Reception of audio signals received from different LEDs used in the low cost LI-FI systems

Author(s):  
Tsvetan Valkovski ◽  
Kalin Dimitrov
Keyword(s):  
Low Cost ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 356-362
Author(s):  
Harry Coppock ◽  
Alex Gaskell ◽  
Panagiotis Tzirakis ◽  
Alice Baird ◽  
Lyn Jones ◽  
...  

BackgroundSince the emergence of COVID-19 in December 2019, multidisciplinary research teams have wrestled with how best to control the pandemic in light of its considerable physical, psychological and economic damage. Mass testing has been advocated as a potential remedy; however, mass testing using physical tests is a costly and hard-to-scale solution.MethodsThis study demonstrates the feasibility of an alternative form of COVID-19 detection, harnessing digital technology through the use of audio biomarkers and deep learning. Specifically, we show that a deep neural network based model can be trained to detect symptomatic and asymptomatic COVID-19 cases using breath and cough audio recordings.ResultsOur model, a custom convolutional neural network, demonstrates strong empirical performance on a data set consisting of 355 crowdsourced participants, achieving an area under the curve of the receiver operating characteristics of 0.846 on the task of COVID-19 classification.ConclusionThis study offers a proof of concept for diagnosing COVID-19 using cough and breath audio signals and motivates a comprehensive follow-up research study on a wider data sample, given the evident advantages of a low-cost, highly scalable digital COVID-19 diagnostic tool.


2021 ◽  
Vol 20 ◽  
pp. 176-181
Author(s):  
Debalina Banerjee ◽  
Akashjyoti Banik ◽  
Sanjib Kumar Singh ◽  
Kandarpa Kumar Sarma

Surveillance operations designed to be carried out by a robotic vehicle for entry into an area of higher risks and perform hazardous tasks form the core of this work. The system is integrated with a robotic vehicle that is controlled through a virtual interface and well supported by live video streaming. Here, the motion detection sensor is used as a simple but powerful human presence detector and alarm trigger. Also, the design has a metal detector and gas detecting sensor that can provide precaution against potential landmines present in the operations area and presence of chemicals, high energy materials or poisonous gases on regular and event-based occurrence. The real-time data of the gas sensor is stored in the local machine and also uses a speech recognition system developed using Raspberry Pi microcomputer to detect audio signals. It generates routine alarms on special/unknown/ first time patterns of audio threats. The system is designed using low-cost components.


2021 ◽  
Author(s):  
Md Zakir Hossain ◽  
Md. Bashir Uddin ◽  
Khandaker Asif Ahmed

AbstractThe COVID-19 pandemic has a devastating impact on the health and well-being of global population. Cough audio signals classification showed potential as a screening approach for diagnosing people, infected with COVID-19. Recent approaches need costly deep learning algorithms or sophisticated methods to extract informative features from cough audio signals. In this paper, we propose a low-cost envelope approach, called CovidEnvelope, which can classify COVID-19 positive and negative cases from raw data by avoiding above disadvantages. This automated approach can pre-process cough audio signals by filter-out back-ground noises, generate an envelope around the audio signal, and finally provide outcomes by computing area enclosed by the envelope. It has been seen that reliable datasets are also important for achieving high performance. Our approach proves that human verbal confirmation is not a reliable source of information. Finally, the approach reaches highest sensitivity, specificity, accuracy, and AUC of 0.92, 0.87, 0.89, and 0.89 respectively. The automatic approach only takes 1.8 to 3.9 minutes to compute these performances. Overall, this approach is fast and sensitive to diagnose the people living with COVID-19, regardless of having COVID-19 related symptoms or not, and thus have vast applicability in human well-being by designing HCI devices incorporating this approach.


Author(s):  
Steven Bergren ◽  
Carl D. Latino ◽  
Christopher A. Varnon ◽  
Charles I. Abramson

The purpose of this project was to create a device to detect infrasound communication from elephants. The device was designed and prototyped to be capable of monitoring an input signal for infrasound. If infrasound is detected, an audible alarm is sounded. This device can record audio signals for long periods of time to a digital storage device. It can be utilized for other areas of study with some modification. For example, by selecting appropriate sensors the device can be used for studying vibrations in structures. The device is low-cost so it would be able to be procured more easily and in higher quantities than more expensive and cumbersome laboratory monitoring equipment. This device could also be used as an educational and research device for students studying animal behavior in the field and laboratory. Infrasound is not limited to only elephants, but hippopotamuses, rhinoceroses and giraffes also communicate with infrasound. Environmental infrasound from sources such as wind turbines, sonic booms, explosions, tornadoes, and earthquakes can also be monitored.


Author(s):  
Mr. Sachin Tyagi

People with visual impairments often depend on outside help that can be provided by the following agencies Humans, well-trained dogs, or special electronic devices are used as decision support systems. Principal The problem for blind people is how to navigate where they want to go. Those people need Help from other people with good eyesight. As described by the World Health Organization, 10% of people with visual impairment have There is no functional vision to help them move safely without assistance. This article is Designed to help blind people overcome visual defects through the use of other senses, such as sound and Touch. The system uses the Atmega328 microcontroller, which is a high performance 8-bit AVR RISC microcontroller. To detect the distance, the system uses HCSR04, an ultrasonic range Finder distance sensor module. The sensor module is designed to use sensors to measure distance The SONAR or RADAR principle uses ultrasound to determine the distance of an object. This The system also includes a buzzer that generates an alarm sound and a motor that generates vibration. Sign. The system uses audio and vibration signals to notify users of upcoming obstacles. What The distance between the glove and the obstacle, the frequency of the audio signals and vibration is reduced Increase. Therefore, the system helps to simplify the navigation process for those who need it. The system provides a Low-cost, reliable, portable, energy-efficient and powerful navigation solutions Response time is short.


Author(s):  
Y. L. Chen ◽  
S. Fujlshiro

Metastable beta titanium alloys have been known to have numerous advantages such as cold formability, high strength, good fracture resistance, deep hardenability, and cost effectiveness. Very high strength is obtainable by precipitation of the hexagonal alpha phase in a bcc beta matrix in these alloys. Precipitation hardening in the metastable beta alloys may also result from the formation of transition phases such as omega phase. Ti-15-3 (Ti-15V- 3Cr-3Al-3Sn) has been developed recently by TIMET and USAF for low cost sheet metal applications. The purpose of the present study was to examine the aging characteristics in this alloy.The composition of the as-received material is: 14.7 V, 3.14 Cr, 3.05 Al, 2.26 Sn, and 0.145 Fe. The beta transus temperature as determined by optical metallographic method was about 770°C. Specimen coupons were prepared from a mill-annealed 1.2 mm thick sheet, and solution treated at 827°C for 2 hr in argon, then water quenched. Aging was also done in argon at temperatures ranging from 316 to 616°C for various times.


Author(s):  
J. D. Muzzy ◽  
R. D. Hester ◽  
J. L. Hubbard

Polyethylene is one of the most important plastics produced today because of its good physical properties, ease of fabrication and low cost. Studies to improve the properties of polyethylene are leading to an understanding of its crystalline morphology. Polyethylene crystallized by evaporation from dilute solutions consists of thin crystals called lamellae. The polyethylene molecules are parallel to the thickness of the lamellae and are folded since the thickness of the lamellae is much less than the molecular length. This lamellar texture persists in less perfect form in polyethylene crystallized from the melt.Morphological studies of melt crystallized polyethylene have been limited due to the difficulty of isolating the microstructure from the bulk specimen without destroying or deforming it.


Author(s):  
J. Temple Black

In ultramicrotomy, the two basic tool materials are glass and diamond. Glass because of its low cost and ease of manufacture of the knife itself is still widely used despite the superiority of diamond knives in many applications. Both kinds of knives produce plastic deformation in the microtomed section due to the nature of the cutting process and microscopic chips in the edge of the knife. Because glass has no well defined slip planes in its structure (it's an amorphous material), it is very strong and essentially never fails in compression. However, surface flaws produce stress concentrations which reduce the strength of glass to 10,000 to 20,000 psi from its theoretical or flaw free values of 1 to 2 million psi. While the microchips in the edge of the glass or diamond knife are generally too small to be observed in the SEM, the second common type of defect can be identified. This is the striations (also termed the check marks or feathers) which are always present over the entire edge of a glass knife regardless of whether or not they are visable under optical inspection. These steps in the cutting edge can be observed in the SEM by proper preparation of carefully broken knives and orientation of the knife, with respect to the scanning beam.


Author(s):  
H. O. Colijn

Many labs today wish to transfer data between their EDS systems and their existing PCs and minicomputers. Our lab has implemented SpectraPlot, a low- cost PC-based system to allow offline examination and plotting of spectra. We adopted this system in order to make more efficient use of our microscopes and EDS consoles, to provide hardcopy output for an older EDS system, and to allow students to access their data after leaving the university.As shown in Fig. 1, we have three EDS systems (one of which is located in another building) which can store data on 8 inch RT-11 floppy disks. We transfer data from these systems to a DEC MINC computer using “SneakerNet”, which consists of putting on a pair of sneakers and running down the hall. We then use the Hermit file transfer program to download the data files with error checking from the MINC to the PC.


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