Search results for "Formas"
showing 10 items of 979 documents
Dažas piezīmes par Servija Tullija centūriju satversmi
1939
"Atsevišķs novilkums no Latv. Univ. Akadem. Sabiedrisko Zinātņu B-dr. Rakstu krājuma II".
Bright spots as climate‐smart marine spatial planning tools for conservation and blue growth
2021
Marine spatial planning that addresses ocean climate-driven change (‘climate-smart MSP’) is a global aspiration to support economic growth, food security and ecosystem sustainability. Ocean climate change (‘CC’) modelling may become a key decision-support tool for MSP, but traditional modelling analysis and communication challenges prevent their broad uptake. We employed MSP-specific ocean climate modelling analyses to inform a real-life MSP process; addressing how nature conservation and fisheries could be adapted to CC. We found that the currently planned distribution of these activities may become unsustainable during the policy's implementation due to CC, leading to a shortfall in its s…
Location-Free Spectrum Cartography
2019
Spectrum cartography constructs maps of metrics such as channel gain or received signal power across a geographic area of interest using spatially distributed sensor measurements. Applications of these maps include network planning, interference coordination, power control, localization, and cognitive radios to name a few. Since existing spectrum cartography techniques require accurate estimates of the sensor locations, their performance is drastically impaired by multipath affecting the positioning pilot signals, as occurs in indoor or dense urban scenarios. To overcome such a limitation, this paper introduces a novel paradigm for spectrum cartography, where estimation of spectral maps rel…
Channel Gain Cartography via Mixture of Experts
2020
In order to estimate the channel gain (CG) between the locations of an arbitrary transceiver pair across a geographic area of interest, CG maps can be constructed from spatially distributed sensor measurements. Most approaches to build such spectrum maps are location-based, meaning that the input variable to the estimating function is a pair of spatial locations. The performance of such maps depends critically on the ability of the sensors to determine their positions, which may be drastically impaired if the positioning pilot signals are affected by multi-path channels. An alternative location-free approach was recently proposed for spectrum power maps, where the input variable to the maps…
Data-Driven Spectrum Cartography via Deep Completion Autoencoders
2019
Spectrum maps, which provide RF spectrum metrics such as power spectral density for every location in a geographic area, find numerous applications in wireless communications such as interference control, spectrum management, resource allocation, and network planning to name a few. Spectrum cartography techniques construct these maps from a collection of measurements collected by spatially distributed sensors. Due to the nature of the propagation of electromagnetic waves, spectrum maps are complicated functions of the spatial coordinates. For this reason, model-free approaches have been preferred. However, all existing schemes rely on some interpolation algorithm unable to learn from data. …
Learning Automata Based Q-learning for Content Placement in Cooperative Caching
2019
An optimization problem of content placement in cooperative caching is formulated, with the aim of maximizing sum mean opinion score (MOS) of mobile users. Firstly, a supervised feed-forward back-propagation connectionist model based neural network (SFBC-NN) is invoked for user mobility and content popularity prediction. More particularly, practical data collected from GPS-tracker app on smartphones is tackled to test the accuracy of mobility prediction. Then, a learning automata-based Q-learning (LAQL) algorithm for cooperative caching is proposed, in which learning automata (LA) is invoked for Q-learning to obtain an optimal action selection in a random and stationary environment. It is p…
Social Media Data in an Augmented Reality System for Situation Awareness Support in Emergency Control Rooms
2021
AbstractDuring crisis situations, emergency operators require fast information access to achieve situation awareness and make the best possible decisions. Augmented reality could be used to visualize the wealth of user-generated content available on social media and enable context-adaptive functions for emergency operators. Although emergency operators agree that social media analytics will be important for their future work, it poses a challenge to filter and visualize large amounts of social media data. We conducted a goal-directed task analysis to identify the situation awareness requirements of emergency operators. By collecting tweets during two storms in Germany we evaluated the usefu…
Supporting Inter-Agency Collaboration in Emergency Management: Recurring Challenges Relevant for CSCW
2023
Emergency management requires effective collaboration between different agencies. This work implies several challenges due to a heterogeneous mix of actors with different procedures, practices, and support tools. Despite being focused in various research streams, emergency responders still report challenges with sharing information and establishing shared situational awareness in responding to complex events. The paper presents results from a large-scale digital tabletop exercise that illustrate recurring challenges related to support for collaborative procedures, a communication network structure combining several media, use of geocollaborative tools, and configuration of collaborative env…
Understanding Situational Disabilities and Situational Awareness in Disasters
2019
In this paper, a scenario-based approach augmented with personas typically used in universal design and interactive design domains is used to illustrate the occurrence of situational disabilities in emergency situations, and to show how environmental factors can trigger these situational disabilities. With the help of personas representing selected archetypical characteristics and roles, the scenarios are further examined to show how these situational disabilities can affect the situational awareness of different stakeholders, not only in the command and control centers, but also first responders in the field as well as affected members of the public. This approach provides a better underst…
Entrevista para el diario ABC
1994
Entrevista a José Vidal-Beneyto realizada por Isabel San Sebastián para el diario "ABC". Se desconoce si finalmente fue publicada.