The explosion of the web and the abundance of linked data demand effective and efficient methods for storage, management, and querying. Apache Spark is one of the most widely used engines for big data processing, with more and more systems adopting it for efficient query answering. Existing approaches exploiting Spark for querying RDF data, adopt partitioning techniques for reducing the data that need to be accessed in order to improve efficiency. However, simplistic data partitioning fails, on one hand, to minimize data access and on the other hand to group data usually queried together. This is translated into limited improvement in terms of efficiency in query answering. In this paper, we present DIAERESIS, a novel platform that accepts as input an RDF dataset and effectively partitions it, minimizing data access and improving query answering efficiency. To achieve this, DIAERESIS first identifies the top-k most important schema nodes, i.e., the most important classes, as centroids and distributes the other schema nodes to the centroid they mostly depend on. Then, it allocates the corresponding instance nodes to the schema nodes they are instantiated under. Our algorithm enables fine-tuning of data distribution, significantly reducing data access for query answering. We experimentally evaluate our approach using both synthetic and real workloads, strictly dominating existing state-of-the-art, showing that we improve query answering in several cases by orders of magnitude.

Work itself and occupational health and safety (OHS) have evolved through industrial revolutions and will also continue to evolve in the future. The aim of this qualitative literature review was to examine how the scientific discussion on new and emerging risks (NERs) related to OHS has evolved in recent decades in developed and newly industrialized countries. A search of the Scopus database yielded 34 articles published before 2000 and from 2020 onwards. A review of the articles identified NERs themes related to changes in work patterns, changing workforce and growth in some sectors, climate change, new materials or increased use of materials, new technology and technological development, and viruses. In both article collection periods, possible adverse OHS effects discussed included musculoskeletal disorders, exposure to toxic agents, chemical compounds and hazardous materials, increased stress, increased likelihood of errors and accidents, psychosocial problems, mental fatigue, and increases in work-related illnesses and accidents. The articles published during both periods discussed similar themes. The main differences were regarding specific time-related cases, such as climate change and COVID-19. Based on the findings of this review, points to consider in OHS management and future studies are discussed.

Light with a complex structure has become a powerful tool in many studies in classical and quantum optics. Here, we introduce a visual representation of light that is structured simultaneously in space, frequency, and polarization in the form of a higher-order Poincaré sphere and describe interesting links to its fundamental counterpart. We leverage the description to show and experimentally generate light possessing all possible polarization states across its spatiospectral shape, which we term spatiospectral Poincaré beams. By extending the powerful description of higher-order Poincaré spheres to the spatiospectral domain, our work will help to gain a deeper understanding and to develop beneficial applications of structured light. Published by the American Physical Society 2024

Abstract Most linguistic studies of political speaking in the field of critical discourse analysis tend to focus on speeches delivered by prominent politicians either in a domestic party-political setting or in the international arena. Less attention has been afforded to speeches by civil rights activists and campaigners for other progressive causes. To fill this gap, the present paper focuses on political speaking occurring outside of the party-political setting. The data comprises 120 American activist speeches from the years 1808–2016. The analysis focuses on the construction of ingroups and outgroups, and whether the use of personal pronouns is affected by the type of audience. The frequency trends bring forth new information about the referential complexity of pronouns within individual speeches.