Fully-implicit log-conformation formulation of constitutive laws

Subject of this paper is the derivation of a new constitutive law in terms of the logarithm of the conformation tensor that can be used as a full substitute for the 2D governing equations of the Oldroyd-B, Giesekus and other models. One of the key features of these new equations is that - in contrast to the original log-conf equations given by Fattal and Kupferman (2004) - these constitutive equations combined with the Navier-Stokes equations constitute a self-contained, non-iterative system of partial differential equations. In addition to its potential as a fruitful source for understanding the mathematical subtleties of the models from a new perspective, this analytical description also allows us to fully utilize the Newton-Raphson algorithm in numerical simulations, which by design should lead to reduced computational effort. By means of the confined cylinder benchmark we will show that a finite element discretization of these new equations delivers results of comparable accuracy to known methods.Comment: 21 pages, 5 figure

The Role of Multinational Enterprises in the Transition Process of Central and Eastern European Economies

Globalisering en de liberalisering van handel en kapitaalstromen hebben grote economische gevolgen in Centraal en Oost Europa, waar het economisch systeem na de val van de Muur opnieuw ingericht diende te worden. Het process van institutionele verandering, structurele economische transformatie en privatisering heeft zich in de verschillende landen van Centraal en Oosteuropa op verschillende wijzen ontwikkeld. De voormalige satellietstaten hebben een relatief snelle economische transformatie doorlopen en zijn lid geworden van de Europese Unie. De landen die lid waren van de ‘Commonwealth of Independent States’ (CIS) hadden daarentegen grote problemen met de transformatie naar een moderne markteconomie. Vanwege het gebrek aan kapitaal en relevante kennis hebben buitenlandse investeringen een cruciale role gespeeld bij het tranformatie proces in Centraal en OostEuropa.Deze dissertatie concentreert zich op de rol van multinationals bij het genoemde transitieproces. De dissertatie bestaat uit twee gedeelten. Allereerst wordt het locatie keuze gedrag van multinationals in Centraal en Oost Europa nader bestudeerd. Rekening houdend met de verschillende transitie paden die deze landen hebben doorlopen, suggereren mijn bevindingen dat buitenlandse investeringsbeslissingen deels padafhankelijk zijn, gedreven door agglomeratie voordelen en toegang tot inputs die slechts lokaal aanwezig zijn. Buitenlandse ondernemingen versterken daarmee de bestaande concentratie van economische activiteit.In het tweede gedeelte van de dissertatie analyseer ik de invloed van buitenlandse investeringen op de economie van het land waarin geinvesteerd wordt. Buitenlandse investeringen versterken de concurrentiepositie van locale bedrijven. Deze zogenaamde spillover effecten hangen af van de mate waarin de buitenlandse onderneming in de locale economie is ingebed en de mate waarin locale bedrijven. Tenslotte is het belangrijk op te merken dat de mate van kennis transfer van buitenlandse bedrijven naar lokale ondernemingen samenhangt met de mate waarin de buitenlandse onderneming is geintegreerd in wereldwijde productie netwerken, en veel minder met de mate waarin buitenlandse ondernemingen lokaal producten of diensten afnemen.The collapse of the communist system has initiated the transformation of Central and Eastern European (CEE) countries from a social-planned towards a market economy. The institutional transition, structural change and privatization process evolved at a different extent across CEE countries. The former satellite states implemented a rapid transformation of the economic system and joined the European Union (EU), whereas the countries of the Commonwealth of Independent States (CIS) faced severe difficulties in adapting their system to the new environment. Due to the lack of capital and knowledge, foreign direct investment (FDI) has played a crucial role in the process of technological renewal and economic development. This thesis consists of two research objectives; the location decision of multinational enterprises (MNE) in CEE regions and the impact of FDI in host economies. This thesis is based on firm level information and takes three theoretical frameworks on FDI into account: International Economics, Regional Economics and International Business. Taking the different transition paths of CEE countries into account, the findings suggest that the regional distribution of FDI differs across sectors and is affected by agglomeration economies and by the access to locally bounded inputs. Therefore, FDI amplifies the concentration of economic activities. The investigation of FDI spillovers provides evidence that FDI contributes to the competitiveness of domestic firms in CEE economies. Notwithstanding, the results show that local firms only benefit from FDI if foreign affiliates are sufficiently embedded in the host economy and global production networks

Automatic implementation of material laws: Jacobian calculation in a finite element code with TAPENADE

In an effort to increase the versatility of finite element codes, we explore the possibility of automatically creating the Jacobian matrix necessary for the gradient-based solution of nonlinear systems of equations. Particularly, we aim to assess the feasibility of employing the automatic differentiation tool TAPENADE for this purpose on a large Fortran codebase that is the result of many years of continuous development. As a starting point we will describe the special structure of finite element codes and the implications that this code design carries for an efficient calculation of the Jacobian matrix. We will also propose a first approach towards improving the efficiency of such a method. Finally, we will present a functioning method for the automatic implementation of the Jacobian calculation in a finite element software, but will also point out important shortcomings that will have to be addressed in the future.Comment: 17 pages, 9 figure

MNE’s Regional Location Choice - A Comparative Perspective on East Germany, the Czech Republic and Poland

The focus of this article is the empirical identification of factors influencing Foreign Direct Investment (FDI) in transition economies on a regional level (NUTS 2). The analysis is designed as benchmark between three neighboring post-communist regions, i.e. East Germany, the Czech Republic and Poland. Their different transition paths have not only resulted in economic differences. We can also observe today that the importance of pull factors for FDI varies significantly across the regions. This analysis shows that in comparison with Poland and the Czech Republic, East Germany’s major benefit is its purchasing power, its geographical proximity to West European markets, and its modern infrastructure. Furthermore, the analysis suggests that intra-industry linkages such as specialization and agglomeration economies are relevant factors for the location decision of foreign investors. This result can help to explain the regional divergence of FDI streams in transition economies.multinational enterprises, international business, regional economic activity: growth, development, and changes, discrete choice

Einflussfaktoren betrieblicher Innovationstätigkeit: Kleine Betriebe in Ostdeutschland mit viel Potenzial

Innovations in the sense of new products and production processes are crucial drivers of the economic development in advanced economies. After a phase of massive technological renewal in East Germany, characterized by much a higher rate of innovators in East than in West Germany, firms in East Germany have to compete with original innovation activities. The paper outlines the innovation activity in East and West Germany and investigates the determinants of product and process innovation within a multivariate analysis using the IAB establishment panel. The empirical study shows that firms in manufacturing industry in East Germany are quite active in innovation activities in the year 2008. As regards the share of innovative firms there are no substantial differences between East and West Germany. The regression analysis shows that R&D is a significant determinant of innovation in East and West for all types of innovation. In East Germany, further education activities for employees also show a statistically significant impact on innovation. A major difference between East and West could be found for the firm size. In East Germany size has no significant impact on innovation while in West Germany size clearly matters. Different from West Germany, small firms (10 up to 49 employees) in the East have a significantly positive impact on product innovations in the sense of market novelties.innovation, research and development, East Germany, West Germany

Theoretical Investigation on Injection Locking of the EU 170 GHz 2 MW TE34,19-Mode Coaxial-Cavity Gyrotron

Injection locking of gyrotron oscillators offers an improved mode stability and the precise phase and frequency control of the generated millimeter-wave signal. It might offer completely new possibilities for applications related to nuclear fusion plasma, spectroscopy, and radar. In this presentation it is shown that the theory of Kurokawa can be applied to understand the injection locking of gyrotrons and that it provides accurate prediction of the locking behavior. Based on that, the investigation on injection locking of the EU 170 GHz 2 MW TE 34,19 -mode coaxial-cavity gyrotron using self-consistent single and multimode simulations is presented. Detailed studies on injection signals containing competing modes to account either for signal impurities or for deliberate injection of competing modes are presented