6,049 research outputs found

    The role of social media in the collaboration, interaction, co-creation and co-delivery of a social venture in an uncertain conflict environment

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    This research case study examines the creation and development of a bottom-up social enterprise immediately after the outbreak of a civil war in an Arab country by a group of young patriots in the aftermath of the Arab Spring uprisings in the 2010s. Drawing on Linders’ (2012) model of social action lifecycle, our study examines how different actors become involved and co-created a socially entrepreneurial venture (SEV), how these actors contributed to the coproduction and co-delivery of the social actions (values) over time, and how social media play roles in these processes. Drawing from the empirical evidences of citizen co-production within the existing literature, we found that SEVs operate in very different ways in which the role of social media is critical, both from their equivalents operating in a penurious but stable environment, and those intending to pursue political action within a conflict situation. In our case study, social media was not intended for mass-mobilisation, but for selected mobilisation amongst those within the network. This is due to the insecure environment and the fear of infiltration from opposing parties. We also examine how new actors were, over time, being carefully screened and selected, and potential harmful existing players being excluded, which in turn contributed to the evolving nature of the social enterprises

    Path-and Place-dependence of entrepreneurial ventures at times of war and conflict.

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    Studies have previously examined the path development of entrepreneurs within a penurious environment but what if their path encounters a conflict situation? Does it make the place even more resource-poor and subsequently squeeze out any remaining life from entrepreneurism? Utilising Isaksen?s (2014) characterisation of path-dependence, we intend to examine how entrepreneurs negotiate their path through the ?double whammy? of penurious environment and conflict. Through an event-based approach examining the entrepreneurial paths of three wartime entrepreneurs, our study indicates that, whilst the immediate aftermath is chaos leading to limited path-extension and even path-exhaustion, once the initial fog is clear, entrepreneurial individuals find different ways to adapt, not only through path-extension, but also through path-renewal and path-creation. These opportunities are place-dependent, the recognition of which requires considerable local knowledge and resources acquired through experience and prior local investment as well as interdependent networks

    Communications system evolutionary scenarios for Martian SEI support

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    In the Space Exploration Initiative (SEI) mission scenarios, expanding human presence is the primary driver for high data rate Mars-Earth communications. To support an expanding human presence, the data rate requirement will be gradual, following the phased implementation over time of the evolving SEI mission. Similarly, the growth and evolution of the space communications infrastructure to serve this requirement will also be gradual to efficiently exploit the useful life of the installed communications infrastructure and to ensure backward compatibility with long-term users. In work conducted over the past year, a number of alternatives for supporting high data rate Mars-Earth communications have been analyzed with respect to their compatibility with gradual evolution of the space communications infrastructure. The alternatives include RF, millimeter wave (MMW), and optical implementations, and incorporate both surface and space-based relay terminals in the Mars and Earth regions. Each alternative is evaluated with respect to its ability to efficiently meet a projected growth in data rate over time, its technology readiness, and its capability to satisfy the key conditions and constraints imposed by evolutionary transition. As a result of this analysis, a set of attractive alternative communications architectures have been identified and described, and a road map is developed that illustrates the most rational and beneficial evolutionary paths for the communications infrastructure

    Cooperative emission of a pulse train in an optically thick scattering medium

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    An optically thick cold atomic cloud emits a coherent flash of light in the forward direction when the phase of an incident probe field is abruptly changed. Because of cooperativity, the duration of this phenomena can be much shorter than the excited lifetime of a single atom. Repeating periodically the abrupt phase jump, we generate a train of pulses with short repetition time, high intensity contrast and high efficiency. In this regime, the emission is fully governed by cooperativity even if the cloud is dilute.Comment: 5 pages, 3 figure

    Wireless sensor network for cattle monitoring system

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    This paper describes a cost effective Wireless Sensor Network (WSN) technology for monitoring the health of dairy cows. By monitoring and understanding the cow individual and herd behaviour, farmers can potentially identify the onset of illness, lameness or other undesirable health conditions. However, the WSN implementation needs to cope with various technical challenges before it can be suitably and routinely applied in cow management. This paper discusses results concerning data transportation (i.e. mobility) from the cow mounted sensory devices

    Microwave vs optical crosslink study

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    The intersatellite links (ISL's) at geostationary orbit is currently a missing link in commercial satellite services. Prior studies have found that potential application of ISL's to domestic, regional, and global satellites will provide more cost-effective services than the non-ISL's systems (i.e., multiple-hop systems). In addition, ISL's can improve and expand the existing satellite services in several aspects. For example, ISL's can conserve the scarce spectrum allocated for fixed satellite services (FSS) by avoiding multiple hopping of the relay stations. ISL's can also conserve prime orbit slot by effectively expanding the geostationary arc. As a result of the coverage extension by using ISL's more users will have direct access to the satellite network, thus providing reduced signal propagation delay and improved signal quality. Given the potential benefits of ISL's system, it is of interest to determine the appropriate implementations for some potential ISL architectures. Summary of the selected ISL network architecture as supplied by NASA are listed. The projected high data rate requirements (greater than 400 Mbps) suggest that high frequency RF or optical implementations are natural approaches. Both RF and optical systems have their own merits and weaknesses which make the choice between them dependent on the specific application. Due to its relatively mature technology base, the implementation risk associated with RF (at least 32 GHz) is lower than that of the optical ISL's. However, the relatively large antenna size required by RF ISL's payload may cause real-estate problems on the host spacecraft. In addition, because of the frequency sharing (for duplex multiple channels communications) within the limited bandwidth allocated, RF ISL's are more susceptible to inter-system and inter-channel interferences. On the other hand, optical ISL's can offer interference-free transmission and compact sized payload. However, the extremely narrow beam widths (on the order of 10 micro-rad) associated with optical ISL's impose very stringent pointing, acquisition, and tracking requirements on the system. Even if the RF and optical systems are considered separately, questions still remain as to selection of RF frequency, direct versus coherent optical detection, etc. in implementing an ISL for a particular network architecture. These and other issues are studied

    Compulsory school-based enterprise education as a gateway to an entrepreneurial career

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    This article explores the direct influence of school-based enterprise education on career choices and particularly, how this might be limited as entrepreneurial intentions dissipate over time. We propose that it is the indirect influence of school-based enterprise education, through encouraging voluntary engagement with other forms of enterprise education, which is important. Drawing upon data from the United Kingdom (UK) Global Entrepreneurship Monitor (GEM) study this paper utilises a binary logistic regression approach and finds evidence to support the proposed indirect role. This shows the importance of collaboration between those delivering and designing enterprise education at all stages to ensure that young people are prepared correctly to move seamlessly between such stages

    Insecurity of position-based quantum cryptography protocols against entanglement attacks

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    Recently, position-based quantum cryptography has been claimed to be unconditionally secure. In contrary, here we show that the existing proposals for position-based quantum cryptography are, in fact, insecure if entanglement is shared among two adversaries. Specifically, we demonstrate how the adversaries can incorporate ideas of quantum teleportation and quantum secret sharing to compromise the security with certainty. The common flaw to all current protocols is that the Pauli operators always map a codeword to a codeword (up to an irrelevant overall phase). We propose a modified scheme lacking this property in which the same cheating strategy used to undermine the previous protocols can succeed with a rate at most 85%. We conjecture that the modified protocol is unconditionally secure and prove this to be true when the shared quantum resource between the adversaries is a two- or three- level system
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