172 research outputs found

    Glaubwürdigkeit und Einsatz des szenariobasierten X-in-the-Loop-Tests für Fahrerassistenzsysteme

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    Fahrerassistenzsysteme tragen gerade im Bereich der Nutzfahrzeuge zur Verkehrssicherheit bei. Darüber hinaus bietet das hochautomatisierte Fahren neue Geschäftsmodelle. Eine zentrale Herausforderung bei der Entwicklung dieser Systeme ist die steigende Breite und Tiefe der Testfälle. Bereits in heutigen Entwicklungsprojekten stoßen vorhandene Realtestkapazitäten an ihre Grenzen. Daher sind neue Methoden zum Test von Fahrerassistenzsystemen erforderlich. Die Kombination aus szenariobasiertem Testen und X-in-the-Loop-Testumgebungen ist ein vielversprechender Ansatz. In dieser Dissertation werden drei Einsatzmöglichkeiten des szenariobasierten XiL-Tests in einem Serien-Entwicklungsprojekt eingeführt und diskutiert. Als besonders geeignet wird hierbei der Einsatz beim Software-Qualifizierungstest bewertet und in einem Prozessentwurf weiter detailliert. Schwerpunkt ist die Zuordnung von Szenarien auf Testumgebungen mit dem Ziel, die Testabdeckung, die Glaubwürdigkeit der Testergebnisse und die Effizienz der Testdurchführung zu optimieren. Ein entscheidender Prozessschritt ist die sogenannte Glaubwürdigkeitsbewertung. Diese bewertet ein konkretes Szenario in einer spezifischen Testumgebung und besteht je nach Konfidenzanforderung aus den drei Schritten Prädiktion, Plausibilisierung und Validierung. In der Prädiktion werden mithilfe von Unsicherheitsmodellen für drei Subsysteme der XiL-Umgebung und einer Monte-Carlo-Simulation Testergebnis-Verteilungen generiert und mit einem Multinomialansatz Konfidenzintervalle ermittelt. Die Plausibilisierung prüft mithilfe von Pass/Fail-Kriterien und Szenariodistanzmaßen die Äquivalenz einzelner Testausführungen in XiL und Realtest. Bei der Validierung findet ein statistischer Abgleich der Testergebnis-Verteilungen aus XiL und Realtest mithilfe des Barnard-Tests statt. Die Glaubwürdigkeitsbewertung wird auf Basis von Software-in-the-Loop-Daten eines Entwicklungsprojekts für Fahrerassistenzsysteme für insgesamt sieben konkrete Szenarien evaluiert

    Barriers to Early Detection in Women Experiencing a Postpartum Hemorrhage: An Integrative Review

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    Abstract Aim: The aim of this integrative review is to explore barriers to early detection in women experiencing postpartum hemorrhage. Background: Women in the United States are more likely to die from childbirth complications than any other women living in other developed countries. Despite advances in maternity care, postpartum hemorrhage is the cause of nearly 70,000 maternal deaths every year, comparable to one woman dying of postpartum hemorrhage blood loss every eight minutes. Most maternal deaths are avoidable, as the solutions to prevent and manage these deadly complications are well known. Risk factors, assessment tools, causes, interventions, and outcomes are well studied and have extensive evidence-based research to support. However, significant challenges, such as accurate monitoring, assessment of blood loss, early identification of risk factors, and timely recognition of postpartum hemorrhage remain. Very few studies have explored where the gap lies in patient care, as postpartum hemorrhage continues to remain the leading cause of maternal mortality and morbidity worldwide. Method: This integrative review followed Whittemore and Knafl’s five-step methodologic framework. A comprehensive search was conducted, identifying studies published between 2016 and 2023 using predetermined inclusion criteria, exclusion criteria, and search terms. Nursing databases that were searched included CINAHL, OVID Nursing Collection, Health Source Nursing, Medline Complete, and PubMed. Data was screened and all sampling decisions were made transparent, justified, displayed, and outlined in a PRISMA flowchart. The retrieved articles were then critically appraised for quality, reliability, value, and relevance to the context using the Johns Hopkins Nursing Evidence-Based Practice Appraisal Tool. A thematic analysis was utilized that revealed emergent themes and subthemes in relevance to the aim of this integrative review. Results: The thematic analysis identified six main themes that included undervaluing preventative measures, knowledge gap of detection practices, inadequate exposure, availability of resources, increasing disparities, and timely referral. Sixteen subthemes emerged and are described more in-depth among the central themes. While most studies exemplified more than one theme, no single theme was present in all ten reviewed studies. Conclusion: The evidence elaborated on in this review highlights the barriers to early detection to bring awareness, share education, and make recommendations for ways to remove these barriers to help prevent poor maternal outcomes. Improvement in maternal health will require dedicated efforts in screening, prevention, detection, education, and management, beginning in the preconception period and continuing throughout the first year postpartum. Improving the quality of care and health outcomes can be done with thorough preparation, anticipating risk factors, coordinating a healthcare team, and ensuring access to care with timely interventional procedures. Further research is needed on screening tools, training programs, and care management worldwide as healthcare is striving to improve maternal morbidity and mortality

    Developments in multiscale ONIOM and fragment methods for complex chemical systems

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    Multiskalenprobleme werden in der Computerchemie immer allgegenwärtiger und bestimmte Klassen solcher Probleme entziehen sich einer effizienten Beschreibung mit den verfügbaren Berechnungsansätzen. In dieser Arbeit wurden effiziente Erweiterungen der Multilayer-Methode ONIOM und von Fragmentmethoden als Lösungsansätze für derartige Probleme entwickelt. Dabei wurde die Kombination von ONIOM und Fragmentmethoden im Rahmen der Multi-Centre Generalised ONIOM entwickelt sowie die eine Multilayer-Variante der Fragment Combinatio Ranges. Außerdem wurden Schemata für elektronische Einbettung derartiger Multilayer-Systeme entwickelt. Der zweite Teil der Arbeit beschreibt die Implementierung im Haskell-Programm "Spicy" und demonstriert Anwendungen derartiger Multiskalen-Methoden

    Publishing Sacrobosco’s De sphaera in Early Modern Europe

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    This open access volume focuses on the cultural background of the pivotal transformations of scientific knowledge in the early modern period. It investigates the rich edition history of Johannes de Sacrobosco’s Tractatus de sphaera, by far the most widely disseminated textbook on geocentric cosmology, from the unique standpoint of the many printers, publishers, and booksellers who steered this text from manuscript to print culture, and in doing so transformed it into an established platform of scientific learning. The corpus, constituted of 359 different editions featuring Sacrobosco’s treatise on cosmology and astronomy printed between 1472 and 1650, represents the scientific European shared knowledge concerned with the cosmological worldview of the early modern period until far after the publication of Copernicus’ De revolutionibus orbium coelestium in 1543. The contributions to this volume show how the academic book trade influenced the process of homogenization of scientific knowledge. They also describe the material infrastructure through which such knowledge was disseminated, and thus define the premises for the foundation of modern scientific communities

    Review of Particle Physics

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    The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances. The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume 2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented in the Listings. The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is available in print, as a web version optimized for use on phones, and as an Android app.United States Department of Energy (DOE) DE-AC02-05CH11231government of Japan (Ministry of Education, Culture, Sports, Science and Technology)Istituto Nazionale di Fisica Nucleare (INFN)Physical Society of Japan (JPS)European Laboratory for Particle Physics (CERN)United States Department of Energy (DOE

    Modeling high-entropy transition-metal alloys with alchemical compression

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    Alloys composed of several elements in roughly equimolar composition, often referred to as high-entropy alloys, have long been of interest for their thermodynamics and peculiar mechanical properties, and more recently for their potential application in catalysis. They are a considerable challenge to traditional atomistic modeling, and also to data-driven potentials that for the most part have memory footprint, computational effort and data requirements which scale poorly with the number of elements included. We apply a recently proposed scheme to compress chemical information in a lower-dimensional space, which reduces dramatically the cost of the model with negligible loss of accuracy, to build a potential that can describe 25 d-block transition metals. The model shows semi-quantitative accuracy for prototypical alloys, and is remarkably stable when extrapolating to structures outside its training set. We use this framework to study element segregation in a computational experiment that simulates an equimolar alloy of all 25 elements, mimicking the seminal experiments by Cantor et al., and use our observations on the short-range order relations between the elements to define a data-driven set of Hume-Rothery rules that can serve as guidance for alloy design. We conclude with a study of three prototypical alloys, CoCrFeMnNi, CoCrFeMoNi and IrPdPtRhRu, determining their stability and the short-range order behavior of their constituents

    Broadsheets

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    A landmark study of single-sheet publishing during the first two centuries after the invention of printing. Long disregarded as ephemera or cheap print, broadsheets emerge as both a crucial communication medium and an essential underpinning of the economics of the publishing industry.; Readership: Historians of the book, media history and news, bibliographers and librarians, and those interested in the politics, government, religion and literature of the early modern period

    Marine debris in the Bering Sea: combining historical records, toxicology, and local knowledge to assess impacts and identify solutions

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    Dissertation (Ph.D.) University of Alaska Fairbanks, 2022Marine debris, particularly plastic marine debris, has numerous impacts on the environment, wildlife, and human communities. This research examines dimensions of marine debris in the Bering Sea and Aleutian Islands, Alaska, including impacts of marine debris pollution on wildlife and the environment; the history of marine debris research, monitoring, and cleanup activities; and community perspectives on local to global solutions. The first chapter of this dissertation is an integrative literature review to better understand the current status of marine debris knowledge in the Bering Sea region and identify critical knowledge gaps. We synthesized the depth and breadth of research, monitoring, and cleanup activities to better understand the sources, prevalence, and impacts of marine debris on wildlife and coastal communities. Our review revealed several knowledge gaps, including two that were a focus of the final chapters of the dissertation: measuring the extent of plastic-associated contaminants in the Bering Sea and capturing community perspectives and concerns about marine debris in the Bering Sea. The second chapter examined variation in phthalates, a class of plastic-associated chemicals, in Aleutian Islands seabirds, to refine hypotheses regarding ecological and environmental factors that affect phthalate exposure in marine wildlife. We quantified phthalates in seabirds collected across >1700 km of the Aleutian Islands, Alaska, and measured six phthalate congeners in seabirds representing ten species and four feeding guilds. Phthalates were detected in 100% of specimens (n = 115) but varied among individuals (range 3.64 - 539.64 ng/g). Total phthalates did not vary geographically, but differed among feeding guilds, with significantly higher concentrations in diving plankton-feeders compared to others. Our findings suggest feeding behavior could influence exposure risk for seabirds and lend further evidence to the ubiquity of plastic pollutants in marine ecosystems. The final chapter of the dissertation explored perspectives and concerns of St. Paul Island community members regarding marine debris and plastic pollution. This component of the research aimed to catalyze the inclusion of local knowledge in marine debris solutions for St. Paul Island, Alaska, by documenting community members' perceptions of marine debris, including its origin, impacts, and proposed solutions. We interviewed thirty-six St. Paul Island community members from 2017 to 2020 about the types, amount, distribution, and impacts of marine debris they have observed on the island and its surrounding waters over recent decades. Research participants reported increases in plastic debris since the 1980s, particularly plastic bottles. Nearly 80% expressed concern about impacts to subsistence resources, including entanglement and ingestion of plastic particles by marine mammals and fishes. St. Paul Island community members' experiences highlight that solving the problem of marine debris cannot rely on local efforts alone but requires broader policies and mitigation strategies to address the sources of debris and advance environmental justice for coastal communities. Overall, this dissertation contributes an improved understanding of the social and ecological impacts of plastic pollution in the Bering Sea region and the potential science and policy solutions that can stem the tide of marine debris.Conoco PhillipsChapter 1: General introduction -- Chapter 2: A review of marine debris impacts and multi-scale solutions to plastic pollution in Bering Sea social-ecological systems -- Chapter 3: Plastic-derived contaminants in Aleutian Archipelago seabirds with varied foraging strategies -- Chapter 4: Including coastal community voices in the marine debris conversation: Perspectives from St. Paul Island, Alaska -- Chapter 5: General conclusion -- Appendices

    Cyanotoxins in Bloom

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    At present, cyanobacteria and their toxins (also known as cyanotoxins) constitute a major threat for freshwater resources worldwide. Cyanotoxin occurrence in water bodies around the globe is constantly increasing, whereas emerging, less studied or completely new variants and congeners of various chemical classes of cyanotoxins, as well as their degradation/transformation products are often detected. In addition to planctic cyanobacteria, benthic cyanobacteria, in many cases, appear to be important toxin producers, although far less studied and more difficult to manage and control. This Special Issue highlights novel research results on the structural diversity of cyanotoxins from planktic and benthic cyanobacteria, as well as on their expanding global geographical spread in freshwaters
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