P.I., through the institutional scientific employment program-contract for A.F., C.P. and L.B. contracts. This work is funded by the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project Mobilizador ValorNatural®.info:eu-repo/semantics/publishedVersio

Produção orgânica de calêndula: um estudo de caso.

Apresenta-se caracterização do processo de produção agrícola orgânica de Calendula officinalis L. no Estado de Santa Catarina, evidenciando particularidades e discrepâncias frente aos modelos já descritos na literatura especializada, a partir de visitas a campo, observação participante e entrevistas com um produtor de plantas medicinais. Identificaram-se como principais particularidades a saúde na agricultura familiar, demonstrada pela prática da cultura orgânica, além do controle de pragas e manuseio da produção. Os principais problemas ou divergências evidenciados foram: características do solo; época de plantio da calêndula e suas etapas posteriores, como transplante e floração. Aspectos da colheita foram discrepantes quanto ao período do dia indicado para o procedimento, bem como a ausência de informações do produtor quanto à existência de outros incentivos governamentais ao setor agrícola. Recomenda-se aos extensionistas rurais e/ou instituições competentes que busquem orientar os produtores orgânicos de calêndula para promover a adequação das práticas de cultivo dessa espécie medicinal