Luis Fernando Ramos Molinaro

On survivability of IEEE 802.11 WLAN

In this paper, we address the problem of enhancing the survivability of IEEE 802.11 wireless local area networks focusing on tolerating access point-AP failures. We develop a simple fault detection approach, based on response timeout, which promises to be more cost-effective to identify failures due to lack of energy to an AP or problems with the wired link to an AP. In particular, we focus on the problem of overcoming these APs failures working with reconfiguration of the remaining APs by changing parameters such as power level and frequency channels. Our approach consists of two main phases: design and fault response. In design phase, we deal with quantifying, placement and setting up of APs according to both area coverage and performance criteria. In fault response phase we consider the reconfiguration of active APs in order to deal with AP fault in the service area. Finally, describe one of the major characteristics of the proposed system, which is a simple implementation in concordance with established IEEE 802.11 standards and related management systems

Ontology: An Analysis of the Literature

This work features a literature review about the ontology. From a study of literature are identified the types, methodologies, tools and languages used in the development of ontological tools. The result is an overview of the literature with definitions about ontologies in the area of computational systems, and the perception of researchers about the problems concerning the activity of creating and use of ontological tools. It is noticed that applications involving ontologies are significantly to academic conceptual and to create prototypes .

Enterprise Architecture to IT Governance: An Approach Based on Component Business Model and Performance Levels

The aim of this paper is to present an approach for a model that supports IT governance and management through the alignment of business with Information Technology – IT using Enterprise Architecture concepts, considering efficiency, effectiveness and security. Firstly, a theoretical review will be done emphasizing the assumptions that support IBM‘s Component Business Model, such as specialization, governance and strategy. Then, an approach is presented for the organization’s decomposition, considering IT and business alignment. Moreover, the performance levels concept is introduced to the CBM®. Finally, a governance and management model for components to be applied in case study is presented.

Fault tolerance in IEEE 802.11 WLANs

in this paper, we address the problem of enhancing the fault tolerance of IEEE 802.11 wireless local area networks focusing on tolerating access point - AP failures. We develop a fault detection approach, which promises to be more effective to identify AP failures. In particular, we focus on the problem of overcoming APs failures working with reconfiguration of the remaining APs by changing parameters such as power level and frequency channels. Our approach consists of two main phases: Design and Fault Response. In Design phase, we deal with quantifying, placement and setting up of APs according to both area coverage and performance criteria. In Fault Response phase we consider the reconfiguration of active APs in order to deal with AP fault in the service area. Finally, we describe one of the major characteristics of the proposed architecture, which is a simple implementation in concordance with established IEEE 802.11 standards and related management systems.

Analysis of the perturbation's size and the feeding topology on the dual-mode resonator in microstrip structure using FDTD

The dual-mode resonators have characteristics that make them highly attractive for use in wireless and mobile communications systems. In this work, the method of the finite differences time domain (FDTD) is used to analyze the behavior of the structure type according to the variation of the perturbations size and to the kind of the topology feeding.

Survivable mechanism for IEEE 802.11 WLAN improvements

In this paper we propose a mechanism to improve survivability in IEEE 802.11 WLAN. Our approach consists of two main phases: Design and Fault Response. In Design phase, we deal with quantifying, placement and setting up of APs according to both area coverage and performance criteria. In Fault Response phase we consider the reconfiguration of active APs in order to deal with AP fault in the service area. We analyze changes in both power level and frequency channel assignment of the remaining APs, searching for the best configuration during the fault condition. We also propose area coverage and performance metrics to evaluate the effectiveness of the solution for the fault condition, according to the fault tolerance constrains de-fined in the Design phase. Finally, we present an implementation of the proposed techniques.

A formulação de estratégias organizacionais com base na mudança do modelo de negócio: Apontamentos sobre o contexto comunicacional

O presente trabalho tem como objetivo apresentar os conceitos relacionados a modelo de negocios com foco na analise de grupos de comunicacao. Aborda, do ponto de vista da convergencia tecnologica e do desenvolvimento das tecnologias da informacao e comunicacao, as alteracoes estruturais e questoes relacionadas a migracao de valor e a mudanca no modelo de negocios dos referidos grupos. A metodologia centra-se em um estudo exploratorio com foco nos significados dessas mudancas para o mercado, para o consumidor do jornal impresso e on-line e seus stakeholders.