Redes interorganizacionais e inovação: o caso do pólo joalheiro de Belém

This work is a case study based on Belém Jewelry Pole, whose main issue is to understand how the social network (which the Pole is inserted) influences on innovation process on this area. The main objective is to analyze how interorganizational networks impacted/impact on the potential for innovation, creating both limits and opportunities for the companies development. The adopted method analyzed the historical jewelry industry trajectory since the beginning of mineral extraction in the city of Itaituba (in the Pará State) until nowadays. Primary and secondary data were used allowing the view of the dynamics of the network during transformation periods of the main involved actors in the process. The prospect of embeddedness structural as analysis technique allowed verifying the quality of interactors ties, as well as the visualization of their structures. During the jewelry industry trajectory was verified a change in the quality of social relations, modifying the information flow, trust and associations of various links in the production chain. Both direct and indirect ties facilitated the access to remote networks entering new information related to new products, processes and market aspects. This interaction has led to raising the innovation potential causing a qualitative and quantitative improvement in competitiveness of organizations. Some embedded ties allowed the formation of partnerships bringing various economic earnings for those involved in the relationship. Thus, it is understood how aspects related to the position, architecture and quality of ties in a wide social network influenced on the innovation process and eventual jewelry industry trajectory

Análise estequiométrica da dinâmica não-linear de redes de reações químicas

Dissertação (mestrado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Química, 2016.

Análise de risco para computação em nuvem

Têm-se notado nos últimos anos um crescimento na adoção de tecnologias de computação em nuvem, com uma adesão inicial por parte de particulares e pequenas empresas, e mais recentemente por grandes organizações. Esta tecnologia tem servido de base ao aparecimento de um conjunto de novas tendências, como a Internet das Coisas ligando os nossos equipamentos pessoais e wearables às redes sociais, processos de big data que permitem tipificar comportamentos de clientes ou ainda facilitar a vida ao cidadão com serviços de atendimento integrados. No entanto, tal como em todas as novas tendências disruptivas, que trazem consigo um conjunto de oportunidades, trazem também um conjunto de novos riscos que são necessários de serem equacionados. Embora este caminho praticamente se torne inevitável para uma grande parte de empresas e entidades governamentais, a sua adoção como funcionamento deve ser alvo de uma permanente avaliação e monitorização entre as vantagens e riscos associados. Para tal, é fundamental que as organizações se dotem de uma eficiente gestão do risco, de modo que possam tipificar os riscos (identificar, analisar e quantificar) e orientar-se de uma forma segura e metódica para este novo paradigma. Caso não o façam, os riscos ficam evidenciados, desde uma possível perda de competitividade face às suas congéneres, falta de confiança dos clientes, dos parceiros de negócio e podendo culminar numa total inatividade do negócio. Com esta tese de mestrado desenvolve-se uma análise genérica de risco tendo como base a Norma ISO 31000:2009 e a elaboração de uma proposta de registo de risco, que possa servir de auxiliar em processos de tomada de decisão na contratação e manutenção de serviços de Computação em Nuvem por responsáveis de organizações privadas ou estatais.

The specific shapes of gender imbalance in scientific authorships : a network approach

Gender differences in collaborative research have received little at- tention when compared with the growing importance that women hold in academia and research. Unsurprisingly, most of bibliomet- ric databases have a strong lack of directly available information by gender. Although empirical-based network approaches are often used in the study of research collaboration, the studies about the influence of gender dissimilarities on the resulting topological outcomes are still scarce. Here, networks of scientific subjects are used to characterize patterns that might be associated to five categories of authorships which were built based on gender. We find enough evidence that gen- der imbalance in scientific authorships brings a peculiar trait to the networks induced from papers published in Web of Science (WoS) in- dexed journals of Economics over the period 2010-2015 and having at least one author affiliated to a Portuguese institution. Our re- sults show the emergence of a specific pattern when the network of co-occurring subjects is induced from a set of papers exclusively au- thored by men. Such a male-exclusive authorship condition is found to be the solely responsible for the emergence that particular shape in the network structure. This peculiar trait might facilitate future network analyses of research collaboration and interdisciplinarity.

A utilização das redes sociais pela Guarda Nacional Republicana no âmbito da prevenção rodoviária

Sabendo que grande parte do combate ao flagelo que é a sinistralidade rodoviária, passa pela prevenção e que as redes sociais são ferramentas cada vez mais utilizadas no quotidiano, pela sociedade, tendo passado a ser um veículo cada vez mais utilizado para comunicar com as pessoas, surge a presente investigação intitulada: “A utilização das redes sociais pela Guarda Nacional Republicana no âmbito da Prevenção Rodoviária”. O objetivo geral do presente Trabalho de Investigação Aplicada, é determinar o contributo da utilização das redes sociais na divulgação da Prevenção Rodoviária, por parte da Guarda Nacional Republicana. Nesta investigação adotou-se o método hipotético-dedutivo tendo-se a presente investigação desenvolvido em três fases: exploratória, analítica e conclusiva. A primeira fase consiste num levantamento bibliográfico e documental. A segunda fase consiste em análise documental, na recolha e tratamento de dados resultantes da realização de entrevistas, e na respetiva apresentação, análise e discussão dos mesmos, respondendo-se ainda às hipóteses de investigação, lançadas no início da investigação. Na terceira fase, responde-se às perguntas derivadas e à pergunta de partida, frisando ainda algumas dificuldades sentidas durante a realização desta investigação. Assim, conclui-se que ao aderir às redes sociais, a instituição passou a ser um ator ativo e autónomo no processo de comunicação, não necessitando constantemente da comunicação social para passar determinada mensagem. A instituição pode e deve complementar e tomar a iniciativa, em situações em que a comunicação social dê uma importância redutora a certas campanhas, relevando o papel da utilização das redes sociais, sendo possível atingir números bastante consideráveis de pessoas. Além disso, passou a ser possível pôr em prática campanhas e ações de autoria própria, elevando assim o nome da Guarda, tornando-a num produto “apetecível” para a comunicação social, fazendo com que venham ter com a instituição e estejam interessados em que esta faça parte do seu tempo de antena, especialmente da televisão.

Regulation of microgeneration and microgrids

The concept of microgrid (μGrid) has been emerging as a way to integrate microgeneration (μG) in low-voltage (LV) networks and simultaneously improve its potential benefits. Technical requirements to connect μgrids to LV networks have been studied in order to make this concept technologically feasible and safe to operate. However, the regulatory framework for economic integration of μG and μGrids on distribution systems, despite being crucial, is still an open issue. The main purpose of this paper is to contribute for the development of an appropriate economic regulation framework that removes the barriers to μG and μGrid development. To do so, the relevant costs and benefits resulting from the establishment of μG and μGrid are identified and a methodology for sharing those costs and benefits among the involved economic agents is presented. The only pre-requisite of such a methodology is the existence of a net benefit to all economic agents.

Query routing in cooperative semi-structured peer-to-peer information retrieval networks

Conventional web search engines are centralised in that a single entity crawls and indexes the documents selected for future retrieval, and the relevance models used to determine which documents are relevant to a given user query. As a result, these search engines suffer from several technical drawbacks such as handling scale, timeliness and reliability, in addition to ethical concerns such as commercial manipulation and information censorship. Alleviating the need to rely entirely on a single entity, Peer-to-Peer (P2P) Information Retrieval (IR) has been proposed as a solution, as it distributes the functional components of a web search engine – from crawling and indexing documents, to query processing – across the network of users (or, peers) who use the search engine. This strategy for constructing an IR system poses several efficiency and effectiveness challenges which have been identified in past work. Accordingly, this thesis makes several contributions towards advancing the state of the art in P2P-IR effectiveness by improving the query processing and relevance scoring aspects of a P2P web search. Federated search systems are a form of distributed information retrieval model that route the user’s information need, formulated as a query, to distributed resources and merge the retrieved result lists into a final list. P2P-IR networks are one form of federated search in routing queries and merging result among participating peers. The query is propagated through disseminated nodes to hit the peers that are most likely to contain relevant documents, then the retrieved result lists are merged at different points along the path from the relevant peers to the query initializer (or namely, customer). However, query routing in P2P-IR networks is considered as one of the major challenges and critical part in P2P-IR networks; as the relevant peers might be lost in low-quality peer selection while executing the query routing, and inevitably lead to less effective retrieval results. This motivates this thesis to study and propose query routing techniques to improve retrieval quality in such networks. Cluster-based semi-structured P2P-IR networks exploit the cluster hypothesis to organise the peers into similar semantic clusters where each such semantic cluster is managed by super-peers. In this thesis, I construct three semi-structured P2P-IR models and examine their retrieval effectiveness. I also leverage the cluster centroids at the super-peer level as content representations gathered from cooperative peers to propose a query routing approach called Inverted PeerCluster Index (IPI) that simulates the conventional inverted index of the centralised corpus to organise the statistics of peers’ terms. The results show a competitive retrieval quality in comparison to baseline approaches. Furthermore, I study the applicability of using the conventional Information Retrieval models as peer selection approaches where each peer can be considered as a big document of documents. The experimental evaluation shows comparative and significant results and explains that document retrieval methods are very effective for peer selection that brings back the analogy between documents and peers. Additionally, Learning to Rank (LtR) algorithms are exploited to build a learned classifier for peer ranking at the super-peer level. The experiments show significant results with state-of-the-art resource selection methods and competitive results to corresponding classification-based approaches. Finally, I propose reputation-based query routing approaches that exploit the idea of providing feedback on a specific item in the social community networks and manage it for future decision-making. The system monitors users’ behaviours when they click or download documents from the final ranked list as implicit feedback and mines the given information to build a reputation-based data structure. The data structure is used to score peers and then rank them for query routing. I conduct a set of experiments to cover various scenarios including noisy feedback information (i.e, providing positive feedback on non-relevant documents) to examine the robustness of reputation-based approaches. The empirical evaluation shows significant results in almost all measurement metrics with approximate improvement more than 56% compared to baseline approaches. Thus, based on the results, if one were to choose one technique, reputation-based approaches are clearly the natural choices which also can be deployed on any P2P network.

HACIA UNA GEOGRAFÍA DE REDES: UN NUEVO PARADIGMA DE ANÁLISIS ESPACIAL ALTERNATIVO AL ENFOQUE REGIONAL

En este artículo se pretende rescatar el análisis de redes independientemente del enfoque aureolar, destacando sus virtudes en un mundo globalizado, en donde cada vez más el concepto de distancia es sustituido por de tiempo, hasta llegar al extremo de que el costo, de algunos productos o la información, ya no depende de la distancia como el caso de las tarifas planas de Internet. Se aborda un enfoque teórico metodológico que cuestiona  el  análisis  regional,  debido  a  que,  éste  enfoque  en  algunos  aspectos  ya  no puede  resolver  los  problemas  que  la  sociedad  actual  demanda.   En  el  espacio  red,la noción de  localización absoluta pierde vigencia, mientras se refuerza  la  importancia de la  conexión  a  las  redes. Las metodologías  propuestas,  podrían mejorar  la  ejecución  y operación  de  las  redes    presentes  en  los planes  de  ordenamiento  del  territorio,  tan  en boga, en nuestro país. Abstract:In  this article  it  is  tried  to rescue  the analysis of networks  independently of the approach  to  aureole, emphasizing  its  virtues  in a globalized world,  in where more and more the distance concept is replaced by the time, until arriving at the end of which the cost, no  longer depends on  the distance as  the case of  the  flat  tariffs of Internet. A theoretical/ methodological approach  that questions  the regional analysis, because,  this one approach  in some aspects no longer can solve the problems that the present society demand.  In  the  space  network,  the  notion  of  absolute  location  loses  use  while  the importance  of  the  connection  to  the  networks  is  reinforced.  The  proposed methodologies  could  improve  the  boarding  of  the  present  networks  in  the  regulating plans, so in rows, our country.

Tensor-Train decomposition for image classification problems

In these last years a great effort has been put in the development of new techniques for automatic object classification, also due to the consequences in many applications such as medical imaging or driverless cars. To this end, several mathematical models have been developed from logistic regression to neural networks. A crucial aspect of these so called classification algorithms is the use of algebraic tools to represent and approximate the input data. In this thesis, we examine two different models for image classification based on a particular tensor decomposition named Tensor-Train (TT) decomposition. The use of tensor approaches preserves the multidimensional structure of the data and the neighboring relations among pixels. Furthermore the Tensor-Train, differently from other tensor decompositions, does not suffer from the curse of dimensionality making it an extremely powerful strategy when dealing with high-dimensional data. It also allows data compression when combined with truncation strategies that reduce memory requirements without spoiling classification performance. The first model we propose is based on a direct decomposition of the database by means of the TT decomposition to find basis vectors used to classify a new object. The second model is a tensor dictionary learning model, based on the TT decomposition where the terms of the decomposition are estimated using a proximal alternating linearized minimization algorithm with a spectral stepsize.

Tree-based message diffusion for managing replicated data in unreliable and resource-constrained peer-to-peer environment

Abstract This thesis proposes a set of adaptive broadcast solutions and an adaptive data replication solution to support the deployment of P2P applications. P2P applications are an emerging type of distributed applications that are running on top of P2P networks. Typical P2P applications are video streaming, file sharing, etc. While interesting because they are fully distributed, P2P applications suffer from several deployment problems, due to the nature of the environment on which they perform. Indeed, defining an application on top of a P2P network often means defining an application where peers contribute resources in exchange for their ability to use the P2P application. For example, in P2P file sharing application, while the user is downloading some file, the P2P application is in parallel serving that file to other users. Such peers could have limited hardware resources, e.g., CPU, bandwidth and memory or the end-user could decide to limit the resources it dedicates to the P2P application a priori. In addition, a P2P network is typically emerged into an unreliable environment, where communication links and processes are subject to message losses and crashes, respectively. To support P2P applications, this thesis proposes a set of services that address some underlying constraints related to the nature of P2P networks. The proposed services include a set of adaptive broadcast solutions and an adaptive data replication solution that can be used as the basis of several P2P applications. Our data replication solution permits to increase availability and to reduce the communication overhead. The broadcast solutions aim, at providing a communication substrate encapsulating one of the key communication paradigms used by P2P applications: broadcast. Our broadcast solutions typically aim at offering reliability and scalability to some upper layer, be it an end-to-end P2P application or another system-level layer, such as a data replication layer. Our contributions are organized in a protocol stack made of three layers. In each layer, we propose a set of adaptive protocols that address specific constraints imposed by the environment. Each protocol is evaluated through a set of simulations. The adaptiveness aspect of our solutions relies on the fact that they take into account the constraints of the underlying system in a proactive manner. To model these constraints, we define an environment approximation algorithm allowing us to obtain an approximated view about the system or part of it. This approximated view includes the topology and the components reliability expressed in probabilistic terms. To adapt to the underlying system constraints, the proposed broadcast solutions route messages through tree overlays permitting to maximize the broadcast reliability. Here, the broadcast reliability is expressed as a function of the selected paths reliability and of the use of available resources. These resources are modeled in terms of quotas of messages translating the receiving and sending capacities at each node. To allow a deployment in a large-scale system, we take into account the available memory at processes by limiting the view they have to maintain about the system. Using this partial view, we propose three scalable broadcast algorithms, which are based on a propagation overlay that tends to the global tree overlay and adapts to some constraints of the underlying system. At a higher level, this thesis also proposes a data replication solution that is adaptive both in terms of replica placement and in terms of request routing. At the routing level, this solution takes the unreliability of the environment into account, in order to maximize reliable delivery of requests. At the replica placement level, the dynamically changing origin and frequency of read/write requests are analyzed, in order to define a set of replica that minimizes communication cost.

Organisational adaptation of multi-agent systems in a peer-to-peer scenario

Organisations in Multi-Agent Systems (MAS) have proven to be successful in regulating agent societies. Nevertheless, changes in agents' behaviour or in the dynamics of the environment may lead to a poor fulfilment of the system's purposes, and so the entire organisation needs to be adapted. In this paper we focus on endowing the organisation with adaptation capabilities, instead of expecting agents to be capable of adapting the organisation by themselves. We regard this organisational adaptation as an assisting service provided by what we call the Assistance Layer. Our generic Two Level Assisted MAS Architecture (2-LAMA) incorporates such a layer. We empirically evaluate this approach by means of an agent-based simulator we have developed for the P2P sharing network domain. This simulator implements 2-LAMA architecture and supports the comparison between different adaptation methods, as well as, with the standard BitTorrent protocol. In particular, we present two alternatives to perform norm adaptation and one method to adapt agents'relationships. The results show improved performance and demonstrate that the cost of introducing an additional layer in charge of the system's adaptation is lower than its benefits.

Transparent Network Interfaces to Mobile Peer-to-Peer Environment

The fact that most of new Personal Data Assistant (PDA) devices and smartphones have the ability to communicate via different wireless technologies has made several new applications possible. While traditional network model is based on the idea of static hosts, mobile devices can create decentralized, self-organizing ad-hoc networks and act as peers in the network. This kind of adapting network is suitable for mobile devices which can freely join and leave the networks. Because several different wireless communication technologies are involved, flexible changing of the networking technology must be handled in order to enable seamless communication between these networks. This thesis presents a transparent network interface to mobile Peer-to-Peer environment which is named as Virtual PeerHood. Different wireless technologies and aspects of providing a seamless connectivity between these technologies are explored. The result is a middleware platform for mobile Peer-to-Peer environment, capable of handling several networking technologies.

Design and Implementation of Peer-to-Peer Network over Bluetooth

During the last half decade the popularity of different peer-to-peer applications has grown tremendously. Traditionally only desktop-class computers with fixed line network connections have been powerful enough to utilize peer-to-peer. However, the situation is about to change. The rapid development of wireless terminals will soon enable peer-to-peer applications on these devices as well as on desktops. Possibilities are further enhanced by the upcoming high-bandwidth cellular networks. In this thesis the applicability and implementation alternatives of an existing peer-to-peer system are researched for two target platforms: Linux powered iPaq and Symbian OS based smartphone. The result is a peer-to-peer middleware component suitable for mobile terminals. It works on both platforms and utilizes Bluetooth networking technology. The implemented software platforms are compatible with each other and support for additional network technologies can be added with a minimal effort.

Design and implementation of a peer-to-peer client for device management

The aim of this master’s thesis was to specify a system requiring minimal configuration and providing maximal connectivity in the vein of Skype but for device management purposes. As peer-to-peer applications are pervasive and especially as Skype is known to provide this functionality, the research was focused on these technologies. The resulting specification was a hybrid of a tiered hierarchical network structure and a Kademlia based DHT. A prototype was produced as a proof-of-concept for the hierarchical topology, demonstrating that the specification was feasible.

Design and implementation of an anonymous peer-to-peer iaas cloud

Cloud services are becoming ever more important for everyone's life. Cloud storage? Web mails? Yes, we don't need to be working in big IT companies to be surrounded by cloud services. Another thing that's growing in importance, or at least that should be considered ever more important, is the concept of privacy. The more we rely on services of which we know close to nothing about, the more we should be worried about our privacy. In this work, I will analyze a prototype software based on a peer to peer architecture for the offering of cloud services, to see if it's possible to make it completely anonymous, meaning that not only the users using it will be anonymous, but also the Peers composing it will not know the real identity of each others. To make it possible, I will make use of anonymizing networks like Tor. I will start by studying the state of art of Cloud Computing, by looking at some real example, followed by analyzing the architecture of the prototype, trying to expose the differences between its distributed nature and the somehow centralized solutions offered by the famous vendors. After that, I will get as deep as possible into the working principle of the anonymizing networks, because they are not something that can just be 'applied' mindlessly. Some de-anonymizing techniques are very subtle so things must be studied carefully. I will then implement the required changes, and test the new anonymized prototype to see how its performances differ from those of the standard one. The prototype will be run on many machines, orchestrated by a tester script that will automatically start, stop and do all the required API calls. As to where to find all these machines, I will make use of Amazon EC2 cloud services and their on-demand instances.