scholarly journals Routing Schemes in FANETs: A Survey

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 38 ◽  
Author(s):  
Muhammad Fahad Khan ◽  
Kok-Lim Alvin Yau ◽  
Rafidah Md Noor ◽  
Muhammad Ali Imran
Keyword(s):  
Ad Hoc ◽  
Dimensional Space ◽  
Research Work ◽  
Three Dimensional ◽  
High Energy ◽  
Base Station ◽  
Routing Schemes ◽  
Radio Access ◽  
Comprehensive Survey ◽  
And Performance

Flying ad hoc network (FANET) is a self-organizing wireless network that enables inexpensive, flexible, and easy-to-deploy flying nodes, such as unmanned aerial vehicles (UAVs), to communicate among themselves in the absence of fixed network infrastructure. FANET is one of the emerging networks that has an extensive range of next-generation applications. Hence, FANET plays a significant role in achieving application-based goals. Routing enables the flying nodes to collaborate and coordinate among themselves and to establish routes to radio access infrastructure, particularly FANET base station (BS). With a longer route lifetime, the effects of link disconnections and network partitions reduce. Routing must cater to two main characteristics of FANETs that reduce the route lifetime. Firstly, the collaboration nature requires the flying nodes to exchange messages and to coordinate among themselves, causing high energy consumption. Secondly, the mobility pattern of the flying nodes is highly dynamic in a three-dimensional space and they may be spaced far apart, causing link disconnection. In this paper, we present a comprehensive survey of the limited research work of routing schemes in FANETs. Different aspects, including objectives, challenges, routing metrics, characteristics, and performance measures, are covered. Furthermore, we present open issues.

scholarly journals Array databases: concepts, standards, implementations

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Peter Baumann ◽  
Dimitar Misev ◽  
Vlad Merticariu ◽  
Bang Pham Huu
Keyword(s):  
Service Quality ◽  
Ad Hoc ◽  
Query Language ◽  
Distributed Processing ◽  
Database Systems ◽  
Database Technology ◽  
Comprehensive Survey ◽  
Spatio Temporal ◽  
And Performance ◽  
Array Databases

AbstractMulti-dimensional arrays (also known as raster data or gridded data) play a key role in many, if not all science and engineering domains where they typically represent spatio-temporal sensor, image, simulation output, or statistics “datacubes”. As classic database technology does not support arrays adequately, such data today are maintained mostly in silo solutions, with architectures that tend to erode and not keep up with the increasing requirements on performance and service quality. Array Database systems attempt to close this gap by providing declarative query support for flexible ad-hoc analytics on large n-D arrays, similar to what SQL offers on set-oriented data, XQuery on hierarchical data, and SPARQL and CIPHER on graph data. Today, Petascale Array Database installations exist, employing massive parallelism and distributed processing. Hence, questions arise about technology and standards available, usability, and overall maturity. Several papers have compared models and formalisms, and benchmarks have been undertaken as well, typically comparing two systems against each other. While each of these represent valuable research to the best of our knowledge there is no comprehensive survey combining model, query language, architecture, and practical usability, and performance aspects. The size of this comparison differentiates our study as well with 19 systems compared, four benchmarked to an extent and depth clearly exceeding previous papers in the field; for example, subsetting tests were designed in a way that systems cannot be tuned to specifically these queries. It is hoped that this gives a representative overview to all who want to immerse into the field as well as a clear guidance to those who need to choose the best suited datacube tool for their application. This article presents results of the Research Data Alliance (RDA) Array Database Assessment Working Group (ADA:WG), a subgroup of the Big Data Interest Group. It has elicited the state of the art in Array Databases, technically supported by IEEE GRSS and CODATA Germany, to answer the question: how can data scientists and engineers benefit from Array Database technology? As it turns out, Array Databases can offer significant advantages in terms of flexibility, functionality, extensibility, as well as performance and scalability—in total, the database approach of offering “datacubes” analysis-ready heralds a new level of service quality. Investigation shows that there is a lively ecosystem of technology with increasing uptake, and proven array analytics standards are in place. Consequently, such approaches have to be considered a serious option for datacube services in science, engineering and beyond. Tools, though, vary greatly in functionality and performance as it turns out.

scholarly journals The Formation of a Cavity in a 3D Flux Rope

2013 ◽  
Vol 8 (S300) ◽  
pp. 147-150 ◽  
Author(s):  
Donald Schmit ◽  
Sarah Gibson
Keyword(s):  
Ad Hoc ◽  
Numerical Models ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Flux Rope ◽  
Multiple Structures ◽  
Field Lines ◽  
Hydrostatic Balance ◽  
Distinct Field ◽  
Three Dimensional Space

AbstractThere are currently no three dimensional numerical models which describe the magnetic and energetic formation of prominences self-consistently. Consequently, there has not been significant progress made in understanding the connection between the dense prominence plasma and the coronal cavity. We have taken an ad-hoc approach to understanding the energetic implications of the magnetic models of prominence structure. We extract one dimensional magnetic field lines from a 3D MHD model of a flux rope and solve for hydrostatic balance along these field lines incorporating field-aligned thermal conduction, uniform heating, and radiative losses. The 1D hydrostatic solutions for density and temperature are then mapped back into three dimensional space, which allows us to consider the projection of multiple structures. We find that the 3D flux rope is composed of several distinct field line types. A majority of the flux rope interior field lines are twisted but not dipped. These field lines are density-reduced relative to unsheared arcade field lines. We suggest the cavity may form along these short interior field lines which are surrounded by a sheath of dipped field lines. This geometric arrangement would create a cavity on top of a prominence, but the two structures would not share field lines or plasma.

scholarly journals Pollution Monitoring Based on Vehicle-borne Particulate Quantum Lidar

2020 ◽  
Vol 237 ◽  
pp. 03023
Author(s):  
Xu Wang ◽  
Jing Gao ◽  
Yuefeng Zhao
Keyword(s):  
Environmental Protection ◽  
Dimensional Space ◽  
Three Dimensional ◽  
High Energy ◽  
Pollution Monitoring ◽  
Observation Area ◽  
Surrounding Areas ◽  
Environmental Network ◽  
And Diffusion ◽  
Three Dimensional Space

From February 7 to 10, 2018, due to unfavorable meteorological conditions, a process of air pollution occurred in Hefei and its surrounding areas, and moderate to severe pollution occurred in the municipal districts. Aiming at the pollution process in Hefei City, under the leadership of Hefei Environmental Protection Bureau and with the support of Hefei Environmental Protection Sub-bureau, four fixed observation points were selected to carry out all-weather environmental network monitoring pilot projects in Hefei municipal jurisdiction area. At the same time, a "mobile monitoring vehicle of atmospheric environmental pollution" was arranged to conduct all-weather walking observation to real-time monitor the spatial distribution and three-dimensional space of pollutants in Hefei urban area、inter-transport and space subsidence and diffusion. The RaySound Series Portable high-energy high-frequency lidar was used in the environmental networking monitoring in Hefei. The air quality in the observation area was evaluated comprehensively by using the mode of fixed vertical monitoring, plane scanning monitoring and mobile walking monitoring.

Modeling and Management of Location and Mobility

2011 ◽  
pp. 177-212 ◽  
Author(s):  
Wenye Wang
Keyword(s):  
Ad Hoc ◽  
System Capacity ◽  
Mobility Modeling ◽  
Mobile Objects ◽  
Comprehensive Survey ◽  
Location Modeling ◽  
Increasing Demand ◽  
Formulation Analysis ◽  
And Performance ◽  
Hoc Networks

Location modeling represents inclusive mobile objects and their relationship in space, dealing with how to describe a mobile object’s location. The goal of mobility modeling, on the other hand, is to predict or statistically estimate the movement of mobile objects. With the increasing demand for multimedia applications, location-aware services, and system capacity, many recognize that modeling and management of location and mobility is becoming critical to locating mobile objects in wireless information networks. Mobility modeling and location management strongly influence the design and performance of wireless networks in many aspects, such as routing, network planning, handoff, call admission control, and so forth. In this chapter, we present a comprehensive survey of mobility and location models, and schemes used for location-mobility management in cellular and ad hoc networks, which are discussed along with necessary, but understandable, formulation, analysis, and discussions.

scholarly journals Research on 3D Fingerprint Positioning Based on MIMO Base Station

2021 ◽  
Author(s):  
Chang Xia ◽  
Yijie Ren ◽  
Xiaojun Wang ◽  
Weiguang Sun ◽  
Fei Tang ◽  
...  
Keyword(s):  
Reference Point ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Base Station ◽  
Localization Algorithm ◽  
Positioning Accuracy ◽  
Positioning Method ◽  
High Base ◽  
Effective Use ◽  
Three Dimensional Space

The aim of this article is to solve the problem that the accuracy of traditional positioning algorithm decreases in complex environment and to provide some ideas for the few researches of fingerprint localization algorithm in three-dimensional space. This paper builds a system model in a three-dimensional space, provides three reference point distribution methods, and discusses the positioning performance under these distribution methods. After that, based on the high base station deployment density, multi-point fusion positioning method is used to locate the target, which further improves the positioning accuracy and makes more effective use of reference point resources. Finally, a backward-assisted positioning method is proposed, which uses the position information of the positioned points to assist the positioning of the current point. Research shows that this method can improve the positioning accuracy and has good versatility. (Foundation items: Social Development Projects of Jiangsu Science and Technology Department (No.BE2018704).)

scholarly journals A Pseudo-Immersive Virtual Environment - a Shell for Research

1996 ◽  
Vol 2 (3) ◽  
pp. 1-14
Author(s):  
Jing-Jing Fang ◽  
Douglas E.R. Clark ◽  
John E. L. Simmons
Keyword(s):  
Virtual Reality ◽  
Virtual Environment ◽  
Dimensional Space ◽  
Research Work ◽  
Three Dimensional ◽  
Virtual Space ◽  
Mechanical Assembly ◽  
Software Interface ◽  
Immersive Virtual Environment ◽  
Three Dimensional Space

The authors built a pseudo-immersive three-dimensional computer generated virtual environment (VE) as a shell for research in detailed collision detection. The purpose of the virtual world construction described in this paper is to handle engineering applications such as the mechanical assembly and disassembly of complex systems. A virtual space ball is attached to the VE in order to control the motion of virtual objects in that environment. This software interface simulates a real three-dimensional space ball device. The contribution of the pseudo-immersive system removes the absolute necessity for expensive Virtual Reality equipment and software for research work on virtual reality.

Investigation on the traveling wave and three-dimensional trajectory of motion on the stator of rotational ultrasonic motors

2020 ◽  
Vol 64 (1-4) ◽  
pp. 631-638
Author(s):  
Hucheng Chen ◽  
Wei Han ◽  
Jinhao Qiu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Traveling Wave ◽  
Dimensional Space ◽  
Computational Cost ◽  
Three Dimensional ◽  
Element Model ◽  
Input Voltage ◽  
Ultrasonic Motors ◽  
And Performance

Better understanding of the characteristics of the traveling wave and three-dimensional trajectory related to motion on the surface of the stator is very important for the design and performance improvement of the ultrasonic motors. In this paper, an accurate finite element model of a single stator with a fully coupled piezoelectric layer was established at a moderate computational cost. The finite element model was verified by experimental test at the inverse resonance point. Based on this model, the traveling wave and three-dimensional trajectory of stator surface, including the influence of the input voltage on the phase and amplitude of the displacements in three directions, are investigated. The results show that the trajectory of particles on the stator surface is an ellipse in three-dimensional space due to the phase differences between the three components of displacement in the radial, circumferential and axial directions. The amplitude of radial displacement is about 39.5% of that in the circumferential displacement, which should not be neglected.

scholarly journals A Comprehensive Survey on Opportunistic Routing Protocols for MANETs: Issues, Challenges and Future Directions

2019 ◽  
Author(s):  
Varun G Menon
Keyword(s):  
Ad Hoc Networks ◽  
Routing Protocols ◽  
Resource Sharing ◽  
Ad Hoc ◽  
Research Work ◽  
Opportunistic Routing ◽  
Future Research ◽  
Wireless Medium ◽  
Comprehensive Survey ◽  
Hoc Networks

Opportunistic routing is the latest technique that uses the broadcasting nature of the wireless medium to increase the number of potential forwarding nodes in the network. This, in turn improves the delivery rate and reliability of data transmission in the network. Compared to all previous classes of routing protocols, opportunistic routing offers numerous advantages which is exploited by the latest applications for efficient communication and resource sharing in dynamic ad hoc networks. These applications provide dynamic communication in disaster recovery environments. The objective of this research work is to review and classify all the major opportunistic routing protocols proposed for dynamic ad hoc networks. Further the issues and challenges with each of these existing protocol is discussed and future research directions are put forward

scholarly journals Design and Performance Analysis of Multi-tier Heterogeneous Network through Coverage, Throughput and Energy Efficiency

2017 ◽  
Vol 7 (6) ◽  
pp. 2345-2350
Author(s):  
A. Shabbir ◽  
H. R. Khan ◽  
S. A. Ali ◽  
S. Rizvi
Keyword(s):  
Energy Efficiency ◽  
Heterogeneous Network ◽  
Capital Expenditure ◽  
Research Work ◽  
Future Generation ◽  
High Energy ◽  
Base Stations ◽  
Throughput Capacity ◽  
And Performance ◽  
Capacity And Coverage

The unprecedented acceleration in wireless industry strongly compels wireless operators to increase their data network throughput, capacity and coverage on emergent basis. In upcoming 5G heterogeneous networks inclusion of low power nodes (LPNs) like pico cells and femto cells for increasing network’s throughput, capacity and coverage are getting momentum. Addition of LPNs in such a massive level will eventually make a network populated in terms of base stations (BSs).The dense deployments of BSs will leads towards high operating expenditures (Op-Ex), capital expenditure (Cap-Ex) and most importantly high energy consumption in future generation networks. Recognizing theses networks issues this research work investigates data throughput and energy efficiency of 5G multi-tier heterogeneous network. The network is modeled using tools from stochastic geometry. Monte Carlo results confirmed that rational deployment of LPNs can contribute towards increased throughput along with better energy efficiency of overall network.

scholarly journals NiFe LDH@Super P Nanocomposite as an Efficient Electrocatalyst for Oxygen Evolution Reaction

2021 ◽  
Vol 257 ◽  
pp. 01029
Author(s):  
Li Ren ◽  
Jiaqi Wang ◽  
Bing Xue ◽  
Fangfei Li
Keyword(s):  
Precious Metal ◽  
Dimensional Space ◽  
Research Work ◽  
Three Dimensional ◽  
Treatment Method ◽  
Alkaline Media ◽  
Simple Method ◽  
Composite Effect ◽  
Highly Active ◽  
Full Contact

NiFe LDH (Layered Double Hydroxide) is a promising electrocatalyst for oxygen release reaction (OER), which is currently receiving more and more attention. Here, we propose a simple method to enhance the OER activity of NiFe LDH supported on Super P. The NiFe LDH@Super P catalyst with a nanoflower nanostructure was successfully synthesized via pre-hydrothermal treatment method, which ensures the normal nucleation process of the highly active NiFe LDH precursor and significantly promote the full contact of NiFe LDH and Super P in the three-dimensional space. The as synthesized NiFe LDH@Super P-2h sample exhibited excellent OER performances in alkaline media, and the overpotential is only 260 mV at a current density of 10 mA · cm-2. The outstanding OER electrocatalytic reaction performance is attributed to the unique three-dimensional nanoflower structure and excellent composite effect with Super P, which provides more specific surface areas and enables efficient transfer of electrons between them. This research work provides a simple and effective method for developing non-precious metal-based OER catalysts to replace expensive precious metal catalysts.

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