28 research outputs found

    The Caltech CSN project collects sensor data from thousands of personal devices for realtime response to dangerous earthquakes

    Get PDF
    The proliferation of smartphones and other powerful sensor-equipped consumer devices enables a new class of Web application: community sense and response (CSR) systems, distinguished from standard Web applications by their use of community-owned commercial sensor hardware. Just as social networks connect and share human-generated content, CSR systems gather, share, and act on sensory data from users' Internet-enabled devices. Here, we discuss the Caltech Community Seismic Network (CSN) as a prototypical CSR system harnessing accelerometers in smartphones and consumer electronics, including the systems and algorithmic challenges of designing, building, and evaluating a scalable network for real-time awareness of dangerous earthquakes

    Designing and implementing a distributed earthquake early warning system for resilient communities: a PhD thesis

    Get PDF
    The present work aims to comprehensively contribute to the process, design, and technologies of Earthquake Early Warning (EEW). EEW systems aim to detect the earthquake immediately at the epicenter and relay the information in real-time to nearby areas, anticipating the arrival of the shake. These systems exploit the difference between the earthquake wave speed and the time needed to detect and send alerts. This Ph.D. thesis aims to improve the adoption, robustness, security, and scalability of Earthquake Early Warning systems using a decentralized approach to data processing and information exchange. The proposed architecture aims to have a more resilient detection, remove Single point of failure, higher efficiency, mitigate security vulnerabilities, and improve privacy regarding centralized EEW architectures. A prototype of the proposed architecture has been implemented using low-cost sensors and processing devices to quickly assess the ability to provide the expected information and guarantees. The capabilities of the proposed architecture are evaluated not only on the main EEW problem but also on the quick estimation of the epicentral area of an earthquake, and the results demonstrated that our proposal is capable of matching the performance of current centralized counterparts

    Community Sense and Response Systems: Your Phone as Quake Detector

    Get PDF
    The proliferation of smartphones and other powerful sensor-equipped consumer devices enables a new class of Web application: community sense and response (CSR) systems, distinguished from standard Web applications by their use of community-owned commercial sensor hardware. Just as social networks connect and share human-generated content, CSR systems gather, share, and act on sensory data from users' Internet-enabled devices. Here, we discuss the Caltech Community Seismic Network (CSN) as a prototypical CSR system harnessing accelerometers in smartphones and consumer electronics, including the systems and algorithmic challenges of designing, building, and evaluating a scalable network for real-time awareness of dangerous earthquakes

    Community Sense and Response Systems

    Get PDF
    The proliferation of smartphones and other internet-enabled, sensor-equipped consumer devices enables us to sense and act upon the physical environment in unprecedented ways. This thesis considers Community Sense-and-Response (CSR) systems, a new class of web application for acting on sensory data gathered from participants' personal smart devices. The thesis describes how rare events can be reliably detected using a decentralized anomaly detection architecture that performs client-side anomaly detection and server-side event detection. After analyzing this decentralized anomaly detection approach, the thesis describes how weak but spatially structured events can be detected, despite significant noise, when the events have a sparse representation in an alternative basis. Finally, the thesis describes how the statistical models needed for client-side anomaly detection may be learned efficiently, using limited space, via coresets. The Caltech Community Seismic Network (CSN) is a prototypical example of a CSR system that harnesses accelerometers in volunteers' smartphones and consumer electronics. Using CSN, this thesis presents the systems and algorithmic techniques to design, build and evaluate a scalable network for real-time awareness of spatial phenomena such as dangerous earthquakes.</p

    SEISMOLOGY AT SCHOOL IN NEPAL: BUILDING AN OPERATIONAL LOW-COST SEISMIC NETWORK TO ESTABLISH AN EDUCATIONAL SEISMOLOGY PROGRAM

    Get PDF

    Control and prevention of ice formation and accretion on heat exchangers for ventilation systems

    Get PDF

    Citizen Science: Reducing Risk and Building Resilience to Natural Hazards

    Get PDF
    Natural hazards are becoming increasingly frequent within the context of climate change—making reducing risk and building resilience against these hazards more crucial than ever. An emerging shift has been noted from broad-scale, top-down risk and resilience assessments toward more participatory, community-based, bottom-up approaches. Arguably, non-scientist local stakeholders have always played an important role in risk knowledge management and resilience building. Rapidly developing information and communication technologies such as the Internet, smartphones, and social media have already demonstrated their sizeable potential to make knowledge creation more multidirectional, decentralized, diverse, and inclusive (Paul et al., 2018). Combined with technologies for robust and low-cost sensor networks, various citizen science approaches have emerged recently (e.g., Haklay, 2012; Paul et al., 2018) as a promising direction in the provision of extensive, real-time information for risk management (as well as improving data provision in data-scarce regions). It can serve as a means of educating and empowering communities and stakeholders that are bypassed by more traditional knowledge generation processes. This Research Topic compiles 13 contributions that interrogate the manifold ways in which citizen science has been interpreted to reduce risk against hazards that are (i) water-related (i.e., floods, hurricanes, drought, landslides); (ii) deep-earth-related (i.e., earthquakes and volcanoes); and (iii) responding to global environmental change such as sea-level rise. We have sought to analyse the particular failures and successes of natural hazards-related citizen science projects: the objective is to obtain a clearer understanding of “best practice” in a citizen science context

    Addressing Geohazards Through Ocean Drilling

    Get PDF
    corecore