528 research outputs found

    Auxiliary Signal-Based Distance Protection in Inverter-Dominated Power Systems

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    Power system protection schemes today rely on currents rising by several orders of magnitude when faults occur. In inverter-dominated power systems, a fault current might be just a few percent larger than normal, making fault detection more difficult. One solution is for the inverter to slightly perturb its output current and/or voltage, i.e., to inject an auxiliary signal, so as to make the system's behavior under faults easier to distinguish from normal. In this paper, we optimize auxiliary signals for fault detection with distance relays. We begin with a standard auxiliary signal design problem for generic static systems. We use duality to reformulate the problem as a bilinear program, which we solve using the convex-concave procedure. We implement the framework in an example based on distance protection, in which the auxiliary signal is negative sequence current

    “Birthday-Banding” as a Strategy to Moderate the Relative Age Effect: A Case Study Into the England Squash Talent Pathway

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    The relative age effect (RAE) is almost pervasive throughout youth sports, whereby relatively older athletes are consistently overrepresented compared to their relatively younger peers. Although researchers regularly cite the need for sports programs to incorporate strategies to moderate the RAE, organizational structures often continue to adopt a one-dimensional (bi)annual-age group approach. In an effort to combat this issue, England Squash implemented a “birthday-banding” strategy in its talent pathway, whereby young athletes move up to their next age group on their birthday, with the aim to remove particular selection time points and fixed chronological bandings. Thus, the purpose of this study was to examine the potential effects of the birthday-banding strategy on birth quarter (BQ) distributions throughout the England Squash talent pathway. Three mixed-gender groups were populated and analyzed: (a) ASPIRE athletes (n = 250), (b) Development and Potential athletes (n = 52), and (c) Senior team and Academy athletes (n = 26). Chi-square analysis and odds ratios were used to test BQ distributions against national norms and between quartiles, respectively. Results reveal no significant difference between BQ distributions within all three groups (P > 0.05). In contrast to most studies examining the RAE within athlete development settings, there appears to be no RAE throughout the England Squash talent pathway. These findings suggest that the birthday-banding strategy may be a useful tool to moderate RAE in youth sports

    DNA loops generate intracentromere tension in mitosis

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    The centromere is the DNA locus that dictates kinetochore formation and is visibly apparent as heterochromatin that bridges sister kinetochores in metaphase. Sister centromeres are compacted and held together by cohesin, condensin, and topoisomerase-mediated entanglements until all sister chromosomes bi-orient along the spindle apparatus. The establishment of tension between sister chromatids is essential for quenching a checkpoint kinase signal generated from kinetochores lacking microtubule attachment or tension. How the centromere chromatin spring is organized and functions as a tensiometer is largely unexplored. We have discovered that centromere chromatin loops generate an extensional/poleward force sufficient to release nucleosomes proximal to the spindle axis. This study describes how the physical consequences of DNA looping directly underlie the biological mechanism for sister centromere separation and the spring-like properties of the centromere in mitosis

    Best Practices for Publishing, Retrieving, and Using Spatial Data on the Web

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    Data owners are creating an ever richer set of information resources online, and these are being used for more and more applications. With the rapid growth of connected embedded devices, GPS-enabled mobile devices, and various organizations that publish their location-based data (i.e., weather and traffic services), maps and geographical and spatial information (i.e., GIS and open maps), spatial data on the Web is becoming ubiquitous and voluminous. However, the heterogeneity of the available spatial data, as well as some challenges related to spatial data in particular make it difficult for data users, web applications and services to discover, interpret and use the information in large and distributed web systems. This paper summarizes some of the efforts that have been undertaken in the joint W3C/OGC Working Group on Spatial Data on the Web, in particular the effort to describe the best practices for publishing spatial data on the Web. This paper presents the set of principles that guide the selection of these best practices, describes best practices that are employed to enable publishing, discovery and retrieving (querying) this type of data on the Web, and identifies some areas where a best practice has not yet emerged

    Los lenguajes controlados y la documentación técnica : mejorando la traducibilidad

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    Los lenguajes controlados pueden suponer una estrategia efectiva para mejorar los procesos de traducción, modificando el texto origen para que se adapte a una serie de reglas que mejoran su traducibilidad. El artículo analiza el concepto de lenguaje controlado y revisa las diferentes áreas de control y su tipología, para después realizar un breve repaso al origen y evolución de estos si stemas lingüísticos. A continuación explora qué papel representan los lenguajes controlados en el proceso de redacción y traducción de documentación técnica. Por último, se centra en la relación entre lenguajes controlados y traducción y, más en concreto, la traducción automática, haciendo especial hincapié en las reglas más efectivas para la mejora de la traducibilidad.Els llenguatges controlats poden suposar una estratègia efectiva per a millorar els processos de traducció, modificant el text origen perquè s'adapte a una sèrie de regles que milloren la seua traduïbilitat. L'article analitza el concepte de llenguatge controlat i revisa les diferents àrees de control i la seua tipologia, per a després realitzar un breu repàs a l'origen i evolució d'estos sistemes lingüístics. A continuació explora quin paper representen els llenguatges controlats en el procés de redacció i traducció de documentació tècnica. Finalment, es centra en la relació entre llenguatges controlats i traducció i, més concretament, traducció autom àtica, fent especial insistència en les regles més efectives per a la millora de la traduïbilitat.Controlled languages can be an effective strategy to improve translation processes, pre-editing the source text to conform to a set of rules to improve its translatability. This article analyses the concept of controlled language and reviews the different control areas and their typology. Further, it reviews the origin and evolution of these linguistic systems and explores the role controlled languages play in the process of writing and translating technical documentation. Finally, it focuses on the relationship between controlled language and translation and, more specifically, machine translation, with particular emphasis on the rules aimed at improving translatability

    POTs: Protective Optimization Technologies

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    Algorithmic fairness aims to address the economic, moral, social, and political impact that digital systems have on populations through solutions that can be applied by service providers. Fairness frameworks do so, in part, by mapping these problems to a narrow definition and assuming the service providers can be trusted to deploy countermeasures. Not surprisingly, these decisions limit fairness frameworks' ability to capture a variety of harms caused by systems. We characterize fairness limitations using concepts from requirements engineering and from social sciences. We show that the focus on algorithms' inputs and outputs misses harms that arise from systems interacting with the world; that the focus on bias and discrimination omits broader harms on populations and their environments; and that relying on service providers excludes scenarios where they are not cooperative or intentionally adversarial. We propose Protective Optimization Technologies (POTs). POTs provide means for affected parties to address the negative impacts of systems in the environment, expanding avenues for political contestation. POTs intervene from outside the system, do not require service providers to cooperate, and can serve to correct, shift, or expose harms that systems impose on populations and their environments. We illustrate the potential and limitations of POTs in two case studies: countering road congestion caused by traffic-beating applications, and recalibrating credit scoring for loan applicants.Comment: Appears in Conference on Fairness, Accountability, and Transparency (FAT* 2020). Bogdan Kulynych and Rebekah Overdorf contributed equally to this work. Version v1/v2 by Seda G\"urses, Rebekah Overdorf, and Ero Balsa was presented at HotPETS 2018 and at PiMLAI 201

    Chronic probiotic supplementation with or without glutamine does not influence the eHsp72 response to a multi-day ultra-endurance exercise event

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    Probiotic and glutamine supplementation increases tissue Hsp72, but their influence on extracellular Hsp72 (eHsp72) has not been investigated. The aim of this study was to investigate the effect of chronic probiotic supplementation, with or without glutamine, on eHsp72 concentration before and after an ultramarathon. Thirty-two participants were split into three independent groups, where they ingested probiotic capsules (PRO, n = 11), probiotic + glutamine powder (PGLn, n = 10) or no supplementation (CON, n = 11), over a 12-week period prior to commencement of the Marathon des Sables (MDS). eHsp72 concentration in the plasma was measured at baseline, 7 days pre-race, 6-8 hours post-race, and 7 days post-race. The MDS increased eHsp72 concentrations by 124% (F1,3 = 22.716, p 0.05). In conclusion, the MDS caused a substantial increase in eHsp72 concentration indicating high levels of systemic stress. However, chronic PRO or PGLn supplementation did not effect eHsp72 compared to control pre- or post-MDS. Given the role of eHsp72 in immune activation, the commercially available supplements used in this study are unlikely to influence this cascade
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