scholarly journals Inter-UAV Routing Scheme Testbeds

Drones ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 2
Author(s):  
Georgios Amponis ◽  
Thomas Lagkas ◽  
Panagiotis Sarigiannidis ◽  
Vasileios Vitsas ◽  
Panagiotis Fouliras
Keyword(s):  
Signal To Noise Ratio ◽  
Real Life ◽  
Simulation Software ◽  
Propagation Models ◽  
Routing Schemes ◽  
Routing Scheme ◽  
Related Information ◽  
Efficient Control ◽  
Communication Architectures ◽  
Scheme Evaluation

With the development of more advanced and efficient control algorithms and communication architectures, UAVs and networks thereof (swarms) now find applications in nearly all possible environments and scenarios. There exist numerous schemes which accommodate routing for such networks, many of which are specifically designed for distinct use-cases. Validation and evaluation of routing schemes is implemented for the most part using simulation software. This approach is however incapable of considering real-life noise, radio propagation models, channel bit error rate and signal-to-noise ratio. Most importantly, existing frameworks or simulation software cannot sense physical-layer related information regarding power consumption which an increasing number of routing protocols utilize as a metric. The work presented in this paper contributes to the analysis of already existing routing scheme evaluation frameworks and testbeds and proposes an efficient, universal and standardized hardware testbed. Additionally, three interface modes aimed at evaluation under different scenarios are provided.

scholarly journals Overcoming detection loss and noise in squeezing-based optical sensing

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Gaetano Frascella ◽  
Sascha Agne ◽  
Farid Ya. Khalili ◽  
Maria V. Chekhova
Keyword(s):  
Shot Noise ◽  
Optical Sensing ◽  
Detection Efficiency ◽  
Signal To Noise Ratio ◽  
Real Life ◽  
Squeezed States ◽  
Squeezed Light ◽  
Noise Limit ◽  
Imaging And Spectroscopy ◽  
Shot Noise Limit

AbstractAmong the known resources of quantum metrology, one of the most practical and efficient is squeezing. Squeezed states of atoms and light improve the sensing of the phase, magnetic field, polarization, mechanical displacement. They promise to considerably increase signal-to-noise ratio in imaging and spectroscopy, and are already used in real-life gravitational-wave detectors. But despite being more robust than other states, they are still very fragile, which narrows the scope of their application. In particular, squeezed states are useless in measurements where the detection is inefficient or the noise is high. Here, we experimentally demonstrate a remedy against loss and noise: strong noiseless amplification before detection. This way, we achieve loss-tolerant operation of an interferometer fed with squeezed and coherent light. With only 50% detection efficiency and with noise exceeding the level of squeezed light more than 50 times, we overcome the shot-noise limit by 6 dB. Sub-shot-noise phase sensitivity survives up to 87% loss. Application of this technique to other types of optical sensing and imaging promises a full use of quantum resources in these fields.

scholarly journals CAD integrated automatic recognition of weld paths

2021 ◽  
Author(s):  
Tuan Anh Tran ◽  
Andrei Lobov ◽  
Tord Hansen Kaasa ◽  
Morten Bjelland ◽  
Ole Terje Midling
Keyword(s):  
Life Cycle ◽  
Spatial Analysis ◽  
Product Life Cycle ◽  
Real Life ◽  
Automatic Recognition ◽  
Integrated Method ◽  
Weld Joints ◽  
Related Information ◽  
Almost All ◽  
Sequential Assembly

AbstractIn this paper, a CAD integrated method is proposed for automatic recognition of potential weld locations in large assembly structures predominantly comprised of weld joints. The intention is to reduce the total man-hours spent on manually locating, assigning, and maintaining weld-related information throughout the product life cycle. The method utilizes spatial analysis of extracted stereolithographic data in combination with available CAD functions to determine whether the accessibility surrounding a given intersection edge is sufficient for welding. To demonstrate the method, a system is developed in Siemens NX using their NXOpen Python API. The paper presents the application of the method to real-life use cases in varying complexity in cooperation with industrial partners. The system is able to correctly recognize almost all weld lines for the parts considered within a few minutes. Some exceptions are known for particular intersection lines located deep within notched joints and geometries weldable through sequential assembly, which are left as a subject to further works.

scholarly journals Energy-efficient routing in the proximity of a complicated hole in wireless sensor networks

2021 ◽  
Author(s):  
Khanh-Van Nguyen ◽  
Chi-Hieu Nguyen ◽  
Phi Le Nguyen ◽  
Tien Van Do ◽  
Imrich Chlamtac
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Geographic Routing ◽  
Routing Algorithms ◽  
Sensor Nodes ◽  
Wireless Sensor ◽  
Energy Efficient Routing ◽  
Routing Schemes ◽  
Routing Scheme ◽  
Effective Manner

AbstractA quest for geographic routing schemes of wireless sensor networks when sensor nodes are deployed in areas with obstacles has resulted in numerous ingenious proposals and techniques. However, there is a lack of solutions for complicated cases wherein the source or the sink nodes are located close to a specific hole, especially in cavern-like regions of large complex-shaped holes. In this paper, we propose a geographic routing scheme to deal with the existence of complicated-shape holes in an effective manner. Our proposed routing scheme achieves routes around holes with the (1+$$\epsilon$$ ϵ )-stretch. Experimental results show that our routing scheme yields the highest load balancing and the most extended network lifetime compared to other well-known routing algorithms as well.

scholarly journals e-HUNSR: An Efficient Algorithm for Mining High Utility Negative Sequential Rules

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1211
Author(s):  
Mengjiao Zhang ◽  
Tiantian Xu ◽  
Zhao Li ◽  
Xiqing Han ◽  
Xiangjun Dong
Keyword(s):  
Decision Making ◽  
Real Life ◽  
The Other ◽  
Utility Value ◽  
Science Data ◽  
Related Information ◽  
Sequential Rule ◽  
Pruning Strategy ◽  
High Utility ◽  
Synthetic Datasets

As an important technology in computer science, data mining aims to mine hidden, previously unknown, and potentially valuable patterns from databases.High utility negative sequential rule (HUNSR) mining can provide more comprehensive decision-making information than high utility sequential rule (HUSR) mining by taking non-occurring events into account. HUNSR mining is much more difficult than HUSR mining because of two key intrinsic complexities. One is how to define the HUNSR mining problem and the other is how to calculate the antecedent’s local utility value in a HUNSR, a key issue in calculating the utility-confidence of the HUNSR. To address the intrinsic complexities, we propose a comprehensive algorithm called e-HUNSR and the contributions are as follows. (1) We formalize the problem of HUNSR mining by proposing a series of concepts. (2) We propose a novel data structure to store the related information of HUNSR candidate (HUNSRC) and a method to efficiently calculate the local utility value and utility of HUNSRC’s antecedent. (3) We propose an efficient method to generate HUNSRC based on high utility negative sequential pattern (HUNSP) and a pruning strategy to prune meaningless HUNSRC. To the best of our knowledge, e-HUNSR is the first algorithm to efficiently mine HUNSR. The experimental results on two real-life and 12 synthetic datasets show that e-HUNSR is very efficient.

High birefringent, low loss and flattened dispersion asymmetric slotted core-based photonic crystal fiber in THz regime

2019 ◽  
Vol 33 (20) ◽  
pp. 1950218 ◽  
Author(s):  
Md. Khairum Monir ◽  
Mahmudul Hasan ◽  
Bikash Kumar Paul ◽  
Kawsar Ahmed ◽  
Hala J. El-Khozondar ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Real Life ◽  
Simulation Software ◽  
Confinement Loss ◽  
Low Loss ◽  
Material Loss ◽  
Scattering Loss ◽  
High Birefringence ◽  
Crystal Fiber

This paper proposes a novel model to attain high birefringence and low loss in a slotted core-based photonic crystal fiber (PCF) structure in THz regime. The performance of the proposed PCF has been evaluated by applying finite element method (FEM) with full simulation software COMSOL Multiphysics V-5.1. The proposed model gains good optical properties such as high birefringence of 0.24, low effective material loss (EML) of 0.03 cm[Formula: see text], low confinement loss of 6.5 × 10[Formula: see text] (dB/m), low scattering loss of 2 × 10[Formula: see text] (dB/m) and low bending loss of 7.4 × 10[Formula: see text] (dB/cm). The proposed structure also exhibits the flattened dispersion for wider frequency response. However, the real-life fabrication of the suggested model is highly feasible using the current technology due to the unique shape of circular air holes in the cladding region. The outcomes make the proposed PCF a stronger candidate for polarization-preserving applications such as sensing, communications and filtering operations in THz band.

scholarly journals Reversible image watermarking technique using LCWT and DGT

2017 ◽  
Vol 7 (1.3) ◽  
pp. 42
Author(s):  
Bennilo Fernandes.J ◽  
Sivakannan S ◽  
Prabakaran N ◽  
G. Thirugnanam
Keyword(s):  
Signal To Noise Ratio ◽  
High Reliability ◽  
Image Watermarking ◽  
Similarity Index ◽  
Effective Technique ◽  
Image Domain ◽  
Contemporary World ◽  
Related Information ◽  
Confidential Data ◽  
Reversible Image Watermarking

In this contemporary world procuring our confidential data against some unknown person is very significant. Thus to have a high reliability of data security watermarking technique is applied before transmitting the data. This proposed work LCWT and DGT decomposition gives an effective technique to protect hypertensive related information based on reversible watermarking. LCWT has the superiority of multi-resolution fundamental analysis of wavelet transform and reflects representation of image domain in LCT. And using DGT decomposition the patient information has to embed inside high frequency subband wavelet and the watermarked information will be extracted by the receiver without any loss, to reconstruct the original image information. The reliability of the proposed method is analyzed by comparing the experimental results of similarity index, normalization and peak signal to noise ratio.

Empirical investigation of wireless sensor network performance in noisy environments

2014 ◽  
Vol 12 (1) ◽  
pp. 29-38
Author(s):  
Silvanus Teneng Kiyang ◽  
Robert Van Zyl
Keyword(s):  
Ambient Noise ◽  
Network Performance ◽  
Signal To Noise Ratio ◽  
Real Life ◽  
Wireless Sensor ◽  
Mathematical Tool ◽  
Content Type ◽  
The Real ◽  
Test Platform ◽  
Set Up

Purpose – The purpose of this work is to assess the influence of ambient noise on the performance of wireless sensor networks (WSNs) empirically and, based on these findings, develop a mathematical tool to assist technicians to determine the maximum inter-node separation before deploying a new WSN. Design/methodology/approach – A WSN test platform is set up in an electromagnetically shielded environment (RF chamber) to accurately control and quantify the ambient noise level. The test platform is subsequently placed in an operational laboratory to record network performance in typical unshielded spaces. Results from the RF chamber and the real-life environments are analysed. Findings – A minimum signal-to-noise ratio (SNR) at which the network still functions was found to be of the order 30 dB. In the real-life scenarios (machines, telecommunications and computer laboratories), the measured SNR exceeded this minimum value by more than 20 dB. This is due to the low ambient industrial noise levels observed in the 2.4 GHz ISM band for typical environments found at academic institutions. It, therefore, suggests that WSNs are less prone to industrial interferences than anticipated. Originality/value – A predictive mathematical tool is developed that can be used by technicians to determine the maximum inter-node separation before the WSN is deployed. The tool yields reliable results and promises to save installation time.

A Novel Approach for Detection of Bearing Defects from Noisy Vibration Signal

2014 ◽  
Vol 592-594 ◽  
pp. 2001-2005
Author(s):  
Deepak Paliwal ◽  
Achintya Choudhury ◽  
T. Govardhan ◽  
Saurabh Singh Chandrawat
Keyword(s):  
Signal To Noise Ratio ◽  
Vibration Signal ◽  
High Background ◽  
Related Information ◽  
Bearing Defects ◽  
Novel Approach ◽  
Deep Groove ◽  
Deep Groove Ball Bearing ◽  
High Background Noise ◽  
Inner Race

Vibration signal of a defective bearing carries fault related information. The aim of this paper is to develop a signal processing methodology that identifies the presence of defect from bearing vibration signal subjected high background noise. A simulated vibration signal considering inner race defect in a deep groove ball bearing with low signal to noise ratio has been generated and investigated. A technique involving CWT of vibration signal and post-processing though FFT has been adopted to analyze the signal. Results show that proposed methodology can yield the presence of inner race defect prominently from a noisy vibration signal.

Immensely Discriminate Routing in Wireless Networks

2017 ◽  
Vol 8 (3) ◽  
pp. 712
Author(s):  
Sujatha V ◽  
E. A. Mary Anitha
Keyword(s):  
Wireless Networks ◽  
Wireless Network ◽  
Routing Protocol ◽  
Real Life ◽  
Internet Access ◽  
Multimedia Traffic ◽  
Multihop Routing ◽  
Routing Schemes ◽  
Scalable Routing

Wireless networks are predictable to grant essential Internet access multimedia traffic service also increasingly such networks have been emerged in real life. However, the application scenarios is indeterminate as well as largely scalable routing is very difficult. Thus require efficient routing schemes in wireless network. In this paper, we propose Immensely Discriminate Routing protocol is used for multihop routing in wireless network. Here, node distance, node link, node trust and node quality of service is evaluated the next hop. This parameters are determined an efficient path in the wireless network.

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