20,266 research outputs found

    Do institutions matter for technological change in transition economies? The case of the Russia's 89 regions and republics

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    We explore the impact of institutions on technological change in a transition economy. We use regional panel data for Russia's 89 regions and republics during the period of recovery and growth from 1998 to 2004 to show the impact of large variation in institutional development, ranging from full enforcement of property rights in the Northwest to red belt Communist regimes in the southeast. We find an unambiguous relationship between strong and sustained institutional development and technological change. We provide one model proxying the quality of institutions by the investment risk rating compiled by the rating agency ExpertRA Regions

    Should Mission Statements Be Promises? (And should they have to be?)

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    This paper explores how mission statements might become a resource for improving nonprofit governance and accountability. The author asks what legal duty or moral obligation nonprofit organizations should be under to articulate a mission statement that others (the government, donors, prospective beneficiaries, the public at large) could use to assess their goals and performance. The paper explores how mission statements might include auditable claims, rather than vague aspirations, and raises questions about how various stakeholders might be empowered to use mission statements in holding an organization to account.This publication is Hauser Center Working Paper No. 33.5. Hauser Working Paper Series Nos. 33.1-33.9 were prepared as background papers for the Nonprofit Governance and Accountability Symposium October 3-4, 2006

    SHARP simulation of discontinuities in highly convective steady flow

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    For steady multidimesional convection, the Quadratic Upstream Interpolation for Convective Kinematics (QUICK) scheme has several attractive properties. However, for highly convective simulation of step profiles, QUICK produces unphysical overshoots and a few oscillations, and this may cause serious problems in nonlinear flows. Fortunately, it is possible to modify the convective flux by writing the normalized convected control-volume face value as a function of the normalized adjacent upstream node value, developing criteria for monotonic resolution without sacrificing formal accuracy. This results in a nonlinear functional relationship between the normalized variables, whereas standard methods are all linear in this sense. The resulting Simple High Accuracy Resolution Program (SHARP) can be applied to steady multidimensional flows containing thin shear or mixing layers, shock waves, and other frontal phenomena. This represents a significant advance in modeling highly convective flows of engineering and geophysical importance. SHARP is based on an explicit, conservative, control-volume flux formation, equally applicable to one, two, or three dimensional elliptic, parabolic, hyperbolic, or mixed-flow regimes. Results are given for the bench-mark purely convective first-order results and the nonmonotonic predictions of second- and third-order upwinding

    Comparison of truncation error of finite-difference and finite-volume formulations of convection terms

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    Judging by errors in the computational-fluid-dynamics literature in recent years, it is not generally well understood that (above first-order) there are significant differences in spatial truncation error between formulations of convection involving a finite-difference approximation of the first derivative, on the one hand, and a finite-volume model of flux differences across a control-volume cell, on the other. The difference between the two formulations involves a second-order truncation-error term (proportional to the third-derivative of the convected variable). Hence, for example, a third (or higher) order finite-difference approximation for the first-derivative convection term is only second-order accurate when written in conservative control-volume form as a finite-volume formulation, and vice versa

    ULTRA-SHARP nonoscillatory convection schemes for high-speed steady multidimensional flow

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    For convection-dominated flows, classical second-order methods are notoriously oscillatory and often unstable. For this reason, many computational fluid dynamicists have adopted various forms of (inherently stable) first-order upwinding over the past few decades. Although it is now well known that first-order convection schemes suffer from serious inaccuracies attributable to artificial viscosity or numerical diffusion under high convection conditions, these methods continue to enjoy widespread popularity for numerical heat transfer calculations, apparently due to a perceived lack of viable high accuracy alternatives. But alternatives are available. For example, nonoscillatory methods used in gasdynamics, including currently popular TVD schemes, can be easily adapted to multidimensional incompressible flow and convective transport. This, in itself, would be a major advance for numerical convective heat transfer, for example. But, as is shown, second-order TVD schemes form only a small, overly restrictive, subclass of a much more universal, and extremely simple, nonoscillatory flux-limiting strategy which can be applied to convection schemes of arbitrarily high order accuracy, while requiring only a simple tridiagonal ADI line-solver, as used in the majority of general purpose iterative codes for incompressible flow and numerical heat transfer. The new universal limiter and associated solution procedures form the so-called ULTRA-SHARP alternative for high resolution nonoscillatory multidimensional steady state high speed convective modelling
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