scholarly journals Wearable Textile Antennas with High Body-Antenna Isolation: Design, Fabrication, and Characterization Aspects

2020 ◽  
Author(s):  
Nikolay Atanasov ◽  
Gabriela Atanasova ◽  
Blagovest Atanasov
Keyword(s):  
Resonant Frequency ◽  
Human Body ◽  
Detailed Examination ◽  
Electromagnetic Properties ◽  
Trade Off ◽  
High Body ◽  
Wearable Antennas ◽  
Low Profile ◽  
Design Requirements

This chapter provides a brief overview of the types of wearable antennas with high body-antenna isolation. The main parameters and characteristics of wearable antennas and their design requirements are discussed. Next, procedures (passive and active) to test the performance of wearable antennas are presented. The electromagnetic properties of the commercially available textiles used as antenna substrates are investigated and summarized here, followed by a more detailed examination of their effects on the performance of wearable antennas with high body-antenna isolation. A trade-off between substrate electromagnetic properties and resonant frequency, bandwidth, radiation efficiency, and maximum gain is presented. Finally, a case study is presented with detailed analyses and investigations of the low-profile all-textile wearable antennas with high body-antenna isolation and low SAR. Their interaction with a semisolid homogeneous human body phantom is discussed. The simulations and experimental results from different (in free-space and on-body) scenarios are presented.

scholarly journals Compact and Low-Profile UWB Antenna Based on Graphene-Assembled Films for Wearable Applications

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2552 ◽  
Author(s):  
Ran Fang ◽  
Rongguo Song ◽  
Xin Zhao ◽  
Zhe Wang ◽  
Wei Qian ◽  
...  
Keyword(s):  
Human Body ◽  
Coplanar Waveguide ◽  
Wearable Devices ◽  
Impedance Bandwidth ◽  
Body Measurements ◽  
Uwb Antenna ◽  
Wearable Antennas ◽  
Low Profile ◽  
Close Proximity ◽  
Feeding Structure

In this article, a graphene-assembled film (GAF)-based compact and low-profile ultra-wide bandwidth (UWB) antenna is presented and tested for wearable applications. The highly conductive GAFs (~106 S/m) together with the flexible ceramic substrate ensure the flexibility and robustness of the antenna, which are two main challenges in designing wearable antennas. Two H-shaped slots are introduced on a coplanar-waveguide (CPW) feeding structure to adjust the current distribution and thus improve the antenna bandwidth. The compact GAF antenna with dimensions of 32 × 52 × 0.28 mm3 provides an impedance bandwidth of 60% (4.3–8.0 GHz) in simulation. The UWB characteristics are further confirmed by on-body measurements and show a bending insensitive bandwidth of ~67% (4.1–8.0 GHz), with the maximum gain at 7.45 GHz being 3.9 dBi and 4.1 dBi in its flat state and bent state, respectively. Our results suggest that the proposed antenna functions properly in close proximity to a human body and can sustain repetitive bending, which make it well suited for applications in wearable devices.

scholarly journals Research of Wearable Textile Antennas for WBAN Applications

2019 ◽  
Vol 8 (6S3) ◽  
pp. 1347-1351
Keyword(s):  
Resonant Frequency ◽  
Human Body ◽  
Body Area Networks ◽  
Wireless Body Area Networks ◽  
Original Position ◽  
Body Area ◽  
Textile Materials ◽  
Wearable Antennas ◽  
Recent Developments

The emergence of Wireless Body Area Networks (WBAN) in recent times has diverted the attention of most researchers towards the field of wearable antennas. The WBAN has enabled communication between different devices by placing them on human body. This work is a review which intends to disclose the recent developments in the area of wearable Textile antennas for WBAN. Further the use of different textile materials has been studied and their performances have been evaluated. The results show that use of textile materials have not only increased the efficiency but also they are very flexible and make the antenna suitable for on/off body applications such as medical and military. The properties of antennas inside human body, on human body and finally at some distance from the human body have been studied. It has been noted that as the distance between human body and antenna reduces, the properties of antenna such as efficiency, directivity and gain degrade more and more. Also the resonant frequency of antenna shifts from its original position which is a very big issue and needs to be rectified. For textile materials the shift in resonant frequency is not too much and also the degradation in other properties of antenna such as efficiency, directivity and gain are insignificant.

Developing Schedule With Linear Programming (Case Study: STTF II Project Komplek Sukamukti Banjaran)

2020 ◽  
Vol 4 (02) ◽  
pp. 34-45
Author(s):  
Naufal Dzikri Afifi ◽  
Ika Arum Puspita ◽  
Mohammad Deni Akbar
Keyword(s):  
Linear Programming ◽  
Objective Function ◽  
Project Scheduling ◽  
Time Limit ◽  
Minimum Time ◽  
Service Cost ◽  
Trade Off ◽  
Overtime Work ◽  
The Cost

Shift to The Front II Komplek Sukamukti Banjaran Project is one of the projects implemented by one of the companies engaged in telecommunications. In its implementation, each project including Shift to The Front II Komplek Sukamukti Banjaran has a time limit specified in the contract. Project scheduling is an important role in predicting both the cost and time in a project. Every project should be able to complete the project before or just in the time specified in the contract. Delay in a project can be anticipated by accelerating the duration of completion by using the crashing method with the application of linear programming. Linear programming will help iteration in the calculation of crashing because if linear programming not used, iteration will be repeated. The objective function in this scheduling is to minimize the cost. This study aims to find a trade-off between the costs and the minimum time expected to complete this project. The acceleration of the duration of this study was carried out using the addition of 4 hours of overtime work, 3 hours of overtime work, 2 hours of overtime work, and 1 hour of overtime work. The normal time for this project is 35 days with a service fee of Rp. 52,335,690. From the results of the crashing analysis, the alternative chosen is to add 1 hour of overtime to 34 days with a total service cost of Rp. 52,375,492. This acceleration will affect the entire project because there are 33 different locations worked on Shift to The Front II and if all these locations can be accelerated then the duration of completion of the entire project will be effective

Selecting packaging material for dry food products by trade‐off of sustainability and performance: A case study on cookies and milk powder

2021 ◽  
Vol 34 (5) ◽  
pp. 303-318
Author(s):  
Maarten Baele ◽  
An Vermeulen ◽  
Dimitri Adons ◽  
Roos Peeters ◽  
Angelique Vandemoortele ◽  
...  
Keyword(s):  
Milk Powder ◽  
Food Products ◽  
Packaging Material ◽  
Trade Off ◽  
Dry Food ◽  
And Performance

Exploring Effective Change Propagation in a Product Family Design

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Inayat Ullah ◽  
Dunbing Tang ◽  
Qi Wang ◽  
Leilei Yin
Keyword(s):  
Product Family ◽  
Design Structure Matrix ◽  
Change Propagation ◽  
Effective Change ◽  
Design Structure ◽  
Design Changes ◽  
Requirements Change ◽  
Change Impact ◽  
Design Requirements

Product family (PF) design is a widely used strategy in the industry, as it allows meeting diverse design requirements. Change propagation in any PF is difficult to predict. Consequently, while numerous design change management methodologies presently exist, their application is restricted to a single artifact. This issue is overcome in the present study. The proposed framework explores effective change propagation paths (CPPs) by considering the risks associated with design changes in the PF with the aim of minimizing the overall redesign cost. The propagated risk, which would result in rework, is quantified in terms of change impact and propagation likelihood. Moreover, a design structure matrix (DSM) based mathematical model and an algorithm for its implementation are proposed to investigate the change propagation across the PF. Finally, to demonstrate their effectiveness, a PF of electric kettles is examined in a case study. The study findings confirm that the proposed technique is appropriate for evaluating different CPPs in PF.

Miniaturized frequency selective surface with high angular stability

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Zain Ul Abidin ◽  
Qunsheng Cao ◽  
Gulab Shah ◽  
Zaheer Ahmed Dayo ◽  
Muhammad Ejaz
Keyword(s):  
Resonant Frequency ◽  
Electric Field Distribution ◽  
Equivalent Circuit Model ◽  
Surface Current ◽  
Frequency Selective Surface ◽  
Angular Stability ◽  
Working Mechanism ◽  
Low Profile ◽  
Simple Geometry ◽  
Frequency Selective

Abstract In this paper, a miniaturized bandstop frequency selective surface (FSS) with high angular stability is presented. Each FSS element consists of four sets each consisting eight octagonal concentric interconnected loops. The four sets are connected with each other through outermost octagonal loop. The unit size is miniaturized to 0.066 λ0 at the resonant frequency of 1.79 GHz. The proposed configuration achieves excellent angular stability (only 0.025 GHz resonant frequency deviation is observed upto 83° oblique angles). The working mechanism of FSS is explained with the help of equivalent circuit model (ECM), electric field distribution, and corresponding surface current distribution. A prototype of the designed bandstop FSS is fabricated to verify the simulated frequency response. The experimental results are consistent with the simulation results. Simple geometry, low profile, high angular stability, and compact cell size are prominent features of the proposed structure.

scholarly journals A design methodology for approximate multipliers in convolutional neural networks: A case of MNIST

2021 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
Kenta Shirane ◽  
Takahiro Yamamoto ◽  
Hiroyuki Tomiyama
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Convolutional Neural Network ◽  
Design Methodology ◽  
Critical Path ◽  
High Accuracy ◽  
Path Delay ◽  
Trade Off ◽  
Critical Path Delay

In this paper, we present a case study on approximate multipliers for MNIST Convolutional Neural Network (CNN). We apply approximate multipliers with different bit-width to the convolution layer in MNIST CNN, evaluate the accuracy of MNIST classification, and analyze the trade-off between approximate multiplier’s area, critical path delay and the accuracy. Based on the results of the evaluation and analysis, we propose a design methodology for approximate multipliers. The approximate multipliers consist of some partial products, which are carefully selected according to the CNN input. With this methodology, we further reduce the area and the delay of the multipliers with keeping high accuracy of the MNIST classification.

scholarly journals Balancing the demands of validity and reliability in practice: Case study of a changing system of primary science summative assessment

2020 ◽  
Vol 18 (2) ◽  
Author(s):  
Sarah G. Earle
Keyword(s):  
Reliability And Validity ◽  
Summative Assessment ◽  
Teacher Assessment ◽  
Primary Science ◽  
Validity And Reliability ◽  
Trade Off

Teacher summative judgements of children’s attainment in science, which are statutory at age 11 in England, require consideration of both valid sampling of the construct and reliable comparison of outcomes. In order to develop understanding of the enacted ‘trade off’ between validity and reliability, this three-year case study, within the Teacher Assessment in Primary Science (TAPS) project, was undertaken during a period of statutory assessment change in England. The case demonstrates an ongoing balancing act between the demands of reliability and validity, and resulted in the development of a teacher assessment seesaw, which provides a model for both interpreting and supporting practice, within and beyond primary science.

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