Companies are frequently confronted with the need to order different types of items from a single supplier or to manufacture the items in a production line. Indeed, coordinated ordering of multiple items may lead to important savings whenever a family of items can be ordered from a common supplier, produced in a common facility, or use a common mode of transportation. The Joint Replenishment Problem (JRP) tackles the coordinated replenishment of multiple items by minimizing the total cost, composed of ordering (or setup) costs and holding costs, while satisfying the demand. On the other hand, when items are subject to obsolescence, they may face an abrupt decline in demand as they are no longer needed. This decline can be caused by reasons such as rapid advancements in technology, going out of fashion, or ceasing to be economically viable. The present article develops an extension of the JRP where the items may suddenly become obsolete during an infinite planning horizon. The point at which an item becomes obsolete is uncertain. The lifetimes of the items are assumed to follow independent negative exponential distributions. A model is proposed by using the total expected discounted cost as the minimization criterion. The time value of money is considered through an appropriate discount rate. Extensive tests were performed to assess the impact of obsolescence rates and discount rates on the ordering policies. The progressive increase of the obsolescence rates determines smaller periods between successive replenishments, while the progressive increase of the discount rate determines smaller lot sizes.

Production scheduling is a crucial task in the manufacturing process. In this way, the managers must decide the job's production schedule. However, this task is not simple, often requiring complex software tools and specialized algorithms to find the optimal solution. In this work, a multi-objective optimization model was developed to explore production scheduling performance measures to help managers in decision-making related to job attribution under three simulations of parallel machine scenarios. Five important production scheduling performance measures were considered (makespan, tardiness and earliness times, number of tardy and early jobs), and combined into three objective functions. To solve the scheduling problem, three multi-objective evolutionary algorithms are considered (Multi-objective Particle Swarm Optimization, Multi-objective Grey Wolf Algorithm, and Non-dominated Sorting Genetic Algorithm II), and the set of optimum solutions named Pareto Front, provided by each one is compared in terms of dominance, generating a new Pareto Front, denoted as Final Pareto Front. Furthermore, this Final Pareto Front is analyzed through an automatic bio-inspired clustering algorithm based on the Genetic Algorithm. The results demonstrated that the proposed approach efficiently solves the scheduling problem considered. In addition, the proposed methodology provided more robust solutions by combining different bio-inspired multi-objective techniques. Furthermore, the cluster analysis proved fundamental for a better understanding of the results and support for choosing the final optimum solution.

Herein, modern green synthesis approaches are studied to assemble N-heterylarenes scaffolds via a non-catalyzed intramolecular 5/6-exo-dig cyclocondensation reaction based on the in-situ generation of arenehydrazonopentan-/hexan-2-one. Accordingly, the formation of two N-heteryl moieties, pyrazol-1-yl and pyridazin-1(4H)-yl, was initially studied. Therefore, appropriate fluorophenyl was first converted into their respective phenylhydrazine by SNAr reaction and then reacted with different trigonal carbonyl bielectrophiles (-CO-, -CO₂R, and -CO₂H) in ethanol in the presence of US, MW, IR, and an IR· US irradiation mixture. Cyclic nitrogenous cores were best obtained when subjected to microwave irradiation with ketone and arylhydrazine as starting reagents, allowing them to get excellent yields quickly. Arylhydrazine reactants featuring Π-donor groups underwent the best 5/6-exo-dig type annulment reaction. Presumably, the observed improvements in EDG-dependent reaction efficiency reflect changes in the nucleophilicity of arylhydrazines intermediates as α-nucleophilic reactants.

Real life inventory lot sizing problems are frequently challenged with the need to order different types of items within the same batch. The Joint Replenishment Problem (JRP) addresses this setting of coordinated ordering by minimizing the total cost, composed of ordering (or setup) costs and holding costs, while satisfying the demand. The complexity of this problem increases when some or all item types are prone to obsolescence. In fact, the items may experience an abrupt decline in demand because they are no longer needed, due to rapid advancements in technology, going out of fashion, or ceasing to be economically viable. This article proposes an extension of the Joint Replenishment Problem (JRP) where the items may suddenly become obsolete at some time in the future. The model assumes constant demand and the items’ lifetimes follow independent negative exponential distributions. The optimization process considers the time value of money by using the expected discounted total cost as the minimization criterion. The proposed model was applied to some test cases, and sensitivity analyses were performed, in order to assess the impact of obsolescence on the ordering policy. The increase in the obsolescence risk, through the progressive increase of the obsolescence rates of the item types, determines smaller lot sizes on the ordering policy. The increase in the discount rate causes smaller quantities to be ordered as well.

Since the late 80’s the Structural Analysis Research Group of the Instituto Superior Técnico (IST) has been involved in the development of non-conventional finite element formulations in order to overcome some of the limitations associated with the use of the CFE method and to develop high performance numerical tools for the analysis of structural engineering problems. Several alternative models for the linear and non-linear structural analysis have been developed using hybrid and mixed models techniques. These works are summarized in this paper, in which their past and future applications of this formulation in non-linear analysis of structures are fully detailed.

In this work, the study of the evolutive behaviour of composite steel-concrete sections used in bridge decks was performed. A new method is proposed for the annex of EC3 part 2, in order to study the evolution effective steel area in a composite section, for serviceability and ultimate states. A coherent theoretical framework is presented, based on several relevant codes, namely the new Eurocodes. With this framework, a computer program is developed taking into account several important aspects in the behaviour of steel-concrete composite sections, such as nonlinear stress-strain relationships of the materials, local buckling of steel plates, time-dependent effects in concrete behaviour and load history. Also a new algorithm is proposed in order to compute strain fields at the section level from a known set of internal forces in the section, in nonlinear constitutive relations. Results obtained with the developed computer program are presented for several examples of typical sections found in bridge decks. Those results include moment-curvature plots, evolution of the strain field, evolution of the neutral axis, evolution of the stress in some points of the section. The influence of the concrete ultimate resistance and the staged construction sequence in the behaviour of the section is also evaluated.

This paper presents recent research, concerning some preliminary design guidelines to be applied in GFRP composite sandwich panels, for civil engineering applications. For more than a decade, the foundations of preliminary design of concrete, wood and steel structures, have been fully established in structural design codes and technical recommendations. Since FRP structures at the moment possess no standard design code, its preliminary design guidelines are nowhere to be found. This work pretends to fill this gap in knowledge, by providing simple and clear design guidelines to be applied in classical known GFRP composite sandwich panels, more specifically in home buildings. Just like in concrete structures, for GFRP structures one of the most unfavourable design state is the serviceability, mainly due to the long term deflection. Therefore, this long term deflection will be used to estimate the minimum span/height ratio necessary to “indirectly” verify the serviceability state. This is performed using an extensive parametric analysis: of the span beam model; type of materials; type of support; load levels; and geometrical properties. In this work in order to correctly estimate the flexural and shear deflection, the Carrera Unified Formulation is used, therefore no simplified shear correction factor is needed.

In the scope of Behavioral Decision Theory, Accounting-based Earnings Management (AEM) may compromise the success of decision making of a firm’s stakeholders. Given that AEM constitutes a barrier to the decision-making process, we aim to identify the main motivations of the players of AEM. Besides, in this study we also intend to analyze the implementing and detecting of AEM practices in financial statements and to evaluate whether individual characteristics influence the ability to implement and detect creative accounting practices. To achieve the proposed objectives, a quantitative methodology approach was used. A survey was applied to Portuguese’s certified accountants. In the data analyses, we applied the univariate and multiple analysis. Based on 159 observations, we find that most certified accountants indicate the main motivations are related to the reduction of the cost of capital and tax burden, the strength of the “code law system”, and that the managers are the main players. Our evidence also shows that the AEM practices are easily implemented and detected in the financial statements. In addition, we find that age, professional experience, and academic qualifications of the certified accountant tend to have an impact on the ability to implement AEM in the financial statements, contrary to gender and training area. Furthermore, gender and academic financial statements. This research is important for the development of the literature, entities that operate in accounting standardization and for the users of accounting and financial information. This study contributes to a better understanding of AEM practice, and it originally combines individual characteristics of accounting professionals with AEM practice.

The role accounting plays in decision-making in business is a broad topic that has driven academics. This paper is grounded on decision and utility theories. It investigates the Certified Accountants' perception of financial information (FI) usefulness and the company's performance. Based on data collected through a survey applied to certified accountants, this study develops and evaluates an original theoretical model using the Structural Equations Model (SEM). The results reveal that manager's gender and academic qualifications influence the perception of FI utility. Non-owner managers and older companies also attach more significance to FI in decision making. The managers who attribute the most usefulness to FI in decision-making are those of companies with higher performance. Additionally, the results show that the FI usefulness is a mediator variable in the relationship between the characteristics above and company performance. This research helps all stakeholders improve decision-making, studying past events with FI to predict future results and consequently increase the company's success.

This paper presents a new hybrid double mixed stress (4f-HMS) model, for the static analysis of isotropic plane structures, in which it is assumed a physically and geometrically linear behaviour. The main improvement of this model is, it approximates independently the three most important fields in the domain, more specifically the strain field, the stress field and the displacement field of each element. The displacements along the static boundary, considered to include inter-element boundaries, are also directly approximated. For the approximation functions in the space domain, a complete set of orthonormal Legendre polynomials are used. The adoption of these functions enables the use of analytical closed form solutions, for the computation of all linear structural operators, and leads to the development of very effective p- refinement procedures. The model being discussed is tested in terms of convergence capabilities using classical elastic strain energy and other common variables, in which the monotonic convergence is tested. To validate the model and to illustrate its potential, several numerical examples are discussed and comparisons are made, with solutions obtained using analytical results and other known finite element formulations.