578 research outputs found

    Expressive Stream Reasoning with Laser

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    An increasing number of use cases require a timely extraction of non-trivial knowledge from semantically annotated data streams, especially on the Web and for the Internet of Things (IoT). Often, this extraction requires expressive reasoning, which is challenging to compute on large streams. We propose Laser, a new reasoner that supports a pragmatic, non-trivial fragment of the logic LARS which extends Answer Set Programming (ASP) for streams. At its core, Laser implements a novel evaluation procedure which annotates formulae to avoid the re-computation of duplicates at multiple time points. This procedure, combined with a judicious implementation of the LARS operators, is responsible for significantly better runtimes than the ones of other state-of-the-art systems like C-SPARQL and CQELS, or an implementation of LARS which runs on the ASP solver Clingo. This enables the application of expressive logic-based reasoning to large streams and opens the door to a wider range of stream reasoning use cases.Comment: 19 pages, 5 figures. Extended version of accepted paper at ISWC 201

    A general introduction to lithium-ion batteries: From the first concept to the top six commercials and beyond

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    The birth of lithium-ion batteries (LIBs) is not a breakthrough scientific discovery overnight but a successor and continuous development of scientists for a long time based on the previous generation of electrochemical batteries. The development of LIBs and succeeding generations of batteries, however, is highly hopeful given the broad commercialization of LIBs during the previous ten years. Intensified research is required to create next-generation LIBs with drastically better performance, including enhanced energy density, charging rate, lifespan, stability, and safety, in order to fulfill the rising demand for energy storage. Research into LIBs and next-generation is currently in an explosive phase with the goal of overcoming the significant challenge posed by conventional LIBs that can keep up with the rapidly evolving needs of the electronics, mechanical, and automation industries, particularly electric vehicles. In this case, this tutorial review might offer a broad overview of LIBs as well as an optimistic look toward the upcoming generation

    Some behaviours of strongest short-term coastal change induced by cross-shore wave energy flow and corresponding theoretical consideration

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    There is a number of famous theoretical and experimental works that oriented themselves to solve actual problem of coastal change, including the change of coastline, under versatile influence of oceanic wind waves. In this paper the author would like to give supplementally a few new behaviours of that phenomena observed along the coasts of Vietnam, such as coastal collapse & primitive on-the-spot accumulation, material hurl, etc. Most simple theoretical explanation of them grounding on the Newton's second law has been presented and as results of that there appeared such notion as indicator and criterion which could be used for demarcation of different behaviours in initial stage of general coastal changing processes

    Factors affecting student persistence at public research universities in Oklahoma

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    Prior studies have demonstrated that most college dropouts happen at the transition to the third semester of college. Using a state dataset that includes student data for the 2013-2014 time span in the state of Oklahoma, the researcher examined the validity of students' background characteristics, high school performance, and financial aid status in predicting first-year college performance and persistence beyond the second semester of college.Data from 116,991 degree-seeking first-year students enrolled at research universities in Oklahoma from fall 2013 to fall 2014 were entered in the SPSS software for data analyses, which include both multiple linear regression and multiple logistic regression.The researcher finds that students' enrollment status and federal Perkins loans do not yield strong predictions of how students will perform academically or whether they will return to the second year of college. For tuition waivers, the associations with college performance and persistence are stronger, but still not significant. In contrast, spring GPA, Oklahoma's Promise, high school grade point average, American College Testing scores, and gender are useful for predicting persistence to the third semester, and have a strong association with their college performance.These findings might reflect current efforts by the Federal Government, State agencies, institutions and schools to promote student success, help them pay college tuition, and increase students' pre-college performance

    Recent Advances in TiO2 Nanotube-Based Materials for Photocatalytic Applications Designed by Anodic Oxidation

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    This book chapter reports some spectacular and interesting 1D nanostructures of TiO2, which are grown by the anodic oxidation. Under suitable conditions, conventional one-step anodic oxidation is available to grow TiO2 nanotube arrays (TNAs) and TiO2 nanowires/nanotubes; meanwhile, two-step anodic oxidation allows fabricating some novel TNAs with spectacular morphologies such as highly ordered TNAs, bamboo-type TNAs, and lotus root-shaped TNAs. The formation mechanisms of these nanostructures during the anodic oxidation processes are elusive via studying effects of several key parameters such as oxidizing voltage, processing time, and electrolytes. In addition, the photocatalytic activity of the TNA-based nanomaterials is characterized by the degradation of pharmaceutical model, methylene blue, or the photoelectrochemical effect

    Building a P2P RDF Store for Edge Devices

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    The Semantic Web technologies have been used in the Internet of Things (IoT) to facilitate data interoperability and address data heterogeneity issues. The Resource Description Framework (RDF) model is employed in the integration of IoT data, with RDF engines serving as gateways for semantic integration. However, storing and querying RDF data obtained from distributed sources across a dynamic network of edge devices presents a challenging task. The distributed nature of the edge shares similarities with Peer-to-Peer (P2P) systems. These similarities include attributes like node heterogeneity, limited availability, and resources. The nodes primarily undertake tasks related to data storage and processing. Therefore, the P2P models appear to present an attractive approach for constructing distributed RDF stores. Based on P-Grid, a data indexing mechanism for load balancing and range query processing in P2P systems, this paper proposes a design for storing and sharing RDF data on P2P networks of low-cost edge devices. Our design aims to integrate both P-Grid and an edge-based RDF storage solution, RDF4Led for building an P2P RDF engine. This integration can maintain RDF data access and query processing while scaling with increasing data and network size. We demonstrated the scaling behavior of our implementation on a P2P network, involving up to 16 nodes of Raspberry Pi 4 devices.Comment: Accepted to IoT Conference 202

    Semantic Programming for Device-Edge-Cloud Continuum

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    This position paper presents ThothSP, a Semantic Programming framework with the aim of lowering the coding effort in building smart applications on the Device-Edge-Cloud continuum by leveraging semantic knowledge. It introduces a novel neural-symbolic stream fusion mechanism, which enables the specification of data fusion pipelines via declarative rules, with degrees of learnable probabilistic weights. Moreover, it includes an adaptive federator that allows the Thoth>runtime to be distributed across multiple compute nodes in a network, and to coordinate their resources to collaboratively process tasks by delegating partial workloads to their peers. To demonstrate ThothSP's capability, we report a case study on a distributed camera network to show ThothSP's behaviour against a traditional edge-cloud setup.Comment: arXiv admin note: text overlap with arXiv:2202.1395

    Forward Kinematics Based Prediction for Bending Motion of Soft Pneumatic Actuators with Various Air Chambers

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    This study proposes a forward kinematic model for soft actuators that utilize pneumatic control to predict their bending motion, which is simulated using Ansys software. Firstly, a bending motion test is conducted with a 2-air chamber actuator to derive an equation that establishes the relationship between the bending angle and input pressure. Next, a serial model for the overall soft actuator is developed using forward kinematics with the DH method. The angle variables in the soft actuator are then replaced with an equation that relates the deformed angle and compressed air. Finally, the proposed serial model is used to predict the bending motion of 4-air and 6-air chamber actuators, and the results are compared to simulations and real experiments. The comparison shows that the proposed model could accurately predict the bending motion of the real actuators within an acceptable tolerance of 10%
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