scholarly journals Design and Performance Analysis of Compact Wearable Textile Antennas for IoT and Body-Centric Communication Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-12 ◽  
Author(s):  
Sanjit Varma ◽  
Somia Sharma ◽  
Merbin John ◽  
Richa Bharadwaj ◽  
Anuj Dhawan ◽  
...  
Keyword(s):  
Radiation Pattern ◽  
Free Space ◽  
Human Subject ◽  
Indoor Environment ◽  
Return Loss ◽  
Structure Design ◽  
Indoor Environments ◽  
Performance Analyses ◽  
And Performance ◽  
Loop Antennas

This paper presents two compact textile-based planar dipole and loop antennas for wearable communication applications operating in the 2.4 GHz industrial, scientific, and medical radio (ISM) bands. The antennas were fabricated on a 0.44 mm thin camouflaged-military print, cotton jean cloth using conductive copper threads, and sewing embroidery technique to create the radiating structure. Design and performance analyses of the antennas were carried out using simulations; further experiments were performed in anechoic chamber and indoor environment to validate the designs. The experiments were carried out in a free space scenario and on the various locations of the human subject such as the torso and limb joints. The performance of the antennas was investigated based on the reflection coefficient in normal and bent conditions corresponding to the different radii of the locations of the human limbs. The antennas perform well in free space and on-body scenarios in flat and bend conditions providing return loss below −10 dB in all cases with an acceptable resonant frequency close to 2.4 GHz due to the antenna bending and body effects. The radiation pattern measurements are also reported in this work for free space and on-body scenarios. It is observed that the presence of the human body significantly influences the antenna radiation pattern which leads to an increase in the front-to-back ratio and also makes the antenna more directive. Overall, the performance of the fabricated embroidered textile antennas was found suitable for various wearable body-centric applications in indoor environments.

scholarly journals Human response to the thermal indoor environment created by a radiant, and a combined radiant and convective cooling system

2019 ◽  
Vol 111 ◽  
pp. 02060
Author(s):  
Ongun B. Kazanci ◽  
Dolaana Khovalyg ◽  
Takayoshi Iida ◽  
Yoshitaka Uno ◽  
Tomo-oki Ukiana ◽  
...  
Keyword(s):  
Human Subject ◽  
Indoor Environment ◽  
Cooling System ◽  
Human Subjects ◽  
Whole Body ◽  
Indoor Environments ◽  
Climate Chamber ◽  
Convective Cooling ◽  
Physical Measurements ◽  
Two Systems

This study reports the main findings from a series of human subject experiments, where the subjects were exposed to the different indoor environments created by different cooling systems. The studied systems were a radiant cooling system (chilled ceiling and mixing ventilation, CCMV), and a combined radiant and convective cooling system (radiant diffuse ceiling ventilation, RDCV). The experiments were conducted in a climate chamber under controlled conditions. The climate chamber was configured as a two-person office room. 24 human subjects (12 female and 12 male) were chosen. The exposure lasted three hours and the participants were allowed to work on their own tasks (normal office work) during the exposure. The cooling load was 54 W/m2 and the room temperature at a reference location was kept constant at 26°C (summer conditions). The results show that under both systems, whole body thermal sensation was between slightly warm and neutral (closer to neutral with the RDCV system), and the overall thermal acceptability was almost the same for both systems (close to clearly acceptable). The satisfaction of the human subjects with the thermal environment was very close under the two systems; between satisfactory and slightly satisfactory (closer to satisfactory). Air movement acceptability (slightly higher and closer to clearly acceptable with the RDCV system) was also very close with the two systems. The results of the human subject experiments agree well with the physical measurements of the thermal indoor environment and confirm that the studied systems created very similar thermal indoor environments.

scholarly journals Portable UWB based Monopole Antenna for Wearable Applications

2019 ◽  
Vol 8 (2) ◽  
pp. 71-75
Keyword(s):  
Radiation Pattern ◽  
Free Space ◽  
Return Loss ◽  
Monopole Antenna ◽  
Uwb Antenna ◽  
Input Matching

A planar UWB antenna is intended to deploy for on-body applications. The antenna is typically to manage for free space and placed on a harmonized phantom. The calculations are performed for return loss, radiation pattern and gain. The performance of the UWB antenna ranges from 3-11.2GHz. The main feature of the antenna depicts superior impedance level with good satisfaction on on-body propagation. Here, the observation between the phantom and antenna are carried out which results in input matching of the proposed antenna. The return losses are very slightly affected but the Gain of the antenna is seen decreasing significantly, after placing the antenna on the phantom.

Study on the Temperature and Humidity Control Performance of Hwang-Toh Finish

2012 ◽  
Vol 204-208 ◽  
pp. 3652-3659 ◽  
Author(s):  
Kyuin Lee ◽  
Dong Woo Yeom ◽  
Byeon Gho Lee
Keyword(s):  
Indoor Environment ◽  
Full Scale ◽  
The Other ◽  
Performance Evaluations ◽  
Indoor Environments ◽  
Control Performance ◽  
Humidity Control ◽  
Temperature And Humidity ◽  
And Performance

This research tried to analyze the effects of ecological materials on indoor environments. For this purpose, two full scale mock-ups were constructed: one with silk wall paper, which is generally used for indoor finishing and the other with hwang-toh (yellow soil), which is the preferred material for wall finishing. Comparison and performance evaluations were conducted, and the effects of hwang-toh finishing on a humid indoor environment were verified. Through this research, it was verified that a hwang-toh plaster finish is effective in maintaining the comfort of an indoor environment

scholarly journals A review of total volume environment and individually controlled micro-environment

2019 ◽  
Vol 111 ◽  
pp. 02002
Author(s):  
Weixin Zhao ◽  
Risto Kosonen ◽  
Simo Kilpeläinen ◽  
Sami Lestinen
Keyword(s):  
Indoor Environment ◽  
Energy Use ◽  
Indoor Environments ◽  
High Quality ◽  
Volume Ventilation ◽  
Long Time ◽  
Clean Air ◽  
And Performance ◽  
Personalized Ventilation ◽  
Assessment Procedures

Indoor environment has great effects on the health, comfort, and performance of occupants in modern buildings. The energy used for ventilating of buildings is substantial. However, ventilation based on total volume air distribution in spaces is not always an energy efficient way to provide high-quality indoor environments. Recently, individually controlled ventilation, which is designed to supply clean air where, when, and as much as needed, makes it possible to efficiently achieve high-quality indoor environment while reducing energy use. The personalized solutions generate a micro-environment that covers the space where the user spends a relatively long time. This review based on a number of experimental and numerical studies on total volume ventilation, zonal ventilation and personalized ventilation to assess the most suitable methods for indoor environment. Performance in terms of thermal comfort, air quality and energy efficiency are examined. In this study, different ventilation systems are classified according to specific requirements and assessment procedures. Finally, a discussion on the application and benefits of these ventilation is conducted and gives a direction for further investigation. The analysis results form a basic framework regarding the application of personalized ventilation in future.

scholarly journals Performance Evaluation of Particulate Matter and Indoor Microclimate Monitors in University Classrooms under COVID-19 Restrictions

2021 ◽  
Vol 18 (14) ◽  
pp. 7363
Author(s):  
Laurentiu Predescu ◽  
Daniel Dunea
Keyword(s):  
Performance Evaluation ◽  
Particulate Matter ◽  
Air Quality ◽  
Indoor Environment ◽  
Indoor Environments ◽  
University Campus ◽  
Particle Counter ◽  
Thermal Environments ◽  
University Classrooms ◽  
Academic Personnel

Optical monitors have proven their versatility into the studies of air quality in the workplace and indoor environments. The current study aimed to perform a screening of the indoor environment regarding the presence of various fractions of particulate matter (PM) and the specific thermal microclimate in a classroom occupied with students in March 2019 (before COVID-19 pandemic) and in March 2021 (during pandemic) at Valahia University Campus, Targoviste, Romania. The objectives were to assess the potential exposure of students and academic personnel to PM and to observe the performances of various sensors and monitors (particle counter, PM monitors, and indoor microclimate sensors). PM1 ranged between 29 and 41 μg m−3 and PM10 ranged between 30 and 42 μg m−3. It was observed that the particles belonged mostly to fine and submicrometric fractions in acceptable thermal environments according to the PPD and PMV indices. The particle counter recorded preponderantly 0.3, 0.5, and 1.0 micron categories. The average acute dose rate was estimated as 6.58 × 10−4 mg/kg-day (CV = 14.3%) for the 20–40 years range. Wearing masks may influence the indoor microclimate and PM levels but additional experiments should be performed at a finer scale.

Performance analysis of WDM free space optics transmission system using MIMO technique under various atmospheric conditions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kavitha Thandapani ◽  
Maheswaran Gopalswamy ◽  
Sravani Jagarlamudi ◽  
Naveen Babu Sriram
Keyword(s):  
Wavelength Division Multiplexing ◽  
Free Space ◽  
Multiple Input Multiple Output ◽  
Atmospheric Conditions ◽  
Free Space Optical ◽  
Wavelength Division ◽  
Space Optics ◽  
Space Optical Communication ◽  
Input Multiple Output ◽  
And Performance

Abstract Free Space Optical (FSO) communication has evolved as a feasible technique for wireless implementations which offers higher bandwidth capacities over various wavelengths and refers to the transmission of modulated visible beams through atmosphere in order to communicate. Wavelength Division Multiplexing (WDM) is a technology that multiplexes numerous carrier signals onto single fiber using nonidentical wavelengths and enables the efficiency of bandwidth and expanded data rate. Multiple Input Multiple Output (MIMO) is implemented to improve the quality and performance of free space optical communication in various atmospheric conditions. In this paper, a WDM-based FSO communication system is being implemented that benefits from MIMO which receives multiple copies of the signal at receiver that are independent and analyzed for various streams of data in MIMO i.e. 2 × 2, 4 × 4, 8 × 8. Various factors like BER, Quality Factor are analyzed for the WDM-based FSO communication with MIMO using the OptiSystem for various data streams of MIMO under different atmospheric conditions.

Structure Design for Green Building in some Residential Area in Sino-Singapore Tianjin Eco-City

2011 ◽  
Vol 71-78 ◽  
pp. 655-658
Author(s):  
Rong Qin
Keyword(s):  
Energy Saving ◽  
Indoor Environment ◽  
Residential Building ◽  
Green Building ◽  
Building Design ◽  
Residential Area ◽  
Structure Design ◽  
Green Building Design ◽  
Land Saving ◽  
Material Saving

There are six basic control items, land saving, energy saving, water saving, material saving, indoor environment and operation, among which, only material saving are related to structure design. We followed the green building design concept and the control items list in those standards during structure design of one of the residential area in Sino-Singapore Tianjin Eco-city, which consist of 15~18-story residential building connected to a large underground garage, as is shown below.

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