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1 – 10 of 39
Article
Publication date: 27 April 2020

J. Guillermo Lopez-Lara, Mauro Eduardo Maya, Alejandro González, Antonio Cardenas and Liliana Felix

The purpose of this paper is to present a new vision-based control method, which enables delta-type parallel robots to track and manipulate objects moving in arbitrary…

Abstract

Purpose

The purpose of this paper is to present a new vision-based control method, which enables delta-type parallel robots to track and manipulate objects moving in arbitrary trajectories. This constitutes an enhanced variant of the linear camera model-camera space manipulation (LCM-CSM).

Design/methodology/approach

After obtaining the LCM-CSM view parameters, a moving target’s position and its velocity are estimated in camera space using Kalman filter. The robot is then commanded to reach the target. The proposed control strategy has been experimentally validated using a PARALLIX LKF-2040, an academic delta-type parallel platform and seven different target trajectories for which the positioning errors were recorded.

Findings

For objects that moved manually along a sawtooth, zigzag or increasing spiral trajectory with changing velocities, a maximum positioning error of 4.31 mm was found, whereas objects that moved on a conveyor belt at constant velocity ranging from 7 to 12 cm/s, average errors between 2.2-2.75 mm were obtained. For static objects, an average error of 1.48 mm was found. Without vision-based control, the experimental platform used has a static positioning accuracy of 3.17 mm.

Practical implications

The LCM-CSM method has a low computational cost and does not require calibration or computation of Jacobians. The new variant of LCM-CSM takes advantage of aforementioned characteristics and applies them to vision-based control of parallel robots interacting with moving objects.

Originality/value

A new variant of the LCM-CSM method, traditionally used only for static positioning of a robot’s end-effector, was applied to parallel robots enabling the manipulation of objects moving along unknown trajectories.

Details

Industrial Robot: the international journal of robotics research and application, vol. 47 no. 4
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 July 1996

David Spener

As has been widely recognized in the literature, the post‐war economic boom which drew to a close by the early 1970s has been followed by an intense period of industrial…

Abstract

As has been widely recognized in the literature, the post‐war economic boom which drew to a close by the early 1970s has been followed by an intense period of industrial restructuring characterized by marked instability in all three major spheres of economic activity: production, distribution, and finance. This process has taken place both at the global level and at the level of national economies (Cardenas, 1990). It reflects a profound change in the mode of capitalist accumulation. Prior to the current round of restructuring, accumulation was taken to be principally the inward‐oriented task of each nation's own economy. Now, it seems that successful capital accumulation (i.e. development) depends most upon a nation's competitive integration into the world market for goods and services (Garrido, 1995). The present mode of accumulation implies an opening of national economies to international trade in commodities and capital, both among the advanced industrial nations and between the industrialized and the newly‐industrializing countries. This has generated a heightened degree of competition among countries and among firms, given that the easy movement of capital, goods, and services has allowed for real competition to emerge among dispersed places around the globe based upon their comparative financial and productive advantages.

Details

International Journal of Sociology and Social Policy, vol. 16 no. 7/8
Type: Research Article
ISSN: 0144-333X

Article
Publication date: 1 August 2016

Cory Hallam, Gianluca Zanella, Carlos Alberto Dorantes Dosamantes and Cesar Cardenas

The purpose of this paper is to investigate the influence of temporal construal theory on entrepreneurial intention models using a three-country study. Inclusion of temporal…

1452

Abstract

Purpose

The purpose of this paper is to investigate the influence of temporal construal theory on entrepreneurial intention models using a three-country study. Inclusion of temporal construal theory in intent models would suggest path dependent influence on intent, and more specifically, that intent may be subdivided into temporally based categories, broadly codified as short-term and long-term intent.

Design/methodology/approach

A quasi-experimental study of 1,046 university students in business and engineering from the USA, Mexico, and Spain was conducted. A temporal construal model of intent is proposed, including measures of short-term and long-term intent. Entrepreneurial self-efficacy (ESE), part of the perceived behavioral control in the theory of planned behavior, is utilized to structure the model antecedents.

Findings

The results suggest the existence of differences in individual entrepreneurial intent measures depending on the individual’s perception of when the entrepreneurial event is anticipated to occur in their lives. Utilizing an ESE construct, the authors demonstrated that short-term entrepreneurial intent significantly mediates the effect of ESE on long-term entrepreneurial intent. Furthermore, the results identify a mediating model that does not depend on regional country differences, thus supporting the generalizability of the findings.

Originality/value

The paper bridges temporal construal theory and entrepreneurial intentions to qualify the path dependent effects of this psychological phenomena and its impact on identifying nascent entrepreneurs. The multi-country results indicate the ability to generalize the findings into a more complete theoretical model of entrepreneurial intention and suggests potential improvements in predictive models that currently use single or averaged measures of entrepreneurial intent.

Details

International Journal of Entrepreneurial Behavior & Research, vol. 22 no. 5
Type: Research Article
ISSN: 1355-2554

Keywords

Article
Publication date: 8 January 2019

Luis Ricardo Jacobo, Rafael Garcia, Victor Hugo Lopez and Antonio Contreras

The purpose of this paper is to study the effect of heat treatment (HT) applied to an API X60 steel in corrosion resistance and stress corrosion cracking (SCC) susceptibility…

Abstract

Purpose

The purpose of this paper is to study the effect of heat treatment (HT) applied to an API X60 steel in corrosion resistance and stress corrosion cracking (SCC) susceptibility through slow strain rate tests (SSRT) in NS4 solution and congenital water (CW) to assess external and internal SCC, respectively.

Design/methodology/approach

API X60 steel was heat treated at a temperature of 1,200°C for 30 min followed by water quenching. Specimens from this steel were machined according to NACE TM 198. SSRT were performed in a constant extension rate tests (CERT) machine at room temperature at a strain rate of 1 × 10–6 s–1. For this purpose, a glass cell was used. Corrosion behavior was evaluated through polarization curves (PCs).

Findings

The SCC index obtained from SSRT indicates that the steel heat treated could be susceptible to SCC in CW and NS4 solution; the mechanism of SCC was hydrogen embrittlement. Thus, CW may promote the SCC phenomenon in pipelines. HT improves the steel corrosion resistance. Higher corrosion rate (CR) was observed when the steel is exposed to CW. The corrosion process in X60 steel shows that the oxidation reaction in the anodic branch corresponds to an activation process, and the cathode branches reveal a diffusion process.

Originality/value

The purpose of the heat treatment applied to X60 steel was to generate a microstructure of acicular ferrite to improve the corrosion resistance and SCC behavior.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Open Access
Article
Publication date: 19 August 2021

Antonios Marios Koumpias, Jorge Martínez-Vázquez and Eduardo Sanz-Arcega

The purpose of this paper is to quantify to what extent the housing bubble in the early-to-mid 2000s in Spain exacerbated land planning corruption among Spain’s largest…

1564

Abstract

Purpose

The purpose of this paper is to quantify to what extent the housing bubble in the early-to-mid 2000s in Spain exacerbated land planning corruption among Spain’s largest municipalities.

Design/methodology/approach

The authors exploit plausibly exogenous variation in housing prices induced by changes in local mortgage market conditions; namely, the rapid expansion of savings banks (Cajas de Ahorros). Accounting for electoral competition in the 2003–2007 and 2007–2009 electoral cycles among Spanish municipalities larger than 25,000 inhabitants, the authors estimate a positive relationship between housing prices and land planning corruption in municipalities with variation in savings bank establishments using instrumental variables techniques.

Findings

A 1% increase in housing prices leads to a 3.9% points increase in the probability of land planning corruption. Moreover, absolute majority governments (not needing other parties’ support) are more susceptible to the incidence of corruption than non-majority ones. Two policy implications to address corruption emerge: enhance electoral competition and increase scrutiny over land planning decisions in sparsely populated.

Originality/value

First empirical evidence of a formal link between the 2000s housing bubble in Spain and land planning corruption.

Details

Applied Economic Analysis, vol. 30 no. 89
Type: Research Article
ISSN:

Keywords

Article
Publication date: 2 November 2015

Ana Rocío Cárdenas Maita, Lucas Corrêa Martins, Carlos Ramón López Paz, Sarajane Marques Peres and Marcelo Fantinato

Process mining is a research area used to discover, monitor and improve real business processes by extracting knowledge from event logs available in process-aware information…

4033

Abstract

Purpose

Process mining is a research area used to discover, monitor and improve real business processes by extracting knowledge from event logs available in process-aware information systems. The purpose of this paper is to evaluate the application of artificial neural networks (ANNs) and support vector machines (SVMs) in data mining tasks in the process mining context. The goal was to understand how these computational intelligence techniques are currently being applied in process mining.

Design/methodology/approach

The authors conducted a systematic literature review with three research questions formulated to evaluate the use of ANNs and SVMs in process mining.

Findings

The authors identified 11 papers as primary studies according to the criteria established in the review protocol. Most of them deal with process mining enhancement, mainly using ANNs. Regarding the data mining task, the authors identified three types of tasks used: categorical prediction (or classification); numeric prediction, considering the “regression” type, and clustering analysis.

Originality/value

Although there is scientific interest in process mining, little attention has been specifically given to ANNs and SVM. This scenario does not reflect the general context of data mining, where these two techniques are widely used. This low use may be possibly due to a relative lack of knowledge about their potential for this type of problem, which the authors seek to reverse with the completion of this study.

Details

Business Process Management Journal, vol. 21 no. 6
Type: Research Article
ISSN: 1463-7154

Keywords

Abstract

Details

Academia Revista Latinoamericana de Administración, vol. 32 no. 4
Type: Research Article
ISSN: 1012-8255

Article
Publication date: 24 March 2021

Rodrigo Martins, Francisco Fernandes, Virginia Infante and Antonio R. Andrade

The purpose of this paper is to describe an integer linear programming model to schedule the maintenance crew and the maintenance tasks in a bus operating company.

Abstract

Purpose

The purpose of this paper is to describe an integer linear programming model to schedule the maintenance crew and the maintenance tasks in a bus operating company.

Design/methodology/approach

The proposed methodology relies on an integer linear programming model that finds feasible maintenance schedules. It minimizes the costs associated with maintenance crew and the costs associated with unavailability. The model is applied in a real-world case study of a Portuguese bus operating company. A constructive heuristic approach is put forward, based on solving the maintenance scheduling problem for each bus separately.

Findings

The heuristic finds better solutions than the exact methods (based on branch-and-bound techniques) in a much lower computational time.

Practical implications

The results suggest the relevance of such heuristic approaches for maintenance scheduling in practice.

Originality/value

This proposed model is an effective decision-making support method that provides feasible maintenance schedules for the maintenance technicians and for the maintenance tasks in a fleet of buses. It also complies with several operational, technical and labour constraints.

Details

Journal of Quality in Maintenance Engineering, vol. 28 no. 2
Type: Research Article
ISSN: 1355-2511

Keywords

Article
Publication date: 23 August 2013

Ana María Lucia‐Casademunt, J. Antonio Ariza‐Montes and Alfonso Carlos Morales‐Gutiérrez†

Employee well‐being (WB) is a strategic reference of prime importance due to its impact on human capital, employee health and quality in working life, factors that are key to…

1130

Abstract

Purpose

Employee well‐being (WB) is a strategic reference of prime importance due to its impact on human capital, employee health and quality in working life, factors that are key to achieving successful organisations. The purpose of the current study is to assess the WB of female managers in the European workplace. The research analyses three dimensions (job satisfaction, comfort and enthusiasm) and the effect of job‐related factors on each one of these.

Design/methodology/approach

The Mental Health and Vitamin models (Warr, 1987) were taken as the starting‐point of the research. An alternative econometric method – an artificial neural network known as extreme learning machine was applied to a sample of 99 female managers collected from the 5th European Working Conditions Survey‐2010

Findings

The results obtained confirm that this methodology is valid to efficiently classify European female managers into those who feel satisfied with their jobs, calm and relaxed, and cheerful and in good spirits, and those who do not. Furthermore, the resulting model identifies the strongest factors important in determining the varied dimensions of occupational WB achieved.

Originality/value

Even today, despite the important contribution women managers make to the management of organisations, they have to face many challenges and overcome serious barriers in achieving and staying in positions of leaderships when compared to their male counterparts.

Propósito

El bienestar laboral constituye un referente estratégico de primer orden por su impacto sobre el capital humano – salud y calidad de vida laboral de los empleados –, en aras de alcanzar organizaciones exitosas. El objetivo del presente artículo es analizar el bienestar laboral a partir de sus tres dimensiones (satisfacción, confort y entusiasmo) de las mujeres que ocupan puestos de dirección en Europa y el efecto de ciertos factores laborales.

Diseño/metodología/enfoque

Se adopta como punto de partida los modelos teóricos de salud mental y vitamínico (Warr, 1987), aplicando un método econométrico novedoso – redes neuronales artificiales –, a una muestra de 99 mujeres directivas extraída de la V Encuesta Europea de Condiciones de Trabajo (2010).

Resultados

Los resultados obtenidos confirman la validez de esta novedosa metodología para clasificar eficazmente a las mujeres directivas que presentan un elevado grado de bienestar laboral. Por otra parte, con el modelo resultante se identifican los factores más determinantes para el logro de cada una de las dimensiones que constituyen el bienestar laboral.

Originalidad

Las mujeres directivas, quienes a pesar de lo mucho que tienen que aportar en la gestión de las organizaciones, aún hoy encuentran que su acceso y permanencia en los puestos de dirección está colmado de desafíos y barreras difíciles de superar en comparación con sus homólogos masculinos.

Open Access
Article
Publication date: 7 March 2019

Antonio-Miguel Nogués-Pedregal

This paper aims to show that tourism is one of the most perfect creations of the capitalist mode of production insofar as not only does it consume places and territories and…

1456

Abstract

Purpose

This paper aims to show that tourism is one of the most perfect creations of the capitalist mode of production insofar as not only does it consume places and territories and perpetuate dependency relations, but in the expressive dimension, it also produces feelings and meanings and generates a new relationship of the past with the present and future (chronotope).

Design/methodology/approach

The study was carried out using a socio-anthropological approach with participant observation over several decades.

Findings

The modes of time are described and how the tourism chronotope shapes the historic centre of a consolidated tourist destination. The case study, analysed with the model of the “conversion of place through the mediation of tourism space”, illustrates the prevalence of instrumental and commercial values over one’s own aesthetic-expressive values in tourism contexts. This fact encourages the emergence of local political projects and the incorporation of uniformities outside the local place. These processes end up uprooting the anchors from collective memory. The definition of territories according to visitors’ imaginaries and expectations encourages the abusive occupation of public space and the adoption of new aesthetic attributes of urban space.

Research limitations/implications

Because of the chosen research approach and methodologies, the research results may lack generalisability. Therefore, researchers are encouraged to test both the model and the propositions further.

Originality/value

This study approaches the relationship of the idea Tourism with the idea Development based on the anchors of memory.

Details

Journal of Tourism Analysis: Revista de Análisis Turístico, vol. 26 no. 1
Type: Research Article
ISSN: 2254-0644

Keywords

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