Discrete Lines Research Articles

A Study of the Soliton Solutions with an Intrinsic Fractional Discrete Nonlinear Electrical Transmission Line

This study aims to identify soliton structures as an inherent fractional discrete nonlinear electrical transmission lattice. Here, the analysis is founded on the idea that the electrical properties of a capacitor typically contain a non-integer-order time derivative in a realistic system. We construct a non-integer order nonlinear partial differential equation of such voltage dynamics using Kirchhoff’s principles for the model under study. It was discovered that the behavior for newly generated soliton solutions is impacted by both the non-integer-order time derivative and connected parameters. Regardless of structure, the fractional-order alters the propagation velocity of such a voltage wave, thus bringing up a localized framework under low coupling coefficient values. The generalized auxiliary equation method drove us to these solitary structures while employing the modified Riemann–Liouville derivatives and the non-integer order complex transform. As well as addressing sensitivity testing, we also investigate how our model’s altered dynamical framework shows quasi-periodic properties. Some randomly selected solutions are shown graphically for physical interpretation, and conclusions are held at the end.

Lane Detection Based on Instance Segmentation of BiSeNet V2 Backbone Network

ABSTRACT Most lane line detection algorithms still have room for improvement in detection accuracy, speed, and robustness. Meanwhile, these algorithms only test the performance indicators through the test set of the open-source dataset rather than deploying them on actual vehicles and evaluating the performance indicators through road scenarios. Therefore, this paper proposes a lane detection algorithm based on instance segmentation. Firstly, a dual-branch neural network model for lane line image segmentation was designed based on BiSeNet V2. Then the discrete lane line feature points are operated through the clustering model. The corresponding feature points are selected for fitting by combining straight lines and curves to obtain the appropriate fitting parameter equation for the specific visual field area. Finally, the model is trained and verified based on the TuSimple dataset. The algorithm has a noticeable performance improvement under the two evaluation indicators of mIoU and FPS. Meanwhile, the model is integrated into the ROS task platform for intelligent vehicles. The results show that the algorithm’s accuracy and detection speed are increased to about 3.9 and 2.9 times, respectively, that of the improved probabilistic Hough transform algorithm under the two evaluation indicators of lateral distance and the detection time of each image frame.

Analysis of Transient Response of ZPW-2000A Jointless Track Circuit Considering Frequency Variation.

In order to accurately analyze the influence of electromagnetic transient signals on the jointless track circuit when the electromagnetic transient signal propagates in the rail, it is necessary to consider the frequency-variable load terminated in the ZPW-2000A jointless track circuit and the frequency-variable loss inside the rail. A method is proposed for calculating the transient response of transmission lines system with frequency-variable end load of jointless track circuit. Firstly, the transmission lines model of jointless track circuit is established, based on multiconductor transmission lines theory, the model equation is deduced and discretized by finite difference time domain (FDTD). The vector fitting method is used to express the admittance of the tuning region in the track circuit, and the rational approximation function of the tuning region is derived from the poles, residues, and constants. The voltage and current at nodes in the tuning region are calculated by piecewise linear recursive convolution algorithm. Combined with the discrete transmission line equation, the current and voltage expression of the transient electromagnetic signal at the receiving end of the track circuit in time domain is obtained. Compared with state variable method, the error is less than 6%, which verifies the correctness of the proposed method. Finally, this paper studies the influence laws of different factors on the overvoltage at the receiving end of jointless track circuit and the weak links of jointless track circuit under the influence of transient electromagnetic signal. It provides theoretical reference for fault research and anti-interference analysis of ZPW-2000A jointless track circuit.

Determining the temperature of aluminum plasma produced by laser‐induced breakdown spectroscopy based on its ultraviolet emission spectra

AbstractPlasma temperature and electron density are two important parameters describing the characteristics of plasma. The Aluminum plasma is produced by laser‐induced breakdown spectroscopy and its emission spectra are observed by a spectrometer with high resolution. Based on its discrete ultraviolet lines, pair‐line Boltzmann (PLB) approach is proposed to determine the temperature of plasma. These pair‐lines are with the same lower electronic state partially immune to self‐absorption influence. For comparison with Boltzmann two‐line method, the Al plasma is prepared at three different pulse energy levels. It is demonstrated that the accuracy of PLB is improved about three times by employing four ultraviolet pair‐lines. The electron density is estimated at different excited energy according to Stark line broadening of Al I 396.15 nm. Furthermore, the alloy of 7075‐Al is used as the sample target to generate the plasma to validate the PLB approach.

Many-Scale Investigations of Deformation Behavior of Polycrystalline Composites: II-Micro-Macro Simultaneous FE and Discrete Dislocation Dynamics Simulation.

The current work numerically investigates commercial polycrystalline Ag/17vol.%SnO composite tensile deformation behavior with available experimental data. Such composites are useful for electric contacts and have a highly textured initial material status after hot extrusion. Experimentally, the initial sharp fiber texture and the number of 3-twins were reduced due to tensile loading. The local inhomogeneous distribution of hardness and Young’s modulus gradually decreased from nanoindentation tests, approaching global homogeneity. Many-scale simulations, including micro-macro simultaneous finite element (FE) and discrete dislocation dynamics (DDD) simulations, were performed. Deformation mechanisms on the microscale are fundamental since they link those on the macro- and nanoscale. This work emphasizes micromechanical deformation behavior. Such FE calculations applied with crystal plasticity can predict local feature evolutions in detail, such as texture, morphology, and stress flow in individual grains. To avoid the negative influence of boundary conditions (BCs) on the result accuracy, BCs are given on the macrostructure, i.e., the microstructure is free of BCs. The particular type of 3D simulation, axisymmetry, is preferred, in which a 2D real microstructural cutout with 513 Ag grains is applied. From FE results, 3-twins strongly rotated to the loading direction (twins disappear), which, possibly, caused other grains to rotate away from the loading direction. The DDD simulation treats the dislocations as discrete lines and can predict the resolved shear stress (RSS) inside one grain with dependence on various features as dislocation density and lattice orientation. The RSS can act as the link between the FE and DDD predictions.

Near-infrared dual-wavelength surface-emitting light source using InAs quantum dots resonant with vertical cavity modes

We developed a compact dual-wavelength surface-emitting light source using InAs quantum dots (QDs) embedded in a vertical cavity (VC). The VC was designed to possess two optical cavity modes that resonate with the discrete emission lines of the QDs. The fabricated light source exhibited significant enhancements in the vertical light emission corresponding to the VC modes. In addition, the light source demonstrated selectivity to the enhanced emission wavelengths with changes in temperature. Compared to conventional dual-wavelength vertical external cavity surface-emitting lasers, these QD-based dual-wavelength emission devices allow for the realization of simple structures because the InAs QDs act as dual-light-emitting materials. These results can be applied to simple dual-wavelength surface-emitting light sources.

Subcellular progression of mesenchymal transition identified by two discrete synchronous cell lines derived from the same glioblastoma

Glioblastomas (GBM) exhibit intratumoral heterogeneity of various oncogenic evolutional processes. We have successfully isolated and established two distinct cancer cell lines with different morphological and biological characteristics that were derived from the same tissue sample of a GBM. When we compared their genomic and transcriptomic characteristics, each cell line harbored distinct mutation clusters while sharing core driver mutations. Transcriptomic analysis revealed that one cell line was undergoing a mesenchymal transition process, unlike the other cell line. Furthermore, we could identify four tumor samples containing our cell line-like clusters from the publicly available single-cell RNA-seq data, and in a set of paired longitudinal GBM samples, we could confirm three pairs where the recurrent sample was enriched in the genes specific to our cell line undergoing mesenchymal transition. The present study provides direct evidence and a valuable source for investigating the ongoing process of subcellular mesenchymal transition in GBM, which has prognostic and therapeutic implications.

Solitary-wave dynamics in an [formula omitted]LC nonlinear transmission line with voltage bias

It was recently established that when an LC transmission line with a Schottky varactor is connected to a voltage terminal, a pulse is formed whose amplitude grows exponentially leading eventually to its instability after some finite propagation time. In the present study an R2LC nonlinear transmission line, consisting of a lumped circuit with unit cells composed of a linear inductance and a linear resistance in the primary branch, and a Schottky varactor shunted with a linear resistance in the secondary branch, all driven by a voltage terminal, is examined. Our objective is to investigate the effects of the competition between the two resistances, on the soliton amplification and propagation characteristics in general, along the nonlinear transmission line. The study is carried out in two steps: first, an analytical study is carried out within the framework of the reductive perturbation theory. This first step leads to a perturbed Korteweg–de Vries equation, in which the two resistances as well as the voltage terminal are regarded as perturbations. It is found that the electrical pulse amplitude is either exponentially amplified or exponentially depressed, depending on a specific relationship between the two resistances and the voltage terminal. Next the discrete line equations are directly solved numerically, assuming the analytically obtained pulse as input signal. This second analysis suggests a complex behaviour of the electrical pulse amplitude, in response to the influence of the two resistances. A particularly interesting behaviour observed in numerical simulations is the decay of a single-pulse soliton with propagation, and its burst into two-pulse and eventually multi-pulse soliton patterns after some finite propagation time. The proposed nonlinear transmission-line model can find widespread applications in complex transmission networks requiring high-power signals, as for instance in wideband and microwave digital signals, wireless, radar and sensor array processings.

Unravelling the anisotropic wetting properties of banana leaves with water and human urine

We report the heterogeneous and anisotropic wetting behaviors of Banana (Musa) leaves on adaxial (top) and abaxial (bottom) surfaces with water and human urine. Both surfaces comprise of varying number densities of micro ridges, micro stomata, micro flakes and nano hairs while the adaxial surface also constitutes discrete visible crest lines. The Wenzel roughness on abaxial and non-crest adaxial are 1.5 ± 0.05 and 1.18 ± 0.008, respectively as measured by combining optical profilometry and atomic force microscopy. A key scientific development in this work is to incorporate the measured Wenzel roughness in the surface energy estimations using Neumann's, Owens-Wendt-Rabel-Kaelble (OWRK) and Wu's models. The surface energy is 29 ± 2 mJ/m2 (OWRK) and 26 ± 1 mJ/m2 (Wu) on the adaxial surface. Nevertheless, the abaxial surfaces are characterized by smaller surface energy values of 20 ± 4 mJ/m2 (OWRK) and 24 ± 3 mJ/m2 (Wu). The measured static contact angles with water and urine are 110 ± 4° and 88 ± 4° (crest line), 130 ± 4° and 107 ± 5° (non-crest adaxial), 121 ± 4° and 120 ± 2° (abaxial) indicating hydrophobicity and urine-phobicity. The water droplets (2.5 to 10 µl) exhibited anisotropic dynamic wettability as they only rolled off parallel to the micro-ridges but stuck when slid perpendicular to the ridges even for specimen tilts up to 90°. Thus, this study unravels the anisotropic wettability of banana leaves due to the presence of micro-ridges which can be biomimicked for providing anisotropic liquid gliding. Also, this can aid in designing the spraying conditions of urine as a natural pesticide/fertilizer in the banana orchards.

Inverse Scattering by Perfectly Electric Conducting (PEC) Rough Surfaces: An Equivalent Model With Line Sources

This paper presents a new method for the reconstruction of the perfectly electric conducting (PEC) rough surface profiles by utilizing electromagnetic waves. The inaccessible rough surface is illuminated by a tapered plane electromagnetic wave and the scattered field data are measured on a certain number of points above the surface under test. The method for the inverse electromagnetic imaging problem is based on a special representation of the scattered field in terms of a finite number of fictitious discrete line sources located along a plane below the rough surface. The current densities of these fictitious sources are obtained through the regularized solution of an ill-posed problem. Then, it is shown that the image of the rough surface can be directly retrieved by seeking the points in the space where the tangential component of the total electric field vanishes. Alternatively, a much more rigorous iterative method based on a regularized Newton algorithm is also presented. A comprehensive numerical analysis is provided to demonstrate the feasibility of the presented approach. In this context, the quantitative successes of both approaches are interpreted by considering a very sensitive ℓ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -norm based error function between the actual and the reconstructed surface profiles. Regarding different scattering scenarios taken into account, the error values obtained for satisfactory reconstructions are generally in the range of 10% - 30% for both methods. It is also shown that the presented algorithms are capable of reconstructing the rough surfaces which oscillate for every λ horizontally and have a peak to peak variation 0.5λ at most.

Discrete Spectrum of Ultralow-Frequency Oscillations of the Ionosphere

This work relates to the field of ultralow-frequency (ULF) spectroscopy of near-earth plasma. Our attention is focused on the Alfvén ionospheric resonator, the spectrum of which is a series of discrete lines. The aim of the study is to experimentally verify a well-defined theoretical prediction. Within the framework of an idealized resonator model, a hypothesis about the relationship between the frequencies of spectral lines has been formulated. To test the hypothesis, observations of ULF oscillations at the mid-latitude Mondy observatory were used. The result of the analysis confirmed the hypothesis that odd harmonics of the resonator discrete spectrum are observed on the earth’s surface. In conclusion, the possibilities of ULF spectroscopy for remote sensing of the ionosphere are briefly discussed.

Ion-photon emission from titanium target under ion beam sputtering

Ion photon emission in the wavelength range of 280 - 420 nm resulting from 5 Kr+ ion beam sputtering from titanium in the presence and the absence of oxygen was studied experimentally. The observed spectra consist of a series of discrete lines superimposed with a broadband continuum. Discrete lines are attributed to excited neutral Ti I and excited ions Ti II. The differences in the observed intensities of spectral lines are discussed in terms of the electron-transfer processes between the excited sputtered atom and electronic levels of the solid. The radiative dissociation process and breaking of chemical bonds seem to contribute to the enhancement of emitted photons intensity. Continuum radiation was observed and is very probably related to the electronic structure of titanium. The collective deactivation of 3d-shell electrons appears to play a role in the emission of this radiation.

Central and Periodic Multi-Scale Discrete Radon Transforms

The multi-scale discrete Radon transform (DRT) calculates, with linearithmic complexity, the summation of pixels, through a set of discrete lines, covering all possible slopes and intercepts in an image, exclusively with integer arithmetic operations. An inversion algorithm exists and is exact and fast, in spite of being iterative. In this work, the DRT forward and backward pair is evolved to propose two faster algorithms: central DRT, which computes only the central portion of intercepts; and periodic DRT, which computes the line integrals on the periodic extension of the input. Both have an output of size N×4N, instead of 3N×4N, as in the original algorithm. Periodic DRT is proven to have a fast inversion, whereas central DRT does not. An interesting application of periodic DRT is its use as building a block of discrete curvelet transform. Central DRT can provide almost a 2× speedup over conventional DRT, probably becoming the faster Radon transform algorithm available, at the cost of ignoring 15% of the summations in the corners.

Large-Scale Transcriptional Profiling of Molecular Perturbations Reveals Cell Line Specific Responses and Implications for Environmental Screening

Cell-based bioassays represent nearly half of all high-throughput screens currently conducted for risk assessment of environmental chemicals. However, there has long been a concern about the sensitivity and heterogeneity among cell lines, which were explored only in a limited manner. Here, we address this question by conducting a large-scale transcriptome analysis of the responses of discrete cell lines to specific molecules. We report the collections of >223 300 gene expression profiles from a wide array of cell lines exposed to 2243 compounds. Our results demonstrate distinct responses among cell lines at both the gene and the pathway levels. Temporal variations for a very large proportion of compounds occur as well. High sensitivity and/or heterogeneity is either cell line-specific or universal depending on the modes of action of the compounds. Among 12 representative pathways analyzed, distinct cell-chemical interactions exist. On one hand, lung carcinoma cells are always best suited for glucocorticoid receptor agonist identification, while on the other hand, high sensitivity and heterogenic features are universal for histone deacetylase inhibitors and ATPase inhibitors. Our data provide novel insights into the understanding of cell-specific responses and interactions between cells and xenobiotics. The findings have substantial implications for the design, execution, and interpretation of high-throughput screening assays in (eco)toxicology.

Measurement of refractive index spectrum of optical material by phase detection with optical coherence tomography

Refractive index (RI) is a fundamental parameter of optical material, and RI spectrum (RIS) is essential for many fields. Current RI measurement is only for some discrete spectral lines, and has extremely high requirements on measurement operation and accuracy. A measurement method of continuous RIS distribution in a wide spectral range was proposed in this work. A swept-source optical coherence tomography using a Mach-Zehnder configuration was used to detect interference spectrum signal, which phase was obtained by using Hilbert transform. By detecting the sample-induced phase and using the proposed equations, RIS of a sample could be obtained. Five measurements on the RIS distributions of two optical materials were conducted for a spectral range of 90 nm, and the results were in agreement with the theoretical distributions, verifying the method's validity. Its principle and operation are simple, and system has the potential to be miniaturized, making it possible to become a useful tool for RIS measurement, especially in some special occasions.

Electrochemical Impedance Spectroscopy with Discrete Transmission Line Model and Electric Circuit Simulation for Current Distribution in Electrode of All Solid–State Battery

The commercialization of all solid–state batteries (ASSBs) incorporating inorganic solid electrolyte (SE) is an earnest desirefor energy–sustainable mobility because of their higher energy density and safer behavior compared to lithium–ion batteries (LIBs).One of the challenges for practical application of ASSBs is to fabricate thick electrode. The transport number of lithium-ions in ASSBs is nearly equal to 1, which theoretically could facilitate a fast charge-discharge reactions during cycling and ignore the overvoltage derived from the concentration gradient of lithium ions in the cell. However, the battery performance with ASSBs typically decreases with an increase in the electrode thickness. Besides active materials and electrical conductive materials, SEs are generally added as an anode/cathode material to promote the ionic conductivity. Unlike liquid electrolytes, it is hard to make a good reaction interface between SE and active materials in ASSBs, which might be the reason for the poor battery performance in thick electrode. However, the bottle–neck part of electrochemical reactions in thick electrodes are still under debate as it stands right now. Electrochemical impedance spectroscopy (EIS) is widely used for the analysis of LIB electrodes, which can divide complicated electrochemical reaction into elemental processes of electrochemical reaction based on their characteristic time constants. We have reported 3D structured electrodes can be analyzed by optimizing equivalent circuits [1–3]. For the most part, a transmission line model has been used to analyze electrodes with reaction distribution in depth-direction. This model is based on the assumption where each resistivity such as ionic resistance and charge transfer resistance is constant regardless of the location in the electrode. Therefore, it cannot express the real situation if the resistance changes by the locations in depth-direction.In this study, we firstly applied a discrete transmission line model (DTLM), in which all parameters in the equivalent circuit are variable for the evaluation of thick electrode. In addition, we simulated the current distribution in the electrode by using calculated parameters from DTLM.EIS measurement was carried out for the all solid–state half–cell composed of NMC cathode (~45 μm-thick)/sulfide–based SE/InLi counter electrode, and the obtained impedance was analyzed using DTLM. In DTLM, we divided the cathode into three layers and set the equivalent circuit as shown in Figure 1 (a). The current distribution in the cathode was also simulated by LTSPICE software.Figure 1 (b) shows Nyquist plots of the solid–state half–cell. The result confirms that Nyquist plots from experimental data were fitted well using the equivalent circuit with DTLM. The parameters obtained by the fitting are used for simulation of the current distribution. In order to adapt for electrical circuit simulation, the equivalent circuit with the parallel connection of R-C series circuits was designed instead of diffusion impedance expressed as constant phase element (CPE). In this case, the simulated current distribution indicates that the current in the cathode preferably flows near the SE side and deceases with approaching to the current collector.In the presentation, we will show the more details in current distribution and demonstrate DTLM can be an promising analytical tool to understand the bottle–neck electrochemcal reactions in ASSBs.

Quantitative Cell Subset Analysis Using Antibody Microarrays.

The expression patterns of surface antigens are associated with the differentiation status and functional characteristics of mammalian cells. To analyze the surface antigen expression pattern in a high-throughput manner, antibody microarrays have been developed by several groups, including ours. This analysis can be performed using cell-binding assays on microarrays; moreover, this approach has advantages over conventional flow cytometry (FCM). Unlike FCM, the microarray-based method cannot evaluate the concurrent expression of more than two surface antigens on a single cell, and therefore, it cannot be used for cell subset analysis. To overcome this drawback, we prepared an antibody microarray with spots presenting co-immobilized multiple antibodies together with spots presenting each antibody separately. The co-immobilized spots are expected to be reactive for every surface antigen specific to the co-immobilized antibodies. In addition, the concept of an algebra of sets is incorporated into the derivation of quantitative data regarding cell subsets. Here, taking cell subsets with respect to two surface antigens as the simplest example, antibody microarrays were prepared and initially subjected to validation studies to verify the accuracy of cell-binding assays. Quantitative subset analysis was performed using antibody microarrays prepared using the anti-CD13 and anti-CD49f antibodies. For model populations that consisted of discrete subsets, THP-1, HL-60, CCRF-CEM, and Ramos cell lines were used because they were found by FCM to have a singular phenotype, that is, CD13+CD49f+, CD13+CD49f-, CD13-CD49f+, and CD13-CD49f-, respectively. Five populations were prepared by mixing these cells at various ratios and analyzed for their subsets using microarrays. The results showed that the experimentally determined abundance ratios of the four model subsets were in good agreement with the predetermined abundance ratios, which provided the proof of principle for the new method in the quantitative subset analysis.

Real time display with the ferrolens of homogeneous magnetic fields

In our previous published research we have studied the applications of the ferrolens for the observation and qualitative analysis of non-homogeneous magnetic fields. Latest developments over the last few years of the ferrolens increased multifold the sensitivity of this device allowing it to display magnetic fields as low as 10mT in strength and therefore it is possible now to observe also the homogeneous (i.e. straight parallel magnetic flux lines of uniform density in space) magnetic field existing inside air solenoids and between N-S poles of two attracting separated permanent magnets. We present and analyze herein these novel observations of homogeneous magnetic fields with the ferrolens and as a potential new application of this device. The ferrolens can now display the projected magnetic field on air from a distance without needing to be in physical contact with the field source. Experiments were carried out to demonstrate these new capabilities of the ferrolens as a nanomagnetic flux viewer, real-time physical device and scientific qualitative tool. We compare the geometry of magnetic fields of condensed matter ferromagnets with that of magnetic fields inside electrical air solenoids. Specifically, the homogeneous field between two N-S attracting magnets at a distance as well as inside air solenoids and Helmholtz coils and also the non-homogeneous total field of single dipole permanent magnets were observed using a latest generation very sensitive ferrolens. The unique feature of this magneto optic fluid thin film physical device is that it can display discrete magnetic flux lines of the macroscopic field. Also we show how the ferrolens can be used to detect qualitatively the symmetry center of a non ideal homogeneous magnetic field.

Soliton Waves in Lossy Nonlinear Transmission Lines at Microwave Frequencies: Analytical, Numerical and Experimental Studies

In this paper, we performed analytical, numerical and experimental studies on the generation of soliton waves in discrete nonlinear transmission lines (NLTL) with varactors, as well as the analysis of the losses impact on the propagation of these waves. Using the reductive perturbation method, we derived a nonlinear Schrödinger (NLS) equation with a loss term and determined an analytical expression that completely describes the bright soliton profile. Our theoretical analysis predicts the carrier wave frequency threshold above which a formation of bright solitons can be observed. We also performed numerical simulations to confirm our analytical results and we analyzed the space–time evolution of the soliton waves. A good agreement between analytical and numerical findings was obtained. An experimental prototype of the lossy NLTL, built at the discrete level, was used to validate our proposed model. The experimental shape of the envelope solitons is well fitted by the theoretical waveforms, which take into account the amplitude damping due to the losses in commercially available varactors and inductors used in a prototype. Experimentally observed changes in soliton amplitude and half–maximum width during the propagation along lossy NLTL are in good accordance with the proposed model defined by NLS equation with loss term.

Two-Stage Clock-Free Time-to-Digital Converter Based on Vernier and Tapped Delay Lines in FPGA Device

This article presents an idea, design and test results of a new time-to-digital converter (TDC) implemented in an FPGA device. The high resolution of 13 ps and measurement range of 3.4 ns are achieved based on a two-stage time interpolation (TI). In the first and second stages of the TI we have used the Vernier delay line and a single tapped delay line, respectively. This solution provides respectable metrological parameters without the need to use a clock signal, and significantly saves the logical resources of an integrated circuit (IC). The proposed method, generally based on two different variants of the discrete delay line, is easy to design and implement in digital ICs. For experimental verification, the TDC was implemented in a single programmable device from family Virtex-7 (Xilinx).