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Article
Publication date: 20 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

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Book part
Publication date: 3 September 2019

Lorenzo Fusaro

Commenting on the Mexican Revolution in 1938, Trotsky argued that the country might achieve “national independence,” understood as a break with dependency relations…

Abstract

Commenting on the Mexican Revolution in 1938, Trotsky argued that the country might achieve “national independence,” understood as a break with dependency relations. Whether this might occur depended – Trotsky continued – on “international factors.” Though not engaging with Mexico, Antonio Gramsci made a similar theoretical point. It is hence from this perspective that this chapter analyses the Mexican Revolution, asking whether it led to a break in dependency relations and the attainment of “national independence” or what I refer to as “relative geopolitical autonomy.” Presenting a framework of analysis largely based on the work of Gramsci that highlights its continuity with the thought of Marx, the chapter will answer negatively to this question. The chapter starts from the idea that Porfirio Díaz’s regime was unable to adapt the economic structure (still pre-capitalist) to the complex superstructures (capitalist), that is, to realize an historic bloc. It would be this job that the emergent Mexican bourgeoisie sought to finish. However, the situation is complicated by the powerful emergence of social movements from below, constituted largely by landless peasants, and to a lesser extent, the industrial proletariat. I will therefore argue that the revolution has been both “passive” and “bounded.” The term passive revolution will be applied to the last phase of the revolution as the emerging bourgeoisie successfully coopted the demands of the popular masses thereby “passivizing” them. But crucially, the revolution was also “bounded” because international factors, and especially US influence, played a conditioning role throughout the revolutionary process. At the same time, it would be the very “passive” nature of the revolution that would contribute to the reproduction of relations of dependency. Hence the chapter concludes that the period Trotsky commented upon (the Cárdenas period) is the highest level of “independence” Mexico achieved, only to decrease again over the years.

Details

Class History and Class Practices in the Periphery of Capitalism
Type: Book
ISBN: 978-1-78973-592-5

Keywords

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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

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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…

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

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Article
Publication date: 7 May 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…

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

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Book part
Publication date: 27 September 2019

Abstract

Details

Innovation and Entrepreneurship: A New Mindset for Emerging Markets
Type: Book
ISBN: 978-1-78973-701-1

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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…

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

Best Practices in Green Supply Chain Management
Type: Book
ISBN: 978-1-78756-216-5

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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

Abstract

Details

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

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