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1

Hybrid adaptive beamforming approach for antenna array fed parabolic reflector for C-band applications

Bawane Sheetal, Kumar Panda Debendra

Journal of Automation Mobile Robotics and Intelligent Systems

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2023

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Vol. 17, No. 1

45--50

EN

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 for‐ mers steer and alter an array’s beam pattern to increase signal reception and minimize interference. Weight selec‐ tion 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 con‐ verges 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 pro‐ vided by the array’s feed parabolic reflector, whose F/D ratio is 0.36. The proposed design’s efficacy is assessed using simulation analysis.

2

Fuzzy Logic Based Intelligent Data Sensitive Security Model for Big Data in Healthcare

Dubey Somya, Verma Dhanraj

International Journal of Electronics and Telecommunications

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2022

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Vol. 68, No. 2

245--250

EN

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.

3

Konwersja energii promieniowania słonecznego z wykorzystaniem zwierciadeł parabolicznych

Fieducik J.

Inżynieria Ekologiczna

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2017

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Vol. 18, nr 4

47--53

PL

Wykorzystanie energii słonecznej jest obiecującym źródłem energii odnawialnej na pokrycie różnorodnych potrzeb energetycznych naszego społeczeństwa. Celem pracy będzie analiza możliwości konwersji energii słonecznej za pomocą zwierciadeł parabolicznych na energię cieplną niezbędną do zaspokojenia potrzeb w ciepłą wodę dla rodziny 4-osobowej. Niniejsze opracowanie przedstawia symulacje wykorzystania promieniowania słonecznego przy użyciu instalacji z koncentracją promieniowania. Paraboliczne zwierciadło kieruje skoncentrowaną wiązkę promieniowania słonecznego na rurę umieszczoną w ogniskowej zwierciadła, rura ta jest wypełniona wodą, która pod wpływem promieniowania słonecznego się ogrzewa. W artykule założono stałe wymiary zwierciadła i przekrój rury, natomiast symulację przeprowadzono dla różnych współczynników. Do obliczeń przyjęto, że współczynnik odbicia promieniowania słonecznego od zwierciadła r jest zmienny i przeprowadzono analizę jego wpływu na ilość ogrzanej cieczy. Współczynnik absorpcji promieniowania przez powierzchnię rury oznaczono przez a, współczynnik termicznej emisyjności powierzchni rury oznaczony e oraz przeprowadzono symulacje przy zmiennych jego wartościach na ilość ogrzanej cieczy. Z obliczeń i ich analizy wynika, że przy odpowiednio dobranych współczynnikach istnieje możliwość zaspokojenia potrzeb 4-osobowej rodziny w ciepłą wodę, przy użyciu zaproponowanej instalacji w warunkach Polski.

EN

The use of solar energy is a promising source of renewable energy to cover the energy needs of our society. The aim of the study will be to analyze the possibility of converting solar energy using parabolic reflectors to the heat energy needed to meet the needs for hot water of a family of 4-people. This study presents simulations of the use of solar radiation using radiant concentration systems. The parabolic mirror directs the concentrated beam of sunlight onto a tube located in the focal plane, which is filled with water that heats up under the influence of solar radiation. This article assumes constant mirror geometry and tube cross section, while the simulation is performed for different coefficients. For calculations it was assumed that the reflection coefficient of sunlight from the mirror r is variable and an analysis of its effect on the amount of heated liquid was made. The radiation absorption coefficient across the tube surface was determined by a, the thermal surface emissivity coefficient was determined as e and the simulations were performed at variable values for the amount of heated liquid. The calculations and their analysis show that it is possible to meet the needs for warm water of a 4-person family in Poland using appropriately chosen coefficients of the proposed installation.

4

Portable electro-optic device for performing serviceability check on IR guided missiles

Maini A. K., Agrawal V.

Opto-Electronics Review

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2009

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Vol. 17, No. 3

247-251

EN

Electro-optically guided weapons are the most potent and widely used munitions on land-based, aerial and ship-borne platforms because of their proven precision strike capability. Two such guided weapon categories include the IR guided surface-to-air and air-to-air missiles and laser guided bombs and missiles. The efficacy of the mission is critically dependent on the successful deployment of the weapon. This not only necessitates that periodic functionality check be carried out on these weapons, it should also be possible to perform functionality check also known as serviceability check even after they are strapped on to the launch platform. Serviceability check in the strap-on condition ensures a much higher hit probability. This paper presents the design and development of a portable electro-optic device that generates IR signatures in 3-5-µm band having the desired amplitude and spectral shape to match the IR signatures of target aircraft. A prototype was built using the proposed concept. The prototype was characterized in terms of its output amplitude and wavelength spectrum. The prototype was used to perform serviceability check on IR seekers of foreign origin. Test results are presented in the paper.