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A ground station antenna system features a conical horn attached to a microstrip antenna as an alternate receiving feed antenna. The proposed microstrip antenna has circular polarization and operates in the X-band. The far-field parameters of the antenna are measured after developing and simulating the combination of a conical horn and a microstrip antenna. The modeling results for a microstrip antenna with a conical horn offer a working bandwidth of 930 MHz, spanning frequencies 7.44 GHz to 8.37 GHz. The axial ratio measurements for a microstrip antenna joined with a conical horn produce a working bandwidth of 150 MHz, covering frequencies ranging from 7.72 GHz to 7.87 GHz. The conical horn is attached to a microstrip antenna and has a gain of 15.1 dB. The proposed antenna is designed to meet ground station antenna requirements by pairing it with a parabolic reflector with a diameter of 3.7 meters. The primary focus antenna of the proposed design was chosen. The feed antenna and parabolic reflector should be positioned at a focus point distance of 1110 mm for a total gain of 38.9 dB at 7.8 GHz frequency. The proposed antenna can be applied on X-band remote sensing ground stations as a receiving antenna. [ABSTRACT FROM AUTHOR]

Concentrated photovoltaic thermal (CPVT) systems involving parabolic reflector have been scrutinized in this article. The purpose of using such a concentrated solar system is achieving higher electrical power and greater thermal productivity. The configuration of cooling system is very significant part of designing such CPVT system, and three configurations were utilized in this numerical modeling: (1) smooth duct (case I); (2) sinusoidal duct (case II); and (3) sinusoidal duct equipped with sinusoidal fins (case III). The utilized testing fluid was a mixture of water and hybrid nanoparticles, and homogeneous formulation was utilized for finding the properties of nanomaterial. Two steps for simulations have been considered: (1) finding the distribution of heat flux involving pure radiation within two-dimensional domains and (2) three-dimensional laminar flow of hybrid nanofluid involving all layers of PV. Active variables of present modeling were: concentration of hybrid additives (ϕ = 0, 0.04), amplitude (a = 1, 2 and 4 cm) and pitch ratio (λ = 0, 4 and 16 mm) of sinusoidal duct; number of fins (NoF = 1, 3); inlet flow rate (Q = 1, 2, 3 L min−1). When sinusoidal duct has been applied in the absence of helical fin, the electrical efficacy elevates about 2.5% with inclusion of hybrid nanomaterial when a = 1 cm and λ = 4 mm. With switching from case I to case II, thermal efficiency augments about 3.5%. In view of overall efficacy, case III has the best performance among various scrutinized configurations. If the third configuration has been utilized, applying more fins makes ηth and ηele increase about 0.5% and 0.8, respectively. Increase in Q in existence of one fin leads to augmentation of PEC about 51.38%. [ABSTRACT FROM AUTHOR]

This study presents a solar-powered parabolic dish desalination system with a solar tracking system and conical receiver. It efficiently transforms solar radiation into heat and evaporates saltwater, producing fresh water. The system is sustainable and affordable, making it a viable solution for water desalination in areas with limited access to fresh water. It achieves a high conversion rate from saltwater to fresh water, while consuming minimal energy. The results indicate that the system effectively utilizes solar energy, exhibiting high efficiency levels ranging from 78.56% to 82.77%, with an average efficiency of 80.79%. This system offers an effective solution to meet the growing demand for fresh water in water-scarce regions.

Daylighting plays an important role in decreasing power usage in office buildings and enhancing indoor environments. Reducing the use of energy and producing energy from renewable sources will result in lower greenhouse gas emissions. Daylighting is a method of providing light indoors through the use of windows, solar panels, optical fibers, parabolic mirrors and other forms of daylight technologies. The proposed fiber optic daylighting system will illuminate the light uniformly in interior space. Parabolic mirror and Frensnel lens are two different efficient approaches available for fiber-based day lighting system. Captured light is passed via concentrator, fiber and lenses. Uniform lighting at the capture point eliminates the heat problem when incorporating optical plastic fiber is critical in making the device cost-effective. Collimated light increases device performance helping to inject full light into the optical fibres. From simulation setup will verify that uniform intensity of light will be illuminated to different regions of buildings by the fiber optic bundle. Collimated lighting and reduction of shadows caused by mechanical parts and the convex reflector will enhances the system's efficiency. Uniform illumination will be given at all time by using hybrid system. Using solar day lighting in homes and offices via optical fibre cables is a potential way to reduce the energy used for artificial lighting while also improving visual comfort and human health. Analysis and discussion have been conducted on the impact of optical fibre diameter on the brightness and homogeneity of light. This efficient technology can lower energy costs and also helps in climate change challenges. [ABSTRACT FROM AUTHOR]

Presented in this paper is a conceptual design by computer simulation of a monopulse reflector antenna with dual-circularly polarized sum patterns and linearly polarized azimuth and elevation difference patterns, which can be called a semi-dual polarized antenna. The proposed antenna consists of a five-element monopulse feed and a prime-focus parabolic reflector. The novelty of the proposed antenna is a monopulse feed consisting of a dual-circularly polarized square waveguide sum channel radiator and linearly polarized rectangular waveguide azimuth and elevation difference channel radiators. The separation of dual circular polarization is realized by a septum polarizer. The difference pattern is obtained by feeding two rectangular waveguides in opposite directions using a coaxial probe. The proposed monopulse feed geometry requires only two power combiners for a monopulse comparator network while providing dual-polarized performance comparable to the full dual-polarized sum and difference channel monopulse scheme. The concept of the proposed antenna is shown in a conceptual design by computer simulation. The monopulse feed is designed first, and then combined with a parabolic reflector. The designed monopulse reflector antenna operates at 14.5–16.0 GHz, and shows excellent sum and difference pattern characteristics: 36.1–36.7 dBc sum channel directivity with 0.65 dB boresight axial ratio and 32.6–32.9 dBi difference channel directivity with 1.56–1.66° crossover angle. [ABSTRACT FROM AUTHOR]

The gain and front to back ratio of UWB bowtie antenna is improved in this paper to meet the requirements of Ground Penetrating Radar (GPR) applications. GPR antennas must have good gain toward the ground to achieve more ability of penetration, and high front to back (F/B) ratio to save the power and reduce external electromagnetic interferences. This is done by adding planar and parabolic reflectors to the proposed antenna, which has fractional bandwidth (FBW) of 138% within (1-5.45) GHz. The simulation has been carried out using CST Microwave Studio to study the effect of each reflector on the gain and F/B ratio. Toward the ground, planar reflector achieves maximum gain improvement of 4.75 dB, and maximum F/B ratio of 14 dB with bandwidth (1-2) GHz only. So, it cannot change the general behavior of main antenna gain. While parabolic reflector achieves maximum gain improvement of 35.35 dB, maximum F/B ratio of 33.79 dB over the whole bandwidth, and FBW of 156% within bandwidth (0.92-7.44) GHz. According to these results antenna with parabolic reflector is fabricated, and the gain and return loss is measured. The measurements show a good agreement with the simulation results.

An intelligent security model for the big data environment is presented in this paper. The proposed security framework is data sensitive in nature and the level of security offered is defined on the basis of the data secrecy standard. The application area preferred in this work is the healthcare sector where the amount of data generated through the digitization and aggregation of medical equipment’s readings and reports is huge. The handling and processing of this great amount of data has posed a serious challenge to the researchers. The analytical outcomes of the study of this data are further used for the advancement of the medical prognostics and diagnostics. Security and privacy of this data is also a very important aspect in healthcare sector and has been incorporated in the healthcare act of many countries. However, the security level implemented conventionally is of same level to the complete data which not a smart strategy considering the varying level of sensitivity of data. It is inefficient for the data of high sensitivity and redundant for the data of low sensitivity. An intelligent data sensitive security framework is therefore proposed in this paper which provides the security level best suited for the data of given sensitivity. Fuzzy logic decision making technique is used in this work to determine the security level for a respective sensitivity level. Various patient attributes are used to take the intelligent decision about the security level through fuzzy inference system. The effectiveness and the efficacy of the proposed work is verified through the experimental study.

This paper presents the design of a parabolic reflector fed through a patch antenna array feed to enhance its directivity and radiation properties. Adaptive beam formers steer and alter an array's beam pattern to increase signal reception and minimize interference. Weight selection is a critical difficulty in achieving low SLL and beam width. Low Side Lobe Level [SLL]and narrow beam reduce antenna radiation and reception. Adjusting the weights reduces SLL and tilts the nulls. Adaptive beam formers are successful signal processors if their array output converges to the required signal. Smart antenna weights can be determined using any window function. Half Power Beam Width and SLL could be used to explore different algorithms. Both must be low for excellent smart antenna performance. In noisy settings, ACLMS and CLMS create narrow beams and side lobes. AANGD offers more control than CLMS and ACLMS. The blend of CLMS and ACLMS is more effective at signal convergence than CLMS and AANGD. It presents an alternative to the conventionally used horn-based feed network for C-band applications such as satellite communication. Broadside radiation patterns and 4x4 circular patch antenna arrays are used in the proposed design. 1400 aperture illumination is provided by the array's feed parabolic reflector, whose F/D ratio is 0.36. The proposed design's efficacy is assessed using simulation analysis. [ABSTRACT FROM AUTHOR]

Parabolic reflectors have very good directivity. However, when put behind a partially reflecting surface, they suffer from destructing in‐phase rays and they experience deteriorated characteristics. In this work we consider fixing this impediment and we enhance the low profile by providing a new approach based on ray optics model. This approach grabs the equations of multiple reflections between the two components to re‐construct a collimated beam in the normal direction of the radiated element. This model is confirmed with a peak simulated directivity of about 28 dB of the new compact parabolic quasi Fabry–Pérot cavity. The highly directive and low profile proposed model is valid for both microwave and mmWave bands (from 5 to 60 GHz). The measured realized gain of the fabricated prototype is compared with a simulated data resulting in a peak of about 25.2 dB. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new kind of nanoantenna for effective illumination of parabolic surfaces, constituting of a silicon cylinder acting as a reflector and dipole source as an emitter. Tailored parameters of the nanoantenna ensure specific radiation pattern with broad main lobe and strongly suppressed side lobes that in the E-plane of the dipole is quite similar to the ideal “П” configuration, necessary for an as uniform as possible illumination of parabolic surfaces. This above radiation pattern is mostly due to the properly designed dielectric inclusion in the reflector that, therefore, is free of any losses. Consequently, we study how varying the antenna parameters affects the radiation pattern.Results of our numerical simulations are compared with already existing ones and highlight the principal features that provide the desired effect. Furthermore, due to the simple geometry of the inclusions, the considered nanoantenna, required in application such as nanoreflector antennas and/or nanophotonic devices, exhibits advantages in manufacturing processes with respect to already proposed solutions.

An intelligent security model for the big data environment is presented in this paper. The proposed security framework is data sensitive in nature and the level of security offered is defined on the basis of the data secrecy standard. The application area preferred in this work is the healthcare sector where the amount of data generated through the digitization and aggregation of medical equipment's readings and reports is huge. The handling and processing of this great amount of data has posed a serious challenge to the researchers. The analytical outcomes of the study of this data are further used for the advancement of the medical prognostics and diagnostics. Security and privacy of this data is also a very important aspect in healthcare sector and has been incorporated in the healthcare act of many countries. However, the security level implemented conventionally is of same level to the complete data which not a smart strategy considering the varying level of sensitivity of data. It is inefficient for the data of high sensitivity and redundant for the data of low sensitivity. An intelligent data sensitive security framework is therefore proposed in this paper which provides the security level best suited for the data of given sensitivity. Fuzzy logic decision making technique is used in this work to determine the security level for a respective sensitivity level. Various patient attributes are used to take the intelligent decision about the security level through fuzzy inference system. The effectiveness and the efficacy of the proposed work is verified through the experimental study. [ABSTRACT FROM AUTHOR]

Presented in this paper is a conceptual design by computer simulation of a monopulse reflector antenna with dual-circularly polarized sum patterns and linearly polarized azimuth and elevation difference patterns, which can be called a semi-dual polarized antenna. The proposed antenna consists of a five-element monopulse feed and a prime-focus parabolic reflector. The novelty of the proposed antenna is a monopulse feed consisting of a dual-circularly polarized square waveguide sum channel radiator and linearly polarized rectangular waveguide azimuth and elevation difference channel radiators. The separation of dual circular polarization is realized by a septum polarizer. The difference pattern is obtained by feeding two rectangular waveguides in opposite directions using a coaxial probe. The proposed monopulse feed geometry requires only two power combiners for a monopulse comparator network while providing dual-polarized performance comparable to the full dual-polarized sum and difference channel monopulse scheme. The concept of the proposed antenna is shown in a conceptual design by computer simulation. The monopulse feed is designed first, and then combined with a parabolic reflector. The designed monopulse reflector antenna operates at 14.5–16.0 GHz, and shows excellent sum and difference pattern characteristics: 36.1–36.7 dBc sum channel directivity with 0.65 dB boresight axial ratio and 32.6–32.9 dBi difference channel directivity with 1.56–1.66° crossover angle.

In the present study, performance of the fabricated evacuated U-tube solar collector integrated parabolic reflector (EUSCIPR) and conventional evacuated U-tube solar collector (CEUSC) are analysed experimentally. With reference to humid climatic conditions, a 3D model is developed for comparing the thermal performance of EUSCIPR with a CEUSC. Developed model is validated with field test data and found in good agreement among them. Heat transfer fluid (HTF) temperature difference, energy intake/heat gain and thermal efficiency of the solar collectors are investigated experimentally at various ambient temperatures and solar intensities. From the experimental investigations, it was observed that, in a sunny day, the energy losses incurred across the solar collectors was high during peak hour (1: 20 PM). From the numerical studies, it is found that within the given operating range, the thermal efficiency of the EUSCIPR is 14.1% higher than CEUSC. Further, for a given inlet condition, the contour plots for variation of HTF temperature along the U-tube of EUSCIPR and CEUSC are predicted numerically, and the obtained results are discussed in detail. [ABSTRACT FROM AUTHOR]

[Display omitted] • The paper introduces a new passive collector design for the purpose of light collection for daylighting. • Maintain uniform lighting levels for the most part of the day under clear sky sun. • The average illuminance of around 400 lx was observed on the floor of the experimental room for the most part of the day. • The performance of proposed designed collectors leads under the low-altitude sun when compared to conventional designs. A tubular skylight (TS) is an effective system for transporting natural sunlight into the building interiors. However, the passive nature of the system may not account for the changing orientation of the sun and the conventional daylight collector designs like transparent dome are less effective under low altitude sun. This paper focuses on the performance evaluation of specifically designed TS having rectilinear parabolic-profile reflectors integrated with plane surface reflectors and wedge-shaped prism for daylight collection. The designed configuration redirects the low altitude incident rays efficiently into a vertical mirror light pipe having a rectangular cross-section and aims at giving desired levels of lighting throughout the sunny day. Numerical analysis of the same was carried out for various sky conditions. Experimental results for the proposed TS design show improved lighting levels during the low-altitude sun and reduced but consistent lighting during the mid-day. Average illuminance of ~ 400 lx was observed on the floor of the experiment room for the most part of the day. Along with capturing beam sunlight a significant amount of diffuse daylight capturing ability under clear sky conditions is observed using the proposed TS. The average illuminance value obtained on the work plane during winter solstice through the most optimized configured TS was more than twice the lighting value achieved by a conventional daylight-collecting transparent dome and almost twice the lighting value achieved by a TS with a prismatic dome collector. Under overcast sky conditions, the performance of the proposed configuration of TS is at par. [ABSTRACT FROM AUTHOR]

In this article, a multi‐beam substrate integrated waveguide (SIW) leaky‐wave antenna (LWA) is proposed for millimeter‐wave radar applications, which owns the advantages of 2‐D scanning capability, high gain, low profile, and single layer configuration. The proposed antenna consists of a beam‐forming network (BFN) based on a 2‐D SIW parabolic reflector with eight waveguide feedings, and a 16‐element LWA array. The open‐stopband of the LWA is suppressed by employing a longitudinal slot into a conventional transverse slot LWA unit. In the E‐plane, the BFN can generate eight desired distributions of the amplitude and the phase gradients which steers beam from −17.3° to 30.8° with the crossover level higher than −5.22 dB. In the H‐plane, the frequency scanning LWA array can offer a continuous beam scanning range from −23° to 19° with operating frequency from 21 to 29 GHz. Finally, the antenna is prototyped and experimentally verified. The measured results are in accord with the simulated ones. The characteristics of the proposed antenna make it a very promising solution for applications in low‐cost millimeter‐wave radar systems. [ABSTRACT FROM AUTHOR]

A K‐band (18–27 GHz) dielectric‐loaded waveguide antenna is designed as the feed for a parabolic reflector. The antenna is composed of a waveguide launcher and a dielectric load. The waveguide launcher is fabricated by selective laser melting using aluminium alloy. The dielectric load is fabricated by stereolithography using resin. The aperture field distribution of the antenna is tuned by extending the E‐ and H‐walls of the waveguide launcher to radiate a sidelobe‐reduced main beam in the boresight from −90° to + 90°. The agreement is achieved between the simulation and measurement. It has impedance bandwidth of |S11|<−10 from 18 to 27 GHz, the maximum gain of 11.8 dBi @ 19 GHz, and 3‐dB gain bandwidth from 18 to 25 GHz. For the sidelobe reduced, simple design and low cost, the proposed antenna features a good candidate as the feed for a parabolic reflector. [ABSTRACT FROM AUTHOR]

A millimeter-wave substrate-integrated waveguide (SIW) antenna with the ability of generating 2-D steerable large depth-of-field beam is presented in this article. First, a transverse antenna topology feeding with the series- and the parallel-network is employed to generate the limited-diffractive beam with large depth of field to overcome the problem that the conventional radial generator cannot steer its beam electronically. The proposed antenna is achieved by combining a modulated leaky-wave slot array antenna with a modified multibeam SIW parabolic reflector. The modulated leaky-wave slot array with stepped-width is designed to able to steer the limited-diffractive beam in the horizontal dimension with the frequency, which validates the frequency scanning feasibility of the limited-diffractive beam. Then a modified SIW parabolic reflector with matching loads is used to feed the modulated leaky-wave SIW slot array antenna to generate multiple limited-diffractive beams in the vertical dimension. A large depth of field of about $43\lambda _{0}$ is achieved of the central limited-diffractive beam. The measurements are in good agreement with the simulated results. [ABSTRACT FROM AUTHOR]

This paper presents a unified speech enhancement system to remove both background noise and interfering speech in serious noise environments by jointly utilizing the parabolic reflector model and neural beamformer. First, the amplification property of paraboloid is discussed, which significantly improves the Signal-to-Noise Ratio (SNR) of a desired signal. Therefore, an appropriate paraboloid channel is analyzed and designed through the boundary element method. On the other hand, a time-frequency masking approach and a mask-based beamforming approach are discussed and incorporated in an enhancement system. It is worth noticing that signals provided by the paraboloid and the beamformer are exactly complementary. Finally, these signals are employed in a learning-based fusion framework to further improve the system performance in low SNR environments. Experiments demonstrate that our system is effective and robust in five different noisy conditions (speech interfered with factory, pink, destroyer engine, volvo, and babble noise), as well as in different noise levels. Compared with the original noisy speech, significant average objective metrics improvements are about Δ STOI = 0.28, Δ PESQ = 1.31, Δ fwSegSNR = 11.9. [ABSTRACT FROM AUTHOR]

Antennas which are one of the most important components that designate the system characteristic in radar systems, nowadays have a substantial position in military as well as civil areas. Due to their narrow beamwidth and high gain radiation reflector antennas are frequently preferred in radar systems. High gain and low sidelobe/backlobe levels are one of the most significant parameters in reflector antenna design. Sidelobes in radiation patterns cause the energy to radiate in undesirable directions. In this study, parabolic reflector antenna design with low near sidelobe and backlobe levels on horizontal/vertical planes and its performance analysis are presented. For this purpose, three element Yagi array fed parabolic reflector antenna with suppressed near sidelobes and backlobes by novel shroud and strips is designed. Thus, for the proposed reflector antenna; a gain of 24,5 dB, sidelobe level of -26 dB and 28,8 dB respectively on horizontal and vertical plane, backlobe level of -42,3 dB and half power beamwidth of 10° on 1100-1200 MHz frequency band are achieved. It is shown that our design fulfills the ETSI Class-2 standards. Design, analysis and optimization studies are performed on CST program.

After the development of portable glucose biosensor, challenges have remained to fabricate more portable devices for sensitive and reproducible detection of other biomarkers. Here, we fabricated a hand-held device for the quantification of carcinoembryonic antigen (CEA) or any other biomarkers based on electrochemiluminescence (ECL) using a bipolar electrode (BPE). The detection mechanism was based on a sandwich assay composed of a capture antibody and a secondary antibody conjugated with a robust ECL reporter. The ECL reporter was fabricated by conjugation of luminol on streptavidin-coated gold nanoparticle (Lum@SA-AuNP), leaving the biotin binding sites of the streptavidin intact for further conjugation with secondary antibody. This novel controlled functionalization strategy significantly enhanced the reproducibility and robustness of the biosensor. Moreover, an inventive parabolic reflector was implemented in the design, in order to maximize the lights to be captured by the photodiode (detector) and measured by a simple multimeter. Due to the synergetic signal amplification, the developed biosensor demonstrated a low sensitivity of 2.51 ng/ml with a linear detection range from 5 to 300 ng/ml with the ability to perform well in spiked-in samples. The designed sensing mechanism can definitely pave the way for further development of miniaturized devices in multiple formats., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Abstract We have developed a new threshold Cherenkov detector for online triggering in the H-dibaryon search experiment at the K1.8 beam line at J-PARC. Silica aerogel radiators with a refractive index of n = 1. 04 will cover an effective area of 550 × 220 mm 2. The Cherenkov detector will be placed in a high magnetic field between two spectrometer magnets. Three prototypes and a real-size mockup module have been tested using pions and protons from photoproduction at SPring-8. For momentum ranging from 1.0 to 1.1 GeV ∕ c , a suppression factor of 1 0 3 could be achieved for pions, with a factor of 1 0 − 2 for proton misidentification. [ABSTRACT FROM AUTHOR]

Abstract A cylindrical parabolic reflector, composed of mesh grid, is modeled by a resistive surface. The analysis of the scattered waves is performed by the physical optics integral, which was developed for resistive surfaces. The integral is evaluated asymptotically for large values of the wave-number in high-frequencies. The geometrical optics and diffracted fields are obtained by the methods of stationary phase and edge point respectively. The uniform forms of the diffracted waves are derived. The total wave and its components are investigated numerically for different values of surface resistivity. [ABSTRACT FROM AUTHOR]

This paper proposes a compact continuous transverse stub (CTS) array that utilizes substrate integrated waveguide (SIW) technology. The CTS array includes six radiation slots and is powered by a novel linear source generator (LSG) with a parabolic reflector located on the bottom layer. The LSG converts the input wave into a planar wave that is subsequently coupled to the parallel-plate waveguide (PPW) of the CTS array through a coupling slot. By utilizing different input ports, the CTS array can produce planar waves in various directions, allowing for the production of beams with different pointing. The CTS array comprises four-layer substrates with a total thickness of only 0.24 λ 0. The measurement results show that the reflection coefficient of the array is below -10.9 dB in the operating range of 33-37 GHz. The array scanning angle theta can be up to about ±38°at the center frequency of 35 GHz, with a maximum gain of 20.9 dBi. When using the middle port feed, the measurement gain is superior to 20.1dBi and the radiation efficiency is above 87.1% in the 33-37 GHz range. Simulation and measurement results are in agreement, demonstrating that the proposed CTS array is suitable for multibeam applications in the K a -band. [ABSTRACT FROM AUTHOR]

Ocean wave energy is a rapidly developing sector and has the potential to contribute a significant share to the global green energy transformation. However, nearshore coastal regions, in which energy harvesting devices are most commonly installed, experience low wave energy densities compared with offshore regions. This is a significant impediment to the commercialisation of the wave energy sector. This study proposes a low cost solution to these low wave energy density distributions at nearshore environments whilst simultaneously providing an effective coastal protection system. A parabolic energy concentrator wall is coupled with an oscillating water column wave energy converter. The parabolic concentrator reflects and consolidates the incident wave energy to a focal point, at which the wave energy convertor is positioned. Experimental investigations, supported by numerical modelling results confirm energy conversion performances significantly exceeding hitherto recorded wave energy converter efficiencies, with wave-to-wire conversion efficiency in the laboratory model exceeding 70%. Furthermore, the parabolic concentrator wall has an ancillary purpose to act as a shoreline protection barrier. The simplicity of design, high energy conversion efficiencies, and inherent shoreline defensive aspect of the proposed system deems it particularly suitable for deployment to remote island nations, or coastal communities vulnerable to coastal erosion that presently rely on fossil fuel consumption for energy generation. • A novel OWC WEC-parabola-breakwater system is developed. • The parabolic breakwater focusses the wave energy to the OWC WEC. • Physical experiments are supported by compressible numerical modelling. • The system achieves capture-width-ratios exceeding 2.0. • Wave-to-wire efficiencies of 0.7 are revealed. [ABSTRACT FROM AUTHOR]

Vision technologies are used in both industrial and smart city applications in order to provide advanced value products due to embedded self-monitoring and assessment services. In addition, for the full utilization of the obtained data, deep learning is now suggested for use. To this end, the current work presents the implementation of image recognition techniques alongside the original the quality assessment of a Parabolic Trough Collector (PTC) reflector surface to locate and identify surface irregularities by classifying images as either acceptable or non-acceptable. The method consists of a three-step solution that promotes an affordable implementation in a relatively small time period. More specifically, a 3D Computer Aided Design (CAD) of the PTC was used for the pre-training of neural networks, while an aluminum reflector surface was used to verify algorithm performance. The results are promising, as this method proved applicable in cases where the actual part was manufactured in small batches or under the concept of customized manufacturing. Consequently, the algorithm is capable of being trained with a limited number of data.

This paper presents a unified speech enhancement system to remove both background noise and interfering speech in serious noise environments by jointly utilizing the parabolic reflector model and neural beamformer. First, the amplification property of paraboloid is discussed, which significantly improves the Signal-to-Noise Ratio (SNR) of a desired signal. Therefore, an appropriate paraboloid channel is analyzed and designed through the boundary element method. On the other hand, a time-frequency masking approach and a mask-based beamforming approach are discussed and incorporated in an enhancement system. It is worth noticing that signals provided by the paraboloid and the beamformer are exactly complementary. Finally, these signals are employed in a learning-based fusion framework to further improve the system performance in low SNR environments. Experiments demonstrate that our system is effective and robust in five different noisy conditions (speech interfered with factory, pink, destroyer engine, volvo, and babble noise), as well as in different noise levels. Compared with the original noisy speech, significant average objective metrics improvements are about ΔSTOI = 0.28, ΔPESQ = 1.31, ΔfwSegSNR = 11.9.

In this paper at first, the ordinary septum polarizer has been designed and used for parabolic reflector feed in Ground station antenna. Next, a novel design of modified septum polarizer with wider beam-width is proposed for satellite antenna. Compactness, low weight, large bandwidth, high TX/RX isolation, low axial ratio as well as low loss are the advantages of the septum polarizer. The designed antenna has high purity circular polarization ( A R ≤ 1.6 d B $\left| {AR} \right| \le 1.6dB$ ) and low return loss. The frequency bandwidth of the antenna is about 27 % in the center frequency 11 GHz and the TX/RX isolation is better than 32 dB. Finally the septum polarizer, modified septum polarizer and reflector are fabricated and tested and there were good agreement between simulation and measurement results. [ABSTRACT FROM AUTHOR]

A stack of two identical flat circular membranes, bonded along the periphery can be inflated to form a reflector. To maintain the desired shape of the reflector surface, a supporting outer rim is required. An inflatable membrane reflector supported by an outer inflated toroidal rim structure is considered. Both the reflector and the toroidal rim are considered to be geometrically flat in the uninflated state. Initially, the circular membranes are pre-stretched and joined with the inner equator of the inflated torus, causing an inward radial force on the toroidal rim. The inflated shapes of the circular membranes (reflectors) under uniform pressure are obtained by an iterative solution scheme. The inflation problem is solved to determine the inflated shapes and the possible occurrence of wrinkling instability of the reflector or pull-in instability of the toroidal rim. The shape of the reflector is found to be close to a paraboloid whose focal length depends on the level of inflation and pre-stretch. Lower inflation pressure of the inflatable reflector is found to result in a better parabolic approximation of the reflecting surface. [ABSTRACT FROM AUTHOR]