A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

Efficient numerical computation and experimental study of temporally long equilibrium scour development around abutment

YesFor the abutment bed scour to reach its equilibrium state, a long flow time is needed. Hence, the employment of usual strategy of simulating such scouring event using the 3D numerical model is very time consuming and less practical. In order to develop an applicable model to consider temporally long abutment scouring process, this study modifies the common approach of 2D shallow water equations (SWEs) model to account for the sediment transport and turbulence, and provides a realistic approach to simulate the long scouring process to reach the full scour equilibrium. Due to the high demand of the 2D SWEs numerical scheme performance to simulate the abutment bed scouring, a recently proposed surface gradient upwind method (SGUM) was also used to improve the simulation of the numerical source terms. The abutment scour experiments of this study were conducted using the facility of Hydraulics Laboratory at Nanyang Technological University, Singapore to compare with the presented 2D SGUM-SWEs model. Fifteen experiments were conducted over a total period of 3059.7 hours experimental time (over 4.2 months). The comparison shows that the 2D SGUM-SWEs model gives good representation to the experimental results with the practical advantage

Socially and biologically inspired computing for self-organizing communications networks

The design and development of future communications networks call for a careful examination of biological and social systems. New technological developments like self-driving cars, wireless sensor networks, drones swarm, Internet of Things, Big Data, and Blockchain are promoting an integration process that will bring together all those technologies in a large-scale heterogeneous network. Most of the challenges related to these new developments cannot be faced using traditional approaches, and require to explore novel paradigms for building computational mechanisms that allow us to deal with the emergent complexity of these new applications. In this article, we show that it is possible to use biologically and socially inspired computing for designing and implementing self-organizing communication systems. We argue that an abstract analysis of biological and social phenomena can be made to develop computational models that provide a suitable conceptual framework for building new networking technologies: biologically inspired computing for achieving efficient and scalable networking under uncertain environments; socially inspired computing for increasing the capacity of a system for solving problems through collective actions. We aim to enhance the state-of-the-art of these approaches and encourage other researchers to use these models in their future work

Glucosinolates within a collection of white head cabbages (Brassica oleracea var. capitata sub.var. alba) from Turkey

Glucosinolates of a population of white head cabbages collected from different geographical regions of Turkey were determined at two different plant developmental stages (early and late development). Theglucosinolates detected were glucoiberin, glucoraphanin, sinigrin of aliphatics and glucobrassicin, neoglucobrassicin, 4-methoxyglucobrassicin and 4-hydroxyglucobrassicin of indoles. Variation were observed in terms of glucosinolate profile and levels. However, the most abundant glucosinolate observed was glucobrassicin synthesized at significantly high levels. While total aliphatic glucosinolate content of genotypes ranged from 0.33 - 5.63 ìmolg-1 dw and 0.46 - 16.14 ìmolg-1 dw at early and latedevelopmental stages, respectively, in the first year, the levels ranged from 0.05 - 7.72 ìmolg-1 dw and 0.12 - 14.60 ìmolg-1 dw at early and late developmental stages, respectively, in the second experimentalyear. In general, aliphatic glucosinolate content of cabbages were low compared to indoles; glucobrassicin in particular. The presence of glucoiberin and glucoraphanin in almost all cabbage genotypes is promising. Potential individuals synthesizing aliphatic glucosinolates together with glucobrassicin at relatively higher levels were selected for future breeding purposes aimed to develop novel lines with improved health benefits. Results suggested that both aliphatic and indoleglucosinolate levels were higher at later stages of development

Trajectory-aware Ad hoc Routing Protocol for Micro Aerial Vehicle Networks

Micro Aerial Vehicles (MAVs) are small unmanned aerial vehicles (UAVs) that are generally equipped with camera, GPS and other sensors and are envisioned for many civil and commercial applications. Some of these applications require transmitting multimedia traffic and demand for a high wireless network throughput. In this paper, we consider an application scenario where a team of MAVs cover multiple areas of interest; e.g., during sports events, following known trajectories (mobility paths) and transmitting continuous streams of sensed traffic (images or video) to a ground station. We propose a Route Switching (RS) algorithm that utilizes both the location and the trajectory information of the MAVs to schedule and update routes to seamlessly transmit traffic to the destination. Simulation results show improved network performance in terms of throughput in comparison to Ad-hoc On demand Distance Vector (AODV) and Location Aided Routing (LAR) since the proposed algorithm exploits the added path information for route discovery

Anomalous ferromagnetic behaviour of Y₂O₃ and CuO nanoparticles in YBa₂Cu₃Oy superconductor

Anomalous ferromagnetic behaviour of the Y₂O₃ and CuO components in YBa₂Cu₃O[subscript y] (Y123) was observed after severe reduction of particle size. The particle size reduction was performed in two ways. First, Y₂O₃, BaCO₃ and CuO were ground for different times to reduce the particle size to the nanoscale. It was found that the superconducting phase could not be obtained without heat treatment, but a weak ferromagnetic behaviour of the mixture was observed at liquid and room temperatures. Second, preheated Y123 powders were subjected to grinding for various times followed by a second sintering process. It was found that the superconducting transition temperature, T[subscript c], was strongly suppressed by increasing grinding time, and ferromagnetic behaviour at both room and liquid nitrogen temperatures was also observed. In order to understand which compound is responsible for this weak ferromagnetism, the Y₂O₃, BaCO₃ and CuO powders were separately ground and M-H loops taken at 290 K. The results indicated that both Y₂O₃ and CuO powders showed weak ferromagnetism, but BaCO₃ showed anti ferromagnetism. It is thought that energy transfer to the powder particles by grinding results in severe plastic deformation of the particles to produce dislocations, vacancies and atomic disorder. We discuss then the observations in the context of recent studies of the magnetic properties of nanoscale oxide materials

Vegetable seed production in turkey

International Symposium on Agrotechnics and Storage of Vegetable and Ornamental Seeds/5th International Symposium on Seed Research in Horticulture -- JUN 14-16, 1993 -- BARI, ITALYWOS: A1994BD97V00001…Int Soc Hort Sci, Working Grp Seed Re

Genetic characterization of pea (Pisum sativum) germplasm from Turkey using morphological and SSR markers

The need for the conservation of plant genetic resources has been widely accepted. Germplasm characterization and evaluation yield information for more efficient utilization of these valuable resources. The aim of the present study was to characterize the pea germplasm conserved at the Aegean Agricultural Research Institute of Turkey using morphological and simple sequence repeat (SSR)-based molecular approaches. Genetic characterization of 30 pea genotypes collected from different regions of Turkey and 10 commercial pea cultivars was performed using the criteria of the International Union for the Protection of New Varieties of Plants (UPOV) (TG 7/9 Pisum sativum), and with 10 SSR markers. We originally tested 15 SSR markers; 10 of these markers were selected on the basis of high polymorphism information content in the molecular assays. Sixty-one alleles were detected at the 10 loci. The number of alleles per SSR locus ranged from 3 (PVSBE2) to 12 (AB53), with a mean of 6.1 alleles. The most informative loci were AB53 (12 alleles), AA355 (9 alleles), AD270 (8 alleles), A9 (7 alleles), AD61 (7 alleles), and AB25 (6 alleles). The UPGMA dendrogram defined by SSR markers revealed genetic relatedness of the pea genotypes. These findings can be used to guide future breeding studies and germplasm management of these pea genotypes