Nonlinear Transmission Research Articles

Shock Waves in Nonlinear Transmission Lines

In the first half of the article, interaction between the small amplitude travelling waves (“sound”) and the shock waves in the transmission line containing both nonlinear capacitors and nonlinear inductors is considered. Herein, the “sound” wave coefficient of reflection from (coefficient of transmission through) the shock wave is calculated. These coefficients are expressed in terms of the speeds of the “sound” waves relative to the shock and the wave impedances. In the second half of the article, the dissipation in the system is explicitly included into consideration, introducing Ohmic resistors shunting the inductors and also in series with the capacitors. This allows us to justify the conditions on the shocks, postulated in the first half of the article. This also allows us to describe the shocks as physical objects of finite width and study their profiles, same as the profiles of the waves closely connected with the shocks—the kinks. The profiles of the latter, and in some particular cases, the profiles of the former are obtained in terms of elementary functions.

Enhanced Hybrid Congestion Mitigation Strategy for ‘6LoWPAN-RPL based patient-centric IoHT’

The Internet of Healthcare Things (IoHT) is rapidly evolving, providing new opportunities to enhance healthcare delivery. However, the resource limitation of connected medical sensing devices leads to congestion, resulting in reduced network performance, delayed data transmission, and loss of critical medical information, which can have significant consequences in healthcare. To address this issue, this paper proposes an Enhanced Hybrid Congestion Mitigation Strategy (EHCMS) for IPv6 over low-power wireless personal area networks (6LoWPAN) and routing protocol for low-Power and lossy networks (RPL) based patient-centric IoHT (PC-IoHT). The EHCMS combines several techniques, including traffic management, network topology optimization, and load balancing, to enhance network performance and reduce congestion. The proposed framework is a hybrid strategy that utilizes resource- and traffic-control mechanisms to alleviate congestion in the 6LoWPAN-RPL-based patient-centric IoHT network. For the resource-control-based approach, a congestion-aware composite objective function is designed using a few congestion-specific routing metrics and formulated as a multi-attribute decision-making problem solved using Grey relational analysis (GRA). In addition, a non-linear multi-criteria optimization problem-based transmission rate adaptation mechanism is contrived as a traffic-control scheme for congestion mitigation. The effectiveness of the proposed EHCMS is evaluated using simulations on the Cooja simulator in the Contiki-3.0 OS and compared with existing congestion-alleviating strategies. The results demonstrate that the proposed framework can significantly reduce congestion in the IoHT network, perform better than existing works, and improve the quality of service. This research paper contributes to the field of IoHT by proposing an effective congestion mitigation strategy that enhances the reliability and performance of the PC-IoHT network, ultimately improving the quality of healthcare delivery.

Fast high voltage pulser for the southern advanced photon source

The Southern Advanced Photon Source (SAPS) is a planned fourth-generation synchrotron radiation facility featuring a low-emittance storage ring. For the H-7BA lattice design, the dynamic aperture is significantly smaller than the physical aperture, necessitating the use of a strip-line kicker based on an on-axis injection scheme. To minimize interference from the pulser on adjacent beams, a nanosecond pulser with stringent rise and fall time requirements is essential. A prototype pulser, based on a semiconductor opening switch, was developed to meet these demands. A nonlinear transmission line loaded with ferrite was utilized for pulse shaping, yielding favorable results. The prototype generated a pulse at a 50 Ω load with a rise time (10%–90%) of 2.4 ns, a fall time (90%–10%) of 3.9 ns, a pulse width (10%–10%) of 7.8 ns, and an amplitude of 19.8 kV. This paper presents the detailed design, optimization, and performance evaluation of the pulser.

Boosting photocatalytic efficiency and nonlinear optical response of graphitic carbon nitride by infusing carbon nanotubes

Nanostructured materials are widely studied for their light-driven physical and chemical processes, which are key to their potential in photophysical applications. We introduce a one-pot solid-state pyrolysis technique for the synthesis of graphitic carbon nitride/carbon nanotube (g-C3N4/CNT) composites. The formation of the composite was characterized through X-ray diffraction, scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy. Notably, UV-vis diffuse reflectance spectroscopy indicated a reduction in the bandgap of pure g-C3N4 from 2.6 eV to 2.35 eV with the incorporation of 0.5 wt% CNT. The nonlinear optical transmission of the samples was analyzed at 532 nm using the open-aperture Z-scan technique employing 5 ns laser pulses, revealing a twelve-fold increase in the two-photon absorption coefficient (b) for g-C3N4/CNT0.5 compared to pristine g-C3N4. Remarkably, g-C3N4/CNT0.5 showed enhanced photocatalytic efficiency in degrading bisphenol A (BPA), with the kinetic constant (k) being ten times higher than that of pure g-C3N4. The improved photocatalytic performance of g-C3N4/CNT0.5 is attributed to the presence of CNTs, which act as effective electron acceptors and transfer channels, significantly enhancing the separation of photogenerated charge carriers in g-C3N4, as evidenced by the decreased intensity in the photoluminescence spectrum.

A New Diffusion Strategy Using an Epidemic Spreading Model for Encryption.

The diffusion phenomenon that exhibits intrinsic similarities is pervasive in cryptography and natural systems, evident in liquid diffusion, epidemic spread, animal migration, and encryption techniques. In cryptography, bytes are systematically diffused in a sequential manner to encrypt the value of each byte in the plaintext in a linear fashion. In contrast, within an epidemic spreading model, the diffusion process can be represented within a complex, multilayered network, encompassing layers such as familial and social transmission dynamics. Transmission links establish connections both within and between individual layers. It has had a more rapid spread than linear approaches due to the particularization of non-linear transmission. In this study, the novelty of a cryptography diffusion strategy based on an epidemic model is first proposed, in which pixels and their dynamic adjacency are considered as vertices and edges, respectively, within a complex network framework. Subsequently, the encryption process is governed by the Susceptible-Vaccinated-Infected-Recovered (SVIR) model integrated with chaotic dynamics. Simulation results demonstrate that the proposed algorithm exhibits faster encryption speed while effectively resisting brute force, statistical, and differential attacks. Furthermore, it demonstrates strong robustness against noise interference and data loss.

Applying Super-Resolution and Tomography Concepts to Identify Receptive Field Subunits in the Retina.

Spatially nonlinear stimulus integration by retinal ganglion cells lies at the heart of various computations performed by the retina. It arises from the nonlinear transmission of signals that ganglion cells receive from bipolar cells, which thereby constitute functional subunits within a ganglion cell's receptive field. Inferring these subunits from recorded ganglion cell activity promises a new avenue for studying the functional architecture of the retina. This calls for efficient methods, which leave sufficient experimental time to leverage the acquired knowledge for further investigating identified subunits. Here, we combine concepts from super-resolution microscopy and computed tomography and introduce super-resolved tomographic reconstruction (STR) as a technique to efficiently stimulate and locate receptive field subunits. Simulations demonstrate that this approach can reliably identify subunits across a wide range of model variations, and application in recordings of primate parasol ganglion cells validates the experimental feasibility. STR can potentially reveal comprehensive subunit layouts within only a few tens of minutes of recording time, making it ideal for online analysis and closed-loop investigations of receptive field substructure in retina recordings.

Study of resistive properties and neural response of ZrO2/TiO2 heterojunction nanowire array (NWA) RRAM

Nowadays, the researcher has an eye on enhancing the performance of resistive random-access memory (RRAM) and exploring new demands and applications, particularly in the field of artificial intelligence and neural computing. It is crucially important for accurately replicating the observed plasticity within synapses to achieve superior RRAM performance in low-dimensional nanomaterials. In this work, we focus on addressing certainly unsatisfactory electrical properties of RRAM based on titanium oxide nanowire array (TiO2 NWA), for example, short retention time (∼103 s). Theoretically and experimentally, a novel and solution-based RRAM structure, namely ZrO2/TiO2(NWA), has been conducted. With the help of the ZrO2 insertion layer, the RRAM device shows impressive resistive switching characteristics, including 200 current–voltage(I-V) sweeps without degradation, increased cycling endurance (>105 cycles), and a long retention time (∼9 × 104 s). These findings hold significant implications for digital computing systems. Moreover, the successful implementation of the proposed device enables the emulation of fundamental synaptic biological features such as non-linear transmission properties, learning experiences behavior, short-term potentiation (STP) and long-term potentiation (LTP). This research provides evidence of the immense potential of the Ag/ZrO2/TiO2(NWA)/FTO RRAM device in bipolar non-volatile memory (NVM) and biomimetic neuromorphic systems.

Application of cross-channel multiscale permutation entropy in measuring multichannel data complexity.

Entropy is a pivotal concept in nonlinear dynamics, revealing chaos, self-organization, and information transmission in complex systems. Permutation entropy, due to its computational efficiency and lower data length requirements, has found widespread use in various fields. However, in the age of multi-channel data, existing permutation entropy methods are limited in capturing cross-channel information. This paper presents cross-channel multiscale permutation entropy algorithm, and the proposed algorithm can effectively capture the cross-channel information of multi-channel dataset. The major modification lies in the concurrent frequency counting of specific events during the calculation steps. The algorithm improves phase space reconstruction and mapping, enhancing the capability of multi-channel permutation entropy methods to extract cross-channel information. Simulation and real-world multi-channel data analysis demonstrate the superiority of the proposed algorithm in distinguishing different types of data. The improvement is not limited to one specific algorithm and can be applied to various multi-channel permutation entropy variants, making them more effective in uncovering information across different channels.

Nonlinearity-tolerant transmission using modified phase-conjugate twin wave for M-PSK signals

Abstract Using modified phase-conjugate twin wave (M-PCTW) scheme, in which additional information bits are modulated one of the conjugated wave, is helpful to increase the spectral efficiency (SE) of the conventional PCTW scheme. In this paper, we show that the phase modulated formats, but not the conventional square QAM formats are more suitable to M-PCTW scheme. Results of 1600 km nonlinear transmission show that for polarization multiplexed (PM) 8-PSK format, performance improvement from M-PCTW is about 3.3 dB, while it is about 2.2 dB for PM 8-QAM formats. For PM 16-PSK (QAM) modulation, performance improvement from M-PCTW is about 3.4 dB and 1.6 dB, respectively.

Quadruple impact of SPM, XPM, FWM and SRS nonlinear impairments on the performance of DWDM-PON

Recently, dense wavelength division multiplexing passive optical networks (DWDM-PONs) have become a considerable choice for 5G and beyond fronthaul implementations. Formerly, we have proposed a full-duplex bidirectional DWDM-PON architecture convenient for those implementations and analyzed the combined dual impact of four-wave mixing (FWM) and stimulated Raman scattering (SRS) nonlinear impairments on the proposed architecture. Meanwhile, a detailed literature analysis showed us that the combined quadruple impact of self phase modulation (SPM), cross phase modulation (XPM), FWM and SRS on the performance of bidirectional DWDM-PONs have never been researched up to now. In this paper, quadruple impact of SPM, XPM, FWM and SRS on the performance of both uplink channels (ULCs) and downlink channels (DLCs) of the formerly proposed DWDM-PON has been analyzed with simulations. Simulations have been performed in O-band region for ULCs and in C-band region for DLCs of 2 × 15- and 2 × 63-channel DWDM-PONs having 12.5 GHz, 25 GHz, 50 GHz, 100 GHz equally-spaced channels. The quadruple impact of optical nonlinear impairments on the DWDM-PON performance has been analyzed with signal-to-crosstalk ratio (SXR) simulations performed under varying channel input powers and channel lengths. Results show that under the quadruple nonlinear impact reliable bidirectional transmission with an SXR over 23 dB can be achieved for channel input powers below 0.58 mW and 0.16 mW in 2 × 15- and 2 × 63-channel DWDM-PONs, respectively, for all channel spacing values and 25 km transmission lengths. Moreover, results also imply that variations in channel lengths do not significantly affect SXR at both ULCs and DLCs of 2 × 15- and 2 × 63-channel DWDM-PONs for lengths exceeding 50 km. The thorough analysis presented in the paper will give a new insight for analysis of conventional and next generation PONs.

Bolt-loosening Fault Diagnosis in Rotor Systems with Nonlinear Vibration Transmissibility Function-based Features and Indexes

Bolt-loosening Fault Diagnosis in Rotor Systems with Nonlinear Vibration Transmissibility Function-based Features and Indexes

Diverse soliton solutions to the nonlinear partial differential equations related to electrical transmission line

This paper introduces novel traveling wave solutions for the (1+1)-dimensional nonlinear telegraph equation (NLTE) and the (2+1)-dimensional nonlinear electrical transmission line equation (NETLE). These equations are pivotal in the transmission and propagation of electrical signals, with applications in telegraph lines, digital image processing, telecommunications, and network engineering. We applied the improved tanh technique combined with the Riccati equation to derive new solutions, showcasing various solitary wave patterns through 3D surface and 2D contour plots. These results provide more comprehensive solutions than previous studies and offer practical applications in communication systems utilizing solitons for data transmission. The proposed method demonstrates an efficient calculation process, aiding researchers in analyzing nonlinear partial differential equations in applied mathematics, physics, and engineering

Electrically Tunable Diode-Based Nonlinear Transmission Line

Electrically Tunable Diode-Based Nonlinear Transmission Line

Stability analysis of a nonlinear malaria transmission epidemic model using an effective numerical scheme

Malaria is a fever condition that results from Plasmodium parasites, which are transferred to humans by the attacks of infected female Anopheles mosquitos. The deterministic compartmental model was examined using stability theory of differential equations. The reproduction number was obtained to be asymptotically stable conditions for the disease-free, and the endemic equilibria were determined. More so, the qualitatively evaluated model incorporates time-dependent variable controls which was aimed at reducing the proliferation of malaria disease. The reproduction number R o\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\left(o\\right)$$\\end{document} was determined to be an asymptotically stable condition for disease free and endemic equilibria. In this paper, we used various schemes such as Runge–Kutta order 4 (RK-4) and non-standard finite difference (NSFD). All of the schemes produce different results, but the most appropriate scheme is NSFD. This is true for all step sizes. Various criteria are used in the NSFD scheme to assess the local and global stability of disease-free and endemic equilibrium points. The Routh–Hurwitz condition is used to validate the local stability and Lyapunov stability theorem is used to prove the global asymptotic stability. Global asymptotic stability is proven for the disease-free equilibrium when R0≤1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${R}_{0}\\le 1$$\\end{document}. The endemic equilibrium is investigated for stability when R0≥1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${R}_{0}\\ge 1$$\\end{document}. All of the aforementioned schemes and their effects are also numerically demonstrated. The comparative analysis demonstrates that NSFD is superior in every way for the analysis of deterministic epidemic models. The theoretical effects and numerical simulations provided in this text may be used to predict the spread of infectious diseases.

Qualitative properties of solutions to a nonlinear transmission problem for an elastic Bresse beam

We consider a nonlinear transmission problem for a Bresse beam, which consists of two parts, damped and undamped. The mechanical damping in the damping part is present in the shear angle equation only, and the damped part may be of arbitrary positive length. We prove the well-posedness of the corresponding system in energy space and establish the existence of a regular global attractor under certain conditions on the nonlinearities and coefficients of the damped part only. Besides, we study the singular limits of the problem under consideration when curvature tends to zero, or curvature tends to zero, and simultaneously shear moduli tend to infinity and perform numerical modeling for these processes.

An improved transmission efficiency prediction method for nonlinear characteristics of the cycloid reducer

This study aims to accurately predict the nonlinear characteristics of transmission efficiency of cycloid reducers under different operating conditions. Firstly, equivalent modeling of the multi-source errors (MSEs) in the designed cycloid reducer is conducted. Force analysis algorithms considering MSEs are proposed for the cycloid drive mechanism, the output mechanism, and the bearings. Secondly, mathematical models are established for the load-dependent power losses, while an equivalent test is used for modeling load-independent power losses. Subsequently, an improved transmission efficiency prediction (TEP) method for cycloid reducers is proposed, which is then applied to the performance prediction of a prototype under different operating conditions. The advantages of the improved TEP method over the conventional method are discussed, and the influences of MSEs and load-independent power losses on the nonlinear characteristics of transmission efficiency are summarized. Finally, tests are conducted for the reducer prototype, and the test results are found to be in good agreement with the results obtained by the proposed TEP method. The main contribution of this study is to establish a solid algorithmic and modeling foundation for the optimal design of nonlinear transmission efficiency in cycloid reducers and provide reliable guidance for their engineering applications.

Superlinear transmission in an indirect signal production chemotaxis system

In this paper, the indirect signal production system with nonlinear transmission is considered ut=Δu−∇⋅(u∇v),vt=Δv−v+w,wt=Δw−w+f(u)in a bounded smooth domain Ω⊂Rn (n≥1) associated with homogeneous Neumann boundary conditions, where f∈C1([0,∞)) satisfies 0≤f(s)≤sα with α>0. It is known from [1] that the system possesses a global bounded solution if 0<α<4n when n≥4. In the case n≤3 and if we consider superlinear transmission, no regularity of w or v can be derived directly. In this work, we show that if 0<α<min{4n,1+2n}, the solution is global and bounded via an approach based on the maximal Sobolev regularity.

Solitary waves of M-fractional low-pass nonlinear electrical transmission line model arising in network system

In this study, we analyze the solitary wave behavior of a truncated M-fractional low-pass nonlinear electrical transmission line (NLETLs) model. NLETL models are relevant to computer network systems, particularly for high-speed data transmissions. They influence the behavior of signals traveling through network cables. To investigate the dynamics of solitary waves in the model, we applied the modified Sardar sub-equation and extended the sinh-Gordon equation expansion methods. We illustrated the 2D, 3D, and contour shapes of selected solutions for appropriate values of the NLETLs dynamics using Mathematica-14. Kink, anti-kink, bright-dark bell, dark bell, M-shaped periodic soliton, and logarithmic wave solutions were obtained. The results indicate that the proposed techniques may provide valuable, powerful, and efficient insights into the dynamics of nonlinear evolution models. The role of the fractional order derivative in making optical solutions is investigated in detail, which opens up opportunities for the creation of more complex models that can more accurately simulate optical phenomena in the real world.

Investigation of solution structures in a nonlinear electric transmission network incorporating dissipative elements through physical phenomena analysis

This paper presents an innovative approach to solving the voltage equation in a multi-coupled nonlinear transmission network with dissipative elements. By employing the G′G2 -expansion method and fractional derivatives, we explore the behavior of current and voltage, considering memory effects. Our investigation delves into the impact of fractional calculus on signal transmission, revealing insights into period, amplitude, and propagation direction. Additionally, we analyze the influence of obliqueness angles and various fractional-order derivatives on voltage waveforms Stability analysis demonstrates the significant role of dissipative elements and modulation parameters on signal stability and network resistance to interference. Furthermore, we examine the effects of free parameters on signal transmission characteristics. Our findings highlight the intricate interplay between fractional order, wave obliqueness, and physical parameters on voltage propagation, addressing gaps in previous research.

Security Capacity by Nonlinear Transmission in MIMO Systems for Physical Layer Security

Security Capacity by Nonlinear Transmission in MIMO Systems for Physical Layer Security