2,619 research outputs found

    Five Women Wearing the Same Dress

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    Dynamic Splines with Constraints for Animation

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    In this paper, we present a method for fast interpolation between animation keyframes that allows for automatic computer-generated "improvement" of the motion. Our technique is closely related to conventional animation techniques, and can be used easily in conjunction with them for fast improvements of "rough" animations or for interpolation to allow sparser keyframing. We apply our technique to construction of splines in quaternion space where we show 100-fold speed-ups over previous methods. We also discuss our experiences with animation of an articulated human-like figure. Features of the method include: (1) Development of new subdivision techniques based on the Euler-Lagrange differential equations for splines in quaternion space; (2) An intuitive and simple set of coefficients to optimize over which is different from the conventional Bspline coefficients; (3) Widespread use of unconstrained minimization as opposed to constrained optimization needed by many previous methods. This speeds up the algorithm significantly, while still maintaining keyframe constraints accurately

    Social influences on flood preparedness and mitigation measures adopted by people living with flood risk

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    This paper aims to analyse evidence, based on one of the largest and most representative samples of households previously flooded or living with flood risk to date, of social patterns in a range of flood resilience traits relating to preparedness prior to a flood (e.g., property adaptations, contents insurance, etc.) and mitigations enacted during and immediately following a flood (e.g., receiving a warning, evacuation into temporary accommodation, etc.). The data were collected from a 2006 survey of 1223 households from a variety of locations across Scotland between one and twelve years after major local floods. Our analysis identifies remarkably few social differences in flood preparedness and mitigation measures, although some aspects of demography, housing and length of residence in an area, as well as personal flood history, are important. In light of this finding, we argue that social differences in vulnerability and resilience to flooding arise from deep-seated socio-economic and socio-spatial inequalities that affect exposure to flood risk and ability to recover from flood impacts. The engrained, but well-meaning, assumption in flood risk management that impoverished households and communities are lacking or deficient in flood preparedness or mitigation knowledge and capabilities is somewhat pejorative and misses fundamental, yet sometimes invisible, social stratifications play out in subtle but powerful ways to affect households’ and communities’ ability to avoid and recover from floods. We argue that general poverty and inequality alleviation measures, such as tax and welfare policy and urban and community regeneration schemes, are likely to be as, if not more, important in alleviating social inequalities in the long-term impacts of floods than social targeting of flood risk management policy

    Social networks : the future for health care delivery

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    With the rapid growth of online social networking for health, health care systems are experiencing an inescapable increase in complexity. This is not necessarily a drawback; self-organising, adaptive networks could become central to future health care delivery. This paper considers whether social networks composed of patients and their social circles can compete with, or complement, professional networks in assembling health-related information of value for improving health and health care. Using the framework of analysis of a two-sided network – patients and providers – with multiple platforms for interaction, we argue that the structure and dynamics of such a network has implications for future health care. Patients are using social networking to access and contribute health information. Among those living with chronic illness and disability and engaging with social networks, there is considerable expertise in assessing, combining and exploiting information. Social networking is providing a new landscape for patients to assemble health information, relatively free from the constraints of traditional health care. However, health information from social networks currently complements traditional sources rather than substituting for them. Networking among health care provider organisations is enabling greater exploitation of health information for health care planning. The platforms of interaction are also changing. Patient-doctor encounters are now more permeable to influence from social networks and professional networks. Diffuse and temporary platforms of interaction enable discourse between patients and professionals, and include platforms controlled by patients. We argue that social networking has the potential to change patterns of health inequalities and access to health care, alter the stability of health care provision and lead to a reformulation of the role of health professionals. Further research is needed to understand how network structure combined with its dynamics will affect the flow of information and potentially the allocation of health care resources

    Natural flood management, lag time and catchment scale:Results from an empirical nested catchment study

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    Natural flood management (NFM) techniques attract much interest in flood risk management science, not least because their effectiveness remains subject to considerable uncertainty, particularly at larger catchment and event scales. This derives from a paucity of empirical studies which can offer either longitudinal or comparison data sets in which changes can be observed. The Eddleston catchment study, with 13 stream gauges operated continuously over 9 years, is based on both longitudinal and comparison data sets. Two years of baseline monitoring have been followed by 7 years of further monitoring after a range of NFM interventions across the 69 km2 catchment. This study has examined changes in lag as an index of hydrological response which avoids dependence on potentially significant uncertainties in flow data. Headwater catchments up to 26 km2 showed significant delays in lag of 2.6–7.3 hr in catchments provided with leaky wood structures, on‐line ponds and riparian planting, while larger catchments downstream and those treated with riparian planting alone did not. Two control catchments failed to show any such changes. The findings provide important evidence of the catchment scale at which NFM can be effective and suggest that effects may increase with event magnitude

    Heavy Quarks from QCD Spectral Sum Rules

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    This is a short review of the present status of the dynamics of the heavy quarks extracted from QCD spectral sum rules. We discuss the determination of the ``perturbative" quark mass, the decay constants of the DD and BB mesons, the form factors of the semileptonic and radiative decays of the BB mesons, the slope of the Isgur--Wise function and the emerged value of VcbV_{cb}. We mention shortly some properties of the hybrid and BcB_c mesons.Comment: CERN-TH 7277/94, Updated version. Latex file (run twice). Talk given at the {\it XXIXth Rencontre de Moriond on `` QCD and High Energy Hadronic Interactions"}, M\'eribel, Haute-Savoie, 19--26th March 1994 and at the {\it Rencontre entre experimentateurs et theoriciens sur ``la violation de CP"}, Orsay, 6--7th May 199

    Scepticism about moral superiority

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    Chapman & Huffman suggest that we might change people’s behavior toward animals by resisting an argument that because humans are intellectually superior to animals they are also morally superior to animals. C & H try to show that the premise is false: Humans are not intellectually superior. Several commentators have resisted this response. We suggest that there are other ways of attacking the argument: The notion of moral superiority on which the argument relies is dubious, and the obvious ways of reformulating the argument are instances of the “naturalistic fallacy.”Publisher PDFNon peer reviewe

    Moment bounds for the Smoluchowski equation and their consequences

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    We prove uniform bounds on moments X_a = \sum_{m}{m^a f_m(x,t)} of the Smoluchowski coagulation equations with diffusion, valid in any dimension. If the collision propensities \alpha(n,m) of mass n and mass m particles grow more slowly than (n+m)(d(n) + d(m)), and the diffusion rate d(\cdot) is non-increasing and satisfies m^{-b_1} \leq d(m) \leq m^{-b_2} for some b_1 and b_2 satisfying 0 \leq b_2 < b_1 < \infty, then any weak solution satisfies X_a \in L^{\infty}(\mathbb{R}^d \times [0,T]) \cap L^1(\mathbb{R}^d \times [0,T]) for every a \in \mathbb{N} and T \in (0,\infty), (provided that certain moments of the initial data are finite). As a consequence, we infer that these conditions are sufficient to ensure uniqueness of a weak solution and its conservation of mass.Comment: 30 page
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