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A general method of element testing is presented. The method applies to any shape of element with any number of nodes. The shape parameters for a quadrilateral are shown to be contained within the Jacobian matrix and it is also shown that the determinant of this matrix can be expressed in terms of the shape parameters.

The purpose of this paper is to analyze the suitability of the real option methods in the valuation of WiMAX networks. Particularly, the shapes of the probability distributions for the investment costs and net present values (NPV) are examined.

The study analyzes the costs and NPV distributions by simulating an investment project in a rural area. The paper examines the influences of different uncertainty models and the shapes of the resulting investment costs, NPVs, and NPV ratios. The simulated option values are compared to results from different analytical equations.

The analysis in this study shows that the shape of the uncertainty – or error – in the parameters does not affect the shapes of the investment costs or NPV distribution. Instead, the subject of the uncertainty – i.e. the parameters for which the uncertainty is modeled – matters.

The study shows that the uncertainties and opportunities in network investments may increase the value of the projects dramatically and thus they should be taken into account. The shape of the NPV distribution varies depending on the technology and construction strategy of the network. This makes the real option valuation challenging since the assumptions of the valuation models must be satisfied for reliable results. Analytical option valuation formulas give the same results as simulation, only if the assumptions are sufficiently fulfilled and the parameters properly estimated.

The uncertainty in the service rate growth or population growth parameter influences the resulting distributions. The investment costs are positively skewed and can be approximated by a log‐normal distribution. This makes NPV negatively skewed, which suits badly in the existing analytical option valuation methods assuming log‐normal assets. Also, the NPV ratio is correlated with the investment costs.

This study focused on how to quantify the similarities of body shape based on the front and side images, and a shape comprehensive index (I_SC) of female upper body shape based on 2D images was proposed.

In total, 190 young women were shot for front and side images, and 18 shape parameters were automatically extracted, including seven angles and 11 ratio parameters. The coefficient of variation method was used to assign different weights for related parameters, and the I_SC was calculated to describe the body shape of each subject. Five cross-sectional curves of the upper body (e.g. shoulder, chest, waist, abdomen and hip) were selected for exploring the range of shape similarity.

According to the value of I_SC, if the difference among the subjects is within the range of ±0.02, their body shapes can be regarded as similar, and the subject with the minimum distance is considered as the most similar. Error results show that the error range of the angle parameter is from 0.2° to 3.6° and the ratio range is from 0.001 to 0.119. Moreover, the t-test value among the parameters of the similar body is above 0.05, indicating that there is no significant difference for the upper body shape of the similar groups.

This method can quantify body shapes with the upper body characteristics of young women instead of subjective judgment. The study can be extended to other parts of the body and can also provide a new thought for shape similarity retrieval based on 2D images.

Focuses on the inverse problems arising from the simulation of forming processes. Considers two sets of problems: parameter identification and shape optimization. Both are solved using an optimization method for the minimization of a suitable objective function. The convergence and convergence rate of the method depend on the accuracy of the derivatives of this function. The sensitivity analysis is based on a discrete approach, e.g. the differentiation of the discrete problem equations. Describes the method for non‐linear, non‐steady‐state‐forming problems involving contact evolution. First, it is applied to the parameter identification and to the torsion test. It shows good convergence properties and proves to be very efficient for the identification of the material behaviour. Then, it is applied to the tool shape optimization in forging for a two‐step process. A few iterations of the inverse method make it possible to suggest a suitable shape for the preforming tools.

Since most of the existing literature do not disclose the node coordinate data of its fixed-wing aircraft airfoil, in order to develop and obtain a practical and suitable deformation airfoil for fixed-wing micro air vehicle (MAV), this paper proposes an improved airfoil design method of fixed-wing MAV based on the profile data of S5010 airfoil.

Combined with the body shape variation of the stingray in the propulsion process, the parametric study of the aerodynamic shape of the original design airfoil is carried out to explore the influence of a single parameter change on the aerodynamic performance of the airfoil. Then, according to the influence law of single parameter variation on the aerodynamic performance of the airfoil, the original airfoil is synthetically deformed by changing multiple parameters.

By comparing the aerodynamic performance of the multi-parameter deformed airfoil with the original airfoil, it is found that the lift coefficient of the multi-parameter deformed airfoil changes from negative to positive value when AOA = 0°. When AOA = 2°, the lift coefficient growth rate is the largest, which is 47.27%, and the lift-to-drag ratio is increased by 50.00%. At other angles of attack, the lift, drag, and torque coefficients of the multi-parameter deformed airfoil are optimized to some extent.

Combined the body shape variation of the stingray in the propulsion process, the parametric study of the aerodynamic shape of the original design airfoil is carried out to explore the influence of a single parameter change on the aerodynamic performance of the airfoil.

This paper reviews the pros and cons of different parametric modeling methods, which can provide a theoretical reference for parametric reconstruction of 3D human body models for virtual fitting.

In this study, we briefly analyze the mainstream datasets of models of the human body used in the area to provide a foundation for parametric methods of such reconstruction. We then analyze and compare parametric methods of reconstruction based on their use of the following forms of input data: point cloud data, image contours, sizes of features and points representing the joints. Finally, we summarize the advantages and problems of each method as well as the current challenges to the use of parametric modeling in virtual fitting and the opportunities provided by it.

Considering the aspects of integrity and accurate of representations of the shape and posture of the body, and the efficiency of the calculation of the requisite parameters, the reconstruction method of human body by integrating orthogonal image contour morphological features, multifeature size constraints and joint point positioning can better represent human body shape, posture and personalized feature size and has higher research value.

This article obtains a research thinking for reconstructing a 3D model for virtual fitting that is based on three kinds of data, which is helpful for establishing personalized and high-precision human body models.

This study aims at proposing an approach for optimizing the shape of the top piston ring face for minimum friction force using an inverse method. The shape of the top piston ring face determines the amount of oil distribution in the interface of the ring and liner. Therefore, the shape has a significant impact on the tribological performance of this interface.

The shape of the ring face is represented by a polynomial function and is based on the load analysis of the ring. The optimization of the shape was performed using the Sequential Quadratic Programming method. The minimizing of the friction parameter at the interface was considered during the solving process to obtain an optimum ring shape.

The optimized high degree of the shape of the ring face could lead to a reduced friction parameter. The proposed method could be applied for the tribological design and optimization of the piston rings.

There still need effort to investigate the effect of design parameters (e.g. property of lubricant)on the optimization of the ring face.

The subject matter is important and the method has practical value.

The purpose of this paper is to upgrade our previous developments of Local Radial Basis Function Collocation Method (LRBFCM) for heat transfer, fluid flow and electromagnetic problems to thermoelastic problems and to study its numerical performance with the aim to build a multiphysics meshless computing environment based on LRBFCM.

Linear thermoelastic problems for homogenous isotropic body in two dimensions are considered. The stationary stress equilibrium equation is written in terms of deformation field. The domain and boundary can be discretized with arbitrary positioned nodes where the solution is sought. Each of the nodes has its influence domain, encompassing at least six neighboring nodes. The unknown displacement field is collocated on local influence domain nodes with shape functions that consist of a linear combination of multiquadric radial basis functions and monomials. The boundary conditions are analytically satisfied on the influence domains which contain boundary points. The action of the stationary stress equilibrium equation on the constructed interpolation results in a sparse system of linear equations for solution of the displacement field.

The performance of the method is demonstrated on three numerical examples: bending of a square, thermal expansion of a square and thermal expansion of a thick cylinder. Error is observed to be composed of two contributions, one proportional to a power of internodal spacing and the other to a power of the shape parameter. The latter term is the reason for the observed accuracy saturation, while the former term describes the order of convergence. The explanation of the observed error is given for the smallest number of collocation points (six) used in local domain of influence. The observed error behavior is explained by considering the Taylor series expansion of the interpolant. The method can achieve high accuracy and performs well for the examples considered.

The method can at the present cope with linear thermoelasticity. Other, more complicated material behavior (visco-plasticity for example), will be tackled in one of our future publications.

LRBFCM has been developed for thermoelasticity and its error behavior studied. A robust way of controlling the error was devised from consideration of the condition number. The performance of the method has been demonstrated for a large number of the nodes and on uniform and non-uniform node arrangements.

The purpose of this paper is to study the thermal behaviour of radial porous fin wetted with nanofluid containing different shaped nanoparticles in the presence of natural convection and radiation. Here, the nanofluid suspended with molybdenum disulfide nanoparticle with base fluid as water is considered. The influence of non-spherical nanoparticles such as platelet, cylinder, brick and blade shapes is also investigated.

The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme.

The flow natures of the pertinent parameter are represented graphically and discussed their physical significance. From the validation of obtained outcome, it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.

The present paper deals with an analysis of the flow of molybdenum disulfide nanoparticles suspended in water over a porous fin of a radial profile. The effect of differently shaped nanoparticles on the heat transfer enhancement through the radial porous fin is investigated for the first time. The natural convection and radiation effects are also considered. The modeled equations are non-dimensionalized and solved numerically via Runge–Kutta–Fehlberg method combined with shooting scheme. The effect of pertinent parameters on temperature field is examined. From the validation of obtained outcome it is found that the use nanofluid has significant influence on heat transfer rate. Among platelet, cylinder, brick and blade shapes, brick-shaped nanoparticle shows better heat transfer rate.

This research aims to present the characteristics of dimple structure which was fabricated using a turning machine, where the characteristics include sizes, shapes, area ratio and aspect ratio. This research aims at filling the gap in the machining parameters of previous research in producing dimple by using turning process with the aid of dynamic assisted tooling for turning (DATT). In producing dimple, a carbide insert grade H1 was used on a hypereutectic aluminium silicon alloy (A390) material. Dimple has many advantages such as for reducing friction coefficient, load-carrying capacity and trap wear debris for sliding mechanical components.

There are seven machining parameters (cutting speed, feed rate, depth of cut, frequency, amplitude, rake angle, relief angle and nose radius) which have an influence on dimple produced. Taguchi method (orthogonal arrays L8) was used to conduct the experiment systematically and efficiently for these seven parameters. A carbide insert grade H1 was used as a cutting tool on a turning machine with the aid of DATT. The dimple structure was fabricated on a cylindrical rod hypereutectic aluminium silicon alloy (A390). A profilometer 3D Alicona infinite focus and an optical microscope equipped with Vis software were used to analyse the fabricated dimple structure.

Various shapes and sizes of ellipse dimples were produced in this research, including short and long drops with lengths in the range of 517.03–3,927.61 µm, widths of 565.15–1,039.19 µm, depths of 14.46–124.87 µm, area ratios of 5.05–25.65% and aspect ratios of 0.007%–0.111%. There were four experiments within the optimal area ratio range of 10%–20%, i.e. the second, third, seventh and eighth experiments. The width of these dimples was 895.95, 961.39, 787.27 and 829.22 µm, length was 826.26, 3163.13, 885.98 and 1026.65 µm, depth was 83.67, 84.19, 87.05 and 110.70 µm and area ratio was 15.12%, 13.14%, 14.79% and 12.70%. The surface roughness of textured surface was below 1 µm. In this research, the results obtained were similar with that of previous researchers on dimple structure related to tribology performance.

There exists machining parameters, namely, cutting speed and frequency, that were not used by previous research in producing dimple. These machining parameters (cutting speed and frequency) were used in this research to produce dimple via turning process with the aid of DATT using carbide insert grade H1. The turning process is an environmentally friendly process which is suitable for mass production for fabricating dimple structure as compared to most of the current methods which are widely used in fabricating dimple structure.