8,396 research outputs found

    Estimating the value of risk reduction for pedestrians in the road environment: An exploratory analysis

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    In recent years there has been a re-focus on the valuation of a statistical life from the ex post or human capital method to an ex ante willingness to pay (WTP) approach. This is in part a recognition that we need to focus on establishing the amount, ex ante, that individuals are willing to pay to reduce the risk of exposure to circumstances that might lead to death or degree of injury in the road environment. This study sets out a framework in which to identify the degree of preference heterogeneity in WTP of pedestrians to avoid being killed or injured. A stated choice experiment approach is developed. The empirical setting is a choice of walking route for a particular trip that a sample of pedestrians periodically undertakes in Australia. Mixed logit models are estimated to obtain the marginal (dis)utilities associated with each influence on the choice amongst the attribute packages offered in the stated choice scenarios. These conditional estimates are used to obtain the WTP distributions for fatality and classes of injury avoidance, which are then aggregated to obtain estimates for pedestrians of the value of risk reduction (VRR)

    Assessing Color Rendering in a 3d Setup

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    Abstract The Color-Rendering Index (CRI) for light source is a quantitative measure of the capability to preserve color appearance of illuminated objects. Recently, CRI has had a renewed interest because of the new LED systems, which usually have a CRI rather low, but a good preservation of color appearance and a pleasant visual appeal. This article presents an experiment performed by human observers to assess the appearance preservation of colors under a set of light sources. Results are then compared with a range of available color rendering indices, in order to assess CRIs variability relative to human judgment

    The Legal Considerations of Doing M&A with Chinese Companies

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    The first draft of this paper was presented at the Conference on Recent Issues on Corporate Law hosted by, held at the SNU Law Research Institute, on September 21, 2012.This Paper lines up the important issues which a foreign business or its attorney need to note when engaging in M&A with Chinese companies. In the context of either share or asset acquisition, China is bringing its rules more in line with the international standards. Nevertheless, certain specific points deserve attention and should not be taken for granted, while many others are still undergoing evolution. Some most recent development such as VIE is also reviewed

    Is dark energy an effect of averaging?

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    The present standard model of cosmology states that the known particles carry only a tiny fraction of total mass and energy of the Universe. Rather, unknown dark matter and dark energy are the dominant contributions to the cosmic energy budget. We review the logic that leads to the postulated dark energy and present an alternative point of view, in which the puzzle may be solved by properly taking into account the influence of cosmic structures on global observables. We illustrate the effect of averaging on the measurement of the Hubble constant.Comment: 9 pages, 2 figures; to appear in conference proceedings of ``Balkan workshop 2007", Kladovo (Serbia

    Intrinsic random walks in Riemannian and sub-Riemannian geometry via volume sampling

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    We relate some basic constructions of stochastic analysis to differential geometry, via random walk approximations. We consider walks on both Riemannian and sub-Riemannian manifolds in which the steps consist of travel along either geodesics or integral curves associated to orthonormal frames, and we give particular attention to walks where the choice of step is influenced by a volume on the manifold. A primary motivation is to explore how one can pass, in the parabolic scaling limit, from geodesics, orthonormal frames, and/or volumes to diffusions, and hence their infinitesimal generators, on sub-Riemannian manifolds, which is interesting in light of the fact that there is no completely canonical notion of sub-Laplacian on a general sub-Riemannian manifold. However, even in the Riemannian case, this random walk approach illuminates the geometric significance of Ito and Stratonovich stochastic differential equations as well as the role played by the volume

    Modelling consumers' heterogeneous preferences: a case study with Chilean wine consumers

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    Background and Aims: Understanding consumers' preferences is key to making a successful product, but preferences are heterogeneous. We compare three approaches to consider preference heterogeneity in discrete choice models: (i) systematic preference variations based on socio‐demographic characteristics; (ii) latent classes; and (iii) hybrid choice models with latent variables measuring consumers' attitudes. Methods and Results: Data from a stated choice survey of Chilean wine consumers were analysed using three different approaches; these agreed on average trends but differed in fit and implied different trade‐offs. For example, socio‐demographic characteristics correlate poorly with preferences. Latent classes offer a good fit but do not link preference heterogeneity to consumer characteristics. The hybrid choice model provides the best fit but requires more data, making it more difficult to use this approach in forecasting. Conclusions: The best approach might depend on the research objectives. Using latent classes on a representative sample is the best approach if forecasting is paramount. Modelling attitudes is helpful when more insight into consumers' preferences is sought. Systematic preference variations based on socio‐demographic characteristics are a good choice when only average trends are relevant. Significance of the Study: We make recommendations on how to model preference heterogeneity when studying wine preferences, an issue often overlooked

    Fabrication of Porous Scaffolds with a Controllable Microstructure and Mechanical Properties by Porogen Fusion Technique

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    Macroporous scaffolds with controllable pore structure and mechanical properties were fabricated by a porogen fusion technique. Biodegradable material poly (d, l-lactide) (PDLLA) was used as the scaffold matrix. The effects of porogen size, PDLLA concentration and hydroxyapatite (HA) content on the scaffold morphology, porosity and mechanical properties were investigated. High porosity (90% and above) and highly interconnected structures were easily obtained and the pore size could be adjusted by varying the porogen size. With the increasing porogen size and PDLLA concentration, the porosity of scaffolds decreases, while its mechanical properties increase. The introduction of HA greatly increases the impact on pore structure, mechanical properties and water absorption ability of scaffolds, while it has comparatively little influence on its porosity under low HA contents. These results show that by adjusting processing parameters, scaffolds could afford a controllable pore size, exhibit suitable pore structure and high porosity, as well as good mechanical properties, and may serve as an excellent substrate for bone tissue engineering

    Assessing color rendering in a 3d setup

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    The Color-Rendering Index (CRI) for light source is a quantitative measure of the capability to preserve color appearance of illuminated objects. Recently, CRI has had a renewed interest because of the new LED systems, which usually have a CRI rather low, but a good preservation of color appearance and a pleasant visual appeal. This article presents an experiment performed by human observers to assess the appearance preservation of colors under a set of light sources. Results are then compared with a range of available color rendering indices, in order to assess CRIs variability relative to human judgment

    The Hubble flow around the Local Group

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    We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 < D_LG < 3.0 Mpc, the Local flow is characterized by the Hubble parameter H_loc = (78+/-2) km/(s*Mpc), the mean-square peculiar velocity sigma_v = 25 km/s, corrected for errors of radial velocity measurements (~4 km/s) and distance measurements (~10 km/s), as well as the radius of the zero-velocity surface R_0 = (0.96+/-0.03) Mpc. The minimum value for sigma_v is achieved when the barycenter of the LG is located at the distance D_c = (0.55+/-0.05) D_M31 towards M31 corresponding to the Milky Way-to-M31 mass ratio M_MW / M_M31 ~ 4/5. In the reference frame of the 30 galaxies at 0.7 - 3.0 Mpc, the LG barycenter has a small peculiar velocity ~(24+/-4) km/s towards the Sculptor constellation. The derived value of R_0 corresponds to the total mass M_T(LG) = (1.9+/-0.2) 10^12 M_sun with Omega_m = 0.24 and a topologically flat universe, a value in good agreement with the sum of virial mass estimates for the Milky Way and M31.Comment: 14 pages, 6 figures, 1 table. Accepted for publication in MNRA
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