42 research outputs found

    Fluence dependent femtosecond quasi-particle and Eu^{2+} -spin relaxation dynamics in EuFe_{2}(As,P)_{2}

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    We investigated temperature and fluence dependent dynamics of the time resolved optical reflectivity in undoped spin-density-wave (SDW) and doped superconducting (SC) EuFe2_{2}(As,P)2_{2} with emphasis on the ordered Eu2+^{2+}-spin temperature region. The data indicate that the SDW order coexists at low temperature with the SC and Eu2+^{2+}-ferromagnetic order. Increasing the excitation fluence leads to a thermal suppression of the Eu2+^{2+}-spin order due to the crystal-lattice heating while the SDW order is suppressed nonthermally at a higher fluence

    The determinants of managerial decisions under risk

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    In hierarchical organizations the role of a team leader often requires making decisions which do not necessarily coincide with the majority opinion of the team. However, these decisions are final and binding for all team members. We study experimentally why, and under which conditions, leaders resort to such decisions. In our experiment, teams are presented with several paired lottery choices. They decide by majority voting which lottery from the lottery pair they prefer to be played out. After all members of the team have made their choices, the team leader is informed about the outcome of the vote and has an opportunity either to confirm or to alter the majority decision. We find that leaders overrule their teams in 35% of cases and such decisions are primarily driven by divergent preferences of leaders and the other team members. Male, younger and more risk seeking (as opposed to female, older and more risk averse) leaders overrule decisions of ordinary team members more often. We discuss the implications of our findings for the management of organizations

    Contextual variety, Internet-of-Things and the choice of tailoring over platform: Mass customisation strategy in supply chain management

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    This is the final version. Available on open access from Elsevier via the DOI in this recordThis paper considers the implications for Supply Chain Management (SCM) from the development of the Internet of Things (IoT) or Internet Connected Objects (ICO). We focus on opportunities and challenges stemming from consumption data that comes from ICO, and on how this data can be mapped onto strategic choices of product variety. We develop a simple analytical framework that illustrates the underlying mechanisms of a product supplier/producer׳s choice between (i) producing multiple product varieties as a way of meeting consumer demand (a “tailoring strategy”), and (ii) offering a flexible and standardised platform which enables consumers׳ needs to be met by incorporating personal ICO data into various customisable applications (a “platform strategy”). Under a platform strategy, the ICO data is independently produced by other providers and can be called on in both use and context of use. We derive conditions under which each of the strategies may be profitable for the provider through maximising consumers’ value. Our findings are that the higher the demand for contextual variety, the more profitable the platform strategy becomes, relative to the tailoring strategy. Our study concludes by considering the implications for SCM research and practice with an extension to postponement taxonomies, including those where the customer, and not the supplier, is the completer of the product, and we show that this yields higher profits than the tailoring strategy.Engineering and Physical Sciences Research Council (EPSRC

    A COVID-19-based modified epidemiological model and technological approaches to help vulnerable individuals emerge from the lockdown in the UK

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    COVID-19 has shown a relatively low case fatality rate in young healthy individuals, with the majority of this group being asymptomatic or having mild symptoms. However, the severity of the disease among the elderly as well as in individuals with underlying health conditions has caused significant mortality rates worldwide. Understanding this variance amongst different sectors of society and modelling this will enable the different levels of risk to be determined to enable strategies to be applied to different groups. Long-established compartmental epidemiological models like SIR and SEIR do not account for the variability encountered in the severity of the SARS-CoV-2 disease across different population groups. The objective of this study is to investigate how a reduction in the exposure of vulnerable individuals to COVID-19 can minimise the number of deaths caused by the disease, using the UK as a case study. To overcome the limitation of long-established compartmental epidemiological models, it is proposed that a modified model, namely SEIR-v, through which the population is separated into two groups regarding their vulnerability to SARS-CoV-2 is applied. This enables the analysis of the spread of the epidemic when different contention measures are applied to different groups in society regarding their vulnerability to the disease. A Monte Carlo simulation (100,000 runs) along the proposed SEIR-v model is used to study the number of deaths which could be avoided as a function of the decrease in the exposure of vulnerable individuals to the disease. The results indicate a large number of deaths could be avoided by a slight realistic decrease in the exposure of vulnerable groups to the disease. The mean values across the simulations indicate 3681 and 7460 lives could be saved when such exposure is reduced by 10% and 20% respectively. From the encouraging results of the modelling a number of mechanisms are proposed to limit the exposure of vulnerable individuals to the disease. One option could be the provision of a wristband to vulnerable people and those without a smartphone and contact-tracing app, filling the gap created by systems relying on smartphone apps only. By combining very dense contact tracing data from smartphone apps and wristband signals with information about infection status and symptoms, vulnerable people can be protected and kept safer

    A COVID-19-Based Modified Epidemiological Model and Technological Approaches to Help Vulnerable Individuals Emerge from the Lockdown in the UK

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    COVID-19 has shown a relatively low case fatality rate in young healthy individuals, with the majority of this group being asymptomatic or having mild symptoms. However, the severity of the disease among the elderly as well as in individuals with underlying health conditions has caused significant mortality rates worldwide. Understanding this variance amongst different sectors of society and modelling this will enable the different levels of risk to be determined to enable strategies to be applied to different groups. Long-established compartmental epidemiological models like SIR and SEIR do not account for the variability encountered in the severity of the SARS-CoV-2 disease across different population groups. The objective of this study is to investigate how a reduction in the exposure of vulnerable individuals to COVID-19 can minimise the number of deaths caused by the disease, using the UK as a case study. To overcome the limitation of long-established compartmental epidemiological models, it is proposed that a modified model, namely SEIR-v, through which the population is separated into two groups regarding their vulnerability to SARS-CoV-2 is applied. This enables the analysis of the spread of the epidemic when different contention measures are applied to different groups in society regarding their vulnerability to the disease. A Monte Carlo simulation (100,000 runs) along the proposed SEIR-v model is used to study the number of deaths which could be avoided as a function of the decrease in the exposure of vulnerable individuals to the disease. The results indicate a large number of deaths could be avoided by a slight realistic decrease in the exposure of vulnerable groups to the disease. The mean values across the simulations indicate 3681 and 7460 lives could be saved when such exposure is reduced by 10% and 20% respectively. From the encouraging results of the modelling a number of mechanisms are proposed to limit the exposure of vulnerable individuals to the disease. One option could be the provision of a wristband to vulnerable people and those without a smartphone and contact-tracing app, filling the gap created by systems relying on smartphone apps only. By combining very dense contact tracing data from smartphone apps and wristband signals with information about infection status and symptoms, vulnerable people can be protected and kept safer

    Communication, leadership and coordination failure

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    We investigate the limits of communication and leadership in avoiding coordination failure in minimum effort games. Our environment is challenging, with low benefits of coordination relative to the effort cost. We consider two leader types: cheap-talk leader-communicators who suggest an effort level, and first-mover leaders who lead by example. Both types of leadership have some ability to increase effort in groups with no history, but are insufficient in groups with a history of low effort. Using the strategy method for followers’ responses, we attribute the persistence of coordination failure to the presence of followers who do not follow the leader
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