Homogeneous and locally homogeneous solutions to symplectic curvature flow

J. Streets and G. Tian recently introduced symplectic curvature flow, a geometric flow on almost K\"ahler manifolds generalising K\"ahler-Ricci flow. The present article gives examples of explicit solutions to this flow of non-K\"ahler structures on several nilmanifolds and on twistor fibrations over hyperbolic space studied by J. Fine and D. Panov. The latter lead to examples of non-K\"ahler static solutions of symplectic curvature flow which can be seen as analogues of K\"ahler-Einstein manifolds in K\"ahler-Ricci flow.Comment: 15 page

Challenge to SME to Survive in Food Dynamic Markets: Innovation and Efficient Networks

The EU food entrepreneurs are facing dramatic changes in the competition arena. Globalization and liberalization processes are offering cheaper food products in international markets, either from countries with better comparative advantages or with more efficient marketing strategies. At the same time, food markets are in a process of continuous segmentation and changes. Consumers are located in different niches, according to socio-demographic variables, cultures and traditions. Some of them respond to price changes while others are more concerned with quality control and food safety. It is on this segment where typical products, traceability and denominations of origin have significant values. SME (Small and Medium Enterprises) have to survive on this competitive scenario using several strategies: focusing their attention on specific consumer segments (aged people, gourmets or ethnic groups), products (typical, denomination of origin) or with more personal attention. Their flexibility to adapt the production process should compensate the lack of economic and human resources and specialization activities. In the 21st century they may survive through adequate strategies, most of them based on several pillars: innovation, tradition and adequate network.Agribusiness, Industrial Organization, Marketing,

Fish Chain Performance in Madrid Market: An Empirical Analysis

Food chain analysis is becoming a useful instrument to increase efficiency. We focus the attention in the fish sector looking at the links from consumer to wholesalers in the region of Madrid. In order to get adequate information we developed face to face enquiries to the consumers, retailers and wholesalers. The analysis of the Madrid market give us a useful approach of the national and international sector, due to the fact that Mercamadrid is the biggest fish wholesale market in Europe, and the consumption in Madrid is representative in many ways of the Spanish market. Finally there are some conclusions and recommendations oriented toward the stakeholders.Fish, food chain, performance, competition, Agribusiness,

Meat safety as a tool of differentiation for retailers: Spanish and French examples of meat "supply chain brands"

The purpose of this article is to analyse how the health crises have contributed to increasing the segmentation of the supply of fresh and little-processed food products under the impetus of a reinforcement of regulations (affecting the supply chain as a whole) and of strategies adopted by the stakeholders. Indeed, since several food crises have strongly affected the production of animal food products, food safety has become one of the most important aspects of quality products for both consumers and retailers. The authors carry out an empirical and comparative analysis of the reactions of two neighbouring countries (Spain and France) faced with major health crises caused by similar events: the emergence of BSE cases. A special focus is made on the initiatives taken privately by two French retail groups (Carrefour and Auchan) operating in both countries. The analysis shows that retailers have developed systems of quality insurance developed in order to reduce uncertainty and to restore consumers’ confidence in the quality of the products they buy. These programmes of actions pave the way for policies of product differentiation. In a relatively different context from that of France, the two big French retail groups Carrefour and Auchan operating in Spain have developed similar approaches, which had not been the case in France. The paper provide useful keys for a better understanding of the strategies of retailers (use of "supply chain brands" as tools of differentiation to ensure consumers’ loyalty, marketing communication) in a context of sharp competition and of relative dissatisfaction with respect to «minimum quality» standards. \u

Making Racing Fun Through Player Modeling and Track Evolution

This paper addresses the problem of automatically constructing tracks tailor-made to maximize the enjoyment of individual players in a simple car racing game. To this end, some approaches to player modeling are investigated, and a method of using evolutionary algorithms to construct racing tracks is presented. A simple player-dependent metric of entertainment is proposed and used as the fitness function when evolving tracks. We conclude that accurate player modeling poses some significant challenges, but track evolution works well given the right track representation

Wage rigidity and disinflation in emerging countries

This paper examines the consequences of rapid disinflation for downward wage rigidities in two emerging countries, Brazil and Uruguay, relying on high quality matched employer-employee administrative data. Downward nominal wage rigidities are more important in Uruguay, while wage indexation is dominant in Brazil. Two regime changes are observed during the sample period, 1995-2004: (i) in Uruguay wage indexation declines, while workers'resistance to nominal wage cuts becomes more pronounced; and (ii) in Brazil, the introduction of inflation targeting by the Central Bank in 1999 shifts the focal point of wage negotiations from changes in the minimum wage to expected inflation. These regime changes cast doubts on the notion that wage rigidity is structural in the sense of Lucas (1976).Labor Markets,Income,Economic Theory&Research,Environmental Economics&Policies,Labor Policies

Normative Practical Reasoning via Argumentation and Dialogue

Postprin

A comparative study of several control techniques applied to a boost converter

In this paper a comparison among three control strategies is presented, with application to a boost DC-DC converter. The control strategies are developed on the switched boost circuit model and validated on the nonlinear model by use of simulations. The classical PID, a 2dof-IMC (two degree of freedom internal model controller) and an alternative controller - MAC (uprocessor advanced control) are applied, tested and compared on the nonlinear system. Additional tests show the robustness of the controllers on the highly nonlinear circuit