Radial Line Research Articles

Effect of stimulus size on chromatic discrimination

In psychophysical experiments, discrimination thresholds were measured in different directions around points in the MacLeod–Boynton chromaticity diagram, while the eye was maintained in a state of constant adaptation to a metamer of D65. A spatial forced-choice procedure was used: a brief (150 ms) disk divided into four sectors was presented, and the observers’ task was to detect the sector that differed from the other three. The diameter of the test disk varied from 32 min to 2.4∘ of visual angle. Sensitivity was probed at several different referent positions in the chromaticity diagram, including the adapting chromaticity. The data for each referent were fitted with ellipses. In the case of the largest test size (2.4∘ diameter), ellipses were predominantly oriented so that their longer axis was aligned with the line connecting the center of the ellipse to the chromaticity of D65 (the adaptation point). Along such radial lines, colorimetric purity varies, and the orientation of the ellipses reflects reduced sensitivity to saturation differences compared to hue differences. With decreasing test size, the ellipses change their orientation so that their longer axis is rotated toward a tritan direction, and the detection of changes in chromaticity depends primarily on the activity of long- and middle-wave cones. However, these general principles must be modified in several ways according to the region of the chromaticity diagram that is being probed.

On the Klein–Gordon scalar field oscillators in a spacetime with spiral-like dislocations in external magnetic fields

We investigate the effects of two types of spiral dislocation (the distortion of the radial line, labeled as spiral dislocation I, and the distortion of a circle, labeled as spiral dislocation II) on the relativistic dynamics of the Klein–Gordon (KG) oscillator fields, both in the presence and absence of external magnetic fields. In this context, our investigations show that while spiral dislocation I affects the energies of the KG oscillators (with or without the magnetic field), spiral dislocation II has, interestingly, no effect on the KG oscillator’s energies unless a magnetic field is applied. However, for both types of spiral dislocations, we observe that the corresponding wave functions incorporate the effects of the dislocation parameter. Our findings are based on the exact solvability and conditional exact solvability (associated with the biconfluent Heun polynomials) of the KG oscillators (with or without the magnetic field, respectively) for spiral dislocation I, and the exact solvability of the KG oscillators (with or without the magnetic field) for spiral dislocation II. The exact solvability of the latter suggests that the oscillator’s frequency is solely determined by the magnetic field strength.

Evaluating and extending speedup techniques for optimal crossing minimization in layered graph drawings.

A layered graph is an important category of graph in which every node is assigned to a layer, and layers are drawn as parallel or radial lines. They are commonly used to display temporal data or hierarchical graphs. Previous research has demonstrated that minimizing edge crossings is the most important criterion to consider when looking to improve the readability of such graphs. While heuristic approaches exist for crossing minimization, we are interested in optimal approaches to the problem that prioritize human readability over computational scalability. We aim to improve the usefulness and applicability of such optimal methods by understanding and improving their scalability to larger graphs. This paper categorizes and evaluates the state-of-the-art linear programming formulations for exact crossing minimization and describes nine new and existing techniques that could plausibly accelerate the optimization algorithm. Through a computational evaluation, we explore each technique's effect on calculation time and how the techniques assist or inhibit one another, allowing researchers and practitioners to adapt them to the characteristics of their graphs. Our best-performing techniques yielded a median improvement of 2.5-17× depending on the solver used, giving us the capability to create optimal layouts faster and for larger graphs. We provide an open-source implementation of our methodology in Python, where users can pick which combination of techniques to enable according to their use case. A free copy of this paper and all supplemental materials, datasets used, and source code are available at https://osf.io/5vq79.

A Large-Aperture Multi-Subarray Radial Line Helical Array Antenna with Dielectric Windows for High-Power Microwave Applications

A Large-Aperture Multi-Subarray Radial Line Helical Array Antenna with Dielectric Windows for High-Power Microwave Applications

Dual-Band and Dual-Circularly Polarized Radial Line Slot Array Antenna on Metal Pin Based Slow-Wave PPW Structure

Dual-Band and Dual-Circularly Polarized Radial Line Slot Array Antenna on Metal Pin Based Slow-Wave PPW Structure

One-fifth radial line slot array (RLSA) antennas

ABSTRACT This study introduced the smallest radial line slot array (RLSA) antenna to date and examined the impact of cutting on the antenna’s performance to assess the feasibility of this cutting method. The RLSA model and its cut version were designed, simulated, and fabricated to validate the simulations and the method itself. Their performance was then evaluated in terms of gain, reflection coefficient, and bandwidth. The analysis revealed that the method could reduce the antenna size by up to five times while maintaining its gain, which only decreased by approximately 50%. Additionally, this method resulted in a wider bandwidth of around 1 GHz and significantly reduced reflection.

High Gain Radial Line Slot Array Antenna (RLSA) Integrated with Frequency Selective Surface (FSS) for mm-wave 5G Applications

Abstract The proposed RLSA antenna incorporates a new metamaterial designed at 26 GHz resonance frequency, utilizing a Rogers 5880 substrate layer that has a 1.575 mm thickness. The diameter of the RLSA antenna in Free-space wavelength is 17.34λ0. This RLSA antenna, equipped with a frequency selective substrate (FSS) metamaterial reflector, operates within the frequency range of 22.5 to 30.5 GHz, obtaining a 24.58 dBi realized gain. This development is capable of enhancing the gain and reducing the side lobe level, making it compatible with 5G millimeter-wave applications.

Analysis of the Impact of Photovoltaic Generation on the Level of Energy Losses in a Low-Voltage Network

Due to the dynamic development of energy generation in photovoltaic installations, a reliable assessment of their impact on the level of energy losses in distribution networks is needed. For energy companies managing network resources, this issue has a very tangible practical aspect. Therefore, ongoing analyses of the level of electricity losses based on actual measurement data of prosumers are needed. In the paper, the influence of energy introduced by prosumer photovoltaic installations on energy losses in a low-voltage radial line is investigated. The issue is examined from three perspectives: 1. Focused on energy supplied into the low-voltage grid from photovoltaic installations; 2. the installations’ locations; and 3. the product of energy and distance from the power source. Comparative assessments are made of the examined aspects for 87 possible locations of prosumer installations in the tested low-voltage network. An analysis of energy losses is carried out both for the entire analysed network and separately for the line and the transformer. The changes in energy losses are influenced by both the power and the location of the photovoltaic installations. Based on the research findings, functions defining relative changes in energy losses in the low-voltage network are determined.

Analysis of sealing conditions and axial forces in a three-screw pump

The profile of the three-screw pump is a critical parameter influencing both the accuracy of screw meshing and the pump's longevity. Currently, modifications involving radial straight lines to the pendulum lines are prevalent. This study constructs the tooth profile for the three-screw pump applied in elevator lifting following straight line adjustments. Utilizing meshing theory, it deduces the meshing conditions of the screw surface. Subsequently, the analysis divides the screw into cavities and examines the axial force. This approach offers a theoretical foundation for accurately calculating instantaneous flow, pressure distribution, and volumetric efficiency in three-screw pumps designed for elevator applications.

Supersymmetric Quesne-Dunkl Quantum Mechanics on Radial Lines

Quantum deformations offer valuable perspectives into quantum mechanics, particularly by advancing our understanding of symmetry and algebraic structures.The Dunkl oscillator, which integrates Dunkl operators into the harmonic oscillator framework, advances the system’s algebraic properties and opens new approaches for exploring quantum phenomena. Supersymmetric quantum mechanics (SSQM) unifies bosonic and fermionic aspects and facilitates the construction of solvable models using generalized Dunkl operators. This paper introduces a new approach to the Dunkl oscillator, employing a complex reflection operator to deepen the understanding of its connection to Hermite polynomials on radial lines. The results offer new perspectives on the Dunkl oscillator’s algebraic structure and its relevance to SSQM and quantum deformation theory, expanding the potential for discovering solvable quantum models.

Cortical development in the structural model and free energy minimization.

A model of neocortical development invoking Friston's Free Energy Principle is applied within the Structural Model of Barbas etal. and the associated functional interpretation advanced by Tucker and Luu. Evolution of a neural field with Hebbian and anti-Hebbian plasticity, maximizing synchrony and minimizing axonal length by apoptotic selection, leads to paired connection systems with mirror symmetry, interacting via Markov blankets along their line of reflection. Applied to development along the radial lines of development in the Structural Model, a primary Markov blanket emerges between the centrifugal synaptic flux in layers 2,3 and 5,6, versus the centripetal flow in layer 4, and axonal orientations in layer 4 give rise to the differing shape and movement sensitivities characteristic of neurons of dorsal and ventral neocortex. Prediction error minimization along the primary blanket integrates limbic and subcortical networks with the neocortex. Synaptic flux bypassing the blanket triggers the arousal response to surprising stimuli, enabling subsequent adaptation. As development progresses ubiquitous mirror systems separated by Markov blankets and enclosed blankets-within-blankets arise throughout neocortex, creating the typical order and response characteristics of columnar and noncolumnar cortex.

SonoPrint: Acoustically Assisted Volumetric 3D Printing for Composites.

Advances in additive manufacturing in composites have transformed aerospace, medical devices, tissue engineering, and electronics. A key aspect of enhancing properties of 3D-printed objects involves fine-tuning the material by embedding and orienting reinforcement within the structure. Existing methods for orienting these reinforcements are limited by pattern types, alignment, and particle characteristics. Acoustics offers a versatile method to control the particles independent of their size, geometry, and charge, enabling intricate pattern formations. However, integrating acoustics into 3D printing has been challenging due to the scattering of the acoustic field between polymerized layers and unpolymerized resin, resulting in unwanted patterns. To address this challenge, SonoPrint, an innovative acoustically assisted volumetric 3D printer is developed that enables simultaneous reinforcement patterning and printing of the entire structure. SonoPrint generates mechanically tunable composite geometries by embedding reinforcement particles, such as microscopic glass, metal, and polystyrene, within the fabricated structure. This printer employs a standing wave field to create targeted particle motifs-including parallel lines, radial lines, circles, rhombuses, hexagons, and polygons-directly in the photosensitive resin, completing the print in just a few minutes. SonoPrint enhances structural properties and promises to advance volumetric printing, unlocking applications in tissue engineering, biohybrid robots, and composite fabrication.

Finding The Relationship between Pulsation Motion and Hα Emission Lines on γ Cas using Photometric and Spectroscopic Data

Abstract Pulsating stars show variability in brightness due to changes in their volume. There are two types of pulsation/oscillation: radial and non-radial. Radial oscillation keeps the symmetrical shape of the star, while non-radial oscillation does not. We study a pulsating star: γ Cas, classified as a B0.5 IVe variable star because of its pulsations and also an emission star due to the emission lines in its spectra. When a star pulsates, its atmosphere expands and contracts, potentially leading to the formation of shock waves. Observational features such as discontinuities in the radial velocity curve and emission lines support this phenomenon. In this study, we analyse the relationship between pulsation motion and the H α emission lines of γ Cas using photometric and spectroscopic data. Photometric data is obtained from the BRIght Target Explorer (BRITE) catalog, while spectroscopic data comes from the Be Star Spectra (BeSS) catalog. Both datasets cover the same observational dates: August 28 to October 26, 2015. Confirming the pulsation period of γ Cas at 1.21 days, we also discover an added pulsation period of 10 days from photometric data. To confirm this, we examine spectroscopic data from three specific dates: August 28, September 7, and 27, 2015. Notably, the relative flux of the H α emission lines continue to increase, leading us to conclude that these lines are indeed caused by the pulsation of γ Cas.

Parallel pigmented network in lentigo maligna: a case series and correlation with in vivo reflectance confocal microscopy.

Lentigo maligna (LM) often poses a diagnostic challenge due to its clinical and dermoscopic mimicry of benign lesions, leading to delayed diagnosis. Focal areas of reticular disruption have been described as one of the earliest dermoscopic signs observed. To describe a novel dermoscopic sign in LM, namely the presence of a parallel pigmented network. Case series of 22 histopathologically-proven LM and lentigo maligna melanoma (LMM), diagnosed between 2018 and 2023, at a tertiary centre. All lesions showed a parallel network upon dermoscopy, in the form of parallel reticular lines, light or dark brown in colour, not emanating from the follicle, with an asymmetrical distribution. Reflectance confocal microscopy (RCM) images were reviewed to correlate these areas. The median age of patients was 73 years old. The majority of lesions were in situ (91%) and extrafacial (82%). Lesions showed minimal signs of atypia other than a parallel network and mostly focal erased areas (100%), followed by perifollicular linear projections (18%) and asymmetrical follicular pigmentation (18%). On RCM, focally areas correlated with atypical junctional thickenings distributed in a parallel fashion (100%) and mitochondria-like structures (23%). Most cases (88%) showed atypical cells in the epidermis, mostly in the form of isolated dendritic cells (41%). Parallel network emerges as a potential dermoscopic sign associated with LM. We hypothesize that in early stages of LM transformation, disruption of the reticular network manifests as parallel lines and/or radial perifollicular lines. Validation with larger studies is warranted.

Cost - benefit analysis of DISCOs by Optimal allocation of DGs and DSTATCOM using GTO algorithm

Electric power Distribution Companies (DISCOs) provide low-cost, reliable, and consistent voltage power from distribution substations. DISCOs have radial transmission lines with all buses as load buses and no generating buses. The voltage at each bus decreases, resulting in larger network losses and voltage variations, which lowers DISCO and customer costs and benefits. This study strategically uses Distributed Generation (DGs) and DSTATCOM to optimize cost-benefit analysis and voltage stability for Distribution Companies (DISCOs). We planned DG unit and DSTATCOM deployment using a new and comprehensive Group Teaching Optimization (GTO) method in this study. The algorithm considers Distribution Company and DG Owner profitability simultaneously. Group Teaching Optimization (GTO) is used on a 33-node test system. MATLAB simulations show the GTO's usefulness in Distribution System Operators.

Analytic Hierarchy Process (AHP)-Based Evaluation of Extremely-Low-Frequency Magnetic Field Contribution Rates

The extremely-low-frequency (ELF) magnetic fields of submarines serve as key characteristics for target detection, with their formation mechanisms being complex and diverse. Effectively manipulating a submarine to reduce its magnetic signature is crucial for enhancing its magnetic stealth capabilities. However, current research on the impact of various causative factors is insufficient. This study proposes a contribution rate assessment method based on the Analytic Hierarchy Process (AHP) model, aiming to provide a theoretical basis for effective manipulation. Initially, a thorough analysis of the threat causes of a submarine’s ELF magnetic fields is conducted, and a corresponding hierarchical threat structure model is established. Subsequently, magnetic field signal characteristics generated by different causes are obtained through simulation, and threat matrices and characteristic matrices are constructed. Finally, the contribution rates of different causative magnetic fields to the total magnetic field are calculated, and the simulation results validate the effectiveness of the method. At the stern detection line, the contribution rate of the wake magnetic field is the highest, reaching 0.7649. Along the radial detection line, the contribution rate of the shaft frequency magnetic field is the highest and gradually decays, eventually falling below the wake magnetic field at 150 m and remaining at an approximately 0.5 contribution rate. This study calculates the contribution rates under different operational conditions and detection scenarios, laying a technical foundation for research on the comprehensive active control strategies of submarine ELF magnetic fields in different scenarios.

The Extended Dunkl Oscillator and the Generalized Hermite Polynomials on the Radial Lines

Model of the extended Dunkl oscillator based on Milovanović generalized Hermite polynomials on radial rays is discussed. Simple explicit realization of creation and annihilation operators in terms of difference-differential operators, coherent states are investigated.

Tuberous Sclerosis Complex and the kidneys: what nephrologists need to know.

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterized by the development of hamartomas in the central nervous system, heart, skin, lungs, and kidneys and other manifestations including seizures, cortical tubers, radial migration lines, autism and cognitive disability. The disease is associated with pathogenic variants in the TSC1 or TSC2 genes, resulting in the hyperactivation of the mTOR pathway, a key regulator of cell growth and metabolism. Consequently, the hyperactivation of the mTOR pathway leads to abnormal tissue proliferation and the development of solid tumors. Kidney involvement in TSC is characterized by the development of cystic lesions, renal cell carcinoma and renal angiomyolipomas, which may progress and cause pain, bleeding, and loss of kidney function. Over the past years, there has been a notable shift in the therapeutic approach to TSC, particularly in addressing renal manifestations. mTOR inhibitors have emerged as the primary therapeutic option, whereas surgical interventions like nephrectomy and embolization being reserved primarily for complications unresponsive to clinical treatment, such as severe renal hemorrhage. This review focuses on the main clinical characteristics of TSC, the mechanisms underlying kidney involvement, the recent advances in therapy for kidney lesions, and the future perspectives.

Design of a broadband LNA with multifunction Circuitry based on composite right /left handed transmission lines for impedance matching and suppression of unwanted frequencies

This article presents a low-noise amplifier based on the use of a composite right-left handed transmission line consisting of a single microstrip line and a split ring resonator at the transistor input and output. This design ensures optimum matching over a wide frequency range while eliminating an unwanted frequency band. The circuit is designed to operate at a center frequency of 2.4 GHz while simultaneously eliminating the frequency band around 4.8 GHz, meeting key performance criteria including improved gain, better stability, and significant noise reduction. To achieve these objectives, the transistor used undergoes precise biasing via a DC power supply. In this process, a specifically selected capacitor is arranged in series with a λ/4 transformer. This transformer, in turn, is connected in series to a radial line section. The dimensions of the proposed amplifier are 70 × 34 mm2.For validation purposes, the proposed method was implemented through design, manufacture, and testing. The results obtained show that the proposed low noise amplifier achieves a high gain of 15.27 dB, an input reflection loss S11 of −16.26 dB, an output reflection loss S22 of −13.94 dB, and an inverse isolation S12 of −22.82 dB at 2.4 GHz, with a resonance peak at 4.8 GHz allowing the surrounding frequency band to be eliminated with an attenuation of 77 dB at 4.8 GHz. What's more, the noise figure is kept below 2 dB, with unconditional stability in the desired frequency band.

Пьезоэлектрический дисковый актюатор кручения с дискретно-спиральными электродами

A mathematical model of a disk (ring) torsion actuator with curvilinear interdigital electrodes – «villi» of a spiral form, which are characterized by a constant value of the orientation angle of an arbitrary section of the villus to the circumferential direction of the disk, has been developed. Bases of electrode-villi interacting with each other through local areas of piezoelectric layer are connected with periodic alternation to central or peripheral concentric circular base electrodes, to outputs of which control voltages are connected. As a result of numerical modeling of the «twisting bimorph» graphs of the dependence of the twist angle and the blocking torque on the ratio of the inner and outer radii and the values of the control voltage at the outputs of the base electrodes of the annular two-layer actuator with symmetrical (relative to the radial line) directions of the spiral orientations of the electrode-villi and, as a result, the spiral polarization lines of the piezoelectric layers working for tension/compression.