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Sulaiman M.N.I.,University of Technology Malaysia | Choo Y.-H.,University of Technology Malaysia | Chong K.E.,Technical University of Malaysia
Conference on Data Mining and Optimization | Year: 2011

This work presents an approach based on the ant colony optimization technique to address the assembly line balancing problem. An improved ant colony optimization with look forward ant is proposed to solve the simple assembly line balancing problem of type 1 (SALBP-1). The proposed algorithm introduces an approach to dynamically assign the value of priority rule or heuristic information during the task selection phase by allowing the ant to look forward its direct successors during the consideration in selecting a task to be assigned into a workstation. The proposed algorithm is tested and compared with literature data sets and the result from the proposed algorithm shows competitive performance against them. © 2011 IEEE. Source

Winkler R.,Aalen University of Applied Sciences | Pannert W.,Aalen University of Applied Sciences | Merkel M.,Aalen University of Applied Sciences | Ochsner A.,Technical University of Malaysia
Materialwissenschaft und Werkstofftechnik | Year: 2011

Metallic hollow sphere structures (MHSS) form a relatively new group of advanced composite materials characterised by high geometry reproduction leading to stable mechanical and physical properties. The MHSS combine the well-known advantages of cellular metals in terms of their high ability for energy adsorption, good damping behaviour, excellent heat insulation and high specific stiffness without major scattering of their material parameters. A combination of these properties opens a wide field of potential applications, e. g. in automotive (crash absorber) and aerospace industry (sandwich panels). Various joining technologies such as sintering, soldering and adhering can be used to assemble single metallic hollow spheres to interdependent structures and allow different macroscopic properties. In this study the behaviour of Metallic Hollow Spheres Structures due to structure-borne sound is investigated. Longitudinal vibrations within a rod serve as an example. Experimental data are compared with analytical solutions and results computed by the finite element method. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Veyhl C.,University of Newcastle | Belova I.V.,University of Newcastle | Murch G.E.,University of Newcastle | Ochsner A.,Technical University of Malaysia | Fiedler T.,University of Newcastle
Finite Elements in Analysis and Design | Year: 2010

This paper addresses the mesh-dependence of non-linear mechanical finite element analysis. To this end, finite element meshes that are assembled by various element types and their solutions are compared. Voxel, tetrahedron, hexahedron and mixed (hex-dominant) meshes are considered. Different benchmarking parameters for the elastic and plastic solutions as well as for the computational load are determined. First, bending beams with a square, a circular and a rail cross-section are calculated accounting for non-linear material behaviour (plasticity). A strong dependence on the mesh type is observed and the best results are obtained for mixed meshes and hexahedron-only meshes. In the second part of this study, finite element models that are based on the complex geometry of metallic foam are considered. Computed tomography data is used to generate geometrically complex finite element models and a convergence analysis is performed. Again, superior performance is found for mixed meshes. Crown Copyright © 2010. Source

Abdullah A.R.,Technical University of Malaysia Malacca | Sha'Ameri A.Z.,Technical University of Malaysia
Eurasip Journal on Advances in Signal Processing | Year: 2010

Bilinear time-frequency distributions (TFDs) are powerful techniques that offer good time and frequency resolution of time-frequency representation (TFR). It is very appropriate to analyze power quality signals which consist of nonstationary and multi-frequency components. However, the TFDs suffer from interference because of cross-terms. Many TFDs have been implemented, and there is no fixed window or kernel that can remove the cross-terms for all types of signals. In this paper, the bilinear TFDs are implemented to analyze power quality signals such as smooth-windowed Wigner-Ville distribution (SWWVD), Choi-Williams distribution (CWD), B-distribution (BD), and modified B-distribution (MBD). The power quality signals focused are swell, sag, interruption, harmonic, interharmonic, and transient based on IEEE Std, 1159-1995. A set of performance measures is defined and used to compare the TFRs. It shows that SWWVD presents the best performance and is selected for power quality signal analysis. Thus, an adaptive optimal kernel SWWVD is designed to determine the separable kernel automatically from the input signal. © 2010 Abdul Rahim Abdullah and Ahmad Zuri Sha'ameri. Source

Ochsner A.,Technical University of Malaysia | Ochsner A.,University of Newcastle | Hosseini S.M.H.,Technical University of Malaysia | Merkel M.,Aalen University of Applied Sciences
Journal of Materials Science and Technology | Year: 2010

This paper investigated the uniaxial mechanical properties of a new type of hollow sphere structures. For this new type, the sphere shell was perforated by several holes in order to open the inner sphere volume and surface. The mechanical properties, i.e. elastic properties and initial yield stress of perforated hollow sphere structures (PHSS) in a primitive cubic arrangement were numerically evaluated for different hole diameters and different joining techniques of the hollow spheres. The results are compared to classical configurations without perforation. © 2010 The Chinese Society for Metals. Source

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