Almeder C.,European University Viadrina |
Hartl R.F.,University of Vienna
International Journal of Production Economics | Year: 2013
This work deals with a scheduling problem of a real-world production process in the metal-working industry. The production process can be described as an offline stochastic flexible flow-shop problem with limited buffers. In a first step, we analyze a simplified model and develop a variable neighborhood search based solution approach where we use multiple scenarios to evaluate the objective. Second, the solution approach is adapted to a real-world case using a detailed discrete-event simulation to evaluate the production plans. We are able to improve state-of-the-art production plans statistically significant by 3-10%. © 2012 Elsevier B.V.
Breitmoser Y.,European University Viadrina
International Journal of Industrial Organization | Year: 2012
In many industries, firms pre-order input and forward sell output prior to the actual production period. It is known that forward buying input induces a "Cournot-Stackelberg endogeneity" (both Cournot and Stackelberg outcomes may result in equilibrium) and forward selling output induces a convergence to the Bertrand solution. I analyze the generalized model where firms pre-order input and forward sell output. First, I consider oligopolists producing homogenous goods, generalize the Cournot-Stackelberg endogeneity to oligopoly, and show that it additionally includes Bertrand in the generalized model. This shows that the "mode of competition" between firms may be entirely endogenous. Second, I consider duopolies producing heterogenous goods. The set of equilibrium outcomes is characterized and shown not to contain the Bertrand solution anymore. Yet, forward sales increase welfare also in this case, notably even when goods are complements. © 2011 Elsevier B.V. All rights reserved.
Walach H.,European University Viadrina
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2011
Control conditions were introduced through the trial of Mesmerism in Paris. Placebo controls became codified standard in 1946. Although seemingly unchallenged, there are various problems with this received view. The notion of a placebo is only defined from the negative. A positive notion proposed that placebo effects are effects owing to the meaning an intervention has for an individual. Thus, placebo effects are individualized, whereas standard research paradigms reveal only grossly averaged behaviour. Also, placebo effects are context sensitive, dependent on psychological factors such as expectancy, relief of stress and anxiety, and hence can generate strong and long-lasting treatment effects. These, however, are not predictable. Such a situation can lead to the efficacy paradox: sometimes, sham interventions can be more powerful than proved, evidence-based treatments. This situation has methodological consequences. Placebo-controlled randomized trials reveal only part of the answer, whether an intervention is effective. This is valuable information for regulators, but not necessarily also for patients and of limited value for providers. Hence, I have argued that we need to complement the hierarchical model of evidence by a circular one, in which various methods are employed on equal footing to answer different questions. © 2011 The Royal Society.
Kratke S.,European University Viadrina
European Urban and Regional Studies | Year: 2010
This article employs an actor network approach to the empirical analysis of knowledge networking in a case-study region in order to investigate the structure and properties of regional innovation networks in a detailed and nuanced way. Knowledge networks in terms of innovation-related cooperative interlinkages between firms and research establishments can be regarded as a relational component of regional innovation systems. The basic assumption is that connectivity in a regional knowledge network can positively contribute to a region's innovation capacity. The use of a social network analysis approach might enhance our understanding of knowledge networks in a regional context. This article presents the findings of a detailed network analysis of innovation-related cooperative interlinkages between public research establishments and private sector firms in a metropolitan region in Germany. © The Author(s), 2010.
Kratke S.,European University Viadrina
Urban Studies | Year: 2014
This article concentrates on the connectivity of global pharmaceutical and biotechnology firms in the contemporary 'world city network' that constitutes a 'space of flows' in which particular urban regions achieve an outstanding nodal centrality. World city network analyses have mostly concentrated on global service providers. Yet globally operating manufacturing firms also select distinct urban regions all across the world as locational anchoring points. Thus the network structures of distinct industrial sub-sectors need to be analysed in order to detect the differing nodal centralities and 'sectoral profiles' of cities functioning as geographical hubs of transnational production networks. A macro-scale analysis is presented of how the top 40 global firms in the pharmaceutical and biotechnology industry connected cities across the world in 2010. Subsequently, the nodal centralities of cities included in this sub-sector's global network are compared with the findings of previous analyses that concentrate on the advanced producer services sector. © 2013 Urban Studies Journal Limited.