Tubular channel angular pressing (TCAP) is a recently invented novel severe plastic deformation technique for producing UFG tubes. Plastic deformation analysis using the finite element method (FEM) was carried out to investigate the effects of trapezoidal channel geometry on strain inhomogeneity index (SII), strain level and required load compared to previously used channel geometries. The resu...

In this paper, a moving boundary technique is developed to investigate wave runup and rundown with depth-integratedequations. Highly nonlinear and weakly dispersive equations are solved using a high-order finite difference scheme. An eddyviscosity model is adopted for wave breaking so as to investigate breaking wave runup. The moving boundary technique utilizeslinear extrapolation t...

Trapezoidal words are finite words having at most n+1 distinct factors of length n, for every n≥ 0. They encompass finite Sturmian words. We distinguish trapezoidal words into two disjoint subsets: open and closed trapezoidal words. A trapezoidal word is closed if its longest repeated prefix has exactly two occurrences in the word, the second one being a suffix of the word. Otherwise it is open...

Talbot’s method for the numerical inversion of the Laplace transform consists of numerically integrating the Bromwich integral on a special contour by means of the trapezoidal or midpoint rules. In this paper we address the issue of parameter selection in the method, for the particular situation when parabolic PDEs are solved. In the process the well-known subgeometric convergence rate O(exp(−c...

Methods for aggregating intuitionistic trapezoidal fuzzy information are investigated. Some operational laws of intuitionistic trapezoidal fuzzy numbers are introduced. Based on these operational laws, some aggregation operators, including intuitionistic trapezoidal fuzzy ordered weighted averaging (ITFOWA) operator and intuitionistic trapezoidal fuzzy hybrid aggregation (ITFHA) operator, are p...

We establish relationships between the set of trapezoidal intuitionistic fuzzy numbers and the set of interval-valued trapezoidal fuzzy numbers and, on the other hand, between the set of triangular intuitionistic fuzzy numbers and the set of triangular fuzzy numbers. Based on these main results of the paper, the methods or procedures elaborated for interval-valued trapezoidal or triangular fuzz...

In this paper, stability and error estimates for time discretizations of linear semilinear parabolic equations by the two-step backward differentiation formula (BDF2) method with variable step-sizes are derived. An affirmative answer is provided to question: whether upper bound step-size ratios $l^{\infty }(0,T;H)$ -stability BDF2 identical zero-stability. The }(0,T;V)$ also established under m...

Abstract This study presents an improvement of the graphical method for plotting shear and moment diagrams structural members under linearly varying loads (triangular trapezoidal loads). Based on parabolic nature function, when loading varies linearly, relations among load, shear, moment, a mathematical equation is developed to locate zero-shear point, while geometric technique presented calcul...

trapezoidal channels are frequently used in irrigation networks and other free surface water conveyance systems. the computation of the critical flow depth is one of the primary importance in the design process. it is usually determined by using design charts of iteration techniques. however, researchers have recently proposed formulas that directly provide approximate solutions. this paper pre...

In some multi-attribute decision making (MADM) problems, various relationships among the decision attributes should be considered. This paper investigates the prioritization relationship of attributes in MADM with trapezoidal intuitionistic fuzzy numbers (TrIFNs). TrIFNs are a special intuitionistic fuzzy set on a real number set and have the better capability to model ill-known quantities. Fir...