1,375 research outputs found
Using PTES and open-source tools as a way to conduct external footprinting security assessments for intelligence gathering
The first phase in a security assessment activity (legitimate or not) consists in the information gathering procedures that need to be conducted about a specific target. Information gathering, also known as footprinting, is the process of collecting all available and accessible information about a specific target to assess. While conducting a security assessment, this is one of the most important stages and usually involves the examination, collection and classification of large volumes of data from the target. The Penetration Testing Execution Standard (PTES), provides the description of the processes that are necessary to conduct penetration-testing assessments in a generic and integrated manner in all the different stages that compose such penetration testing process. However, the particular focus of this article consists in the analysis of the standard and its recommendations on what concerns footprinting processes and how to provide some contributions in terms of the practical applicability, namely on the usage of open-source footprinting applications, in the implementation of PTES recommendations.info:eu-repo/semantics/publishedVersio
A Influência da espessura cortical na avaliação da resistência femoral
O comportamento biomecânico do osso e a avaliação da sua resistência dependem
das caracterÃsticas estruturais e geométricas da espessura cortical [1]. De acordo com
estudos efectuados, a fractura do colo do fémur pode ocorrer no osso cortical sob efeito
de esforços à tracção [2, 3]. Para além disso, a espessura do osso cortical não é uniforme
e varia de acordo com a idade do indivÃduo. É objectivo deste trabalho verificar a
influência da variação da espessura cortical na resistência biomecânica de modelos de
diferentes fémures.
Recorrendo ao tratamento e estudo de imagens médicas, obtidas por tomografia
computorizada, torna-se possÃvel a utilização de técnicas avançadas de engenharia para
a medição e a determinação da espessura cortical em diferentes modelos anatómicos.
Essa avaliação pode ser efectuada com recurso a programas de tratamento de imagem e
a técnicas de processamento para a obtenção de modelos protótipos. Estas duas técnicas
permitirão registar valores da espessura cortical em diferentes zonas anatómicas nos
modelos em estudo.
A avaliação da resistência femoral será efectuada com o recurso à técnica de elementos
finitos, onde cada modelo em estudo será analisado para condições de carregamento
idênticas.
A metodologia proposta neste trabalho permitirá aferir as zonas mais susceptÃveis à falha
mecânica nos diferentes modelos de fémures, verificando em simultâneo a influência
da espessura do osso cortical medida. O estudo proposto incide na análise de quatro
imagens médicas de fémures do género feminino com idades próximas (40, 41, 52 e
53 anos)
A fatal case by a suicide kit containing sodium nitrite ordered on the internet
Fatal sodium nitrite poisonings are rare in the forensic context. The present work describes a first fatal case of sodium nitrite contained in a suicide kit that the victim acquired over the internet. The results of the autopsy showed general signs of asphyxia, such as intense cyanosis of the extremities, brown-gray-blue-red livor mortis, and some Tardieu petechiae in addition to intense visceral congestion. It is clear that forensic experts must be aware of the proliferation of this market and the risks of improper selling of these substances through suicide support networks available on the internet. The lack of knowledge of this reality may become unidentifiable, when toxicological analysis contemplates only the most classical and frequent substances involved in poisoning and reinforce the importance of a careful analysis of the death scene.info:eu-repo/semantics/publishedVersio
Performance bound for generalized M-QAM constellations in time-discrete multipath rayleigh fading channels with channel estimation errors
In this paper we derive a lower bound on the bit error rate (BER) for the individual bit streams that can be mapped simultaneously in an hierarchical way onto generalized multilevel quadrature amplitude modulations (M-QAM). The expressions are valid for time-discrete multipath Rayleigh fading environments with imperfect channel estimation and can be regarded as an extension of the well-known matched filter bound (MFB).info:eu-repo/semantics/acceptedVersio
Joint detection and channel estimation for MIMO systems with SC-FDE modulations
SC modulation (Single-Carrier) with FDE (Frequency-Domain Equalization) allows excellent performance in severely time-dispersive channels, provided that accurate channel estimates are available at the receiver. For this purpose, pilot symbols and/or training sequences are usually multiplexed with data symbols, which lead to spectral degradation. As an alternative, we can use implicit pilots (i.e., pilots superimposed to data). In this paper we consider MIMO SC-FDE systems where the channel estimation is based on either explicit or implicit pilots, for comparison purposes. An iterative receiver with joint equalization, turbo decoding and channel estimation was employed for optimum results, and to reduce the high interference levels between data and pilots (for the implicit pilots). The main differences between the different schemes are discussed and the performance results show that the use of the proposed techniques for channel estimation yield excellent results.info:eu-repo/semantics/acceptedVersio
Emergencies after endoscopic procedures
Endoscopy adverse events (AEs), or complications, are a rising concern on the quality of endoscopic care, given the technical advances and the crescent complexity of therapeutic procedures, over the entire gastrointestinal and bilio-pancreatic tract. In a small percentage, not established, there can be real emergency conditions, as perforation, severe bleeding, embolization or infection. Distinct variables interfere in its occurrence, although, the awareness of the operator for their potential, early recognition, and local organized facilities for immediate handling, makes all the difference in the subsequent outcome. This review outlines general AEs' frequencies, important predisposing factors and putative prophylactic measures for specific procedures (from conventional endoscopy to endoscopic cholangio-pancreatography and ultrasonography), with comprehensive approaches to the management of emergent bleeding and perforation
Iterative decoding and channel estimation of MIMO-OFDM transmissions with hierarchical constellations and implicit pilots
In this paper we consider the use of M-QAM hierarchical constellations (Quadrature Amplitude Modulation) combined with implicit pilots for the transmission of multicast and broadcast services in a MIMO-OFDM (Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing) system. This method of pilot transmission allows coherent detection at the receiver while avoiding the spectral degradation associated with the usual pilot multiplexing techniques but results in mutual interference between pilots and data. Due to the demanding channel estimation requirements and the high sensitivity to interference resulting from the usage of several antennas and hierarchical constellations, an enhanced receiver based on the turbo concept is developed which is capable of dealing with the inherent interference between pilots and data.info:eu-repo/semantics/acceptedVersio
Response.
Response:
LuÃs Lopes, MD, PhD
Mário Dinis-Ribeiro, MD, PhD
Carla Rolanda, MD, PhD
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doi:10.1016/j.gie.2015.01.001
Refers To:
Panagiotis Katsinelos, Georgia Lazaraki, Grigoris Chatzimavroudis, Christos Zavos, Jannis Kountouras
The endoscopic morphology of major papillae influences the selected precut technique for biliary access
Gastrointestinal Endoscopy, Volume 81, Issue 4, April 2015, Page 105
Efficient channel estimation for OFDM systems with hierarchical constellations
In this paper we consider the use of M-QAM hierarchical constellations (Quadrature Amplitude Modulation) combined with implicit pilots for the transmission of multicast and broadcast services in OFDM (Orthogonal Frequency Division Multiplexing) systems. This method of pilot transmission allows coherent detection at the receiver while avoiding the spectral degradation associated with the usual pilot multiplexing techniques but results in mutual interference between pilots and data. Due to the demanding channel estimation requirements and the high sensitivity to interference resulting from the usage of QAM hierarchical constellations, an enhanced receiver based on the turbo concept is developed which is capable of dealing with the inherent interference between pilots and data.info:eu-repo/semantics/acceptedVersio
Permanent deformation characterization of bituminous mixtures: laboratorial tests
In the last years some laboratorial tests are used to predict the permanent deformation behaviour of
bituminous mixtures. Among those tests the Wheel Tracking test, the Cyclic Compression Test (Uniaxial and
Triaxial) and the Repetitive Shear at Constant Height (RSCH) test, are considered for Portuguese practice. Also
come out recently new European standards for those tests, with exception of the RSCH which is essentially used
in the USA. Nevertheless some of testing conditions are not very well defined. Therefore, it is important to study
the reliability and accuracy of each test in the task of predicting permanent deformation behaviour. In this work
these test were used in the evaluation of a commonly used mixture in Portugal. Results show that all tests are
suitable for predicting permanent deformation behaviour. Thus simpler and cheaper tests are more interesting to
use.(undefined
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