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1 – 4 of 4Alfonso Parreño Torres, Pedro Roncero‐Sánchez, Xavier del Toro García and Vicente Feliu Batlle
The protection of sensitive loads connected to power distribution grids from the existing disturbances has become an important issue in recent years. This paper aims to evaluate…
Abstract
Purpose
The protection of sensitive loads connected to power distribution grids from the existing disturbances has become an important issue in recent years. This paper aims to evaluate the advantages of a new control strategy, known as the generalized proportional‐integral (GPI) control, to compensate voltage sags when using dynamic voltage restorers (DVR).
Design/methodology/approach
The DVR application and the principles of the GPI control method are first introduced. In addition, a procedure to adjust the controller for the DVR application is described. Finally, the performance of the controller is extensively tested using the PSCAD/EMTDC simulation software for a variety of conditions including: balanced and imbalanced voltage sags, frequency deviations and parameter variations.
Findings
The GPI controller provides an excellent tradeoff between accuracy, response time and robustness.
Originality/value
The GPI controller is presented here as a new approach to compensate balanced and imbalanced voltage sags using a DVR. The results obtained with the proposed control system and the described methodology to adjust the control parameters make it a very suitable solution for this application. It is important to note that fast tracking and high accuracy are achieved as illustrated in the control responses. Furthermore, the analysis of the robustness against parameter variations and frequency deviations demonstrates one of the most remarkable advantages of the new control method.
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Ferrante Neri, Xavier del Toro Garcia, Giuseppe L. Cascella and Nadia Salvatore
This paper aims to propose a reliable local search algorithm having steepest descent pivot rule for computationally expensive optimization problems. In particular, an application…
Abstract
Purpose
This paper aims to propose a reliable local search algorithm having steepest descent pivot rule for computationally expensive optimization problems. In particular, an application to the design of Permanent Magnet Synchronous Motor (PMSM) drives is shown.
Design/methodology/approach
A surrogate assisted Hooke‐Jeeves algorithm (SAHJA) is proposed. The SAHJA is a local search algorithm with the structure of the Hooke‐Jeeves algorithm, which employs a local surrogate model dynamically constructed during the exploratory move at each step of the optimization process.
Findings
Several numerical experiments have been designed. These experiments are carried out both on the simulation model (off‐line) and at the actual plant (on‐line). Moreover, the off‐line experiments have been considered in non‐noisy and noisy cases. The numerical results show that use of the SAHJA leads to a saving in terms of computational cost without requiring any extra hardware components.
Originality/value
The surrogate approach in the design of electric drives is novel. In addition, implementation of the proposed surrogate model allows the algorithm not only to reduce computational cost but also to filter noise caused by the sensors and measurement devices.
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Raquel Chafloque-Cespedes, Aldo Alvarez-Risco, Paula-Viviana Robayo-Acuña, Carlos-Antonio Gamarra-Chavez, Gabriel-Mauricio Martinez-Toro and Wagner Vicente-Ramos
This chapter is designed with the aim to determine the influence of sociodemographic variables on the capacity to generate social enterprises, such as sex, the student’s country…
Abstract
This chapter is designed with the aim to determine the influence of sociodemographic variables on the capacity to generate social enterprises, such as sex, the student’s country, if only they study or if they study and work, as well as if they participate or direct a social enterprise in university students of Latin American business schools. This research adopted an inductive quantitative approach using a questionnaire. The participants were university students of business schools from Colombia, Mexico and Peru. Second-generation structural equation method (SEM-PLS) was used to analyse the results, using the SmartPLS 3.2.7 software applied to data on 3,739 university students. The results suggest that the entrepreneur role, labour situation, country and sex have a moderating effect in the relation between entrepreneurial orientation and entrepreneurial intention. Also, by using resampling technique Bootstrapping (5,000 times,p < 0.01), significance of the trajectory coefficients (beta) and effect size of the coefficients (beta) were measured to demonstrate significance. Finally, with this research the authors ascertain that entrepreneurial orientation positively influences entrepreneurial intention. thus explaining 42.4% of its variance. This chapter is the first attempt on investigating in university students of Latin American business schools about factors of entrepreneurship orientation and entrepreneurship intention, and has strong potential to contribute to development of policies and strategies to promote the growth of entrepreneurship activities in the universities.
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Juan Felipe Parra, Alejandro Valencia-Arias and Jonathan Bermúdez-Hernández
Entrepreneurial intention is one of the main predictors of venture creation. However, the approaches used to analyze the entrepreneurial intention and venture creation are mostly…
Abstract
Purpose
Entrepreneurial intention is one of the main predictors of venture creation. However, the approaches used to analyze the entrepreneurial intention and venture creation are mostly linear approaches, leaving aside the fact that new ventures arise in a context characterized by fluctuations and instability, especially in emerging economies where economic and social factors are highly variables. Nevertheless, a dynamic approach could best represent its behavior. This study aims to propose an alternative approach and a starting point for more complex dynamic models in the entrepreneurship process that surpass the limitation of the current linear methodologies and allow gathering isolated studies' contributions.
Design/methodology/approach
This study proposes a method to shed light on the processes related to the venture creation process and entrepreneurial intention by designing a system dynamics simulation model.
Findings
The results reveal that the delayed effect of expectations produces a growing tendency in project creation, venture establishment and venture creation. Likewise, the entrepreneurial intention is not a static variable; it changes by the system’s dynamics and disturbs the venture creation process, which produces an increase in oscillations in the model and, therefore, reduces the project’s growth and venture creation.
Research limitations/implications
This model is a generic approach for the study of venture creation and entrepreneurial intention. The model can analyze entrepreneurial intention and venture creation in different contexts, adjusting the different model parameters. The authors run a sensitivity analysis to encompass deviation from the parameter established and the uncertainty about them. However, the empirical data used for the model’s testing, in this case, correspond to an approximation to the behavior of venture creation in Colombia, which is considered an emerging economy. The model proposed does not pretend to incorporate all the variables and phenomena about entrepreneurship.
Originality/value
The approach suggested in this work aims to conceptualize venture creation as a complex process that emerges from the occurrence and combination of simpler states, instead of activities that represent building blocks. In addition, the term “entrepreneurial process” is defined as a composite of different perspectives that use a series of multidisciplinary theories to address the topic.
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