146 research outputs found

    Augmented Reality for Subsurface Utility Engineering, Revisited

    Get PDF

    Sub-Cycle Strong-Field Interferometry

    Full text link
    A nonlinear interferometry scheme is described theoretically to induce and resolve electron wave- function beating on time scales shorter than the optical cycle of the time-delayed pump and probe pulses. By employing two moderately intense few-cycle laser fields with a stable carrier-envelope phase, a large range of the entire electronic level structure of a quantum system can be retrieved. In contrast to single-photon excitation schemes, the retrieved electronic states include levels that are both dipole- and non-dipole-accessible from the ground electronic state. The results show that strong-field interferometry can reveal both high-resolution and broad-band spectral information at the same time with important consequences for quantum-beat spectroscopy on attosecond or even shorter time scales.Comment: first submitted on April 19, 201

    Evolutionary Algorithms for Segment Optimization in Vectorial GP [Poster]

    Get PDF
    875441 Vektor-basierte Genetische Programmierung fĂŒr Symbolische Regression und Klassifikation mit Zeitreihen (SymRegZeit), funded by the Austrian Research Promotion Agency FFG. It was also partially supported by FCT, Portugal, through funding of research units MagIC/NOVA IMS (UIDB/04152/2020) and LASIGE (UIDB/00408/2020 and UIDP/00408/2020).Vectorial Genetic Programming (Vec-GP) extends regular GP by allowing vectorial input features (e.g. time series data), while retaining the expressiveness and interpretability of regular GP. The availability of raw vectorial data during training, not only enables Vec-GP to select appropriate aggregation functions itself, but also allows Vec-GP to extract segments from vectors prior to aggregation (like windows for time series data). This is a critical factor in many machine learning applications, as vectors can be very long and only small segments may be relevant. However, allowing aggregation over segments within GP models makes the training more complicated. We explore the use of common evolutionary algorithms to help GP identify appropriate segments, which we analyze using a simplified problem that focuses on optimizing aggregation segments on fixed data. Since the studied algorithms are to be used in GP for local optimization (e.g. as mutation operator), we evaluate not only the quality of the solutions, but also take into account the convergence speed and anytime performance. Among the evaluated algorithms, CMA-ES, PSO and ALPS show the most promising results, which would be prime candidates for evaluation within GP.publishersversionpublishe

    Managed Automated Driving (MAD) - a Concept for Empowering Road Infrastructure

    Get PDF
    Current automated vehicles, even when appended with C-ITS support, require a vast number of sensors of various types per vehicle to empower them to cope with the variety of possible situations. However, most of these sensors are not required on large parts of the route while in addition, the horizon of vehiclebased sensors is very limited. On the other hand, roadside infrastructure can be placed fully matching specific local requirements and therefore ensuring optimal sensor performance, while communication can provide basically unlimited sensor ranges. Replacing vehicle-based sensors by infrastructuremounted ones can therefore be a solution. Using this approach on dedicated routes (e.g. for public or freight transport) with fleet vehicles can be a starting point to make automated driving safer and economically beneficial. The German national project "MAD Urban" is investigating means of additional roadside support, including localization, object detection, and even vehicle control by infrastructure

    Netzwerk Ökologische PflanzenzĂŒchtung: Möglichkeiten und Methoden, Grenzen zwischen klassischen und „gentechnischen“ ZĂŒchtungsmethoden, partizipative PflanzenzĂŒchtung

    Get PDF
    Das Netzwerk Ökologische PflanzenzĂŒchtung hatte zum Ziel, die verschiedenen Akteure aus dem Sektor der ökologischen PflanzenzĂŒchtung besser zu vernetzen und zu koordinieren sowie den Austausch von Ideen und Informationen zu ermöglichen. Das Projekt wurde vor dem Hintergrund der starken AbhĂ€ngigkeit des ökologischen Anbaus von konventionell gezĂŒchteten Sorten sowie dem stetig zunehmenden Einsatz molekularbiologischer Techniken in der Pflanzenzucht konzipiert. Auf Grund dieser Entwicklungen bestand ein großer Bedarf sowohl an Informationen ĂŒber ZĂŒchtungstechniken und gemeinsamem Austausch hierzu als auch konkret an besser auf die Bedingungen des Ökolandbaus abgestimmtem Vermehrungsmaterial. In den ĂŒber das Netzwerk ausgerichteten Workshops traten ZĂŒchter, Anbauer, Berater, Vertreter der verschiedenen AnbauverbĂ€nde und Wissenschaftler in einen gemeinsamen Dialog. Durch die Einbeziehung aller Akteure konnte das Projekt in vielen Bereichen einen Anschub oder Beitrag zur Weiterentwicklung der ökologischen PflanzenzĂŒchtung leisten. In der Projektlaufzeit erfolgte unter anderem eine deutlichere Positionierung der AnbauverbĂ€nde hinsichtlich bestimmter ZĂŒchtungstechniken sowie eine diesbezĂŒgliche Sensibilisierung. Daneben wurden Diskussionen und Entwicklungen zur besseren BĂŒndelung und Finanzierung ökologischer ZĂŒchtungsaktivitĂ€ten sowie die GrĂŒndung neuer ökologischer ZĂŒchtungsinitiativen und verbandsinterner ZĂŒchtungsforen angeregt. Das Projekt verstand sich in erster Linie als Networking Projekt, um in den Bereichen Austausch von Ideen und Informationen sowie Bereitstellung von geeignetem Vermehrungsmaterial Fortschritte zu erzielen. Neben den Workshops wurde es durch Praxisversuche flankiert um Sorten aus den Bereichen Ackerkulturen, GemĂŒsekulturen, Obstkulturen und Reben unter den Bedingungen des ökologischen Landbaus zu prĂŒfen und fĂŒr die Praxis bei Feldtagen zu demonstrieren. Die Versuche und Demonstrationen konnten unter anderem dazu beitragen, dass Praktiker zum Wintererbsenanbau animiert wurden, eine ökologisch gezĂŒchtete Speisegerstensorte sowie zwei Wintererbsensorten zur Anmeldung gebracht wurden. Durch den Versuchsbau konnten außerdem mehrere GemĂŒsesorten angemeldet, eine schorfresistente Apfelsorte etabliert und die Bekanntheit und AnbauflĂ€che von pilzwiderstandsfĂ€higen Rebsorten (Piwi) gesteigert werden. Schließlich wurden Fragestellungen in weitere Forschungsprojekte eingespeist und wichtige Impulse fĂŒr die ökologisch-partizipative PflanzenzĂŒchtung in Deutschland gesetzt

    The influence of strut waviness on the tensile response of lattice materials

    Get PDF
    Recent advances in additive manufacturing methods make it possible, for the first time, to manufacture complex micro-architectured solids that achieve desired stress versus strain re- sponses. Here, we report experimental measurements and associated finite element (FE) calcu- lations on the effect of strut shape upon the tensile response of two-dimensional (2D) lattices made from low-carbon steel sheets. Two lattice topologies are considered: (i) a stretching-dominated triangular lattice and (ii) a bending-dominated hexagonal lattice. It is found that strut waviness can enhance the ductility of each lattice, particularly for bending-dominated hexagonal lattices. Manufacturing imperfections such as undercuts have a small effect on the ductility of the lattices but can significantly reduce the ultimate tensile strength. FE simulations provide additional insight into these observations and are used to construct design maps to aid the design of lattices with specified strength and ductility

    Renal sympathetic denervation restores aortic distensibility in patients with resistant hypertension: data from a multi-center trial

    Get PDF
    Renal sympathetic denervation (RDN) is under investigation as a treatment option in patients with resistant hypertension (RH). Determinants of arterial compliance may, however, help to predict the BP response to therapy. Aortic distensibility (AD) is a well-established parameter of aortic stiffness and can reliably be obtained by CMR. This analysis sought to investigate the effects of RDN on AD and to assess the predictive value of pre-treatment AD for BP changes. We analyzed data of 65 patients with RH included in a multicenter trial. RDN was performed in all participants. A standardized CMR protocol was utilized at baseline and at 6-month follow-up. AD was determined as the change in cross-sectional aortic area per unit change in BP. Office BP decreased significantly from 173/92 ± 24/16 mmHg at baseline to 151/85 ± 24/17 mmHg (p < 0.001) 6 months after RDN. Maximum aortic areas increased from 604.7 ± 157.7 to 621.1 ± 157.3 mm2 (p = 0.011). AD improved significantly by 33% from 1.52 ± 0.82 to 2.02 ± 0.93 × 10-3 mmHg-1 (p < 0.001). Increase of AD at follow-up was significantly more pronounced in younger patients (p = 0.005) and responders to RDN (p = 0.002). Patients with high-baseline AD were significantly younger (61.4 ± 10.1 vs. 67.1 ± 8.4 years, p = 0.022). However, there was no significant correlation of baseline AD to response to RDN. AD is improved after RDN across all age groups. Importantly, these improvements appear to be unrelated to observed BP changes, suggesting that RDN may have direct effects on the central vasculature

    Age of Izu-Bonin-Mariana arc basement

    Get PDF
    Documenting the early tectonic and magmatic evolution of the Izu–Bonin–Mariana (IBM) arc system in the Western Pacific is critical for understanding the process and cause of subduction initiation along the current convergent margin between the Pacific and Philippine Sea plates. Forearc igneous sections provide firm evidence for seafloor spreading at the time of subduction initiation (52 Ma) and production of “forearc basalt”. Ocean floor drilling (International Ocean Discovery Program Expedition 351) recovered basement-forming, low-Ti tholeiitic basalt crust formed shortly after subduction initiation but distal from the convergent margin (nominally reararc) of the future IBM arc (Amami Sankaku Basin: ASB). Radiometric dating of this basement gives an age range (49.3–46.8 Ma with a weighted average of 48.7 Ma) that overlaps that of basalt in the present-day IBM forearc, but up to 3.3 m.y. younger than the onset of forearc basalt activity. Similarity in age range and geochemical character between the reararc and forearc basalts implies that the ocean crust newly formed by seafloor spreading during subduction initiation extends from fore- to reararc of the present-day IBM arc. Given the age difference between the oldest forearc basalt and the ASB crust, asymmetric spreading caused by ridge migration might have taken place. This scenario for the formation of the ASB implies that the Mesozoic remnant arc terrane of the Daito Ridges comprised the overriding plate at subduction initiation. The juxtaposition of a relatively buoyant remnant arc terrane adjacent to an oceanic plate was more favourable for subduction initiation than would have been the case if both downgoing and overriding plates had been oceanic

    Phylogeographic Analysis Elucidates the Influence of the Ice Ages on the Disjunct Distribution of Relict Dragonflies in Asia

    Get PDF
    Unusual biogeographic patterns of closely related groups reflect events in the past, and molecular analyses can help to elucidate these events. While ample research on the origin of disjunct distributions of different organism groups in the Western Paleartic has been conducted, such studies are rare for Eastern Palearctic organisms. In this paper we present a phylogeographic analysis of the disjunct distribution pattern of the extant species of the strongly cool-adapted Epiophlebia dragonflies from Asia. We investigated sequences of the usually more conserved 18 S rDNA and 28 S rDNA genes and the more variable sequences of ITS1, ITS2 and CO2 of all three currently recognised Epiophlebia species and of a sample of other odonatan species. In all genes investigated the degrees of similarity between species of Epiophlebia are very high and resemble those otherwise found between different populations of the same species in Odonata. This indicates that substantial gene transfer between these populations occurred in the comparatively recent past. Our analyses imply a wide distribution of the ancestor of extant Epiophlebia in Southeast Asia during the last ice age, when suitable habitats were more common. During the following warming phase, its range contracted, resulting in the current disjunct distribution. Given the strong sensitivity of these species to climatic parameters, the current trend to increasing global temperatures will further reduce acceptable habitats and seriously threaten the existences of these last representatives of an ancient group of Odonata
    • 

    corecore