miércoles, 14 de septiembre de 2016
The Platridge four thesis types
Thanks to Silvia Sunyer and Write that PhD I've just discovered the Nial McMahon article that reports the Paltridge four thesis types classification:
miércoles, 17 de agosto de 2016
Cascading failures with local load redistribution in interdependent Watts–Strogatz networks
Citation
Hong, Chen; Zhang, Jun; Du, Wen-Bo, Sallan, Jose M; Lordan, O (2016). Cascading failures with local load redistribution in interdependent Watts–Strogatz networks. International Journal of Modern Physics C. 27(11), 1650131.
doi: http://dx.doi.org/10.1142/S012918311650131X
Abstract
Cascading failures of loads in isolated networks have been studied extensively over the last decade. Since 2010, such research has extended to interdependent networks. In this paper, we study cascading failures with local load redistribution in interdependent Watts–Strogatz (WS) networks. The effects of rewiring probability and coupling strength on the resilience of interdependent WS networks have been extensively investigated. It has been found that, for small values of the tolerance parameter, interdependent networks are more vulnerable as rewiring probability increases. For larger values of the tolerance parameter, the robustness of interdependent networks firstly decreases and then increases as rewiring probability increases. Coupling strength has a different impact on robustness. For low values of coupling strength, the resilience of interdependent networks decreases with the increment of the coupling strength until it reaches a certain threshold value. For values of coupling strength above this threshold, the opposite effect is observed. Our results are helpful to understand and design resilient interdependent networks.
Hong, Chen; Zhang, Jun; Du, Wen-Bo, Sallan, Jose M; Lordan, O (2016). Cascading failures with local load redistribution in interdependent Watts–Strogatz networks. International Journal of Modern Physics C. 27(11), 1650131.
doi: http://dx.doi.org/10.1142/S012918311650131X
Abstract
Cascading failures of loads in isolated networks have been studied extensively over the last decade. Since 2010, such research has extended to interdependent networks. In this paper, we study cascading failures with local load redistribution in interdependent Watts–Strogatz (WS) networks. The effects of rewiring probability and coupling strength on the resilience of interdependent WS networks have been extensively investigated. It has been found that, for small values of the tolerance parameter, interdependent networks are more vulnerable as rewiring probability increases. For larger values of the tolerance parameter, the robustness of interdependent networks firstly decreases and then increases as rewiring probability increases. Coupling strength has a different impact on robustness. For low values of coupling strength, the resilience of interdependent networks decreases with the increment of the coupling strength until it reaches a certain threshold value. For values of coupling strength above this threshold, the opposite effect is observed. Our results are helpful to understand and design resilient interdependent networks.
sábado, 14 de mayo de 2016
Forecasting of taxi times: The case of Barcelona-El Prat airport
Citation
Lordan, Oriol; Sallan, Jose M; Valenzuela-Arroyo, Marta (2016). Forecasting of taxi times: The case of Barcelona-El Prat airport. Journal of Air Transport Management. 56(B), 118-122.
doi: http://dx.doi.org/10.1016/j.jairtraman.2016.04.015
Abstract
One of the challenges that air transport management is facing is to develop predictive tools for ground operations of aircraft, in particular of estimation of taxi times. The aim of this paper is to define a forecasting model for taxi times for a specific airport: Barcelona-El Prat. This model uses log-linear regression analysis to estimate taxi times with variables that can be computed before operation to account for route- and interaction-specific factors influencing taxi time. The resulting model has a strong predictive validity, but requires a sample size covering an extensive time of airport operations. The model results show that route-specific factors are useful to estimate taxi times, and the combination of stand and rapid exit variables (for landings) and runway (for take offs) accounts for a great part of the variability of taxi times.
Lordan, Oriol; Sallan, Jose M; Valenzuela-Arroyo, Marta (2016). Forecasting of taxi times: The case of Barcelona-El Prat airport. Journal of Air Transport Management. 56(B), 118-122.
doi: http://dx.doi.org/10.1016/j.jairtraman.2016.04.015
Abstract
One of the challenges that air transport management is facing is to develop predictive tools for ground operations of aircraft, in particular of estimation of taxi times. The aim of this paper is to define a forecasting model for taxi times for a specific airport: Barcelona-El Prat. This model uses log-linear regression analysis to estimate taxi times with variables that can be computed before operation to account for route- and interaction-specific factors influencing taxi time. The resulting model has a strong predictive validity, but requires a sample size covering an extensive time of airport operations. The model results show that route-specific factors are useful to estimate taxi times, and the combination of stand and rapid exit variables (for landings) and runway (for take offs) accounts for a great part of the variability of taxi times.
viernes, 15 de abril de 2016
Change-oriented organizational citizenship behavior: Analysis of antecedents centered on regulatory theory focus at the workplace
Citation
Simo, Pep; Sallan, Jose M; Fernandez, Vicenc; Enache, Mihaela (2016). Change-oriented organizational citizenship behavior: Analysis of antecedents centered on regulatory theory focus at the workplace. International Journal of Organizational Analysis, 24(2), 261-273.
doi: http://dx.doi.org/10.1108/IJOA-10-2014-0805
Abstract
Purpose – The aim of this research is to empirically examine the relationships between the regulatory focus in the workplace and discretionary (change-oriented OCB) and non-discretionary (intentions related to performance at work) work outcomes, in an academic work setting.
Design/methodology/approach – Data were collected using a questionnaire conducted with 251 Spanish academic workers. The data were analyzed using structural equation modeling.
Findings – Results reveal the existence of positive relationships between promotion focus and two of the outcomes: change-oriented OCB and research-oriented performance-enhancement intention. On the other hand, prevention focus had only a significant relationship with teacher-oriented performance-enhancement intention.
Research limitations/implications – The limitations of this research are twofold: on the one hand, further research should overcome the methodological limitations related with data gathering, looking for third-party measures of performance and favoring longitudinal data collection designs. On the other hand, more research is needed on the malleability of regulatory focus, defining models in which prevention and promotion focus act as mediating variables.
Practical implications – Individuals with high levels of promotion focus will put their efforts on the tasks which are more valued in the processes of tenure, promotion and compensation. On the other hand, individuals with high levels of prevention focus will tend to meet the minimum of requirements and accomplish salient job duties. These implications can be taken into account when defining human resource policies, giving a high weight in the assessment of tenure and promotion programs to those tasks on which the organization wants their promotion focus individuals to center their attention.
Originality/value – This paper is one of the first efforts of validating the regulatory focus of work scale in organizational and academic contexts different from the initial validation study. The study also contributes to research on the antecedents of change-oriented organizational citizenship behaviors, and defines new measures of intentions to perform in specific working activities.
Simo, Pep; Sallan, Jose M; Fernandez, Vicenc; Enache, Mihaela (2016). Change-oriented organizational citizenship behavior: Analysis of antecedents centered on regulatory theory focus at the workplace. International Journal of Organizational Analysis, 24(2), 261-273.
doi: http://dx.doi.org/10.1108/IJOA-10-2014-0805
Abstract
Purpose – The aim of this research is to empirically examine the relationships between the regulatory focus in the workplace and discretionary (change-oriented OCB) and non-discretionary (intentions related to performance at work) work outcomes, in an academic work setting.
Design/methodology/approach – Data were collected using a questionnaire conducted with 251 Spanish academic workers. The data were analyzed using structural equation modeling.
Findings – Results reveal the existence of positive relationships between promotion focus and two of the outcomes: change-oriented OCB and research-oriented performance-enhancement intention. On the other hand, prevention focus had only a significant relationship with teacher-oriented performance-enhancement intention.
Research limitations/implications – The limitations of this research are twofold: on the one hand, further research should overcome the methodological limitations related with data gathering, looking for third-party measures of performance and favoring longitudinal data collection designs. On the other hand, more research is needed on the malleability of regulatory focus, defining models in which prevention and promotion focus act as mediating variables.
Practical implications – Individuals with high levels of promotion focus will put their efforts on the tasks which are more valued in the processes of tenure, promotion and compensation. On the other hand, individuals with high levels of prevention focus will tend to meet the minimum of requirements and accomplish salient job duties. These implications can be taken into account when defining human resource policies, giving a high weight in the assessment of tenure and promotion programs to those tasks on which the organization wants their promotion focus individuals to center their attention.
Originality/value – This paper is one of the first efforts of validating the regulatory focus of work scale in organizational and academic contexts different from the initial validation study. The study also contributes to research on the antecedents of change-oriented organizational citizenship behaviors, and defines new measures of intentions to perform in specific working activities.
sábado, 12 de marzo de 2016
Algoritmos genéticos
Esta cita de Darwin resume en una frase el funcionamiento de los algoritmos genéticos.
domingo, 27 de diciembre de 2015
Probabilidad de empate
En relación al empate que hoy se ha producido en la asamblea de la CUP, lamentamos tener que desmentir afirmaciones como esta:
La probabilidad de que se haya producido este empate no es tan baja como indica Mario Bilbao. La probabilidad de que determinado número de asistentes a la asamblea vote por la investidura de Mas es función de la probabilidad p de que cada uno de los miembros de la asamblea desee investir presidente a Mas: los resultados habrían sido muy distintos si todos los asistentes estuvieran convencidos de investir a Mas (p próxima a 1) o de no investirlo (p próxima a 0). Para determinar la probabilidad de que exactamente 1515 de los 3030 asistentes hayan votado por la investidura de Mas, hemos de utilizar la distribución de probabilidad binomial.
El siguiente gráfico muestra la probabilidad de que se produzca empate (prob) en función de la probabilidad de que un miembro de la asamblea desee que Mas sea investido (p):
Como Antoni Ítalo (entre otros) ha indicado, la probabilidad de empate es como máximo del 1,45%, y es (ahora sí) prácticamente despreciable si p no está entre 0,47 y 0,52 aproximadamente.
La probabilidad de que se haya producido este empate no es tan baja como indica Mario Bilbao. La probabilidad de que determinado número de asistentes a la asamblea vote por la investidura de Mas es función de la probabilidad p de que cada uno de los miembros de la asamblea desee investir presidente a Mas: los resultados habrían sido muy distintos si todos los asistentes estuvieran convencidos de investir a Mas (p próxima a 1) o de no investirlo (p próxima a 0). Para determinar la probabilidad de que exactamente 1515 de los 3030 asistentes hayan votado por la investidura de Mas, hemos de utilizar la distribución de probabilidad binomial.
El siguiente gráfico muestra la probabilidad de que se produzca empate (prob) en función de la probabilidad de que un miembro de la asamblea desee que Mas sea investido (p):
Como Antoni Ítalo (entre otros) ha indicado, la probabilidad de empate es como máximo del 1,45%, y es (ahora sí) prácticamente despreciable si p no está entre 0,47 y 0,52 aproximadamente.
lunes, 16 de noviembre de 2015
The Spanish corporate structure through interlocking directorates
Citation
Sicilia, Carlos; Sallan, Jose M.; Simo, Pep (2016). The Spanish corporate structure through interlocking directorates. Cuadernos de Gestión, 63(1):63-84.
DOI: http://dx.doi.org/10.5295/cdg.120336ps
Abstract
The objective of this paper is to determine to what extent globalisation pressures are changing networks modelled on continental capitalism into Anglo-Saxon models. For this purpose we analyse the Spanish network of interlocks, comparing the present structure with that of 1993. We show how, although Spanish corporative structure continues to display characteristics of the continental economies, some major banks are significantly reducing industrial activity. Nevertheless, the financial organisations continue to maintain a close relationship with sectors such as construction and services. According to the theories on the role of the interlocking directorates, the companies in these sectors assure their access to banking credit by incorporating advisors from financial organisations to their board of directors.
El objetivo de este trabajo es determinar en qué medida las presiones de la globalización han cambiado los modelos que siguen las redes corporativas españolas desde los propios del capitalismo continental hacia los modelos anglosajones. Para ello se analiza la red española de consejerías cruzadas, comparando la estructura actual con la de 1993. Se muestra cómo, a pesar de la estructura corporativa española continúa mostrando características de las economías continentales, algunos de los principales bancos están reduciendo significativamente la actividad industrial. No obstante, las entidades financieras siguen manteniendo una estrecha relación con sectores como la construcción y los servicios. De acuerdo con las teorías sobre el papel de las consejerías cruzadas, las empresas de estos sectores tratan de asegurar su acceso al crédito bancario mediante la incorporación de asesores de las entidades financieras a su consejo de administración.
Sicilia, Carlos; Sallan, Jose M.; Simo, Pep (2016). The Spanish corporate structure through interlocking directorates. Cuadernos de Gestión, 63(1):63-84.
DOI: http://dx.doi.org/10.5295/cdg.120336ps
Abstract
The objective of this paper is to determine to what extent globalisation pressures are changing networks modelled on continental capitalism into Anglo-Saxon models. For this purpose we analyse the Spanish network of interlocks, comparing the present structure with that of 1993. We show how, although Spanish corporative structure continues to display characteristics of the continental economies, some major banks are significantly reducing industrial activity. Nevertheless, the financial organisations continue to maintain a close relationship with sectors such as construction and services. According to the theories on the role of the interlocking directorates, the companies in these sectors assure their access to banking credit by incorporating advisors from financial organisations to their board of directors.
El objetivo de este trabajo es determinar en qué medida las presiones de la globalización han cambiado los modelos que siguen las redes corporativas españolas desde los propios del capitalismo continental hacia los modelos anglosajones. Para ello se analiza la red española de consejerías cruzadas, comparando la estructura actual con la de 1993. Se muestra cómo, a pesar de la estructura corporativa española continúa mostrando características de las economías continentales, algunos de los principales bancos están reduciendo significativamente la actividad industrial. No obstante, las entidades financieras siguen manteniendo una estrecha relación con sectores como la construcción y los servicios. De acuerdo con las teorías sobre el papel de las consejerías cruzadas, las empresas de estos sectores tratan de asegurar su acceso al crédito bancario mediante la incorporación de asesores de las entidades financieras a su consejo de administración.
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