Pathways to social evolution: reciprocity, relatedness, and synergy

Many organisms live in populations structured by space and by class, exhibit plastic responses to their social partners, and are subject to non-additive ecological and fitness effects. Social evolution theory has long recognized that all of these factors can lead to different selection pressures but has only recently attempted to synthesize how these factors interact. Using models for both discrete and continuous phenotypes, we show that analyzing these factors in a consistent framework reveals that they interact with one another in ways previously overlooked. Specifically, behavioral responses (reciprocity), genetic relatedness, and synergy interact in non-trivial ways that cannot be easily captured by simple summary indices of assortment. We demonstrate the importance of these interactions by showing how they have been neglected in previous synthetic models of social behavior both within and between species. These interactions also affect the level of behavioral responses that can evolve in the long run; proximate biological mechanisms are evolutionarily stable when they generate enough responsiveness relative to the level of responsiveness that exactly balances the ecological costs and benefits. Given the richness of social behavior across taxa, these interactions should be a boon for empirical research as they are likely crucial for describing the complex relationship linking ecology, demography, and social behavior.Comment: 4 figure

Vulnerability to purely contagious balance of payment crises in emerging economies: An application to the cases of Russia, Turkey, and Brazil

We explore the possible role of interdependence of expectations in emerging market economies and analyze the crisis transmission mechanism within the ”pure”contagion framework. We consider the cases of Russia, Turkey, and Brazil, and assess whether the fundamentals of these countries allowed for the possibility of ”pure”contagion e¤ects from each other. In particular, we look at Russia - Turkey and Brazil - Russia pairs in year 1997 to see whether Brazilian and the Turkish economies exhibited vulnarability to pure contagion before the 1998 Russian crisis We also repeat the same exercise with the most recent 1999 data. The rationale for choosing these pairings is the huge volume of (luggage) trade between geographical neighbors Russia and Turkey, and the similar export structures of Russia and Brazil (predominantly raw materials) which are continents apart. Our results clearly indicate vulnerability of Brazilian and Turkish economies to high probability of crisis in Russia even in the face of improving fundamentals. In isolation, Brazilian and Turkish fundamentals were not weak enough to place them in a sure-crisis situation. With the incorporation of the Russian link, the multiple equilibria setting disappeared for both countries, rendering sure-crisis as the single equilibrium solution.contagion; balance of payment crisis; emerging economies; Turkey

Distributed multilevel optimization for complex structures

Optimization problems concerning complex structures with many design variables may entail an unacceptable computational cost. This problem can be reduced considerably with a multilevel approach: A structure consisting of several components is optimized as a whole (global) as well as on the component level. In this paper, an optimization method is discussed with applications in the assessment of the impact of new design considerations in the development of a structure. A strategy based on fully stressed design is applied for optimization problems in linear statics. A global model is used to calculate the interactions (e.g., loads) for each of the components. These components are then optimized using the prescribed interactions, followed by a new global calculation to update the interactions. Mixed discrete and continuous design variables as well as different design configurations are possible. An application of this strategy is presented in the form of the full optimization of a vertical tail plane center box of a generic large passenger aircraft. In linear dynamics, the parametrization of the component interactions is problematic due to the frequency dependence. Hence, a modified method is presented in which the speed of component mode synthesis is used to avoid this parametrization. This method is applied to a simple test case that originates from noise control. \u

Analyzing the solutions of DEA through information visualization and data mining techniques: SmartDEA framework

Data envelopment analysis (DEA) has proven to be a useful tool for assessing efficiency or productivity of organizations, which is of vital practical importance in managerial decision making. DEA provides a significant amount of information from which analysts and managers derive insights and guidelines to promote their existing performances. Regarding to this fact, effective and methodologic analysis and interpretation of DEA solutions are very critical. The main objective of this study is then to develop a general decision support system (DSS) framework to analyze the solutions of basic DEA models. The paper formally shows how the solutions of DEA models should be structured so that these solutions can be examined and interpreted by analysts through information visualization and data mining techniques effectively. An innovative and convenient DEA solver, SmartDEA, is designed and developed in accordance with the proposed analysis framework. The developed software provides a DEA solution which is consistent with the framework and is ready-to-analyze with data mining tools, through a table-based structure. The developed framework is tested and applied in a real world project for benchmarking the vendors of a leading Turkish automotive company. The results show the effectiveness and the efficacy of the proposed framework

Pricing when customers have limited attention

We study the optimal pricing problem of a firm facing customers with limited attention and capability to process information about the value (quality) of the offered products. We model customer choice based on the theory of rational inattention in the economics literature, which enables us to capture not only the impact of true qualities and prices, but also the intricate effects of customer's prior beliefs and cost of information acquisition and processing. We formulate the firm's price optimization problem and characterize the pricing and revenue implications of customer's limited attention. We test the robustness of our results under various modelling generalizations such as prices signaling quality and customer heterogeneity, and study extensions such as multiple products, competition, and joint inventory and pricing decisions. We also show that using alternative pricing policies that ignore the limited attention of customers or their ability to allocate this attention judiciously can potentially lead to significant profit losses for the firm. We discuss the managerial implications of our key findings and prescribe insights regarding information provision and product positioning

A taxonomy of logistics innovations

In this paper we present a taxonomy of supply chain and logistics innovations, which is based on an extensive literature survey. Our primary goal is to provide guidelines for choosing the most appropriate innovations for a company, such that the company can outrun its competitors. We investigate the factors, both internal and external to the company, that determine the applicability and effectiveness of the listed innovations. We support our suggestions with real world cases reported in literature

Pricing when customers have limited attention

We study the optimal pricing problem of a firm facing customers with limited attention and capability to process information about the value (quality) of the offered products. We model customer choice based on the theory of rational inattention in the economics literature, which enables us to capture not only the impact of true qualities and prices, but also the intricate effects of customer's prior beliefs and cost of information acquisition and processing. We formulate the firm's price optimization problem and characterize the pricing and revenue implications of customer's limited attention. We test the robustness of our results under various modelling generalizations such as prices signaling quality and customer heterogeneity, and study extensions such as multiple products, competition, and joint inventory and pricing decisions. We also show that using alternative pricing policies that ignore the limited attention of customers or their ability to allocate this attention judiciously can potentially lead to significant profit losses for the firm. We discuss the managerial implications of our key findings and prescribe insights regarding information provision and product positioning

Increasing productivity in high speed milling of airframe components using chatter stability diagrams

In this study, the application of chatter stability diagrams in industrial operations is presented with representative cases. Challenges arising due to the practical aspects of production systems are discussed in detail. Effects of tool, tool holder, spindle and CNC machine on chatter stability diagrams are presented. The implementation of the stability diagrams under such challenges is presented through real application examples showing significant reduction in machining times