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Article
Publication date: 1 March 2005

Francisco Jurado and José Carpio

This paper describes models of micro‐turbines and fuel cells, which can be used in stability studies.

1618

Abstract

Purpose

This paper describes models of micro‐turbines and fuel cells, which can be used in stability studies.

Design/methodology/approach

The plants models derived are based on the main equations. These models are developed in the Laplace domain and transient simulation is done using a software developed based on the MATLAB package.

Findings

The micro‐source is capable of providing effective load‐following service in the distribution system. However, the results also show that the micro‐source is not an uninterruptible power supply and does not protect the load from voltage instability while in grid‐connect mode. When a micro‐turbine plant is connected to a point where it gives support to a load in fault conditions, the lower the inertia of micro‐turbine plant, the greater is the destabilizing tendency for faults in the distribution system. On the other hand, transient stability is enhanced with aid of the SOFC inverter.

Originality/value

The effects of these micro‐sources on the network performance are shown and a distribution system embedded with the micro‐sources is used as an example. Finally, transient stability and voltage stability of the system are investigated.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 24 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 June 2004

Francisco Jurado and José Ramón Saenz

This paper presents method to discriminate between transient voltage stability and voltage sag. The discrete wavelet transform (WT) is a powerful tool in the analysis of the…

592

Abstract

This paper presents method to discriminate between transient voltage stability and voltage sag. The discrete wavelet transform (WT) is a powerful tool in the analysis of the transient phenomena in power systems because of its ability to extract information in both the time and frequency domain. This paper introduces a technique for accurate discrimination by combining WTs with neural networks (NNs). The WT is first applied to decompose the signals into a series of detailed wavelet components. The wavelet components are calculated and then employed to train a NN. The simulated results presented clearly show that the proposed technique can accurately discriminate between transient voltage stability and voltage sag in power system protection.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 23 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Available. Open Access. Open Access
Article
Publication date: 23 March 2022

María Zamarreño Suárez, Rosa María Arnaldo Valdés, Francisco Pérez Moreno, Raquel Delgado-Aguilera Jurado, Patricia María López de Frutos and Víctor Fernando Gómez Comendador

Air traffic controllers (ATCOs) play a fundamental role in the safe, orderly and efficient management of air traffic. In the interests of improving safety, it would be beneficial…

1220

Abstract

Purpose

Air traffic controllers (ATCOs) play a fundamental role in the safe, orderly and efficient management of air traffic. In the interests of improving safety, it would be beneficial to know what the workload thresholds are that permit ATCOs to carry out their functions safely and efficiently. The purpose of this paper is to present the development of a simulation platform to be able to validate an affective-cognitive performance methodology based on neurophysiological factors applied to ATCOs, to define the said thresholds.

Design/methodology/approach

The process followed in setting up the simulation platform is explained, with particular emphasis on the design of the program of exercises. The tools designed to obtain additional information on the actions of ATCOs and how their workload will be evaluated are also explained.

Findings

To establish the desired methodology, a series of exercises has been designed to be simulated. This paper describes the project development framework and validates it, taking preliminary results as a reference. The validation of the framework justifies further study to extend the preliminary results.

Research limitations/implications

This paper describes the first part of the project only, i.e. the definition of the problem and a proposed methodology to arrive at a workable solution. Further work will concentrate on carrying out a program of simulations and subsequent detailed analysis of the data obtained, based on the conclusions drawn from the preliminary results presented.

Originality/value

The methodology will be an important tool from the point of view of safety and the work carried out by ATCOs. This first phase is crucial as it provides a solid foundation for later stages.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 9
Type: Research Article
ISSN: 1748-8842

Keywords

Available. Open Access. Open Access
Article
Publication date: 20 January 2022

Francisco Pérez Moreno, Víctor Fernando Gómez Comendador, Raquel Delgado-Aguilera Jurado, María Zamarreño Suárez, Dominik Janisch and Rosa María Arnaldo Valdes

The purpose of this paper is to set out a methodology for characterising the complexity of air traffic control (ATC) sectors based on individual operations. This machine learning…

939

Abstract

Purpose

The purpose of this paper is to set out a methodology for characterising the complexity of air traffic control (ATC) sectors based on individual operations. This machine learning methodology also learns from the data on which the model is based.

Design/methodology/approach

The methodology comprises three steps. Firstly, a statistical analysis of individual operations is carried out using elementary or initial variables, and these are combined using machine learning. Secondly, based on the initial statistical analysis and using machine learning techniques, the impact of air traffic flows on an ATC sector are determined. The last step is to calculate the complexity of the ATC sector based on the impact of its air traffic flows.

Findings

The results obtained are logical from an operational point of view and are easy to interpret. The classification of ATC sectors based on complexity is quite accurate.

Research limitations/implications

The methodology is in its preliminary phase and has been tested with very little data. Further refinement is required.

Originality/value

The methodology can be of significant value to ATC in that when applied to real cases, ATC will be able to anticipate the complexity of the airspace and optimise its resources accordingly.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 9
Type: Research Article
ISSN: 1748-8842

Keywords

Available. Open Access. Open Access
Article
Publication date: 7 April 2022

Raquel Delgado-Aguilera Jurado, Victor Fernando Gómez Comendador, María Zamarreño Suárez, Francisco Pérez Moreno, Christian Eduardo Verdonk Gallego and Rosa María Arnaldo Valdes

The purpose of this study is to establish a systematic framework to characterise the safety of air routes, in terms of separation minima infringements (SMIs) between en-route…

1048

Abstract

Purpose

The purpose of this study is to establish a systematic framework to characterise the safety of air routes, in terms of separation minima infringements (SMIs) between en-route aircraft, based on the definition of models known as safety performance functions.

Design/methodology/approach

Techniques with high predictive capability were selected that enable both expert knowledge and data to be harnessed: Bayesian networks. It was necessary to establish a conceptual framework that integrates the knowledge currently available on the causality and precursors of SMIs with the hindsight derived from the analysis of the type of data available. To translate the conceptual framework into a set of causal subnets, the concepts of air traffic management (ATM) barrier model and event trees have been incorporated.

Findings

The model combines analytics and insights, as well as predictive capability, to answer the question of how airspace separation infringements are produced and what their frequency of occurrence will be. The main outputs of the network are the predicted probability of success for the ATM barriers and the predicted probability distribution of the vertical and horizontal separation of an aircraft in its closest point of approach.

Originality/value

The main contribution of this work is that, by virtue of the calculation capacity obtained, the network can be used to draw conclusions about the impact that a modification of the airspace and of the traffic, or operational conditions, would have on the effectiveness of the barriers and on the final distributions of distance between aircraft in the CPA, thereby estimating the probability of SMI.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 9
Type: Research Article
ISSN: 1748-8842

Keywords

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Book part
Publication date: 1 June 2018

Teresa Jurado-Guerrero, Jordi M. Monferrer, Carmen Botía-Morillas and Francisco Abril

Most studies on work–life support at workplaces consider work–life balance to be a women’s issue, either explicitly or implicitly. This chapter analyses how fathers who are…

Abstract

Most studies on work–life support at workplaces consider work–life balance to be a women’s issue, either explicitly or implicitly. This chapter analyses how fathers who are involved caregivers are supported or hindered in attaining work–life balance by their workplaces. It explores the following three questions: (1) why fathers value some job adaptations over others compared with mothers; (2) how organizational cultures influence the work–life balance of new fathers and (3) what differences exist across public and private sectors as well as large versus small companies. A qualitative approach with three discussion groups and 22 involved fathers enables us to explore these issues for large companies, public sector workplaces and small businesses. We find that tight time schedules, flextime, telework, schedule control and fully paid nontransferable leaves of absence constitute policies that favor involved fatherhood, while measures without wage replacement generate fear of penalization in the workplace and do not fit the persistent relevance of the provider role. In addition, un-similar supervisors, envy, lack of understanding and gender stereotypes among co-workers and clients constitute cultural barriers at the workplace level. Contrary to our expectations, small businesses may offer a better work–life balance than large companies, while the public sector is not always as family-friendly as assumed.

Details

Fathers, Childcare and Work: Cultures, Practices and Policies
Type: Book
ISBN: 978-1-78743-042-6

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Article
Publication date: 10 August 2023

M.Teresa Gil-Muñoz and Félix Lasheras-Merino

Rising damp affects the deterioration and conservation of architectural heritage. Air cavities built next to the base of these buildings on an unsaturated floor can reduce the…

14

Abstract

Purpose

Rising damp affects the deterioration and conservation of architectural heritage. Air cavities built next to the base of these buildings on an unsaturated floor can reduce the damage to foundations and walls due to this. These are passive systems, which are usually designed with no objective data to show their functioning and effectiveness. This is why the authors are presenting this study.

Design/methodology/approach

This study is presented starting with simple field equipment for representative types for a previous cataloguing of cases in Spain. The physical parameters of the air in this research are air speed and evaporation in the cavities and the base, taking the local climate and the particular formal and construction characteristics of each case study as a reference.

Findings

The results of the analysis validate the method and the efficiency of such cavities, whose performance is greater in systems with a variety of features, that is to say, those which work by thermal or wind flow rather than those which only use hygric flow.

Originality/value

This work is novel because there are not in situ experimental works which prove the functioning and effectiveness of these systems.

Details

Journal of Cultural Heritage Management and Sustainable Development, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2044-1266

Keywords

Available. Open Access. Open Access
Article
Publication date: 25 November 2024

Francisco Muñoz-Leiva, Doaa Herzallah, Ismael Ramón Sánchez-Borrego and Francisco Liébana-Cabanillas

This study examines the role of logotypes in advertising effectiveness on s-commerce platforms by analyzing the visual attention paid by the consumer to fashion branding �…

249

Abstract

Purpose

This study examines the role of logotypes in advertising effectiveness on s-commerce platforms by analyzing the visual attention paid by the consumer to fashion branding – wordmarks or combination marks – and their subsequent recall.

Design/methodology/approach

The study examines the main areas of visual representation of the brand (VRB) on the Instagram network and the user’s corresponding areas of interest on a mobile-device screen. Attention and recall of the VRB are assessed in light of different classification variables (users’ gender, age and level of experience in s-commerce tools) to better understand how VRB may be leveraged by fashion retailers to encourage purchasing behavior. To achieve this objective, a mixed experiment design based on the eye-tracking methodology and a self-administered questionnaire is carried out.

Findings

The results indicate that visual attention, gender, age and s-commerce experience all contribute to determining users’ recall of the brand logo to which they are exposed on-screen. By considering the different s-commerce user profiles that exhibit different visualization behaviors, fashion retailers will be better placed to improve their online advertising campaigns and, ultimately, increase brand sales. The findings also point to promising future research directions on the effectiveness of branding strategies.

Originality/value

This highly innovative study provides in-depth insights into advertising effectiveness in terms of attention and recall, according to the main types of VRB for two specific s-commerce tools used by a high-street fashion brand, namely, its profile on Instagram Shop and its profile on Instagram Stories.

Details

European Journal of Management and Business Economics, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2444-8451

Keywords

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Abstract

Details

Fathers, Childcare and Work: Cultures, Practices and Policies
Type: Book
ISBN: 978-1-78743-042-6

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Article
Publication date: 2 March 2022

Francisco Elânio Bezerra, Flavio Grassi, Cleber Gustavo Dias and Fabio Henrique Pereira

This paper aims to propose an approach based upon the principal component analysis (PCA) to define a contribution rate for each variable and then select the main variables as…

116

Abstract

Purpose

This paper aims to propose an approach based upon the principal component analysis (PCA) to define a contribution rate for each variable and then select the main variables as inputs to a neural network for energy load forecasting in the region southeastern Brazil.

Design/methodology/approach

The proposed approach defines a contribution rate of each variable as a weighted sum of the inner product between the variable and each principal component. So, the contribution rate is used for selecting the most important features of 27 variables and 6,815 electricity data for a multilayer perceptron network backpropagation prediction model. Several tests, starting from the most significant variable as input, and adding the next most significant variable and so on, are accomplished to predict energy load (GWh). The Kaiser–Meyer–Olkin and Bartlett sphericity tests were used to verify the overall consistency of the data for factor analysis.

Findings

Although energy load forecasting is an area for which databases with tens or hundreds of variables are available, the approach could select only six variables that contribute more than 85% for the model. While the contribution rates of the variables of the plants, plus energy exchange added, have only 14.14% of contribution, the variable the stored energy has a contribution rate of 26.31% being fundamental for the prediction accuracy.

Originality/value

Besides improving the forecasting accuracy and providing a faster predictor, the proposed PCA-based approach for calculating the contribution rate of input variables providing a better understanding of the underlying process that generated the data, which is fundamental to the Brazilian reality due to the accentuated climatic and economic variations.

Details

International Journal of Energy Sector Management, vol. 16 no. 6
Type: Research Article
ISSN: 1750-6220

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