Search results for "Context"
showing 10 items of 6304 documents
VentQsys: Low-cost open IoT system for CO2 monitoring in classrooms
2021
AbstractIn educational context, a source of nuisance for students is carbon dioxide ($$CO_2$$ C O 2 ) concentration due to closed rooms and lack of ventilation or circulatory air. Also, in the pandemic context, ventilation in indoor environments has been proven as a good tool to control the COVID-19 infections. In this work, it is presented a low cost IoT-based open-hardware and open-software monitoring system to control ventilation, by measuring carbon dioxide ($$CO_2$$ C O 2 ), temperature and relative humidity. This system provides also support for automatic updating, auto-self calibration and adds some Cloud and Edge offloading of computational features for mapping functionalities. From…
Optimization of urban delivery systems based on electric assisted cargo bikes with modular battery size, taking into account the service requirements…
2021
The implementation of new forms of urban mobility is a fundamental challenge for improving the performance of city logistic systems in terms of efficiency and sustainability. For such purposes, the exploitation of electric vehicles is currently being investigated as an alternative to traditional internal combustion engines. In particular, the employment of lightweight electric cargo bikes is seen as an attractive possibility for designing improved city distribution systems. Such vehicles, however, present substantial limitations related to their endurance, speed, power, and recharging times; therefore, their configuration must be optimized considering the actual operational context and the …
An energy autonomous and battery-free measurement system for ambient light power with time domain readout
2021
Abstract Internet of Things (IoT) provides more and more adequate infrastructures for many applications and advanced services. This context promotes the ability to satisfy the growing demand for innovative measuring systems, increasingly popular with intelligent nodes, totally wireless, easy to install that require the least possible maintenance. This paper aims to contribute to the state-of-the-art with an energy-autonomous and battery-free measurement platform designed to measure the ambient light power when its level exceeds the Limit of Detection (LoD) threshold. The proposed system consists of a single photovoltaic transducer to harvest energy and simultaneously detect ambient light. T…
Medical news aggregation and ranking of taking into account the user needs
2019
The purpose of this work is to develop an intelligent information system that is designed for aggregation and ranking of news taking into account the needs of the user. The online market for mass media and the needs of readers, the purpose of their searches and moments is not enough to find the news is analyzed. A conceptual model of the information aggression system and ranking of news that would enable presentation of the work of the future intellectual information system, to show its structure is constructed. The methods and means for implementation of the intellectual information system are selected. An online resource for aggregation and ranking of news, news feeds and flexible setting…
Low-complexity AoA and AoD Estimation in the Transformed Spatial Domain for Millimeter Wave MIMO Channels
2021
High-accuracy angle of arrival (AoA) and angle of departure (AoD) estimation is critical for cell search, stable communications and positioning in millimeter wave (mmWave) cellular systems. Moreover, the design of low-complexity AoA/AoD estimation algorithms is also of major importance in the deployment of practical systems to enable a fast and resource-efficient computation of beamforming weights. Parametric mmWave channel estimation allows to describe the channel matrix as a combination of direction-dependent signal paths, exploiting the sparse characteristics of mmWave channels. In this context, a fast Transformed Spatial Domain Channel Estimation (TSDCE) algorithm was recently proposed …
Clustering-Assisted 3D Beamforming for Throughput Maximization in mmWave Networks
2021
Beamforming schemes have been widely used to improve network throughput in 5G mmWave networks. However, 3D beamforming schemes have hereto not been investigated in this context. In this work, a cluster-assisted 3D beamforming scheme is proposed to optimize the downtilt angle for network coverage and throughput maximization. User Equipment (UEs) are clustered based on inter-user and the inter-cluster distances. The interference is accounted from the adjacent clusters and thus frequency resources can be assigned to the non-adjacent clusters. Optimal downtilt angles are obtained for every cluster to maximize the throughput while considering the interference from adjacent clusters. 3D beam patt…
Water transmission properties of a sandy-loam soil estimated with Beerkan runs differing by the infiltration time criterion
2021
Abstract The Beerkan method consists of a ponded infiltration experiment from a single ring inserted a small depth into the soil. Fixed, small volumes of water are repeatedly poured into the ring to maintain a quasi-zero head on the soil surface. According to the standard Beerkan infiltration run, a new water volume is poured on the infiltration surface when the previously applied volume has completely infiltrated and the soil surface is entirely exposed to air (ta criterion). However, water could also be applied when the soil exposition to air begins (to criterion) or half the soil surface is exposed to air (tm criterion). The effect of the infiltration time criterion on determination of t…
Movement dependent position changes of the antennular flagellum ofPalaemon xiphias (Risso)
1977
The angular positions of the outer flagellum ofPalaemon xiphias were obtained by cinematographic measurements during different phases of locomotion. Contrary to the upright resting position the flagella are stretched forward into a distinct starting position preliminary to any forward movement, and then pushed down with acceleration of swimming speed. These phenomena are discussed in context with comparable behaviour in other decapods and in insects.
Forewarned is forearmed: aggression and information use determine fitness costs of slave raids
2014
Many animals use reliable indicators of upcoming events such as antagonistic interactions to prepare themselves. In group-living animals, not only the cue perceiving individuals are involved in mobilization, but the entire group can use this information. In this study, we analyze whether social insects, which perceive reliable information on an upcoming social parasite attack, can use this knowledge to better defend their colony. We focus on the interaction between the ant Temnothorax longispinosus and the slave-making ant Protomognathus americanus, which conducts destructive raids on host colonies to steal their brood. As a behavioral defense, host colonies show aggression, which has a con…
Social capital development of rural community based on social networking activities in Lithuania
2018
The scholar literature on simultaneous using of social capital explore knowledge and identity resources as well as actions and interactions benefiting the community through personal bonds of individuals; issues of common trust; and adapting the current understanding in new situations. In this article, we instead examine rural community influence on social capital building of adult person in a virtual community. A quantitative survey was done in 246 local rural communities in Lithuania which reflected their community activities on a virtual basis. From the data of 500 informants we found that rural community (human social network) members were also active in the virtual communities. Research…