147 research outputs found

    Stabilität und Wandel von Arbeitsmarktinstitutionen aus wettbewerbsökonomischer Sicht

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    Dieser Beitrag fasst die Ergebnisse unserer industrieökonomischen, theoretischen Forschung zur Fragestellung von Stabilität und Wandel von Arbeitsmarktinstitutionen zusammen. Wir verfolgen dabei einen wettbewerbsökonomischen Forschungsansatz, der Marktmacht sowohl auf Arbeits- als auch auf Absatzmärkten unterstellt. In der Literatur hat sich hierfür der Begriff unionised oligopolies eingebürgert. Damit wird zum Ausdruck gebracht, dass die untersuchte Klasse von Modellen einerseits Verhandlungsmacht auf Arbeitsmärkten und andererseits unvollständigen Wettbewerb und somit Marktmacht auf Absatzmärkten berücksichtigt. Kern ist die Analyse der Wechselwirkungen zwischen Organisationsformen auf Arbeitsmärkten und Wettbewerbsverhältnissen auf Produktmärkten. Dabei analysieren wir aktuelle Entwicklungen auf dem deutschen Arbeitsmarkt wie die Einführung sektorspezifischer Mindestlöhne, die Rolle von Spartengewerkschaften, Formen der Gewinnbeteiligung von Arbeitnehmern sowie internationale Wettbewerbsaspekte wie die Verlagerung der Produktion durch internationale Unternehmen ins Ausland. -- This contribution gives an overview of the main results of our theoretical research on the stability and change of labour market institutions. We use so-called models of unionised oligopolies which are borrowed from the theory of industrial organization in order to analyse the effects of simultaneous market power in both labour and product markets. The focus of our research is on the interaction between various organisational structures of labour markets and different forms of product market competition. In particular, we analyse some current developments in Germany, such as the introduction of sector-specific minimum wages, the formation of craft unions, the increasing number of profit sharing contracts as well as the relocation of production facilities to foreign countries in the context of globalisation.

    A p-multigrid method enhanced with an ILUT smoother and its comparison to h-multigrid methods within Isogeometric Analysis

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    Over the years, Isogeometric Analysis has shown to be a successful alternative to the Finite Element Method (FEM). However, solving the resulting linear systems of equations efficiently remains a challenging task. In this paper, we consider a p-multigrid method, in which coarsening is applied in the approximation order p instead of the mesh width h. Since the use of classical smoothers (e.g. Gauss-Seidel) results in a p-multigrid method with deteriorating performance for higher values of p, the use of an ILUT smoother is investigated. Numerical results and a spectral analysis indicate that the resulting p-multigrid method exhibits convergence rates independent of h and p. In particular, we compare both coarsening strategies (e.g. coarsening in h or p) adopting both smoothers for a variety of two and threedimensional benchmarks

    A Simulation Suite for Lattice-Boltzmann based Real-Time CFD Applications Exploiting Multi-Level Parallelism on Modern Multi- and Many-Core Architectures

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    We present a software approach to hardware-oriented numerics which builds upon an augmented, previously published open-source set of libraries facilitating portable code development and optimisation on a wide range of modern computer architectures. In order to maximise eficiency, we exploit all levels of arallelism, including vectorisation within CPU cores, the Cell BE and GPUs, shared memory thread-level parallelism between cores, and parallelism between heterogeneous distributed memory resources in clusters. To evaluate and validate our approach, we implement a collection of modular building blocks for the easy and fast assembly and development of CFD applications based on the shallow water equations: We combine the Lattice-Boltzmann method with i-uid-structure interaction techniques in order to achieve real-time simulations targeting interactive virtual environments. Our results demonstrate that recent multi-core CPUs outperform the Cell BE, while GPUs are significantly faster than conventional multi-threaded SSE code. In addition, we verify good scalability properties of our application on small clusters

    A Simulation Suite for Lattice-Boltzmann based Real-Time CFD Applications Exploiting Multi-Level Parallelism on Modern Multi- and Many-Core Architectures

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    We present a software approach to hardware-oriented numerics which builds upon an augmented, previously published open-source set of libraries facilitating portable code development and optimisation on a wide range of modern computer architectures. In order to maximise eficiency, we exploit all levels of arallelism, including vectorisation within CPU cores, the Cell BE and GPUs, shared memory thread-level parallelism between cores, and parallelism between heterogeneous distributed memory resources in clusters. To evaluate and validate our approach, we implement a collection of modular building blocks for the easy and fast assembly and development of CFD applications based on the shallow water equations: We combine the Lattice-Boltzmann method with i-uid-structure interaction techniques in order to achieve real-time simulations targeting interactive virtual environments. Our results demonstrate that recent multi-core CPUs outperform the Cell BE, while GPUs are significantly faster than conventional multi-threaded SSE code. In addition, we verify good scalability properties of our application on small clusters

    An MPI-CUDA Implementation for Massively Parallel Incompressible Flow Computations on Multi-GPU Clusters

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    Modern graphics processing units (GPUs) with many-core architectures have emerged as general-purpose parallel computing platforms that can accelerate simulation science applications tremendously. While multi-GPU workstations with several TeraFLOPS of peak computing power are available to accelerate computational problems, larger problems require even more resources. Conventional clusters of central processing units (CPU) are now being augmented with multiple GPUs in each compute-node to tackle large problems. The heterogeneous architecture of a multi-GPU cluster with a deep memory hierarchy creates unique challenges in developing scalable and efficient simulation codes. In this study, we pursue mixed MPI-CUDA implementations and investigate three strategies to probe the efficiency and scalability of incompressible flow computations on the Lincoln Tesla cluster at the National Center for Supercomputing Applications (NCSA). We exploit some of the advanced features of MPI and CUDA programming to overlap both GPU data transfer and MPI communications with computations on the GPU. We sustain approximately 2.4 TeraFLOPS on the 64 nodes of the NCSA Lincoln Tesla cluster using 128 GPUs with a total of 30,720 processing elements. Our results demonstrate that multi-GPU clusters can substantially accelerate computational fluid dynamics (CFD) simulations

    HONEI: A collection of libraries for numerical computations targeting multiple processor architectures.

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    We present HONEI, an open-source collection of libraries offering a hardware oriented approach to numerical calculations. HONEI abstracts the hardware, and applications written on top of HONEI can be executed on a wide range of computer architectures such as CPUs, GPUs and the Cell processor. We demonstrate the flexibility and performance of our approach with two test applications, a Finite Element multigrid solver for the Poisson problem and a robust and fast simulation of shallow water waves. By linking against HONEI's libraries, we achieve a two-fold speedup over straight forward C++ code using HONEI's SSE backend, and additional 3--4 and 4--16 times faster execution on the Cell and a GPU. A second important aspect of our approach is that the full performance capabilities of the hardware under consideration can be exploited by adding optimised application-specific operations to the HONEI libraries. HONEI provides all necessary infrastructure for development and evaluation of such kernels, significantly simplifying their development
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