883 research outputs found
Earthquakes from 1820 to 1936 in Grahamstown and surroundings (Eastern Cape Province, South Africa)
No full textThe seismicity of Grahamstown, in the Eastern Cape Province of South Africa, for the years between 1820 and 1936 is investigated with recourse to contemporaneous documentary sources, leading to the development of a seismic history incorporating consideration of the broader geo-political context. Individual studies of five regional events that were felt in Grahamstown during that period, and of one that was not, are presented. Each study includes the development of a full set of intensity data points (IDPs), which are used to determine reappraised epicentral locations and magnitudes, some of which differ significantly from previously listed parameters. The results thus obtained highlight the value of seeking out additional contemporary sources from different language groups when revisiting the source parameters of earthquakes for which no or only very limited instrumental information is available.Published45-783T. Pericolosità sismica e contributo alla definizione del rischioJCR Journalreserve
The Sussex Multimedia Frame Buffer
No full textThis paper describes work at the University of Sussex in the field of multimedia video and high resolution display control. This paper is the result of research carried out for the SMILE (SPARC Macrocell and Interface Library Elements) project, one of the coordinated set o f projects within Esprit III. The overall objective ofSMILE is to develop, within the Open Microprocessor systems Initiative (OMI) framework, a family o f SP ARC based library cells, both 32-bit processor-core and application-oriented, to provide the basis for a next generation family o f microprocessors/controliers that give the European systems industry a collective edge. The University of Sussex is required to design a system that provides 2-D graphics functions to support full motion video, image transformation and high resolution display control. In this paper we describe the approach taken in employing classic memory interleaving techniques together with an innovative memory access coordination approach and dedicated video hardware to provide a high bandwidth frame store, optimised for live video support.Eurographics Workshop on Graphics Hardwar
Reply to "Comment on 'Review: Strong Ground Motions--Have We Seen the Worst?' by Fleur O. Strasser and Julian J. Bommer" by Heriberta Castanos and Cinna Lomnitz
No full textReply to “Comment on ‘Influence of Focal Mechanism in Probabilistic Seismic Hazard Analysis’ by Vincenzo Convertito and André Herrero,” by F. O. Strasser, V. Montaldo, J. Douglas, and J. J. Bommer
No full textWe thank F. O. Strasser, V. Montaldo, J. Douglas, and J. J. Bommer for the interest they have shown in our article (Convertito and Herrero, 2004). Strasser et al. (2006) present a critical comment of our work arguing that the solution proposed by Bommer et al. (2003) is a better solution. Note that the authors are nearly the same in both article and comment, except for V. Montaldo. Because this brief article is a reply, we will focus on the arguments directly concerning our article. The main objection supported by Strasser et al. (2006) is that the method we proposed is not appropriate to "styleof-faulting" correction. We completely agree with this assertion because it is simply not the scope of our article. We speak about "focal mechanism" intended as radiation pattern and nothing else. This point is clearly stated in the introduction of Convertito and Herrero (2004): "in this article we consider that the focal mechanism influence is only expressed by radiation pattern changes. In particular we do not consider any tectonic influence, stress drop variation or dynamic effects." The style-of-faulting parameter, even if its identity is blurred (e.g., Bommer et al., 2003), is an empirical definition of a complex set of physical conditions including the tectonic regime, the medium behavior, rock mechanics, rupture dynamics, and so on. In our opinion, the style of faulting is simply too complex to be used directly in our approach. Because the scope of our article is to show how it is possible to insert inside the main equation of probabilistic seismic-hazard analysis (PSHA; e.g., Cornell, 1968), simple physical parameters of the seismic source, that is, how it is possible to integrate deterministic parameters inside a probabilistic approach, we have chosen a small target, limiting ourselves only to the radiation pattern. We believe that the same approach can be used to insert many other parameters of the seismic source inside PSHA by using only a theoretical approach such as the fault strike (which has already been shown by Convertito, 2004), the directivity and stress drop. The second important argumentation is that a method based on regression (i.e., Bommer et al., 2003) is better than the method we propose. Once again we agree with Strasser et al. (2006) and this is clearly stated in the conclusion of our article: "when an attenuation law, including a faulting style parameter, is available for a given region, the use of this attenuation law gives a more reliable estimate of the hazard than the one obtained using the corrective coefficient we propose in this article."Published754–756ope
An O(log N) Parallel Time Exact Hidden-LineAlgorithm
No full text"Parallel algorithms are given for the exact solution of the hidden-line problem. Most of the parallel algorithms proposed for visibility problems in the literature give approximate solutions. and thus cannot yield an upper bound on the complexity of the particular problem. The first algorithm proposed here is worth mentioning not only for its simplicity. but also from a practical point of view: a speed up of a factor P is achieved by using P processors. l"";;P"";;N. where N is the number of edges used to describe a polygonal scene. Additionally. the problem of aliasing inherent with approximation methods is avoided.The significance of the second algorithm, which is based on the first one, is mainly on the theoretical level: it is used to establish the parallel complexity of the hidden-line problem. The sequential complexity of this problem has recently been proved to be e(N2). and now we can prove that in the parallel case the problem is in the complexity class NC, Le., it can be solved in time polynomial in logN by using a number of processors polynomial in N, assuming any reasonable model of parallel computation. More particularly, an O(logN) parallel time solution is given which cannot be further improved even if arbitrarily many processors of a concurrent read, exclusive write parallel RAM model are available."Eurographics Workshop on Graphics Hardwar
Ensino do conceito de referencial segundo a f?sica cl?ssica e moderna a partir de uma unidade de ensino potencialmente significativa - UEPS
No full textCom a inser??o da F?sica Moderna na Educa??o B?sica estamos proporcionando ao estudante o estudo te?rico de um conte?do que est? muito presente no dia a dia dos alunos, principalmente com as novas tecnologias e m?dias. Por?m ? necess?rio que o estudante adquira conhecimento de maneira significativa, percebendo a rela??o dos conhecimentos estudados em sala de aula com seu cotidiano e n?o de maneira desvinculada. ? neste sentido que tratam os documentos oficiais que subsidiam a Educa??o B?sica no Brasil, no que se refere ao Ensino da F?sica, colocando o trabalho interdisciplinar como uma maneira de tornar poss?vel essa rela??o F?sica ? cotidiano. No presente trabalho buscou-se produzir uma Unidade
de Ensino Potencialmente Significativa e, junto a ela, um material did?tico sobre o conceito de Referencial. A UEPS foi planejada para alunos no final do Ensino Fundamental, 9? ano, e teve como fundamenta??o te?rica a teoria de David Ausubel sobre Aprendizagem Significativa. No material, o tema ? tratado a partir da F?sica Cl?ssica e da F?sica Moderna. Para elaborar a Unidade e o material foi realizada uma revis?o em alguns peri?dicos relevantes da literatura da ?rea de Ensino de F?sica. Espera-se que este trabalho possa ser uma op??o de material potencialmente significativo que relacione os conceitos com o cotidiano do aluno
Influence from genetic variability on opioid use for cancer pain: a European genetic association study of 2294 cancer pain patients
No full textCancer pain patients need variable opioid doses. Preclinical and clinical studies suggest that opioid efficacy is related to genetic variability. However, the studies have small samples, findings are not replicated, and several candidate genes have not been studied. Therefore, a study of genetic variability with opioid doses in a large population using a confirmatory validation population was warranted. We recruited 2294 adult European patients using a World Health Organization (WHO) step III opioid and analyzed single nucleotide polymorphisms (SNPs) in genes with a putative influence on opioid mechanisms. The patients' mean age was 62.5 years, and the average pain intensity was 3.5. The patients' primary opioids were morphine (n=830), oxycodone (n=446), fentanyl (n=699), or other opioids (n=234). Pain intensity, time on opioids, age, gender, performance status, and bone or CNS metastases predicted opioid dose and were included as covariates. The patients were randomly divided into 1 development sample and 1 validation sample. None of 112 SNPs in the 25 candidate genes OPRM1, OPRD1, OPRK1, ARRB2, GNAZ, HINT1, Stat6, ABCB1, COMT, HRH1, ADRA2A, MC1R, TACR1, GCH1, DRD2, DRD3, HTR3A, HTR3B, HTR2A, HTR3C, HTR3D, HTR3E, HTR1, or CNR1 showed significant associations with opioid dose in both the development and the validation analyzes. These findings do not support the use of pharmacogenetic analyses for the assessed SNPs to guide opioid treatment. The study also demonstrates the importance of validating findings obtained in genetic association studies to avoid reporting spurious associations as valid findings. To elicit knowledge about new genes that influence pain and the need for opioids, strategies other than the candidate gene approach is needed
Super Resolution Volume Rendering Hardware
No full textThe resolution obtained in volume rendering is greatly increased over known methods through the introduction of super resolution techniques which make it possible to enlarge the view o f the dataset without the introduction of unnecessary positional, gradient and opacity errors. In this paper our "Super Resolution" technique will be introduced along with a corresponding hardware design.Tenth Eurographics Workshop on Graphics Hardwar
Comment on "Influence of focal mechanism in probabilistic seismic hazard analysis" by Vincenzo Convertito and André Herrero
No full textThe influence of style-of-faulting on strong ground motions has been the subject of debate for some time. Although some controversy persists, the general consensus is that ground motions produced by reverse faults are higher than those produced by normal faults, whereas motions from strike-slip faults are somewhere in between. In a recent article, Convertito and Herrero (2004) derived a correction factor for focal mechanism to be applied to predictive equations. This issue was previously addressed by Bommer et al. (2003). Although this article is cited by Convertito and Herrero, it seems that its aims and scope were not well understood, and we would therefore like to clarify what the method presented therein entails, especially because we feel that Convertito and Herrero's approach of characterizing focal mechanisms based solely on the radiation pattern is difficult to justify
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