Evolutionary Games in Networked Populations: Models and Experiments

Cooperation and coordination are desirable behaviors that are fundamental for the harmonious development of society. People need to rely on cooperation with other individuals in many aspects of everyday life, such as teamwork and economic exchange in anonymous markets. However, cooperation may easily fall prey to exploitation by selfish individuals who only care about short- term gain. For cooperation to evolve, specific conditions and mechanisms are required, such as kinship, direct and indirect reciprocity through repeated interactions, or external interventions such as punishment. In this dissertation we investigate the effect of the network structure of the population on the evolution of cooperation and coordination. We consider several kinds of static and dynamical network topologies, such as Baraba´si-Albert, social network models and spatial networks. We perform numerical simulations and laboratory experiments using the Prisoner's Dilemma and co- ordination games in order to contrast human behavior with theoretical results. We show by numerical simulations that even a moderate amount of random noise on the Baraba´si-Albert scale-free network links causes a significant loss of cooperation, to the point that cooperation almost vanishes altogether in the Prisoner's Dilemma when the noise rate is high enough. Moreover, when we consider fixed social-like networks we find that current models of social networks may allow cooperation to emerge and to be robust at least as much as in scale-free networks. In the framework of spatial networks, we investigate whether cooperation can evolve and be stable when agents move randomly or performing Le´vy flights in a continuous space. We also consider discrete space adopting purposeful mobility and binary birth-death process to dis- cover emergent cooperative patterns. The fundamental result is that cooperation may be enhanced when this migration is opportunistic or even when agents follow very simple heuristics. In the experimental laboratory, we investigate the issue of social coordination between indi- viduals located on networks of contacts. In contrast to simulations, we find that human players dynamics do not converge to the efficient outcome more often in a social-like network than in a random network. In another experiment, we study the behavior of people who play a pure co- ordination game in a spatial environment in which they can move around and when changing convention is costly. We find that each convention forms homogeneous clusters and is adopted by approximately half of the individuals. When we provide them with global information, i.e., the number of subjects currently adopting one of the conventions, global consensus is reached in most, but not all, cases. Our results allow us to extract the heuristics used by the participants and to build a numerical simulation model that agrees very well with the experiments. Our findings have important implications for policymakers intending to promote specific, desired behaviors in a mobile population. Furthermore, we carry out an experiment with human subjects playing the Prisoner's Dilemma game in a diluted grid where people are able to move around. In contrast to previous results on purposeful rewiring in relational networks, we find no noticeable effect of mobility in space on the level of cooperation. Clusters of cooperators form momentarily but in a few rounds they dissolve as cooperators at the boundaries stop tolerating being cheated upon. Our results highlight the difficulties that mobile agents have to establish a cooperative environment in a spatial setting without a device such as reputation or the possibility of retaliation. i.e. punishment. Finally, we test experimentally the evolution of cooperation in social networks taking into ac- count a setting where we allow people to make or break links at their will. In this work we give particular attention to whether information on an individual's actions is freely available to poten- tial partners or not. Studying the role of information is relevant as information on other people's actions is often not available for free: a recruiting firm may need to call a job candidate's refer- ences, a bank may need to find out about the credit history of a new client, etc. We find that people cooperate almost fully when information on their actions is freely available to their potential part- ners. Cooperation is less likely, however, if people have to pay about half of what they gain from cooperating with a cooperator. Cooperation declines even further if people have to pay a cost that is almost equivalent to the gain from cooperating with a cooperator. Thus, costly information on potential neighbors' actions can undermine the incentive to cooperate in dynamical networks.

An overview on the Brazilian orange juice production chain

Brazil is the world's largest producer of oranges and uses more than 70% of the harvested fruits in the production of juices. The amount of processed orange is growing about 10% per year, confirming the trend of the Brazilian citrus for juice production. This research aimed to investigate the Brazilian orange juice production chain from 2005 to 2009. Data from the amount of frozen juice produced and exported, international price of orange juice, and intermediate transactions were assessed in order to make possible selection of all interveners involved in the chain. The study using the Social Network Analysis (SNA) showed that the densest relationships in the network are from exporters to importers and from orange growers to the orange processing industry. No difference was found in the values of the network geodesic distance or the clustering coefficients from 2005 to 2009. The degree of centrality increased steadily throughout the years indicating that the processing industry attempts to minimize the risks by centralizing the actions. A decrease in export of orange juice from 2007 (2.07 10(6) t) to 2008 (2.05 10(6) t) was found, probably due to the world's financial crisis with recovery in 2009. Since 2004, there has been an increase of nearly 10% per year in the market preference of concentrate juice (OFCJ) when compared to the "not from concentrated" juice (NFC). Nowadays the NFC market represents nearly 50% of all Brazilian export which impacted in the logistic distribution and transportation issues.

Fraktiointikerrostuksen vaikutus paperin laatuun

Työn tavoitteena oli kehittää prosessia fraktioinnista monikerrosperälaatikolle painopaperilajeilla. Tarkoituksena oli selvittää koeajojen avulla sihti- ja pyörrepuhdistusfraktioinnin soveltuvuutta paperin kerrostuksen kannalta. Työssä vertailtiin keskenään fraktiointimenetelmiä ja niiden yhdistelmiä. Tehtävänä oli prosessikonseptin kehittäminen eri prosessikytkennöistä ja –ratkaisuista simuloinnin avulla. Kirjallisuusosassa tutustuttiin analysoiden kirjallisuusviitteiden perusteella massan fraktiointiin ja paperin kerrostamiseen sekä fraktiointikerrostetun rainan karakterisointiin. Tavoitteiden saavuttamiseksi esikokeena suoritettiin pilotkoeajo hienopaperimassalla, jossa tutkittiin pääasiassa fraktiointitulosta. Toinen koeajo suoritettiin LWC-paperilla, jossa koekonekonsepti oli optimaalisempi kerrostuksen kannalta ja fraktiointitulos voitiin linkittää paperin laatusuureisiin. LWC-koeajossa fraktioidulla massalla tehtiin laboratoriomittakaavassa monikerrosarkkimuottikokeita, joiden tuloksilla pyrittiin vahvistamaan koeajosta saatuja tuloksia ja fraktioinnnin potentialia. Prosessikonseptin kehittämiseksi rakennettiin seitsemän simulointimallia eri kytkennöistä. Malleja verrattiin keskenään täyteaine- ja kuitujakeiden fraktiointikyvyn perusteella. Koeajojen avulla selvitettiin fraktioinnin kannalta optimaaliset prosessimuuttujat. Fraktiointikerrostuksella parannettiin paperin z-suuntaista lujuutta ja etenkin pyörrepuhdistinfraktioinnilla pintojen sileyttä. Fraktiointikerrostuksella voitiin parantaa paperin täyteainejakaumaa. Kokeiden perusteella huomattiin, että kukin paperilaji tarvitsee erilaisen fraktiointijärjestelyn riippuen käytetystä massasta ja täyteaineesta.

Tiimin sisäisen vuorovaikutuksen esteet ja edistäjät, case Etelä-Karjalan Osuuspankki

Tutkimuksen tavoitteena on löytää tekijöitä, jotka edistävät ja toisaalta estävät vuorovaikutusta tiimissä. Tutkimuksen managerialisena tavoitteena on luoda uusia sisäistä vuorovaikutusta edistäviä toimintatapoja kohdeorganisaation sijoitustiimissä. Teoreettisessa osassa tiimin sisäiseen vuorovaikutukseen vaikuttavia tekijöitä tarkastellaan tiimin sisäisen sosiaalisen pääoman, tiimin viestintävalmiuksien ja teknologisten ja sosiaalisten verkostorakenteiden kautta. Tutkimuksen empiirisessä osassa tarkastellaan kohdeyrityksen sijoitustiimin sisäisen vuorovaikutukseen tilaa ja selvitetään tekijöitä, jotka vaikuttavat vuorovaikutuksen myönteiseen kehittymiseen. Tutkimus osoittaa, että tiimin sisäinen sosiaalinen pääoma: verkostosuhteet, luottamus ja yhteiset pelisäännöt edistävät tiimin vuorovaikutusta. Sosiaaliset suhdeverkostot nousevat yhdeksi tärkeimmistä edistäjistä. Vuorovaikutuksen esteitä – tiimin hajautuneisuus ja kiire - voidaan minimoida sähköisten kommunikaatiovälineiden tarkoituksenmukaisella käytöllä. Esimiehen tärkeä rooli on näiden vuorovaikutusprosessien käynnistämisessä ja ylläpitämisessä.

Web didáctica para la aproximación de funciones mediante redes neuronales

In this article we presents a project [1] developed to demonstrate the capability that Multi-Layer Perceptrons (MLP) have to approximate non-linear functions [2]. The simulation has been implemented in Java to be used in all the computers by Internet [3], with a simple operation and pleasant interface. The power of the simulations is in the possibility of the user of seeing the evolutions of the approaches, the contribution of each neuron, the control of the different parameters, etc. In addition, to guide the user during the simulation, an online help has been implemented.

High-Speed Solid-Rotor Induction Machine – Electromagnetic Calculation and Design

Within the latest decade high-speed motor technology has been increasingly commonly applied within the range of medium and large power. More particularly, applications like such involved with gas movement and compression seem to be the most important area in which high-speed machines are used. In manufacturing the induction motor rotor core of one single piece of steel it is possible to achieve an extremely rigid rotor construction for the high-speed motor. In a mechanical sense, the solid rotor may be the best possible rotor construction. Unfortunately, the electromagnetic properties of a solid rotor are poorer than the properties of the traditional laminated rotor of an induction motor. This thesis analyses methods for improving the electromagnetic properties of a solid-rotor induction machine. The slip of the solid rotor is reduced notably if the solid rotor is axially slitted. The slitting patterns of the solid rotor are examined. It is shown how the slitting parameters affect the produced torque. Methods for decreasing the harmonic eddy currents on the surface of the rotor are also examined. The motivation for this is to improve the efficiency of the motor to reach the efficiency standard of a laminated rotor induction motor. To carry out these research tasks the finite element analysis is used. An analytical calculation of solid rotors based on the multi-layer transfer-matrix method is developed especially for the calculation of axially slitted solid rotors equipped with wellconducting end rings. The calculation results are verified by using the finite element analysis and laboratory measurements. The prototype motors of 250 – 300 kW and 140 Hz were tested to verify the results. Utilization factor data are given for several other prototypes the largest of which delivers 1000 kW at 12000 min-1.

Proximidad 2.0, el nuevo reto de la policía como servicio público

Este informe pretende efectuar un estudio en el cual se establezca un catálogo básico de elementos referentes para los servicios de atención a la ciudadanía y proximidad que en un futuro las policías ofrecerán a través de las redes sociales. Unas bases de esta tipología no podemos asentarla si no se tienen en consideración reflexiones multidisciplinares como por ejemplo la sociología, la política y la tecnología. En los últimos dos años las Redes Sociales o Social Network Sites (término en inglés) han ido transformándose, cada día más, en una herramienta indispensable no solo a nivel particular y personal, sino también a nivel empresarial, institucional y de representación colectiva.

Customer-Related Internal Communication in a Global Matrix Organization

The objective of the thesis was to explore the nature and characteristics of customer-related internal communication in a global industrial matrix organization during a specific customer relationship, and how it could be improved. The theoretical part of the study views the field of the concepts of intra-organizational information and knowledge sharing. The theoretical part also views the internal communications influences to customer relationships, its problematic, and the suggestions to improve internal communication in literature. The empirical part of the study was conducted with the Content Analysis and the Social Network Analysis as research methods. The data was collected by interviews and a questionnaire. Internal communication was observed first generally within the organization from the point of view of a certain business, and secondly, during a specific customer relationship at personal level and at departmental level. The results of the study describe the nature and characteristics of internal communication in the organization. The results give 13 suggestions for improving internal communication in the organization. Although the study has been done in one specific organization, it also offers insights for other organizations as well as managers to improve their internal communication.

Elders and the ITCs use to communicate with children and grandchildren

Past research in using ICTs (Information and Communication Technologies) in interpersonal communication showed that age plays an important role. There is a general assumption that the elderly are left behind regarding the adoption and the use of ICTs. Furthermore, elders tend to use ICTs mainly for instrumental purposes and the use is rather non-sophisticated. When elders are using ICTs to maintain their social network, similar patterns could be found: They start using internet, or intensify its use, when their children move abroad while they might decrease using the tool if the motivation ends. In this research we explore elders' incentives to go online and use internet services to communicate; the type of agencies they use to communicate with children and grandchildren abroad; and the situations that make them stop using the ICTs or even reject internet mediated communications. We base our discussion on the empirical evidence the two authors gathered in different cities and countries: Barcelona, Romania, Toronto, Los Angeles, Montevideo and Lima, through semi-structured interviews and observation, with people aged 60 years old and over. The results show that the ability for using ICT tools in an autonomous way is a better explanation than age. In this, we distinguish between assisted users and autonomous users. We found that oldest seniors and those seniors who are less socially active are more likely to be assisted users than those who are socially or professionally active. For them communication with their children and grandchildren abroad follows no agency or it is mediated by significant others from their local social network, who are able to use ICTs and select specific information to share, in the second step, with the elder. For some younger participants the use of ICTs is rather situational and imposed by their children or grandchildren, who installed the tool in the first place and assisted them in using it. Finally, other elders describe a proficient and independent use of ICTs so they use the devices and services the way they want to.We discuss the implications of the patterns in using ICTs, for elders' social life and their relationships with children and grandchildren. First, we emphasis the fact that those elders rejecting the ICTs or being unskilled in using them to communicate might be left out from their family circle, particularly when children are abroad -they would experience more isolation. Second, we underline the fact that when children and grandchildren are the ones that control the ICTs used by their parents and grandparents, they are controlling also the information flow and this will redefine the power relations between elders and their younger relatives.

Redes neurais e suas aplicações em calibração multivariada

Neural Networks are a set of mathematical methods and computer programs designed to simulate the information process and the knowledge acquisition of the human brain. In last years its application in chemistry is increasing significantly, due the special characteristics for model complex systems. The basic principles of two types of neural networks, the multi-layer perceptrons and radial basis functions, are introduced, as well as, a pruning approach to architecture optimization. Two analytical applications based on near infrared spectroscopy are presented, the first one for determination of nitrogen content in wheat leaves using multi-layer perceptrons networks and second one for determination of BRIX in sugar cane juices using radial basis functions networks.

PhD Students’ Research Group Networks: a Qualitative Approach

This article examines the networks within the research groups where Spanish PhD students are pursuing their doctorate. Capó et al. (2007) used quantitative data to predict PhD students’ publishing performance from their background, attitudes, supervisors’ performance and research group networks. Variables related to the research group network had a negligible explanatory power on student performance once the remaining variables had been accounted for. In this article, a qualitative follow up of the same students is carried out using extreme case sampling and indepth interviews. The qualitative research shows networking as important for students. Out of the 115 aspects that students mention in the interviews as relevant to publishing in the qualitative research, 92 have to do with their supervisors, their research group or their network as a whole. Similarly, out of the 50 hindrances mentioned, 20 have to do with the networks or relations. The most commonly mentioned network-related topics are research group members pushing PhD students to publish, meeting researchers outside the research group, existence of other PhD students in the group, help with the PhD from group members, supervisor’s interest in the thesis, the possibility of discussing with experts on the PhD’s topic and frequent contact with the supervisor and research group members. Some of these characteristics were not, however, measured in the conventional quantitative social network survey

Building the map of innovation for membrane materials (Ceramic membranes)

This work proposes a method of visualizing the trend of research in the field of ceramic membranes from 1999 to 2006. The presented approach involves identifying problems encountered during research in the field of ceramic membranes. Patents from US patent database and articles from Science Direct(& by ELSEVIER was analyzed for this work. The identification of problems was achieved with software Knowledgist which focuses on the semantic nature of a sentence to generate series of subject action object structures. The identified problems are classified into major research issues. This classification was used for the visualization of the intensity of research. The image produced gives the relation between the number of patents, with time and the major research issues. The identification of the most cited papers which strongly influence the research of the previously identified major issues in the given field was also carried out. The relations between these papers are presented using the metaphor of social network. The final result of this work are two figures, a diagram showing the change in the studied problems a specified period of time and a figure showing the relations between the major papers and groups of the problems

Hacia la autoformación permanente de los docentes en las comunidades de práctica: los talleres de internet en el Aula

El objetivo principal de este trabajo es determinar si las comunidades virtuales de práctica son un espacio adecuado para la autoformación de los docentes. Con este fin, primero se especifican algunos conceptos clave que ayuden a contextualizar el tema de la formación; en segundo lugar se recogen los rasgos que se consideran hoy necesarios para llevar a cabo la labor docente, dibujándose así el perfil “ideal” del profesor en el contexto actual desde distintos ángulos de vista; y por último, se narran algunas experiencias personales en las redes sociales para ilustrar el funcionamiento de este nuevo paradigma social.

Redes de colaboração científica na área de química no Brasil: um estudo baseado nas coautorias dos artigos da revista Química Nova

In this paper we built three co-authorship networks displaying the acquaintances between countries, universities and authors that have published papers in Quimica Nova from 1995 to 2008. Our research was conducted applying a bibliometric approach to 1782 papers and over 4200 authors. Centrality measures were used and the most significant actors of each network were pointed out. The results using the centrality metrics and the network structures indicated that Quimica Nova resembles a typical scientific community.