The Importance of Co-ordination in National Technology Policy: Evidence From the Galileo Public Private Partnership.

Policy makers seek to identify an institutional framework that facilitates the commercialization of publicly funded R&D. In the space industry, the formation of such a framework is complicated by certain non-economic factors, such as national security considerations and the fact that numerous sovereign nations are often included in the commercialization process. In this paper, a model is outlined, that incorporates both economic and non-economic factors. The paper then demonstrates the importance of co-ordination in national technology policy to achieve an optimal result. The benefits of co-ordination are illustrated through a case study of the design of a major European public-private partnership (PPP) in the space industry, referred to as Galileo.

Cryptographic Key Management in Delay Tolerant Networks (DTNs): A survey

Since their appearance at the dawn of the second millennium, Delay or Disruption Tolerant Networks (DTNs) have gradually evolved, spurring the development of a variety of methods and protocols for making them more secure and resilient. In this context, perhaps, the most challenging problem to deal with is that of cryptographic key management. To the best of our knowledge, the work at hand is the first to survey the relevant literature and classify the various so far proposed key management approaches in such a restricted and harsh environment. Towards this goal, we have grouped the surveyed key management methods into three major categories depending on whether the particular method copes with a) security initialization, b) key establishment, and c) key revocation. We have attempted to provide a concise but fairly complete evaluation of the proposed up-to-date methods in a generalized way with the aim of offering a central reference point for future research

Opportunistic Key Management in Delay Tolerant Networks

Key Management is considered to be a challenging task in Delay Tolerant Networks (DTNs) operating in environments with adverse communication conditions such as space, due to the practical limitations and constraints prohibiting effective closed loop communications. In this paper we propose opportunistic key management as a more suitable solution for key management in networks requiring opportunistic behaviour. We show that opportunistic key management is better exploited and utilized when used in conjunction with routing decisions by security aware DTN nodes

Radiation-induced growth and isothermal decay of infrared-stimulated luminescence from feldspar

Optically stimulated luminescence (OSL) ages can determine a wide range of geological events or processes, such as the timing of sediment deposition, the exposure duration of a rock surface, or the cooling rate of bedrock. The accuracy of OSL dating critically depends on our capability to describe the growth and decay of laboratory-regenerated luminescence signals. Here we review a selection of common models describing the response of infrared stimulated luminescence (IRSL) of feldspar to constant radiation and temperature as administered in the laboratory. We use this opportunity to introduce a general-order kinetic model that successfully captures the behaviour of different materials and experimental conditions with a minimum of model parameters, and thus appears suitable for future application and validation in natural environments. Finally, we evaluate all the presented models by their ability to accurately describe a recently published feldspar multi-elevated temperature post-IR IRSL (MET-pIRIR) dataset, and highlight each model's strengths and shortfalls

1st International Workshop on Search and Mining Terrorist Online Content and Advances in Data Science for Cyber Security and Risk on the Web

The deliberate misuse of technical infrastructure (including the Web and social media) for cyber deviant and cybercriminal behaviour, ranging from the spreading of extremist and terrorism-related material to online fraud and cyber security attacks, is on the rise. This workshop aims to better understand such phenomena and develop methods for tackling them in an effective and efficient manner. The workshop brings together interdisciplinary researchers and experts in Web search, security informatics, social media analysis, machine learning, and digital forensics, with particular interests in cyber security. The workshop programme includes refereed papers, invited talks and a panel discussion for better understanding the current landscape, as well as the future of data mining for detecting cyber deviance

Distribution of Electric Currents in Solar Active Regions

There has been a long-lasting debate on the question of whether or not electric currents in solar active regions are neutralized. That is, whether or not the main (or direct) coronal currents connecting the active region polarities are surrounded by shielding (or return) currents of equal total value and opposite direction. Both theory and observations are not yet fully conclusive regarding this question, and numerical simulations have, surprisingly, barely been used to address it. Here we quantify the evolution of electric currents during the formation of a bipolar active region by considering a three-dimensional magnetohydrodynamic simulation of the emergence of a sub-photospheric, current-neutralized magnetic flux rope into the solar atmosphere. We find that a strong deviation from current neutralization develops simultaneously with the onset of significant flux emergence into the corona, accompanied by the development of substantial magnetic shear along the active region's polarity inversion line. After the region has formed and flux emergence has ceased, the strong magnetic fields in the region's center are connected solely by direct currents, and the total direct current is several times larger than the total return current. These results suggest that active regions, the main sources of coronal mass ejections and flares, are born with substantial net currents, in agreement with recent observations. Furthermore, they support eruption models that employ pre-eruption magnetic fields containing such currents.Comment: 6 pages, 5 figures, to appear in Astrophysical Journal Letter

The prisoners dilemma on a stochastic non-growth network evolution model

We investigate the evolution of cooperation on a non - growth network model with death/birth dynamics. Nodes reproduce under selection for higher payoffs in a prisoners dilemma game played between network neighbours. The mean field characteristics of the model are explored and an attempt is made to understand the size dependent behaviour of the model in terms of fluctuations in the strategy densities. We also briefly comment on the role of strategy mutation in regulating the strategy densties.Comment: 8 pages, 8 figure

On Minimal N=4 Topological Strings And The (1,k) Minimal Bosonic String

In this paper we consider tree-level scattering in the minimal N=4 topological string and show that a large class of N-point functions can be recast in terms of corresponding amplitudes in the (1,k) minimal bosonic string. This suggests a non-trivial relation between the minimal N=4 topological strings, the (1,k) minimal bosonic strings and their corresponding ADE matrix models. This relation has interesting and far-reaching implications for the topological sector of six-dimensional Little String Theories.Comment: lanlmac, 30 pages; v3 minor revisions, version published in JHE