Parallel Cyclostationarity-Exploiting Algorithm for Energy-Efficient Spectrum Sensing

The evolution of wireless communication systems leads to Dynamic Spectrum Allocation for Cognitive Radio, which requires reliable spectrum sensing techniques. Among the spectrum sensing methods proposed in the literature, those that exploit cyclostationary characteristics of radio signals are particularly suitable for communication environments with low signal-to-noise ratios, or with non-stationary noise. However, such methods have high computational complexity that directly raises the power consumption of devices which often have very stringent low-power requirements. We propose a strategy for cyclostationary spectrum sensing with reduced energy consumption. This strategy is based on the principle that p processors working at slower frequencies consume less power than a single processor for the same execution time. We devise a strict relation between the energy savings and common parallel system metrics. The results of simulations show that our strategy promises very significant savings in actual devices.

Parallel Cyclostationarity-Exploiting Algorithm for Energy-Efficient Spectrum Sensing

The evolution of wireless communication systems leads to Dynamic Spectrum Allocation for Cognitive Radio, which requires reliable spectrum sensing techniques. Among the spectrum sensing methods proposed in the literature, those that exploit cyclostationary characteristics of radio signals are particularly suitable for communication environments with low signal-to-noise ratios, or with non-stationary noise. However, such methods have high computational complexity that directly raises the power consumption of devices which often have very stringent low-power requirements. We propose a strategy for cyclostationary spectrum sensing with reduced energy consumption. This strategy is based on the principle that p processors working at slower frequencies consume less power than a single processor for the same execution time. We devise a strict relation between the energy savings and common parallel system metrics. The results of simulations show that our strategy promises very significant savings in actual devices.

PSEUDO: uma análise sociocognitiva sobre insinceridades, mentiras e crimes de fraude

The objective of this work is to analyze the phenomenon of lying, highlighting some uses and social consequences. Lies are a ubiquitous phenomenon, and in many cases they even promote social harmony. Furthermore, telling lies is an expression of individuality: it is the expression of relative autonomy that the subject has towards their social environment allowing them to defend their most personal interests. The work also aims to examine the concept of habitus applied to the social production of lies. Thus, the liars produce their lies aiming to obtain certain effects on their audiences. There are certain social cognitive principles that structure the kind of lie that is usually told to the public. Finally, the perpetrators of crimes of fraud and other deceptive practices may suffer a criminal prosecution because the damage they cause affects important social values recognized by the state, and are not restricted to the victim‟s chagrin. In the most common forms of fraud, the crooks make tempting offers to victims exploiting some of their standardized behaviors and reactions. To understand the fragility of the victims to scams is an attempt to understand how a social phenomenon as usual as is the lie can still surprise and cause perplexity

Educação ambiental: mediações sociais e políticas e a indolência do Poder Público à sua inclusão no ensino formal

As a result of the prediction of irreversible changes on necessary conditions to maintain life, including human, on the planet, environmental education got the spotlight in the political scenario, due to social pressure for the development of individual and collective values, knowledge, skills, attitudes and competences towards environmental preservation. In Brazil, only in 1999 the right for environmental education was officially granted to people, having the status of essential and permanent component in the country s education. Since then, it has been Government s duty, in each federal branch, to plan actions to make it happen, in an articulate way in all levels and modalities of the education process, both formally and informally. This work of research has environmental education in the school as subject matter, and aims on analyzing social and political mediations established between this National Environmental Education policy and the contexts associated to the legislative production process, the political nature of the conceptions about environmental education that underlie Law 9.795/99 (Brazil, 2009c) and also Rio Grande do Norte Government s actions and omissions related to the imperative nature of the insertion of environmental education in the schools ran by the state, during the ten years this law has been in force. The investigation of the subject matter was led by a social and historical understanding of the social and environmental phenomena, as well as of the education system as a whole, considering that only through a dialectical view we can see the real world, by destroying the pseudo-concreteness that surrounds the topic. While analyzing, we assumed that in face of the dominance of a social organization in which market regulations rule on environmental ones, by developing individual and collective critical conscience, environmental education can become a threat to dominant economical interests in exploiting natural resources. The results of this research suggest that as an educational practice to be developed in an integrated, continuous and permanent fashion in all levels and modalities of formal education, environmental education has not yet come to pass in the state of Rio Grande do Norte, due to the neglect and disrespect of the government when facing the need of promoting the necessary and legally appointed measures to make it present in the basic education provided by the state. The legislators silence when it comes to approving a regulation on environmental education essential to define policies, rules and criteria to teaching the subject in the state and the omission from the public administration regarding critical actions in order to integrate in public schools the activities related to the National Environmental Education Policy, represent a political decision for not doing anything, despite the legal demand for an active position. This neglecting attitude for the actualizing of strategically concrete actions, urgent and properly planned for the implementation of environmental education in schools in a multidisciplinary way, exposes the lack of interest the predominant classes have in such kind of education being made available, as it could be developed based on a critic political view, becoming a political and educational action against dominance. When analyzing the basic principles and fundamental goals in Law 9.795/99 (Brazil, 2009c) the development of a critic environmental education is really possible and concurs with the National Environmental Education Policy, reflecting the social and political mediations established between this public policy and the contexts associated to its legislative production process, which are responsible for approving a regulation which also represents the mind of the people about environmental protection above anything else

O Prêmio Nacional de Qualidade e as políticas e práticas de recursos humanos :um estudo em empresas do setor de transporte público por ônibus da região metropolitana de Natal/RN

This work has goal of analyzing the practices of Human Resources in the per missionary enterprises of urban transportation, by bus, in the metropolitan region of de Natal, based on the standard person of the National Program of Quality 2004 and points if they are able to take part as prize-winning in this standard. Also this work aims, through a theoretical evolution of people management and its current practices, the history of the National prize Quality and its main standards, the importance of the urban transportation, its characteristics and the system itself in the metropolitan region of Natal. The research was carried out in 11 enterprises that operated in the area, with several dimensions and forms of management. The research variations were based on the standard person of the 2004 NPQ that deals with the system of work, preparation and development and life quality. In the statistical treatment, discriminated and exploiting analyses were applied. The main obtained results through the research, we can verify an administrative centralization in managers and owners hands; that 45% of the enterprises don t have a Human Resources Department, however, on the other hand, they practice some human Resources politics, indicated by the variations; as to the items system of work, 55% of the enterprises are able; preparing and development, 43%

Calibração cega de receptores cinco-portas baseada em separação cega de fontes

The exponential growth in the applications of radio frequency (RF) is accompanied by great challenges as more efficient use of spectrum as in the design of new architectures for multi-standard receivers or software defined radio (SDR) . The key challenge in designing architecture of the software defined radio is the implementation of a wide-band receiver, reconfigurable, low cost, low power consumption, higher level of integration and flexibility. As a new solution of SDR design, a direct demodulator architecture, based on fiveport technology, or multi-port demodulator, has been proposed. However, the use of the five-port as a direct-conversion receiver requires an I/Q calibration (or regeneration) procedure in order to generate the in-phase (I) and quadrature (Q) components of the transmitted baseband signal. In this work, we propose to evaluate the performance of a blind calibration technique without additional knowledge about training or pilot sequences of the transmitted signal based on independent component analysis for the regeneration of I/Q five-port downconversion, by exploiting the information on the statistical properties of the three output signals

Contribuição para o estudo do embarque de uma rede neural artificial em field programmable gate array (FPGA)

This study shows the implementation and the embedding of an Artificial Neural Network (ANN) in hardware, or in a programmable device, as a field programmable gate array (FPGA). This work allowed the exploration of different implementations, described in VHDL, of multilayer perceptrons ANN. Due to the parallelism inherent to ANNs, there are disadvantages in software implementations due to the sequential nature of the Von Neumann architectures. As an alternative to this problem, there is a hardware implementation that allows to exploit all the parallelism implicit in this model. Currently, there is an increase in use of FPGAs as a platform to implement neural networks in hardware, exploiting the high processing power, low cost, ease of programming and ability to reconfigure the circuit, allowing the network to adapt to different applications. Given this context, the aim is to develop arrays of neural networks in hardware, a flexible architecture, in which it is possible to add or remove neurons, and mainly, modify the network topology, in order to enable a modular network of fixed-point arithmetic in a FPGA. Five synthesis of VHDL descriptions were produced: two for the neuron with one or two entrances, and three different architectures of ANN. The descriptions of the used architectures became very modular, easily allowing the increase or decrease of the number of neurons. As a result, some complete neural networks were implemented in FPGA, in fixed-point arithmetic, with a high-capacity parallel processing

CrossMDA-SPL: uma abordagem para gerência de variabilidades dirigida por modelos e aspectos

This paper proposes a systematic approach to management of variability modelsdriven and aspects using the mechanisms of approaches Aspect-Oriented Software Development (AOSD) and Model-Driven Development (MDD). The main goal of the approach, named CrossMDA-SPL, is to improve the management(gerência), modularization and isolation ou separation of the variability of the LPSs of architecture in a high level of abstraction (model) at the design and implementing phases of development Software Product Lines (SPLs), exploiting the synergy between AOSD and MDD. The CrossMDA-SPL approach defines some artifacts basis for advance the separation clear in between the mandatory (bounden) and optional features in the architecture of SPL. The artifacts are represented by two models named: (i) core model (base domain) - responsible for specify the common features the all members of the SPL, and (ii) variability model - responsible for represent the variables features of SPL. In addition, the CrossMDA-SPL approach is composed of: (i) guidelines for modeling and representation of variability, (ii) CrossMDA-SPL services and process, and (iii) models of the architecture of SPL or product instance of SPL. The guidelines use the advantages of AOSD and MDD to promote a better modularization of the variable features of the architecture of SPL during the creation of core and variability models of the approach. The services and sub-processes are responsible for combination automatically, through of process of transformation between the core and variability models, and the generation of new models that represent the implementation of the architecture of SPL or a instance model of SPL. Mechanisms for effective modularization of variability for architectures of SPL at model level. The concepts are described and measured with the execution of a case study of an SPL for management systems of transport electronic tickets