Split, characteristic based semi‐implicit algorithm for laminar/turbulent incompressible flows

In an earlier paper, Zienkiewicz and Codina (Int. j. numer. methods fluids, 20, 869–885 (1995)) presented a general algorithm for the solution of both compressible and incompressible Navier–Stokes equations. The algorithm, based on operator splitting, permits arbitrary interpolation functions to be used while avoiding the Babŭska–Brezzi restriction. In addition, its characteristic based approach introduces a form of rational dissipation. Zienkiewicz et al. (Int. j. numer. methods fluids, 20, 887–913 (1995)) presented the application of this algorithm in its fully explicit form to various inviscid compressible flow problems. They also presented two incompressible flow problems solved by the fully explicit form, employing a pseudo compressibility. The present work deals with the application of the above algorithm it its semi‐implicit form to some incompressible flow benchmark problems. Further, it extends the methodology to turbulent flows by employing both one, and two equation turbulence models. A comparison of results with earlier investigations is presented. Other issues addressed in this study include the effect of additional diffusion terms present in the scheme for both laminar and turbulent flow problems and some practical difficulties associated with local time stepping

Shock capturing viscosities for the general fluid mechanics algorithm

The performance of different shock capturing viscosities has been examined using our general fluid mechanics algorithm. Four different schemes have been tested, both for viscous and inviscid compressible flow problems. Results show that the methods based on the second gradient of pressure give better performance in all situations. For instance, the method constructed from the nodal pressure values and consistent and lumped mass matrices is an excellent choice for inviscid problems. The method based on L2 projection is better than any other method in viscous flow computations. The residual based anisotropic method gives excellent performance in the supersonic range and gives better results in the hypersonic regime if a small amount of residual smoothing is use

To be financed or not : the role of patents for venture capital financing

This paper investigates how patent applications and grants held by new ventures improve their ability to attract venture capital (VC) financing. We argue that investors are faced with considerable uncertainty and therefore rely on patents as signals when trying to assess the prospects of potential portfolio companies. For a sample of VC-seeking German and British biotechnology companies we have identified all patents filed at the European Patent Office (EPO). Applying hazard rate analysis, we find that in the presence of patent applications, VC financing occurs earlier. Our results also show that VCs pay attention to patent quality, financing those ventures faster which later turn out to have high-quality patents. Patent oppositions increase the likelihood of receiving VC, but ultimate grant decisions do not spur VC financing, presumably because they are anticipated. Our empirical results and interviews with VCs suggest that the process of patenting generates signals which help to overcome the liabilities of newness faced by new ventures

FE-SViT: A SViT-based fuzzy extractor framework

As a promising bio-cryptographic technique, the fuzzy extractor seamlessly binds biometrics and cryptography for template protection and key generation. However, most existing methods hardly solve the following issues simultaneously: (1) Fingerprint registration, (2) Verification accuracy, (3) Security strength, and (4) Computational efficiency. In this article, we introduce a bio-crypto-oriented fingerprint verification scheme - Selective Vertex-indexed Triangulation (SViT) which maps minutia global topology to local triangulation with minimum information loss. Then, a SViT-based fuzzy extractor framework (FE-SViT) is proposed and high verification accuracy is achieved. The FE-SViT is highly parallelizable and efficient which makes it suitable for embedded devices