História, memória e espaços: experiências dos ex-combatentes de Parelhas-RN na defesa do litoral brasileiro durante a Segunda Guerra Mundial

The present essay has how I aim to analyse the memories of the ex-combatants of Parelhas-RN, specially of the components of the Força de Vigilância e Segurança do Litoral - FVSL, protagonists of the Brazilian participation in the scenery of the Second World war. Along this we looked to understand in which surrounding geographicalpartner these men were living before the War and what were the consequences of a brusque change of space owing to the convocation for the Armed Brazilian Strength in that historical context. The defense of the Brazilian coast during the War was not a so simple task, I have in mind the precariedade logistics of the Armed Strength, the attacks of submarines of the Axle that killed hundreds of civilians and Brazilian soldiers and the net of espionage mounted by Germany in Brazil. Leaving from the notion of collective memory and estrangement in Maurice Halbwachs, we will use the oral history like principal methodology, with the end of rescue these underground memories what also will make possible us the vision realizes that the protagonists themselves have of the event, besides the use of documents, photos, maps and any sort of fountains that make possible us to rebuild the scenery of Parelhas in the beginning of the War and the trajectory of life of his veterans

Indicador de inconformidades em instalações elétricas de baixa tensão

With the progress of devices technology, generation and use of energy ways, power quality parameters start to influence more significantly the various kinds of power consumers. Currently, there are many types of devices that analyze power quality. However, there is a need to create devices, and perform measurements and calculate parameters, find flaws, suggest changes, and to support the management of the installation. In addition, you must ensure that such devices are accessible. To maintain this balance, one magnitude measuring method should be used which does not require great resources processing or memory. The work shows that application of the Goertzel algorithm, compared with the commonly used FFT allows measurements to be made using much less hardware resources, available memory space to implement management functions. The first point of the work is the research of troubles that are more common for low voltage consumers. Then we propose the functional diagram indicate what will be measured, calculated, what problems will be detected and that solutions can be found. Through the Goertzel algorithm simulation using Scilab, is possible to calculate frequency components of a distorted signal with satisfactory results. Finally, the prototype is assembled and tests are carried out by adjusting the parameters necessary for one to maintain a reliable device without increasing its cost.

Estudo e desenvolvimento de algoritmos criptográficos para redes de sensores sem fio, utilizando técnicas de programação genética

Cryptography is the main form to obtain security in any network. Even in networks with great energy consumption restrictions, processing and memory limitations, as the Wireless Sensors Networks (WSN), this is no different. Aiming to improve the cryptography performance, security and the lifetime of these networks, we propose a new cryptographic algorithm developed through the Genetic Programming (GP) techniques. For the development of the cryptographic algorithm’s fitness criteria, established by the genetic GP, nine new cryptographic algorithms were tested: AES, Blowfish, DES, RC6, Skipjack, Twofish, T-DES, XTEA and XXTEA. Starting from these tests, fitness functions was build taking into account the execution time, occupied memory space, maximum deviation, irregular deviation and correlation coefficient. After obtaining the genetic GP, the CRYSEED and CRYSEED2 was created, algorithms for the 8-bits devices, optimized for WSNs, i.e., with low complexity, few memory consumption and good security for sensing and instrumentation applications.

Estudo e desenvolvimento de algoritmos criptográficos para redes de sensores sem fio, utilizando técnicas de programação genética

Cryptography is the main form to obtain security in any network. Even in networks with great energy consumption restrictions, processing and memory limitations, as the Wireless Sensors Networks (WSN), this is no different. Aiming to improve the cryptography performance, security and the lifetime of these networks, we propose a new cryptographic algorithm developed through the Genetic Programming (GP) techniques. For the development of the cryptographic algorithm’s fitness criteria, established by the genetic GP, nine new cryptographic algorithms were tested: AES, Blowfish, DES, RC6, Skipjack, Twofish, T-DES, XTEA and XXTEA. Starting from these tests, fitness functions was build taking into account the execution time, occupied memory space, maximum deviation, irregular deviation and correlation coefficient. After obtaining the genetic GP, the CRYSEED and CRYSEED2 was created, algorithms for the 8-bits devices, optimized for WSNs, i.e., with low complexity, few memory consumption and good security for sensing and instrumentation applications.