Re-Think Insurance: A New Perspective of InsurTech

Technology improves performances of industries generally. While some applications impact insurance industry profoundly, however, some of the improvement is more of office automation and is better not classified as InsurTech. The article is to provide a practical perspective of InsurTech from the review of definitions and purposes of insurance, and the induction of risk information and risk financing, to silhouette insurance ecosystem and framework of InsurTech. Under risk information, the information layering is explored and the basic three elements of risk, contract and portfolio are identified in insurance ecosystem; under risk financing, transaction costs of insurance and law of large numbers are applied. Then, we propose a framework based on the three elements for InsurTech in regard of availability, affordability and assurability. Two approaches are also proposed for InsurTech development - evolutionary way to revise specific areas of the current insurance models and revolutionary way to revamp the insurance models as to redesign the arrangement of risk protection

Surface Structure in an Accretion Disk Annulus with Comparable Radiation and Gas Pressure

We have employed a 3-d energy-conserving radiation MHD code to simulate the vertical structure and thermodynamics of a shearing box whose parameters were chosen so that the radiation and gas pressures would be comparable. The upper layers of this disk segment are magnetically-dominated, creating conditions appropriate for both photon bubble and Parker instabilities. We find little evidence for photon bubbles, even though the simulation has enough spatial resolution to see them and their predicted growth rates are high. On the other hand, there is strong evidence for Parker instabilities, and they appear to dominate the evolution of the magnetically supported surface layers. The disk photosphere is complex, with large density inhomogeneities at both the scattering and effective (thermalization) photospheres of the evolving horizontally-averaged structure. Both the dominant magnetic support and the inhomogeneities are likely to have strong effects on the spectrum and polarization of thermal photons emerging from the disk atmosphere. The inhomogeneities are also large enough to affect models of reflection spectra from the atmospheres of accretion disks.Comment: ApJ, in pres

Three-dimensional shelf circulation along an eastern ocean boundary

A linear, three-dimensional, continuously stratified model is used to study wind-driven ocean circulation near an eastern coast in the presence of a continental shelf. A simplifying assumption is that the alongshore flow field is in geostrophic balance. This assumption allows steady solutions to be obtained numerically with a very efficient scheme. As a result, it is possible to find solutions for a wide variety of model parameters and shelf profiles.A band of equatorward wind forces the ocean, and the resulting solutions have many features in common with observations at eastern boundaries. They all have a surface equatorward jet, but do not always have a coastal undercurrent. When the shelf depth is sufficiently shallow or vertical mixing is sufficiently strong, the speed of the undercurrent, if it exists, is usually weak; in that case, only when there is positive wind curl near the coast does its speed reach commonly observed values. Solutions are sensitive to the choice of bottom topographic profile. A general result is that the continental shelf always acts to strengthen the equatorward jet and to weaken or eliminate the undercurrent. The reason is that the shelf induces an equatorward barotropic component to the shelf currents, a component that is not present in flat-bottom solutions

Beating Stochastic and Adversarial Semi-bandits Optimally and Simultaneously

We develop the first general semi-bandit algorithm that simultaneously achieves $\mathcal{O}(\log T)$ regret for stochastic environments and $\mathcal{O}(\sqrt{T})$ regret for adversarial environments without knowledge of the regime or the number of rounds $T$. The leading problem-dependent constants of our bounds are not only optimal in some worst-case sense studied previously, but also optimal for two concrete instances of semi-bandit problems. Our algorithm and analysis extend the recent work of (Zimmert & Seldin, 2019) for the special case of multi-armed bandit, but importantly requires a novel hybrid regularizer designed specifically for semi-bandit. Experimental results on synthetic data show that our algorithm indeed performs well uniformly over different environments. We finally provide a preliminary extension of our results to the full bandit feedback