1,720,980 research outputs found
Data driven methods for real time flood, drought and water quality monitoring: applications for Internet of Water
No full textThe Internet of Water (IoW) is a large-scale permanent sensor network with 2500 small, energy-efficient wireless water quality sensors spread across Flanders, Belgium. This intelligent water management system will permanently monitor water quality and quantity in real time. Such a dense network of sensors with high temporal resolution (sub-hourly) will provide unprecedented volumes of data for drought, flood and pollution management, prediction and decisions. While traditional physical hydrological models are obvious choices for utilizing such a dataset, computational costs or limitations must be considered when working in real time decision making. In collaboration with the Flemish Institute for Technological Research (VITO) and the University of Hasselt, we present several data mining and machine learning initiatives which support the IoW. Examples include interpolating grab sample measurements to river stretches to monitor salinity intrusion. A shallow feed forward neural network is trained on historical grab samples using physical characteristics of the river stretches (i.e. soil properties, ocean connectivity). Such a system allows for salinity monitoring without complex convection-diffusion modeling, and for estimating salinity in areas with less monitoring stations. Another highlighted project is the coupling of neural network and data assimilation schemes for water quality forecasting. A long short-term memory recurrent neural network is trained on historical water quality parameters and remotely sensed spatially distributed weather data. Using forecasted weather data, a model estimate of water quality parameters are obtained from the neural network. A Newtonian nudging data assimilation scheme further corrects the forecast leveraging previous day observations, which can aid in the correction for non-point or non-weather driven pollution influences. Calculations are supported by an optimized database system developed by the University of Hasselt which further exploits data mining techniques to estimate water movement and timing through the Flanders river network system. As geospatial data increases exponentially in both temporal and spatial resolutions, scientists and water managers must consider the tradeoff between computational resources and physical model accuracy. These type of hybrid approaches allows for near real-time analysis without computational limitations and will further support research to make communities more climate resilient. Powered by TCPDF (www.tcpdf.org
Data Driven Methods for Real-Time Flood, Drought and Water Quality Monitoring: Applications for Internet of Water
No full textThe Internet of Water (IoW) is a large-scale permanent IoT sensor network with 2500 water quality sensors spread across Flanders, Belgium. This intelligent system will permanently monitor water quality and quantity in real-time. Such a dense network of sensors with high temporal resolution will provide unprecedented volumes of data for drought, flood and pollution management, prediction and decisions. Here we present several data mining and machine learning initiatives along with a database infrastructure which supports environmental modelling efforts and large scale monitoring networks like IoW. Examples include interpolating grab sample measurements to river stretches to monitor salinity intrusion. A shallow feed forward neural network is trained on historical grab samples using physical characteristics of the river stretches. Such a system allows for salinity monitoring without complex convection-diffusion modeling, and for estimating salinity in areas with less monitoring stations. Another highlighted project is the coupling of neural network and data assimilation schemes for water quality forecasting. A long short-term memory recurrent neural network is trained on historical water quality parameters and remotely sensed spatially distributed weather data. Using forecasted weather data, a model estimate of water quality parameters are obtained from the neural network. A Newtonian nudging data assimilation scheme further corrects the forecast leveraging previous day observations, which can aid in the correction for non-point or non-weather driven pollution influences. Calculations are supported by an optimized database system developed by the Hasselt University which further exploits data mining techniques to estimate water movement and timing through the Flanders river network system. As geospatial data increases exponentially in temporal and spatial resolutions, scientists and water managers must consider the tradeoff between computational resources and physical model accuracy. These type of hybrid approaches allows for near real-time analysis without computational limitations and will further support research to make communities more climate resilient
Data Driven Methods for Real-Time Flood, Drought and Water Quality Monitoring: Applications for Internet of Water
No full textThe Internet of Water (IoW) is a large-scale permanent IoT sensor network with 2500 water quality sensors spread across Flanders, Belgium. This intelligent system will permanently monitor water quality and quantity in real-time. Such a dense network of sensors with high temporal resolution will provide unprecedented volumes of data for drought, flood and pollution management, prediction and decisions. Here we present several data mining and machine learning initiatives along with a database infrastructure which supports environmental modelling efforts and large scale monitoring networks like IoW. Examples include interpolating grab sample measurements to river stretches to monitor salinity intrusion. A shallow feed forward neural network is trained on historical grab samples using physical characteristics of the river stretches. Such a system allows for salinity monitoring without complex convection-diffusion modeling, and for estimating salinity in areas with less monitoring stations. Another highlighted project is the coupling of neural network and data assimilation schemes for water quality forecasting. A long short-term memory recurrent neural network is trained on historical water quality parameters and remotely sensed spatially distributed weather data. Using forecasted weather data, a model estimate of water quality parameters are obtained from the neural network. A Newtonian nudging data assimilation scheme further corrects the forecast leveraging previous day observations, which can aid in the correction for non-point or non-weather driven pollution influences. Calculations are supported by an optimized database system developed by the Hasselt University which further exploits data mining techniques to estimate water movement and timing through the Flanders river network system. As geospatial data increases exponentially in temporal and spatial resolutions, scientists and water managers must consider the tradeoff between computational resources and physical model accuracy. These type of hybrid approaches allows for near real-time analysis without computational limitations and will further support research to make communities more climate resilient
Design of database systems for optimized spatio-temporal querying to facilitate monitoring, analysing and forecasting in the "Internet of Water"
No full textMonitoring, analysing and forecasting water-systems, such as rivers, lakes and seas, is an essential part of the tasks for an environmental agency or government. In the region of Flanders, in Belgium, different organisations have united to create the "Internet of Water" (IoW). During this project, 2500 wireless water-quality sensors will be deployed in rivers, canals and lakes all over Flanders. This network of sensors will support a more accurate management of water systems by feeding real-time data. Applications include monitoring real-time water-flows, automated warnings and notifications to appropriate organisations, tracing pollution and the prediction of salinisation. Despite the diversity of these applications, they mostly rely on a correct spatial representation and fast querying of the flow path: where does water flow to, where can the water come from, and when does the water pass at certain locations? In the specific case of Flanders, the human-influenced landscape provides additional complexity with rivers, channels, barriers and even cycles. Numerous models and systems exist that are able to answer the above questions, even very precisely, but they often lack the ability to produce the results quickly enough for real-time applicability that is required in the IoW. Moreover, the rigid data representation makes it impossible to integrate new data sources and data types, especially in the IoW, where the data originates from vastly different backgrounds. In this research, we focus on the performance of spatio-temporal queries taking into account the spatial configuration of a strongly human-influenced water system and the real-time acquisition and processing of sensor data. The use of graph-database systems is compared with relational-database systems to store topologies and execute recursive path-tracing queries. Not only storing and querying are taken into account, but also the creation and updating of the topologies are an essential part. Moreover, the advantages of a hybrid approach that integrates the graph-based databases for spatial topologies with relational databases for temporal and water-system attributes are investigated. The fast querying of both upstream and downstream flow-path information is of great use in various applications (e.g., pollution tracking, alerting, relating sensor signals, …). By adding a wrapper library and creating a standardised result graph representation, the complexity is abstracted away from the individual applications
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A database system for querying of river networks : facilitating monitoring and prediction applications
No full textAbstract: The increasing availability of real-time in situ measurements and remote sensing observations have the potential to contribute to the optimization of water resources management. Global challenges such as climate change, intensive agriculture and urbanization put a high pressure on our water resources. Due to recent innovations in measuring both water quantity and quality, river systems can now be monitored in real time at an unprecedented spatial and temporal scale. To interpret the sensor measurements and remote sensing observations additional data for example on: the location of the measurement, upstream and downstream catchment characteristics, horizontal ellipsis are required. In this paper, we present a data management system to support flow-path related functionality for decision making and prediction modelling. Adding meta data sets and facilitating (near) real-time processing of sensor data questions are key concepts for the systems. The potential of the database framework for hydrological applications is demonstrated using different applications for the river system of Flanders. In one, the database framework is used to simulate the daily discharge for each segment within a catchment using a simple data-driven approach. The presented system is useful for numerous applications including pollution tracking, alerting and inter-sensor validation in river systems, or related networks
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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