Major Axis Of Ellipse Research Articles

Colored rice quality inspection system using machine vision

The machine vision-based quality evaluation of colored rice is an important component of achieving automatic rice production and processing. This study took red indica rice as the research object and developed a machine vision system for inspecting flawed rice kernels that are broken, chalky, damaged or spotted. Near infrared images of colored rice samples were collected by the machine vision system. A support vector machine (SVM) classifier, with the input of the invariant moment ellipse major axis, was applied to identify the broken rice kernels in the images. Then, the head rice images were obtained, and another SVM performed the gray-level segmentation. The segmented areas were doubly examined using the centroid distance constraint and the pixel search positioning method, which allowed the chalky areas to be accurately extracted. Finally, the damaged and the spotted areas on the rice kernels were detected by using edge detection and morphological methods. The experimental results show that the recognition accuracy for broken kernels, chalkiness, and damaged and spotted areas reached 99.3%, 96.3% and 93.6%, respectively. In addition, the average running time of the proposed method was 0.15 s, with four types of defects detected at one-time. Hence, it was concluded that the proposed method has significant potential to be applied for rapid and accurate colored rice quality detection and to provide technical support for the machine vision-based inspection of the automated grading of rice.

Точные решения для локальных параметров поляризационных мод в намотанных на катушку spun-световодах с сильным невозмущенным линейным двулучепреломлением. I. Нерезонансная линейная трансформация

The propagation of monochromatic radiation is considered in coiled spun-light guides. It is shown that the local parameters of the elliptic polarization modes, the elliptical birefringence and the angle of ellipticity, are the sum of the constant and variable components. The latter varying in accordance with the harmonic law of the fiber length and the magnitudes of the constant components are substantially larger than the amplitudes of the variable components. It is also shown that the dependence of the local azimuth of the ellipse major axis of eigenpolarization modes increases almost linearly.

Characterization of Voltage Dips and Swells in a DG-Embedded Distribution Network During and Subsequent to Islanding Process and Grid Reconnection

Stand-alone operation of distributed generations (DGs) under an islanded mode is achieved by appropriate switching of controllers from grid-parallel to stand-alone mode. Conversely, during grid restoration, reverse switching operation is employed. These operations cause voltage quality issues; among these issues, voltage dips and swells are two crucial events that are encountered during and subsequent to islanding. This paper characterizes the voltage dips and/or swells caused by the islanding of DG and its subsequent pre- and post-islanding events. Pre-islanding events encompass the fault-initiated islanding scenarios, whereas postislanding events are associated with transitional state, island stabilization, and grid-reconnection states. Considering pre- and post-islanding scenarios, this paper classifies and characterizes the voltage dips and swells using an algorithm incorporating three-phase voltage ellipse and three-dimensional (3-D) polarization ellipse parameters. Three-phase voltage ellipse parameters, namely, major axis, minor axis, and inclination angle of an ellipse, are exploited for characterization and classification of voltage dips/swells based on their affected phases, whereas 3-D polarization ellipse parameters are employed for classifying seven dip types, namely, A, B, D, F, E, C, and G. Islanding and its subsequent scenarios are simulated using a test distribution network of Australia embedded with DG, and the voltage dips and swells are characterized using the proposed algorithm.

ПРИМЕНЕНИЕ ТЕОРИИ ПЛАСТИЧНОСТИ ДИЛАТИРУЮЩИХ СРЕД К ПРОЦЕССАМ УПЛОТНЕНИЯ ПОРОШКОВ МЕТАЛЛИЧЕСКИХ СИСТЕМ

The authors carried out the basic parameters calculation of compacting powders of metallic systems (metals, steels, non-ferrous alloys of different alloying systems) during plastic compression deformation. The paper considers variants of calculating the pressures and densities distribution in powder compacts of various cross sections in different coordinate systems. The authors found that the highest density of the rectangular cross-section powder compact after pressing is observed near a die wall under the pressing punch, at the middle of the short side of the rectangle the density is higher than in the middle of the long side; the lowest density is observed at the die wall above the fixed punch, and in the middle of the short side of the rectangle the density is lower than in the middle of the long side; the lowest density under the pressing punch and the highest density over the fixed punch are observed at the centers of the corresponding rectangular sections. It is shown that in elliptical section compacts of the powders of metal systems after pressing at positive value ζ (ζ > 0) the pressure and density at the ends of the ellipse major axis are higher than at the ends of the minor axis and, conversely, when the ζ < 0 pressure and density at the ends of the major axis are less than at the ends of the minor axis. The obtained results can be used to develop low-waste and resource-saving processes and technologies for processing industrial materials under various conditions and states.

Average Depth versus Average Strike-Length of Fissure Veins for Specified Geometries: A Quantitative Approach

Fissure veins are very important source of mineral deposits particularly that of hydrothermal deposits. The average depth vs. average strike-length of fissure vein, which is an interesting topic, was discussed in Bateman (1962). Some say that depth is equal to length while others opined that depth may be equal to half the length. Here the question arises whether the ratio depth/length which is loosely used refers to depth to length at any given point of time or average depth vs. average length on a statistical basis. Infact these are empirical rules. The empirical rules hold good for an average basis only. Such problems are dealt under geometric probability. The ore body is more like a lens. Infact none of these hold good. The authors developed a method statistically for ore bodies of two geometries namely a circle and an ellipse. In the case of ellipse, three cases are considered namely, (i) the major axis of ellipse is horizontal to X – axis (ii) the major axis of ellipse is parallel to Y axis and (iii) the ellipse is inclined and whose major axis makes an angle θ with the X – axis. In any case, only circular ore body is considered in Bateman (1962). In the case of circular body it is shown that the ratio is neither equal to one or ½ as pointed in Bateman (1962).

Mixed convection boundary-layer flow of a viscoelastic fluid due to horizontal elliptic cylinder with constant heat flux

This article presents numerical analysis of mixed convection laminar flow of a second grade viscoelastic fluid due to cylinder of elliptic cross-section with prescribed surface heat flux. Dimensionless non-linear analysis is computed employing Keller-box method. Skin friction coefficient and Nusselt number are emphasized specifically. These quantities are displayed graphically to examine their behavior along the surface of cylinder. The flow and heat transfer rates are carefully judged while varying the important resulting parameters (mixed convection parameter, viscoelastic parameter aspect ratio, etc.) through sketched graphs keeping major axis of ellipse along and perpendicular to the horizontal. These two positions of major axis are termed as blunt and slender orientations, respectively. The values of skin friction and Nusselt number increase with rise in mixed convection parameter. On the other hand, these quantities lessen by increasing the value of viscoelastic parameter.

Polarization dependence of transverse photo-induced voltage in gold thin film with random nanoholes.

Transverse photo-induced voltage (TPIV) in 25 nm-thick Au film with random holes with 100 nm in diameter is measured for linearly, circularly and elliptically polarized light. By rotating the major axis of ellipse of the light, TPIV exhibits specific pattern depending on polarization. The experimental results are readily reproduced by assuming that the angular momentum transfer from the light beam to the film is responsible for TPIV. A novel ellipticity meter is proposed based on this mechanism.

Superconducting Gap Anisotropy in Monolayer FeSe Thin Film.

Superconductivity originates from pairing of electrons near the Fermi energy. The Fermi surface topology and pairing symmetry are thus two pivotal characteristics of a superconductor. Superconductivity in one monolayer (1ML) FeSe thin film has attracted great interest recently due to its intriguing interfacial properties and possibly high superconducting transition temperature over 65K. Here, we report high-resolution measurements of the Fermi surface and superconducting gaps in 1ML FeSe using angle-resolved photoemission spectroscopy. Two ellipselike electron pockets are clearly resolved overlapping with each other at the Brillouin zone corner. The superconducting gap is nodeless but moderately anisotropic, which puts strong constraint on determining the pairing symmetry. The gap maxima locate on the d_{xy} bands along the major axis of the ellipse and four gap minima are observed at the intersections of electron pockets. The gap maximum location combined with the Fermi surface geometry deviate from a single d-wave, extended s-wave or s_{±} gap function, suggesting an important role of the multiorbital nature of Fermi surface and orbital-dependent pairing in 1ML FeSe. The gap minima location may be explained by a sign change on the electron pockets, or a competition between intra- and interorbital pairing.

On harmonic analysis of vector‐valued signals

A vector‐valued signal in N dimensions is a signal whose value at any time instant is an N‐dimensional vector, that is, an element of . The sum of an arbitrary number of such signals of the same frequency is shown to trace an ellipse in N‐dimensional space, that is, to be confined to a plane. The parameters of the ellipse (major and minor axes, represented by N‐dimensional vectors; and phase) are obtained algebraically in terms of the directions of oscillation of the constituent signals, and their phases. It is shown that the major axis of the ellipse can always be determined algebraically. That is, a vector, whose value can be computed algebraically (without decisions or comparisons of magnitude) from parameters of the constituent signals, always represents the major axis of the ellipse. The ramifications of this result for the processing and Fourier analysis of signals with vector values or samples are discussed, with reference to the definition of Fourier transforms, particularly discrete Fourier transforms, such as have been defined in several hypercomplex algebras, including Clifford algebras. The treatment in the paper, however, is entirely based on signals with values in . Although the paper is written in terms of vector signals (which are taken to include images and volumetric images), the analysis clearly also applies to a superposition of simple harmonic motions in N dimensions. Copyright © 2016 John Wiley & Sons, Ltd.

Properties of an Axial Optical Vortex Generated with the Use of a Gaussian Beam and Two Ramps.

The behavior of an axial optical vortex (OV), which is generated with the use of a Gaussian beam and two ramps implemented by a phase-only spatial light modulator (SLM), is studied as a function of the parameters of two ramps. The analytic solution of a wave equation is obtained in the Fresnel approximation for the diffraction of a Gaussian beam on the two-ramp structure. Nonlinear dependences of the ellipticity gamma of the intensity distribution in the OV core, as well as the angle (phi between the x-axis and the major ellipse axis of the vortex core, on the ramp phase gradient K, are analyzed. The values of given parameters obtained in optical and numerical experiments are in good agreement. It is shown that, as the gradients of the phases of two ramps vary in the limits of 3pi rad/cm, the ellipticity and the slope angle of the major axis ellipse are changed, respectively, by 0.3 and 56 degrees. This gives possibility to efficiently control the parameters of OVs.

Machining slight burr formed micro-channels with different moving trajectories of a pyramidal diamond tip

In this study, a tip-based channel fabricating method on aluminum alloy material is studied using different tip moving trajectories. A three-sided pyramidal tip is driven by a three-axis piezoelectric actuator to do the movements of the circle, the sharp ellipse (major axis along the feeding direction), and the flat ellipse (minor axis along the feeding direction) revolutions are the three kinds of moving trajectories used for machining. In each revolution, due to the shapes of tip and moving trajectory, there would be two cutting edges participating in machining process. Under these three trajectories, the variations of uncut chip thickness and cutting rake angle with tip revolving and the cutting length of every edge in each tip revolution are different, which results in different sizes of chips and burrs formed. Effects of these three moving trajectories on the material removal are studied in detail. Through processing experiments, it was found that without any deburring method, the channel machined using the sharp ellipse trajectory has two edges with no burr formed and could obtain better bottom surface quality with a smaller feed rate, while channels machined using the other two both have burrs at the right side, which results from the accumulation of chips. Finally, to eliminate or reduce this chip accumulation further, a three-dimensional moving trajectory is designed as a deburring method and used to process channels. It was found that this deburring method plays a significant role on the circle trajectory, but it is ineffective on the flat ellipse trajectory.

Reliability and Intersession Agreement of Microperimetric and Fixation Measurements Obtained with a New Microperimeter in Normal Eyes

Purpose: To evaluate the reliability and intersession agreement of measurements of retinal sensitivity as well as of the fixation pattern obtained in healthy eyes with a microperimeter integrating the mechanism of the scanning laser ophthalmoscope (SLO) with the static perimetry.Methods: This study included a sample of 44 healthy eyes of 44 subjects of a mean age of 27.0 ± 8.5 years. In all cases, microperimetric exams with the MAIA system (Centervue, Padova, Italy) were performed in three different sessions to evaluate the intersession repeatability. The consistency of measurements was analyzed by using the Friedman test and by analyzing the correlation between consecutive measurements. Agreement between the first and third sessions was assessed by using the Passing–Bablok regression analysis. The following parameters were analyzed: average threshold (AT), macular integrity (MI) index, fixation indexes P1 and P2, bivariate contour ellipse area (BCEA), major and minor axes of the ellipse and high preferred retinal locus position (PRLh).Results: Not statistically significant differences were found in the evaluated parameters between the three sessions (p ≥ 0.193). The correlation between consecutive measurements was moderate to strong for all parameters evaluated (r ≥ 0.49, p < 0.01), except for the MI and the position of the PRLh (r ≤ 0.305, p ≥ 0.05). The Passing–Bablok regression analysis showed a good agreement between the first and third measurement for all parameters, except for the MI and the position of the PRLh.Conclusion: MAIA MP system is able to provide consistent measurements of AT and fixation in normal subjects. MI and the position of PRLh seem to be the least reliable parameters in this group of patients.

Uniform asymptotics of paraxial boundary diffraction waves

Starting from the paraxial formulation of the boundary-diffracted-wave theory proposed by Hannay [J. Mod. Opt. 47, 121-124 (2000)] and exploiting its intrinsic geometrical character, we rediscover some classical results of Fresnel diffraction theory, valid for "large" hard-edge apertures, within a somewhat unorthodox perspective. In this way, a geometrical interpretation of the Schwarzchild uniform asymptotics of the paraxially diffracted wavefield by circular apertures [K. Schwarzschild, Sitzb. München Akad. Wiss. Math.-Phys. Kl. 28, 271-294 (1898)] is given and later generalized to deal with arbitrarily shaped apertures with smooth boundaries. A quantitative exploration is then carried out, with the language of catastrophe optics, about the diffraction patterns produced within the geometrical shadow by opaque elliptic disks under plane wave illumination. In particular, the role of the ellipse's evolute as a geometrical caustic of the diffraction pattern is emphasized through an intuitive interpretation of the underlying saddle coalescing mechanism, obtained by suitably visualizing the saddle topology changes induced by letting the observation point move along the ellipse's major axis.

Laser-induced growth of oriented Sb2S3 single crystal dots on the surface of 82SbSI–18Sb2S3 glasses

To produce ferroelectric single-crystal architecture on glass surface by laser irradiation, usually the starting structure is a dot. Therefore, we have investigated the formation of this basic element of laser-induced crystallization, as an example, on the surface of pseudo binary 82SbSI–18Sb2S3 chalcogenide glass using a diode laser of wavelength λ=520nm. The intensity of the laser was chosen such that the temperature in the crystal growth region was kept below the melting temperature of the glass but high enough to facilitate solid state devitrification. The morphology, crystallinity and composition of crystallized dots were determined using Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-ray Spectroscopy (EDS). We find that Sb2S3 single crystal dots with elliptic cross-section form with <001> direction parallel to the major axis of ellipse and the surface of glass matrix. On the basis of the presented results, we propose that laser heating can be exploited uniquely to grow oriented single crystals of solids.

Correlation between Au Lithogeochemical Anomalies and Fault-density Using Geostatistical and Fractal Modeling in Sharafabad-Hizehjan Area, NW Iran

The aim this study is to examine the correlation between Au lithogeochemical anomalies and density of faults utilizing geostatistical analysis, Concentration-Number (C-N) and Concentration-Area (C-A) fractal models in Hizehjan-SharafAbad area, NW Iran. This area is located in the Alborz-Azerbayjan structural zone and Arasbaran metallogenic belt having an Au epithermal type mineralization. In this study, Au variograms, anisotropic ellipse of Au distribution and rose diagram of fault trends were constructed whose analyses showed good correlation between major axis of ellipse with main trend of faults. Consequently, the C-N and C-A log-log plots were constructed for Au and fault-density distributions which revealed very good correspondence/correlation. The results obtained by fractal models indicate a strong correlation between main Au anomalies, anisotropic ellipse major axis and fault-density distributions.

Analysis of Electric Field Distribution in Capacitors’ Dielectric with Cavities

Cavities in dielectric greatly impair the performance of capacitors, especially the life and so further affect the primary power systems in fusion energy systems. Thus, the electric field distribution in dielectric of capacitors with cavities was studied. A simplified elliptical cavity model in dielectric was built in this paper and finite element analysis was utilized to solve the electric field distribution problem. Simulation results show that the electric field near the cavities will be enhanced with a factor of k. The enhance factor k will rise with the increase of the relative permittivity of capacitors’ dielectric. The influence of the cavities’ shape on enhancement mainly results from the curvature. When the cavities possess higher curvature, the enhancement will be strengthen. Also, the orientation of the cavities affects the electric field significantly. The enhance factor k decreases with the decreasing of the angle between the major axis of ellipse and the external electric field direction.

Natural fertility: Naturopathic treatment of sperm DNA fragmentation and reduced egg reserve

To produce ferroelectric single-crystal architecture on glass surface by laser irradiation, usually the starting structure is a dot. Therefore, we have investigated the formation of this basic element of laser-induced crystallization, as an example, on the surface of pseudo binary 82SbSI–18Sb2S3 chalcogenide glass using a diode laser of wavelength λ = 520 nm. The intensity of the laser was chosen such that the temperature in the crystal growth region was kept below the melting temperature of the glass but high enough to facilitate solid state devitrification. The morphology, crystallinity and composition of crystallized dots were determined using Electron Backscatter Diffraction (EBSD) and Energy Dispersive X-ray Spectroscopy (EDS). We find that Sb2S3 single crystal dots with elliptic cross-section form with <001> direction parallel to the major axis of ellipse and the surface of glass matrix. On the basis of the presented results, we propose that laser heating can be exploited uniquely to grow oriented single crystals of solids.

Effect of Helix Angle on the Stress Intensity Factor of a Cracked Threaded Bolt

The fracture behavior of a crack in a threaded bolt depends on the stress intensity factor (SIF). Available SIF solutions have approximated the threaded bolt as a circular groove, thus, the SIF predominantly corresponds to the opening mode, mode-I. As a thread in a bolt has a helix angle, the crack propagates under mixed mode conditions (opening, sliding and tearing), esp. when the crack sizes are small. This paper presents the results of SIF solutions for a part-through crack emanating from a Metric threaded bolt. A 3D finite element model with preexisting flaws was generated to calculate the SIF values along the crack front. Crack aspect ratios in the range of (0.2 &lt; (a/c) &lt; 1) and crack depth ratios in the range of (0.1 &lt; (a/d) &lt; 0.5) (where “a” is crack length, “c” is semi major axis of ellipse and “d” is minor diameter of the bolt) were considered along the crack plane for the SIF estimation. The SIF values at the midregion decreases with an increase in aspect ratio (a/c), and SIF increases when the crack depth ratio (a/d) increases in the midregion. Close to the free edges, higher SIF values was observed for crack depth and aspect ratios ranging between 0.2 and 0.6 compared to midregion. In the crack surface region, up to a crack depth ratio of 0.25, significant influence of mode-II and mode-III fracture was noted for shallow cracks (a/c &lt; 0.2). Significant influence of mode-II and mode-III fracture was observed for semicircular cracks (a/c = 1) beyond the crack depth ratio of 0.3.

HEAT TRANSFER ENHANCEMENT DUE TO SWIRL EFFECTS IN OVAL TUBES TWISTED ABOUT THEIR LONGITUDINAL AXIS

Periodically fully developed swirl flow and heat transfer in axially helically twisted tubes with elliptical cross sections are computationally modeled. The tubular geometry is described by its twist ratio y (ratio of 180°wist-pitch H to hydraulic diameter dh), and flow cross-section aspect ratio a (ratio of minor to major axis of ellipse). Constant-property flows of water (Prandtl number ~3.0) in the laminar Reynolds number regime (10 ≤ Re ≤ 1000) are considered for several different duct geometries (3.0 ≤ y ≤ 6.0 and 0.3 ≤ α ≤ 0.7). The parametric study delineates the effect of swirl on the velocity distribution, isothermal Fanning friction factor f, the temperature field, and Nusselt number Nu for a tube maintained at a uniform wall temperature (T condition). The dominant vortex structure has a spiral formation with a rotating fluid nucleus and two counter-rotating cells as spiral arms in the flatter section of the oval cross section. Both f and Nu are found to be highest for more tightly twisted tubes (y = 3.0) with a flatter elliptical cross section (α = 0.3). Moreover, relative to an equivalent straight oval tube, up to 2.5 times higher heat transfer rates can be achieved for fixed pumping power to render a more compact heat exchanger with a smaller volume or high surface-area density.

Haptic distal spatial perception mediated by strings: Size at a distance and egocentric localization based on ellipse geometry

Participants explored ellipse perimeters defined by fixed-length strings, held taut by their moving finger, with ends attached to two fixed hooks (foci). Participants haptically judged ellipse interfocal distance (IFD; in effect, exocentric separation, or size at a distance) or location of ellipse major axes (i.e., egocentric localization relative to the moving finger). In Experiment 1A, perceivers made reliable and accurate multialternative forced choice IFD judgments. Experiment 1B showed similar reliability for direct estimations but showed greater scaling error. In Experiment 2, perceivers reliably localized ellipse major axes. Both experiments derived from a priori geometrical analysis, consistent with the Gibsonian perceptual research program and previous string-mediated haptic distal spatial studies. Results are discussed with respect to haptic perception as a telemodality and to dynamic touch.