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The purpose of this paper is to present a graph representation of the design space that is suitable for the ant colony optimization (ACO) method in topology optimization (TO) problems.

The ACO is employed to obtain optimal routes in an equivalent graph representation of the discretized design space, with each route corresponding to a given distribution of material.

The problem associated with the maximization of the torque of a c‐core magnetic actuator is investigated, in which part of the yoke is discretized into a 16×8 grid and can assume three different materials: air, pure iron and a magnetic material.

The results of the c‐core magnetic actuator problem, which are in agreement with literature available, show the adequacy of the proposed approach to TO of electromagnetic devices.

The graph representation of the design space permits the solution of topological design problems with an arbitrary number of materials.

The results illustrate the potential of the methodology in dealing with multi‐domain TO problems, and the possibility to extend the application to 3D problems.

This paper aims to investigate the electroporation phenomenon in a single cell exposed to ultra short (μs) and high voltage (kV) electric pulses.

The problem is addressed by two complementary approaches. First, numerical simulations based on an asymptotic approximation derived from the Smoluchowski theory are used to calculate the pore generation, growth and size evolution at the membrane of a spherical cell model, immersed in a suspension medium and consisting of cytoplasm and membrane. The numerical calculations are solved using the finite difference method. Second, an in vitro experiment with LLC-MK2 cells is carried out in which electroporation was monitored with molecules of propidium iodide. This part also comprehended the design and manufacturing of a portable electric pulse generator capable of providing rectangular pulses with amplitude of 1,000 V and duration in the range of 1-μs to 100-μs. The pulse generator is composed of three modules: a high voltage DC source, a control module, and an energy storage and high voltage switching.

The numerical simulations considered a 5-μm radius cell submitted to a 500 kV/m rectangular electric pulse for 1-μs. The results indicate the formation of around 3,500 pores at the cell membrane, most of them, around 950, located at the poles of the cell aligned to the applied electric pulse, with radii sizes varying from 0.5-nm to 13-nm. The in vitro experiment considered exposition of LLC-MK2 cells to pulses of 200 V, 500 V, and 700 V, and 1-μs. Images from fluorescence microscopy exhibit the LLC-MK2 cells with intense red, a strong evidence of the electroporation.

The work presents a thorough study of the electroporation phenomenon combining two complementary approaches, a rigorous numerical simulation and a detailed in vitro experiment.

The purpose of this paper is to present a new multi‐objective clonal selection algorithm (MCSA) for the solution of electromagnetic optimization problems.

The method performs the somatic hypermutation step using different probability distributions, balancing the local search in the algorithm. Furthermore, it includes a receptor editing operator that implicitly realizes a dynamic search over the landscape.

In order to illustrate the efficiency of MCSA, its performance is compared with the nondominated sorting genetic algorithm II (NSGA‐II) in some analytical problems and in the well‐known TEAM benchmark Problem 22. Three performance evaluation techniques are used in the comparison, and the effect of each operator of the MCSA in its accomplishment is estimated.

In the analytical problems, the MCSA enhanced both the extension and uniformity in its solutions, providing better Pareto‐optimal sets than the NSGA‐II. In the Problem 22, the MCSA also outperformed the NSGA‐II. The MCSA was not dominated by the NSGA‐II in the three variables case and clearly presented a better convergence speed in the eight variables problem.

This paper could be useful for researchers who deal with multi‐objective optimization problems involving high‐computational cost.

The new operators incorporated in the MCSA improved both the extension, uniformity and the convergence speed of the solutions, in terms of the number of function evaluations, representing a robust tool for real‐world optimization problems.

The purpose of this paper is to present a numerical analysis of the specific absorption rate (SAR) and temperature increase in a three dimensional (3D) anatomical human eye model exposed to electromagnetic (EM) fields at 1.9, 2.4 and 5.1 GHz, in particular devices such as tablets, smart phones, etc., which are based on Wi-Fi and 4G technology.

A new 3D model of the human eye composed of nine different tissues with a high resolution of 0.5 mm is presented, including a precise definition of the cornea and lens and also distinguishing the cornea from the aqueous humor and the sclera from the retina and choroid. The EM problem is solved from the Maxwell’s equations which gives the electric field and in turn enables the calculation of the SAR in any part of the eye model. The thermal problem is solved from the bioheat (Pennes’) equation taking the SAR as an input of the power dissipated by the EM field. In both cases the finite difference time domain method is employed.

A plane-wave field located 30 cm away from the eye is considered as the source for the far-field EM exposure. The results for maximum SAR indicate that the smallest value is 0.06 W/kg in the lens for 1.9 GHz whereas the highest value encountered is 0.43 W/kg in the vitreous humor for 5.1 GHz. In the worst case, the maximum SAR in the lens is 0.28 W/kg for 5.1 GHz. In all cases, the SAR values are within the limits defined by international standards. In terms of maximum temperature, the highest value found is 0.01 C in the cornea, aqueous humor and lens for 5.1 GHz.

The work presents a thorough numerical calculation of the temperature increase in the human eye induced by devices that are based on Wi-Fi and 4G technology operating at 1.9-5.1 GHz.

The paper aims to present a new methodology for hybrid genetic algorithms (GA) in the solution of electromagnetic optimization problems.

This methodology can be seen as a local search operator which uses local quadratic approximations for each objective and constraint function in the problem. In the local search phase, these approximations define an associated local search problem that is efficiently solved using a formulation based on linear matrix inequalities.

The paper illustrates the proposed methodology comparing the performance of the hybrid GA against the basic GA in two analytical problems and in the well‐known TEAM benchmark Problem 22. For the analytical problems, 30 independent runs for each algorithm were considered whereas for Problem 22, ten independent runs for each algorithm were taken.

For the analytical problems, the hybrid GA enhanced both the convergence speed, in terms of the number of function evaluations, and the accuracy of the final result. For Problem 22, the hybrid GA was able to reach a better solution, with a better value of the standard deviation with less CPU time.

The paper could be useful both for device designers and researchers involved optimization in computational electromagnetics.

The hybrid GA proposed enhanced the convergence speed, in terms of the number of function evaluations, representing a faster and robust algorithm for practical optimization problems.

The purpose of this paper is to apply an Ant colony optimization approach for the solution of the topological design of interior permanent magnet (IPM) machines.

The IPM motor design domain is discretized into a suitable equivalent graph representation and an Ant System (AS) algorithm is employed to achieve an efficient distribution of materials into this graph.

The single-objective problems associated with the maximization of the torque and with the maximization of the shape smoothness of the IPM are investigated. The rotor of the device is discretized into a 9×18 grid in both cases, and three different materials are considered: air, iron and permanent magnet.

The graph representation used enables the solution of topological design problems with an arbitrary number of materials, which is relevant for 2 and 3D problems.

From the numerical experiments, the AS algorithm was able to achieve reasonable shapes and torque values for both design problems. The results show the relevance of the mechanism for multi-domain topology optimization of electromagnetic devices.

The purpose of this paper is to perform a comparative analysis between the productivity metrics recommended in the literature and those that companies in the knowledge-intensive services sector use in practice.

To collect information, a systematic review of the literature was used, to apply virtual surveys and interviews among managers of different companies representing the sector. For data analysis, categorical optimal scales, homogeneity tests, tetrachoric correlation matrices, word clouds and association coefficients for dichotomous variables were used.

There are association patterns between the metrics used and the nature of the work performed. Despite the heterogeneity observed in the productivity metrics, categorization guidelines related to the traditional, human resources and customer-oriented approaches emerge.

Possible neglects using metrics aimed at valuing the intellectual capital immersed in human resources are evident, particularly in the follow-up to autonomy, knowledge management, human capital, teamwork, training and capacity building metrics, among others. Conversely, face-to-face monitoring metrics, such as absenteeism, are overvaluation.

The approaches and metrics discussed and the results obtained, provide information so that knowledge-intensive companies have a reference framework to identify and select useful metrics to assess the work carried out by their workforce.

This paper aims to analyze the interrelationship that exists between expectancy-value and achievement goals as factors that are decisive for participants’ higher engagement in 12 massive open online courses (MOOCs) on energy sustainability and to determine the profile of participants achieving higher success rates.

A qualitative–quantitative study of correlational and descriptive scope is carried out on two instruments based on pre- and post-tests of 6,029 participants, which is followed by a qualitative data analysis distributed by code families to identify participants’ main motivations to take MOOCs.

The results showed a positive moderate-high correlation between expectancy-value and achievement goals, which means in a practical sense that the participants’ subjective estimates of the possibility of reaching their goals prior to the beginning of the course were fulfilled, as the intentionality of the subjects-participants was positive with respect to the contents imparted.

The profiles of participants with a higher tendency to successfully finish the course and with high rates of engagement share the following characteristics: having previously and successfully finished more than one MOOC; taking the MOOC for work purposes (promotion, seeking better job opportunities, etc.); and having intrinsic motivation, that is, not depending on external factors such as obligations and certifications.

This research suggests that there are pre-educational factors that define the trend of successful completion of MOOCs, based on expectancy-value (e.g. previous experiences with other MOOCs) and achievement goals (e.g. job improvement), with external motivational issues such as completion certificates being less prevalent in the learning intention.

The purpose of this study is to reflect on some actions carried out in Colombia, both at the governmental and organizational levels, that can be considered collaborative innovations and that have emerged within this pandemic context seeking to generate an increase in trust and the awakening of others’ emotions, as well as manifestations or expressions of trust and emotions by the population.

Through a qualitative descriptive study, innovation strategies applied by different sectors to address the current situation of preventive isolation are identified, with the subsequent identification of manifestations resulting from the execution of the strategies and analyzes of the implications in terms of emotions and confidence as research constructs.

Actions taken by the public administration, instead of generating trust and instilling positive emotions, have generated the opposite and there is evidence of greater acceptance of actions when they come from the general population through strategies that can be assimilated into the application of open collaborative innovation.

This study raises future research challenges, in addition to the practical implications that it may have in terms of the vision of the role of the state and citizens and the impact of administrative decisions regarding the generation of trust and the presence of positive emotions in a crisis context.

El presente artículo tiene como propósito principal reflexionar acerca de algunas acciones realizadas en Colombia tanto a nivel gubernamental como organizacional, que pueden ser consideradas innovaciones colaborativas y que han surgido dentro del contexto de la pandemia buscando generar un aumento de la confianza y el despertar de otras emociones, así como las manifestaciones u expresiones ante las mismas por parte de la población.

A través de un estudio descriptivo cualitativo, se lleva a cabo la identificación de estrategias de innovación aplicadas por distintos sectores para hacer frente a la situación de aislamiento preventivo, posteriormente identificando las manifestaciones a partir de la ejecución de las mismas y analizando sus implicaciones en términos de emociones y confianza como constructos de investigación.

Se ha encontrado que desde la administración pública las acciones tomadas en lugar de generar confianza e impactar con emociones positivas han generado todo lo contrario, así como se evidencia que hay mayor aceptación cuando las acciones provienen de la población en general a través de estrategias que pueden ser asimiladas a la aplicación de la innovación colaborativa abierta.

Este artículo plantea retos de investigación a futuro, además de las implicaciones prácticas que puede llegar a tener en cuanto a la visión del papel del estado, la ciudadanía y el impacto de sus decisiones administrativas en cuanto a la búsqueda de generación de confianza y de presencia de emociones positivas en un contexto de crisis.

O principal objetivo deste artigo é refletir sobre algumas ações realizadas na Colômbia, tanto em nível governamental quanto organizacional, que podem ser consideradas inovadoras em colaboração e surgiram nesse contexto de pandemia, buscando gerar um aumento da confiança e o despertar de outras pessoas. emoções, bem como as manifestações ou expressões diante deles pela população.

Através de um estudo descritivo qualitativo, é realizada a identificação de estratégias de inovação aplicadas por diferentes setores para enfrentar a situação atual de isolamento preventivo, identificando posteriormente as manifestações a partir da execução dos mesmos. e analisando suas implicações em termos de emoções e confiança à medida que a pesquisa é construída.

Constatou-se que da administração pública as ações tomadas, em vez de gerar confiança e impactar com emoções positivas, geraram o oposto, além de evidências de que há maior aceitação quando as ações vêm da população em geral por meio de estratégias que pode ser assimilado à aplicação da inovação colaborativa aberta.

Este artigo levanta desafios futuros de pesquisa, além das implicações práticas que possa ter em termos da visão do papel do Estado, da cidadania e do impacto de suas decisões administrativas em relação à busca por geração de confiança e presença de emoções positivas em um contexto de crise.

The relevance of entrepreneurship in the economic systems of the regions is well documented. Recently, a new concept has emerged in the entrepreneurship literature, entrepreneurial ecosystem (EE), to analyze the dynamics of a given territory and its outputs and impact upon entrepreneurship. Moreover, it is also well documented the close relationship between entrepreneurship and family business (FB). Keeping in mind the multidimensionality of the latter, its scholars are beginning to look into the entrepreneurial elements embedded in the family processes and the influence of context.

After an extensive literature review made, a significant gap was found, given the historical relevance that FB (SMEs the vast majority) have in the global economic systems. A FB entrepreneurial ecosystem (FBEE) model is proposed based on the data collected from two case studies, on Portugal's wine industry, and Mexico's shoe industry, both artisan industries confronted with the urge to reinvent and adapt to face deep market and industry changes.

The results should indicate the feasibility of proposing a second level on the theory of EE, the FBEE, where both the family and business itself ultimately play a vital role in its success and impact the whole system.