Aldo Artur Belardi, José Roberto Cardoso and Carlos Antonio França Sartori
Presents the mathematical basis and some results, concerning the application of Haar's wavelets, as an expansion function, in the method of moments to solve electrostatic…
Abstract
Presents the mathematical basis and some results, concerning the application of Haar's wavelets, as an expansion function, in the method of moments to solve electrostatic problems. Two applications regarding the evaluation of linear and surface charge densities were carried out: the first one on a finite straight wire, and the second one on a thin square plate. Some optimization techniques were used, whose main computational performance aspects are emphasized. Presents comparative results related to the use of Haar's wavelets and the conventional expansion functions.
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André Tosin, Willian Gerlach Dietz, Carlos Antonio França Sartori and José Roberto Cardoso
This paper aims to present an evaluation of the crosstalk models developed for a shareware version of Spice.
Abstract
Purpose
This paper aims to present an evaluation of the crosstalk models developed for a shareware version of Spice.
Design/methodology/approach
The transmission line model is compared with π lumped circuit models by varying the number of cells. The influence of losses is also introduced, and some constraints regarding the models are examined, showing the suitability of the new Spice libraries developed by the authors. In order to validate the theoretical results some experiments were carried out.
Findings
The paper finds that Spice is a powerful engineering tool for students and technicians involved in EMC analyses.
Originality/value
The main aspects concerning the accuracy and integrity of the experimental data are emphasized and discussed in this paper.
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Luiz Lebensztajn, Carina A.R. Marretto, Fábio A.B. Perdiz, Maurício C. Costa, Silvio I. Nabeta, Álvaro B. Dietrich, Ivan E. Chabu, Thiago T.G.R. Cavalcanti and José Roberto Cardoso
The design of electrical machines includes the computation of several requirements and, in general, the improvement of one requirement implies in a degradation of another one…
Abstract
Purpose
The design of electrical machines includes the computation of several requirements and, in general, the improvement of one requirement implies in a degradation of another one: this is a typical multi‐objective scenario. The paper focuses on the multi‐optimization analysis of a special switched reluctance motor.
Design/methodology/approach
Two design requirements were analyzed: the average torque and the ripple torque. The electromagnetic field computation was performed by the finite element method and the torque was computed by the Coulomb's Virtual Work for several positions. This allows us to calculate the average torque and the ripple torque. Three different methods were used to obtain the Pareto set: a min‐max approach, the non‐dominated sorting genetic algorithm (NSGA) and the strength Pareto evolutionary algorithm (SPEA). In order to save the computation time, the objective functions (the average torque and the ripple torque) were replaced with surrogate functions. Kriging models were used as surrogate functions.
Findings
The evolutionary methods (NSGA and SPEA) have a similar performance. The min‐max has not the same performance. It could have the same performance only if some unconstrained optimization problems are solved before the multi‐objective optimization. The maximum relative deviation between the approximated function (Kriging model) and the same value calculated by the finite element method was equal to 0.8 percent for the average torque and 1.2 percent for the ripple torque. The ripple torque, considered as the difference between the maximum and the minimum values in the 0‐90° region, has reduced while its frequency has doubled. This last characteristic provides a better mechanical stability for the driven load because its inertia softens the ripple effects at the double the frequency. The optimized prototype presents higher torques in the region θ<0° and this allows the electronic drive to switch in a broader range rendering the motor operation more flexible.
Originality/value
The use of surrogate functions save the computation time with high accuracy. This is very important on the design of electrical machines, a typical multi‐objective scenario. Evolutionary methods seem to be well suited to solve this class of problem.
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Aldo Artur Belardi, José Roberto Cardoso and Carlos Antonio França Sartori
This paper presents the mathematical basis, and some results, concerning the application of the Haar's Wavelets as the expansion function in the method of moments. Some…
Abstract
This paper presents the mathematical basis, and some results, concerning the application of the Haar's Wavelets as the expansion function in the method of moments. Some computational optimization techniques are used, and their main aspects are stressed in the paper. As an example, the surface charge density on a finite and thin plane plate calculation is presented, in which the main computational performance aspects are evaluated.
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Barbara de Lima Voss, David Bernard Carter and Bruno Meirelles Salotti
We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in…
Abstract
We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in the construction of hegemonies in SEA research in Brazil. In particular, we examine the role of hegemony in relation to the co-option of SEA literature and sustainability in the Brazilian context by the logic of development for economic growth in emerging economies. The methodological approach adopts a post-structural perspective that reflects Laclau and Mouffe’s discourse theory. The study employs a hermeneutical, rhetorical approach to understand and classify 352 Brazilian research articles on SEA. We employ Brown and Fraser’s (2006) categorizations of SEA literature to help in our analysis: the business case, the stakeholder–accountability approach, and the critical case. We argue that the business case is prominent in Brazilian studies. Second-stage analysis suggests that the major themes under discussion include measurement, consulting, and descriptive approach. We argue that these themes illustrate the degree of influence of the hegemonic politics relevant to emerging economics, as these themes predominantly concern economic growth and a capitalist context. This paper discusses trends and practices in the Brazilian literature on SEA and argues that the focus means that SEA avoids critical debates of the role of capitalist logics in an emerging economy concerning sustainability. We urge the Brazilian academy to understand the implications of its reifying agenda and engage, counter-hegemonically, in a social and political agenda beyond the hegemonic support of a particular set of capitalist interests.
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José Roberto Díaz-Reza, Jorge Luis García-Alcaraz, Alfonso Jesus Gil-López, Julio Blanco-Fernández and Emilio Jimenez-Macias
The purpose of this paper is to measure the relationships between advanced manufacturing technologies (AMTs) categories (stand-alone, intermediated and integrated systems…
Abstract
Purpose
The purpose of this paper is to measure the relationships between advanced manufacturing technologies (AMTs) categories (stand-alone, intermediated and integrated systems) implementation and design, process and commercial benefits obtained.
Design/methodology/approach
A survey is designed with benefits gained from AMT implementation as well as its categories, which is applied to the maquiladora industry. A structural equation model with data from 383 responses is used to measure the relationship between AMT categories and benefits gained using nine hypotheses that are tested statistically significant using partial least squares. Also, using conditional probabilities, a sensitivity analysis reports how low and high levels from AMT implementation influence on the obtained benefits.
Findings
Integrated systems are the most important AMT for maquiladoras and have the strongest impact on design, processes and commercial benefits.
Research limitations/implications
Data obtained support the model, but results may be different in another industrial sector and countries with different labor culture and technological level.
Practical implications
Managers in maquiladora industry must focus their attention on integrated manufacturing systems, because high implementation levels guarantee the biggest probability to gain benefits in design, production process and commercial.
Originality/value
The relationship between AMT and their benefits has not been measured in depth, and this paper contributes to understand that problem. In addition, this paper is the first to report a sensitivity analysis that enables managers to acknowledge the probability of obtaining certain benefits.
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Daniel Bernardo Ribeiro, Aparecido dos Reis Coutinho, Walter Cardoso Satyro, Fernando Celso de Campos, Carlos Roberto Camello Lima, José Celso Contador and Rodrigo Franco Gonçalves
Construction industry (CI) has great prominence for the world economy, and it is expected that, with the use of the innovative technologies and approaches of Industry 4.0 (I4.0)…
Abstract
Purpose
Construction industry (CI) has great prominence for the world economy, and it is expected that, with the use of the innovative technologies and approaches of Industry 4.0 (I4.0), the new industrial paradigm, construction can reach higher levels of productivity. This study aims to develop a model (readiness model) to assess the level of use of I4.0 technologies by the construction sector in Brazil and its most relevant applications.
Design/methodology/approach
The methodology used was bibliographic research, design-science research and a survey to validate the model, carried out with 162 companies, considered among the main ones in the sector in Brazil. The literature review revealed 13 technologies of I4.0 applied to construction; hence, the views of industry experts were based on these technologies.
Findings
The Digital Advancement Within CoNstruction (DAWN) readiness model was proposed, showing that among the 13 evaluated technologies of I4.0 and their applications, the Brazilian construction companies had a low level of utilization; both high and middle-income companies presented this low level of use; some technologies with a greater number of scientific publications were less used in practice in the Brazilian construction.
Originality/value
The originality and theoretical contribution are to present a readiness model to assess the level of use of I4.0 technologies and their most relevant applications in the CI in countries with an economy similar to Brazil’s, making it possible to measure the level of adoption of these technologies.
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Marcelo Santiago Sousa, Pedro Paglione, Roberto Gil Annes Silva, Flavio Luiz Cardoso-Ribeiro and Sebastião Simões Cunha
The purpose of this paper is to present a mathematical model of one very flexible transport category airplane whose structural dynamics was modeled with the strain-based…
Abstract
Purpose
The purpose of this paper is to present a mathematical model of one very flexible transport category airplane whose structural dynamics was modeled with the strain-based formulation. This model can be used for the analysis of couplings between the flight dynamics and structural dynamics.
Design/methodology/approach
The model was developed with the use of Hamiltonian mechanics and strain-based formulation. Nonlinear flight dynamics, nonlinear structural dynamics and inertial couplings are considered.
Findings
The mathematical model allows the analysis of effects of high structural deformations on airplane flight dynamics.
Research limitations/implications
The mathematical model has more than 60 degrees of freedom. The computational burden is too high, if compared to the traditional rigid body flight dynamics simulations.
Practical implications
The mathematical model presented in this work allows a detailed analysis of the couplings between flight dynamics and structural dynamics in very flexible airplanes. The better comprehension of these couplings will contribute to the development of flexible airplanes.
Originality/value
This work presents the application of nonlinear flight dynamics-nonlinear structural dynamics-strain-based formulation (NFNS_s) methodology to model the flight dynamics of one very flexible transport category airplane. This paper addresses also the way as the analysis of results obtained in nonlinear simulations can be made. Comparisons of the NFNS_s and nonlinear flight dynamics-linear structural dynamics methodologies are presented in this work.
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Euro Marques Júnior, Jose Alcides Gobbo, Fernando Fukunaga, Roberto Cerchione and Piera Centobelli
This paper aims to highlight the degree of diffusion and intensity of use of knowledge management systems (KMSs) among small and medium enterprises (SMEs) in Brazil and apply a…
Abstract
Purpose
This paper aims to highlight the degree of diffusion and intensity of use of knowledge management systems (KMSs) among small and medium enterprises (SMEs) in Brazil and apply a taxonomy that synthesizes the strategies of use of KMSs by the SMEs. In addition, it seeks to better understand the processes, practices and technologies of KM by SMEs, pointing improvements in the KMS of Brazilian SMEs and contributing to obtain better results in the search for efficiency and innovation.
Design/methodology/approach
Based on a literature review on KMSs used by SMEs, an empirical investigation was conceived, developed and conducted through online questionnaires involving 49 selected SMEs operating in several sectors.
Findings
This paper reinforces the results of the previous work of Cerchione and Esposito (2017) that point to the existence of a reciprocal relationship between KM-Tools and KM-Practices: one reinforces the other and vice versa. On the other hand, it indicates a difference in the behavior of Brazilian companies in relation to the sample of Italian companies studied by Cerchione and Esposito (2017), which presented a negative correlation between the general differentiation index and the general use intensity index of SMEs, while the Brazilian ones showed a positive correlation.
Research limitations/implications
The study points out the need for greater dissemination of practices and tools to support knowledge management (KM), as well as greater support for the implementation and effective use of these practices and tools within the organizational context of SMEs.
Practical implications
This paper identifies the main practices and tools to support KM used by Brazilian SMEs, indicating the need for investments in employee training and acquisition of tools.
Social implications
SMEs represent an important part of the generation of jobs and income in Brazil. Initiatives that lead to the successful implementation of tools and practices to support KM can increase the efficiency and productivity of these organizations.
Originality/value
This paper applies in a sample of Brazilian companies the taxonomy proposed by Cerchione and Esposito (2017) combining strategies of SMEs for the use of KMSs.
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José H. Bortoluci and Robert S. Jansen
While sharing fundamental similarities with other colonial and post-colonial experiences, Latin America has a unique history of having been the proving ground for early Spanish…
Abstract
While sharing fundamental similarities with other colonial and post-colonial experiences, Latin America has a unique history of having been the proving ground for early Spanish and Portuguese imperial projects, of having experienced a relatively long duration of – but also historically early end to – these projects, and of negotiating a particular and complex trajectory of internal and external post-colonial relations. What can the study of this distinct colonial and post-colonial experience contribute to a broader program of postcolonial sociology? Conversely, what can a revitalized postcolonial sociology contribute to the study of Latin America? This article develops provisional answers to these questions by reviewing major currents in South and North American scholarship on the Latin American colonial and post-colonial experience. Some of this scholarship self-consciously identifies with broader movements in postcolonial studies; but much of it – both historical and contemporary – does not. By bringing together diverse strands of thought, this article sheds new light on what postcolonialism means in the Latin American context, while using the comparative leverage that this set of often overlooked cases provides to contribute to a new program of postcolonial sociology.