Статті в журналах: "Elliptic curve determined in three dimensions"

1

Huang, Zhi Dong, An Min Hui, Peng Chen, and Yu Wang. "Computer Aided Design and Three-Dimensional Modeling of High-Order Deformed Elliptical Gear." Applied Mechanics and Materials 391 (September 2013): 178–81. http://dx.doi.org/10.4028/www.scientific.net/amm.391.178.

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The characteristics of high-order deformed elliptical gear is analyzed. The parameters of high-order deformed elliptical gear are chosen and calculated. The modeling method of high-order deformed elliptical gear is presented. The shape of pitch curve is determined. The position and orientation of gear teeth are clarified. The three-dimensional solid model of high-order deformed elliptical gear is achieved. The method and the result facilitate finite element analysis and numerical control machining simulation of high-order deformed elliptical gear.

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2

Sun, Yi-Sui. "On the Measure-Preserving Mappings with Three-Dimensions." International Astronomical Union Colloquium 132 (1993): 73–89. http://dx.doi.org/10.1017/s0252921100065957.

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AbstractWe have systematically made the numerical exploration about the perturbation extension of area-preserving mappings to three-dimensional ones, in which the fixed points of area preserving are elliptic, parabolic or hyperbolic respectively. It has been observed that: (i) the invariant manifolds in the vicinity of the fixed point generally don’t exist (ii) when the invariant curve of original two-dimensional mapping exists the invariant tubes do also in the neighbourhood of the invariant curve (iii) for the perturbation extension of area-preserving mapping the invariant manifolds can only be generated in the subset of the invariant manifolds of original two-dimensional mapping, (iv) for the perturbation extension of area preserving mappings with hyperbolic or parabolic fixed point the ordered region near and far from the invariant curve will be destroyed by perturbation more easily than the other one, This is a result different from the case with the elliptic fixed point. In the latter the ordered region near invariant curve is solid. Some of the results have been demonstrated exactly.Finally we have discussed the Kolmogorov Entropy of the mappings and studied some applications.

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3

Journal, Baghdad Science. "Classification of Elliptic Cubic Curves Over The Finite Field of Order Nineteen." Baghdad Science Journal 13, no. 4 (December 4, 2016): 846–52. http://dx.doi.org/10.21123/bsj.13.4.846-852.

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Plane cubics curves may be classified up to isomorphism or projective equivalence. In this paper, the inequivalent elliptic cubic curves which are non-singular plane cubic curves have been classified projectively over the finite field of order nineteen, and determined if they are complete or incomplete as arcs of degree three. Also, the maximum size of a complete elliptic curve that can be constructed from each incomplete elliptic curve are given.

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4

Singer, David A. "The Trefoil Soliton." Mathematics 10, no. 9 (May 1, 2022): 1512. http://dx.doi.org/10.3390/math10091512.

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The Kiepert trefoil is an algebraic curve with remarkable geometric and number theoretic properties. Ludwig Kiepert, generalizing ideas due to Serret and Liouville, determined that it could be parametrized by arc length in terms of elliptic functions. In this note, we observe some other properties of the curve. In particular, the curve is a special example of a buckled ring, and thus a solitary wave solution to the planar filament equation, evolving by rotation. It is also a solitary wave solution to a flow in the (three-dimensional) filament hierarchy, evolving by translation.

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5

Bayrakdar, T., and A. A. Ergin. "Motion of an integral curve of a Hamiltonian dynamical system and the evolution equations in 3D." International Journal of Geometric Methods in Modern Physics 14, no. 12 (November 24, 2017): 1750172. http://dx.doi.org/10.1142/s0219887817501729.

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We show that all of the nonstretching curve motions specified in the Frenet–Serret frame in the literature can be described by the time evolution of an integral curve of a Hamiltonian dynamical system such that the underlying curve is a geodesic curve on a leaf of the foliation determined by the Poisson structure in three dimensions. As an illustrative example, we show that the focusing version of the nonlinear Schrödinger equation and the complex modified Korteweg–de Vries (mKdV) equation are obtained in this way.

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Mishra, Amaresh Chandra. "Micromagnetic simulation of hysteresis loop of elliptic permalloy nanorings." International Journal of Modern Physics B 30, no. 26 (October 12, 2016): 1650192. http://dx.doi.org/10.1142/s0217979216501927.

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Magnetic hysteresis behavior of isotropic permalloy elliptic nanorings of outer semi-major axis length [Formula: see text] 100 nm and thickness [Formula: see text] 20 nm were studied with respect to the variation of two parameters: outer semiminor axis length [Formula: see text] and the difference between outer and inner dimensions [Formula: see text]. The outer semiminor axis length [Formula: see text] varied from 90 nm to 20 nm which covers from nearly circular nanoring to elliptic nanoring of high aspect ratio. The value of [Formula: see text] varied in steps of 10 nm. Micromagnetic simulation of in-plane hysteresis curve of these nanorings revealed that the remanent state of all of these elliptic rings are onion states if the magnetic field is applied along the longer side of the elliptic rings. If the magnetic field is applied along the shorter side, then the remanent states turn out to be vortex state. The hysteresis loss indicated by area of the hysteresis loop was found to be decreasing gradually with the increment of either [Formula: see text] or [Formula: see text]. On the other hand, the remanent magnetization increased with increment of [Formula: see text] but decreased with the increment of [Formula: see text]. The changes were attributed to three parameters mainly: inner curvature, exchange energy and demagnetization energy. The changes in loop area were discussed in light of variation of these three parameters.

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Güner, Alper, Alexander Brosius, and A. Erman Tekkaya. "Analysis of the Hydraulic Bulge Test with FEA Concerning the Accuracy of the Determined Flow Curves." Key Engineering Materials 410-411 (March 2009): 439–47. http://dx.doi.org/10.4028/www.scientific.net/kem.410-411.439.

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This work covers the finite element analysis of geometric and process parameters in hydraulic bulge tests in terms of the accuracy of the evaluated flow curve. The important parameters are identified and varied to cover the whole range of possible uses. The effects of these parameters are analyzed for three representative materials: aluminium, mid-strength steel, and high-strength steel. The flow curves of the materials for each set of parameters are calculated by using the results of the simulations and the membrane theory. It is seen that even with simulation results, it is not always possible to obtain the input flow curve, especially towards the end of the test. The dimensions of the sheet and the tooling affect the plastic strain development and geometry of the bulge, leading to errors in computed flow curves. In order to observe the effect of the material flow from the flange on the determined yield stresses, the function and position of the drawbeads are also examined. These parameters, together with the method used to calculate the radius of the bulge, determine the accuracy of the calculated flow curve. Guidelines for an accurate flow curve determination regarding the test set-up and calculation methods are given.

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8

Kohn, Kathlén, and Kristian Ranestad. "Projective Geometry of Wachspress Coordinates." Foundations of Computational Mathematics 20, no. 5 (November 11, 2019): 1135–73. http://dx.doi.org/10.1007/s10208-019-09441-z.

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Abstract We show that there is a unique hypersurface of minimal degree passing through the non-faces of a polytope which is defined by a simple hyperplane arrangement. This generalizes the construction of the adjoint curve of a polygon by Wachspress (A rational finite element basis, Academic Press, New York, 1975). The defining polynomial of our adjoint hypersurface is the adjoint polynomial introduced by Warren (Adv Comput Math 6:97–108, 1996). This is a key ingredient for the definition of Wachspress coordinates, which are barycentric coordinates on an arbitrary convex polytope. The adjoint polynomial also appears both in algebraic statistics, when studying the moments of uniform probability distributions on polytopes, and in intersection theory, when computing Segre classes of monomial schemes. We describe the Wachspress map, the rational map defined by the Wachspress coordinates, and the Wachspress variety, the image of this map. The inverse of the Wachspress map is the projection from the linear span of the image of the adjoint hypersurface. To relate adjoints of polytopes to classical adjoints of divisors in algebraic geometry, we study irreducible hypersurfaces that have the same degree and multiplicity along the non-faces of a polytope as its defining hyperplane arrangement. We list all finitely many combinatorial types of polytopes in dimensions two and three for which such irreducible hypersurfaces exist. In the case of polygons, the general such curves are elliptic. In the three-dimensional case, the general such surfaces are either K3 or elliptic.

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9

Bor, Gil, Mark Levi, Ron Perline, and Sergei Tabachnikov. "Tire Tracks and Integrable Curve Evolution." International Mathematics Research Notices 2020, no. 9 (May 17, 2018): 2698–768. http://dx.doi.org/10.1093/imrn/rny087.

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Abstract We study a simple model of bicycle motion: a segment of fixed length in multi-dimensional Euclidean space, moving so that the velocity of the rear end is always aligned with the segment. If the front track is prescribed, the trajectory of the rear wheel is uniquely determined via a certain first order differential equation—the bicycle equation. The same model, in dimension two, describes another mechanical device, the hatchet planimeter. Here is a sampler of our results. We express the linearized flow of the bicycle equation in terms of the geometry of the rear track; in dimension three, for closed front and rear tracks, this is a version of the Berry phase formula. We show that in all dimensions a sufficiently long bicycle also serves as a planimeter: it measures, approximately, the area bivector defined by the closed front track. We prove that the bicycle equation also describes rolling, without slipping and twisting, of hyperbolic space along Euclidean space. We relate the bicycle problem with two completely integrable systems: the Ablowitz, Kaup, Newell, and Segur (AKNS) system and the vortex filament equation. We show that “bicycle correspondence” of space curves (front tracks sharing a common back track) is a special case of a Darboux transformation associated with the AKNS system. We show that the filament hierarchy, encoded as a single generating equation, describes a three-dimensional bike of imaginary length. We show that a series of examples of “ambiguous” closed bicycle curves (front tracks admitting self bicycle correspondence), found recently F. Wegner, are buckled rings, or solitons of the planar filament equation. As a case study, we give a detailed analysis of such curves, arising from bicycle correspondence with multiply traversed circles.

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10

Jin, Rong, Bing Fei Gu, and Guo Lian Liu. "Research on Generation Rules of Chest Width Point Curve Based on 3D Female Mannequin." Advanced Materials Research 796 (September 2013): 513–18. http://dx.doi.org/10.4028/www.scientific.net/amr.796.513.

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In this paper 110 female undergraduates in Soochow University are measured by using 3D non-contact measurement system and manual measurement. 3D point cloud data of human body is taken as research objects by using anti-engineering software, and secondary development of point cloud data is done on the basis of optimizing point cloud data. In accordance with the definition of the human chest width points and other feature points, and in the operability of the three-dimensional point cloud data, the width, thickness, and length dimensions of the curve through the chest width point are measured. Classification of body type is done by choosing the ratio values as classification index which is the ratio between thickness and width of the curve. The generation rules of the chest curve are determined for each type by using linear regression method. Human arm model could be established by the computer automatically. Thereby the individual model of the female upper body mannequin modeling can be improved effectively.

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11

AREF, HASSAN, and MORTEN BRØNS. "On stagnation points and streamline topology in vortex flows." Journal of Fluid Mechanics 370 (September 10, 1998): 1–27. http://dx.doi.org/10.1017/s0022112098001761.

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The problem of locating stagnation points in the flow produced by a system of N interacting point vortices in two dimensions is considered. The general solution follows from an 1864 theorem by Siebeck, that the stagnation points are the foci of a certain plane curve of class N−1 that has all lines connecting vortices pairwise as tangents. The case N=3, for which Siebeck's curve is a conic, is considered in some detail. It is shown that the classification of the type of conic coincides with the known classification of regimes of motion for the three vortices. A similarity result for the triangular coordinates of the stagnation point in a flow produced by three vortices with sum of strengths zero is found. Using topological arguments the distinct streamline patterns for flow about three vortices are also determined. Partial results are given for two special sets of vortex strengths on the changes between these patterns as the motion evolves. The analysis requires a number of unfamiliar mathematical tools which are explained.

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12

Müller, J. J., and H. Schrauber. "The inertia-equivalent ellipsoid: a link between atomic structure and low-resolution models of small globular proteins determined by small-angle X-ray scattering." Journal of Applied Crystallography 25, no. 2 (April 1, 1992): 181–91. http://dx.doi.org/10.1107/s0021889891011421.

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Low-resolution three-parameter models of the shape of a biopolymer in solution can be determined by a new indirect method from small-angle X-ray scattering without contrast-variation experiments. The basic low-resolution model employed is a triaxial ellipsoid – the inertia-equivalent ellipsoid (IEE). The IEE is related to the tensor of inertia of a body and the eigenvalues and eigenvectors of this tensor can be calculated directly from the atomic coordinates and from the homogeneous solvent-excluded body of a molecule. The IEE defines a mean molecular surface (like the sea level on earth) which models the molecular shape adequately if the IEE volume is not more than 30% larger than the dry volume of the molecule. Approximately 10 to 15% of the solvent-excluded volume is outside the ellipsoid; the radii of gyration of the IEE and of the homogeneous molecular body are identical. The largest diameter of the IEE is about 5 to 15% (~0.2–0.8 nm) smaller than the maximum dimension of globular molecules with molecular masses smaller than 65000 daltons. From the scattering curve of a molecule in solution the IEE can be determined by a calibration procedure. 29 proteins of known crystal structure have been used as a random sample. Systematic differences between the axes of the IEE, calculated directly from the structure, and the axes of the scattering-equivalent ellipsoids of revolution, estimated from the scattering curve of the molecule in solution, are used to derive correction factors for the axial dimensions. Distortions of model dimensions of 20 to 40% (up to 1 nm), caused by misinterpretation of scattering contributions from electron density fluctuations within the molecule, are reduced to a quarter by applying these correction factors to the axes of the scattering-equivalent ellipsoids of revolution. In a computer experiment the axes of the inertia-equivalent ellipsoids have been determined for a further nine proteins with the same accuracy. The automated estimation of the IEE from the scattering curve of a molecule in solution is realized by the Fortran77 program AUTOIEE.

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13

& Al-Masoudi, Al-Dobaissi. "STUDY OF FRUITS MORPHOLOGICAL FEATURES FOR 33 SPECIES BELONG TO CRUCIFERAE FAMILY IN IRAQ." IRAQI JOURNAL OF AGRICULTURAL SCIENCES 52, no. 4 (August 22, 2021): 1039–49. http://dx.doi.org/10.36103/ijas.v52i4.1415.

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The research was aimed to identify fruits morphological characteristics of 33 taxa belonging to the Lepidieae tribe from Brassicaceae. The characteristics of the fruit's general shape, apex shape, dimensions, colors, surface ornamentation, and beak were determined, the results indicated the importance of each of those characters in isolated species, In general, all the tribe's fruits were open capsule and short silicula. According to the dimensions of fruit, three species can be distinguished as a group with dimensions greater than 20mm, as in Brossardia, Coluteocarpus, and Didymophysa, and depending on the shape, it was possible to differentiate the species within this group, while the other species were less than 20 mm. in dimensions. They were distinguished by the general shapes, as the fruits of the Aethionema species were distinguished by their winged shaped, whereas the fruits of the genus Biscutella are bi-lobed, and the fruits have an inverted semi-triangular shape in the Capsella and peltate with prominent veins in the genus Horwoodia, or maybe peltate and longitudinally splintered with dark veins in Iberis, while the genus Sameraria fruit is circular to semi-circular characterized by intermediate appendages, while the individuals of the genus Isatis have linear-oblong fruits, and the species of both genus Lipidium and Hymenolobus were distinguished by their small and elliptic fruits and could be differentiated according to other fruits features. So could be conclude the importance of the characteristic of the general shape of the fruit firstly in species isolation then size, ornamentation, and some other traits.

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Pasangka, Bartholomeus, and Frederika Rambu Ngana. "RADIATION MEASUREMENT OF RADIOISOTOPE IN MINERAL DEPOSIT AT SUBDISTRICT OF MIDDLE KUPANG WEST TIMOR ISLAND INDONESIA." Jurnal Fisika : Fisika Sains dan Aplikasinya 5, no. 1 (April 15, 2020): 78–86. http://dx.doi.org/10.35508/fisa.v5i1.2388.

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The general objective of this work was investigation of radioisotope distribution and accumulation center in mineral deposit at sub-district of Middle Kupang West Timor Island Indonesia. The purposes of research were: to map of radioisotope distribution in the mineral deposit, to estimate area of radioisotope accumulation center in the mineral deposit, to establish range of nuclear radiation counts in the center region of radioisotope content in mineral deposit. The general methods used in this research were observation, survey, mapping, analysis, and interpretation. Procedures detail of research consists of: observe and identify the potential region and plot gridding, calibrate equipment necessary, measure background count in around of survey location and nuclear radiation in the survey location, plot of three dimensions curve and contour after corrected by background count. Based on geology information or geology data (drilling data) three depth levels determined (about 20 m, 40 m and 60 m), Radiation powers were calculated for estimation of accumulation center of radioisotope in deposit mineral, and contour and three dimensions curves of radiation power of radioisotope in deposit mineral were plotted. Results: Based on three dimensional curves and contour map (radiation counts and radiation powers on three levels) of radioisotope in mineral deposit respectively was distributed on area 3.00 x 106 m2, and 1.56 x 104 m2. The interval of radiation counts of radioisotope in mineral deposit was 10 counts per minute-137 counts per minute. Keywords: Radiation, measurement, radioisotope, mineral, deposit

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Letchov, George, Venelin Roychev, and Neli Keranova. "Metrics for studying berry growth kinetics in seedless grape cultivars (Vitis vinifera L.)." OENO One 55, no. 1 (February 3, 2021): 119–31. http://dx.doi.org/10.20870/oeno-one.2021.55.1.4476.

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The process related to the changes in dimensions and mass of grape berry passes through two growth phases separated by a lag phase, and can be described by a double sigmoid curve. The onset of the growth phases and their duration are important factors for understanding the growth processes in grape berries. A new method for their quantitative determination was developed in the present study. In this method, the phase transition dates correspond to the times at which the rate of change of the curvature of the logistic (sigmoid) curve reaches an extreme value. The method was tested on three seedless grape varieties, Sultanina, Ruby Seedless and Rusalka 3, and the changes in grape berry dimensions and mass were tracked from anthesis to harvest. For each of the varieties, a double logistic model of change in berry length, width and mass from anthesis to harvest was developed and the metrics of growth - beginning, stabilisation and end of growth - for each of the two phases were determined. It was found that the metrics in mass and berry dimensions do not match and shift relative to each other over time. A comparison of growth metrics with phenological metrics, such as anthesis, veraison and ripening, showed that phenophases cannot be used as a time scale to record the acceleration of growth processes, as they shifted in time with growth metrics. An exception was veraison, which coincided with the beginning of the accelerated growth of grapes during the second growth phase, following the lag phase. The time scale presented in the current research is a new tool for monitoring growth processes and could help clarify the links between visible changes in the grape berries and the ongoing processes within them. The developed method can also be used for the analysis of various growth processes that follow the logistic law.

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16

James, I. J., and O. A. Osinowo. "Relationship between udder measurements during pregnancy and partial daily milk yield in goats." Nigerian Journal of Animal Production 31, no. 2 (January 7, 2021): 252–62. http://dx.doi.org/10.51791/njap.v31i2.1822.

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Relationship between udder measurements during pregnancy and partial daily milk yield (PDM) in ten West African Dwarf (WAD), three Red Sokoto (RS) and Sahel goats was studied. Udder width (UW), udder circumference (UC), distance between teats (DBT) and teat length (TL) were measured monthly before conception and during pregnancy up to parturition. PDM was determined weekly for 12 weeks of lactation commencing from 4 days post partum. There was a slight increase in udder dimensions within the first 2 trimesters of pregnancy (day 0 - 100) and then followed by an exponential increase during the third trimester (last 50 days of pregnancy) across the breeds. Sahel does had the largest udder dimensions with highest average PDM while WAD does had the smallest udder with lowest average PDM. The highest correlations between udder growth curve parameters and average PDM were obtained with A (r. 0.795) and b (r = 0.609). Thus, udder size at conception and during pregnancy appeared to be a significant determinant of average PDM per lactation and could be more important to average PDM than the rate of increase in udder size during pregnancy.

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17

Reme, Silje Endresen, and Hege R. Eriksen. "Is one question enough to screen for depression?" Scandinavian Journal of Public Health 38, no. 6 (July 5, 2010): 618–24. http://dx.doi.org/10.1177/1403494810376559.

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Aims: The aim of this study was to determine if chronic pain patients with symptoms of depression could be identified by one single question. Methods: Data from 595 patients, 55% women, and 45% men, from three different patient populations; low back pain patients (n = 387), whiplash patients (n = 119), and disability pensioners (n = 89), were analysed. We evaluated the test characteristics of one question on depression from the Subjective Health Complaints (SHC) Inventory. The respondents report if, and to what extent, they have been affected by sadness/depression in the last 30 days. The Hopkins Symptom Checklist-25 (HSCL-25) was used as the criterion standard. HSCL-25 is a self-report symptom rating scale with two dimensions: depression and anxiety. ‘‘Depressed’’ was defined as having a score above 1.75 on the depression subscale. Results: Thirty-three per cent of the patients were depressed according to HSCL-25. The sensitivity of the single SHC depression-question was 79%, and the specificity was 81%. Positive predictive value was 67% while negative predictive value was 89%. Kappa value for all groups combined was 0.58 (p < 0.001). The receiver operating characteristic (ROC) curve showed an area under the curve of 0.83. Conclusions: The depression-question from SHC identified most of the depressed patients measured by HSCL-25 in low back pain patients, whiplash patients, and disability pensioners, and can therefore be considered an indicator of depression. Satisfactory sensitivity and specificity were detected, as well as similar responsiveness as determined by the ROC analyses. The results indicate that one simple question could replace a whole questionnaire (HSCL-25) in identifying depressive patients.

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Szymkiewicz, Adam, Jolanta Lewandowska, Rafael Angulo-Jaramillo, and Joanna Butlańska. "Two-scale modeling of unsaturated water flow in a double-porosity medium under axisymmetric conditions." Canadian Geotechnical Journal 45, no. 2 (February 2008): 238–51. http://dx.doi.org/10.1139/t07-096.

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In this paper the development and experimental validation of a numerical model of two-dimensional unsaturated flow in a double-porosity medium is presented. The model is based on the coupled formulation for flow in macro- and micropores obtained by homogenization. It was applied to simulate the axisymmetrical tension disk infiltration experiments that were carried out in a double-porosity medium. The physical model was a three-dimensional periodic structure, composed of porous spheres made of sintered clay and embedded in Hostun fine sand HN38. The hydraulic parameters of both porous materials were determined by inverse analysis of independent infiltration experiments performed on sand and sintered clay. The effective parameters of the double-porosity medium were calculated from the solution of the local boundary value problem, obtained from the homogenization procedure. The cumulative infiltration curve and the global dimensions of the humidified zone obtained from the numerical solution are in good agreement with the observations. Moreover, numerical simulations showed the existence of a narrow zone of local nonequilibrium that moves with the infiltration front. Upstream of this zone, the infiltration bulb is in the local equilibrium conditions.

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Frantík, Petr, Pavla Rovnaníková, and Zbyněk Keršner. "Strength of AAAS Composites with Ceramic Precursor over Time." Solid State Phenomena 322 (August 9, 2021): 60–65. http://dx.doi.org/10.4028/www.scientific.net/ssp.322.60.

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The paper deals with the approximation of the time evolution of the strengths of selected alkali-activated aluminosilicate (AAAS) composites based on ceramic precursors. Composites made of brick dust as a precursor and an alkaline activator with a silicate modulus of Ms = 0.8, 1.0, 1.2, 1.4, and 1.6 were investigated. The filler consisted of standard quartz sand in one case, and crushed brick in the other. The test specimens had nominal dimensions of 40 × 40 × 160 mm and were tested in three-point bending after 7, 28, 90, and 300 days of maturation. From each composite, 3 specimens were tested and the compressive strength was determined from the 6 specimen parts that remained after the bending tests. The obtained flexural and compressive strength values for the abovementioned 4 composite ages were approximated by the exponential function , where the coefficient a represents a horizontal asymptote to the approximation curve, i.e. the theoretical strength of the composite at time t = ∞; the exponential term of the approximation with the coefficients b and c expresses the degree of the time-dependent change of the respective compressive strength in the interval t = (0, ∞). The approximation was performed with the least squares method using genetic algorithms implemented in the Java GA package with open source code.

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Schwartze, Manuel M., Anne C. Frenzel, Thomas Goetz, Reinhard Pekrun, Corinna Reck, Anton K. G. Marx, and Daniel Fiedler. "Boredom Makes Me Sick: Adolescents’ Boredom Trajectories and Their Health-Related Quality of Life." International Journal of Environmental Research and Public Health 18, no. 12 (June 10, 2021): 6308. http://dx.doi.org/10.3390/ijerph18126308.

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Existing research shows consistent links between boredom and depression, somatic complaints, substance abuse, or obesity and eating disorders. However, comparatively little is known about potential psychological and physical health-related correlates of academic boredom. Evidence for such a relationship can be derived from the literature, as boredom has adverse consequences in both work and achievement-related settings. The present study investigates latent correlations of 1.484 adolescents’ (Mage = 13.23) mathematics boredom scores at three time points during a semester in 2018/19 and their Rasch scaled health-related quality of life (HRQoL). Moreover, we applied latent growth curve modeling to estimate boredom trajectories across the semester and determined the relationship between the latent growth parameters of student boredom and HRQoL in bivariate correlation analyses. Our results show that boredom is significantly negatively linked with all HRQoL dimensions (physical well-being, psychological well-being, autonomy and parent relation, social support and peers, school environment [SCH], and general HRQoL [GH]). Furthermore, stronger increases in boredom across the semester were negatively associated with SCH scores and GH. In conclusion, given that boredom is negatively linked with HRQoL and that stronger boredom growth is linked with more severe health-related problems, signs of academic boredom could be an early warning signal for adolescents’ potentially severe problems.

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Singh, Pankaj Kumar, Raj Kumar Karki, Abdul Sami Khan, Dhiraj Kumar Shah, and Sushant Bhardwaj. "Assessment of Sexual Dimorphism from the Mastoid Triangle Using 3d CT scan in Nepalese Population." Birat Journal of Health Sciences 6, no. 2 (November 3, 2021): 1486–91. http://dx.doi.org/10.3126/bjhs.v6i2.40330.

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Introduction: Skull plays an important role, second only next to pelvis for sex determination. In skull, mastoid and occipital region due to its anatomical location is the most protected region, offering high resistance to decomposition and any form of tempering. With the intension of studying sexual dimorphism in the mastoid region involving mastoid process, we initiated this study. The technique we adopted was first introduced by Paiva and Segre, i.e. measuring the distance between three cranio-metric land mark (Porion, Mastoidale, and Asterion) and calculating the area of the triangle to study sexual dimorphism. Objective: The objective of this study is to determine sex based on mastoid triangle dimensions measured in 3D reconstructed computed tomography of the skull. Methodology: The study included 196, 3D reconstructed CT scan images of skull, 98 of which were males and 98 of which were females. The three craniometric points were marked to demarcate the mastoid triangle on both side (mention the software used).Heron’s formula was used for measurement of mastoid triangle areas. Result: Descriptive statistics and the student t-test revealed that males have larger mastoid triangle dimensions in all measurements than females, with a significant difference (p<0.000) between them. The paired t-test revealed no statistically significant difference (p<0.05) between the right and left sides. Apart from angle asterion (p<0.05) on the right side, no other mastoid triangle angles on either side showed a significant difference. The predictability of mastoid triangle measurements and areas was determined using a discriminant function and ROC curve analysis. The calculated mastoid triangle measurements and areas were 72.5 % of Asterion to Porion, 74.5 % of Asterion to Mastoidale, 86.3 % of Mastoidale to Porion, and 88.2 % of areas, respectively. Conclusion: The study findings suggest that mastoid triangle could be used to determine gender in the case of fragmentary skull remains by the forensic experts in the course of investigation. In order to generalize the data nationally, an autopsy-based, large sample size study on different age groups should be conducted.

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de la Rosa, Ángel, Gonzalo Ruiz, and Elisa Poveda. "Study of the Compression Behavior of Steel-Fiber Reinforced Concrete by Means of the Response Surface Methodology." Applied Sciences 9, no. 24 (December 6, 2019): 5330. http://dx.doi.org/10.3390/app9245330.

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The compression behavior of steel-fiber reinforced concrete (SFRC) has been addressed exhaustively in recent decades thereby highlighting a variety of differences with regard to the effect that the addition of fiber has on it. In this paper, a detailed study of the subject is developed for which a database has been created, which includes 197 tests performed on cylindrical concrete specimens with dimensions of 150 × 300 mm 2 (diameter × height). By means of the response surface methodology, we disclose the relationship that exists between the geometric parameters of the fiber (length, diameter, and aspect ratio), their amount (fraction in volume), and some matrix parameters (compression resistance and maximum size of coarse aggregate) with the different compression responses of the SFRC, which are strength, elastic modulus, critical deformation under maximum load, and the volumetric deformation work in the pre- and post-peak branch. Linear polynomial models are chosen to adjust each response with the defined factors, and said variables are studied in a dimensional and non-dimensional format. From the results obtained, it is verified how the inclusion of steel-fibers produces notable improvements in ductility and the energy absorption capacity of the concrete when significantly increasing the works of volumetric deformation in the pre- and post-peak branch with respect to the matrix without fibers. In addition, a new model is analyzed, which describes the stress–strain curve of the compression behavior of the SFRC based on the increase of ductility and energy absorption. This model is characterized by a softening branch subsequent to the peak load determined by means of the residual compressive strength, a parameter that corresponds to the value of the compressive stress associated with a strain equal to three times that of the peak of the curve, which is significantly dependent on the aspect ratio and fiber content.

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Seth, Siddhartha, and Norman R. Morrow. "Efficiency of the Conversion of Work of Drainage to Surface Energy for Sandstone and Carbonate." SPE Reservoir Evaluation & Engineering 10, no. 04 (August 1, 2007): 338–47. http://dx.doi.org/10.2118/102490-pa.

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Summary The increase in surface energy resulting from drainage of a wetting phase from a porous medium is often equated to the work of displacement determined from the area under its capillary pressure curve. However, capillary pressure vs. saturation relationships are not reversible and do not represent quasistatic displacement. The increase in surface energy is less than the work done because of inherent capillary instabilities that are the basic cause of capillary pressure hysteresis. Nevertheless, relating the area under a capillary pressure curve to the thermodynamic work of displacement can be justified by interpreting the curve as a series of alternating isons (reversible displacements) and rheons (spontaneous redistribution at constant saturation). The efficiency of conversion of work to surface energy, Ed, depends on the increase in surface area that accompanies drainage. Surface areas of nonwetting phase/solid and nonwetting phase/wetting phase have been determined through displacement of a colored low-viscosity liquid resin that can be solidified so that thin sections reveal the distribution of phases and surfaces within the pore space of the rock. Two-dimensional images obtained from thin sections were analyzed using stereology to obtain estimates of saturations and interfacial areas in three dimensions. For drainage of Berea sandstone to 20% wetting-phase saturation, Ed was 36%, which was less than one-half of the efficiency of 85% for the same range of change in saturation determined previously for random packings of equal spheres. Values of Ed for the tested carbonate were approximately one-half of those for sandstone. The wide variation is explained in terms of a simple pore model that relates Ed to aspect ratio. Introduction Changes in fluid saturations during multiphase displacements in porous media are accompanied by changes in interfacial surface area between the phases. Interfacial areas are directly related to surface energy and are fundamental to spontaneous-imbibition phenomena, to multiphase transport properties such as relative permeability, and to processes that involve mass transfer between phases (Haines 1930; Leverett 1941; Rapoport and Leas 1951; Payne 1953; Rootare and Prenzlow 1967; Hassanizadeh and Gray 1993; Reeves and Celia 1996; Kim et al. 1997; Alpak et al. 1999; Schaefer et al. 2000a, 2000b; Beliaev and Hassanizadeh 2001; Wan and Tokunaga 2002; Jain et al. 2003; Cheng et al. 2004). The relationship between work of displacement from capillary pressure data to changes in surface energy from direct measurements of surface areas has been reported in detail for drainage, imbibition, and secondary drainage for random packings of equal spheres (Morrow 1970a). The first measurements of relationships between work and increase in surface energy for porous rocks are reported here for primary drainage of a sandstone and a limestone.

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Mittal, Sanjay, Varun Bhatt, and D. N. Srinath. "Aerodynamic shape optimization using stabilized finite element method." Mathematical Models and Methods in Applied Sciences 25, no. 12 (August 24, 2015): 2319–48. http://dx.doi.org/10.1142/s0218202515400102.

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An algorithm for aerodynamic shape optimization using a gradient-based approach is presented. A stabilized finite element method is utilized to solve the equations governing the fluid flow and adjoint variables. The effectiveness of the method in finding nontrivial designs that satisfy the posed objectives and constraints is demonstrated. It is shown that the initial guess plays an important role in the optimal solution that is realized. Shapes of bumps that are associated with a specified volume, lift and drag are determined and presented. The method is applied to design of airfoils in unsteady flows. The objective function is based on time-averaged force coefficients. The effect of enriching the design space is studied. It is shown that this being a local method, where the search direction is based on gradient of the objective function, the gradual enrichment of design space leads to superior performance. The idea is demonstrated via spontaneous appearance of corrugations on an airfoil surface during the optimization, for maximum lift, by gradually increasing the number of control points. The method is extended to three dimensions. Its application is demonstrated via optimization of the planform of a finite wing for maximum lift-to-drag ratio. A bi-parametric tensorial NURBS (non-uniform rational bi-cubic spline) surface is interpolated on a 3D control net to represent a wing surface. It is shown that for low Reynolds number, it is possible to design a planform that is more efficient than an ellipse. Unlike the elliptic planform, the optimal wing computed by the present method, is associated with a short winglet-like structure at the wing-tip and the maximum chord length at around mid-span.

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Groth, Eduardo Becker, Thomas Gabriel Rosauro Clarke, Guilherme Schumacher da Silva, Ignacio Iturrioz, and Giuseppe Lacidogna. "The Elastic Wave Propagation in Rectangular Waveguide Structure: Determination of Dispersion Curves and Their Application in Nondestructive Techniques." Applied Sciences 10, no. 12 (June 26, 2020): 4401. http://dx.doi.org/10.3390/app10124401.

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The use of mechanic waves for assessing structural integrity is a well-known non-destructive technique (NDT). The ultrasound applied in the guided wave in particular requires significant effort in order to understand the complexities of the propagation so as to develop new methods in damage detection, in this case, knowing the interaction between the wave propagation and the geometry of the waveguides is mandatory. In the present work, the wave propagation in rectangular steel rod is presented. In this study, the section dimensions were fixed as 5 × 15 [mm], a typical element of the flexible riser structural amour commonly used in the offshore oil industry. The studies here presented were restricted to [0, 100 KHz] frequencies. This frequency interval is in the range of commercial waveguide equipment commonly applied in ducts in NDT applications. The computation of the dispersion curves is performed by using three different methodologies: (i) analytical solutions, (ii) a method that combines analytical approaches with finite element methods (SAFE), and (iii) experimental method that extracted information from the rod using laser vibrometers and piezoelectric actuators. Finally, two applications based on the dispersion curves determined in the rectangular waveguide are presented to illustrate the possibilities of the curve dispersion knowledge related to the specific geometry in the development and application linked to NDT. The first application consists on showing the possibilities of the techniques that use a fiber grating Bragg cell (FGB) to measure the wave displacement and the second application involves the simulation of pre-fissured prismatic waveguide aimed at searching to induce three characteristic acoustic events. The model was built combining the finite element method and a version of the discrete element method.

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Carmona-Pérez, Cristina, Alberto Pérez-Ruiz, Juan L. Garrido-Castro, Francisco Torres Vidal, Sandra Alcaraz-Clariana, Lourdes García-Luque, Daiana Priscila Rodrigues-de-Souza, and Francisco Alburquerque-Sendín. "Design, Validity, and Reliability of a New Test, Based on an Inertial Measurement Unit System, for Measuring Cervical Posture and Motor Control in Children with Cerebral Palsy." Diagnostics 10, no. 9 (September 1, 2020): 661. http://dx.doi.org/10.3390/diagnostics10090661.

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Objective: The aim of this study was to design and propose a new test based on inertial measurement unit (IMU) technology, for measuring cervical posture and motor control in children with cerebral palsy (CP) and to evaluate its validity and reliability. Methods: Twenty-four individuals with CP (4–14 years) and 24 gender- and age-matched controls were evaluated with a new test based on IMU technology to identify and measure any movement in the three spatial planes while the individual is seated watching a two-minute video. An ellipse was obtained encompassing 95% of the flexion/extension and rotation movements in the sagittal and transversal planes. The protocol was repeated on two occasions separated by 3 to 5 days. Construct and concurrent validity were assessed by determining the discriminant capacity of the new test and by identifying associations between functional measures and the new test outcomes. Relative reliability was determined using the intraclass correlation coefficient (ICC) for test–retest data. Absolute reliability was obtained by the standard error of measurement (SEM) and the Minimum Detectable Change at a 90% confidence level (MDC90). Results: The discriminant capacity of the area and both dimensions of the new test was high (Area Under the Curve ≈ 0.8), and consistent multiple regression models were identified to explain functional measures with new test results and sociodemographic data. A consistent trend of ICCs higher than 0.8 was identified for CP individuals. Finally, the SEM can be considered low in both groups, although the high variability among individuals determined some high MDC90 values, mainly in the CP group. Conclusions: The new test, based on IMU data, is valid and reliable for evaluating posture and motor control in children with CP.

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Koch, K., and M. Schmidt. "N-dimensional B-spline surface estimated by lofting for locally improving IRI." Journal of Geodetic Science 1, no. 1 (March 1, 2011): 41–51. http://dx.doi.org/10.2478/v10156-010-0006-3.

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N-dimensional B-spline surface estimated by lofting for locally improving IRIN-dimensional surfaces are defined by the tensor product of B-spline basis functions. To estimate the unknown control points of these B-spline surfaces, the lofting method also called skinning method by cross-sectional curve fits is applied. It is shown by an analytical proof and numerically confirmed by the example of a four-dimensional surface that the results of the lofting method agree with the ones of the simultaneous estimation of the unknown control points. The numerical complexity for estimating vn control points by the lofting method is O(vn+1) while it results in O(v3n) for the simultaneous estimation. It is also shown that a B-spline surface estimated by a simultaneous estimation can be extended to higher dimensions by the lofting method, thus saving computer time.An application of this method is the local improvement of the International Reference Ionosphere (IRI), e.g. by the slant total electron content (STEC) obtained by dual-frequency observations of the Global Navigation Satellite System (GNSS). Three-dimensional B-spline surfaces at different time epochs have to be determined by the simultaneous estimation of the control points for this improvement. A four-dimensional representation in space and time of the electron density of the ionosphere is desirable. It can be obtained by the lofting method. This takes less computer time than determining the four-dimensional surface solely by a simultaneous estimation.

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Kupe, Muhammed, Bahadır Sayinci, Bünyamin Demir, Sezai Ercisli, Kürşat Alp Aslan, Muhammet Ali Gundesli, Mojmir Baron, and Jiri Sochor. "Multivariate Analysis Approaches for Dimension and Shape Discrimination of Vitis vinifera Varieties." Plants 10, no. 8 (July 26, 2021): 1528. http://dx.doi.org/10.3390/plants10081528.

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In this study, berry dimensions and shape traits, which are important for the design of the grape processing system and the classification of 10 different grape varieties grown in same ecological conditions (‘Ata Sarısı’, ‘Barış’, ‘Dımışkı’, ‘Hatun Parmağı’, ‘Helvani’, ‘Horoz Karası’, ‘Hönüsü’, ‘İtalia’, ‘Mevlana Sarısı’, and ‘Red Globe’) were determined; differences between the varieties were identified with the use of discriminant analysis. The largest grape varieties were identified as ‘Ata Sarısı’ and ‘Red Globe’. The ‘Red Globe’ and ‘Helvani’ varieties had geometrically sphere-like shape. The ‘Barış’ variety had the lowest size averages. According to elliptic Fourier analysis, the primary source of shape variation was ellipse and sphere-looking varieties. However, shape variation was seen due to the existence of a small number of drop-like varieties. According to discriminant analysis, shape differences of the varieties were defined by two discriminant functions. Based on these discriminant functions, the greatest classification performance was achieved for ‘Mevlana Sarısı’ and ‘Dımışkı’. In scatter plots, three shape definitions (sphere, ellipse, and drop) were made for grape varieties. Cluster analysis revealed 4 sub-groups. The first sub-group included the ‘Mevlana Sarısı’ variety; the second sub-group included the ‘Hönüsü’, ‘Hatun Parmağı’, ‘Dımışkı’, and ‘Horoz Karası’ varieties; the third sub-group included the ‘Ata Sarısı’ variety; the fourth sub-group included the ‘Barış’, ‘Helvani’, ‘İtalia’, and ‘Red Globe’ varieties. The variety in the first group had a geometrically ellipse-like shape, the largest length, and the smallest width. The size data were the smallest for the second sub-group. The third sub-group, with the ellipse-like shape, had the large size data. The grape varieties the closest to the sphere were classified in the fourth group, and these varieties had the large sizes.

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STEWART, B. E., M. C. THOMPSON, T. LEWEKE, and K. HOURIGAN. "The wake behind a cylinder rolling on a wall at varying rotation rates." Journal of Fluid Mechanics 648 (April 7, 2010): 225–56. http://dx.doi.org/10.1017/s0022112009993053.

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A study investigating the flow around a cylinder rolling or sliding on a wall has been undertaken in two and three dimensions. The cylinder motion is specified from a set of five discrete rotation rates, ranging from prograde through to retrograde rolling. A Reynolds number range of 20–500 is considered. The effects of the nearby wall and the imposed body motion on the wake structure and dominant wake transitions have been determined. Prograde rolling is shown to destabilize the wake flow, while retrograde rotation delays the onset of unsteady flow to Reynolds numbers well above those observed for a cylinder in an unbounded flow.Two-dimensional simulations show the presence of two recirculation zones in the steady wake, the lengths of which increase approximately linearly with the Reynolds number. Values of the lift and drag coefficient are also reported for the steady flow regime. Results from a linear stability analysis show that the wake initially undergoes a regular bifurcation from a steady two-dimensional flow to a steady three-dimensional wake for all rotation rates. The critical Reynolds number Rec of transition and the spanwise wavelength of the dominant mode are shown to be highly dependent on, but smoothly varying with, the rotation rate of the cylinder. Varying the rotation from prograde to retrograde rolling acts to increase the value of Rec and decrease the preferred wavelength. The structure of the fully evolved wake mode is then established through three-dimensional simulations. In fact it is found that at Reynolds numbers only marginally (~5%) above critical, the three-dimensional simulations indicate that the saturated state becomes time dependent, although at least initially, this does not result in a significant change to the mode structure. It is only at higher Reynolds numbers that the wake undergoes a transition to vortex shedding.An analysis of the three-dimensional transition indicates that it is unlikely to be due to a centrifugal instability despite the superficial similarity to the flow over a backward-facing step, for which the transition mechanism has been speculated to be centrifugal. However, the attached elongated recirculation region and distribution of the spanwise perturbation vorticity field, and the similarity of these features with those of the flow through a partially blocked channel, suggest the possibility that the mechanism is elliptic in nature. Some analysis which supports this conjecture is undertaken.

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Prasad, Rahul R., and K. R. Sreenivasan. "Quantitative three-dimensional imaging and the structure of passive scalar fields in fully turbulent flows." Journal of Fluid Mechanics 216 (July 1990): 1–34. http://dx.doi.org/10.1017/s0022112090000325.

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The three-dimensional turbulent field of a passive scalar has been mapped quantitatively by obtaining, effectively instantaneously, several closely spaced parallel two-dimensional images; the two-dimensional images themselves have been obtained by laser-induced fluorescence. Turbulent jets and wakes at moderate Reynolds numbers are used as examples. The working fluid is water. The spatial resolution of the measurements is about four Kolmogorov scales. The first contribution of this work concerns the three-dimensional nature of the boundary of the scalar-marked regions (the ‘scalar interface’). It is concluded that interface regions detached from the main body are exceptional occurrences (if at all), and that in spite of the large structure, the randomness associated with small-scale convolutions of the interface are strong enough that any two intersections of it by parallel planes are essentially uncorrelated even if the separation distances are no more than a few Kolmogorov scales. The fractal dimension of the interface is determined directly by box-counting in three dimensions, and the value of 2.35 ± 0.04 is shown to be in good agreement with that previously inferred from two-dimensional sections. This justifies the use of the method of intersections. The second contribution involves the joint statistics of the scalar field and the quantity χ* (or its components), χ* being the appropriate approximation to the scalar ‘dissipation’ field in the inertial–convective range of scales. The third aspect relates to the multifractal scaling properties of the spatial intermittency of χ*; since all three components of χ* have been obtained effectively simultaneously, inferences concerning the scaling properties of the individual components and their sum have been possible. The usefulness of the multifractal approach for describing highly intermittent distributions of χ* and its components is explored by measuring the so-called singularity spectrum (or the f(α)-curve) which quantifies the spatial distribution of various strengths of χ*. Also obtained is a time sequence of two-dimensional images with the temporal resolution on the order of a few Batchelor timescales; this enables us to infer features of temporal intermittency in turbulent flows, and qualitatively the propagation speeds of the scalar interface. Finally, a few issues relating to the resolution effects have been addressed briefly by making point measurements with the spatial and temporal resolutions comparable with the Batchelor lengthscale and the corresponding timescale.

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Javaheri, Ehsan, Verdiana Kumala, Alireza Javaheri, Reza Rawassizadeh, Janot Lubritz, Benjamin Graf, and Michael Rethmeier. "Quantifying Mechanical Properties of Automotive Steels with Deep Learning Based Computer Vision Algorithms." Metals 10, no. 2 (January 22, 2020): 163. http://dx.doi.org/10.3390/met10020163.

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This paper demonstrates that the instrumented indentation test (IIT), together with a trained artificial neural network (ANN), has the capability to characterize the mechanical properties of the local parts of a welded steel structure such as a weld nugget or heat affected zone. Aside from force-indentation depth curves generated from the IIT, the profile of the indented surface deformed after the indentation test also has a strong correlation with the materials’ plastic behavior. The profile of the indented surface was used as the training dataset to design an ANN to determine the material parameters of the welded zones. The deformation of the indented surface in three dimensions shown in images were analyzed with the computer vision algorithms and the obtained data were employed to train the ANN for the characterization of the mechanical properties. Moreover, this method was applied to the images taken with a simple light microscope from the surface of a specimen. Therefore, it is possible to quantify the mechanical properties of the automotive steels with the four independent methods: (1) force-indentation depth curve; (2) profile of the indented surface; (3) analyzing of the 3D-measurement image; and (4) evaluation of the images taken by a simple light microscope. The results show that there is a very good agreement between the material parameters obtained from the trained ANN and the experimental uniaxial tensile test. The results present that the mechanical properties of an unknown steel can be determined by only analyzing the images taken from its surface after pushing a simple indenter into its surface.

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DuttaRoy, Rahul, SR Chakravarthy, and Ashis Kumar Sen. "Experimental investigation of flame propagation in a meso-combustor." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 234, no. 8 (December 31, 2019): 1131–46. http://dx.doi.org/10.1177/0957650919897755.

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The present work aims to study the quenching of propagating flames in meso-combustors for which dimensions are of the order of quenching distances of hydrocarbon fuels. Combustion of gaseous fuels and subsequent flame propagation in a meso-scale combustor duct of square cross-section is studied experimentally. Premixed mixtures of methane, propane, and ethylene with air are considered. Two different variants of flame propagation states are found to occur in the meso-combustor, viz., one undergoing flame propagation till the combustor entry and quenching at the step and the other undergoing wall quenching. Regime transitions across these flame states are mapped comprehensively over a wide range of operating conditions. The radius of curvature of the flame and the dead space between the flame and the wall are determined for those conditions with the aid of curve fitting and image processing techniques using Matlab software. The spatial and temporal variation of both these parameters show a drastic increase during quenching in the wall-quenched case, while it remains nearly constant in the step quenched case. With increasing duct Reynolds number, the flame propagates slower, and the heat conduction to the wall leads to a decrease in the dead space and flattening of the flame, particularly at equivalence ratios corresponding to lower flame speeds. This flame-wall interaction is found to be low for methane, resulting in more heat loss and thereby wall-quenched flames compared to propane and ethylene. None of the ethylene flames were found to suffer wall quenching thereby making it a suitable fuel for meso-/micro-combustors among the three fuels used in the present work.

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Korobsky, V., S. Sobol, and S. Lapshin. "Coating thickness of the restored contact of electrical equipment and the method of its determination." Energy and automation, no. 6(52) (November 25, 2020): 28–44. http://dx.doi.org/10.31548/energiya2020.06.028.

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The regularities of the formation of the main variants of coatings obtained by gas-plasma spraying with subsequent liquid-phase sintering, depending on the conditions of wetting the powder particles with the melt and the porosity of the sprayed layer, have been established. The analysis of methods for controlling the thickness of thermal gas coatings, which indicates the advantages and disadvantages of three methods of measuring the thickness: magnetic, electromagnetic (eddy currents) and metallographic. The research of the dependence of the thermal power of the plasma jet (directly affects the thickness of the sprayed coating) on the thermal equivalent of the electric power of the arc was carried out; dependence is characterized by an effective efficiency. As a result of the research, the thickness of the sprayed coatings of the contacts and the tolerances for their processing were calculated depending on the height of the contact piece. Coating thickness is the shortest distance between the coating surface at a given point and the base metal surface. As a technological characteristic, the thickness affects such an important performance property as the strength of the bond with the base metal. Increasing the thickness of the coating above the optimum leads not only to a deterioration in quality (decrease in bond strength), but also to economic costs. The coating was applied to a given area due to the linear movement of the spray device in combination with either the transverse displacement of the spray device or contact piece. With a single linear movement of the spray device, the sprayed material forms a uniform coating layer, the cross-section of which is described by the Gaussian curve. The requirements for the thickness of the sprayed layer are indicated in the technological documentation, based on the uniformity of the distribution of the coating thickness on the contact surface. The required thickness of the sprayed coating was determined based on the thickness of the working layer, the tolerance for subsequent processing and the tolerance for the dimensions of the contact piece and the thickness of the sprayed layer. The thickness of the sprayed coating on the contacts, in which the lost dimensions are restored, provided for a tolerance for their following processing: turning and grinding. As a result, the thicknesses of the sprayed coatings of the contacts and the tolerances for their machining were calculated depending on the height of the contact piece (the number of switching cycles of the sprayed contact pieces). In thermal spraying of coatings, the build-up of parts occurs at a relatively high rate, that is, approximately 10 - 20 times faster than electrolytic deposition of steel and approximately 100 - 200 times faster than electrolytic chromium plating.

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Nayyar, Anand, Rudra Rameshwar, and Piyush Kanti Dutta. "Special Issue on Recent Trends and Future of Fog and Edge Computing, Services and Enabling Technologies." Scalable Computing: Practice and Experience 20, no. 2 (May 2, 2019): iii—vi. http://dx.doi.org/10.12694/scpe.v20i2.1558.

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Recent Trends and Future of Fog and Edge Computing, Services, and Enabling Technologies Cloud computing has been established as the most popular as well as suitable computing infrastructure providing on-demand, scalable and pay-as-you-go computing resources and services for the state-of-the-art ICT applications which generate a massive amount of data. Though Cloud is certainly the most fitting solution for most of the applications with respect to processing capability and storage, it may not be so for the real-time applications. The main problem with Cloud is the latency as the Cloud data centres typically are very far from the data sources as well as the data consumers. This latency is ok with the application domains such as enterprise or web applications, but not for the modern Internet of Things (IoT)-based pervasive and ubiquitous application domains such as autonomous vehicle, smart and pervasive healthcare, real-time traffic monitoring, unmanned aerial vehicles, smart building, smart city, smart manufacturing, cognitive IoT, and so on. The prerequisite for these types of application is that the latency between the data generation and consumption should be minimal. For that, the generated data need to be processed locally, instead of sending to the Cloud. This approach is known as Edge computing where the data processing is done at the network edge in the edge devices such as set-top boxes, access points, routers, switches, base stations etc. which are typically located at the edge of the network. These devices are increasingly being incorporated with significant computing and storage capacity to cater to the need for local Big Data processing. The enabling of Edge computing can be attributed to the Emerging network technologies, such as 4G and cognitive radios, high-speed wireless networks, and energy-efficient sophisticated sensors. Different Edge computing architectures are proposed (e.g., Fog computing, mobile edge computing (MEC), cloudlets, etc.). All of these enable the IoT and sensor data to be processed closer to the data sources. But, among them, Fog computing, a Cisco initiative, has attracted the most attention of people from both academia and corporate and has been emerged as a new computing-infrastructural paradigm in recent years. Though Fog computing has been proposed as a different computing architecture than Cloud, it is not meant to replace the Cloud. Rather, Fog computing extends the Cloud services to network edges for providing computation, networking, and storage services between end devices and data centres. Ideally, Fog nodes (edge devices) are supposed to pre-process the data, serve the need of the associated applications preliminarily, and forward the data to the Cloud if the data are needed to be stored and analysed further. Fog computing enhances the benefits from smart devices operational not only in network perimeter but also under cloud servers. Fog-enabled services can be deployed anywhere in the network, and with these services provisioning and management, huge potential can be visualized to enhance intelligence within computing networks to realize context-awareness, high response time, and network traffic offloading. Several possibilities of Fog computing are already established. For example, sustainable smart cities, smart grid, smart logistics, environment monitoring, video surveillance, etc. To design and implementation of Fog computing systems, various challenges concerning system design and implementation, computing and communication, system architecture and integration, application-based implementations, fault tolerance, designing efficient algorithms and protocols, availability and reliability, security and privacy, energy-efficiency and sustainability, etc. are needed to be addressed. Also, to make Fog compatible with Cloud several factors such as Fog and Cloud system integration, service collaboration between Fog and Cloud, workload balance between Fog and Cloud, and so on need to be taken care of. It is our great privilege to present before you Volume 20, Issue 2 of the Scalable Computing: Practice and Experience. We had received 20 Research Papers and out of which 14 Papers are selected for Publication. The aim of this special issue is to highlight Recent Trends and Future of Fog and Edge Computing, Services and Enabling technologies. The special issue will present new dimensions of research to researchers and industry professionals with regard to Fog Computing, Cloud Computing and Edge Computing. Sujata Dash et al. contributed a paper titled “Edge and Fog Computing in Healthcare- A Review” in which an in-depth review of fog and mist computing in the area of health care informatics is analysed, classified and discussed. The review presented in this paper is primarily focussed on three main aspects: The requirements of IoT based healthcare model and the description of services provided by fog computing to address then. The architecture of an IoT based health care system embedding fog computing layer and implementation of fog computing layer services along with performance and advantages. In addition to this, the researchers have highlighted the trade-off when allocating computational task to the level of network and also elaborated various challenges and security issues of fog and edge computing related to healthcare applications. Parminder Singh et al. in the paper titled “Triangulation Resource Provisioning for Web Applications in Cloud Computing: A Profit-Aware” proposed a novel triangulation resource provisioning (TRP) technique with a profit-aware surplus VM selection policy to ensure fair resource utilization in hourly billing cycle while giving the quality of service to end-users. The proposed technique use time series workload forecasting, CPU utilization and response time in the analysis phase. The proposed technique is tested using CloudSim simulator and R language is used to implement prediction model on ClarkNet weblog. The proposed approach is compared with two baseline approaches i.e. Cost-aware (LRM) and (ARMA). The response time, CPU utilization and predicted request are applied in the analysis and planning phase for scaling decisions. The profit-aware surplus VM selection policy used in the execution phase for select the appropriate VM for scale-down. The result shows that the proposed model for web applications provides fair utilization of resources with minimum cost, thus provides maximum profit to application provider and QoE to the end users. Akshi kumar and Abhilasha Sharma in the paper titled “Ontology driven Social Big Data Analytics for Fog enabled Sentic-Social Governance” utilized a semantic knowledge model for investigating public opinion towards adaption of fog enabled services for governance and comprehending the significance of two s-components (sentic and social) in aforesaid structure that specifically visualize fog enabled Sentic-Social Governance. The results using conventional TF-IDF (Term Frequency-Inverse Document Frequency) feature extraction are empirically compared with ontology driven TF-IDF feature extraction to find the best opinion mining model with optimal accuracy. The results concluded that implementation of ontology driven opinion mining for feature extraction in polarity classification outperforms the traditional TF-IDF method validated over baseline supervised learning algorithms with an average of 7.3% improvement in accuracy and approximately 38% reduction in features has been reported. Avinash Kaur and Pooja Gupta in the paper titled “Hybrid Balanced Task Clustering Algorithm for Scientific workflows in Cloud Computing” proposed novel hybrid balanced task clustering algorithm using the parameter of impact factor of workflows along with the structure of workflow and using this technique, tasks can be considered for clustering either vertically or horizontally based on value of impact factor. The testing of the algorithm proposed is done on Workflowsim- an extension of CloudSim and DAG model of workflow was executed. The Algorithm was tested on variables- Execution time of workflow and Performance Gain and compared with four clustering methods: Horizontal Runtime Balancing (HRB), Horizontal Clustering (HC), Horizontal Distance Balancing (HDB) and Horizontal Impact Factor Balancing (HIFB) and results stated that proposed algorithm is almost 5-10% better in makespan time of workflow depending on the workflow used. Pijush Kanti Dutta Pramanik et al. in the paper titled “Green and Sustainable High-Performance Computing with Smartphone Crowd Computing: Benefits, Enablers and Challenges” presented a comprehensive statistical survey of the various commercial CPUs, GPUs, SoCs for smartphones confirming the capability of the SCC as an alternative to HPC. An exhaustive survey is presented on the present and optimistic future of the continuous improvement and research on different aspects of smartphone battery and other alternative power sources which will allow users to use their smartphones for SCC without worrying about the battery running out. Dhanapal and P. Nithyanandam in the paper titled “The Slow HTTP Distributed Denial of Service (DDOS) Attack Detection in Cloud” proposed a novel method to detect slow HTTP DDoS attacks in cloud to overcome the issue of consuming all available server resources and making it unavailable to the real users. The proposed method is implemented using OpenStack cloud platform with slowHTTPTest tool. The results stated that proposed technique detects the attack in efficient manner. Mandeep Kaur and Rajni Mohana in the paper titled “Static Load Balancing Technique for Geographically partitioned Public Cloud” proposed a novel approach focused upon load balancing in the partitioned public cloud by combining centralized and decentralized approaches, assuming the presence of fog layer. A load balancer entity is used for decentralized load balancing at partitions and a controller entity is used for centralized level to balance the overall load at various partitions. Results are compared with First Come First Serve (FCFS) and Shortest Job First (SJF) algorithms. In this work, the researchers compared the Waiting Time, Finish Time and Actual Run Time of tasks using these algorithms. To reduce the number of unhandled jobs, a new load state is introduced which checks load beyond conventional load states. Major objective of this approach is to reduce the need of runtime virtual machine migration and to reduce the wastage of resources, which may be occurring due to predefined values of threshold. Mukta and Neeraj Gupta in the paper titled “Analytical Available Bandwidth Estimation in Wireless Ad-Hoc Networks considering Mobility in 3-Dimensional Space” proposes an analytical approach named Analytical Available Bandwidth Estimation Including Mobility (AABWM) to estimate ABW on a link. The major contributions of the proposed work are: i) it uses mathematical models based on renewal theory to calculate the collision probability of data packets which makes the process simple and accurate, ii) consideration of mobility under 3-D space to predict the link failure and provides an accurate admission control. To test the proposed technique, the researcher used NS-2 simulator to compare the proposed technique i.e. AABWM with AODV, ABE, IAB and IBEM on throughput, Packet loss ratio and Data delivery. Results stated that AABWM performs better as compared to other approaches. R.Sridharan and S. Domnic in the paper titled “Placement Strategy for Intercommunicating Tasks of an Elastic Request in Fog-Cloud Environment” proposed a novel heuristic IcAPER,(Inter-communication Aware Placement for Elastic Requests) algorithm. The proposed algorithm uses the network neighborhood machine for placement, once current resource is fully utilized by the application. The performance IcAPER algorithm is compared with First Come First Serve (FCFS), Random and First Fit Decreasing (FFD) algorithms for the parameters (a) resource utilization (b) resource fragmentation and (c) Number of requests having intercommunicating tasks placed on to same PM using CloudSim simulator. Simulation results shows IcAPER maps 34% more tasks on to the same PM and also increase the resource utilization by 13% while decreasing the resource fragmentation by 37.8% when compared to other algorithms. Velliangiri S. et al. in the paper titled “Trust factor based key distribution protocol in Hybrid Cloud Environment” proposed a novel security protocol comprising of two stages: first stage, Group Creation using the trust factor and develop key distribution security protocol. It performs the communication process among the virtual machine communication nodes. Creating several groups based on the cluster and trust factors methods. The second stage, the ECC (Elliptic Curve Cryptography) based distribution security protocol is developed. The performance of the Trust Factor Based Key Distribution protocol is compared with the existing ECC and Diffie Hellman key exchange technique. The results state that the proposed security protocol has more secure communication and better resource utilization than the ECC and Diffie Hellman key exchange technique in the Hybrid cloud. Vivek kumar prasad et al. in the paper titled “Influence of Monitoring: Fog and Edge Computing” discussed various techniques involved for monitoring for edge and fog computing and its advantages in addition to a case study based on Healthcare monitoring system. Avinash Kaur et al. elaborated a comprehensive view of existing data placement schemes proposed in literature for cloud computing. Further, it classified data placement schemes based on their assess capabilities and objectives and in addition to this comparison of data placement schemes. Parminder Singh et al. presented a comprehensive review of Auto-Scaling techniques of web applications in cloud computing. The complete taxonomy of the reviewed articles is done on varied parameters like auto-scaling, approach, resources, monitoring tool, experiment, workload and metric, etc. Simar Preet Singh et al. in the paper titled “Dynamic Task Scheduling using Balanced VM Allocation Policy for Fog Computing Platform” proposed a novel scheme to improve the user contentment by improving the cost to operation length ratio, reducing the customer churn, and boosting the operational revenue. The proposed scheme is learnt to reduce the queue size by effectively allocating the resources, which resulted in the form of quicker completion of user workflows. The proposed method results are evaluated against the state-of-the-art scene with non-power aware based task scheduling mechanism. The results were analyzed using parameters-- energy, SLA infringement and workflow execution delay. The performance of the proposed schema was analyzed in various experiments particularly designed to analyze various aspects for workflow processing on given fog resources. The LRR (35.85 kWh) model has been found most efficient on the basis of average energy consumption in comparison to the LR (34.86 kWh), THR (41.97 kWh), MAD (45.73 kWh) and IQR (47.87 kWh). The LRR model has been also observed as the leader when compared on the basis of number of VM migrations. The LRR (2520 VMs) has been observed as best contender on the basis of mean of number of VM migrations in comparison with LR (2555 VMs), THR (4769 VMs), MAD (5138 VMs) and IQR (5352 VMs).

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Haberka, M., A. Garcia Martin, P. Barbier, M. Pellegrino, A. Angelis, PJ Howlett, M. Madeira, et al. "Poster session 1GENERAL PRINCIPLESP194Ultrasound indexes of adipose tissue and lipid goals attainment in high and very high cardiovascular risk patientsTHE IMAGING EXAMINATIONP195Right ventricular global longitudinal strain provides higher prognostic value than right free wall longitudinal strain in patients with left heart diseaseP196Normal values of echocardiographlc left and right cardiac chambers dimensions as multifactorially determined by sex, level of physical activity, age, BMI, systolic blood pressure and heart rateAnatomy and physiology of the heart and great vesselsP197Echocardiographic phenotypes according to levels of oxygen consumption at peak exercise: findings from the EURO(pean) EX(ercise) population-based studyAnatomy and physiology of the heart and great vesselsP198Systemic vascular resistance and central arterial stiffness in relation to left ventricular geometry and diastolic function in essential hypertensionAssessment of diameters, volumes and massP199Left atrial diameter predicts a new diagnosis of paroxysmal atrial fibrillation in a population presenting with palpitationsP200Interventricular septum thickness and acute coronary syndromes: small differences, big prognostic influence?P201Detection of abdominal aortic aneurysm in a population referred for an ultrasonographyAssessments of haemodynamicsP202The ultrasound vector velocity method transverse oscillation validated in a flowrig with constant and pulsatile flow and in-vivo of blood flow in the ascending aortaASSESSMENT OF SYSTOLIC FUNCTIONP203Different types of left ventrical remodeling in children with arterial hypertensionP204Assessment of myocardial performance index in hypertensive patients with or without hyperuricemiaP205Strain echocardiography detects mild impairment of systolic function in patients with frequent premature ventricular contractionsP206Speckle tracking strain correlates better with functional capacity and hemodynamic burden than ejection fraction in patients with severe heart failureP207Prognostic value of 2D and 3D echocardiographic volumes, ejection fraction and strain as markers of abnormal left ventricular performanceP208Long-term prognostic value of left ventricular ejection fraction assessed by echocardiography and magnetic resonance imaging after acute STEMIP209Assessment of left ventricular function after percutaneous coronary intervention of chronic total occluded coronary artery by speckle tracking and cardiac magnetic resonanceP210Physiologic variations of tricuspid annular plane systolic excursion in healthy subjects: clinical and echocardiographic correlatesP211Predictors of incipient ventricular dysfunction with tyrosine kinase inhibitors in metastatic renal cell carcinomaAssessment of diastolic functionP212Disagreement between the American Society of Echocardiography (ASE) and gastroenterology-based guidelines for the diagnosis of diastolic dysfunction among patients with advanced liver diseaseP213Nomograms for mitral inflow doppler and tissue doppler velocities in caucasian childrenP215Diastolic function is impaired in women with angina pectoris and no obstructive coronary artery disease independently of coronary microvascular functionP216Clinical value of myocardial performance index in patients with isolated diastolic dysfunctionIschemic heart diseaseP217Cardiac imaging strategy is clinically more effective and at lower cost than traditional ETT strategy for the diagnosis of stable coronary artery diseaseP218Does the ESC clinical pretest probability score stratify our patients correctly? Validation with stress echocardiographyP219Incremental value of exercise echocardiography over exercise electrocardiography in a chest pain unit: a decision curve analysisP220A bedside echocardiographic score for risk stratification of ST-elevation myocardial infarction patients undergoing primary percutaneous coronary interventionP221Interventricular and intraventricular dyssynchrony in patients with Q-wave acute myocardial infarctionP222Comparison of tagging and tissue tracking for myocardial strain assessment at 1.5T and 3.0T following ST-segment elevation myocardial infarctionP223Left atrial strain rate evaluated by two-dimensional speckle tracking is predictor of left ventricular arrhythmias in STEMI patients treated by primary PCIP224Impact of percutaneous coronary intervention of chronic total oclussion on left ventricular function using speckle tracking and cardiac magnetic resonanceHeart valve DiseasesP225Clinical and echocardiographic characteristics of patients with low flow severe aortic stenosis and preserved ejection fractionP226Ventricular-arterial interplay in patients with severe aortic stenosis: additional role of wave intensity analysisP227Degenerative aortic stenosis: don't forget the vascular componentP228Reclassifying low gradient aortic stenosis with 3D transesophageal echocardiography and global longitudinal strainP229Importance of mitral regurgitation on pre- and postoperative clinical status and echocardiographic findings in patients with severe aortic stenosis admitted for aortic valve replacementsP230Aorto-septal angle and degenerative aortic stenosis: a case-control study stenosisP231Difference of sST2 level in mitral stenosis compare with control subjectsP232Velocity-time integral of aortic regurgitation: a novel echocardiographic marker in the evaluation of aortic regurgitation severityP233Color doppler 3D echocardiography-derived regurgitant volume in primary mitral regurgitation: a comparison of different techniques with magnetic resonanceP234Outcome of surgery for degenerative mitral regurgitationP235Mitral valve repair or replacement for functional regurgitation and left ventricular dysfunction: clinical and echocardiographic outcomeP236Prevalence, characteristics and prognosis of moderate to severe tricuspid regurgitation in patients with precapillary pulmonary hypertensionP237Management of late bioprosthetic mitral valve thrombosisP238Relationship between pulmonary venous flow and prosthetic mitral valve thrombosisP239Transcatheter aortic valve implantation does not reduce acutely valvuloarterial impedance in an elderly population with degenerative calcific aortic valve stenosisP240Influence of type of prosthesis on mitral regurgitation change after transcatheter aortic valve replacement for aortic stenosisP241The prevalence of valve disease in patients undergoing atrial fibrillation ablationCardiomyopathiesP242The prognostic value of lung ultrasound at discharge in heart failureP243Prognostic value of global longitudinal strain in non-ischaemic dilated cardiomyopathyP244Additional effect of high intensity exercise training to cardiac resynchronization in heart failure: the reduction on left venticular massP245Dobutamine-induced changes of longitundinal strain predicts longterm mortality in severe heart failureP246Myocardial fibrosis is not related to two-dimensional longitudinal strain in dilated cardiomyopathyP247Echocardiographic parameters are predictors of positive genetic study in a Portuguese population with hypertrophic cardiomyopathy: a multicentre studyP248Myocardial deformation techniques for the evaluation of the right ventricle in fabry diseaseP249Borderline hypertrophic cardiomyopathy or athlete's heart: what is the role for genetic testing in athletes?P250Isolated papillary muscle hypertrophy. Clinical, electrocardiographic and morphologic characteristicsP251Prognostic value of the assessment of left atrial deformation in hypertrophic cardiomyopathyP252Assessment of subtle echocardiographic changes may improve risk stratification of arrhythmias in early stages of arrhythmogenic right ventricular cardiomyopathy (ARVC)P253Long-term correlation of electrocardiography with structural echocardiography changes in patients with arrhythmogenic right ventricular cardiomyopathyP254Right ventricular strain and dyssynchrony assessment in arrhythmogenic right ventricular cardiomyopathy: a cardiac magnetic resonance feature-tracking studyP255Association of non compaction and hypertrophic cardiomyopathies, Noonan and long QT syndromesP256Predictors of mortality in patients with acute myocarditisP257Clinical characteristics and natural history of acute myocarditisP258One-beat 3dimensional echocardiography for the assessment of right ventricular function in heart transplant recipientsP259Hemodynamically irrelevant, non-surgery related pericardial effusion is a predictor of mortality in heart transplanted patientsSystemic diseases and other conditionsP260Left ventricular function as a cardiac marker of target organ damage in non-diabetic, never treated hypertensive patients: Camparison with microalbuminuriaP261Subclinical myocardial dysfunction in hypertensive patients with hyperuricemiaP262Can deformation indices (strain/strain rate) establish differential diagnosis in infiltrative cardiomyopathies?P263Prevalence and factors associated with inappropriately high left ventricular mass in patients with rheumatoid arthritisP264Echocardiographic evaluation of patients with end-stage liver disease, the importance of follow up after liver transplantationP265Cardiovasclular involvement in asymptomatic juvenile localized scleroderma patientsP267Can the left ventricular mechanics using speckle tracking echocardiography in pregnancy predict the new onset heart failure?P268What causes impaired exercise tolerance in HFpEF? Relative contribution from LV filling pressure and other factorsCongenital heart diseaseP269Pregnancy in patients with Ebsteins anomaly - echocardiographic and clinical studyP270Double aortic arch anomalies in clinical practiceP271Echocardiography as the essential imaging modality in congenital heart disease - first one to begin with and the one who staysMasses, tumors and sources of embolismP272Can the reduction of wall shear stress in diskinetic myocardial wall segments be used to predict trombogenicity?Diseases of the aortaP273The role of modified transoesophageal echocardiography for optimal access decision making for transcatheter aortic valve replacement proceduresStress echocardiographyP274Is aortic valve resistance different in patients with severe aortic stenosis and left ventricular fraction below 40% with low or high gradient?P275Does wall motion score index in dobutamine stress echocardiography predict syntax score in catheterization lab?P276Sex-related differences in peak stress left ventricular global longitudinal strain during dobutamine stress echocardiography in patients with significant coronary artery diseaseP277Exercise stress echocardiography complications: a 4-year single center experienceP278Reduced baseline left ventricular longitudinal systolic function is a marker of inducible myocardial ischemia in patients undergoing exercise echocardiographyP279Estimation of mean pulmonary arterial pressure based on right ventricle systolic pressure observed from exercise echocardiography among non-pulmonary hypertension with systemic sclerosisTransesophageal echocardiographyP280Transoesophageal echocardiography in patients with neuroendocrine tumour and carcinoid symptoms is safe without intravenous octreotideP281The feasibility and the clinical benefit of the cognitive-behavioral intervention for preparing patients for transesophageal echocardiographic studyP282Dynamic changes of mitral annulus shape in different types of mitral valve prolapse. A three-dimensional transoesophageal studyReal-time three-dimensional TEEP283Severe aortic stenosis: evaluation of effective and anatomy valve by 2D transthoracic echocardiography and 3D transesophageal echocardiographyP2843D-transeosphageal echocardiography usefulness for assessment of cardiac output in intensive care unit: an ultrasound versus thermodilution comparative study for patients under mechanical ventilationP285The predictive value of three-dimensional vena-contracta in determining the number of MitraClip devices needed during the procedure in functional mitral regurgitationTissue Doppler and speckle trackingP286Should the septum be included in the assessment of right ventricular longitudinal strain?P287Can machine learning help to identify heart failure with preserved ejection fraction?P288Concordance of atrial function measurement by 3D volumetric echocardiography and speckle tracking deformation imagingP289Heterogonous regional diastolic function revealed by 2D speckle tracking echocardiography identifies patients with ischemic etiology of left ventricular systolic dysfunctionP290The values from Real time 3-dimensional strain is not independent from preload changesP291Risk stratification in hypertrophic cardiomyopathy. a potential role for speckle-tracking parameters by cardiac magnetic resonanceP292Abnormal longitudinal peak systolic strain in asymptomatic patients with type-I diabetes mellitusP294Strain evaluation of subclinical cardiac dysfunction in patients with myotonic dystrophy type 1P295Heart function assessment in perinatal asphyxia; speckle tracking indices from greyscale recordings perform better than from tissue Doppler recordings, fractional shortening and tissue Doppler indicesP297Longitudinal strain assessed by automatic function imaging - a useful tool in significant coronary artery disease detection in patients with low risk anginaP298Global 2-Dimensional strain as a predictor of mortality in heart transplant patients with cardiac allograft vasculopathyP299Two-dimensional longitudinal strain and strain rate in asymptomatic middle-aged patients with type 2 diabetes mellitus - a pilot study resultsP300Limited accuracy of myocardial deformation imaging in diagnosis of left ventricular segmental dysfunction in patients with acute myocardial infarction: is it only a limitation of the strain software?Computed Tomography & Nuclear CardiologyP301Evaluation of the actual prevalence of myocardial ischemia in patients prior to performing a peripheral vascular surgeryP302Prognostic value of myocardial ischemia detected by myocardial perfusion imaging in asymptomatic patients with diabetes type 2P303Economic cost analysis derived by coronary computed tomography angiography inappropriate indications to rule out coronary heart disease." European Heart Journal – Cardiovascular Imaging 16, suppl 2 (December 2015): S15—S42. http://dx.doi.org/10.1093/ehjci/jev263.

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Lapinskas, Tomas, Chiodi Elisabetta, Chrysanthos Grigoratos, Ricardo Ladeiras-Lopes, GJ Fent, E. Abdul Rahman, Jonathan Rodrigues та ін. "VIEWING ONLY POSTERS1323Evaluation of right ventricular transverse strain and strain rate in patients with acute ST-segment elevation myocardial infarction: a cardiac magnetic resonance feature tracking study1333Cardiac resynchronization in ischemic heart failure patients: a comparison between therapy guided by cardiac magnetic resonance imaging and 2D-speckle tracking echocardiography1338Cardiac magnetic resonance versus bisphosphonate scintigraphy for diagnosis of cardiac amyloidosis1341Strain relaxation index, a novel tagged MRI-derived diastolic function parameter, is impaired in metabolic syndrome1349Global Longitudinal Strain Predicts Chronic Myocardial Infarction in Patients with Normal Ejection Fraction1352Optimal Dose Of Dobutamine During Low-Dose Dobutamine Stress Echocardiography In Correctly Identify Viable Segments On Cardiovascular Magnetic Resonance1368Absolute wall thickening and left ventricular ejection fraction–a unifying theory of myocardial contraction and heart failure?1376Transient St Elevation in Acs Like Myocarditis1379Patients after Fontan with a “total cavopulmonary connection” Fontan modification develop more collateral flow compared to “old-fashioned” Fontan modifications1387A MRI–derived 3D patient specific model for fibrosis quantification in atrial fibrillation1391Scar burden and survival in patients with ischemic cardiomyopathy and poor LV ejection fraction1392Relation of inflammatory markers with myocardial and microvascular injury in patients with reperfused ST- elevation myocardial infarction1406Equivalence of segmented conventional and fast single-shot late gadolinium enhancement (LGE) techniques for1410Cardiac Mri Appearances of Tuberculosis - A Review of Varied Presentations in India1415Atheroma burden, cardiac remodelling and epicardial fat: A comparison between healthy South Asian and European adults using Whole Body Cardiovascular MR1418Symptomatic Ventricular Arrhythmias: Diagnostic Yield of Cardiac Magnetic Resonance1421CMR assessment of aortic stiffness in asymptomatic low risk patients with type 2 diabetes mellitus1436Shock index as a predictor of myocardial damage and clinical outcome in ST-elevation myocardial infarction1451Combined biomarker testing for the prediction of microvascular obstruction after primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction1452A novel oscillometric technique compared with cardiac magnetic resonance for the assessment of aortic pulse wave velocity in ST-segment elevation myocardial infarction1456Aorto-pulmonary collaterals evaluated by CMR is associated to reduced “effective” cardiac index late after Fontan palliation1458Evaluation of pulmonary transit time and Pulmonary Blood Volume with first-pass perfusion CMR imaging in adult with repaired Congenital Heart disease1459Prognostic value of the cardiac magnetic resonance as a predictor of improvement in ventricular function after TakoTsubo syndrome1462Diagnostic performance of ECG detection of left atrial enlargement in patients with arterial hypertension relative to the cardiac magnetic resonance gold-standard: impact of obesity1463Utility of cardiac magnetic resonance imaging for diagnosis of cardiac sarcoidosis and prediction of therapeutic effects in patients with complete heart block and implanted magnetic resonance-conditional pacemaker: A multicenter study1467Cardiac magnetic resonance late gadolinium enhancement in patients with genetic dilated cardiomyopathy14712.Left ventricular hypertrophy in hypertensive patients–comparison of Cardiac Magnetic Resonance and Echocardiographic analysis of morphological and functional LV-parameters1472Is Angiographic Perfusion Score assessed in patients with acute myocardial infarction correlated with Cardiac Magnetic Resonance infarct size and N-terminal pro-brain natriuretic peptide in 6-month follow-up1476Cardiac Magnetic Resonance Patterns of Left Ventricular Diastolic Function In Hypertrophic Cardiomyopathy1477Impact of platelet volume on thrombus burden and tissue reperfusion in patients with STEMI treated with primary angioplasty: MRI study1479Right ventricle systolic function assessment and its prognostic implications in cardiac amyloidosis1484Cardiac MRI - an important tool in the evaluation of multsystemic inflamatory diseases. An Erdheim-Chester Disease case report1485Predictive value of cardiac magnetic resonance for future adverse cardiac events in patients with ST-segment elevation myocardial infarction1486Time-to-treatment but not thrombectomy influence infarct size and microvascular obstruction in patients with acute ST-segment elevation myocardial infarction treated with primary coronary intervention1489Primary PCI versus Early Routine Post Fibrinolysis PCI for ST Elevation Myocardial Infarction1490Evaluation of ventricular function in Fontan patients undergoing feature tracking magnetic resonance strain1491Impacts of atrialized right ventricle and left ventricular displacement in Ebstein's anomaly on left ventricular function assessed by cardiovascular MRI1494Final diagnosis for patients presenting with chest pain, electrocardiographic changes or troponin rise and normal coronary arteries: insights from Cardiovascular MRI in our population1495Early Predictive Factors of LV Remodeling after STEMI; Assessment by Coronary Angiogram and Cadiovascular Magnetic Resonance1497The Pathobiologic Mechanisms and the Prognostic Meaning of t wave Inversion in Acute Myocarditis. a Study Performed by Cardiac Magnetic Resonance1501The Influence of Left Atrial Function on Exercise Tolerance in Patients with Heart Failure and Preserved Ejection Fraction: A Cardiac Magnetic Resonance Feature Tracking Study1504Microvascular Obstruction in Patients with Anterior ST-Elevation Myocardial Infarction who Underwent Primary Percutaneous Coronary Intervention: Predictors and Impact on the Left Ventricular Function1508Histological Validation of ECV Quantification by Cardiac Magnetic Resonance T1 Mapping in Cardiac Amyloidosis1513Comparative Evaluation of Flow Quantification Across the Atrioventricular Valve in Patients with Functional Univentricular Heart After Fontan's Surgery and Healthy Controls: Measurement by 4D Flow Magnetic Resonance Imaging and Streamline Visualization1515Does arterial switch for d-transposition of the great arteries alter myocardial deformation of the ventricles?1527Accuracy of T1 Mapping by multi-professional CMR operators to predict myocardial infarct1531Detecting hypertensive heart disease: the additive value of cardiovascular magnetic resonance imaging1534Diagnostic Performance of Cardiac Magnetic Resonance Strain Parameters in Assesment of Myocardial Ischemia1535Relationships between left ventricular filling pressures and longitudinal dysfunction with myocardial fibrosis in uncomplicated hypertensive patients1539Predictive Clinical Factors of Tissue Damage Severity in Reperfused Acute Myocardial Infarction as Visualized by Cardiac Magnetic Resonance1541Which CMR derived parameter predicts better the need of invasive treatment in aortic coarctation?1543Contrast-enhanced magnetic resonance tomography in patients with supraventricular tachyarrhythmias1546Prognostic Value of CMR Imaging Biomarkers on Outcome in Peripheral Arterial Disease: a 6-year Follow-up Pilot Study1549Dobutamine-Stress-CMR in Young Adults after Arterial Switch Operation as Neonates1553Impact of posteromedial papillary muscle infarction on mitral regurgitation after ST-segment elevation myocardial infarction1556Role of cardiac magnetic resonance imaging in assessment of left ventricular hypertrophy1569Using intrinsic Cardiac Shear Waves to measure Myocardial Stiffness: Preliminary results from Patients with Heart failure with preserved Ejection Fraction1571Relationship of cerebrovascular reactivity and MRI pattern of carotid atherosclerotic plaque1577Feasibility study of an MR conditional pedal ergometer for cardiac stress MRI–preliminary results in healthy volunteers and patients with suspected coronary artery disease1581Pulmonary valve replacement for severe pulmonary stenosis has a positive effect on left ventricular remodeling1582The RV after cardiac surgery, more resilient than thought: multiparametric quantification shows altered rather than reduced function1584Usefulness of cardiovascular magnetic resonance to differentate coronary artery disease from non ischemic cardiomyoptathy in patients with heart failure1593What does CMR add to the ESC Risk Prediction Model to Assess the Occurrence of Sudden Cardiac Death in Patients with HCM?1597Detecting Progression of Diffuse Interstitial Fibrosis in Alstrom Syndrome1612Diffuse fibrosis in the ventricles of patients with transposition of great arteries late after atrial switch1631Utility of Cardiac Magnetic Resonance in the diagnosis and stratification of arrhythmic risk in patients with confirmed or suspected ventricular arrhythmias1635Size matters: pulmonary veins geometry by cardiac magnetic resonance imaging in atrial fibrillation patients1642How do the differences in Left Ventricular wall measurements from Echocardiography and CMR in patients with Hypertrophic Cardiomyopathy affect current Sudden Cardiac Death Risk Scores?1651Noninvasive assessment of intracardiac viscous energy loss in Fontan patients from 4D Flow CMR1653Behcet and Myocardial Infarction: A Rare Combination1328Impact of New Cerebral Ischemic Lesions On the Occurrence of Delirium after Transcatheter Aortic Valve Implantation1329Heart T2* assessment to measure iron overload using different software tools in patients with Thalassemia Major1332Hypertrabeculated Left Ventricle at Cardiac Magnetic Resonance Imaging: β-Thalassemia Major vs. Left Ventricular Non -Compaction Disease1335Aortic Regurgitation following Transcatheter Aortic Valve Implantation (TAVI): a CMR Study of two prosthesis designs1336Incremental value of semi-quantitative evaluation of myocardium perfusion with 3T stress cardiac MRI1343Left ventricular morphological quantification with single shot and free-breathing SSFP cine imaging compared with standard breath-hold SSFP cine imaging1344Changes of cardiac iron and function during pregnancy in transfusion-dependent thalassemia patients1346Significant improvement of survival by T2* MRI in thalassemia major1350The impact of trans-catheter aortic valve implantation induced left-bundle branch block on cardiac reverse remodelling1351Value of magnetic resonance myocardial perfusion imaging in patients with indeterminate coronary computed tomography angiography results1353Gender differences in response to Transcatheter Aortic Valve implantation in patients with severe aortic stenosis assessed by feature tracking1354A qualitative assessment of first-pass perfusion bolus timings in the assessment of myocardial ischemia: A magnetic resonance study1355MRI prospective survey on cardiac iron and function and on hepatic iron in non transfusion-dependent thalassemia intermedia patients treated with desferrioxamine or non chelated1358Coronary Calcification Compromises Myocardial Perfusion Irrespective of Luminal Stenosis1359Non–contrast three–dimensional magnetic resonance imaging for pre–procedural assessment of aortic annulus dimensions in patients undergoing transcatheter aortic valve implantation1360“Systolic ventricularization” of the left atrium with bileaflet mitral valve prolapse: impact on quantification of mitral regurgitation1361CMR assessment of left ventricular remodeling 6 months after percutaneous edge-to-edge repair using Mitraclip1363Accuracy of Transthoracic Echocardiography (TTE) in comparison with Cardiac Magnetic Resonance (CMR)1374CMR for myocardial iron overload assessment: a new calibration curve from the MIOT project1381Can Speckle Tracking Imaging Reveal Myocardial Iron Overload in Thalassemia Major? A Combined Echocardiography and Cardiac Magnetic Resonance Study1382Native myocardial T1 mapping in patients with pulmonary hypertension and age matched volunteers1384A Insidious Line Between Thalassemia Intermedia And Left Ventricular Non-Compaction Disease: The Role Of Cardiac Magnetic Resonance1388Pulmonary Artery : Ascending Aorta Diameter - An Important and Easily Measureable Prognostic Parameter1394Novel carotid artery ultrasound index–Extra-media thickness and a well-established cardiac magnetic resonance fat quantification method1403Validation of CMR-derived LVOT diameters against direct in-vivo measurements1409Early myocardial perfusion measured by CMR in acute myocardial infarction treated by primary PCI–a postconditioning study1420Assessment of paravalvular aortic regurgitation after transcatheter aortic valve implantation using cardiac magnetic resonance imaging: a comparative study with echocardiography and angiography1422Left atrial strain measured by feature tracking predicts left ventricular end diastolic filling pressure1426Validation of extracellular volume equation by serial cardiac magnetic resonance imaging measurements in patients with varying hematocrit1427Assessing diastolic function applying Cardiovascular Magnetic Resonance - comparison with the gold standard1475Role of Adenosine Stress Cardiac Mri in the Setting of Chronic Total Occlusion of Coronary Arteries1520Aortic Elasticity Indexes by Magnetic Resonance Predict Progression of Ascending Aorta Dilation1522Combined atrioventricular assessment of diastolic function by cardiac magnetic resonance1537Safety, image quality and clinical utility of cardiac magnetic resonance in patients with antiarrhythmic devices1538Usefulness of cardiac magnetic resonance to predict the need for surgical procedures in patients with mitral regurgitation1550Normal T1, T2, T2* and extracellular volume reference values in healthy volunteers at 3 Tesla cardiac magnetic resonance1551Comprehensive intra-ventricular myocardial deformation strain analysis in healthy volunteers: implications for regional myocardial disease processes1557Elastic properties changes of aorta in patients with dilatation of the ascending aorta evaluated by Magnetic Resonance1558The prevalence of active myocarditis assessed by cardiovascular magnetic resonance in patients with clinically suspected myocarditis1563Quantitative assessment of myocardial scar heterogeneity using texture analysis to risk stratify post–MI patients for ICD insertion1564Gender differences in exercise capacity and LV remodeling in response to pressure overload in aortic stenosis1572Myocardial wall stress as a novel CMR measure to assess cardiac function1573Feature tracking cardiac magnetic resonance to assess LV mechanics in pressure and volume overload1574Safety, feasibility and clinical impact of Cardiovascular Magnetic Resonance in patients with MR-conditional devices1576T1 Mapping at 1-Year Following Aortic Valve Replacement: Baseline Geometry Defines Magnitude of Fibrosis Regression1583Normal values of LV global myocardial mechanics using two and three-dimensional cardiovascular magnetic resonance1585Prediction of infarct transmurality in acute myocardial infarction based on cardiac magnetic resonance deformation analysis1595Measuring invasive blood pressure by catheters guided solely by Cardiovascular Magnetic Resonance by using a new guidewire without the need of a hybrid CMR-fluoroscopy suite1599Influence of active and passive cardiac implants on CMR image quality: results from a consecutive patient series1600Reproducibility of aortic 4D flow measurements in healthy volunteers1601An automatic approach to extract 4D flow hemodynamic markers: application in BAV-affected patients1602Global myocardial mechanics with 2 and 3-Dimensional cardiovascular magnetic resonance feature tracking in patients with myocarditis1603A CMR-based clinician-friendly assessment of in vivo left ventricle hemodynamics1604Reproducibility of left atrial strain using cardiovascular magnetic resonance myocardial feature tracking1605The severity of myocardial infarction in STEMI, determined by transmurality of infarct and infarct characteristics, impacts on myocardial T2 values1606MicroRNA as potential biomarkers of acute myocardial damage following STEMI1607Myocardial blush grade is associated with microvascular obstruction on CMR following STEMI16084D Flow CMR imaging: Comparison of conventional parallel imaging and variable density k-t acceleration1609In-vitro comparison of segmented-gradient-echo versus non-segmented echo planar imaging 4D Flow CMR: validation of flow volume and 3D vortex ring assessment1614Not just 2D but also 4D flow measurements in pulsatile phantom are accurate and reproducible1615Diffusion Tensor Imaging: Comparison of Hypertrophic Cardiomyopathy, Hypertension and Healthy Cohorts1624Impact of myocardial fibrosis measured by cardiac magnetic resonance imaging on reverse left ventricular remodelling after transcatheter aortic valve implantation1625Prosthetic valve regurgitation after transcatheter aortic valve implantation with new-generation devices compared to surgical aortic valve replacement–a cardiac magnetic resonance imaging flow measurement analysis1637Assessment of Aortic and Pulmonary Artery stiffness in Patients with COPD using Cardiac Magnetic Resonance1638Myocardial Mechanics implications using 2D Cardiovascular Magnetic Resonance in Aortic Regurgitation1639Delineation of myocardial infarction & viability by 12 lead ECG vs cardiac magnetic resonance1641Regional variation in native T1 values in normal healthy volunteers?1645Feasibility of myocardial strain assessment using tissue tracking at 3.0T CMR following ST-segment elevation myocardial infarction1648Diagnostic Impact of Cardiac Magnetic Resonance in patients with acute chest pain, troponin elevation and no significant angiographic coronary artery disease". European Heart Journal – Cardiovascular Imaging 17, suppl 1 (травень 2016): i37—i84. http://dx.doi.org/10.1093/ehjci/jew183.

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37

ITABA, AYAKO, and MASAKI MATSUNO. "AS-REGULARITY OF GEOMETRIC ALGEBRAS OF PLANE CUBIC CURVES." Journal of the Australian Mathematical Society, June 22, 2021, 1–25. http://dx.doi.org/10.1017/s1446788721000070.

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Abstract In noncommutative algebraic geometry an Artin–Schelter regular (AS-regular) algebra is one of the main interests, and every three-dimensional quadratic AS-regular algebra is a geometric algebra, introduced by Mori, whose point scheme is either $\mathbb {P}^{2}$ or a cubic curve in $\mathbb {P}^{2}$ by Artin et al. [‘Some algebras associated to automorphisms of elliptic curves’, in: The Grothendieck Festschrift, Vol. 1, Progress in Mathematics, 86 (Birkhäuser, Basel, 1990), 33–85]. In the preceding paper by the authors Itaba and Matsuno [‘Defining relations of 3-dimensional quadratic AS-regular algebras’, Math. J. Okayama Univ. 63 (2021), 61–86], we determined all possible defining relations for these geometric algebras. However, we did not check their AS-regularity. In this paper, by using twisted superpotentials and twists of superpotentials in the Mori–Smith sense, we check the AS-regularity of geometric algebras whose point schemes are not elliptic curves. For geometric algebras whose point schemes are elliptic curves, we give a simple condition for three-dimensional quadratic AS-regular algebras. As an application, we show that every three-dimensional quadratic AS-regular algebra is graded Morita equivalent to a Calabi–Yau AS-regular algebra.

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Liu, Wenrui, Jianwei Sun, and Jinkui Chu. "Synthesis of a Spatial RRSS Mechanism for Path Generation Using the Numerical Atlas Method." Journal of Mechanical Design 142, no. 1 (October 3, 2019). http://dx.doi.org/10.1115/1.4044110.

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Abstract An open path synthesis method for a spatial revolute-revolute-spherical-spherical (RRSS) mechanism is presented in this paper. The mathematical model for the trajectory curve is established. The characteristics of an RRSS mechanism in a standard installation position are revealed: the projection points of the coupler curve on the Oxy plane rotate by the corresponding input angles around the z-axis, and the generated points lie on an ellipse. Based on this finding, a 17-dimensional path generation problem can be translated into two lower-dimensional matching recognition problems and one actual size and installation position calculation problem. The path generation can be achieved by three steps. First, a database of four dimensional rotation angle parameters is established. By comparing the similarities between the mechanism feature curve of the prescribed open curve and its corresponding mechanism feature ellipse (MFE), the angles of installation, the initial angle of the input link, and the elliptic feature parameters of the desired RRSS mechanism can be approximately determined. Then, a 13-dimensional dynamic self-adapting numerical atlas database is established, which contains six basic dimensional types (BDTs) and seven wavelet feature parameters, and the BDTs of the desired RRSS mechanism are obtained. Finally, based on the relationship between the MFE of the prescribed curve and the BDTs of the desired RRSS mechanism, the calculation models for the actual link lengths and installation positions of the desired RRSS mechanism were established. Three examples are presented in this paper.

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Chen, Yang-zhi, Xiao-yan Fu, Jiang Ding, and Shun-ke Liang. "Geometric Design of Micro-Reducer With Multi-Output Shafts Distributed in Regular Polygon Form." Journal of Mechanical Design 135, no. 5 (April 23, 2013). http://dx.doi.org/10.1115/1.4024084.

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Based on the theory of space curve meshing, a space curve meshing wheel (SCMW) transmission mechanism has been invented by present authors in recent years. To extend applications of the SCMW, design methods for a novel micro-reducer with multioutput shafts distributed in regular polygon form is proposed in the paper. It is featured with three regular polygons nested. The middle regular polygon, named as reference regular polygon (RRP), is composed of transmission shafts. Three aspects are proposed as below to design the reducer: first, primary design parameters are determined by research and experience, and formulas of center distances are derived; second, an approach to establish the analytical model of the RRP simply and effectively is presented, which shows that the geometric dimensions of the reducer mainly depend on the side length of the RRP; and third, the novel micro-reducer is determined after the side length formulas of the RRP derived from the model. The simplicity and effectiveness of the formulas presented are demonstrated by a series of computational simulations.

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40

Carrillo, Hugo, and Alden Waters. "Recovery of a Lamé parameter from displacement fields in nonlinear elasticity models." Journal of Inverse and Ill-posed Problems, April 24, 2021. http://dx.doi.org/10.1515/jiip-2020-0142.

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Abstract We study some inverse problems involving elasticity models by assuming the knowledge of measurements of a function of the displaced field. In the first case, we have a linear model of elasticity with a semi-linear type forcing term in the solution. Under the hypothesis the fluid is incompressible, we recover the displaced field and the second Lamé parameter from power density measurements in two dimensions. A stability estimate is shown to hold for small displacement fields, under some natural hypotheses on the direction of the displacement, with the background pressure fixed. On the other hand, we prove in dimensions two and three a stability result for the second Lamé parameter when the displacement field follows the (nonlinear) Saint-Venant model when we add the knowledge of displaced field solution measurements. The Saint-Venant model is the most basic model of a hyperelastic material. The use of over-determined elliptic systems is new in the analysis of linearization of nonlinear inverse elasticity problems.

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Silva, J. W. E. W. De, and S. P. Abeysundara. "Statistical Analysis of Flow Parameters for the Graphical Simulation Outputs." Asian Research Journal of Mathematics, December 19, 2021, 1–10. http://dx.doi.org/10.9734/arjom/2021/v17i1230344.

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System dynamics simulation software, in general, depicts graphical interpretations. The values of the parameters, on the other hand, are required for prediction. The goal of this research is to develop a novel multivariate model that can predict flow parameters while simulating flow under various scenarios. The project involves looking for variations in the streamline and constructing a new multivariate model for each elliptic cylinder system's velocity magnitude. Furthermore, the flow zones were split into three groups based on streamline behavior. As a result, utilizing simulation outputs, new models for flow zones are developed using linear and semiparametric regression. The best fitted model for each flow region was determined using mean square error (MSE), root of mean square error (RMSE), and mean absolute percentage error (MAPE). Based on the fitted smoothing curve of the velocity magnitude, a summary statistic and variability may be assessed. The presented models can be used to predict magnitude in any point of fluid flow using these models.

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Tawackolian, Karsten, and Martin Kriegel. "Turbulence model performance for ventilation components pressure losses." Building Simulation, June 25, 2021. http://dx.doi.org/10.1007/s12273-021-0803-x.

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AbstractThis study looks to find a suitable turbulence model for calculating pressure losses of ventilation components. In building ventilation, the most relevant Reynolds number range is between 3×104 and 6×105, depending on the duct dimensions and airflow rates. Pressure loss coefficients can increase considerably for some components at Reynolds numbers below 2×105. An initial survey of popular turbulence models was conducted for a selected test case of a bend with such a strong Reynolds number dependence. Most of the turbulence models failed in reproducing this dependence and predicted curve progressions that were too flat and only applicable for higher Reynolds numbers. Viscous effects near walls played an important role in the present simulations. In turbulence modelling, near-wall damping functions are used to account for this influence. A model that implements near-wall modelling is the lag elliptic blending k-ε model. This model gave reasonable predictions for pressure loss coefficients at lower Reynolds numbers. Another example is the low Reynolds number k-ε turbulence model of Wilcox (LRN). The modification uses damping functions and was initially developed for simulating profiles such as aircraft wings. It has not been widely used for internal flows such as air duct flows. Based on selected reference cases, the three closure coefficients of the LRN model were adapted in this work to simulate ventilation components. Improved predictions were obtained with new coefficients (LRNM model). This underlined that low Reynolds number effects are relevant in ventilation ductworks and give first insights for suitable turbulence models for this application. Both the lag elliptic blending model and the modified LRNM model predicted the pressure losses relatively well for the test case where the other tested models failed.

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Huang, Xueying, Chun Yang, Gador Canton, Marina Ferguson, Chun Yuan, and Dalin Tang. "Quantifying Effect of Intraplaque Hemorrhage on Critical Plaque Wall Stress in Human Atherosclerotic Plaques Using Three-Dimensional Fluid-Structure Interaction Models." Journal of Biomechanical Engineering 134, no. 12 (November 27, 2012). http://dx.doi.org/10.1115/1.4007954.

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Recent magnetic resonance studies have indicated that intraplaque hemorrhage (IPH) may accelerate plaque progression and play an important role in plaque destabilization. However, the impact of hemorrhage on critical plaque wall stress (CPWS) and strain (CPWSn) has yet to be determined. The objective of this study was to assess the effect of the presence and size of IPH on wall mechanics. The magnetic resonance image (MRI) of one patient with histology-confirmed IPH was used to build eight 3D fluid-structure interaction (FSI) models by altering the dimensions of the existing IPH. As a secondary end point, the combined effect of IPH and fibrous cap thickness (FCT) was assessed. A volume curve fitting method (VCFM) was applied to generate a mesh that would guarantee numerical convergence. Plaque wall stress (PWS), strain (PWSn), and flow shear stress (FSS) were extracted from all nodal points on the lumen surface for analysis. Keeping other conditions unchanged, the presence of intraplaque hemorrhage caused a significant increase (27.5%) in CPWS; reduced FCT caused an increase of 22.6% of CPWS. Similar results were found for CPWSn. Furthermore, combination of IPH presence, reduced FCT, and increased IPH volume caused an 85% and 75% increase in CPWS and CPWSn, respectively. These results show that intraplaque hemorrhage has considerable impact on plaque stress and strain conditions and accurate quantification of IPH could lead to more accurate assessment of plaque vulnerability. Large-scale studies are needed to further validate our findings.

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Zhou, Jie, Qian Mao, Jun Zhang, Newman ML Lau, and Jianming Chen. "Selection of breast features for young women in northwestern China based on the random forest algorithm." Textile Research Journal, September 7, 2021, 004051752110408. http://dx.doi.org/10.1177/00405175211040869.

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In the research of breast morphology, numerous breast features are measured, whereas only a few parameters are adopted for classification. Therefore, how to extract the key variables from the multi-dimensional features in a rational way is an issue that is focused upon. This study aimed to reduce the complexity of the dimensionality reduction for further improving the objectivity and interpretability of the selected breast features. Since the random forest (RF) algorithm can quantify the feature importance during training, the method was adopted to determine the optimal breast features for classification and recognition in this paper. Firstly, the anthropometric data of 360 females from northwestern China aged from 19 to 27 years were measured by non-contact three-dimensional body scanning technology and the contact manual measurement method. Then, the k-means clustering was applied to categorize breast shapes, and the RF algorithm was utilized to quantify and rank the importance of 25 breast features. Finally, to verify the availability of the RF algorithm on breast feature selection, the t-distributed stochastic neighbor embedding method was adopted to visualize the distribution of breast shape clusters into two dimensions. Meanwhile, four neural networks were determined to recognize the breast morphology. The results demonstrate that fewer breast features can effectively increase the accuracy of breast shape classification and recognition. The best performance of breast shape classification and recognition is obtained when the number of breast features is 13. In this case, the average Hamming loss of four neural networks is the smallest (0.1136). Interestingly, the bust circumference and the horizontal curve of breasts across the bust points are found to be the most important of the 25 breast features in this paper. The importance of the breast curve features is higher than that of the breast cross-sectional features, while the breast positioning features have the lowest importance. Meanwhile, the RF algorithm is verified to be more effective than traditional dimensionality reduction methods, such as principal component analysis, hierarchical clustering, and recursive feature elimination. The approach developed in this paper can be generalized to the dimensionality reduction of other body morphology.

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