Search results

The purpose of this paper is to analyse and describe several trust and reputation models for distributed and heterogeneous networks and compare some of them in order to provide an evaluation amongst some of the most relevant works in this field.

The authors have developed a trust and reputation models simulator for wireless sensor networks, called TRMSim‐WSN, and implemented several trust models for distributed networks in order to test their accuracy as well as their resilience against a set of specific security threats that can be applied in these particular systems, as the paper will show.

The analysis of the outcomes obtained from the experiments revealed that while some models have a reasonably good performance against certain security threats, none of them behaves as would be desired under any circumstances.

Ongoing work is focused on the implementation of several trust and reputation models in the simulator TRMSim‐WSN, in order to have a wider range of possibilities for comparison. Furthermore, the authors are planning to include additional security threats that allow the testing of those models under new undesirable situations.

The experiments show that when deciding which trust and/or reputation model is more suitable or adequate to be applied, it is crucial to study and analyse the specific features of the distributed network where such model is to be deployed, as well as the possible security threats that can spoil its accuracy.

As far as is known, this is one of the few works in the field of trust and reputation in distributed systems where no new model is presented, but a comparison and analysis of some of the current most representative ones is carried out.

The purpose of the paper is to provide a two‐tier framework for managing semantic‐aware distributed firewall policies to be applied to the devices existing in one administrative domain.

Special attention is paid to the CIM‐based information model defined as the ontology to be used in this framework and the AI‐based reasoning mechanisms and components used to perform the conflict discovery tasks over the distributed firewall policies.

Mechanisms presented allow the solving some of the current issues of the network‐centric security model being used in the Internet. The two‐tier framework designed provides semantic‐aware mechanisms to perform conflict detection and automatic enforcement of policy rules in the distributed firewall scenario. This framework is based on the use of a standard information model and a semantic‐aware policy language to formally define (and then process) firewall policies.

Ongoing work is focused on identifying all kind of conflicts and anomalies that may exist in firewall systems; in parallel to this task a semi‐automatic resolver of conflicting policies is currently under design.

Network and security administrators can specify firewall policies and validate them to find syntactic and semantic errors (i.e. policy conflicts). A framework for automated validation and distribution of policies at different levels is included. This ensures that firewall policies produce the desired effects, facilitating the creation and maintenance of firewall rules in one administrative domain.

A practical and novel two‐tier system that provides detection of conflicts in rules existing in a distributed firewall scenario and the automatic and secure deployment of these rules. A packet‐filtering model, which is simple and powerful enough for the conflict discovery and rule analysis processes, has been proposed. Moreover, ontology and rule reasoning are being proposed as techniques for the conflict detection problem in this particular scenario.

Based on the resource orchestration perspective, this paper aims to examine whether family firms are more efficient in their collaboration for innovation process than non-family firms, considering different types of collaboration for innovation depending on the kind of partner.

This study empirically develops and tests the hypotheses based on a panel data sample of 14,937 firm-year observations from 1,867 Spanish manufacturing firms over the period 2007–2014, performing a Propensity Score Matching (Propensity score matching)-based analysis.

Results reveal that family firms outperform non-family firms, despite less collaboration and innovation inputs, thereby extending the ongoing debate surrounding the innovation efficiency of family firms. Family firms obtained better results through vertical collaborations for innovation, both in terms of product and process innovations. For horizontal collaborations, family firms only outperform their non-family counterparts in process innovation. When collaborating with universities and other research centers, there are no significant differences in the innovation outcomes between the two groups.

Recent literature points out that more research is needed to know when, how and under what circumstances family firms show superior innovative efficiency. This work empirically proves that family firms outperform non-family firms in collaboration for innovation. However, not all collaboration partners help family firms to reach this superior innovative efficiency. Family firms obtained better results just through vertical and horizontal collaborations.

We conjecture that there are five stages to academic entrepreneurship: motivation, governance, selection, competition, and performance. The process of academic entrepreneurship originates with the motivation of faculty, universities, industry, and government to commercialize knowledge that originates within the university setting. The model conceptualizes that the governance and competitiveness of the commercialized knowledge moderate the mode selection and ultimately the performance of academic entrepreneurship. The conceptual and empirical support for the model are derived from a theory-driven synthesis of articles related to academic entrepreneurship.

The purpose of this paper is to study the internationalization of family firms, exploring specifically if the transition from family control to non-family control (losing family managerial influence) affects a firm’s export activity.

Based on panel data for Spanish firms from 2006 to 2012, a random effect tobit and probit regression and a propensity score matching were run on a sample of 225 firms moving from family to non-family control (switchers) matched with 4,213 firms remaining under family control (non-switchers).

Although from a static viewpoint family controlled firms export less than their non-family counterparts, from a dynamic perspective family firms remaining under family control (non-switchers) are associated with a fall in export activity in comparison with family firms transitioning to non-family control (switchers). Both findings are related back to the socioemotional wealth (SEW) perspective.

The findings of this study shed light on the trade-offs that family firms experience in order to balance their desire to increase their internationalization (and the risk associated with it) and their wish to maintain SEW.

The findings should encourage family owners and managers to take long-term strategic decisions leading to internationalization which, although risky, will prevent subsequent loss of SEW in terms of family control.

This work provides evidence concerning family firms’ willingness to undertake risky activities, such as internationalization, considering the threats to their wealth.

The purpose of this paper is to investigate contingency factors on the emergence of university spin-off firms. The institutional and organisational factors the paper explores comprise the transfer potential of the university, the strategy and characteristics of the University Technology Transfer Organisations and specific support for spin-off formation.

Based on a unique data set, this cross-sectional study analyses the population of 54 higher education institutions in Germany. At this, 31.4 per cent of the German universities with technology transfer activities participated in this study.

The research identifies a high degree of heterogeneity in the qualification of University Technology Transfer Offices (UTTO) staff and the existence of an entrepreneurship support programme as important antecedents of spin-off formation. In addition, the results reveal that pursuing different or multiple transfer strategies will not be detrimental to the establishment of spin-offs.

It seems that there is still a lack of consensus with respect to the importance of spin-offs as an effective channel to transform research results into economic value. Furthermore, universities aiming at the promotion of spin-offs need appropriate regulations which do not jeopardise the usage of research outcomes for entrepreneurial purposes.

This study contributes to enhance the knowledge on what promotes and inhibits the formation of university spin-off firms, as it first analyses a considerable population of UTTOs in Germany and explicitly considers underexplored and new contingency factors.

Drawing on the Theory of Planned Behaviour (TBP) and Social Cognitive Theory (SCT), this study delves into how, in entrepreneurship-unfriendly environments, university students’ entrepreneurial intention (EI) is shaped, focusing particularly on the role of entrepreneurship education (EE) and an entrepreneurial family context (EFC).

A sample of 688 students at a Spanish university was used for testing our hypotheses using GUESSS project data, through PLS-SEM regression and multigroup analysis (entrepreneurship course vs non-course students).

Positive and significant impacts of entrepreneurial attitude (EA) and entrepreneurial self-efficacy (ESE) on EI, and of subjective norms (SN) on EA and ESE, were found in both groups. Conversely, the impacts of an EFC on EA, SN and EI were significant only for course students, and the impact of SN on EI was significant only for non-course students. The impact of EFC on ESE was not significant for either group.

This investigation delves into how the TPB components shape university students’ EI in entrepreneurship-unfriendly contexts, and offers an original multigroup analysis to explore the role of EE in such dynamics. A novel contribution of this study is the finding that EE is a relevant catalyser for making entrepreneurial parents become an effective trigger for entrepreneurship. Conversely, EE was, unexpectedly, deemed irrelevant or counter-productive for some aspects of entrepreneurial dynamics. Further research is encouraged, delving into the role of social and cultural contexts.

The paper's purpose is twofold: to provide a predictive model for estimating in‐hospital mortality rates after coronary artery bypass grafting (CABG) in Spanish autonomous regions (AR) after adjusting relevant factors; and to determine whether there is a difference between expected and observed mortality rates.

All patients registered in a minimum basic data set (MSBD) undergoing CABG between 2000 and 2004 were selected. After bivariate analysis to explore associations between in‐hospital death and other variables, a multivariate analysis using logistic regression was conducted. The predictive model was evaluated using calibration and discrimination techniques. Standardized mortality ratios by AR were calculated.

The expected Spanish in‐hospital mortality rate after CABG was 7.68 and the observed rate was 7.69 deaths per 100 operations. Discrimination obtained with the model resulted in an area under the curve of 0.70 (95 per cent CI, 0.69‐0.71). When each AR's mortality rate is calculated and compared with the observed rate, some ARs present an observed mortality rate higher or lower than the expected rate according to adjusted variables in the model.

The MSBD registry does not contain patients' critical data, such as arterial damage severity, or in which hospital procedures were performed.

There are factors related to individual patient variation, financial resources or healthcare quality in different ARs, which should be investigated in follow‐up studies.

The paper shows that, although the global expected mortality rate is almost the same as the observed Spanish mortality rate, this similarity disappears when AR rates are compared.

Healthcare risk epidemiology identifies medication error as the commonest cause of adverse effects on patients. Medication error can occur at any phase of the complex medication process so prevalence rates need to be estimated at each drug treatment phase: prescription, transcription and administration along with their clinical repercussions. This paper aims to investigate this issue.

Medication errors were recorded on an ad hoc sheet and staff were observed handling medications. Recorded errors were later classified and their clinical repercussions determined by experts.

In total 757 inpatients and 5,466 drug prescriptions were studied. The prescription error rate was 4.79 percent (95 percent CI 4.21‐5.36). The most frequent error in this phase was failing to observe international prescribing standards. The highest error rate was found in transcription (14.61 percent, 95 percent CI 13.67‐15.54). Almost 1,900 dose administrations were observed. There was a 9.32 percent error rate (95 percent CI 7.98‐10.67). The commonest error in this phase was omission. Most were transcription errors, which were detected before harm was done.

The dispensation phase is absent.

Errors can be reduced if they are understood. Education and training based on the study's findings can reduce medication errors.

The paper highlights ways to reduce errors in the medication process.