Munish Kumar¹, Simpel Rani Jindal²

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.2, pp. 195-202, 2017, DOI:10.3970/cmes.2017.113.201

Abstract Grading of writers in perspective of their handwriting is a challenging task owing to various writing styles of different individuals. This paper presents a framework for grading of Devanagari writers in perspective of their handwriting. This framework of grading can be useful in conducting the handwriting competitions and then deciding the winners on the basis of an automated process. Selecting the set of features is a challenging task for implementing a handwriting grading system of particular language. In this paper, curvature features, namely, parabola curve fitting and power curve fitting have been considered for extracting the vital information of writers,… More >

Tengfei Sun¹, Deli Gao^1,2, Hui Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.1, pp. 37-46, 2013, DOI:10.3970/cmes.2013.090.037

Abstract Well profile design is one of the critical technologies in extended reach drilling (ERD), because an optimum well profile is an effective means for reducing the torque, drag and cost. This paper proposes a new well profile based on an inverse proportional function, and the new profile design method is analyzed in detail. The new well profile is also compared with other existing well profiles in many aspects such as the hook load, the maximum well curvature, the well length, the torque and so on. The results show that the well profile design based on an inverse proportional curve is… More >

P.D.Gosling¹, L. Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.2, pp. 97-142, 2012, DOI:10.32604/cmes.2012.083.097

Abstract The analysis of membrane structures is made complex by the essentially anti-clastic geometry and flexibility introducing significant geometric non-linearities. With the increasing application of these structures in high-profile projects, the introduction of new materials in the form of ETFE foil, for example, and the impending requirements of a membrane structures-specific Eurocode, the need for high quality analysis capabilities is paramount. Existing formulations lag behind shell element counterparts and are based on a range of principles, from discrete to continua, and uniaxial to plane stress constitutive laws. In this paper, we present a linear strain triangular element for the efficient and… More >

H.F.Qiang¹, F.Z.Chen¹, W.R. Gao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.3&4, pp. 239-262, 2011, DOI:10.3970/cmes.2011.077.239

Abstract Based on smoothed particle hydrodynamics (SPH) method with surface tension proposed by Morris, this paper is intended to modify equations for surface tension by modifying normal and curvature with corrective smoothing particle method (CSPM). Compared with the continuum surface force (CSF) model for surface tension employed in the traditional SPH method, the accuracy in the present paper is much higher in terms of handling the problems with large deformation and surface tension. The reason is that in the traditional SPH method the deficiency of particles is near the boundary and sharp-angled areas, and it causes gross errors of curvature calculation.… More >

V. Ungvichian¹, P. Kanongchaiyos¹

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.3&4, pp. 201-220, 2011, DOI:10.3970/cmes.2011.077.201

Abstract This paper describes an enhancement to Garland and Heckbert's mesh simplification method by using the principal curvatures and directions of each vertex. We calculate the values and directions, before using them to determine the absolute normal curvature in the direction of contraction, and multiplying the curvature with the edge length, the maximum absolute cosine of the angles between the edge and the normals of faces adjacent to either endpoint, and the quadric error of the collapse. We also apply penalties based on compactness and angular and dihedral deviations of the resulting faces. We have implemented these improvements and tested our… More >

Francisco P. M. Oliveira¹, João Manuel R. S. Tavares¹

CMES-Computer Modeling in Engineering & Sciences, Vol.43, No.1, pp. 91-110, 2009, DOI:10.3970/cmes.2009.043.091

Abstract This paper presents a new methodology to establish the best global match of objects' contours in images. The first step is the extraction of the sets of ordered points that define the objects' contours. Then, by using the curvature value and its distance to the corresponded centroid for each point, an affinity matrix is built. This matrix contains information of the cost for all possible matches between the two sets of ordered points. Then, to determine the desired one-to-one global matching, an assignment algorithm based on dynamic programming is used. This algorithm establishes the global matching of the minimum global… More >

Michael Yu Wang¹, Xiaoming Wang²

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.4, pp. 373-396, 2004, DOI:10.3970/cmes.2004.006.373

Abstract This paper addresses the problem of structural shape and topology optimization. A level set method is adopted as an alternative approach to the popular homogenization based methods. The paper focuses on four areas of discussion: (1) The level-set model of the structure’s shape is characterized as a region and global representation; the shape boundary is embedded in a higher-dimensional scalar function as its “iso-surface.” Changes of the shape and topology are governed by a partial differential equation (PDE). (2) The velocity vector of the Hamilton-Jacobi PDE is shown to be naturally related to the shape derivative from the classical shape… More >

D. Zupan¹, M. Saje¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.2, pp. 301-318, 2003, DOI:10.3970/cmes.2003.004.301

Abstract A new finite element formulation of the `kinematically exact finite-strain beam theory' is presented. The finite element formulation employs the generalized virtual work in which the main role is played by the pseudo-curvature vector. The solution of the governing equations is found by using a combined Galerkin-collocation algorithm. More >

K. S. Alan¹

CMC-Computers, Materials & Continua, Vol.44, No.1, pp. 1-21, 2014, DOI:10.3970/cmc.2014.044.001

Abstract In the framework of the piecewise homogeneous body model with the use of the three-dimensional geometrically nonlinear exact equations of the theory of elasticity, the method developed for the determination of the stress distribution in the nanocomposites with unidirectional locally curved and hollow nanofibers is used to investigate the normal stresses acting along the nanofibers. Furthermore, it is assumed that the body is loaded at infinity by uniformly distributed normal forces which act along the nanofibers and the crosssection of the nanofibers and normal to its axial line, is a circle of constant radius along the entire nanofiber length. For… More >

Sen-Yung Lee¹, Shueei-Muh Lin^2,3, Kai-Ping Chang¹

CMC-Computers, Materials & Continua, Vol.51, No.1, pp. 1-19, 2016, DOI:10.3970/cmc.2016.051.001

Abstract The two coupled governing differential equations for the out-of-plane vibrations of non-uniform beams with variable curvature are derived via the Hamilton's principle. These equations are expressed in terms of flexural and torsional displacements simultaneously. In this study, the analytical method is proposed. Firstly, two physical parameters are introduced to simplify the analysis. One derives the explicit relations between the flexural and the torsional displacements which can also be used to reduce the difficulty in experimental measurements. Based on the relation, the two governing characteristic differential equations with variable coefficients can be uncoupled into a sixth-order ordinary differential equation in terms… More >