Order Terms Research Articles

A nodal integration based two level local projection meshfree stabilization method for convection diffusion problems

This paper presents a new two level local projection meshfree stabilization (LPMS) method under the classical stabilized conforming nodal integration (SCNI) framework to solve convection diffusion problems suitable to a linear order approximation. Dropping the higher order terms in the residual based Petrov-Galerkin stabilization methods, usual in the Gauss integration, produces erroneous results if the classical SCNI is used because of the product of a quantity and its smoothed gradient (SCNI divergence operator) in the convective term. LPMS method is an alternative way to achieve a stable solution with the linear order approximation. In the present method, the design of the stabilization of convective terms stems from the fine scales defined on the subcells of Voronoi cells of SCNI. This LPMS with SCNI combination excludes the computational need for derivatives. First order mesh basis functions are sufficient as the SCNI replaces lower order derivatives with smoothed gradients, while local projection stabilization (LPS) excludes the terms with higher order derivatives. The present LMPS method is tested against standard benchmark problems with different distorted grids and compared with three existing stabilization methods. It is found to be in good agreement with the classical numerical methods for problems with thin layers.

To the scrutiny of the experiential and computational elicitation of factors of the Williams multi-parameter expansion

The article defines stress fields near the tips of mathematical cracks in an isotropic linearly elastic plate with two horizontal collinear cracks lying on a straight line of different lengths under the uniaxial tensile condition, using two approaches - experimental, based on the method of digital photomechanics, and numerical, based on finite element calculations. To represent the stress field at the tip of the section, the Williams polynomial series is used - the canonical representation of the field at the top of the mathematical section of a two-dimensional problem of elasticity theory for isotropic media. The main idea of the current study is to take into consideration the regular (non-singular) terms of the series and analyze their impact on the holistic description of the stress field in the immediate vicinity of the top of the section. The first fifteen coefficients of the Max Williams series were preserved and determined in accordance with experimental patterns of isochromatic bands and finite element modeling. To extract the coefficients of the Williams series used a redefined method designed to solve systems of algebraic equations, the number of which is significantly greater than the unknown - amplitude multipliers. The influence of the non-singular terms of the Williams series on the processing of the experimental pattern of interference fringes is demonstrated. It is validated that the preservation of the terms of a high order of smallness makes it possible to expand the area adjacent to the tip of the crack, from which experimental points can be selected. The finite element study was carried out in the SIMULIA Abaqus engineering analysis system, in which experimental samples tested in a full-scale experiment were reproduced. It is revealed that the results obtained by the two methods are in good agreement with each other.

Event‐triggered finite‐time control for a constrained robotic manipulator with flexible joints

AbstractIn the article, an event‐triggered control policy is developed for a robotic manipulator with flexible joint (RMFJ) in the presence of finite‐time convergence under the requirement of output constraints. Due to the vibration existing in the flexible joint, compared with the rigid manipulator, it is exceedingly difficult for RMFJ to design an adaptive method for realizing highly accurate control. In order to reduce and restrain the vibration of the flexible joint, a finite‐time convergence policy is designed by introducing the fractional order term. Moreover, the angular displacements of the link are constrained in the predefined region by using the Barrier function, which further enhances the operation safety. Neural networks learning is used to approximate unknown model parameters. Event‐trigger design is used to reduce the communication burden.

Local well-posedness of the free-boundary problem in compressible resistive magnetohydrodynamics

We prove the local well-posedness in Sobolev spaces of the free-boundary problem for compressible inviscid resistive isentropic MHD system under the Rayleigh-Taylor physical sign condition, which describes the motion of a free-boundary compressible plasma in an electro-magnetic field with magnetic diffusion. We use Lagrangian coordinates and apply the tangential smoothing method introduced by Coutand-Shkoller to construct the approximation solutions. One of the key observations is that the Christodoulou-Lindblad type elliptic estimate together with magnetic diffusion not only gives the common control of magnetic field and fluid pressure directly, but also controls the Lorentz force which is a higher order term in the energy functional.

Minimal lensing solutions in the singular perturbative approach

ABSTRACT This paper analyses the properties of minimal solutions for the reconstruction of the lens potential in the singular perturbative approach. These minimal solutions corresponds to an expansion with a minimal degree in Fourier expansion of the perturbative fields. Using these minimal solutions prevent spurious physically meaningless terms in the reconstruction of the fields. In effect, a perturbative analysis indicates that a small change in the source model will corresponds to the higher order terms in the expansion of the fields. The results of the perturbative analysis are valid not only for slightly non-circular sources but also for more distorted sources to order two. It is, thus, of crucial importance to minimize the number of terms used in the modelling of the lens. Another important asset of the minimal solutions is that they offer a de-coupling between the source and lens model, and thus help to break the source lens degeneracy issue. The possible drawback of minimal solutions is to underestimate the higher order terms in the solution. However, this bias has its merit since the detection of higher order terms using this method will ensure that these terms are real. This type of analysis using minimal solutions will be of particular interest when considering the statistical analysis of a large number of lenses, especially in light of the incoming satellite surveys.

Plant mitochondrial introns as genetic markers - conservation and variation.

Plant genomes are comprised of nuclear, plastid and mitochondrial components characterized by different patterns of inheritance and evolution. Genetic markers from the three genomes provide complementary tools for investigations of inheritance, genetic relationships and phenotypic contributions. Plant mitochondrial genomes are challenging for universal marker development because they are highly variable in terms of size, gene order and intergenic sequences and highly conserved with respect to protein-coding sequences. PCR amplification of introns with primers that anneal to conserved, flanking exons is effective for the development of polymorphic nuclear genome markers. The potential for plant mitochondrial intron polymorphisms to distinguish between congeneric species or intraspecific varieties has not been systematically investigated and is possibly constrained by requirements for intron secondary structure and interactions with co-evolved organelle intron splicing factors. To explore the potential for broadly applicable plant mitochondrial intron markers, PCR primer sets based upon conserved sequences flanking 11 introns common to seven angiosperm species were tested across a range of plant orders. PCR-amplified introns were screened for indel polymorphisms among a group of cross-compatible Citrus species and relatives; two Raphanus sativus mitotypes; representatives of the two Phaseolus vulgaris gene pools; and congeneric pairs of Cynodon, Cenchrus, Solanum, and Vaccinium species. All introns were successfully amplified from each plant entry. Length polymorphisms distinguishable by gel electrophoresis were common among genera but infrequent within genera. Sequencing of three introns amplified from 16 entries identified additional short indel polymorphisms and nucleotide substitutions that separated Citrus, Cynodon, Cenchrus and Vaccinium congeners, but failed to distinguish Solanum congeners or representatives of the Phaseolus vulgaris major gene pools. The ability of primer sets to amplify a wider range of plant species' introns and the presence of intron polymorphisms that distinguish congeners was confirmed by in silico analysis. While mitochondrial intron variation is limited in comparison to nuclear introns, these exon-based primer sets provide robust tools for the amplification of mitochondrial introns across a wide range of plant species wherein useful polymorphisms can be identified.

Cumulants from short-range correlations and baryon number conservation at next-to-leading order

We calculate the baryon number cumulants within acceptance with short-range correlations and global baryon number conservation in terms of cumulants in the whole system without baryon conservation. We extract leading and next-to-leading order terms of the large baryon number limit approximation. Our results extend the findings of Refs. [1,2]. These approximations are checked to be very close to the exact results.

Parity Quantum Optimization: Benchmarks

We present benchmarks of the parity transformation for the Quantum Approximate Optimization Algorithm (QAOA). We analyse the gate resources required to implement a single QAOA cycle for real-world scenarios. In particular, we consider random spin models with higher order terms, as well as the problems of predicting financial crashes and finding the ground states of electronic structure Hamiltonians. For the spin models studied our findings imply a significant advantage of the parity mapping compared to the standard gate model. In combination with full parallelizability of gates this has the potential to boost the race for demonstrating quantum advantage.

Quasielastic (p, n) reactions described by a microscopic optical model based on the Gogny force

In this work, we want to study quasielastic (p, n) exchange reactions using a semi-microscopic optical model derived from a previous work, Lopez Moraña and Viñas (2021 J. Phys. G48 035104) based on a nuclear matter approach where the real and imaginary parts are given by the first and second order terms, respectively, of the mass operator obtained by a Brueckner–Hartree–Fock calculation using a G-matrix built up with an effective Gogny interaction. The study of these quasielastic reactions is performed within a Distorted Wave Born Approximation to evaluate the wave functions in the entrance and exit channels, which in turn are used to compute the transition matrix elements. This model, which is free of adjustable parameters, provides a reasonably good agreement with the considered experimental data, namely differential cross sections, analyzing powers and total cross sections, of different reactions spanned along the periodic table at several energies.

Perturbations of general relativity to all orders and the general nth order terms

We derive all-order expressions for perturbations of the Einstein-Hilbert action and the Einstein equation with the general n-th order terms. To this end, we employ Cheung and Remmen’s perturbation conventions both in tensor density and the usual metric tensor formalisms, including the Einstein-dilaton theory. Remarkably, we find minimal building blocks that generate the entire perturbations for each of our formulations. We show that the number of terms of perturbations grows linearly as the order of perturbations increases. We regard our results as the reference and discuss how to derive perturbations in other conventions from the reference. As a consistency check, we compute graviton scattering amplitudes using the perturbiner method based on the perturbative Einstein equation. Finally we discuss how to generalise the results to curved backgrounds and incorporate additional matter.

On the Harnack inequality for antisymmetric s-harmonic functions

We prove the Harnack inequality for antisymmetric s-harmonic functions, and more generally for solutions of fractional equations with zero-th order terms, in a general domain. This may be used in conjunction with the method of moving planes to obtain quantitative stability results for symmetry and overdetermined problems for semilinear equations driven by the fractional Laplacian.The proof is split into two parts: an interior Harnack inequality away from the plane of symmetry, and a boundary Harnack inequality close to the plane of symmetry. We prove these results by first establishing the weak Harnack inequality for super-solutions and local boundedness for sub-solutions in both the interior and boundary case.En passant, we also obtain a new mean value formula for antisymmetric s-harmonic functions.

High-order Coverage of Smoothed Bayesian Bootstrap Intervals for Population Quantiles

We characterize the high-order coverage accuracy of smoothed and unsmoothed Bayesian bootstrap confidence intervals for population quantiles. Although the original (Rubin 1981) unsmoothed intervals have the same O(n−1/2) coverage error as the standard empirical bootstrap, the smoothed Bayesian bootstrap of Banks (1988) has much smaller O(n−3/2[log(n)]3) coverage error and is exact in special cases, without requiring any smoothing parameter. It automatically removes an error term of order 1/n that other approaches need to explicitly correct for. This motivates further study of the smoothed Bayesian bootstrap in more complex settings and models.

Investigating the Dynamics of Time-Fractional Drinfeld–Sokolov–Wilson System through Analytical Solutions

This study addresses a nonlinear fractional Drinfeld–Sokolov–Wilson problem in dispersive water waves, which requires appropriate numerical techniques to obtain an approximative solution. The Adomian decomposition approach, the homotopy perturbation method, and Sumudu transform are combined to tackle the problem. The Caputo manner is used to describe fractional derivative, and He’s polynomials and Adomian polynomials are employed to address nonlinearity. By following these approaches, we obtain solutions in the form of convergent series. We verify and demonstrate the effectiveness of our suggested strategies by examining the assumed model in terms of fractional order. We use plots for various fractional orders to represent the physical behavior of the suggested technique solutions, and show a numerical simulation. The results demonstrate that the suggested algorithms are systematic, simple to use, effective, and accurate in analyzing the behavior of coupled nonlinear differential equations of fractional order in related scientific and engineering fields.

A Pragmatic Study of Dysphemism in Steven Berkoff’s Play East

The present study pragmatically explores categories and functions of dysphemisms in Steven Berkoff’s play East. The objective of the paper is to explore the characters’ use of dysphemism; its categories and functions and apply Allan and Burridge’s (2006) classification of dysphemism, Goffman’s (1962) notion of face, and Brown and Levinson’s (1987) theory of politeness to the play. To gather and examine the text, the researcher adopts a qualitative descriptive approach which involves the researcher himself being the instrument who does everything. The data are taken from the script that is read and re-read to identify the dysphemistic expressions and then coded to be analyzed by using a qualitative discourse analysis method. The results of the paper reveal that all characters use all the categories of dysphemism; insult is the most used followed by profanity and obscenity. In addition, they utilize dysphemism to express hatred, anger, and disrespect, ridicule, and insult each other. Besides, they do not mitigate their expressions and attack each other positive face and the audience’s positive face too. The findings of the study are beneficial to pupils, teachers, writers, journalists, TV producers, footballers, orators, filmmakers, and politicians who are anticipated to be familiar with the dysphemistic terms in order to avoid them and use neutral ones as alternatives.

Current evidence on loop length in intestinal bypass procedures

Intestinal bypass procedures are well recognized for their long-term weight reduction and control of metabolic comorbidities. The selection of the length of the small bowel loop has a significant influence on the positive and also negative effects of the chosen procedure but national and international standardization are missing. The aim of this article is to give an overview of the current evidence on the various intestinal bypass procedures and the influence of the chosen small bowel loop length on the desired and adverse postoperative outcomes. The IFSO 2019 consensus recommendations on the standardization of bariatric surgery and metabolic procedures form the basis of these considerations. The current literature was searched for comparative studies addressing the question of different small bowel loop lengths in a Roux-en‑Y gastric bypass, one anastomosis gastric bypass, single anastomosis duodenoileal bypass with sleeve gastrectomy and biliopancreatic diversion (with duodenal switch). Due to the heterogeneity of currently available studies and interindividual differences in total small bowel lengths in humans, it is difficult to give definitive recommendations for the choice of small bowel loop lengths. The longer the biliopancreatic loop (BPL) or the shorter the common channel (CC), the higher is the risk of (severe) malnutrition. To prevent malnutrition, the BPL should not be longer than 200 cm and the CC should have alength of at least 200 cm. The intestinal bypass procedures recommended in the German S3 guidelines are safe and show good long-term outcomes. As part of the postbariatric follow-up, the nutritional status of patients following an intestinal bypass has to be followed-up on the long term in order to avoid malnutrition preferably prior to aclinical manifestation.

Complex Queries for Querying Linked Data

Querying Linked Data is one of the most important issues for the semantic web community today because it requires the user to understand the structure and vocabularies used in various data sources. Furthermore, users must be familiar with the syntax of query languages, such as SPARQL. However, because users are accustomed to natural language-based search, novice users may find it challenging to use these features. As a result, new approaches for querying Linked Data sources on the web with NL queries must be defined. In this paper, we propose a novel system for converting natural language queries into SPARQL queries to query linked and heterogeneous semantic data on the web. While most existing methods have focused on simple queries and have ignored complex queries, the method described in this work aims to handle various types of NL queries, particularly complex queries containing negation, numbers, superlatives, and comparative adjectives. Three complementary strategies are used in this context: (1) identifying the semantic relations between query terms in order to understand the user’s needs; (2) mapping the NL terms to semantic entities; and (3) constructing the query’s valid triples based on the different links used to describe the identified entities in order to generate correct SPARQL queries. The empirical evaluations show that the proposed system is effective.

‘It is the greenness, the nature, it looks as if someone has taken care of the place very well’

This article is about experiences of a cemetery landscape: a physical space that was chosen as a depository for human remains, and where different memorial and disposal practices have developed behavioural patterns that together form a cemetery culture. Through qualitative research at St Eskil’s, Eskilstuna, Sweden, encompassing field observations and interviews (N=14) with stakeholders and people from the general public, we aim to describe and discuss the cemetery as a place and environment experienced from a perspective of people of diverse backgrounds. The study reveals important characteristics that facilitate designing, caretaking, developing and using cemeteries more generally. Findings show that most interviewees, independent for example of cultural or religious adherence, describe the cemetery as a beautiful natural or garden-like place. The well-maintained landscape is emphasized as a self-evident or impressive quality. The cemetery is experienced as ‘typically Swedish’ and described in terms of order and sense of care. Diversity in both design and multi-cultural and individual expressions are observed, acknowledged and welcomed. We conclude that nature (including a garden approach), care and diversity are key concepts that should be considered in design and development of future cemeteries.

Quasi-topological gravities on general spherically symmetric metric

In this work we study a more restricted class of quasi-topological gravity theories where the higher curvature terms have no contribution to the equation of motion on general static spherically symmetric metric where gttgrr ≠ constant. We construct such theories up to quintic order in Riemann tensor and observe an important property of these theories: the higher order term in the Lagrangian vanishes identically when evaluated on the most general non-stationary spherically symmetric metric ansatz. This not only signals the higher terms could only have non-trivial effects when considering perturbations, but also makes the theories quasi-topological on a much wider range of metrics. As an example of the holographic effects of such theories, we consider a general Einstein-scalar theory and calculate it’s holographic shear viscosity.

Optical Solitons and traveling wave solutions to Kudryashov’s equation

This paper employs a generalized transformation to investigate Kudryashov’s equation with four nonlinear terms in order to construct traveling wave solutions and optical solitons. The proposed unified ansätze framework is manipulated to derive analytical solutions, which are expressed as a combination of general solutions to simpler equations or systems of equations that are integrable or have unique known solutions. Using this technique, one can produce families of new exact solutions as well as solitary solutions. In addition to other model solutions, the scheme reveals the elliptic functions of Jacobi, Weierstrass, and Riccati. These are categorized as singular, bright, and dark optical solitons.

Bullwhip effect in closed-loop supply chains with multiple reverse flows: a simulation study

Due to the complex nature of some products and the different quality of returns, in closed-loop supply chains there might be different types of reverse processes and reverse flows, including repaired, refurbished, remanufactured, or recycled goods. These reprocessed goods return to different echelons of the supply chain according to their quality, and the volume of each type of reverse flow (i.e. the returns share) may significantly vary between different supply chains, affecting the dynamic behaviour of the entire system. The aim of this work is to explore the impact of the volume of returns among multiple reverse flows in a closed-loop supply chain where each member can have its own reverse flow. We analyse a four-echelon closed-loop supply chain, where a collector is in charge of collecting and inspecting the returns and sending them to the different echelons depending on their quality. An agent-based simulation model considering different return rates, coefficient of variations for the forward lead times, and returns share is developed and evaluated in terms of bullwhip effect. We observe that considerable volume and medium–low quality of the returns enable bullwhip effect reduction in systems where returns are shared among all the members of the supply chain. However, in single reverse flow closed-loop supply chains, moderate volume and high quality of the returns are preferable to gain improvements both in terms of order and inventory variability. From a managerial point of view, we provide useful recommendations for companies adopting closed-loop.