156,485 research outputs found
An MPEG-7 scheme for semantic content modelling and filtering of digital video
Abstract Part 5 of the MPEG-7 standard specifies Multimedia Description Schemes (MDS); that is, the format multimedia content models should conform to in order to ensure interoperability across multiple platforms and applications. However, the standard does not specify how the content or the associated model may be filtered. This paper proposes an MPEG-7 scheme which can be deployed for digital video content modelling and filtering. The proposed scheme, COSMOS-7, produces rich and multi-faceted semantic content models and supports a content-based filtering approach that only analyses content relating directly to the preferred content requirements of the user. We present details of the scheme, front-end systems used for content modelling and filtering and experiences with a number of users
Inverse meta-modelling to estimate soil available water capacity at high spatial resolution across a farm
Geo-referenced information on crop production that is both spatially- and temporally-dense would be useful for management in precision agriculture (PA). Crop yield monitors provide spatially but not temporally dense information. Crop growth simulation modelling can provide temporal density, but traditionally fail on the spatial issue. The research described was motivated by the challenge of satisfying both the spatial and temporal data needs of PA. The methods presented depart from current crop modelling within PA by introducing meta-modelling in combination with inverse modelling to estimate site-specific soil properties. The soil properties are used to predict spatially- and temporally-dense crop yields. An inverse meta-model was derived from the agricultural production simulator (APSIM) using neural networks to estimate soil available water capacity (AWC) from available yield data. Maps of AWC with a resolution of 10 m were produced across a dryland grain farm in Australia. For certain years and fields, the estimates were useful for yield prediction with APSIM and multiple regression, whereas for others the results were disappointing. The estimates contain âimplicit informationâ about climate interactions with soil, crop and landscape that needs to be identified. Improvement of the meta-model with more AWC scenarios, more years of yield data, inclusion of additional variables and accounting for uncertainty are discussed. We concluded that it is worthwhile to pursue this approach as an efficient way of extracting soil physical information that exists within crop yield maps to create spatially- and temporally-dense dataset
Parsimonious Catchment and River Flow Modelling
It is increasingly the case that models are being developed as âevolvingâ products rather than\ud
one-off application tools, such that auditable modelling versus ad hoc treatment of models becomes a\ud
pivotal issue. Auditable modelling is particularly vital to âparsimonious modellingâ aimed at meeting\ud
specific modelling requirements. This paper outlines various contributory factors and aims to seed\ud
proactively a research topic by inextricably linking value/risk management to parsimonious modelling.\ud
Value management in modelling may be implemented in terms of incorporating âenough detailâ into a\ud
model so that the synergy among the constituent units of the model captures that of the real system. It is a\ud
problem of diminishing returns, since further reductions in the constituent units will create an\ud
unacceptable difference between the model and the real system; conversely, any further detail will add to\ud
the cost of modelling without returning any significant benefit. The paper also defines risk management\ud
in relation to modelling. It presents a qualitative framework for value/risk management towards\ud
parsimonious modelling by the categorisation of âmodelling techniquesâ in terms of âcontrol volume.
COSMOS-7: Video-oriented MPEG-7 scheme for modelling and filtering of semantic content
MPEG-7 prescribes a format for semantic content models for multimedia to ensure interoperability across a multitude of platforms and application domains. However, the standard leaves it open as to how the models should be used and how their content should be filtered. Filtering is a technique used to retrieve only content relevant to user requirements, thereby reducing the necessary content-sifting effort of the user. This paper proposes an MPEG-7 scheme that can be deployed for semantic content modelling and filtering of digital video. The proposed scheme, COSMOS-7, produces rich and multi-faceted semantic content models and supports a content-based filtering approach that only analyses content relating directly to the preferred content requirements of the user
Mesoscale mapping of sediment source hotspots for dam sediment management in data-sparse semi-arid catchments
Land degradation and water availability in semi-arid regions are interdependent challenges for management that are influenced by climatic and anthropogenic changes. Erosion and high sediment loads in rivers cause reservoir siltation and decrease storage capacity, which pose risk on water security for citizens, agriculture, and industry. In regions where resources for management are limited, identifying spatial-temporal variability of sediment sources is crucial to decrease siltation. Despite widespread availability of rigorous methods, approaches simplifying spatial and temporal variability of erosion are often inappropriately applied to very data sparse semi-arid regions. In this work, we review existing approaches for mapping erosional hotspots, and provide an example of spatial-temporal mapping approach in two case study regions. The barriers limiting data availability and their effects on erosion mapping methods, their validation, and resulting prioritization of leverage management areas are discussed.BMBF, 02WGR1421A-I, GROW - Verbundprojekt SaWaM: Saisonales Wasserressourcen-Management in Trockenregionen: Praxistransfer regionalisierter globaler Informationen, Teilprojekt 1DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische UniversitÀt Berli
Visualizing the dynamics of London's bicycle hire scheme
Visualizing ïŹows between origins and destinations can be straightforward when dealing with small numbers of journeys or simple geographies. Representing ïŹows as lines embedded in geographic space has commonly been used to map transport ïŹows, especially when geographic patterns are important as they are when characterising cities or managing transportation. However, for larger numbers of ïŹows, this approach requires careful design to avoid problems of occlusion, salience bias and information overload. Driven by the requirements identiïŹed by users and managers of the London Bicycle Hire scheme we present three methods of representation of bicycle hire use and travel patterns. Flow maps with curved ïŹow symbols are used to show overviews in ïŹow structures. Gridded views of docking station location that preserve geographic relationships are used to explore docking station status over space and time in a graphically eïŹcient manner. Origin-Destination maps that visualise the OD matrix directly while maintaining geographic context are used to provide visual details on demand. We use these approaches to identify changes in travel behaviour over space and time, to aid station rebalancing and to provide a framework for incorporating travel modelling and simulation
Mapping paddy rice in Asia: a multi-sensor, time-series approach.
Rice is the most important food crop in Asia and the mapping and monitoring of paddy
rice fields is an important task in the context of food security, food trade policy and
greenhouse gas emissions modelling. Two countries where rice is of special
significance are China, the largest producer and importer of rice, and Vietnam, where
rice exports contribute a fifth to the GDP. Both countries are facing increasing pressure
in terms of food security due to population and economic growth while agricultural
areas are confronted with urban encroachment and the limits of yield increase.
Despite the importance of knowledge about rice production the countries official land
cover products and rice production statistics are of varying quality and sometimes even
contradict each other. Available remote sensing studies focused either on time-series
analysis from optical sensors or from Synthetic Aperture Radar (SAR) sensors â the
studies using optical sensors faced problems due to either the spatial or temporal
resolution and the persistent cloud cover while SAR studies found the limited data
availability and large image size to be the biggest drawbacks. We try to address these
issues by proposing a paddy rice mapping approach that combines medium spatial
resolution, temporally dense time-series from the optical MODIS sensors and high
spatial resolution time-series from the recently launched Sentinel-1 SAR sensor.
We used the 250m resolution MOD13Q1 and MYD13Q1 products as a basis for our
medium resolution rice map. Prevalent cloud cover introduces noise into these timeseries
which we reduced by applying a Savitzky-Golay filter. We then derived a number
of time-series temporal and phenological metrics for multiple years and classified rice
areas with One Class Support Vector Machines. In a next step we used this medium
resolution rice map to mask Sentinel-1 Interferometric Wide Swath images and create
SAR time-series from which we again derived temporal and phenological metrics and
classified rice areas with machine learning algorithms to arrive at a 10m resolution rice
map.
This method allows concurrent, accurate and high resolution mapping of paddy rice
areas from freely available data with limited requirements towards processing
infrastructure and can be used as a basis for greenhouse gas and crop modelling as
well as providing viable information for decision makers regarding food security, food
trade, bioeconomy and mitigation after crop failure. Results of our paddy rice
classification will be presented for selected study sites in China and Vietnam
Big data analytics:Computational intelligence techniques and application areas
Big Data has significant impact in developing functional smart cities and supporting modern societies. In this paper, we investigate the importance of Big Data in modern life and economy, and discuss challenges arising from Big Data utilization. Different computational intelligence techniques have been considered as tools for Big Data analytics. We also explore the powerful combination of Big Data and Computational Intelligence (CI) and identify a number of areas, where novel applications in real world smart city problems can be developed by utilizing these powerful tools and techniques. We present a case study for intelligent transportation in the context of a smart city, and a novel data modelling methodology based on a biologically inspired universal generative modelling approach called Hierarchical Spatial-Temporal State Machine (HSTSM). We further discuss various implications of policy, protection, valuation and commercialization related to Big Data, its applications and deployment
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