188 research outputs found

    On the verge of Umdeutung in Minnesota: Van Vleck and the correspondence principle (Part One)

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    In October 1924, the Physical Review, a relatively minor journal at the time, published a remarkable two-part paper by John H. Van Vleck, working in virtual isolation at the University of Minnesota. Van Vleck combined advanced techniques of classical mechanics with Bohr's correspondence principle and Einstein's quantum theory of radiation to find quantum analogues of classical expressions for the emission, absorption, and dispersion of radiation. For modern readers Van Vleck's paper is much easier to follow than the famous paper by Kramers and Heisenberg on dispersion theory, which covers similar terrain and is widely credited to have led directly to Heisenberg's "Umdeutung" paper. This makes Van Vleck's paper extremely valuable for the reconstruction of the genesis of matrix mechanics. It also makes it tempting to ask why Van Vleck did not take the next step and develop matrix mechanics himself.Comment: 82 page

    Leadership and job satisfaction: addressing endogeneity with panel data from a field experiment

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    The interaction between leaders and employees plays a key role in determining organizational outcomes and performance. Although the human resources management literature posits positive effects of leadership behaviors on employee job satisfaction, the causal path between the two is unclear due to potential endogeneity issues inherent in this relationship. To address the issue, we first provide theoretical explanations about why and how transformational and transactional leadership behaviors would enhance employee job satisfaction. Second, we test the relationship between leadership behaviors and employee job satisfaction using panel data from a year-long randomized field experiment that engaged leaders and employees from hundreds of public and private organizations in Denmark. Primary findings suggest that although leadership training does not have direct effects on changes in employee job satisfaction, leadership-training-induced changes in leadership behaviors (transformational leadership and verbal rewards) are positively related to changes in job satisfaction

    Moment of Inertia and Quadrupole Response Function of a Trapped Superfluid

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    We derive an explicit relationship between the moment of inertia and the quadrupole response function of an interacting gas confined in a harmonic trap. The relationship holds for both Bose and Fermi systems and is well suited to reveal the effects of irrotationality of the superfluid motion. Recent experimental results on the scissors mode are used to extract the value of the moment of inertia of a trapped Bose gas and to point out the deviations from the rigid value due to superfluidity.Comment: 6 page

    Seeing eye to eye: can leadership training align perceptions of leadership?

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    There is a huge gap between how employees see leaders’ behavior and how leaders see themselves regardless of sector and functional area. Because this gap can be a serious problem in managing organizations, scholars have investigated how the gap can be reduced. This article focuses on leadership training and tests whether and under what conditions it narrows the gap. Using quantitative and qualitative data from a randomized field experiment with several hundred Danish leaders from public and private organizations, we find that a yearlong leadership training course decreases the differences between leader and employee perceptions of transformational and transactional leadership behaviors in public sector organizations but not in private organizations. The findings imply that leadership training can be one way for public organizations to align perceptions of leadership

    Interactive Marine Spatial Planning: Siting Tidal Energy Arrays around the Mull of Kintyre

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    The rapid development of the offshore renewable energy sector has led to an increased requirement for Marine Spatial Planning (MSP) and, increasingly, this is carried out in the context of the ‘ecosystem approach’ (EA) to management. We demonstrate a novel method to facilitate implementation of the EA. Using a real-time interactive mapping device (touch-table) and stakeholder workshops we gathered data and facilitated negotiation of spatial trade-offs at a potential site for tidal renewable energy off the Mull of Kintyre (Scotland). Conflicts between the interests of tidal energy developers and commercial and recreational users of the area were identified, and use preferences and concerns of stakeholders were highlighted. Social, cultural and spatial issues associated with conversion of common pool to private resource were also revealed. The method identified important gaps in existing spatial data and helped to fill these through interactive user inputs. The workshops developed a degree of consensus between conflicting users on the best areas for potential development suggesting that this approach should be adopted during MSP

    Spatial dimensions of stated preference valuation in environmental and resource economics: methods, trends and challenges

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    Pig farmers’ willingness to pay for management strategies to reduce aggression between pigs

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    When deciding whether to invest in an improvement to animal welfare, farmers must trade-off the relative costs and benefits. Despite the existence of effective solutions to many animal welfare issues, farmers’ willingness to pay for them is largely unknown. This study modelled pig farmers’ decisions to improve animal welfare using a discrete choice experiment focused on alleviating aggression between growing/finishing pigs at regrouping. Eighty-two UK and Irish pig farm owners and managers were asked to choose between hypothetical aggression control strategies described in terms of four attributes; installation cost, on-going cost, impact on skin lesions from aggression and impact on growth rate. If they did not like any of the strategies they could opt to keep their current farm practice. Systematic variations in product attributes allowed farmers’ preferences and willingness to pay to be estimated and latent class modelling accounted for heterogeneity in responses. The overall willingness to pay to reduce lesions was low at £0.06 per pig place (installation cost) and £0.01 per pig produced (running cost) for each 1% reduction in lesions. Results revealed three independent classes of farmers. Farmers in Class 1 were unlikely to regroup unfamiliar growing/finishing pigs, and thus were unwilling to adopt measures to reduce aggression at regrouping. Farmers in Classes 2 and 3 were willing to adopt measures providing certain pre-conditions were met. Farmers in Class 2 were motivated mainly by business goals, whilst farmers in Class 3 were motivated by both business and animal welfare goals, and were willing to pay the most to reduce aggression; £0.11 per pig place and £0.03 per pig produced for each 1% reduction in lesions. Farmers should not be considered a homogeneous group regarding the adoption of animal welfare innovations. Instead, campaigns should be targeted at subgroups according to their independent preferences and willingness to pay
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