Optimizing Volumetric Efficiency and Backscatter Communication in Biosensing Ultrasonic Implants

2020 ◽  
Vol 14 (6) ◽  
pp. 1381-1392
Author(s):  
Mohammad Meraj Ghanbari ◽  
Rikky Muller
Keyword(s):  
Volumetric Efficiency ◽  
Backscatter Communication

Energy-efficient UAV trajectory design for backscatter communication: A deep reinforcement learning approach

2020 ◽  
Vol 17 (10) ◽  
pp. 129-141
Author(s):  
Yiwen Nie ◽  
Junhui Zhao ◽  
Jun Liu ◽  
Jing Jiang ◽  
Ruijin Ding
Keyword(s):  
Reinforcement Learning ◽  
Energy Efficient ◽  
Learning Approach ◽  
Trajectory Design ◽  
Backscatter Communication

scholarly journals Multi-Filter Decoding in WiFi Backscatter Communication

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1481
Author(s):  
Richard Boateng Nti ◽  
Ji-Hoon Yun
Keyword(s):  
Wireless Sensor Network ◽  
Internet Of Things ◽  
Filter Design ◽  
Wireless Sensor ◽  
Noise Interference ◽  
Decoding Algorithms ◽  
Backscatter Communication ◽  
Wide Range ◽  
Testbed Experiments ◽  
Backscattered Signals

WiFi backscatter communication has emerged as a promising enabler of ultralow-power connectivity for Internet of things, wireless sensor network and smart energy. In this paper, we propose a multi-filter design for effective decoding of WiFi backscattered signals. Backscattered signals are relatively weak compared to carrier WiFi signals and therefore require algorithms that filter out original WiFi signals without affecting the backscattered signals. Two multi-filter designs for WiFi backscatter decoding are presented: the summation and delimiter approaches. Both implementations employ the use of additional filters with different window sizes to efficiently cut off undesired noise/interference, thus enhancing frame detection and decoding performance, and can be coupled with a wide range of decoding algorithms. The designs are particularly productive in the frequency-shift WiFi backscatter communication. We demonstrate via prototyping and testbed experiments that the proposed design enhances the performance of various decoding algorithms in real environments.

scholarly journals A Physical Layer Security Enhancement Scheme under the Ambient Backscatter System

Symmetry ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Pengfei Hou ◽  
Jianping Gong ◽  
Jumin Zhao
Keyword(s):  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Physical Layer Security ◽  
Physical Layer ◽  
Artificial Noise ◽  
Identification System ◽  
Secrecy Rate ◽  
Channel Quality ◽  
Backscatter Communication ◽  
Ambient Backscatter

In this paper, we proposed a scheme that Injects artificial noise from the tag end (IANT) to enhance the physical layer security of the ambient backscatter communication (ABC) system. The difference between the ABC system and the traditional radio frequency identification system is whether it uses the radio frequency (RF) signals in the environment to supply energy and modulation information for passive tags. In the IANT scheme, we select the best tag to communicate with the reader according to the channel quality between tags and reader, and at the same time select another tag to generate artificial noise that affects the receiving effect of the eavesdropper. This paper uses the method of generating noise copies in the reader to reduce the interference of artificial noise on the signal received by the reader. The simulation results show that with the increase in channel quality between tags and reader and the increase in the number of tags, the proposed IANT scheme is significantly superior to the contrast scheme in terms of system achievable secrecy rate, effectively enhancing the physical layer security of the ABC system.

Light-duty single and multi-shaft boosting and compounding studies with in-cylinder insulation

2020 ◽  
pp. 146808742098058
Author(s):  
Peter Andruskiewicz ◽  
Russell Durrett ◽  
Venkatesh Gopalakrishnan ◽  
Kushal Narayanaswamy ◽  
Paul Najt
Keyword(s):  
Engine Performance ◽  
Volumetric Efficiency ◽  
Expansion Process ◽  
Exhaust Gases ◽  
Positive Displacement ◽  
Brake Power ◽  
Light Duty ◽  
Insight Into

A set of two-cylinder engine concepts utilizing a supercharger and piston- or turbine-compounding were compared to a turbocharged engine modeled with a consistent methodology developed in previous works. In-cylinder insulation was added to each of the engines to evaluate the effects on performance. The goals of this simulation were to utilize energy that otherwise would be bypassed around the turbine side of a turbocharger and redirect it to the crankshaft, as well as to redirect energy that would previously have entered the coolant into the exhaust gases where it could be reclaimed by a second expansion process. Gains in performance and efficiency were thoroughly analyzed to provide insight into the magnitudes and mechanisms responsible. It was found that the second expansion process from exhaust-compounding was able to significantly improve engine performance at moderate to high loads, as well as compensate for the loss in volumetric efficiency that accompanies in-cylinder insulation. The piston-compounded single-shaft DCDE was able to outperform the turbocharged multi-shaft DCDE at mid to high loads, and in maximum brake power due to the low losses in the coupled nature of the second expansion, while the turbine-compounded engine suffers higher losses due to the turbomachinery mismatch with the positive displacement power cylinders.

scholarly journals Research on Cavitation of the Rotating-Sleeve Distributing Flow System Considering Different Cam Groove Profiles

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2139
Author(s):  
Shanxiao Du ◽  
Jichao Hong ◽  
Hongxin Zhang ◽  
Qinghai Zhao ◽  
Tiezhu Zhang ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Flow System ◽  
Volumetric Efficiency ◽  
Piston Pump ◽  
Operating Frequency ◽  
Cavitation Model ◽  
Pump Chamber ◽  
Orthogonal Experiments ◽  
Simulation Results ◽  
Further Development

Reciprocating piston pumps are widely used in various fields, such as automobiles, ships, aviation, and engineering machinery. Conventional reciprocating piston pump distributing flow (RPPDF) systems have the disadvantages of a loose structure and low volumetric efficiency, as well as affected positively by the operating frequency. In this paper, a novel rotating-sleeve distributing flow (RSDF) system is presented for bridging these drawbacks, as well as structurally improved to overcome the inoperable and challenging problems in oil intake and discharge found in the experiment. Moreover, the Singhal cavitation model specifically for the RSDF system and four-cam groove profiles (CGPs) is established. To find the most suitable CGP to reduce the RSDF’s cavitation, the cavitation of the RSDF system was investigated, combining with simulations by taking into account the gap among the rotating sleeve, the pump chamber, and experiments on four presented CGPs. Simulation results based on vapor volume fraction, cavitation ratio, and volumetric efficiency show that the linear profile’s cavitation is the weakest. Finally, the correctness of the simulation is verified through orthogonal experiments. This research is of great significance to the further development of the RSDF system; more important, it has great potential to promote the reform of the RPPDF method.

Exploiting Multiple Antennas for Cognitive Ambient Backscatter Communication

2019 ◽  
Vol 6 (1) ◽  
pp. 765-775 ◽  
Author(s):  
Huayan Guo ◽  
Qianqian Zhang ◽  
Sa Xiao ◽  
Ying-Chang Liang
Keyword(s):  
Multiple Antennas ◽  
Backscatter Communication ◽  
Ambient Backscatter
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