399 research outputs found
Visual Analysis of Spatio-Temporal Event Predictions: Investigating the Spread Dynamics of Invasive Species
Invasive species are a major cause of ecological damage and commercial
losses. A current problem spreading in North America and Europe is the vinegar
fly Drosophila suzukii. Unlike other Drosophila, it infests non-rotting and
healthy fruits and is therefore of concern to fruit growers, such as vintners.
Consequently, large amounts of data about infestations have been collected in
recent years. However, there is a lack of interactive methods to investigate
this data. We employ ensemble-based classification to predict areas susceptible
to infestation by D. suzukii and bring them into a spatio-temporal context
using maps and glyph-based visualizations. Following the information-seeking
mantra, we provide a visual analysis system Drosophigator for spatio-temporal
event prediction, enabling the investigation of the spread dynamics of invasive
species. We demonstrate the usefulness of this approach in two use cases
The Chemistry of Reticular Framework Nanoparticles: MOF, ZIF, and COF Materials
Nanoparticles have become a vital part of a vast number of established processes and products;they are used as catalysts, in cosmetics, and even by the pharmaceutical industry. Despite this, however, the reliable and reproducible production of functional nanoparticles for specific applications remains a great challenge. In this respect, reticular chemistry provides methods for connecting molecular building blocks to nanoparticles whose chemical composition, structure, porosity, and functionality can be controlled and tuned with atomic precision. Thus, reticular chemistry allows for the translation of the green chemistry principle of atom economy to functional nanomaterials, giving rise to the multifunctional efficiency concept. This principle encourages the design of highly active nanomaterials by maximizing the number of integrated functional units while minimizing the number of inactive components. State-of-the-art research on reticular nanoparticles-metal-organic frameworks, zeolitic imidazolate frameworks, and covalent organic frameworks-is critically assessed and the beneficial features and particular challenges that set reticular chemistry apart from other nanoparticle material classes are highlighted. Reviewing the power of reticular chemistry, it is suggested that the unique possibility to efficiently and straightforwardly synthesize multifunctional nanoparticles should guide the synthesis of customized nanoparticles in the future
Reduced-reference metric design for objective perceptual quality assessment in wireless imaging
The rapid growth of third and development of future generation mobile systems has led
to an increase in the demand for image and video services. However, the hostile nature
of the wireless channel makes the deployment of such services much more challenging,
as in the case of a wireline system. In this context, the importance of taking care of user
satisfaction with service provisioning as a whole has been recognized. The related useroriented
quality concepts cover end-to-end quality of service and subjective factors such
as experiences with the service. To monitor quality and adapt system resources,
performance indicators that represent service integrity have to be selected and related
to objective measures that correlate well with the quality as perceived by humans. Such
objective perceptual quality metrics can then be utilized to optimize quality perception
associated with applications in technical systems.
In this paper, we focus on the design of reduced-reference objective perceptual
image quality metrics for use in wireless imaging. Specifically, the normalized hybrid
image quality metric (NHlQM) and a perceptual relevance weighted Lp-norm are
designed. The main idea behind both feature-based metrics relates to the fact that the
human visual system (HVS)is trained to extract structural information from the viewing
area. Accordingly, NHlQMand Lp-norm are designed to account for different structural
artifacts that have been observed in our distortion model of a wireless link. The extent
by which individual artifacts are present in a given image is obtained by measuring
related image features. The overall quality measure is then computed as a weighting
sum of the features with the respective perceptual relevance weight obtained from
subjective experiments. The proposed metrics differ mainly in the pooling of the
features and amount of reduced-reference produced. While NHlQM performs the
pooling at the transmitter of the system to produce a single value as reduced-reference,
the Lp-norm requires all involved feature values from the transmitted and received
image to perform the pooling on the feature differences at the receiver. In addition, nonlinear
mapping functions are developed that relate the metric values to predicted mean
opinion scores (MOS) and account for saturations in the HVS. The evaluation of
prediction performance of NHIQM and the Lp-norm reveals their excellent correlation
with human perception in terms of accuracy, monotonicity, and consistency
Psychophysical assessment of perceived interest in natural images: The ROI-D database
We introduce a novel region-of-interest (ROI) database for natural image content, the ROI-D database. The database consists of ROI maps created from manual selections obtained in a psychophysical experiment with 20 participants. The presented stimuli were 42 photographic images taken from 3 publicly available image quality databases. In addition to the ROI selections, dominance ratings were recorded that provide further insight into the interest of the selected ROI in relation to the background. In this paper, the experiment is described, the resulting ROI database is analysed, and possible applications of the database are discussed. The ROI-D database is made freely available to the image processing research community
A Comparative Study of Fixation Density Maps
International audienceFixation density maps (FDM) created from eye tracking experiments are widely used in image processing applications. The FDM are assumed to be reliable ground truths of human visual attention and as such one expects high similarity between FDM created in different laboratories. So far, no studies have analysed the degree of similarity between FDM from independent laboratories and the related impact on the applications. In this paper, we perform a thorough comparison of FDM from three independently conducted eye tracking experiments. We focus on the effect of presentation time and image content and evaluate the impact of the FDM differences on three applications: visual saliency modelling, image quality assessment, and image retargeting. It is shown that the FDM are very similar and that their impact on the applications is low. The individual experiment comparisons, however, are found to be significantly different, showing that inter-laboratory differences strongly depend on the experimental conditions of the laboratories. The FDM are publicly available to the research community
A common framework for the evaluation of psychophysiological visual quality assessment
The assessment of perceived quality based on psychophysiological methods recently gained attraction as it potentiallyovercomes certain flaws of psychophysical approaches. Although studies report promising results, it is not possible toarrive at decisive and comparable conclusions that recommend the use of one or another method for a specific applicationor research question. The video quality expert group started a project on psychophysiological quality assessment to studythese novel approaches and to develop a test plan that enables more systematic research. This test plan comprises of a specificallydesigned set of quality annotated video sequences, suggestions for psychophysiological methods to be studied inquality assessment, and recommendations for the documentation and publications of test results. The test plan is presentedin this article.Celtc-Next 5G Perfecta (2018-00735
Immersive analytics with abstract 3D visualizations: A survey
After a long period of scepticism, more and more publications describe basic research but also practical approaches to how abstract data can be presented in immersive environments for effective and efficient data understanding. Central aspects of this important research question in immersive analytics research are concerned with the use of 3D for visualization, the embedding in the immersive space, the combination with spatial data, suitable interaction paradigms and the evaluation of use cases. We provide a characterization that facilitates the comparison and categorization of published works and present a survey of publications that gives an overview of the state of the art, current trends, and gaps and challenges in current research
Compensation mechanism in tumor cell migration: mesenchymal–amoeboid transition after blocking of pericellular proteolysis
Invasive tumor dissemination in vitro and in vivo involves the proteolytic degradation of ECM barriers. This process, however, is only incompletely attenuated by protease inhibitor–based treatment, suggesting the existence of migratory compensation strategies. In three-dimensional collagen matrices, spindle-shaped proteolytically potent HT-1080 fibrosarcoma and MDA-MB-231 carcinoma cells exhibited a constitutive mesenchymal-type movement including the coclustering of β1 integrins and MT1–matrix metalloproteinase (MMP) at fiber bindings sites and the generation of tube-like proteolytic degradation tracks. Near-total inhibition of MMPs, serine proteases, cathepsins, and other proteases, however, induced a conversion toward spherical morphology at near undiminished migration rates. Sustained protease-independent migration resulted from a flexible amoeba-like shape change, i.e., propulsive squeezing through preexisting matrix gaps and formation of constriction rings in the absence of matrix degradation, concomitant loss of clustered β1 integrins and MT1-MMP from fiber binding sites, and a diffuse cortical distribution of the actin cytoskeleton. Acquisition of protease-independent amoeboid dissemination was confirmed for HT-1080 cells injected into the mouse dermis monitored by intravital multiphoton microscopy. In conclusion, the transition from proteolytic mesenchymal toward nonproteolytic amoeboid movement highlights a supramolecular plasticity mechanism in cell migration and further represents a putative escape mechanism in tumor cell dissemination after abrogation of pericellular proteolysis
Raumwirksamkeit der Digitalisierung
Digitalisierung bedarf konkreter räumlicher Steuerung, und hierbei spielt die Regionalplanung und -entwicklung eine zentrale Rolle. Die Arbeitsgruppe "Raumwirksamkeit der Digitalisierung" der LAG Baden-Württemberg hat zentrale Empfehlungen erarbeitet, die die Bereiche "Steuerung des Ausbaus der digitalen Netze", "Daseinsvorsorge und Gleichwertigkeit der Lebensverhältnisse" und "Datenverfügbarkeit und Planungsprozesse" adressieren und unterlegt diese mit Impulsen für die Regionalentwicklung selbst, für politische Rahmenbedingungen und für die Planungswissenschaften.Digitalization is a matter of specific spatial governance. Regional planning and development play a key role here. The working group entitled "Digitalization and its spatial implications" of the LAG Baden-Württemberg has developed key recommendations that address the areas of "Controlling the Expansion of Digital Networks," "Provision of Public Services and Equivalence of Living Conditions", and "Data Availability and Planning Processes". The working group underpins these with impulses for regional development, for political framework conditions and for planning science
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