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- Architecture to integrate broadband access networks and wireless gridsPublication . Pereira, João PauloToday, the access networks face two main challenges: the increasing bandwidth demand and mobility trends. All this will require fundamental changes to the operations of access networks, the functionality of network nodes and the architecture itself. By other side, the evolution of computing and communication networks toward decentralized and distributed systems implies that all the intelligence is on the edge nodes of the networks. Integrating wireless devices with the traditional wired grid infrastructure will allow the access (transfer, processing, etc) to the information that is now scattered across the different devices. In this paper, we present a new architecture and a cost model to support the new requirements of broadband access (fixed and nomadic users) and wireless grids in an integrated way.
- Next generation access networks (NGANs) and the geographical segmentation of marketsPublication . Pereira, João Paulo; Ferreira, Pedro A.Telecom infrastructures are facing unprecedented challenges with increasing demands on network capacity. Next Generation Networks (NGN) allows consumers to choose between different access network technologies to access their service environment. The arrival of NGAN (Next Generation Access Network) has implications for the competitive conditions in access markets that are still uncertain (for example: access to ducts, dark fiber, equipment, etc.). The definition of the access price is a critical question, particularly when the incumbent also has activity in the retail market. In some regions, the regulatory authorities need to define the max price for wholesale access. In this context, the paper is divided into two main parts: 1) First we make a review of the main broadband access technologies (NGANs), and we propose a techno-economic model to support the new requirements of fixed and nomadic users. 2) In the 2nd part we propose a tool, developed in c language, which simulates the impact of retail and wholesale services prices variation in the provider’s profit, consumer surplus, welfare, etc.
- Model to evaluate the maturity of the organizational structure: a new approachPublication . Pereira, João Paulo; Grubich, TatianaThe concept of maturity is quite multifaceted and is applied in various areas of activity of the modern society. Most often, the concept of maturity is applied to the information technologies of the enterprise and to the processes of software development. The maturity level models used do not give the concept of maturity of the organizational structure and do not allow to assess the maturity of the organizational structure. Through existing models, it is possible to assess the quality of IT projects and processes for their implementation. In this paper, we propose a new approach to evaluate the maturity level of the organizational structure of an enterprise. With the proposed criteria, it is possible to analyze the way that the organizational structure of an enterprise meets its objectives. We also propose methods for formalizing the information obtained in the analysis of the organizational structure of the enterprise, which is used to calculate the criteria for the level of maturity of the organizational structure. Based on the results computed, a scale is proposed for determining the level of maturity of the organizational structure of the enterprise.
- Estudo comparativo entre os modelos de redes neuronais artificiais e regressão linear múltipla na modelação e previsão da procura turística em MoçambiquePublication . Constantino, Hortêncio; Fernandes, Paula Odete; Pereira, João PauloO principal objetivo do presente trabalho assenta no estudo comparativo entre Redes Neuronais Artificiais e o modelo de Regressão Linear Múltipla, para prever a procura turística em Moçambique. Utilizou-se para tal, o número de dormidas mensais registadas nos estabelecimentos hoteleiros, para o período de Janeiro de 2004 a Dezembro de 2013 como variável dependente. Neste contexto foram selecionadas as variáveis explicativas: Índice Harmonizado de Preços ao Consumidor, Produto Interno Bruto e Taxa de Câmbio para os principais mercados emissores: África Sul, Estados Unidos da América, Moçambique, Portugal e Reino Unido. O modelo de redes neuronais artificiais tem uma arquitetura feedforward com uma camada escondida. Experimentaram-se diversas combinações das variáveis de entrada, diferente número de nós na camada escondida, e diferentes funções de ativação. Experimentaram-se ainda diferentes formas de apresentar a variável dependente, nomeadamente na sua forma natural (o seu valor absoluto), na forma exponencial e na forma de diferenças logarítmicas. Das diversas experiências apresentam-se aqui as melhores soluções. Destacam-se, com melhores resultados, a utilização das variáveis de entrada: índice de preços ao consumidor de Moçambique, e as taxas de câmbio do euro, do rand e do dólar face ao metical. Em alguns casos as variáveis do produto interno bruto dos Estados Unidos da América e de Portugal adicionalmente às anteriores melhoram as previsões. A partir dos resultados obtidos pôde-se observar que o modelo de Redes Neuronais Artificias produziu melhores previsões, ou seja, apresentou uma qualidade estatística de ajuste bastante satisfatória. Assim, o mesmo permitiu efetuar previsões para a procura turística em Moçambique, apresentando um coeficiente de correlação de Pearson de 0,696 e um Erro Percentual Absoluto Médio (MAPE) de 6,5%, num conjunto de teste nunca visto no processo de ajuste/treino do modelo.
- De que forma as redes sociais podem ser utilizadas na criação de conhecimentoPublication . Lopes, Isabel Maria; Pereira, João PauloA facilidade com que hoje em dia os estudantes têm em aceder à Internet e às redes sociais, e com a sua desmedida proliferação, é oportuno saber até que ponto não são meros mecanismos de diversão, mas sim, grandes fontes de informação e conhecimento. Este artigo pretende contribuir para o melhor entendimento desta problemática. Apresentando um trabalho que vá para além da revisão da literatura, através da apresentação de um estudo empírico que revele a relação entre as redes sociais e a obtenção de conhecimento em alunos do ensino superior. Com vista à realização deste estudo, entendeu-se apropriado aplicar a técnica de questionário, uma vez que potencia uma resposta clara, direta e objetiva. Além disso, uma vez que visa a análise de uma população estudantil, constituída por 290 estudantes do ensino superior, julga-se ser o método de investigação mais apropriado. Os resultados são discutidos á luz dos dados recolhidos no questionário e identificados trabalhos futuros.
- SimEmp: a game simulation in management teachingPublication . Alves, Jorge; Soares, Ricardo; Moutinho, Nuno; Pereira, João PauloA utilização de novas metodologias de ensino que acompanhem o desenvolvimento da sociedade e das tecnologias de informação e comunicação podem ser uma poderosa ferramenta no ensino da gestão. Neste trabalho é apresentado o Simulador Empresarial (SimEmp) que torna a aprendizagem mais fácil na obtenção de competências na área das ciências empresariais e, sob a forma de um jogo, permite simular o contexto real em que as empresas se inserem. Com a simulação os alunos obtêm conhecimentos e competências úteis para a sua formação, tendo a mesma potencial para melhorar a capacidade de os alunos reterem as aprendizagens.
- Evaluation of information systems curriculum in Portugal and RussiaPublication . Pereira, João Paulo; Aleksandr, Ivlev; Popova, ElenaThe importance of Information Technology (IT) and Information Systems (IS) to organizations and the need for skilled professionals in the field is one of the most important challenges to universities. With the technological and organizational changes, IS education has been under continued adaptation, and higher education institutions have several difficulties in keeping the bachelor degrees curriculum updated. Several international organizations (ACM, AIS, BCS, IFIP, etc.) proposed for the last 40 years several curriculum guidelines, which are important to redesign the curriculum for survival in the current economic environment. The main purpose of this work is to compare Portuguese and Russian bachelor degrees with several standard curriculum on Information Systems proposed by recognized international organizations. The results obtained show the differences that exist between international curriculum guidelines and the bachelor degrees, and give us a perspective of the adequacy of the Portuguese and Russian curricula to the current requirements.
- A demonstration of an application of the bertrand network: guessing the distribution of buyers within the marketPublication . Ferreira, Murillo Henrique Pedroso; Pereira, João PauloBertrand and the Cournot model are one of the most used model for modeling competition between companies. This paper presents a work-in-progress that studies the application of the recently developed Bertrand Network model by using it in a reverse manner: first it is considered that firms are competing in equilibrium, then, after analyzing how companies are choosing prices, it is calculated which distribution of buyers would lead to that equilibrium. An unreal example is presented to help to understand the model. Furthermore, a formula is suggested to expand the networked model to allow a mix of duopolies and oligopolies
- Development of an effective method of tariff formation for rural areas: the case of Russian FederationPublication . Pereira, João Paulo; Zamotajlova, Daria; Popova, ElenaThe conducted researches have shown that the features of the housing and communal sector do not allow talking about the possibility of calculating the “optimal” tariff rate. Also in the current conditions in Russia, tariff methods that are successfully used abroad (for example, the method of reinvested capital) cannot be used. The correct approach to housing and communal tariff formation is the calculation of compromise tariffs, the size of which takes into account the interests of consumers of services, resource-supply organizations, public authorities and investors. Development of an effective method of tariff formation for rural areas is particularly acute. The correct approach to housing and communal tariff formation is the calculation of compromise tariffs, the size of which takes into account the interests of services’ consumers, resource-supply organizations, public authorities and investors. Compromise approach for tariffs’ formation can also become an effective instrument not only in Russia: it can be applied in countries where it is sufficient to calculate housing and communal services’ social demand and its budget coverage (e.g. because of the increasing number of migrants).
- Infrastructure vs. access competition in NGNsPublication . Pereira, João PauloWith the introduction of NGNs, operators need to upgrade their access networks because in several cases, existing access networks can no longer meet increasing customer expectations. Evolving consumer expectations will require changes to the existing access network – next generation access. However, existing technologies faces some difficulties and are not ready for large-scale roll-out yet. For example, in the case of DSL technologies, the great majority of operators with copper networks are improving their networks, making investments to deploy fiber optics closer to customers and offering higher-speed access, which is required for new emerging services (reducing the distance between fiber and the users.). The entry of new competitors can be based on the resale of services from the incumbent, on building up their own infrastructures, on renting unbundled infrastructure from incumbents, or, on the combination of the above elements. Then, is important create the right incentive for operators to make an efficient build/buy choice and define the appropriate pricing principles.
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