scholarly journals Ranging with Frequency Dependent Ultrasound Air Attenuation

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4963
Author(s):  
Riccardo Carotenuto ◽  
Fortunato Pezzimenti ◽  
Francesco G. Della Corte ◽  
Demetrio Iero ◽  
Massimo Merenda
Keyword(s):  
Low Cost ◽  
Ultrasonic Transducer ◽  
Reference Points ◽  
Optical Channel ◽  
Signal Attenuation ◽  
Frequency Dependent ◽  
Ultrasonic Signals ◽  
Average Value ◽  
Attenuation Level ◽  
Multiple Measurements

Measuring the distance between two points has multiple uses. Position can be geometrically calculated from multiple measurements of the distance between reference points and moving sensors. Distance measurement can be done by measuring the time of flight of an ultrasonic signal traveling from an emitter to receiving sensors. However, this requires close synchronization between the emitter and the sensors. This synchronization is usually done using a radio or optical channel, which requires additional hardware and power to operate. On the other hand, for many applications of great interest, low-cost, small, and lightweight sensors with very small batteries are required. Here, an innovative technique to measure the distance between emitter and receiver by using ultrasonic signals in air is proposed. In fact, the amount of the signal attenuation in air depends on the frequency content of the signal itself. The attenuation level that the signal undergoes at different frequencies provides information on the distance between emitter and receiver without the need for any synchronization between them. A mathematical relationship here proposed allows for estimating the distance between emitter and receiver starting from the measurement of the frequency dependent attenuation along the traveled path. The level of attenuation in the air is measured online along the operation of the proposed technique. The simulations showed that the range accuracy increases with the decrease of the ultrasonic transducer diameter. In particular, with a diameter of 0.5 mm, an error of less than ± 2.7 cm (average value 1.1 cm) is reached along two plane sections of the typical room of the office considered (4 × 4 × 3 m3).

Combining Ultrasonic Signals And Multi-Colored Images To Perform Object Tracking And Recognition In Low-Cost Robotic Platforms

2016 ◽  
Author(s):  
Danilo H. F. Menezes ◽  
Thiago D. Mendonca ◽  
Wolney M. Neto ◽  
Hendrik T. Macedo ◽  
Leonardo N. Matos
Keyword(s):  
Object Tracking ◽  
Low Cost ◽  
Ultrasonic Signals ◽  
Robotic Platforms ◽  
Tracking And Recognition

scholarly journals Determination of vertical dimension of occlusion by using the phonetic vowel "O" and "E"

2015 ◽  
Vol 72 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Marko Igic ◽  
Nebojsa Krunic ◽  
Ljiljana Aleksov ◽  
Milena Kostic ◽  
Aleksandra Igic ◽  
...  
Keyword(s):  
Cognitive Functions ◽  
Complete Denture ◽  
Reference Points ◽  
Vertical Dimension ◽  
Entire Sample ◽  
Average Value ◽  
Significant Difference ◽  
The Relationship

Background/Aim. The vertical dimension of occlusion is a very important parameter for proper reconstruction of the relationship between the jaws. The literature describes many methods for its finding, from the simple, easily applicable clinically, to quite complicated, with the use of one or more devices for determination. The aim of this study was to examine the possibility of determining the vertical dimension of occlusion using the vocals ?O? and ?E? with the control of values o btained by applying cognitive functions. Methods. This investigation was performed with the two groups of patients. The first group consisted of 50 females and 50 males, aged 18 to 30 years. In this group the distance between the reference points (on top of the nose and chin) was measured in the position of the mandible in the vertical dimension of occlusion, the vertical dimension at rest and the pronunciation of the words ?OLO? and ?ELE?. Checking the correctness of the particular value for the word ?OLO? was also performed by the phonetic method with the application of cognitive exercises when the patients counted from 89 to 80. The obtained difference in the average values i n determining the vertical dimension of occlusion and the ?OLO? and ?ELE? in the first group was used as the reference for determining the vertical dimension of occlusion in the second group of patients. The second group comprised of 31 edentulous persons (14 females and 17 males), aged from 54 to 85 years who had been made a complete denture. Results. The average value obtained for the vertical dimension of rest for the entire sample was 2.16 mm, for the word ?OLO? for the entire sample was 5.51 mm and for the word ?ELE? for the entire sample was 7.47 mm. There was no statistically significant difference between the genders for the value of the vertical dimension at rest, ?ELE? and ?OLO?. There was a statistically significant difference between the values f or the vertical dimension at rest, ?OLO? and ?ELE? for both genders. There was a statistically significant correlation between the value for the vertical dimension at rest, ?OLO? and ?ELE?, for both groups of subjects. Conclusion. Determining the vertical dimension of occlusion requires 5.5 mm subtraction from the position of the mandible in pronunciation of the word ?OLO? or 7.5 mm in pronunciation of the word ?ELE?.

scholarly journals Including frequency-dependent attenuation for the deconvolution of ultrasonic signals

2013 ◽  
Vol 133 (5) ◽  
pp. 3299-3299 ◽  
Author(s):  
Ewen Carcreff ◽  
Sébastien Bourguignon ◽  
Jérôme Idier ◽  
Laurent Simon
Keyword(s):  
Frequency Dependent ◽  
Ultrasonic Signals

An Active and Low-Cost Microwave Imaging System design for Detection of Breast Cancer Using Back Scattered Signal

2021 ◽  
Vol 17 ◽  
Author(s):  
Anupma Gupta ◽  
Paras Chawla ◽  
Ankush Kansal ◽  
Kulbir Singh
Keyword(s):  
Breast Tissue ◽  
Imaging System ◽  
Low Cost ◽  
Wide Band ◽  
Breast Tumour ◽  
Remarkable Effect ◽  
Average Value ◽  
Antenna Performance ◽  
Tumour Diagnosis ◽  
High Dielectric

: A defected ground antenna with dielectric reflector is designed and investigated for breast tumour diagnosis. Ultra-wide band resonance (3.1 to 10.6 GHz) is achieved by etching two slots and adding a narrow vertical strip in a patch antenna. A high dielectric constant substrate is added below the antenna, which shows remarkable effect on performance. Antenna performance is verified experimentally on an artificially fabricated breast tissue and tumour. Malignant tissue has different dielectric properties than the normal tissue, that causes deviation in the scattered antenna power. Average value of backscattered signal variation and ground penetrating radar (GPR) algorithm is used to localize the tumour of radius 4mm in breast tissue.

scholarly journals A Blind Calibration Model for I/Q Imbalances of Wideband Zero-IF Receivers

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1868
Author(s):  
Xiaoye Peng ◽  
Zhiyu Wang ◽  
Jiongjiong Mo ◽  
Chenge Wang ◽  
Jiarui Liu ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Finite Impulse Response ◽  
Low Cost ◽  
Classification Rule ◽  
Statistical Characteristics ◽  
High Signal ◽  
Calibration Model ◽  
Frequency Dependent ◽  
Frequency Independent ◽  
Blind Calibration

Frequency-dependent I/Q imbalance and frequency-independent I/Q imbalance are the major impairments in wideband zero-IF receivers, and they both cannot be ignored. In this paper, a blind calibration model is designed for compensating these I/Q imbalances. In order to accurately estimate the imbalance parameters with low cost, a classification rule is proposed according to the frequency-domain statistical characteristics of the received signal. The calibration points in the frequency-domain are divided into two groups. Then, the amplitude imbalance and the frequency-dependent phase imbalance are derived from the group of signal points and, separately, the frequency-independent phase imbalance is calculated from the group of noise points. In the derivation of the frequency-dependent phase imbalance, a general fitting model suitable for all signal points is proposed, which does not require special calculations for either DC point or fs/2 point. Then, a finite impulse response (FIR) real-valued filter is designed to correct the impairments of received signal. The performances of the proposed calibration model are evaluated through both simulations and experiments. The simulation results show the image rejection ratio (IRR) improvement to around 35–45 dBc at high signal-to-noise ratio (SNR). Based on the mismatched data of the ADRV9009 evaluation board, the experimental results exhibit the IRR improvement of both multi-tone and wideband signals to about 30 dBc.

scholarly journals Including frequency-dependent attenuation for the deconvolution of ultrasonic signals

2013 ◽  
Author(s):  
Ewen Carcreff ◽  
Sébastien Bourguignon ◽  
Jéro^me Idier ◽  
Laurent Simon ◽  
Aroune Duclos
Keyword(s):  
Frequency Dependent ◽  
Ultrasonic Signals

Localization of Distributed Wireless Sensor Networks using Two Sage SDP Optimization

2017 ◽  
Vol 7 (3) ◽  
pp. 1255
Author(s):  
Reza Shahbazian ◽  
Seyed Ali Ghorashi
Keyword(s):  
Optimization Problem ◽  
Low Cost ◽  
Reference Points ◽  
Wireless Sensor ◽  
Relaxation Techniques ◽  
Problem Size ◽  
Distance Measurements ◽  
Localization Accuracy ◽  
Positioning Systems ◽  
Cost Efficient

<span class="fontstyle0">A wireless sensor network (WSN) may comprise a large distributed set of low cost, low power sensing nodes. In many applications, the location of sensors is a necessity to evaluate the sensed data and it is not energy and cost efficient to equip all sensors with global positioning systems such as GPS. In this paper, we focus on the localization of sensors in a WSN by solving an optimization problem. In WSN localization, some sensors (called anchors) are aware of their location. Then, the distance measurements between sensors and anchors locations are used to localize the whole sensors in the network. WSN localization is a non-convex optimization problem, however, relaxation techniques such as semi-definite programming (SDP) are used to relax the optimization. To solve the optimization problem, all constraints should be considered simultaneously and the solution complexity order is O(n2) </span><span class="fontstyle0">where </span><span class="fontstyle2">n </span><span class="fontstyle0">is the number of sensors. The complexity of SDP prevents solving large size problems. Therefore, it would be beneficial to reduce the problem size in large and distributed WSNs. In this paper, we propose a two stage optimization to reduce the solution time, while provide better accuracy compared with original SDP method. We first select some sensors that have the maximum connection with anchors and perform the SDP localization. Then, we select some of these sensors as virtual anchors. By adding the virtual anchors, we add more reference points and decrease the number of constraints. We propose an algorithm to select and add virtual anchors so that the total solution complexity and time decrease considerably, while improving the localization accuracy.</span>

scholarly journals Comparison of the Microwave Absorption Properties of Opuntia ficus-indica, Agave atrovirens, and Cocos nucifera L. Husk

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Jorge Simón ◽  
J. Villanueva-Maldonado ◽  
Francisco R. Castillo-Soria ◽  
Marco Cardenas-Juarez ◽  
Edgar Briones ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Microwave Absorption ◽  
Low Cost ◽  
Cocos Nucifera ◽  
Agricultural Waste ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Opuntia Ficus Indica ◽  
Average Value ◽  
Cocos Nucifera L

In this work, a comparison of the microwave absorption properties of Opuntia ficus-indica cladodes, Agave atrovirens branches, and Cocos nucifera L. husk samples was performed. The study was carried out by inserting dry and powdered samples of these organic materials transversely and in the middle of a rectangular waveguide, for which scattering parameters S21 and S11 were measured to estimate the absorption coefficient. These measurements were compared to determine the material that behaves the best as a microwave absorber with a view to develop future low-cost and eco-friendly products by reusing agricultural waste. Specifically, Agave atrovirens sample showed the best performance, having an average value of absorption coefficient of 0.4218, while its maximum was 0.5792 at 9.706 GHz within the range from 8.005 to 13 GHz.

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