Search results for " networking"

A comprehensive in situ and remote sensing data set from the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign

2019

The Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD) campaign was carried out north-west of Svalbard (Norway) between 23 May and 6 June 2017. The objective of ACLOUD was to study Arctic boundary layer and mid-level clouds and their role in Arctic amplification. Two research aircraft (Polar 5 and 6) jointly performed 22 research flights over the transition zone between open ocean and closed sea ice. Both aircraft were equipped with identical instrumentation for measurements of basic meteorological parameters, as well as for turbulent and radiative energy fluxes. In addition, on Polar 5 active and passive remote sensing instruments were installed, while Polar 6 …

Edge-Based Missing Data Imputation in Large-Scale Environments

2021

Smart cities leverage large amounts of data acquired in the urban environment in the context of decision support tools. These tools enable monitoring the environment to improve the quality of services offered to citizens. The increasing diffusion of personal Internet of things devices capable of sensing the physical environment allows for low-cost solutions to acquire a large amount of information within the urban environment. On the one hand, the use of mobile and intermittent sensors implies new scenarios of large-scale data analysis

Exploring Effective Ecosystems in Disaster Management: Case studies of Japan and Nepal

2017

Planktic foraminiferal changes in the western Mediterranean Anthropocene

2021

The increase in anthropogenic induced warming over the last two centuries is impacting marine environment. Planktic foraminifera are a globally distributed calcifying marine zooplankton responding sensitively to changes in sea surface temperatures and interacting with the food web structure. Here, we study two high resolution multicore records from two western Mediterranean Sea regions (Alboran and Balearic basins), areas highly affected by both natural climate change and anthropogenic warming. Cores cover the time interval from the Medieval Climate Anomaly to present. Reconstructed sea surface temperatures are in good agreement with other results, tracing temperature changes through the Co…

A Geometry-Based Underwater Acoustic Channel Model Allowing for Sloped Ocean Bottom Conditions

2017

This paper proposes a new geometry-based channel model for shallow-water ocean environments, in which the ocean bottom can slope gently down/up. The need for developing such an underwater acoustic (UWA) channel model is driven by the fact that the standard assumption of a flat ocean bottom does not hold in many realistic scenarios. Starting from a geometrical model, we develop a stochastic channel model for wideband single-input single-output vehicle-to-vehicle UWA channels using the ray theory assuming smooth ocean surface and bottom. We investigate the effect of the ocean-bottom slope angle on the distribution of the channel envelope, instantaneous channel capacity, temporal autocorrelati…

A Nonisovelocity Geometry-Based Underwater Acoustic Channel Model

2018

This paper proposes a new geometry-based shallow underwater acoustic (UWA) channel model allowing for nonisovelocity ocean conditions. The fact that the isovelocity assumption does not hold in many real-world scenarios motivates the need for developing channel models for nonisovelocity UWA propagation environments. Starting from a geometrical model, we develop a stochastic channel model for a single-input single-output (SISO) vehicle-to-vehicle UWA channel assuming that the ocean surface and bottom are rough and that the speed of sound varies with depth. The effect of the nonisovelocity condition has been assessed regarding its influence on the temporal autocorrelation function, the frequen…

Seaport competitiveness research: the past, present and future

2019

This study presents a review of articles with a focus on seaport competitiveness from the maritime literature. We investigated how port competitiveness research has evolved during the last two decades using bibliometric citation analysis tools and techniques. Bibliography data, collected from the ISI Web of Science database, consisted of 267 research papers by 465 authors in 117 journals. Based on citation analysis, we identified the key universities, journals and articles and their impact on port competitiveness research. Also, seven key research streams with few sub-streams were revealed as a result of a mixed co-citation and in-depth content analysis of the most cited articles. A bibliom…

Konforme Abbildung und Greensche Funktion

1949

Mit Hilfe des Additionstheorems Gl. (I, 31) und mit Hilfe der imaginaren Transformation von Jacobi Gl. (I, 33) folgt fur die durch die Funktion λ = sn (z, k) vermittelte, Abbildung der z-Ebene auf die λ-Ebene $$\lambda = {\lambda _1} + i{\lambda _2} = snz = sn\left( {x + iy} \right) = \frac{{snxcniydniy + sniycnxdnx}}{{1 - {k^2}s{n^2}xs{n^2}iy}}$$ .

Peer-to-peer cooperative GNSS-based localization for stationary reference nodes in wireless sensor networks

2017

Most localization algorithms in wireless sensor networks rely on a few reference nodes with known locations to estimate the locations of unknown nodes. The locations of reference nodes can be either manually configured or, more practically, obtained by means of some satellite-based positioning system(s). However, satellite-based locations may be inaccurate and imprecise, which results in reduced location accuracy of localization algorithms. This paper proposes a peer-to-peer cooperative GNSS-based localization algorithm for stationary reference nodes to improve their relative location accuracy and precision. The algorithm applies simple statistical methods and GNSS-based information from mu…

Massively Parallel ANS Decoding on GPUs

2019

In recent years, graphics processors have enabled significant advances in the fields of big data and streamed deep learning. In order to keep control of rapidly growing amounts of data and to achieve sufficient throughput rates, compression features are a key part of many applications including popular deep learning pipelines. However, as most of the respective APIs rely on CPU-based preprocessing for decoding, data decompression frequently becomes a bottleneck in accelerated compute systems. This establishes the need for efficient GPU-based solutions for decompression. Asymmetric numeral systems (ANS) represent a modern approach to entropy coding, combining superior compression results wit…