Core and critical cities of global region airport networks

Citation

Lordan, O., & Sallan, J. M. (2019). Core and critical cities of global region airport networks. Physica A: Statistical Mechanics and its Applications, 513, 724-733.
doi: https://doi.org/10.1016/j.physa.2018.08.123

Abstract

Air transport is one of the key infrastructures of today’s global economy. Connections between airports define airport networks, where nodes are cities served by airports, connected by edges if there is at least one direct flight connecting them. The aims of this research are to relate structural properties of airport networks which explain how these networks respond to isolation of critical nodes, and to gain insight into relevant socio-economic factors that influence the development of airport networks. We split the world airport network (WAN) into seven global region airport networks (GRANs), using the divisions established by OAG database. We gather information about structural properties of each GRAN determining core cities through k-core decomposition, and critical cities through robustness analysis. We find that differences of robustness across GRANs can be explained by the fraction of core cities relative to total cities. Furthermore, analysis of multilevel structure reveal relevant differences between GRANs, rooted on geographical and socio-economic factors, and give insight about how network robustness in airport networks can be enhanced.

Efficient multi-unit procurement mechanism with supply disruption risk

Citation

Xiang, J., Zhang, J., & Sallan, J. M. (2018). Efficient multi-unit procurement mechanism with supply disruption risk. Journal of Interdisciplinary Mathematics, 21(4), 883-895.
doi: 10.1080/09720502.2018.1478250

Abstract

In this paper, we study the multi-attribute multi-unit procurement mechanism design problem facing a set of potential suppliers who suffer from disruption risks. Each supplier's production cost depends on its disruption probability, and both are private information. We propose a Vickery-Clark-Groves auction with disruption risk (VCG-DR) for this problem and show that the mechanism is incentive-compatible, individual-rational and social efficient. Moreover, we compare the performance of the proposed mechanism and the popular single-attribute multi-unit forward auction (SA-MFV) with reserved attribute by numerical experiments. The results show that VCG-DR outperforms SA-MFV in both social efficiency and optimality.

Student-perceived organizational support and perceived employability in the marketing of higher education

Citation

Trullas, I., Simo, P., Fusalba, O. R., Fito, A., & Sallan, J. M. (2018). Student-perceived organizational support and perceived employability in the marketing of higher education. Journal of Marketing for Higher Education, 1–16.
UPCommons:
doi: http://doi.org/10.1080/08841241.2018.1488334

Abstract

In the current context, the need for marketing in institutions of higher education is undeniable. The specification of the student not merely as a ‘customer’ means that traditional marketing no longer has sufficient capacity to explain the behavior of the student body. In this study, a four-level relationship marketing model is tested to check the influence of perceived organizational support (POS) and perceived employability on identification with the institution and the perceived price-quality ratio and how these influence student satisfaction. In addition, the constructs prior to POS and perceived employability are identified, which are explicit enough to enable specific marketing actions to be carried out. As POS is a construct defined for the labor market, its use applied to relational marketing comes up as something innovative.

To this end, Likert scales have been designed and validated to measure these constructs. The results of this test show how the perception of organizational support depends on the relationship of the student body with the administration and management of the center. Likewise, the perception of employability depends on the perceived reputation and the perception of the promotion of employability. Furthermore, it is confirmed that satisfaction is positively related to identification and the perceived price-quality ratio, which in turn are positively related to organizational support and perceived employability.

Transformational leadership and organizational commitment: mediating role of leader-member exchange

Citation

Keskes, I., Sallan, J. M., Simo, P., & Fernandez, V. (2018). Transformational leadership and organizational commitment: mediating role of leader-member exchange. Journal of Management Development, 37(3), 271–284.
UPCommons: http://hdl.handle.net/2117/117487
doi: http://doi.org/10.1108/JMD-04-2017-0132

Abstract

Purpose
The purpose of this paper is to propose and to test three models in order to examine the mechanisms through which dimensions of transformational leadership influence different forms of organizational commitment by testing the possible mediating role of leader-member exchange (LMX) dimensions.

Design/methodology/approach
The participants in this study are represented by 427 senior executive French employees having a university degree and minimum two years of work experience in their current organization. The relationships between different variables were analyzed using structural equation modeling.

Findings
The results indicate that the dimensions of LMX mediated the relationships between the dimensions of transformational leadership and organizational commitment dimensions. The contribution dimension of LMX acts as a consequence, rather than an antecedent of commitment. These findings are important since they may serve as a bind between leadership dimensions and the kind of organizational commitment that each of these dimensions can generate in followers.

Originality/value
To the authors’ knowledge, this is the first empirical study that tests the interaction of transformational leadership and LMX on organizational commitment in a French context. The originality of this work leads on investigating these three concepts as multidimensional constructs and focusing on the mediating role of LMX in the relationship between dimensions of transformational leadership and different forms of organizational commitment which can be considered as a novelty in the field of research in this area. As a result, this study addresses concerns about that lack of academic research on the mechanisms by which transformational leaders influence the organizational commitment of their followers.

The six emotional stages of organizational change

Citation

Castillo, C., Fernandez, V., & Sallan, J. M. (2018). The six emotional stages of organizational change. Journal of Organizational Change Management, 31(3), 468–493.

doi: http://doi.org/10.1108/JOCM-05-2016-0084
UPCommons: http://hdl.handle.net/2117/118032

Abstract

Purpose
The purpose of this paper is to define a model that both describes the evolution of the emotional stages of individuals during perceived negative organizational change and explains the evolution of their behavioral patterns and the effects on relationships with social environments (family, friends, co-workers, supervisor and organization).

Design/methodology/approach
A qualitative methodological research design was adopted, using individual interviews as the primary method of qualitative data collection. In total, 15 people who experienced perceived negative organizational changes participated in this research.

Findings
Through empirical qualitative research, an adapted Kübler (1969) model was used as a starting point. Co-occurrence analysis of the interviews led to the combination of the first two stages (denial and anger) of this model because they always appeared together. Two new stages (revising and deserting), based on the research of Schalk and Roe (2007), complete the model. Subsequently, the model comprised six emotional stages: denial and anger, bargaining, depression, revising, deserting and acceptance. The results show that individuals can move freely between the first four stages, but deserting and acceptance are always the final stages. Experiencing these emotional stages can influence the relationships between individuals and their social environments. During “denial and anger” and “bargaining,” the relationships with family, friends and co-workers improve; but during depression, the relationships with family and friends deteriorate, but because co-workers become much more important, those relationships improve. Relationships with supervisors deteriorate during denial and anger and depression but remain stable during bargaining.

Research limitations/implications
Time’s passage became an inconvenience accounted for during data collection. Over time, separate events can be confused, and nuances that were once determinants can be eliminated. Longitudinal studies at various stages of the change process would complement these results.

Practical implications
These results can guide managers in foreseeing and anticipating the actions that would reduce the emotional impact of organizational change and mitigate the impact of individuals’ negative emotions on the organization.

Originality/value
This paper extends the existing theory about the strategies of coping and organizational changes.

Heuristics of node selection criteria to assess robustness of world airport network

Citation

Soria, M., Lordan, O.; Sallan, J. M. (2017). Heuristics of node selection criteria to assess robustness of world airport network. Chinese Journal of Aeronautics, 30(4), 1473-1480.
doi: http://dx.doi.org/10.1016/j.cja.2017.04.012
UPCommons: http://hdl.handle.net/2117/108021

Abstract

The world airport network (WAN) is one of the networked infrastructures that shape today's economic and social activity, so its resilience against incidents affecting the WAN is an important problem. In this paper, the robustness of air route networks is extended by defining and testing several heuristics to define selection criteria to detect the critical nodes of the WAN. In addition to heuristics based on genetic algorithms and simulated annealing, custom heuristics based on node damage and node betweenness are defined. The most effective heuristic is a multi-attack heuristic combining both custom heuristics. Results obtained are of importance not only for advance in the understanding of the structure of complex networks, but also for critical node detection.

Turnover and balance between exploration and exploitation processes for high-performance teams

Citation

Fernandez, V., Simo, P., & Sallan, J. M. (2016). Turnover and balance between exploration and exploitation processes for high-performance teams. Team Performance Management, 22(3/4), 204-222.
doi: https://doi.org/10.1108/TPM-08-2015-0035
UPCommons: http://hdl.handle.net/2117/88373

Abstract

Purpose
This paper aims to use macro-level theories based on the equilibrium between the exploration and exploitation of resources in an organisation to examine the association between turnover and performance through the analysis of a professional football (soccer) team in the Premier League, namely, Manchester United Football Club.

Design/methodology/approach
This study compiles historical data for 24 seasons of the Premier League between 1984-1985 and 2008-2009. Using these data, the authors define measures of performance and player turnover.

Findings
The results show the existence of an inverted U-shaped relationship between exploration and exploitation (turnover processes) and group efficiency under certain conditions, such as the number of work systems considered and the period during which the level of turnover is calculated.

Originality/value
Most research on employee turnover suggests that reductions in turnover have a positive effect on the efficiency of the organisation. However, the present study suggests that worker turnover can be analysed using theories based on the equilibrium between the processes of resource exploitation and exploration, especially for high-performance work groups. These theories predict an inverted U-shaped relationship between turnover and performance, which has been identified through empirical analysis.

Cascades tolerance of scale-free networks with attack cost

Citation

Chen Hong, Nai-Yu Yin, Oriol Lordan, Ning He, Jose M Sallan (2017). Cascades tolerance of scale-free networks with attack cost. International Journal of Computational Intelligence Systems,  10(1):1330-1336.

UPCommons: http://hdl.handle.net/2117/109280

Abstract

Network robustness against cascades is a major topic in the fields of complex networks. In this paper, we propose an attack-cost-based cascading failure model, where the attack cost of nodes is positively related to its degree. We compare four attacking strategies: the random removal strategy (RRS), the low-degree removal strategy (LDRS), the high-degree removal strategy (HDRS) and the genetic algorithm removal strategy (GARS). It is shown that the network robustness against cascades is heavily affected by attack costs and the network exhibits the weakest robustness under GARS. We also explore the relationship between the network robustness and tolerance parameter under these attacking strategies. The simulation results indicate that the critical value of tolerance parameter under GARS is greatly larger than that of other attacking strategies. Our work can supply insight into the robustness and vulnerability of complex networks corresponding to cascading failures.

Robustness of airline route networks

Citation

Lordan, Oriol; Sallan, Jose M; Escorihuela, Nuria; Gonzalez-Prieto, David (2015). Robustness of airline route networks, Physica A: Statistical Mechanics and its Applications, 445:18-26.

doi: http://dx.doi.org/10.1016/j.physa.2015.10.053

Abstract

Airlines shape their route network by defining their routes through supply and demand considerations, paying little attention to network performance indicators, such as network robustness. However, the collapse of an airline network can produce high financial costs for the airline and all its geographical area of influence. The aim of this study is to analyze the topology and robustness of the network route of airlines following Low Cost Carriers (LCCs) and Full Service Carriers (FSCs) business models. Results show that FSC hubs are more central than LCC bases in their route network. As a result, LCC route networks are more robust than FSC networks.

Analyzing the multilevel structure of the European airport network

Citation

Oriol Lordan, Jose M. Sallan (2017). Analyzing the multilevel structure of the European airport network. Chinese Journal of Aeronautics, 30(2):554-560.

doi: http://dx.doi.org/10.1016/j.cja.2017.01.013

Abstract

The multilayered structure of the European airport network (EAN), composed of connections and flights between European cities, is analyzed through the k-core decomposition of the connections network. This decomposition allows to identify the core, bridge and periphery layers of the EAN. The core layer includes the best-connected cities, which include important business air traffic destinations. The periphery layer includes cities with lesser connections, which serve low populated areas where air travel is an economic alternative. The remaining cities form the bridge of the EAN, including important leisure travel origins and destinations. The multilayered structure of the EAN affects network robustness, as the EAN is more robust to isolation of nodes of the core, than to the isolation of a combination of core and bridge nodes.

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.

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.

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.

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.

An Examination of the Effects of Self-Regulatory Focus on the Perception of the Media Richness: The Case of E-Mail

Citation

Armengol, Xavier; Fernandez, V.; Simo, P.; Sallan, J. M. (2015). An Examination of the Effects of Self-Regulatory Focus on the Perception of the Media Richness: The Case of E-Mail. International Journal of Business Communication
http://dx.doi.org/10.1177/2329488415572780

Abstract

Communication is a key element in organizations’ business success. The media richness theory and the channel expansion theory are two of the most influential theories regarding the selection and use of communication media in organizations; however, literature has focused little on the effects of self-regulation by managers and employees in these theories. To analyze these topics, this study develops an empirical investigation by gathering data from 600 managers and employees using a questionnaire. The results suggest that the perception of media richness is positively affected when the individual shows a promotion focus or strategy.

Análisis longitudinal de las consejerías cruzadas y su papel en la organización económica española

Citation

Poveda, G.; Sicilia, C.; Simo, P.; Sallan, J. M. (2015). Análisis longitudinal de las consejerías cruzadas y su papel en la organización económica española. Harvard-Deusto Business Research, 3(2):64-73.
http://dx.doi.org/10.3926/hdbr.7

Abstract

Interlocking directorates build relationships between corporations, and define the national economic organization. We analyze the corporate network of the IBEX 35 companies, plus two savings banks, and compare it with the same network in 2005. The most central positions in the network are occupied by large Spanish corporations, privatized in the 90s. On the other hand, in 2008 banks lose centrality, while savings bank’s centrality rises.

Robustness of airline alliance route networks

Citation

Lordan, O., Sallan, J. M., Simo, P., Gonzalez-Prieto, D. (2014). Robustness of airline alliance route networks. Communications in Nonlinear Science and Numerical Simulation, 22, 587-595.
http://dx.doi.org/10.1016/j.cnsns.2014.07.019

Abstract

The aim of this study is to analyze the robustness of the three major airline alliances’ (i.e., Star Alliance, oneworld and SkyTeam) route networks. Firstly, the normalization of a multi-scale measure of vulnerability is proposed in order to perform the analysis in networks with different sizes, i.e., number of nodes. An alternative node selection criterion is also proposed in order to study robustness and vulnerability of such complex networks, based on network efficiency. And lastly, a new procedure – the inverted adaptive strategy – is presented to sort the nodes in order to anticipate network breakdown. Finally, the robustness of the three alliance networks are analyzed with (1) a normalized multi-scale measure of vulnerability, (2) an adaptive strategy based on four different criteria and (3) an inverted adaptive strategy based on the efficiency criterion. The results show that Star Alliance has the most resilient route network, followed by SkyTeam and then oneworld. It was also shown that the inverted adaptive strategy based on the efficiency criterion – inverted efficiency – shows a great success in quickly breaking networks similar to that found with betweenness criterion but with even better results.

Robustness of the air transport network

Citation

Lordan, O.; Sallan, J. M.; Simo, P.; Gonzalez-Prieto, D. (2014). Robustness of the air transport network. Transportation research part E: Logistics and transportation review, 68:155-163
http://dx.doi.org/10.1016/j.tre.2014.05.011

Abstract

This paper presents a methodology for the detection of critical airports (those whose isolation would cause the largest losses in network connectivity) in the global air transport network (ATN), based on simulating an attack on selected ATN airports using different adaptive selection criteria. The performances of several node selection criteria are compared, together with a new criterion based on Bonacich power centrality. The results show that most critical airports can be detected with an adaptive strategy based on betweenness centrality. The detection of such airports may help the development of contingency plans to develop an appropriate response to any airport closure.

Study of the topology and robustness of airline route networks from the complex network approach: a survey and research agenda

Citation

Lordan, O., Sallan, J. M., Simo, P. (2014). Study of the topology and robustness of airline route networks from the complex network approach: a survey and research agenda. Journal of Transport Geography, 37:112-120.
http://dx.doi.org/10.1016/j.jtrangeo.2014.04.015

Abstract

Communication via air routes is an important issue in a world organized around a web city network. In this context, the robustness of network infrastructures, e.g. air transport networks, are a central issue in transport geography. Disruption of communication links by intentional causes (e.g., terrorist attack on an airport) or unintentional (e.g., weather inclemency) could be crucial for countries, regions and even the airlines affected themselves. Policymakers and the management of airlines and alliances should be able to reduce the effects of such interruptions in order to ensure good communication through air transport (i.e., maximize the robustness of their network at a reasonable cost). The literature review of the study of air transport route networks through an analysis of complex networks has highlighted a lack of contributions to the study of the topology and the robustness of such networks which contrasts, with advances undertaken for other transport networks or communication systems. This survey suggests areas in which research should be undertaken, based on the existing literature in other areas and from three different perspectives: global route networks, airline alliances, airlines and airports so as to help towards a better understanding of air traffic and, therefore, to be able to assess the potential damage of any airport being inoperative for a continent, country or airline.

Online discussion forums with embedded streamed videos on distance courses

Citation

Fernandez, V., Simo, P., Castillo, D., Sallan, J. M. (2014). Online discussion forums with embedded streamed videos on distance courses. Journal of Technology and Science Education, 4(1):25-38.
http://dx.doi.org/10.3926/jotse.91
http://www.jotse.org/index.php/jotse/article/view/91

Abstract

Existing literature on education and technology has frequently highlighted the usefulness of online discussion forums for distance courses; however, the majority of such investigations have focused their attention only on text-based forums. The objective of this paper is to determine if the embedding of streamed videos in online discussion forums generates educational dialogue and consequently the feedback that students need in a Management Accounting Course. The findings suggest some interesting issues, such as: students prefer text answers except in complex questions, and videos never replace text commentaries and explanations, but rather complement them.