437 research outputs found
EVALUATION OF THE ANALYSIS METHOD FOR THE DESIGN OF FRAME STRUCTURES
By the use of numerical methods and the rapid development of computer technology in the recent years, a large variety, complexity, refinement and capability of partial models have been achieved. This can be noticed in the evaluation of the reliability of structures, e.g. the increased use of spatial structural systems. For the different fields of civil engineering, well developed partial models already exist. Because these partial models are most often used separately, the general view is not entirely illustrated. Until now, there has been no common methodology for evaluating the efficiency of models; the trust in the prediction of a special engineering model has generally relied on the engineer’s experience. In this paper the basics of evaluation of simple models and coupled partial models of frame structures will be discussed using sustainable numerical methods. Furthermore, quality classes (levels) of design tasks will be defined based on their practical relevance. In addition, analysis methods will be systemized. After analysis of different published assessment methods, it may be noted, that the Efficiency Indicator Method (EWM) is most suitable for the observed evaluation problem. Therefore, the EWM was modified to the Model Efficiency Analysis (MEA) for the purpose of a holistic evaluation. The criteria are characterized by two groups, benefit and expenditure, and it is possible by calculating the quotient (benefit/expenditure) to make a statement about the efficiency of the observed models. Presently, the expenditure value is not a subject of investigation, and so the model efficiency is calculated only by the benefit value. This paper also contains the associated criteria catalog, different normalization methods, as well as weighting possibilities
Post-rift sequence architecture and stratigraphy in the Oligo-Miocene Sardinia rift (Western Mediterranean Sea)
Rift basins provide important sedimentary archives to reconstruct past tectonic and climatic conditions. Understanding their sedimentary history is, however, largely hampered by the competing influence of tectonic versus climatic forcing. The aim of this study is to comprehend the effects of local to regional tectonic and global climatic/eustatic changes on shallow marine depositional systems in the Sardinia Rift (Western Mediterranean Sea). For this purpose the stratigraphic and depositional relations of a mixed siliciclastic-carbonate ramp at the Porto Torres Basin margin were studied along extensive proximal to distal transects. Three depositional sequences (DS1 to DS3) of late Burdigalian to early Serravallian age have been identified, which are separated by erosional unconformities. Each contains a lower trans- gressive part and an upper regressive part. The former includes shoreface sandstone (DS2) or coral reef (DS3) deposits on the proximal ramp and channelized sheet sandstone (DS1) or basinal mudstone (DS2, DS3) deposits on the distal ramp, typically recording an upsection trend of sediment starvation. The latter is represented by basinward-prograding coralline red algal carbonate wedges due to enhanced shallow water carbonate production rates. In the long term, the depositional evolution from DS1 to DS3 reveals basin margin progradation associated with decreasing siliciclastic supply. Integrated calcareous nannoplankton-foraminiferal-pectinid biostratigraphy links the depositional sequences to third-order sea-level cycles and allows to correlate the erosional unconformities at the top of DS1 and DS2 with the Bur 5/Lan 1 and Lan 2/Ser 1 sequence boundaries. The improved sequence stratigraphic framework enables better regional and global correlations. This shows that rhodalgal carbonate slopes started prograding in the western branch of the Sardinia Rift during the late Burdigalian because (1) of a worldwide bloom of rhodalgal facies, and (2) decreasing tectonic activity at the transition from the syn- rift to the post-rift stage caused a continuous reduction of the siliciclastic sediment input
Reading Words Hurts: The impact of pain sensitivity on people’s ratings of pain-related words
This study explores the relation between pain sensitivity and the cognitive processing of words. 130 participants evaluated the pain-relatedness of a total of 600 two-syllabic nouns, and subsequently reported on their own pain sensitivity. The results demonstrate that pain-sensitive people (based on their self-report) associate words more strongly with pain than less sensitive people. In particular, concrete nouns like syringe, wound, knife, and cactus, are considered to be more pain-related for those who are more pain-sensitive. We discuss our results in the light of three theoretical frameworks – cognitive bias, prototype theory, embodied account. We argue that the latter is best suited to explain the results of this study in the sense in which it implies the principle of body specificity, according to which different bodily characteristics lead to corresponding differences in the way in which people construct concepts and word meanings
A massively parallel semi-Lagrangian solver for the six-dimensional Vlasov-Poisson equation
This paper presents an optimized and scalable semi-Lagrangian solver for the
Vlasov-Poisson system in six-dimensional phase space. Grid-based solvers of the
Vlasov equation are known to give accurate results. At the same time, these
solvers are challenged by the curse of dimensionality resulting in very high
memory requirements, and moreover, requiring highly efficient parallelization
schemes. In this paper, we consider the 6d Vlasov-Poisson problem discretized
by a split-step semi-Lagrangian scheme, using successive 1d interpolations on
1d stripes of the 6d domain. Two parallelization paradigms are compared, a
remapping scheme and a classical domain decomposition approach applied to the
full 6d problem. From numerical experiments, the latter approach is found to be
superior in the massively parallel case in various respects. We address the
challenge of artificial time step restrictions due to the decomposition of the
domain by introducing a blocked one-sided communication scheme for the purely
electrostatic case and a rotating mesh for the case with a constant magnetic
field. In addition, we propose a pipelining scheme that enables to hide the
costs for the halo communication between neighbor processes efficiently behind
useful computation. Parallel scalability on up to 65k processes is demonstrated
for benchmark problems on a supercomputer
Multi-Level Fine-Tuning, Data Augmentation, and Few-Shot Learning for Specialized Cyber Threat Intelligence
Gathering cyber threat intelligence from open sources is becoming
increasingly important for maintaining and achieving a high level of security
as systems become larger and more complex. However, these open sources are
often subject to information overload. It is therefore useful to apply machine
learning models that condense the amount of information to what is necessary.
Yet, previous studies and applications have shown that existing classifiers are
not able to extract specific information about emerging cybersecurity events
due to their low generalization ability. Therefore, we propose a system to
overcome this problem by training a new classifier for each new incident. Since
this requires a lot of labelled data using standard training methods, we
combine three different low-data regime techniques - transfer learning, data
augmentation, and few-shot learning - to train a high-quality classifier from
very few labelled instances. We evaluated our approach using a novel dataset
derived from the Microsoft Exchange Server data breach of 2021 which was
labelled by three experts. Our findings reveal an increase in F1 score of more
than 21 points compared to standard training methods and more than 18 points
compared to a state-of-the-art method in few-shot learning. Furthermore, the
classifier trained with this method and 32 instances is only less than 5 F1
score points worse than a classifier trained with 1800 instances
Coastal landscape evolution in the Wilpattu National Park (NW Sri Lanka) linked to changes in sediment supply and rainfall across the Pleistocene–Holocene transition
Coastal sand dunes are sediment archives which can be used to reconstruct periods of aridity and humidity, past wind strength and variations in the sediment supply related to sea-level changes. In this manner, the sedimentary record of fossil coastal dunes in Sri Lanka provides evidence for environmental and climatic changes during the late Pleistocene and Holocene. As yet, these environmental shifts are poorly resolved because the sedimentary facies and their depositional architecture have not been studied and only very few age constraints are available. Facies analysis of a lithological section at the Point Kurdimalai sea cliff in the Wilpattu National Park (NW Sri Lanka) reveals a striking resemblance to the stratigraphic succession associated with the Teri Sands in southeastern India, which is better dated. The reason is that deposition occurred under the same geological, climatic and geomorphological conditions in the two regions. This special situation allows for litho- and climate stratigraphic correlations across the Gulf of Mannar and links the landscape evolution at Point Kudrimalai to late Quaternary climatic events and sea-level changes. Our results show that the formation of red coastal dunes (Red Beds) in Sri Lanka was a multi-phase process across the Pleistocene–Holocene boundary and hence the differentiation between an Older Group of Plio-Pleistocene age (including the Red Beds) and a Younger Group of Holocene age in the Quaternary stratigraphic chart for Sri Lanka is not justified
Entwicklung der Faziesverteilung eines Riffkomplexes im Korallenoolith (Oberjura) des Osterwaldes (Niedersachsen)
The Hainholz quarry in the Osterwald hills of NW-Germany is the most impressive outcrop in the Lower Saxony Basin exposing Late Jurassic (Korallenoolith, Oxfordian) coral buildups. The Korallenoolith deposits in the quarry commence with a oolitic sequence about 20 m thick which is limited by a distinctive hardground at its top. This sequence is overlain by the so called “Obere Korallenbank”-Member about 13 m in thickness which is mainly build up by coral reef complexes. Throughout a lateral extend of about 400 m exposed in the quarry, the Obere Korallenbank Member shows numerous pillar-shaped reefal build ups which are flanked by a reefal debris limestone. The coral fauna of the in situ reefal bioconstructions comprises not less than 37 taxa most of which have been described from the Lower Saxony Basin for the first time. Probably, the pillar-shaped reefs formed a small positive relief of only a few dm against the debris deposits during deposition. The interreef debris limestones in the lower and middle part of the Obere Korallenbank Member show three intercalated biostromal coral layers. In the upper part of the member, the interreef facies is represented by a mikritic peloidal limestone rich in sponge remains and, unusual in such a depositional environment, ammonites (Dichotomo-sphinctes bifurcatoides, D. sp.). Additionaly, at the top of of the peloidal limestone a layer enriched in nerineids and other gastropods limits the reefal constructions of the Obere Korallenbank Member against the overlying “humeralis-Oolith” sequence. On the basis of the facies development of this depositional sequence the reef formation in relation to sealevel changes is discussed.Der Steinbruch am Hainholz (Rohstoffbetriebe Eldagsen, Werk Wülfinghausen) im Osterwald (NW-Deutschland) bietet den eindrucksvollsten Einblick in die oberjurazeitlichen (Korallenoolith, Oxfordium) Korallenvorkommen des Niedersächsischen Beckens. Er erschließt den gesamten Korallenoolith, der hier mit einer nicht weiter gliederbaren, etwa 20 m mächtigen Kalkoolith-Folge einsetzt. Sie wird von einem markanten Hartgrund abgeschlossen, auf den im stratigraphischen Niveau der sogenannten „Oberen Korallenbank“ ein insgesamt 13 m mächtiger Korallenriffkomplex folgt. Der auf ca. 400 m Lateralerstreckung erschlossene Riffkomplex besteht aus zahlreichen stotzenartigen Riffkörpern. Die Korallenfauna dieser in situ-Biokonstruktionen, die sich vermutlich nur wenige m über den Sedimentspiegel erhoben, umfaßt mindestens 37 Taxa, von denen ein Großteil erstmals im NW-deutschen Oberjura belegt ist. Einen wesentlichen Bestandteil der Korallenstotzen bildet Mikrobialith, der wie die Korallen intensiv angebohrt ist. Im unteren Teil des Riff-Horizontes werden die Riffkörper von einem im bewegten Flachwasser abgelagerten Riffschuttkalkstein flankiert, der wiederholt von (drei) bankartigen, im Steinbruchbereich durchhaltenden Korallenlagen unterbrochen wird. Von anderen NW-deutschen Lokalitäten sind solche Riffschuttkalke nicht bekannt. Im Hangenden des Riffschuttkalksteins folgt ein rhaxenrei-cher, mikritischer Peloidkalkstein mit für den Korallenoolith ungewöhnlich zahlreichen Ammonitenresten (Dichotomos-phinctes sp., D. bifurcatoides). Sein Top ist durch einen Anreicherungshorizont von Nerineen und Kleingastropoden gekennzeichnet, der das Ende des Riffwachstums markiert und zum humeralis-OoYnh überleitet. Aus der faziellen Abfolge vom Liegenden bis in das Hangende der Oberen Korallenbank wird neben einer Interpretation der steuerndem Faktoren der Riffentwicklung und -Zerstörung die Entwicklungsgeschichte des Meeresspiegels abgeleitet
ThreatCrawl: A BERT-based Focused Crawler for the Cybersecurity Domain
Publicly available information contains valuable information for Cyber Threat
Intelligence (CTI). This can be used to prevent attacks that have already taken
place on other systems. Ideally, only the initial attack succeeds and all
subsequent ones are detected and stopped. But while there are different
standards to exchange this information, a lot of it is shared in articles or
blog posts in non-standardized ways. Manually scanning through multiple online
portals and news pages to discover new threats and extracting them is a
time-consuming task. To automize parts of this scanning process, multiple
papers propose extractors that use Natural Language Processing (NLP) to extract
Indicators of Compromise (IOCs) from documents. However, while this already
solves the problem of extracting the information out of documents, the search
for these documents is rarely considered. In this paper, a new focused crawler
is proposed called ThreatCrawl, which uses Bidirectional Encoder
Representations from Transformers (BERT)-based models to classify documents and
adapt its crawling path dynamically. While ThreatCrawl has difficulties to
classify the specific type of Open Source Intelligence (OSINT) named in texts,
e.g., IOC content, it can successfully find relevant documents and modify its
path accordingly. It yields harvest rates of up to 52%, which are, to the best
of our knowledge, better than the current state of the art.Comment: 11 pages, 9 figures, 5 table
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