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Tytuł:
Time-slot based architecture for power beam-assisted relay techniques in CR-WSNs with transceiver hardware inadequacies
Autorzy:
Umer, Mushtaq Muhammad
Jiang, Hong
Zhang, Qiuyun
Manlu, Liu
Muhammad, Owais
Powiązania:
https://bibliotekanauki.pl/articles/27311438.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
cognitive radio WSNs
energy harvesting
DF relaying
relay selection schemes in WSNs
hardware inadequacy in WSNs
wireless sensor networks
zbieranie energii
bezprzewodowa sieć czujników
WSN
sieci radia kognitywnego
przekaz DF
bezprzewodowe sieci sensoryczne
Opis:
Over the past two decades, numerous research projects have concentrated on cognitive radio wireless sensor networks (CR-WSNs) and their benefits. To tackle the problem of energy and spectrum shortfall in CR-WSNs, this research proposes an underpinning decode-&-forward (DF) relaying technique. Using the suggested time-slot architecture (TSA), this technique harvests energy from a multi-antenna power beam (PB) and delivers source information to the target utilizing energy-constrained secondary source and relay nodes. The study considers three proposed relay selection schemes: enhanced hybrid partial relay selection (E-HPRS), conventional opportunistic relay selection (C-ORS), and leading opportunistic relay selection (L-ORS). We present evidence for the sustainability of the suggested methods by examining the outage probability (OP) and throughput (TPT) under multiple primary users (PUs). These systems leverage time switching (TS) receiver design to increase end-to-end performance while taking into account the maximum interference constraint and transceiver hardware inadequacies. In order to assess the efficacy of the proposed methods, we derive the exact and asymptotic closed-form equations for OP and TPT & develop an understanding to learn how they affect the overall performance all across the Rayleigh fading channel. The results show that OP of the L-ORS protocol is 16% better than C-ORS and 75% better than E-HPRS in terms of transmitting SNR. The OP of L-ORS is 30% better than C-ORS and 55% better than E-HPRS in terms of hardware inadequacies at the destination. The L-ORS technique outperforms C-ORS and E-HPRS in terms of TPT by 4% and 11%, respectively.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 5; art. no. e146620
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Investigation of the MIMO Space Time Block Code Based Selective Decode and Forward Relaying Network over η–µ Fading Channel Conditions
Autorzy:
Shankar, Ravi
Raman, V. V. Raghava
Rane, Kantilal Pitamber
Sarojini, B. K.
Neware, Rahul
Powiązania:
https://bibliotekanauki.pl/articles/2058506.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
5G
MIMO
MRC
non-homogeneous fading channel
PEP
S-DF
SNR
Opis:
In this paper, we examine the end-to-end average pairwise error probability (PEP) and output probability (OP) performance of the maximum ratio combining (MRC) based selective decode and forward (S-DF) system over an η–µ scattering environment considering additive white Gaussian noise (AWGN). The probability distribution function (PDF) and cumulative distribution function (CDF) expressions have been derived for the received signal-to-noise (SNR) ratio and the moment generating function (MGF) technique is used to derive the novel closed-form (CF) average PEP and OP expressions. The analytical results have been further simplified and are presented in terms of the Lauricella function for coherent complex modulation schemes. The asymptotic PEP expressions are also derived in terms of the Lauricella function, and a convex optimization (CO) framework has been developed for obtaining optimal power allocation (OPA) factors. Through simulations, it is also proven that, depending on the number of multi-path clusters and the modulation scheme used, the optimized power allocation system was essentially independent of the power relation scattered waves from the source node (SN) to the destination node (DN). The graphs show that asymptotic and accurate formulations are closely matched for moderate and high SNR regimes. PEP performance significantly improves with an increase in the value of η for a fixed value of µ. The analytical and simulation curves are in close agreement for medium-to-high SNR values.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 1; 79--92
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Inclusive Performance Analysis of Single-branch Single-relay AF Transmission in a Mixed Rayleigh-Nakagami-m Fading Environment
Autorzy:
Benmahmoud, Slimane
Powiązania:
https://bibliotekanauki.pl/articles/307994.pdf
Data publikacji:
2019
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
amplify-and-forward (AF)
decode-and-forward (DF)
two/dual-hop relaying
outage probability
ergodic capacity
signal-to-noise ratio (SNR)
Opis:
In this paper, the end-to-end performance of a single-branch two-hop amplify-and-forward (AF) relaying network in a mixed Rayleigh-Nakagami-m fading environment, is investigated. Four different fading scenarios and three standard relay configurations for each scenario are considered. Exact analytical expressions for the outage probability and tight upper bounds for the ergodic capacity are derived. Results of Monte Carlo simulations are provided to verify the accuracy of the analytical results.
Źródło:
Journal of Telecommunications and Information Technology; 2019, 3; 39-48
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nanostructure features, phase relationships and thermoelectric properties of melt-spun and spark-plasma-sintered skutterudites
Autorzy:
Kogut, Iu.
Nichkalo, S.
Ohorodniichuk, V.
Dauscher, A.
Candolfi, C.
Masschelein, P.
Jacquot, A.
Lenoir, B.
Powiązania:
https://bibliotekanauki.pl/articles/1052685.pdf
Data publikacji:
2018-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Eb
72.15.Jf
72.20.Pa
66.70.Df
81.20.Ev
81.16.-c
81.40.Gh
Opis:
Reduction of thermal conductivity remains a main approach relevant to enhancement of figure-of-merit of most thermoelectric materials. Melt spinning combined with spark plasma sintering appears to be a vital route towards fine-grain skutterudites with improved thermoelectric performance. However, upon high-temperature processing the Fe_{4-x}Co_{x}Sb_{12}-based skutterudites are prone to decompose into multiple phases, which deteriorate their thermoelectric performance. In this study we addressed the effects of combined melt spinning and spark plasma sintering on the phase composition and microstructural properties of filled Fe_{4-x}Co_{x}Sb_{12} as well as their influence on thermoelectric characteristics of these compounds. The crystallites of filled Fe_{4-x}Co_{x}Sb_{12} were effectively reduced to sizes below 100 nm upon melt spinning, but also severe decomposition with weakly preserved nominal phase was observed. Spark plasma sintering of melt spun skutterudites resulted in even further reduction of crystallites. Upon short annealing and sintering the n-type materials easily restored into single-phase filled CoSb₃ with nanoscale features preserved, while secondary phases of FeSb₂ and Sb remained in p-type compounds. Relatively high figure-of-merit ZT_{max} of 0.9 at T ≈ 400°C has been gained in nanostructured Yb_{x}Co₄Sb_{12}, however, no significant reduction of thermal conductivity was observed. Abundant impurities in p-type filled Fe_{4-x}Co_{x}Sb_{12} led to drastic drop in their ZT, which even further degraded upon thermal cycling.
Źródło:
Acta Physica Polonica A; 2018, 133, 4; 879-883
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of second harmonic generation in KDP/Al₂O₃ crystalline nanocomposite
Autorzy:
Andrushchak, N.
Kulyk, B.
Göring, P.
Andrushchak, A.
Sahraoui, B.
Powiązania:
https://bibliotekanauki.pl/articles/1052895.pdf
Data publikacji:
2018-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.07.Bc
61.46.Df
68.37.Ps
42.65.Ky
Opis:
Crystalline nanocomposite KDP/Al₂O₃ was obtained by growth of KDP nanocrystals inside nanopores of amorphous alumina matrix (Al₂O₃) with pores diameter of 35 nm. Performed atomic force microscopy and X-ray diffraction analysis confirmed that Al₂O₃ matrix is filled up with a tetragonal phase KDP nanocrystals in preferred crystallographic orientation [100]. The nonlinear optical response was studied by means of second harmonic generation via the Maker fringe technique employing picosecond laser pulses at wavelength of 1064 nm. The polarization dependent second harmonic generation response was observed mainly due to the macroscopic crystalline structure anisotropy of KDP/Al₂O₃ nanocomposite. The investigation of such type of nanocomposites which combine nanoscale nonlinear optical materials has a great importance since they may improve the performance of entire system.
Źródło:
Acta Physica Polonica A; 2018, 133, 4; 856-859
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Satellites Orientation Method using a Torque Magnetic Drive
Autorzy:
Korobiichuk, I.
Kachniarz, M.
Nowicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/1030758.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.55.Ge
04.30.Tv
07.05.Rm
07.07.Df
Opis:
Small values of external perturbation forces made it possible to use a torque magnetic drive as a control system. Today, satellite orientation systems use pulsed-type algorithm for discharge of an angular momentum accumulator. The feasibility of using other algorithms (continuous, continuous-pulsed and algorithm of torque magnetic drive operation using `forecast' models of accumulated angular momentum and geomagnetic field) is not covered and not examined, although each has certain advantages for certain types of satellites and their conditions of operation in space. The article highlights satellites operating conditions in space, considers satellites orientation method using a torque magnetic drive and substantiates the necessity of satellite motion simulation with further establishing a technique for evaluation of orientation system given the effect of permanent magnetic and gravitational fields, the type of discharge of accumulated angular momentum, the height of trajectory and the nature of random perturbations.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 722-724
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermoelectric properties of Ca₂Sn/Ca₃SnO
Autorzy:
Kalinowski, L.
Fijałkowski, M.
Goraus, J.
Powiązania:
https://bibliotekanauki.pl/articles/1047668.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Jf
66.70.Df
Opis:
We measured thermopower, thermal conductivity and electrical resitivity for Ca₂Sn sample across 4-350 K temperature range. Contrary to expectations from recent DFT based calculations the thermopower is not particularly large, reaching 7 μV at 350 K. The thermoelectric figure of merit renders this material in unmodified form practically unusable for thermoelectric aplications.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 384-386
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Water-Sorption Effects near Grain Boundaries in Modified MgO-Al₂O₃ Ceramics Tested with Positron-Positronium Trapping Algorithm
Autorzy:
Klym, H.
Ingram, A.
Shpotyuk, O.
Hadzaman, I.
Chalyy, D.
Powiązania:
https://bibliotekanauki.pl/articles/1030933.pdf
Data publikacji:
2018-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Je
07.07.Df
Opis:
Water-sorption processes near grain boundaries in the MgO-Al₂O₃ ceramics prepared at different temperatures were studied using positron annihilation lifetime spectroscopy. Numerical values of three- and four-component treatment of spectra were used for study of physical- and chemical-sorption processes in the MgO-Al₂O₃ ceramics. To apply mathematical approach in the form of positron-positronium trapping algorithm into three-component treatment of positron annihilation lifetime spectra it was shown that physical-adsorbed water did not modify positron trapping sites near grain boundaries in water-immersed MgO-Al₂O₃ ceramics and localized mainly in nanopores. The chemically-adsorbed water modifies structural extended defects located near grain boundaries that accompanied them by void fragmentation at water desorption.
Źródło:
Acta Physica Polonica A; 2018, 133, 4; 864-868
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of Pressure Sensor Based on Two-Dimensional Photonic Crystal
Autorzy:
Zouache, T.
Hocini, A.
Harhouz, A.
Mokhtari, R.
Powiązania:
https://bibliotekanauki.pl/articles/1033334.pdf
Data publikacji:
2017-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.70.Qs
78.67.Pt
07.07.Df
42.79.-e
Opis:
In this work, we design a new pressure sensor based on two-dimensional photonic crystal waveguide coupled to a point-defect resonant microcavity. The mechanism of sensing is based on the change of the germanium refractive index as function of the hydrostatic pressure P. The resonant wavelength will shift when pressure variation induces change in the refractive indexes of the structure. The pressure variation causes the shifting of defect modes. The properties of the refractive index sensor are simulated using the finite-difference time-domain algorithm and the plane wave expansion method. These kinds of sensors have many advantages in compactness, high sensitivity, and various choices of materials.
Źródło:
Acta Physica Polonica A; 2017, 131, 1; 68-70
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic and Mössbauer Study of Cerium-Based Reactive Sorbent
Autorzy:
Jiraskova, Y.
Bursik, J.
Zivotsky, O.
Lunacek, J.
Janos, P.
Powiązania:
https://bibliotekanauki.pl/articles/1032876.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Tt
75.60.Ej
76.80.+y
61.46.Df
75.30.Kz
75.50.Bb
Opis:
A new kind of magnetically separable composite consisting initially of magnetite and cerium carbonate nanograins was investigated using magnetic and Mössbauer methods at room and low temperatures. Various stages of calcination treatment in air resulted in a transformation of the cerium carbonate into cerium dioxide and magnetite into more complicated iron oxide compositions. The final CeO₂ nanograins on the surface of α-Fe₂O₃ were obtained after calcination at 973 K.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 1096-1098
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure and Magnetic Properties of Iron/Iron-Oxide Nanoparticles Prepared by Precipitation from Solid State Solution
Autorzy:
Milkovič, O.
Gamcová, J.
Sopko, M.
Škorvánek, I.
Powiązania:
https://bibliotekanauki.pl/articles/1030258.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.46.Df
Opis:
The influence of precipitation temperature on structural and magnetic properties of iron/iron-oxide nanoparticles is investigated. Nanoparticles were prepared by precipitation of γ-Fe precipitates in Cu-Fe solid solution and subsequently isolated by matrix dissolution. Precipitation annealing temperatures were 773, 873, and 973 K. Nanoparticles core-shell structure and morphology were characterized by X-ray diffraction, high-resolution transmission electron microscopy, and selected area electron diffraction. These measurements showed that average diameter of nanoparticles increases with precipitation temperature from 8.5 nm to 20.5 nm. The measurements of magnetization as a function of temperature and applied field have been performed by SQUID magnetometer in temperature range from 5 K to 200 K.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 747-749
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of sonication and silver nanoparticles doped on viscoelastic structure of agarose gel
Autorzy:
Żyła, G.
Stompor, M.
Kopańska, M.
Stagraczyński, R.
Fal, J.
Traciak, J.
Trybus, M.
Wolski, S.
Zawlik, I.
Cebulski, J.
Konefał-Janocha, M.
Cholewa, M.
Powiązania:
https://bibliotekanauki.pl/articles/1055020.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
83.10.Tv
83.60.Df
83.80.Hj
62.20.F-
66.20.Ej
Opis:
The paper presents result of experimental measurements of viscoelastic properties of agarose gel after sonication and with silver nanoparticles doped. Researches were conducted using a HAAKE MARS 2 rheometer (Thermo Electron Corporation, Karlsruhe, Germany), with serrated plate-plate measuring geometry. Viscoelastic properties of samples were measured with oscillation tests at constant deformation rate 0.1%, and frequency 1 Hz in the temperature range from 278 to 348 K. It was presented that using the sonication before solidification of gel results in increases of the storage modulus and complex viscosity of the solidified gel. It was also presented that when silver nanoparticles are doped into agarose gel, storage modulus and complex viscosity start to decrease at lower temperature.
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 152-154
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Penetration of Gold Nanoparticles into Silicon Dioxide
Autorzy:
Ilkiv, I.
Kotlyar, K.
Amel'chuk, D.
Lebedev, S.
Cirlin, G.
Bouravleuv, A.
Powiązania:
https://bibliotekanauki.pl/articles/1033145.pdf
Data publikacji:
2017-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
62.23.Pq
61.46.Df
68.08.Bc
Opis:
We report on an experimental study of the thermal annealing processes under air and nitrogen atmospheres of colloidal Au nanoparticles deposited onto SiO₂/Si(100) samples. It was shown that Au nanoparticles during annealing under ambient conditions could penetrate inside silicon dioxide layers forming pores at that their lengths were found to be dependent on the annealing time. The influence of oxygen on the penetration process is discussed. At the same time, the annealing of Au nanoparticles under nitrogen conditions did not result in the formation of pores.
Źródło:
Acta Physica Polonica A; 2017, 132, 2; 366-369
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trend Detection in Climate Change Indicators Using Non-Parametric Statistics: A Case Study of Abu Dhabi, United Arab Emirates
Autorzy:
Basarir, A.
Arman, H.
Hussein, S.
Murad, A.
Aldahan, A.
Abdulla Al-Abri, M.
Powiązania:
https://bibliotekanauki.pl/articles/1031779.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
92.70.Kb
92.05.Df
Opis:
This study focuses on detecting trends for climate change indicators, such as average monthly temperature, rainfall, humidity, and wind speed for fourteen stations located between Al Ain and Abu Dhabi cities of the United Arab Emirates. Mann-Kendall non-parametric test was run on monthly time series data for the period 2003-2015 with consideration of seasonality. Significant increasing/decreasing trends in rainfall (for four stations), humidity (for six stations), and wind speed (for nine stations) were detected while no significant trend was observed in temperature for all stations.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 655-657
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructure characterization of noble metal-silica nanocomposites
Autorzy:
Zienkiewicz-Strzałka, M.
Pikus, S.
Powiązania:
https://bibliotekanauki.pl/articles/1075855.pdf
Data publikacji:
2016-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.46.Df
Opis:
The presence of highly dispersed metal particles on solid supports with well-defined microstructure is important in the field of functional materials, active catalysts as well as bionanomaterials for medical applications. Noble metal nanostructures, in particular silver, palladium, and platinum nanoparticles were formed from ammine complexes ([Pt(NH₃)₄]Cl₂, [Ag(NH₃)₂]OH, and [Pd(NH₃)₄]Cl₂) and supported on high ordered mesoporous silica (SBA-15) and aluminosilica matrix. In this work, the distribution, composition and crystal structure of supported noble metal nanoparticles were determined and characterized. Finally the stability of incorporated nanostructures was confirmed. The microstructures of the obtained samples were analyzed by high resolution transmission electron microscopy. Obtained results indicated that developed procedures of synthesis and modification of mesoporous ordered silica or their derivate by proposed nanostructures are effective and allow to obtain new nanocomposites and nanocatalysts in repeatable and controlled way.
Źródło:
Acta Physica Polonica A; 2016, 130, 4; 972-974
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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