905 resultados para Advanced Encryption Standard
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Aim: To establish the histological categorization of fibrotic stroma which reflects the biological behaviour of advanced rectal cancer. Methods and results: Six hundred and twenty-seven surgically resected cases of advanced rectal carcinoma were examined. We histologically categorized fibrotic stroma in the invasive frontal region into three groups: type A, multiple fine and mature fibres were stratified into layers: type B, broad bands of eosinophilic hyalinized collagen ('keloid-like' collagen) were intermingled: type C, myxoid stroma. Type A stroma was observed in 63% of patients, type B stroma in 25%, type C stroma in 12%.. The incidence of type A stroma decreased in accordance with Dukes stage (98% in Dukes A: 73% in B: 41%, in C1: 29% in C2) and conversely, there was an increase of C type (0%, in Dukes A; 4%, in B: 20% in C1: 54% in C2). Stroma type had a significant correlation with long-term survival (80% of 5-year survival in type A stroma: 54% in type B: 26% in type C). Based on multivariate analysis. it was found that the stromal pattern had independent prognostic value, together with nodal involvement. growth pattern. and lymphocyte infiltration. Conclusions: Tumour fibrotic stroma may play an important role as a regulator of neoplastic behaviour. Pathological categorization of the fibrotic stroma is helpful for predicting the prognostic outcome of patients with rectal carcinoma.
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In the first part of this study, we characterized 24-month-old Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs), their heart weights, and the responses of the isolated left ventricles to electrical stimulation. In the main part of the study, we tested whether the positive inotropic effects of BDF 9198, which prevents the closure of the cardiac sodium channel, were present in senescence and heart failure. Thus, we studied the effects of BDF 9198 on the left ventricle strips of 24-month-old WKY rats (senescence) and SHRs using contractility methods. In comparison with WKY rats, the left ventricles of 24-month-old SHRs were hypertrophied and had prolonged times to peak contraction. BDF 9198 (10(-8) to 10(-6) m) was a positive inotrope on the left ventricles of WKY rats, with a maximum augmenting effect of 122% with BDF 9198 at 10(-7) m. The magnitude of the augmenting effects of BDF 9198 were reduced in SHR heart failure, with a maximum augmenting effect of 26% at 10(-7) m. BDF 9198 at 10(-6) m attenuated the responses of the SHR left ventricle to electrical stimulation. In conclusion, the potential of drugs that prevent closure of the sodium channel as positive inotropes in the treatment of heart failure should be further considered.
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Frequency deviation is a common problem for power system signal processing. Many power system measurements are carried out in a fixed sampling rate assuming the system operates in its nominal frequency (50 or 60 Hz). However, the actual frequency may deviate from the normal value from time to time due to various reasons such as disturbances and subsequent system transients. Measurement of signals based on a fixed sampling rate may introduce errors under such situations. In order to achieve high precision signal measurement appropriate algorithms need to be employed to reduce the impact from frequency deviation in the power system data acquisition process. This paper proposes an advanced algorithm to enhance Fourier transform for power system signal processing. The algorithm is able to effectively correct frequency deviation under fixed sampling rate. Accurate measurement of power system signals is essential for the secure and reliable operation of power systems. The algorithm is readily applicable to such occasions where signal processing is affected by frequency deviation. Both mathematical proof and numerical simulation are given in this paper to illustrate robustness and effectiveness of the proposed algorithm. Crown Copyright (C) 2003 Published by Elsevier Science B.V. All rights reserved.
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[GRAPHICS] Rapid access to the ABCE ring system of the C-20 diterpene alkaloids was achieved by silver(I)-promoted intramolecular Friedel-Crafts arylation of a functional group-specific 5-bromo-3-azabicyclo[3.3.1]nonane derivative.
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LUDA is a research project of Key Action 4 "City of Tomorrow & Cultural Heritage" of the programme "Energy, Environment and Sustainable Development" within the Fifth Framework Programme of the European Commission
Design of improved rail-to-rail low-distortion and low-stress switches in advanced CMOS technologies
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This paper describes the efficient design of an improved and dedicated switched-capacitor (SC) circuit capable of linearizing CMOS switches to allow SC circuits to reach low distortion levels. The described circuit (SC linearization control circuit, SLC) has the advantage over conventional clock-bootstrapping circuits of exhibiting low-stress, since large gate voltages are avoided. This paper presents exhaustive corner simulation results of a SC sample-and-hold (S/H) circuit which employs the proposed and optimized circuits, together with the experimental evaluation of a complete 10-bit ADC utilizing the referred S/H circuit. These results show that the SLC circuits can reduce distortion and increase dynamic linearity above 12 bits for wide input signal bandwidths.
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Wyner-Ziv (WZ) video coding is a particular case of distributed video coding, the recent video coding paradigm based on the Slepian-Wolf and Wyner-Ziv theorems that exploits the source correlation at the decoder and not at the encoder as in predictive video coding. Although many improvements have been done over the last years, the performance of the state-of-the-art WZ video codecs still did not reach the performance of state-of-the-art predictive video codecs, especially for high and complex motion video content. This is also true in terms of subjective image quality mainly because of a considerable amount of blocking artefacts present in the decoded WZ video frames. This paper proposes an adaptive deblocking filter to improve both the subjective and objective qualities of the WZ frames in a transform domain WZ video codec. The proposed filter is an adaptation of the advanced deblocking filter defined in the H.264/AVC (advanced video coding) standard to a WZ video codec. The results obtained confirm the subjective quality improvement and objective quality gains that can go up to 0.63 dB in the overall for sequences with high motion content when large group of pictures are used.
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We study the implications of the searches based on H -> tau(+)tau-by the ATLAS and CMS collaborations on the parameter space of the two-Higgs-doublet model (2HDM). In the 2HDM, the scalars can decay into a tau pair with a branching ratio larger than the SM one, leading to constraints on the 2HDM parameter space. We show that in model II, values of tan beta > 1.8 are definitively excluded if the pseudoscalar is in the mass range 110 GeV < m(A) < 145 GeV. We have also discussed the implications for the 2HDM of the recent dimuon search by the ATLAS collaboration for a CP-odd scalar in the mass range 4-12 GeV.
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This paper presents a direct power control (DPC) for three-phase matrix converters operating as unified power flow controllers (UPFCs). Matrix converters (MCs) allow the direct ac/ac power conversion without dc energy storage links; therefore, the MC-based UPFC (MC-UPFC) has reduced volume and cost, reduced capacitor power losses, together with higher reliability. Theoretical principles of direct power control (DPC) based on sliding mode control techniques are established for an MC-UPFC dynamic model including the input filter. As a result, line active and reactive power, together with ac supply reactive power, can be directly controlled by selecting an appropriate matrix converter switching state guaranteeing good steady-state and dynamic responses. Experimental results of DPC controllers for MC-UPFC show decoupled active and reactive power control, zero steady-state tracking error, and fast response times. Compared to an MC-UPFC using active and reactive power linear controllers based on a modified Venturini high-frequency PWM modulator, the experimental results of the advanced DPC-MC guarantee faster responses without overshoot and no steady-state error, presenting no cross-coupling in dynamic and steady-state responses.
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Este trabalho decorre de uma experiência de formação contínua de âmbito nacional, durante um ano letivo, relacionada com o ensino do português no 1º Ciclo no contexto do Programa Nacional de Ensino do Português (PNEP). Para se compreender o impacto da formação e do seu modelo, analisaram-se as produções escritas (do género narrativo e epistolar) dos alunos do 1º ao 4º ano de escolaridade, os resultados das Provas de Aferição de Língua Portuguesa do 4º ano, os inquéritos de avaliação dos formandos à própria formação, da competência da Comissão Nacional de Acompanhamento (CNA) e, ainda, as reflexões dos portefólios produzidos pelos formandos ao longo da formação. Em génese, pretende-se aferir de que modo esta formação interferiu nas aprendizagens e no desenvolvimento de competências dos alunos no domínio da língua materna, nomeadamente ao nível da escrita. Nessa perspetiva, são comparados dois grupos de alunos do mesmo agrupamento, do distrito de Lisboa, sendo o grupo experimental constituído pelos alunos cujos professores frequentaram a ação de formação PNEP e o grupo de controlo formado por alunos cujos professores nunca frequentaram a referida ação. Todavia, podendo o PNEP ser considerado como uma formação inovadora, porque se desenvolve em contexto, procura-se também saber como se sentiram os professores ao longo desta formação, bem como que repercussões e mais-valias obtiveram para as suas práticas pedagógicas e para a resolução real dos problemas vividos na sala de aula. Por fim, cruzando todos os dados de que se dispõe, aspira-se compreender o papel e o contributo da figura do formador no contexto PNEP, o que poderá conduzir a uma nova abordagem de formação, mais consentânea com o conceito de “mentoria”, e seus processos, do que com os pressupostos iniciais assentes numa lógica de “tutoria”. - This study originates from a one year education experience, nation wide, in the wake of the PNEP (Programa Nacional de Ensino do Português, in its maiden form) program. The aim is to understand how the model herein impacts first to fourth year primary school children’s learning and writing skills, how it influences the fourth year’s final exam results, and how it is reflected on practitioners’ (teachers undergoing the PNEP) performance evaluation inquires, and on concept development within their portfolios. In genesis, we seek to analyse whether the PNEP changed the way children attending primary school learn and master Portuguese, particularly its written expression. To do so, the study focus on two different publics, whereby an experimental group was build around a set of classes whose teachers had completed the PNEP education and training program, and a control group, set around a similar sample, but where teachers had no PNEP education or training at all. In addition, because PNEP might be considered as an advanced education model, we also wanted to disclosure how it adds to schoolteachers’ education techniques, and how it would help them solve daily ordinary problems within the classroom. Last but not the least, the study reveals that PNEP can change Portuguese standard education perspectives, changing classic tutorial methodologies towards a, more responsive, mentoring approach.
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Although it is always weak between RFID Tag and Terminal in focus of the security, there are no security skills in RFID Tag. Recently there are a lot of studying in order to protect it, but because it has some physical limitation of RFID, that is it should be low electric power and high speed, it is impossible to protect with the skills. At present, the methods of RFID security are using a security server, a security policy and security. One of them the most famous skill is the security module, then they has an authentication skill and an encryption skill. In this paper, we designed and implemented after modification original SEED into 8 Round and 64 bits for Tag.
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Mestrado em Engenharia Electrotécnica e de Computadores