Differential Evolution with Enhanced Abilities for Adaptation Applied to Heterogeneous Numerical Optimization

This article presents an exploration of Differential Evolution (DE) algorithm with enhanced adaptability. The main purpose of this study is to identify how this search method can cope with changes of the number of variables of a hard design test, unaided. The results clearly show that this method successfully solves the explored functions

Status-Seeking in Hedonic Games with Heterogeneous Players

We study hedonic games with heterogeneous player types that reflect her nationality, ethnic background, or skill type. Agents' preferences are dictated by status-seeking where status can be either local or global. The two dimensions of status define the two components of a generalized constant elasticity of substitution utility function. In this setting, we characterize the core as a function of the utility's parameter values and show that in all cases the corresponding cores are non-empty. We further discuss the core stable outcomes in terms of their segregating versus integrating properties.Coalitions, Core, Stability, Status-seeking

Coalitional Matchings

A coalitional matching is a two-sided matching problem in which agents on each side of the market may form coalitions such as student groups and research teams who - when matched - form universities. We assume that each researcher has preferences over the research teams he would like to work in and over the student groups he would like to teach to. Correspondingly, each student has preferences over the groups of students he wants to study with and over the teams of researchers he would like to learn from. In this setup, we examine how the existence of core stable partitions on the distinct market sides, the restriction of agents’ preferences over groups to strict orderings, and the extent to which individual preferences respect common rankings shape the existence of core stable coalitional matchings.Coalitions, Common Rankings, Core, Stability, Totally Balanced Games, Two-Sided Matchings

Dynamic Multilateral Markets

We study dynamic multilateral markets, in which players’ payoffs result from coalitional bargaining. In this setting, we establish payoff uniqueness of the stationary equilibria when players exhibit some degree of impatience. We focus on market games with different player types, and derive under mild conditions an explicit formula for each type’s equilibrium payoff as market frictions vanish. The limit payoff of a type depends in an intuitive way on the supply and the demand for this type in the market, adjusted by the type-specific bargaining power. Our framework may be viewed as an alternative to the Walrasian price-setting mechanism. When we apply this methodology to the analysis of labor markets, we can determine endogenously the equilibrium firm size and remuneration scheme. We find that each worker type in a stationary market equilibrium is rewarded her marginal product, i.e. we obtain a strategic underpinning of the neoclassical wage. Interestingly, we can also replicate some standardized facts from the search-theoretical literature such as positive equilibrium unemployment.Multilateral Bargaining, Dynamic Markets, Labor Markets

Stability, Specialization and Social Recognition

Yang s theory of economic specialization under increasing returns to scale (Yang 2001) is a formal development of the fundamental Smith-Young theorem on the extent of the market and the social division of labor.In this theory specialization and, thus, the social division of labor is firmly embedded within a system of perfectly competitive markets.This leaves unresolved whether and how such development processes are possible in economies based on more primitive, nonmarket organizations.In this paper we introduce a general relational model of economic interaction.Within this non-market environment we discuss the emergence of economic specialization and ultimately of economic trade and a social division of labor.We base our approach on three stages in organizational development: the presence of a stable relational structure; the presence of relational trust and subjective specialization; and, finally, the emergence of objective specialization through the social recognition of subjectively defined economic rolesnetworks;stability;social division of labor;specialization

Stability, governance and effectiveness:Essays on the service economy

This thesis contains essays on the service economy. The issues studied in the essays are multifaceted. The main themes of stability, governance, and effectiveness are recurrent in different contexts: relational activities, group cooperation, country-level management and a very specific case of health care provision. The methodological tools employed are varied, too. In the theoretical essays, contributions are made to the literature on network and endogenous coalition formation. The empirical essays employ linear and non-linear regression models and use aggregate as well as micro-level data.

An Interoperable Clinical Cardiology Electronic Health Record System - a standards based approach for Clinical Practice and Research with Data Reuse

Currently in hospitals, several information systems manage, very often autonomously, the patient’s personal, clinical and diagnostic data. This originates a clinical information management system consisting of a myriad of independent subsystems which, although efficient in their specific purpose, make the integration of the whole system very difficult and limit the use of clinical data, especially as regards the reuse of these data for research purposes. Mainly for these reasons, the management of the Genoese ASL3 decided to commission the University of Genoa to set up a medical record system that could be easily integrated with the rest of the information system already present, but which offered solid interoperability features, and which could support the research skills of hospital health workers. My PhD work aimed to develop an electronic health record system for a cardiology ward, obtaining a prototype which is functional and usable in a hospital ward. The choice of cardiology was due to the wide availability of the staff of the cardiology department to support me in the development and in the test phase. The resulting medical record system has been designed “ab initio” to be fully integrated into the hospital information system and to exchange data with the regional health information infrastructure. In order to achieve interoperability the system is based on the Health Level Seven standards for exchanging information between medical information systems. These standards are widely deployed and allow for the exchange of information in several functional domains. Specific decision support sections for particular aspects of the clinical life were also included. The data collected by this system were the basis for examples of secondary use for the development of two models based on machine learning algorithms. The first model allows to predict mortality in patients with heart failure within 6 months from their admission, and the second is focused on the discrimination between heart failure versus chronic ischemic heart disease in the elderly population, which is the widest population section served by the cardiological ward