12,078 research outputs found

    Diurnal forcing of planetary atmospheres

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    The utility of the Mars Planetary Boundary Layer Model (MPBL) for calculations in support of the Mars 94 balloon mission was substantially enhanced by the introduction of a balloon equation of motion into the model. Both vertical and horizontal excursions of the balloon are calculated along with its volume, temperature, and pressure. The simulations reproduce the expected 5-min vertical oscillations of a constant density balloon at altitude on Mars. The results of these calculations are presented for the nominal target location of the balloon. A nonlinear balanced model was developed for the Martian atmosphere. It was used to initialize a primitive equation model for the simulations of the Earth's atmosphere at the time of the El Chichon eruption in 1982. It is also used as an assimilation model to update the temperature and wind fields at frequent intervals

    Gauss congruences for rational functions in several variables

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    We investigate necessary as well as sufficient conditions under which the Laurent series coefficients fnf_{\boldsymbol{n}} associated to a multivariate rational function satisfy Gauss congruences, that is fmpr≡fmpr−1f_{\boldsymbol{m}p^r} \equiv f_{\boldsymbol{m}p^{r-1}} modulo prp^r. For instance, we show that these congruences hold for certain determinants of logarithmic derivatives. As an application, we completely classify rational functions P/QP/Q satisfying the Gauss congruences in the case that QQ is linear in each variable.Comment: 20 page

    Inheritance tax-exempt transfer of German businesses: Imperative or unjustified subsidy? An empirical analysis

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    This contribution addresses the substantial tax subsidies for businesses introduced by the German Inheritance Tax Act 2009. Advocates in favour of the vast or even entire tax exemption for businesses stress the potential damage of the inheritance tax on businesses, as those often lack liquid assets to meet tax liability. This submission tackles this issue empirically based on data of the German Inheritance Tax Statistics and the SOEP. The results indicate that former German inheritance tax law has not endangered transferred businesses. Hence, there is no need for the tremendous tax privilege for businesses in current German inheritance tax law. A virtual uniformed inheritance tax without tax privileges, which meets revenue neutrality per tax class according to current tax law, provokes in some cases relative high tax loads which might trouble businesses. --

    ENTREPRENEURSHIP EDUCATION: DO STUDENT-COMPANIES OFFER SUPERIOR VALUE?

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    An entrepreneurship course for academic students is expected to be a vital stimulus to promote entrepreneurship and the setup of creative new businesses. But do the students learn the right things? A comparison is made between the more classic “business plan” course and the setup of an actual student company.entrepreneurship, education, students

    Assessing the Non-Financial Predictors of the Success and Failure of Young Firms in the Netherlands

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    In this study, the Lussier (1995) success and failure prediction model is improved and tested on a sample of Dutch firms. Besides clearly defining a specific business plan, work experience is added as a variable, and contrary to previous researches, the discrete variables are dealt with appropriate this time. The results of this improved model show that product/service timing, planning, management experience, knowledge of marketing, economic timing, professional advice, and having a business partner are predictors of success and failure for young firms in the Netherlands.Business Planning, Small Business, and Success in Business

    Image Processing Algorithms for Driver Assistance using Wide Angle Cameras

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    Modern vehicles are deployed with a large number of sensors in order to provide a rich spectrum of driver assistance functionality. These systems enhance security and comfort of passengers and other traffic participants alike, but they also pave the road to fully autonomous traffic. In order to provide this functionality robustly and reliably, one currently makes use of numerous specialized sensors: laser, radar, ultrasound, and infrared sensors, as well as different kinds of video cameras. The diversity of sensors comes with high cost and enables complex assistance functions momentarily only for upper-class vehicles. The current research, thus, focuses on the development of better algorithms that make similar systems possible on inexpensive sensors. This thesis examines the aptitude of a new camera system, which has recently grown popular in vehicles of most of the large automobile manufacturers, for all major video-based driver assistance functionality. This so-called Topview system consists of four wide angle cameras with a view angle of up to 200 degrees, usually mounted at the front bumper, the two side mirrors and the trunk lid. By these means, one is able to provide a view surrounding the entire vehicle. However, the single camera images are distorted which substantiates the need for adapted image processing algorithms

    Dynamically affine maps in positive characteristic

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    We study fixed points of iterates of dynamically affine maps (a generalisation of Latt\`es maps) over algebraically closed fields of positive characteristic pp. We present and study certain hypotheses that imply a dichotomy for the Artin-Mazur zeta function of the dynamical system: it is either rational or non-holonomic, depending on specific characteristics of the map. We also study the algebraicity of the so-called tame zeta function, the generating function for periodic points of order coprime to pp. We then verify these hypotheses for dynamically affine maps on the projective line, generalising previous work of Bridy, and, in arbitrary dimension, for maps on Kummer varieties arising from multiplication by integers on abelian varieties.Comment: Lois van der Meijden co-authored Appendix B. 31 p

    Activity-Centric Computing Systems

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    ‱ Activity-Centric Computing (ACC) addresses deep-rooted information management problems in traditional application centric computing by providing a unifying computational model for human goal-oriented ‘activity,’ cutting across system boundaries. ‱ We provide a historical review of the motivation for and development of ACC systems, and highlight the need for broadening up this research topic to also include low-level system research and development. ‱ ACC concepts and technology relate to many facets of computing; they are relevant for researchers working on new computing models and operating systems, as well as for application designers seeking to incorporate these technologies in domain-specific applications
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