scholarly journals Human Body Model for Channel Characterization Based on Ray-Tracing

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Lei Xiong ◽  
Haiyang Miao ◽  
Zhiyi Yao
Keyword(s):  
Ray Tracing ◽  
Human Body ◽  
Path Loss ◽  
Channel Modeling ◽  
The Body ◽  
60 Ghz ◽  
Human Body Model ◽  
Body Model ◽  
Measurement Results ◽  
Good Agreement

The propagation channel around human body will fluctuate due to the body effects, so it is essential to investigate the body channel. As an important method of channel modeling, ray-tracing (RT) is affected by the human body model. In this paper, a realistic human body is modeled with the idea of greedy algorithm. Based on the RT simulation and measurement results of path loss (PL), we derive the approximate shapes of the torso, head, arms, and legs, and propose a reference human body model whose credibility and accuracy have been verified at 2.4 GHz and 60 GHz. These results prove that the simulation results based on the reference human body model are in good agreement with the measurement values. In addition, the reference human body model can be adjusted according to the realistic dimension data of body.

A New Method to Concentrate Electromagnetic Field Within ROI Using a High Dielectric Material in 3T Body MRI

2013 ◽  
Author(s):  
Bu S. Park ◽  
Sunder S. Rajan ◽  
Leonardo M. Angelone
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Field ◽  
Human Body ◽  
Region Of Interest ◽  
Dielectric Materials ◽  
The Body ◽  
Human Body Model ◽  
Body Model ◽  
Simulation Results ◽  
High Dielectric

We present numerical simulation results showing that high dielectric materials (HDMs) when placed between the human body model and the body coil significantly alter the electromagnetic field inside the body. The numerical simulation results show that the electromagnetic field (E, B, and SAR) within a region of interest (ROI) is concentrated (increased). In addition, the average electromagnetic fields decreased significantly outside the region of interest. The calculation results using a human body model and HDM of Barium Strontium Titanate (BST) show that the mean local SAR was decreased by about 56% (i.e., 18.7 vs. 8.2 W/kg) within the body model.

The Key Role of Headrest Optimization in Driver Comfort

2019 ◽  
Vol 24 (3) ◽  
pp. 592-599
Author(s):  
Hamid Gheibollahi ◽  
Masoud Masih-Tehrani ◽  
Mohammadmehdi Niroobakhsh
Keyword(s):  
Human Body ◽  
The Body ◽  
Human Body Model ◽  
Sitting Posture ◽  
Conventional Vehicle ◽  
Body Model ◽  
Basic Model ◽  
Proposed Model ◽  
Stiffness And Damping

In this study, adding a headrest to the conventional vehicle driver seat is investigated to improve the driver comfort and decrease the driver damages. For this purpose, a conventional biomechanical human body model of wholebody vibrations is provided and modified by adding a head degree of freedom to the body model and a headrest to the seat model. The basic model is in the sitting posture, lumped parameters and has nine DOFs for the human body, on contrary to the proposed model which has ten DOFs. The new human body DOF is the twisting motion of the head and neck. This new DOF is generated because of headrest adding to the driver’s seat. To determine the head discomforts, the Seat to Head (STH) indexes are studied in two directions: horizontal and vertical. The Genetic Algorithm (GA) is used to optimize the STH in different directions. The optimization variables are stiffness and damping parameters of the driver’s seat which are 12 for the basic model and are 16 for a new seat. The integer programming is used for time reduction. The results show that new seat (equipped by headrest) has very better STH in both directions.

scholarly journals Novel Compact Design and Investigation of a Super Wideband Millimeter Wave Antenna for Body-Centric Communications

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
H. M. Arifur Rahman ◽  
Mohammad Monirujjaman Khan ◽  
Mohammed Baz ◽  
Mehedi Masud ◽  
Mohammed A. AlZain
Keyword(s):  
Millimeter Wave ◽  
Human Body ◽  
60 Ghz ◽  
Radiation Patterns ◽  
Human Body Model ◽  
Body Model ◽  
Wave Antenna ◽  
Band Region ◽  
Millimeter Wave Antenna ◽  
Multiple Band

This paper presents a novel design for a multiple band millimeter wave antenna with a wide active region in the extremely high frequency (EHF) range. The antenna's performance was tested at three evenly separated frequencies: 60 GHz within the V-band region, 80 GHz within the E-band region, and 100 GHz. Simulation exhibits satisfactory results in terms of gain and efficiency, although the efficiency falling tendency for higher frequency persists. As millimeter wave antennas have miniature-like dimensions and low penetration depth into human body layers, the performance of these antennas is less disturbed by the presence of a human body, making them ideal for body-centric wireless communication (BCWC) applications. Thus, a human body model was created virtually with the necessary property data. Simulations are repeated at the same frequencies as before, with the antenna kept close to the constructed human body model. The results were promising as the gains found increased radiation patterns and return loss curves remained almost identical, except some efficiencies that were considered. Some H-plane radiation patterns are changed by the presence of a human body. Although all three frequencies present satisfactory results, 60 GHz is found to be more balanced, but 100 GHz shows better gain and directivity. Multiple band operability makes this antenna suitable for various applications. Finally, a distance-based analysis was conducted to realize the in-depth characteristics of the antenna by placing the antenna at five different gaps from the human body. The result verifies the antenna’s category as suitable for body-centric communications.

scholarly journals Analysis of Human Body Shadowing Effect on Wireless Sensor Networks Operating in the 2.4 GHz Band

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3412 ◽  
Author(s):  
Łukasz Januszkiewicz
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Human Body ◽  
Path Loss ◽  
Small Region ◽  
The Body ◽  
Wireless Sensor ◽  
Indoor Environments ◽  
Human Body Model ◽  
Shadowing Effect

Miniaturized wireless sensors are designed to run on limited power resources, requiring minimization of transmit power and lowering of the fade margin in the link budget. One factor that has an important impact on wireless sensor network design is path loss between the transmitter and the receiver. This paper presents an analysis of the influence of human bodies on path loss in the 2.4 GHz band, which is commonly used for wireless sensor networks. The effect of body shadowing was first analyzed in full wave computer simulations using the finite-difference time-domain method. Due to the high numerical burden, the simulations were limited to only a small region around the human body. To analyze the performance of networks in larger indoor environments, a human body model is proposed that can be used for simulations with a ray-based computer program. The proposed model of human body is the main contribution of this paper. It was used to analyze the body shadowing effect in a typical indoor environment. The results were found to be in good agreement with measurements.

scholarly journals The Role of the Location of Personal Exposimeters on the Human Body in Their Use for Assessing Exposure to the Electromagnetic Field in the Radiofrequency Range 98–2450 MHz and Compliance Analysis: Evaluation by Virtual Measurements

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Krzysztof Gryz ◽  
Patryk Zradziński ◽  
Jolanta Karpowicz
Keyword(s):  
Human Body ◽  
Measurement Errors ◽  
The Body ◽  
Back Side ◽  
Human Body Model ◽  
Field Exposure ◽  
Limit Values ◽  
Exposure Limit ◽  
Measurement Results ◽  
Exposure Conditions

The use of radiofrequency (98–2450 MHz range) personal exposimeters to measure the electric field (E-field) in far-field exposure conditions was modelled numerically using human body model Gustav and finite integration technique software. Calculations with 256 models of exposure scenarios show that the human body has a significant influence on the results of measurements using a single body-worn exposimeter in various locations near the body ((from −96 to +133)%, measurement errors with respect to the unperturbedE-field value). When an exposure assessment involves the exposure limitations provided for the strength of an unperturbedE-field. To improve the application of exposimeters in compliance tests, such discrepancies in the results of measurements by a body-worn exposimeter may be compensated by using of a correction factor applied to the measurement results or alternatively to the exposure limit values. The location of a single exposimeter on the waist to the back side of the human body or on the front of the chest reduces the range of exposure assessments uncertainty (covering various exposure conditions). However, still the uncertainty of exposure assessments using a single exposimeter remains significantly higher than the assessment of the unperturbedE-field using spot measurements.

A generic method of wearable items virtual try-on

2020 ◽  
Vol 90 (19-20) ◽  
pp. 2161-2174
Author(s):  
Pengpeng Hu ◽  
Nastaran Nourbakhsh ◽  
Jing Tian ◽  
Stephan Sturges ◽  
Vasile Dadarlat ◽  
...  
Keyword(s):  
Motion Capture ◽  
Human Body ◽  
The Body ◽  
Motion Capture Data ◽  
Automatic Method ◽  
Human Body Model ◽  
Body Model ◽  
Fully Automatic ◽  
Reference Body ◽  
General Method

Virtual try-on synthesizes garments for the target bodies in 2D/3D domains. Even though existing virtual try-on methods focus on redressing garments, the virtual try-on hair, shoes and wearable accessories are still under-reached. In this paper, we present the first general method for virtual try-ons that is fully automatic and suitable for many items including garments, hair, shoes, watches, necklaces, hats, and so on. Starting with the pre-defined wearable items on a reference human body model, an automatic method is proposed to deform the reference body mesh to fit a target body for obtaining dense triangle correspondences. Then, an improved fit metric is used to represent the interaction between wearable items and the body. For the next step, with the help of triangle correspondences and the fit metric, the wearable items can be fast and efficiently inferred by the shape and posture of the targeted body. Extensive experimental results show that, besides automation and efficiency, the proposed method can be easily extended to implement the dynamic try-on by applying rigging and importing motion capture data, being able to handle both tight and loose garments, and even multi-layer clothing.

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