Fast Authentication in Heterogeneous Wireless Networks

The growing diffusion of wireless devices is leading to an increasing demand for mobility and security. At the same time, most applications can only tolerate short breaks in the data flow, so that it is a challenge to find out mobility and authentication methods able to cope with these constraints. This paper aims to propose an authentication scheme which significantly shortens the authentication latency and that can be deployed in a variety of wireless environments ranging from common Wireless LANs (WLANs) to satellite-based access networks

Identifying influencers in a social network : the value of real referral data

Individuals influence each other through social interactions and marketers aim to leverage this interpersonal influence to attract new customers. It still remains a challenge to identify those customers in a social network that have the most influence on their social connections. A common approach to the influence maximization problem is to simulate influence cascades through the network based on the existence of links in the network using diffusion models. Our study contributes to the literature by evaluating these principles using real-life referral behaviour data. A new ranking metric, called Referral Rank, is introduced that builds on the game theoretic concept of the Shapley value for assigning each individual in the network a value that reflects the likelihood of referring new customers. We also explore whether these methods can be further improved by looking beyond the one-hop neighbourhood of the influencers. Experiments on a large telecommunication data set and referral data set demonstrate that using traditional simulation based methods to identify influencers in a social network can lead to suboptimal decisions as the results overestimate actual referral cascades. We also find that looking at the influence of the two-hop neighbours of the customers improves the influence spread and product adoption. Our findings suggest that companies can take two actions to improve their decision support system for identifying influential customers: (1) improve the data by incorporating data that reflects the actual referral behaviour of the customers or (2) extend the method by looking at the influence of the connections in the two-hop neighbourhood of the customers

Cognitive Radio Networks: Realistic or Not?

A large volume of research has been conducted in the cognitive radio (CR) area the last decade. However, the deployment of a commercial CR network is yet to emerge. A large portion of the existing literature does not build on real world scenarios, hence, neglecting various important interactions of the research with commercial telecommunication networks. For instance, a lot of attention has been paid to spectrum sensing as the front line functionality that needs to be completed in an efficient and accurate manner to enable an opportunistic CR network architecture. This is necessary to detect the existence of spectrum holes without which no other procedure can be fulfilled. However, simply sensing (cooperatively or not) the energy received from a primary transmitter cannot enable correct dynamic spectrum access. For example, the low strength of a primary transmitter's signal does not assure that there will be no interference to a nearby primary receiver. In addition, the presence of a primary transmitter's signal does not mean that CR network users cannot access the spectrum since there might not be any primary receiver in the vicinity. Despite the existing elegant and clever solutions to the DSA problem no robust, implementable scheme has emerged. In this paper, we challenge the basic premises of the proposed schemes. We further argue that addressing the technical challenges we face in deploying robust CR networks can only be achieved if we radically change the way we design their basic functionalities. In support of our argument, we present a set of real-world scenarios, inspired by realistic settings in commercial telecommunications networks, focusing on spectrum sensing as a basic and critical functionality in the deployment of CRs. We use these scenarios to show why existing DSA paradigms are not amenable to realistic deployment in complex wireless environments.Comment: Work in progres

An assessment of supply chain and innovation management practices in the manufacturing industries in Turkey

This paper aims at assessing the supply chain and innovation management in the manufacturing industries in Turkey on an empirical basis. The assessments presented are based on parts of the data and information collected through the execution of the Competitive Strategies and Best Practices Benchmarking Questionnaire in 82 companies from four sectors of the manufacturing industries in Turkey. Results of these sectoral benchmarking studies reported elsewhere indicate the need of adopting product differentiation particularly through more knowledge intensive products as the dominant competitive strategy and also the need for improvement in various areas of supply chain as well as innovation management. In this paper, these issues are analysed through the survey results and some conclusions are drawn. Several policy measures applicable in near future are suggested for improving the areas found in need of improvement

Knowledge Virtualization and Local Connectedness among Smart High-tech Companies

Smart high-tech companies are characterized by knowledge intensity and open innovation. Even when these companies emerge in spatial clusters or dense urban places, they may utilize knowledge networks on a global scale. However, there is not much insight into the factors that shape knowledge networks, the role of virtualization herein and the impact of on global knowledge sourcing on local connectedness. This paper seeks to fill these gaps in understanding, by drawing on a selected sample of young high-technology companies in the Netherlands and application of rough set analysis to identify homogeneous categories of companies in the highly differentiated segment of young high-tech companies. The outcomes suggest that employing mainly local and employing mainly global knowledge networks coexist in city-regions, and that only part of the globalized companies are losing local connectedness, particularly those involved in co-creation with global customers and those acting as learning partners of multinational corporations (‘reverse’ knowledge transfer). Factors counteracting a weakening of local connectedness are specific local knowledge relationships and the strategy of developing local/regional customer markets

Current capabilities, requirements and a proposed strategy for interdependency analysis in the UK

The UK government recently commissioned a research study to identify the state-of-the-art in Critical Infrastructure modelling and analysis, and the government/industry requirements for such tools and services. This study (Cetifs) concluded with a strategy aiming to bridge the gaps between the capabilities and requirements, which would establish interdependency analysis as a commercially viable service in the near future. This paper presents the findings of this study that was carried out by CSR, City University London, Adelard LLP, a safety/security consultancy and Cranfield University, defense academy of the UK