2,326 research outputs found

    Integrated opto-chemical sensors

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    Integrated opto-chemical sensors have promising prospects, for example by having the potential to be realized as very sensitive small monolithic smart multisensor systems with a digital signal output. Here the main accent will be laid on the optical principles underlying chemo-optical waveguiding sensors, focusing on linear evanescent field sensors. Sensing principles and systems based on interferometry, surface plasmon resonance and luminescence quenching will be treated in more detail. Materials and technologies applied to integrated optic sensors are mentioned

    Review: optical fiber sensors for civil engineering applications

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    Optical fiber sensor (OFS) technologies have developed rapidly over the last few decades, and various types of OFS have found practical applications in the field of civil engineering. In this paper, which is resulting from the work of the RILEM technical committee “Optical fiber sensors for civil engineering applications”, different kinds of sensing techniques, including change of light intensity, interferometry, fiber Bragg grating, adsorption measurement and distributed sensing, are briefly reviewed to introduce the basic sensing principles. Then, the applications of OFS in highway structures, building structures, geotechnical structures, pipelines as well as cables monitoring are described, with focus on sensor design, installation technique and sensor performance. It is believed that the State-of-the-Art review is helpful to engineers considering the use of OFS in their projects, and can facilitate the wider application of OFS technologies in construction industry

    Humanitarian Demining: The Challenge for Robotic Research

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    Current methods for detecting and removing mines are dangerous, too costly, and, considering the number of abandoned mines, very slow. Mechanical systems are most frequently used to clear large areas polluted by mines. Mechanical systems usually consist of a tank that uses rollers to apply pressure to the ground, rotary flails that beat the ground, or a rake that unearths and presses the mines. The main drawback of purely mechanical demining is that no system can satisfy the desired 100% reliability of humanitarian demining. Consequently, all cleaned areas require manual verification. Thus, an urgent need exists to develop safe and efficient demining methods. This requirement represents a big challenge for robotic research. Research for detecting and localizing mines is still ongoing. In addition to known methods, new sophisticated sensing principles are under development. These sensing principles make it possible to detect and recognize mines as hidden objects. Several vehicles equipped with demining technology also are being produced

    Observability analysis and optimal sensor placement in stereo radar odometry

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    © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Localization is the key perceptual process closing the loop of autonomous navigation, allowing self-driving vehicles to operate in a deliberate way. To ensure robust localization, autonomous vehicles have to implement redundant estimation processes, ideally independent in terms of the underlying physics behind sensing principles. This paper presents a stereo radar odometry system, which can be used as such a redundant system, complementary to other odometry estimation processes, providing robustness for long-term operability. The presented work is novel with respect to previously published methods in that it contains: (i) a detailed formulation of the Doppler error and its associated uncertainty; (ii) an observability analysis that gives the minimal conditions to infer a 2D twist from radar readings; and (iii) a numerical analysis for optimal vehicle sensor placement. Experimental results are also detailed that validate the theoretical insights.Peer ReviewedPostprint (author's final draft

    Open data and Earth observations

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    Abstract Earth observations (EO) represent a growing and valuable resource for many scientific, research and practical applications carried out by users around the world. Access to EO data for some applications or activities, like climate change research or emergency response activities, becomes indispensable for their success. However, often EO data or products made of them are (or are claimed to be) subject to intellectual property law protection and are licensed under specific conditions regarding access and use. Restrictive conditions on data use can be prohibitive for further work with the data. Global Earth Observation System of Systems (GEOSS) is an initiative led by the Group on Earth Observations (GEO) with the aim to provide coordinated, comprehensive, and sustained EO and information for making informed decisions in various areas beneficial to societies, their functioning and development. It seeks to share data with users world-wide with the fewest possible restrictions on their use by implementing GEOSS Data Sharing Principles adopted by GEO. The Principles proclaim full and open exchange of data shared within GEOSS, while recognizing relevant international instruments and national policies and legislation through which restrictions on the use of data may be imposed. The proposed paper focuses on the issue of the legal-interoperability of data that are shared with varying restrictions on use with the aim to explore the options of making data interoperable. The paper analyses legal protection regimes and their norms applicable to EO data. Based on the findings, it highlights the existing public law statutory, regulatory, and policy approaches, as well as private law instruments, such as waivers, licenses and contracts, that may be used to place the datasets in the public domain, or otherwise make them publicly available for use and re-use without restrictions. It uses GEOSS and the particular characteristics of it as a system to identify the ways to reconcile the vast possibilities it provides through sharing of data from various sources and jurisdictions on the one hand, and the restrictions on the use of the shared resources on the other. On a more general level the paper seeks to draw attention to the obstacles and potential regulatory solutions for sharing factual or research data for the purposes that go beyond research and education

    Proximal Soil Sensing – A Contribution for Species Habitat Distribution Modelling of Earthworms in Agricultural Soils?

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    Earthworms are important for maintaining soil ecosystem functioning and serve as indicators of soil fertility. However, detection of earthworms is time-consuming, which hinders the assessment of earthworm abundances with high sampling density over entire fields. Recent developments of mobile terrestrial sensor platforms for proximal soil sensing (PSS) provided new tools for collecting dense spatial information of soils using various sensing principles. Yet, the potential of PSS for assessing earthworm habitats is largely unexplored. This study investigates whether PSS data contribute to the spatial prediction of earthworm abundances in species distribution models of agricultural soils

    A single-mask thermal displacement sensor in MEMS

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    Position sensing in MEMS is often based on the principle of varying capacitance [1]. Alternative position sensing principles include using integrated optical waveguides [2] or varying thermal conductance [3]. Lantz et al demonstrated a thermal displacement sensor achieving nanometre resolution on a 100mm range. However a multi-mask production process and manual assembly were needed to fabricate this displacement sensor. In this work we present a 1-DOF thermal displacement sensor integrated with an actuated stage, and its experimental characterization. The system was fabricated in the device layer of a silicon-on-\ud insulator (SOI) wafer using a single-mask process.\ud \u
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