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Article
Publication date: 23 August 2011

Antonio Gonzalez Rodriguez, Angel Gonzalez Rodriguez and Pierluigi Rea

The paper aims to present a new mechanical scheme for a leg to be included in legged vehicles that simplifies the control actuations along the stride.

Abstract

Purpose

The paper aims to present a new mechanical scheme for a leg to be included in legged vehicles that simplifies the control actuations along the stride.

Design/methodology/approach

The scheme includes three four‐bar links grouped in two mechanisms. The first one decouples the vertical and horizontal foot movements. The second one produces a constant horizontal foot velocity when the corresponding motor is given a constant speed. A hybrid robot with wheels at the end of the hind legs has been simulated and constructed to validate the leg performance.

Findings

The gait control requires only five commands for the electronic cards to control the leg. Decoupling vertical and horizontal movements allows a more adequate selection of actuators, a reduction of energy consumption, and higher load capacity and robot velocity. Additional mechanical benefits, such as improved robustness and lower inertia, are obtained. The hind legs can also be articulated, allowing the robot to overcome an obstacle and to climb up and down stairs.

Research limitations/implications

A hybrid robot offers greater stability with respect to a legged robot. This way the lateral movement is not a concern, and therefore it has not been tested yet during the walking cycle.

Originality/value

This new scheme obtains a quasi‐Cartesian behaviour for the foot movement that drastically simplifies the control of the walking cycle. Although the decoupling between movements has already been obtained in previous configurations, these follow a pantograph structure and suffer from blocking problems when they are subject to lateral forces. These schemes were suitable for crab‐like gaits. The proposed leg moves according to a mammal‐like gait.

Details

Industrial Robot: An International Journal, vol. 38 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 9 January 2009

Antonio Gonzalez Rodriguez, Nestor Eduardo Nava Rodriguez and Angel Gaspar Gonzalez Rodriguez

The purpose of this paper is to propose a novel actuator with adaptable compliance for robotic applications.

Abstract

Purpose

The purpose of this paper is to propose a novel actuator with adaptable compliance for robotic applications.

Design/methodology/approach

In order to achieve limb actuation similar to that of human muscles, a novel actuator with adaptable compliance is proposed. Three principal design paradigms currently exist in the development of artificial muscles that have been adopted at several research centres, universities and commercial organizations around the world. The first approach consists of using compliant actuator systems such as pneumatic actuators. The second approach undertakes the development of electroactive polymers that deform when a voltage is applied. The third approach involves electromechanical devices typically comprising an electrical actuator and an elastic element in combination. The proposed actuator extends on the third approach. It comprises an electrical DC motor in serial configuration and a novel elastic device exhibiting variable stiffness.

Findings

The novel elastic device complements the mechanical structure of the device, enabling adaptation to the dynamic effects of external forces.

Practical implications

Several applications for the actuator with adaptable compliance have been identified in the field of human‐like robotics.

Originality/value

Prototypic experimentation has successfully demonstrated the variable stiffness of the device.

Details

Industrial Robot: An International Journal, vol. 36 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 June 2021

Gracia Rubio Martín, Conrado Miguel Manuel García, Ángel Rodríguez-López and Francisco José Gonzalez Sanchez

This research proposes analytical valuation models throughout football players' life cycles based on crowd valuations from social media to produce dynamic sporting human…

Abstract

Purpose

This research proposes analytical valuation models throughout football players' life cycles based on crowd valuations from social media to produce dynamic sporting human capital disclosures, and therefore, supplying further useful information to capture the intellectual capital (IC) of football clubs.

Design/methodology/approach

This work is carried out using an econometric model that includes 658 observations of crowd judgments versus their transfer fees, for the best footballers of the three major European Leagues between 2006 and 2018. To make the model more parsimonious, the set of independent variables that really add value has been found across the stepwise methodology.

Findings

The significant differences between both models are analyzed, integrating previous academic literature based on the existence of negotiation elements in prices, and in the capacity of crowdsourcing to explain assessments of football players, from a dynamic perspective, alongside a new variable: injuries, which has not been explained before.

Originality/value

The broader assessments from crowdsourcing should be integrated in intellectual capital disclosures (ICD), from a critical, novel and dynamic perspective, creating a virtuous cycle between managers and fans, to increase transparency of financial information for stakeholders and society.

Details

Journal of Intellectual Capital, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1469-1930

Keywords

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Book part
Publication date: 12 January 2021

Maria Victoria Whittingham

Uncertainty is one of the principal features of public administration in Colombia. Therefore, presenting a clear and consistent analysis is difficult. This uncertainty…

Abstract

Uncertainty is one of the principal features of public administration in Colombia. Therefore, presenting a clear and consistent analysis is difficult. This uncertainty exists alongside interesting efforts to modernize institutions. Among the challenges faced by public administration in Colombia, we find corruption, illegal bands of drug traffickers, and the lack of trust between critical actors involved in governance. The aim of this chapter is to share an analysis that illustrates the difficulties and contradictions faced by those working in the public sector.

“Colombia is a legal social state organized in the form of a unitary republic, decentralized, with the autonomy of its territorial units, democratic, participatory, and pluralistic, based on respect of human dignity, on the work and solidarity of the individuals who belong to it, and the predominance of the general interest” (National Constitution, 1st Article).

“Colombia is a legal social state organized in the form of a unitary republic, decentralized, with the autonomy of its territorial units, democratic, participatory, and pluralistic, based on respect of human dignity, on the work and solidarity of the individuals who belong to it, and the predominance of the general interest” (National Constitution, 1st Article).

Details

The Emerald Handbook of Public Administration in Latin America
Type: Book
ISBN: 978-1-83982-677-1

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Book part
Publication date: 4 September 2017

Ana Josefina Cuevas

This paper aims at a better understanding of contemporary women’s relationship paths and their reasoning behind them. Qualitative interviews with 48 rural and urban women…

Abstract

This paper aims at a better understanding of contemporary women’s relationship paths and their reasoning behind them. Qualitative interviews with 48 rural and urban women from Western Mexico were conducted and analyzed using a thematic approach and data discussed from a feminist, gender approach and late modernity approach. Findings reveal civil and religious marriages were the paths two-third of women followed to start a family and that women living in permanent and alternating cohabitation did not seek to marry. Women held ambivalent views on marital life and poorer and less-educated women, particularly urban participants, had no choice but to marry. Findings on reasoning reveal a more complex and diverse reality than previous sociodemographic studies have portrayed, where pragmatism and social order were the main causes for marrying and cohabitation. Narratives show premarital sex and the symbolism of marriage and family are changing. A comparative approach between contexts of study, age groups, civil status, and social strata enriched and strengthened the discussion of the findings. The results were contrasted with existing Mexican literature from different fields. A larger qualitative study is needed to broaden the scope of the findings made by this study, whilst large-scale studies should consider either the use of mixed approaches or the inclusion of items that allow them to identify the elements of social and cultural change. The study could help to demystify women’s attitudes toward marriage, sex, and love; a field currently sprinkled with western romantic love values and gender-driven idealizations. This paper might be of interest for social demographers, anthropologists, sociologists, and historians conducting research on these themes from feminist and gender perspectives.

Details

Intimate Relationships and Social Change
Type: Book
ISBN: 978-1-78714-610-5

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Book part
Publication date: 3 June 2020

Oscar Javier Montiel Méndez and María Guadalupe Calderón

The legitimacy of history: dictated Bloch. Today, in many areas of knowledge, and of course in entrepreneurship (Wadhwani, 2010), it has become superlative. The aim of…

Abstract

The legitimacy of history: dictated Bloch. Today, in many areas of knowledge, and of course in entrepreneurship (Wadhwani, 2010), it has become superlative. The aim of this chapter is analyzing the literature about entrepreneurship in Mexico mainly from the last 11 years of studies on the subject. Through this review, we want to highlight the progress in the field, as well as deeper opportunities in its research as a result of it, the profound need for incorporating them not only in the national academic debate but also into the entrepreneurship ecosystem and in specific public policies.

Details

The History of Entrepreneurship in Mexico
Type: Book
ISBN: 978-1-83909-172-8

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Article
Publication date: 27 January 2021

Miguel Ángel Caminero, Ana Romero, Jesús Miguel Chacón, Pedro José Núñez, Eustaquio García-Plaza and Gloria Patricia Rodríguez

Fused filament fabrication (FFF) technique using metal filled filaments in combination with debinding and sintering steps can be a cost-effective alternative for…

Abstract

Purpose

Fused filament fabrication (FFF) technique using metal filled filaments in combination with debinding and sintering steps can be a cost-effective alternative for laser-based powder bed fusion processes. The mechanical behaviour of FFF-metal materials is highly dependent on the processing parameters, filament quality and adjusted post-processing steps. In addition, the microstructural material properties and geometric characteristics are inherent to the manufacturing process. The purpose of this study is to characterize the mechanical and geometric performance of three-dimensional (3-D) printed FFF 316 L metal components manufactured by a low-cost desktop 3-D printer. The debinding and sintering processes are carried out using the BASF catalytic debinding process in combination with the BASF 316LX Ultrafuse filament. Special attention is paid on the effects of build orientation and printing strategy of the FFF-based technology on the tensile and geometric performance of the 3-D printed 316 L metal specimens.

Design/methodology/approach

This study uses a toolset of experimental analysis techniques [metallography and scanning electron microcope (SEM)] to characterize the effect of microstructure and defects on the material properties under tensile testing. Shrinkage and the resulting porosity of the 3-D printed 316 L stainless steel sintered samples are also analysed. The deformation behaviour is investigated for three different build orientations. The tensile test curves are further correlated with the damage surface using SEM images and metallographic sections to present grain deformation during the loading progress. Mechanical properties are directly compared to other works in the field and similar additive manufacturing (AM) and Metal Injection Moulding (MIM) manufacturing alternatives from the literature.

Findings

It has been shown that the effect of build orientation was of particular significance on the mechanical and geometric performance of FFF-metal 3-D printed samples. In particular, Flat and On-edge samples showed an average increase in tensile performance of 21.7% for the tensile strength, 65.1% for the tensile stiffness and 118.3% for maximum elongation at fracture compared to the Upright samples. Furthermore, it has been able to manufacture near-dense 316 L austenitic stainless steel components using FFF. These properties are comparable to those obtained by other metal conventional processes such as MIM process.

Originality/value

316L austenitic stainless steel components using FFF technology with a porosity lower than 2% were successfully manufactured. The presented study provides more information regarding the dependence of the mechanical, microstructural and geometric properties of FFF 316 L components on the build orientation and printing strategy.

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Article
Publication date: 29 July 2014

Inés Rueda Sampedro, Ana Fernández‐Laviada and Angel Herrero Crespo

Based on the Theory of Planned Behaviour, the purpose of this paper is to analyse the influence of the advantages and disadvantages of entrepreneurship surrounding the…

Abstract

Purpose

Based on the Theory of Planned Behaviour, the purpose of this paper is to analyse the influence of the advantages and disadvantages of entrepreneurship surrounding the entrepreneurial intention on a university context.

Design/methodology/approach

To test the hypothesis it is used a quantitative research. With a structural equations approach, it is explored the psychological mechanisms that could affect to the entrepreneurial intentions of university students.

Findings

The results obtained show that the advantages related to entrepreneurship, in particular personal rewards, influence positively on the entrepreneurial attitude. However, the disadvantages, in particular economic aspects, have a negative effect. Additionally, the authors test that the gender and the academic training have a moderate effect on the variables which influence on the entrepreneurial intention.

Originality/value

This paper contributes to the literature on entrepreneurship in two important aspects. First, it goes into detail about the influence that perceived advantages and disadvantages of starting a new business has on entrepreneurial intentions. Second, the authors examine relevant and special collective, university students that try to decide their professional future and, hence, it is a critical period to decide the startup of a new business.

Propósito

Con la Teoría de Comportamiento Planificado como marco de referencia este trabajo analiza la influencia de las ventajas e inconvenientes asociados al emprendimiento sobre la intención emprendedora en un contexto universitario.

Diseño/metodología

Para la contrastación empírica de las hipótesis planteadas se realiza una investigación de naturaleza cuantitativa mediante la cual se exploran los mecanismos psicológicos que podrían guiar las intenciones de emprendimiento de los estudiantes universitarios.

Resultados

Los resultados obtenidos ponen de manifiesto que las ventajas asociadas al emprendimiento, en especial las recompensas personales, influyen positivamente en la actitud emprendedora, mientras que los inconvenientes asociados al emprendimiento, y en particular los aspectos económicos, ejercen un efecto negativo. Asimismo, se constata que el sexo y los estudios cursados tienen un efecto moderador en las variables que afectan a la intención emprendedora.

Originalidad/Valor

El presente trabajo aporta dos contribuciones fundamentales a la literatura sobre emprendimiento. Por un lado, profundiza en la comprensión de la influencia que tienen en la decisión de emprender las percepciones de los individuos respecto a las ventajas e inconvenientes de crear un negocio propio. Por otro lado, se examina un colectivo de especial relevancia en el ámbito del emprendimiento, como son los estudiantes universitarios, que se encuentran en situación de encaminar su futuro profesional y, por tanto, en un momento crítico para la decisión de crear una empresa propia.

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Article
Publication date: 23 May 2018

Mariluz Fernandez-Alles, Juan Pablo Diánez-González, Tamara Rodríguez-González and Mercedes Villanueva-Flores

The purpose of this paper is to analyze potentially significant differences in a series of relevant characteristics of universities’ technology transfer offices (TTOs). To…

Abstract

Purpose

The purpose of this paper is to analyze potentially significant differences in a series of relevant characteristics of universities’ technology transfer offices (TTOs). To this end, TTOs have been classified by the function of their resources assigned to the enhancement of university entrepreneurship. The factors analyzed are the number of academic spin-offs created with the support of TTOs as well as the TTOs’ age, experience, professionalization and relational capital.

Design/methodology/approach

The authors have performed a hierarchical agglomerative cluster analysis to identify the groups of TTOs with homogeneous behavior and features. This multivariate technique allows determining whether it is possible to identify some differentiated conglomerates of TTOs.

Findings

The results of the cluster analysis allow concluding that the number of academic spin-offs created with the support of TTOs, the age and degree of professionalization of these TTOs, the experiences of their employees in matters related to entrepreneurship and their relationships with market actors explain the different levels of commitment of TTOs toward the enhancement of university entrepreneurship. In contrast with the expected results, the relationship between TTOs and academic actors does not seem to explain such differences.

Originality/value

This research contributes to the identification of the particular design characteristics that TTOs should exhibit to promote the entrepreneurial performance of universities, offering important recommendations to academic institutions regarding the efficient design of TTOs to manage university ambidexterity and to build TTOs’ entrepreneurial identity.

Details

Journal of Science and Technology Policy Management, vol. 10 no. 4
Type: Research Article
ISSN: 2053-4620

Keywords

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Book part
Publication date: 20 August 2016

Raffaella Cagliano, Christopher G. Worley and Federico F. A. Caniato

This chapter introduces the volume’s theme by describing the challenges of sustainability in the agri-food industry and the critical role of agri-food supply chains…

Abstract

Purpose

This chapter introduces the volume’s theme by describing the challenges of sustainability in the agri-food industry and the critical role of agri-food supply chains. Following a description of traditional and sustainable supply chain management practices, we discuss the likely characteristics of sustainability-oriented innovations and how organizations pursuing higher levels of economic, social, and environmental performance will need to adapt their capabilities.

Methodology/approach

Drawing on the emerging concepts and practices from sustainable supply chain management as well as traditional and emerging concepts from innovation, we develop general propositions and expectations about how organizations might address sustainable effectiveness in their supply chains. The importance of the agri-food industry to all three pillars of sustainable effectiveness and predictions about the inability to feed future populations gives the discussion a certain urgency.

Findings

Sustainability-oriented innovations in the agri-food supply chain are different from traditional innovations. We develop propositions regarding the driving motivations, their nature and scope (i.e., more radical and systemic than incremental and focused), and the importance of a multi-stakeholder approach. The 10 cases presented in the volume are summarized.

Details

Organizing Supply Chain Processes for Sustainable Innovation in the Agri-Food Industry
Type: Book
ISBN: 978-1-78635-488-4

Keywords

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