171 research outputs found

    Taming Instabilities in Power Grid Networks by Decentralized Control

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    Renewables will soon dominate energy production in our electric power system. And yet, how to integrate renewable energy into the grid and the market is still a subject of major debate. Decentral Smart Grid Control (DSGC) was recently proposed as a robust and decentralized approach to balance supply and demand and to guarantee a grid operation that is both economically and dynamically feasible. Here, we analyze the impact of network topology by assessing the stability of essential network motifs using both linear stability analysis and basin volume for delay systems. Our results indicate that if frequency measurements are averaged over sufficiently large time intervals, DSGC enhances the stability of extended power grid systems. We further investigate whether DSGC supports centralized and/or decentralized power production and find it to be applicable to both. However, our results on cycle-like systems suggest that DSGC favors systems with decentralized production. Here, lower line capacities and lower averaging times are required compared to those with centralized production.Comment: 21 pages, 6 figures This is a pre-print of a manuscript submitted to The European Physical Journal. The final publication is available at Springer via http://dx.doi.org/10.1140/epjst/e2015-50136-

    Enriching Knowledge Bases with Counting Quantifiers

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    Information extraction traditionally focuses on extracting relations between identifiable entities, such as . Yet, texts often also contain Counting information, stating that a subject is in a specific relation with a number of objects, without mentioning the objects themselves, for example, "California is divided into 58 counties". Such counting quantifiers can help in a variety of tasks such as query answering or knowledge base curation, but are neglected by prior work. This paper develops the first full-fledged system for extracting counting information from text, called CINEX. We employ distant supervision using fact counts from a knowledge base as training seeds, and develop novel techniques for dealing with several challenges: (i) non-maximal training seeds due to the incompleteness of knowledge bases, (ii) sparse and skewed observations in text sources, and (iii) high diversity of linguistic patterns. Experiments with five human-evaluated relations show that CINEX can achieve 60% average precision for extracting counting information. In a large-scale experiment, we demonstrate the potential for knowledge base enrichment by applying CINEX to 2,474 frequent relations in Wikidata. CINEX can assert the existence of 2.5M facts for 110 distinct relations, which is 28% more than the existing Wikidata facts for these relations.Comment: 16 pages, The 17th International Semantic Web Conference (ISWC 2018

    Use of tobacco, nicotine and cannabis products among students in Switzerland.

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    INTRODUCTION Most people who smoke cigarettes begin in their teens and teens may also be attracted to new tobacco, nicotine, and cannabis products. We describe use prevalence among upper-secondary school students in Switzerland, including daily use, of tobacco, nicotine, and cannabis products. METHODS We invited secondary school students (age 15 to 21) in two Swiss cantons to take an online survey between October 2021 and February 2022. The survey collected demographic information and asked how frequently they used tobacco products (cigarettes in commercial packages, self-rolled cigarettes, hookahs, pipes, cigars and cigarillos, tobacco heating systems, snus, snuff), non-tobacco nicotine products (nicotine pouches, e-cigarettes with and without nicotine), and cannabis products (smoking with and without tobacco, cannabis vaping). Answers were scored on a Likert scale (no use in past month, less than weekly, weekly but not daily, daily use, prefer not to say), then tabulated and reported as descriptive statistics. RESULTS Of 32,614 students in the schools we contacted, 9,515 (29.2%) completed the survey; 49.5% identified as female and 48.4% as male; 9.5% were under 16, 47% were 16-17, 27.5% were 18-19, and 16% were over 19. Reported daily use was most frequent for tobacco cigarettes in commercial packages (14.2%), snus (4.1%) and cannabis smoking with tobacco (3.6%). Most participants (54.8%) reported they had used at least one product at least once within the last month. CONCLUSION Students who used a product were most likely to smoke cigarettes, but many regularly used new tobacco, nicotine and cannabis products, though use frequency varies

    Effects of Clinically Used Antioxidants in Experimental Pneumococcal Meningitis

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    Reactive oxygen intermediates mediate brain injury in bacterial meningitis. Several anti-oxidant drugs are clinically available, including N-acetylcysteine (NAC), deferoxamine (DFO), and trylizad-mesylate (TLM). The present study evaluated whether these antioxidants are beneficial in a model of pneumococcal meningitis. Eleven-day-old rats were infected intracisternally with Streptococcus pneumoniae and randomized to intraperitoneal treatment every 8 h with NAC (200 mg/kg), DFO (100 mg/kg), TLM (10 mg/kg), or saline (250 μL). TLM-treated animals showed a significantly reduced mortality compared with controls (P < .03). Meningitis led to extensive cortical injury at 22 ± 2.2 h after infection (median, 14.6% of cortex; range, 0-61.1%). Injury was significantly (P < .01) reduced to 1.1% (range, 0-34.6%) by NAC, to 2.3% (range, 0-19.6%) by DFO, and to 0.2% (range, 0-36.9%) by TLM (the difference was not significant among the 3 groups). None of the drugs reduced hippocampal injury. Thus, several clinically used antioxidants reduced cortical injury in experimental pneumococcal meningiti

    Use of tobacco, nicotine and cannabis products among students in Switzerland

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    IntroductionMost people who smoke cigarettes begin in their teens and teens may also be attracted to new tobacco, nicotine, and cannabis products. We describe use prevalence among upper-secondary school students in Switzerland, including daily use, of tobacco, nicotine, and cannabis products.MethodsWe invited secondary school students (age 15 to 21) in two Swiss cantons to take an online survey between October 2021 and February 2022. The survey collected demographic information and asked how frequently they used tobacco products (cigarettes in commercial packages, self-rolled cigarettes, hookahs, pipes, cigars and cigarillos, tobacco heating systems, snus, snuff), non-tobacco nicotine products (nicotine pouches, e-cigarettes with and without nicotine), and cannabis products (smoking with and without tobacco, cannabis vaping). Answers were scored on a Likert scale (no use in past month, less than weekly, weekly but not daily, daily use, prefer not to say), then tabulated and reported as descriptive statistics.ResultsOf 32,614 students in the schools we contacted, 9,515 (29.2%) completed the survey; 49.5% identified as female and 48.4% as male; 9.5% were under 16, 47% were 16–17, 27.5% were 18–19, and 16% were over 19. Reported daily use was most frequent for tobacco cigarettes in commercial packages (14.2%), snus (4.1%) and cannabis smoking with tobacco (3.6%). Most participants (54.8%) reported they had used at least one product at least once within the last month.ConclusionStudents who used a product were most likely to smoke cigarettes, but many regularly used new tobacco, nicotine and cannabis products, though use frequency varies

    Climate change literacy and migration potential: micro-level evidence from Africa

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    While a growing literature studies the effects of climate change on international migration, still only relatively little is known about the individual mechanisms linking migration decisions to climate change. We argue that climate change literacy (i.e., knowledge about climate change) is a major determinant of why some individuals consider migrating to other countries in response to climate change effects. In particular, climate change literacy helps individuals translate their perceptions of temperature changes into an understanding of these changes’ irreversible long-term consequences. We test this hypothesis using highly accurate geo-coded data for 37,000 individuals across 30 African countries. We show that climate change indeed leads to stronger migration intentions among climate literates only. Furthermore, we show that climate change only increases migration intentions among climate literates when it is approximated by long-run increases in local temperatures, but not when operationalized as changing heat wave or precipitation patterns. Further analyses show that climate literates are more likely to live in urban areas, have a higher news consumption, are highly educated, and have demanding occupations. Consequently, climate change may further deprive affected countries of valuable talent

    Cannabis Consumers' View of Regulated Access to Recreational Cannabis: A Multisite Survey in Switzerland.

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    INTRODUCTION There is considerable effort in legalizing recreational use of cannabis globally. The successful implementation of a program of regulated access to recreational cannabis (PRAC) depends on the consumers' engagement. The aim of this study was to examine the acceptability of twelve different regulatory aspects by cannabis users including those obtaining cannabis from the illicit market and vulnerable populations such as young adults and problematic users. METHODS The current study is a multisite online survey conducted in Switzerland. A total of 3,132 adult Swiss residents who consumed cannabis within the previous 30 days represented the studied population. Mean age was 30.5 years, 80.5% were men, and 64.2% of the participants stated that they always or often obtain cannabis from the illicit market. We described consumers' acceptability of twelve regulatory aspects concerning THC content control, disclosure of sensitive personal data, security aspects, and follow-up procedures by applying descriptive statistics and multiple regression models. RESULTS THC content regulation showed most discrepancy with 89.4% of the participants stating to engage in a PRAC if five different THC contents were available as compared to 54% if only 12% THC was available. The least accepted regulatory aspect was disposal of contact details with an acceptability rate of 18.1%. Consumers mainly obtaining cannabis from the illicit market, young adults, and problematic users showed similar acceptability patterns. Participants obtaining cannabis from the illicit market were more likely to engage in a PRAC if five different THC contents were available as compared to participants obtaining cannabis from other sources (OR 1.94, 95% CI: 1.53-2.46). CONCLUSION A carefully designed PRAC that takes into account the consumers' perspective is likely to transfer them to the regulated market and to engage vulnerable populations. We cannot recommend the distribution of cannabis with only 12% THC content as this is unlikely to engage the target population

    Enhanced findability and reusability of Engineering Data by Contextual Metadata

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    Complex research problems are increasingly addressed by interdisciplinary, collaborate research projects generating large amounts of heterogeneous amounts of data. The overarching processing, analysis and availability of data are critical success factors for these research efforts. Data repositories enable long term availability of such data for the scientific community. The findability and therefore reusability strongly builds on comprehensive annotations of datasets stored in repositories. Often generic metadata schema are used to annotate data. In this publication we describe the implementation of discipline specific metadata into a data repository to provide more contextual information about data. To avoid extra workload for researchers to provide such metadata a workflow with standardised data templates for automated metadata extraction during the ingest process has been developed. The enriched metadata are in the following used in the development of two repository plugins for data comparison and data visualisation. The added values of discipline-specific annotations and derived search features to support matching and reusable data is then demonstrated by use cases of two Collaborative Research Centres (CRC 1368 and CRC 1153)
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