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Article
Publication date: 15 December 2020

Francisco Villarreal-Valderrama, Carlos Santana Delgado, Patricia Del Carmen Zambrano-Robledo and Luis Amezquita-Brooks

Reducing fuel consumption of unmanned aerial vehicles (UAVs) during transient operation is a cornerstone to achieve environment-friendly operations. The purpose of this paper is…

332

Abstract

Purpose

Reducing fuel consumption of unmanned aerial vehicles (UAVs) during transient operation is a cornerstone to achieve environment-friendly operations. The purpose of this paper is to develop a control scheme that improves the fuel economy of a turbojet in its full operating envelope.

Design/methodology/approach

A novel direct-thrust linear quadratic integral (LQI) approach, comprised by an optimal observer/controller satisfying specified performance parameters, is presented. The thrust estimator, based in a Wiener model, is validated with the experimental data of a micro-turbojet. Model uncertainty is characterized by analyzing variations between the identified model and measured data. The resulting uncertainty range is used to verify closed-loop stability with the circle criterion. The proposed controller provides stable responses with the specified performance in the whole operating range, even with after considering plant nonlinearities. Finally, the direct-thrust LQI is compared with a standard thrust controller to assess fuel economy and performance.

Findings

The direct-thrust LQI approach reduced the fuel consumption by 2.1090% in the most realistic scenario. The controllers were also evaluated using the environmental effect parameter (EEP) and transient-thrust-specific fuel consumption (T-TSFC). These novel metrics are proposed to evaluate the environmental impact during transient-thrust operations. The direct-thrust LQI approach has a more efficient fuel consumption according to these metrics. The results also show that isolating the thrust dynamics within the feedback loop has an important impact in fuel economy. Controllers were also evaluated using the EEP and T-TSFC. These novel metrics are proposed to evaluate the environmental impact during transient-thrust operations. The direct-thrust LQI approach has a more efficient fuel consumption according to these metrics. The results also show that isolating the thrust dynamics within the feedback loop has an important impact in fuel economy.

Originality/value

This study shows the design of an effective direct-thrust control approach that minimizes fuel consumption, ensures stable responses for the full operation range, allows isolating the thrust dynamics when designing the controller and is compatible with classical robustness and performance metrics. Finally, the study shows that a simple controller can reduce the fuel consumption of the turbojet during transient operation in scenarios that approximate realistic operating conditions.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 3
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 18 June 2024

Ava Santana Barbosa, Joanna Carneiro Delgado, Letícia Conceição Quintela de Alcântara, Carlos Jefferson de Melo Santos and Angelo Marcio Oliveira Sant’Anna

This paper aims to propose a framework to assess the readiness of Brazilian small and medium service companies to use Industry 4.0 technologies to improve the efficiency of…

175

Abstract

Purpose

This paper aims to propose a framework to assess the readiness of Brazilian small and medium service companies to use Industry 4.0 technologies to improve the efficiency of processes, reinforcing the idea that evaluating and planning the implementation is as important as the use, without the need for big investments.

Design/methodology/approach

The paper presents two applications on the readiness level of small and medium enterprises, with support from researchers and stakeholders. The literature seems to focus more on the maturity level than on providing a sequence of operational steps or decision support. It would lead to better implementation of I4.0 technologies in assessing the company’s readiness level to adopt them.

Findings

The authors analyze the relevant case studies in Brazilian small and medium service enterprises based on the proposed framework to investigate the main challenges and hardships for Industry 4.0 readiness in the current scenario and outline directions to increase their readiness for adopting key Industry 4.0 technologies. Moreover, the case studies consolidate a fundamental advantage to small and medium enterprise service: a guided implementation provides more knowledge about products, processes and I4.0 technologies, even in unsuccessful case studies.

Practical implications

The need was identified when studying market trends with the digital transformation provided by Industry 4.0 technologies and, in parallel, the difficulties of small and medium service companies in adapting to this new scenario. Through the proposed framework, an action plan can be drawn up with well-defined objectives, goals and activities so that the service enterprises can increase their Industry 4.0 readiness level within three months.

Originality/value

A relevant aspect is that this study is based on feedback from stakeholders and managers, which makes the analyses and conclusions from empirical points of view without relevant theoretical knowledge of the relationship between I4.0 technologies. Therefore, the proposed framework made it possible to diagnose the organization’s external and internal environments, allowing the ideal condition and the current situation of the companies to be compared, as argued in the Industry 4.0 readiness literature review.

Details

International Journal of Lean Six Sigma, vol. 16 no. 2
Type: Research Article
ISSN: 2040-4166

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Book part
Publication date: 30 December 2013

Salvador Anton Clavé

This chapter reflects upon the trajectory of research in the geography of tourism in Spain. It begins with a review, including the evolution of the main topics present in the…

Abstract

This chapter reflects upon the trajectory of research in the geography of tourism in Spain. It begins with a review, including the evolution of the main topics present in the subdiscipline, with a special focus on developments since the 1990s. This is followed by an analysis of the current role and potential impact of academic tourism geography and a discussion on the recent growth in the publication of research results in international journals. Of importance are the institutional factors that explain the increasing recognition of research on the geography of tourism in Spain. Finally, the chapter discusses the hegemony of positivist approaches pivoting on land use, local and regional development, impact analysis, and landscape transformation, as well as the emerging links between Spanish tourism geography and the international mainstream schools of thought.

Details

Geographies of Tourism
Type: Book
ISBN: 978-1-78190-212-7

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Article
Publication date: 21 April 2020

Jorge Andrés Muñoz Mendoza, Sandra María Sepúlveda Yelpo, Carmen Lissette Velosos Ramos and Carlos Leandro Delgado Fuentealba

The purpose of this article is to analyze the effects of financing policy and countries' institutional–financial characteristics on earnings management (EM) practices in Latin…

648

Abstract

Purpose

The purpose of this article is to analyze the effects of financing policy and countries' institutional–financial characteristics on earnings management (EM) practices in Latin American companies.

Design/methodology/approach

The GMM estimator was used according to Arellano and Bover (1995) for panel data on a sample of 983 Latin American companies between 1995 and 2017.

Findings

Leverage and short-term debt have a negative and nonlinear effect on EM practices. Nonlinearity suggests that firms with high levels of leverage and short-term debt carry out positive discretionary accruals. Countries' institutional and financial development reduces EM practices. Mandatory IFRS adoption also reduces these practices and mitigates the effects of the low institutional and financial development on EM.

Originality/value

These results reveal the relevance of companies' financing policy as a means of controlling EM practices. Results also suggest that policy effectiveness decreases with leverage and short-term debt. It is suggested that policymakers design financial policies aimed to promote institutional and financial development as a means of systematic control over EM activities, which also includes IFRS.

Details

International Journal of Emerging Markets, vol. 16 no. 3
Type: Research Article
ISSN: 1746-8809

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Article
Publication date: 21 January 2021

Jorge Andrés Muñoz Mendoza, Carmen Lissette Veloso Ramos, Sandra María Sepúlveda Yelpo, Carlos Leandro Delgado Fuentealba and Rodrigo Alberto Fuentes-Solís

The purpose of this article is to analyze the effects of accruals-based earnings management (AEM), International Financial Reporting Standard (IFRS) adoption and stock market…

614

Abstract

Purpose

The purpose of this article is to analyze the effects of accruals-based earnings management (AEM), International Financial Reporting Standard (IFRS) adoption and stock market integration for firms that belong to Latin-American Integrated Market (MILA).

Design/methodology/approach

The GMM estimator was used according to Arellano and Bover (1995) for panel data on a sample of 478 non-financial companies between 2000 and 2016. Multilevel mixed models was used for the robustness analysis.

Findings

AEM practices significantly and dynamically reduce agency costs. This result suggests companies use positive discretionary accruals to hide true agency costs and avoid shareholders monitoring, while negative discretionary accruals are ways to expropriate wealth and increase agency costs. This result implies that firms use AEM as a predetermined strategy to weaken corporate governance. The IFRS adoption and MILA implementation reduced agency costs. However, only IFRS adoption had the capability to mitigate the effects of AEM on agency costs.

Originality/value

These results reveal AEM constitutes a practice that managers use to weaken firms’ corporate governance and expropriate wealth from shareholders. These practices have effects at short-run and long-run. However, the IFRS adoption and market integration represented by MILA are mitigating factors for agency costs. These results have relevant implications for firms’ corporate governance because they guide investors and shareholders to strengthen corporate control and monitoring on business decision-making. These results also are relevant to policymakers because they orient the financial policies design to strengthen the benefits of IFRS and MILA.

Details

Baltic Journal of Management, vol. 16 no. 2
Type: Research Article
ISSN: 1746-5265

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Article
Publication date: 20 February 2023

Jorge Andrés Muñoz Mendoza, Carmen Lissette Veloso Ramos, Sandra María Sepúlveda Yelpo, Carlos Leandro Delgado Fuentealba and Edinson Edgardo Cornejo-Saavedra

The purpose of this article is to analyze the effects of accruals-based earnings management (AEM) and institutional and financial development on corporate risk of Latin-American…

346

Abstract

Purpose

The purpose of this article is to analyze the effects of accruals-based earnings management (AEM) and institutional and financial development on corporate risk of Latin-American firms.

Design/methodology/approach

The GMM estimator was used according to Arellano and Bond (1991) for panel data on a sample of 914 non-financial companies between 2005 and 2017.

Findings

AEM practices significantly increase corporate risk. This result indicates that the risk increase is associated to weakening of the corporate governance of companies. Positive discretionary accruals also have the same impact on corporate risk. In addition, accrual-based earnings management has a non-linear impact on corporate risk. Higher institutional and financial development systemically reduces the risk of Latin American firms. Institutional development can mitigate the effects of earnings management on corporate risk.

Originality/value

These results support that AEM represents a practice that managers use to weaken firms' corporate governance and expropriate wealth from shareholders. These practices promote higher firm's risk. However, the institutional and financial development reduces the corporate risk and contributes to mitigate the impact of AEM on it. These results have relevant implications for firms' corporate governance because they warn the relevance to control AEM practices and its impact over corporate risk perception by investors. These results also are relevant to policymakers because they orient the financial policies design to strengthen the institutional and financial development as a systematic way to reduce the firm's risk.

Objetivo

El propósito de este artículo es analizar los efectos de la gestión de ganancias basada en devengos (AEM) y el desarrollo institucional y financiero sobre el riesgo corporativo de las empresas latinoamericanas.

Diseño/metodología/enfoque

Se utilizó el estimador GMM de Arellano y Bond (1991) sobre una muestra de 914 empresas no financieras entre 2005 y 2017.

Hallazgos

Las prácticas de AEM aumentan significativamente el riesgo corporativo. Este resultado indica que el aumento del riesgo está asociado al debilitamiento del gobierno corporativo de las empresas. Los devengos discrecionales positivos también tienen el mismo impacto en el riesgo corporativo. Además, la gestión de ganancias basada en el devengo tiene un impacto no lineal sobre el riesgo. Un mayor desarrollo institucional y financiero reduce sistémicamente el riesgo de las empresas. El desarrollo institucional puede mitigar los efectos de la gestión de ganancias sobre el riesgo corporativo.

Originalidad/valor

Estos resultados revelan que AEM es una práctica que debilita los gobiernos corporativos y permite expropiar riqueza de los accionistas. Estas prácticas promueven un mayor riesgo corporativo, aunque el desarrollo institucional y financiero lo reduce. Estos resultados tienen implicancias relevantes para el gobierno corporativo de las empresas porque indican la relevancia de controlar estas prácticas en la percepción de riesgo de los inversionistas. Estos resultados también son relevantes para los reguladores porque orientan el diseño de políticas financieras hacia el fortalecimiento del desarrollo institucional y financiero como una vía sistemática que reduce el riesgo de las empresas.

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Book part
Publication date: 30 December 2013

Julie Wilson and Salvador Anton Clavé

Abstract

Details

Geographies of Tourism
Type: Book
ISBN: 978-1-78190-212-7

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Book part
Publication date: 30 December 2013

Jarkko Saarinen

Travel and tourism have had a long history in the Nordic countries, but research on tourism has a relatively short tradition in the region. Recently, academic interest in the…

Abstract

Travel and tourism have had a long history in the Nordic countries, but research on tourism has a relatively short tradition in the region. Recently, academic interest in the Nordic tourism space has grown and diversified especially as a result of increasing numbers of academics and institutions involved with tourism geographies and studies and education in the region. The Nordic context has provided thematic focus areas for empirical studies that characterize tourism geographies in the region, with topics including nature-based tourism, utilization of wilderness areas, second-home and rural developments, impacts in peripheries, and tourism as a tool for regional development. In addition, there are emerging research themes outside of the traditional core topics, such as urban, events, and heritage tourism.

Details

Geographies of Tourism
Type: Book
ISBN: 978-1-78190-212-7

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Book part
Publication date: 30 December 2013

Nicolai Scherle and Hans Hopfinger

This chapter aims to familiarize the reader with some of the important aspects of tourism geography in the German-speaking countries. It starts with a primarily historical-genetic…

Abstract

This chapter aims to familiarize the reader with some of the important aspects of tourism geography in the German-speaking countries. It starts with a primarily historical-genetic perspective on tourism development and the theoretical traditions associated with them. The second section describes the structure of the discipline, with a focus on the institutionalization of the field in the universities including their research specialization. The chapter maintains that tourism geography plays a marginal role compared with other subdisciplines of geography, though this is reflected primarily in its institutionalization and less so in the research undertaken. The last section deals with the current challenges and future prospects in German-speaking geographies of tourism from a problem-centered perspective.

Details

Geographies of Tourism
Type: Book
ISBN: 978-1-78190-212-7

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Book part
Publication date: 30 December 2013

Alessia Mariotti

This chapter discusses the main research interests and outputs in the various branches of geography that have influenced the study of tourism from a geographical perspective. It…

Abstract

This chapter discusses the main research interests and outputs in the various branches of geography that have influenced the study of tourism from a geographical perspective. It argues that the idiographic tradition has been transversal throughout, leading to the growing interest for tourism within the geography academic community in the last 10 years. There is a focus on the birth of specific research groups, mainly related to a constellation of new university curricula on tourism and—with few exceptions of territorial tradition—to an intermittent availability of public research funds. The chapter concludes with a more general picture of the place of tourism within the geography discipline in Italy and of evolving trends in terms of research results, dissemination, and evaluation.

Details

Geographies of Tourism
Type: Book
ISBN: 978-1-78190-212-7

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