Smoothing Scale Research Articles

Evaluation in the Sit-and-Reach Flexibility Test

Abstract The research in this paper aims to correct evaluation tables of the modified flexibility sit-and-reach test, avoiding unreasonable great fluctuations in the scales. A human body model in the test, as a kinematic chain, including trunk and upper-extremity members connected with rotated joints, is proposed. An integral parameter of hip rotation and spine-bend flexibility is derived as an angle between the hip to shoulder straight line and horizon. The corresponding error of the angle in the frames of the simplified model appears to be nearly 1.5 %. The bend of trunk member is investigated, and its modeling with the integral parameter of flexibility causes an error of the fingertips displacement of nearly 0.4 cm, which is smaller than an error of the test score recorder. Two smooth evaluation scales are modeled with a linear function and with a logarithmic function. Corresponding tables for proportional evaluation and for rapidly increased mark values on the higher test scores are derived.

Application of the complex scaling method in solving three-body Coulomb scattering problem

The three-body scattering problem in Coulombic systems is a widespread, yet unresolved problem using the mathematically rigorous methods. In this work this long-term challenge has been undertaken by combining distorted waves and Faddeev–Merkuriev equation formalisms in conjunction with the complex scaling technique to overcome the difficulties related with the boundary conditions. Unlike the common belief, it is demonstrated that the smooth complex scaling method can be applied to solve the three-body Coulomb scattering problem in a wide energy region, including the fully elastic domain and extending to the energies well beyond the atom ionization threshold. A newly developed method is used to study electron scattering on the ground states of hydrogen and positronium atoms as well as a reaction. Where available, obtained results are compared with the experimental data and theoretical predictions, proving the accuracy and efficiency of the newly developed method.

Advanced Microstructural Investigations of AISI 441 Early Stage Oxidation in Wet Atmosphere

AISI 441 ferritic stainless steel is a good candidate for metallic interconnects in solid oxide fuel cells (SOFCs). The minor elements Ti and Nb are used to stabilize the ferritic matrix and also to reduce creep by a combination of solid solution strengthening and precipitation of intermetallic Laves phase particles along the grain boundaries. However their influence on the oxidation behavior is not well understood. This study focuses on the early stages oxidation (from 4 to 24 h) at 800 °C of AISI 441 under 5% H2O in O2. A relatively smooth micro-crystallized oxide scale and Ti, Nb containing nodules are observed. The internal microstructure of these objects is studied by FIB tomography which allows computing cross sectional views in any direction of interest. FIB study reveals a complex microstructure and a development strongly linked to the presence of niobium and/or titanium in the substrate.

The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Effect of smoothing of density field on reconstruction and anisotropic BAO analysis.

The reconstruction algorithm introduced by Eisenstein et al., which is widely used in clustering analysis, is based on the inference of the first-order Lagrangian displacement field from the Gaussian smoothed galaxy density field in redshift space. The smoothing scale applied to the density field affects the inferred displacement field that is used to move the galaxies, and partially erases the non-linear evolution of the density field. In this article, we explore this crucial step in the reconstruction algorithm. We study the performance of the reconstruction technique using two metrics: first, we study the performance using the anisotropic clustering, extending previous studies focused on isotropic clustering; secondly, we study its effect on the displacement field. We find that smoothing has a strong effect in the quadrupole of the correlation function and affects the accuracy and precision with which we can measure DA(z) and H(z). We find that the optimal smoothing scale to use in the reconstruction algorithm applied to Baryonic Oscillations Spectroscopic Survey-Constant (stellar) MASS (CMASS) is between 5 and 10 h−1 Mpc. Varying from the ‘usual’ 15–5 h−1 Mpc shows ∼0.3 per cent variations in DA(z) and ∼0.4 per cent H(z) and uncertainties are also reduced by 40 per cent and 30 per cent, respectively. We also find that the accuracy of velocity field reconstruction depends strongly on the smoothing scale used for the density field. We measure the bias and uncertainties associated with different choices of smoothing length.

Cnemaspis flaviventralis, a new species of gecko (Squamata: Gekkonidae) from the Western Ghats of Maharashtra, India

Cnemaspis flaviventralis, a new species of day gecko, is described from the forests of Amboli, Sindhudurg District, Maharashtra State, northern Western Ghats, India. The new species was previously confused with the sympatric species Cnemaspis girii, C. indraneildasii, C. kolhapurensis and C. goaensis. It is distinguished from C. giri by having spine-like tubercles on flanks, granular dorsal scales intermixed with large, depressed, slightly keeled scales (vs. lack of spine-like tubercles on flanks, granular dorsal scales, intermixed with large smooth scales); from C. indraneildasii by having dorsal scales heterogeneous (vs. homogenous), lacking a series of enlarged median sub-caudal scales, and 28–29 (vs. 20) ventral scales across mid-body; from C. kolhapurensis by having heterogeneous (vs. homogenous) dorsal scalation, lacking spine-like tubercles on flanks and lacking pre-cloacal pores (vs. 24–28 pre-cloacal-femoral pores); and from C. goaensis by lacking pre-cloacal pores and lacking a series of enlarged median sub-caudal scales. We further provide partial mitochondrial 16S rRNA gene sequences for the new species and for the sympatric species C. girii, C. kolhapurensis and C. goaensis, and show that the new species is genetically distinct.

Disentangling the origins of torque enhancement through wall roughness in Taylor–Couette turbulence

Direct numerical simulations (DNS) are performed to analyse the global transport properties of turbulent Taylor–Couette flow with inner rough wall up to Taylor number$Ta=10^{10}$. The dimensionless torque $Nu_{\unicode[STIX]{x1D714}}$ shows an effective scaling of $Nu_{\unicode[STIX]{x1D714}}\propto Ta^{0.42\pm 0.01}$, which is steeper than the ultimate regime effective scaling $Nu_{\unicode[STIX]{x1D714}}\propto Ta^{0.38}$ seen for smooth inner and outer walls. It is found that at the inner rough wall, the dominant contribution to the torque comes from the pressure forces on the radial faces of the rough elements; while viscous shear stresses on the rough surfaces contribute little to $Nu_{\unicode[STIX]{x1D714}}$. Thus, the log layer close to the rough wall depends on the roughness length scale, rather than on the viscous length scale. We then separate the torque contributed from the smooth inner wall and the rough outer wall. It is found that the smooth wall torque scaling follows $Nu_{s}\propto Ta_{s}^{0.38\pm 0.01}$, in excellent agreement with the case where both walls are smooth. In contrast, the rough wall torque scaling follows $Nu_{r}\propto Ta_{r}^{0.47\pm 0.03}$, very close to the pure ultimate regime scaling $Nu_{\unicode[STIX]{x1D714}}\propto Ta^{1/2}$. The energy dissipation rate at the wall of an inner rough cylinder decreases significantly as a consequence of the wall shear stress reduction caused by the flow separation at the rough elements. On the other hand, the latter shed vortices in the bulk that are transported towards the outer cylinder and dissipated. Compared to the purely smooth case, the inner wall roughness renders the system more bulk dominated and thus increases the effective scaling exponent.

Approach and separation of quantised vortices with balanced cores

The scaling laws for the reconnection of isolated pairs of quantised vortices are characterised by numerically integrating the three-dimensional Gross–Pitaevskii equations, the simplest mean-field equations for a quantum fluid. The primary result is the identification of distinctly different temporal power laws for the pre- and post-reconnection separation distances $\unicode[STIX]{x1D6FF}(t)$ for two configurations. For the initially anti-parallel case, the scaling laws before and after the reconnection time $t_{r}$ obey the dimensional $\unicode[STIX]{x1D6FF}\sim |t_{r}-t|^{1/2}$ prediction with temporal symmetry about $t_{r}$ and physical space symmetry about the mid-point between the vortices $x_{r}$. The extensions of the vortex lines close to reconnection form the edges of an equilateral pyramid. For all of the initially orthogonal cases, $\unicode[STIX]{x1D6FF}\sim |t_{r}-t|^{1/3}$ before reconnection and $\unicode[STIX]{x1D6FF}\sim |t-t_{r}|^{2/3}$ after reconnection are respectively slower and faster than the dimensional prediction. For both configurations, smooth scaling laws are generated due to two innovations. The first innovation is to use an initial low-energy vortex-core density profile that suppresses unwanted density fluctuations as the vortices evolve in time. The other innovation is the accurate identification of the position of the vortex cores from a pseudo-vorticity constructed on the three-dimensional grid from the gradients of the wave function. These trajectories allow us to calculate the Frenet–Serret frames and the curvature of the vortex lines, secondary results that might hold clues for the origin of the differences between the scaling laws of the two configurations. Reconnection takes place in a reconnection plane defined by the average tangents $\boldsymbol{T}_{av}$ and curvature normal $\boldsymbol{N}_{av}$ directions of the pseudo-vorticity curves at the points of closest approach, at time $t\approx t_{r}$. To characterise the structure further, lines are drawn that connect the four arms that extend from the reconnection plane, from which four angles $\unicode[STIX]{x1D703}_{i}$ between the lines are defined. Their sum is convex or hyperbolic, that is $\sum _{i=1,4}\unicode[STIX]{x1D703}_{i}>360^{\circ }$, for the orthogonal cases, as opposed to the acute angles of the pyramid found for the anti-parallel initial conditions.

Stability of the time-dependent configuration-interaction-singles method in the attosecond and strong-field regimes: A study of basis sets and absorption methods

We investigate the behavior of several spatial grid methods and complex absorbers for strong-field and attosecond scenarios when using the time-dependent configuration-interaction singles method to solve the multi-electron time-dependent Schr\"odinger equation for atoms. We compare the pseudospectral grid, finite-element, and finite-element-discrete-variable-representation (DVR) methods with each other and discuss their advantages and disadvantages. Additionally, we study the performances of complex absorbing potential (CAP) and smooth exterior complex scaling (SES) to absorb the outgoing electron. We find that SES performs generally better than CAP for calculating high-harmonic generation spectra and XUV photoelectron spectra. In both of these cases, the DVR and even more the FEM grid representations show more reliable results---especially when using SES. Both absorbers show drawbacks when calculating photoelectron spectra in the strong-field regime.

A new model to predict weak-lensing peak counts

This is the third in a series of papers that develop a new and flexible model to predict weak-lensing (WL) peak counts, which have been shown to be a very valuable non-Gaussian probe of cosmology. In this paper, we compare the cosmological information extracted from WL peak counts using different filtering techniques of the galaxy shear data, including linear filtering with a Gaussian and two compensated filters (the starlet wavelet and the aperture mass), and the nonlinear filtering method MRLens. We present improvements to our model that account for realistic survey conditions, which are masks, shear-to-convergence transformations, and non-constant noise. We create simulated peak counts from our stochastic model, from which we obtain constraints on the matter density $\Omega_\mathrm{m}$, the power spectrum normalisation $\sigma_8$, and the dark-energy parameter $w_0$. We use two methods for parameter inference, a copula likelihood, and approximate Bayesian computation (ABC). We measure the contour width in the $\Omega_\mathrm{m}$-$\sigma_8$ degeneracy direction and the figure of merit to compare parameter constraints from different filtering techniques. We find that starlet filtering outperforms the Gaussian kernel, and that including peak counts from different smoothing scales helps to lift parameter degeneracies. Peak counts from different smoothing scales with a compensated filter show very little cross-correlation, and adding information from different scales can therefore strongly enhance the available information. Measuring peak counts separately from different scales yields tighter constraints than using a combined peak histogram from a single map that includes multiscale information. Our results suggest that a compensated filter function with counts included separately from different smoothing scales yields the tightest constraints on cosmological parameters from WL peaks.

An analogue of the Littlewood–Paley theorem for orthoprojectors onto wavelet subspaces

We prove an analogue of the Littlewood–Paley theorem for orthoprojectors onto wavelet subspaces corresponding to a non-isotropic multiresolution analysis generated by the tensor product of smooth scaling functions of one variable with sufficiently rapid decay at infinity.

Minimax theory for a class of nonlinear statistical inverse problems

We study a class of statistical inverse problems with nonlinear pointwise operators motivated by concrete statistical applications. A two-step procedure is proposed, where the first step smoothes the data and inverts the nonlinearity. This reduces the initial nonlinear problem to a linear inverse problem with deterministic noise, which is then solved in a second step. The noise reduction step is based on wavelet thresholding and is shown to be minimax optimal (up to logarithmic factors) in a pointwise function-dependent sense. Our analysis is based on a modified notion of Hölder smoothness scales that are natural in this setting.

Indels ascertain the phylogenetic position of Coleodactylus elizae Gonçalves, Torquato, Skuk & Sena, 2012 (Gekkota: Sphaerodactylidae).

The Neotropical gecko genus Coleodactylus Parker 1926 was, until recently, composed of five species: C. amazonicus (Andersson 1918), C. brachystoma (Amaral 1935), C. meridionalis (Boulenger 1888), C. natalensis Freire 1999, and C. septentrionalis Vanzolini 1980 (Geurgas et al. 2008). However, several phylogenetic analyses recovered a polyphyletic Coleodactylus (Geurgas et al. 2008; Gamble et al. 2011a) leading Gamble et al. (2011b) to recognize a new genus, Chatogekko, for C. amazonicus. Coleodactylus and Chatogekko differ in both morphological and molecular characters. Coleodactylus has smooth dorsal scales and five scales forming the ungual sheath, while Chatogekko has keeled dorsal scales and four scales forming the ungual sheath (Gamble et al. 2011b). Furthermore, all Coleodactylus species have two deletions in the protein coding recombination-activating gene 1 (RAG1), one of six base pairs (bp) and another of 18 bp (Gamble et al. 2008a; Geurgas et al. 2008), while Chatogekko has a unique three bp deletion in the RBMX gene and a three bp deletion in the protein tyrosine phosphatase nonreceptor type 12 gene (PTPN12) (Gamble et al. 2011b). In addition, Chatogekko is differentiated from all others geckos by a unique set of 10 craniofacial features (Gamble et al. 2011b).

SHADOW OF A COLOSSUS: A z = 2.44 GALAXY PROTOCLUSTER DETECTED IN 3D Lyα FOREST TOMOGRAPHIC MAPPING OF THE COSMOS FIELD

ABSTRACT Using moderate-resolution optical spectra from 58 background Lyman-break galaxies and quasars at z ∼ 2.3 – 3 ?> within a 11.′5 × 13.′5 area of the COSMOS field ( ∼ 1200 deg - 2 ?> projected area density or ∼ 2.4 h - 1 Mpc ?> mean transverse separation), we reconstruct a 3D tomographic map of the foreground Lyα forest absorption at 2.2 < z < 2.5 with an effective smoothing scale of ϵ 3D ≈ 2.5 h - 1 Mpc ?> comoving. Comparing with 61 coeval galaxies with spectroscopic redshifts in the same volume, we find that the galaxy positions are clearly biased toward regions with enhanced intergalactic medium (IGM) absorption in the tomographic map. We find an extended IGM overdensity with deep absorption troughs at z = 2.45 associated with a recently discovered galaxy protocluster at the same redshift. Based on simulations matched to our data, we estimate the enclosed dark matter mass within this IGM overdensity to be M dm ( z = 2.45 ) = ( 1.1 ± 0.6 ) × 10 14 h - 1 M ⊙ ?> , and argue based on this mass and absorption strength that it will form at least one z ∼ 0 galaxy cluster with M ( z = 0 ) = ( 3 ± 1.5 ) × 10 14 h - 1 M ⊙ ?> , although its elongated nature suggests that it will likely collapse into two separate clusters. We also point out a compact overdensity of six MOSDEF galaxies at z = 2.30 within a r ∼ 1 h - 1 Mpc ?> radius and Δz ∼ 0.006, which does not appear to have a large associated IGM overdensity. These results demonstrate the potential of Lyα forest tomography on larger volumes to study galaxy properties as a function of environment, as well as revealing the large-scale IGM overdensities associated with protoclusters or other features of large-scale structure.

Hybrid Compact-WENO Finite Difference Scheme with Conjugate Fourier Shock Detection Algorithm for Hyperbolic Conservation Laws

For discontinuous solutions of hyperbolic conservation laws, a hybrid scheme, based on the high order nonlinear characteristicwise weighted essentially nonoscillatory (WENO) conservative finite difference scheme and the high resolution spectral-like linear compact finite difference (Compact) scheme, is developed for capturing shocks and strong gradients accurately and resolving smooth scale structures efficiently. The key issue in any hybrid scheme is the design of an accurate, robust, and efficient high order shock detection algorithm that is capable of determining the smoothness of the solution at any given grid point. The conjugate Fourier (cF) partial sum and its derivative are investigated for its applicability as a shock detector due to its unique property, namely, the cF partial sum converges to the location and strength of an isolated jump. For a nonperiodic problem, the data are first evenly extended before the derivative of the cF partial sum and its mean are computed. The mean allows one to par...

New species of Parachiton (Mollusca: Polyplacophora) from the South China Sea

A new chiton species Parachiton laevisquamatus sp. nov. was described from the southeastern South China Sea. It differs from congeners in having smooth dorsal scales, trapezoidallyshaped intermediate valves in rostral view and a shorter antemucronal area of the tail valve.

Chapala half-graben structure inferred. A magnetometric study

Many geologic and tectonic-structural studies refer to the Chapala lake structure in general terms as a graben (or more generally as rift). However, no formal study has addressed its structure. The Chapala Lake is located in a major topographic depression surrounded by broad middle to late Miocene volcanic-capped plateaus. We conducted a magnetic survey comprising five S-N lines crossing the Chapala Lake. One profile comprises a land extension (southwards along roads). Magnetic anomalies obtained are mainly smooth and large scale features associated to the sedimentary infill, local and high amplitude anomalies are due to shallow basaltic and andesitic tilted blocks, and highest amplitudes due to the outcropped basaltic flows of the Los Alacranes and Mezcala islands. The models obtained point to a large structural high located at the central depression portion that separates two structural lows. The structural lows correspond to half-graben type structures. Through the faults delimiting it were emplaced the basaltic flows of the Mezcala and Los Alacranes islands. The presence of half-graben type structures indicates that the crust has been subject to an extensional tectonic.

Design of stainless steel porous surfaces by oxide reduction with hydrogen

A new method to create porous surfaces on stainless steel by reducing oxide scales with hydrogen at 1100 °C has been investigated. Mercury Intrusion Porosimetry (MIP) along with Scanning Electron Microscopy (SEM) have been used to successfully study the porosity of the surfaces. Two different sets of parameters led to different morphologies. The first type of surface results from a 5 min reduction of a wustite FeO surface oxide layer and provides smooth micrometer scale pores with a Gaussian distribution size. The second type of surface results from a 3 h reduction of a chromium rich oxide layer and provides three different micrometer scale pore size distributions with burst morphology. The volume of the porosity has been compared to its precedent oxide scale volume. The non-stoichiometry of wustite is believed to be the main factor influencing the difference in the pore creation mechanism as compared to the mechanism of reduction from chromium-rich oxide.

A new species of Imantodes Duméril, 1853 (Serpentes, Dipsadidae)from the Eastern Cordillera of Colombia.

We describe a new species of Imantodes, morphologically similar to I. chocoensis, from the Eastern Cordillera of Colombia. This new species is distinguished from all congeners by the following combination of morphological characters: smooth dorsal scale rows 17/17/15; apical pits absent; infralabials 12-13; ventrals 227-236; subcaudals 147-148; presence of loreal scale; cloacal plate divided; dark temporal stripe on the suture between the lower edge of temporal scales and upper region of supralabials; dorsum of body light brown with dark brown transversal streaks, weakly evident in lateral view; hemipenis in situ extending to the level of 11^th subcaudal and reaches the 10^th subcaudal when everted; hemipenis with sulcus spermaticus expanded at the base of capitulum and extending distally. Additionally, we discuss the lateral expansion of the sulcus spermaticus in the new species, similar to that of species of Leptodeira.

A likely microendemic new species of terrestrial iguana, genus Chalarodon, from Madagascar.

A new species of the hitherto monotypic genus Chalarodon is described from southern Madagascar and a lectotype (ZMB 4360) is designated for C. madagascariensis Peters, 1854. The new species of terrestrial iguana, Chalarodon steinkampi sp. nov., is defined by several morphological characters and by concordant differentiation in mitochondrial and nuclear DNA with >5% uncorrected pairwise genetic distance in the 16S rRNA gene. It can be most clearly recognized by the presence of smooth (vs. keeled) gular and ventral scales, a spotted pattern extending from flanks onto belly, and an unpigmented throat. The new species is known from only a small area between the villages of Amboasary Sud and Esomony, located west of the Andohahela Massif, while C. madagascariensis appears to be widespread over much of southern and western Madagascar. We highlight the need for further exploration of this unprotected region which might host several other microendemic species.

Diversity of the snail‐eating snakes Pareas (Serpentes, Pareatidae) from Taiwan

Pareatidae are a group of mollusc‐eating snakes widely distributed in South‐eastern Asia. Due to their dietary specialization, the asymmetric dentition of pareatids has recently become an interesting issue in evolutionary biology. However, phylogenetic relationships and species diversity of pareatids are still poorly studied. A total of three Pareas species, P. formosanus (Van Denburgh 1909), P. compressus (Oshima 1910) and P. komaii (Maki 1931), have been reported for Taiwan. However, only P. formosanus is currently regarded as a valid species. Using mitochondrial sequence phylogeny, nuclear c‐mos haplotype network, as well as multivariate morphometrics, we re‐evaluated the taxonomic status of Pareas from Taiwan, the Ryukyus and adjacent regions. These lines of evidence showed congruent results for the coexistence of three Pareas species in Taiwan, with prominent genetic and morphological differentiation and differing level of dentition asymmetry. The currently used name P. formosanus should be applied only to the snakes with red iris, comparatively short lower jaw and totally smooth dorsal scales. An examination of the type material indicated that the name P. compressus should be regarded as a junior synonym of P. formosensis sensu stricto. Pareas komaii (Oshima 1910) is confirmed as a valid taxon with yellow iris, elongated lower jaw and strongly keeled dorsals. The third clade is characterized by a yellow iris, elongated lower jaw and weakly keeled dorsals. Despite their sympatric occurrence, every examined individual showed consistent grouping from mitochondrial, nuclear and morphological markers, indicating there is no gene flow among these three clades. Here, we describe the third clade as a new specie, Pareas atayal sp. nov.