ALBERT

Beschreibung: In this paper, a new beam shape function configuration method for determining transient responses of a finite Euler-Bernoulli beam with two intermediate supports excited by moving pressure wave loads is developed. To clarify this method, this beam structure is excited by the moving sinusoidal loads as an example. Transient responses of this beam structure are investigated and verified by the traditional finite element method. This method can be used to solve transient response problems of moving pressure loads exciting the beam structure with intermediate support. Actually it can be extended to solve other complicated beam structure problems. Content Type Journal Article Pages - DOI 10.3233/SAV-2012-0682 Authors Biaobiao Zhang, Department of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL, USA Steve Shepard, Department of Mechanical Engineering, The University of Alabama, Tuscaloosa, AL, USA Journal Shock and Vibration Online ISSN 1875-9203 Print ISSN 1070-9622

Beschreibung: An analytical approach is presented to obtain the sloshing natural frequencies and modes of ideal liquid in a rigid cylindrical container with a rigid annular baffle. The free surface waves of the liquid are considered in the analysis. The artificial interfaces are introduced to divide the complicated liquid domain into several simple sub-domains. The exact analytical solutions of velocity potential of liquid corresponding to every sub-domain are obtained by using the method of separation of variables and the superposition principle. The Eigen-frequency equation is precisely derived by using the Fourier-Bessel expansion on the free surface and the artificial interfaces of the liquid. The convergence study shows high accuracy and fast convergence of the present approach. The comparative studies with those available from literature are made, excellent agreements have been achieved. Numerical results showing the variations of natural frequencies and modes versus position and inner diameter of the annular baffle are provided. Content Type Journal Article Pages - DOI 10.3233/SAV-2012-0681 Authors J.D. Wang, College of Civil Engineering, Nanjing University of Technology, Nanjing, China D. Zhou, College of Civil Engineering, Nanjing University of Technology, Nanjing, China W.Q. Liu, College of Civil Engineering, Nanjing University of Technology, Nanjing, China Journal Shock and Vibration Online ISSN 1875-9203 Print ISSN 1070-9622

Beschreibung: Vibration signals acquired from bearing have been found to demonstrate complicated nonlinear characteristics in literature. Fractal geometry theory has provided effective tools such as fractal dimension for characterizing the vibration signals in bearing faults detection. However, most of the natural signals are not critical self-similar fractals; the assumption of a constant fractal dimension at all scales may not be true. Motivated by this fact, this work explores the application of the multi-scale fractal dimensions based on morphological cover (MC) technique for bearing fault diagnosis. Vibration signals from bearing with seven different states under four operations conditions are collected to validate the presented MFD based on MC technique. Experimental results reveal that the vibration signals acquired from bearing are not critical self-similar fractals. The MFD can provide more discriminative information about the signals than the single global fractal dimension. Furthermore, three classifiers are employed to evaluate and compare the classification performance of the MFD with other feature extraction methods. Experimental results demonstrate the MFD to be a desirable approach to improve the performance of bearing fault diagnosis. Content Type Journal Article Pages - DOI 10.3233/SAV-2012-0679 Authors Bing Li, Forth department, Mechanical Engineering College, Shi Jia zhuang, HeBei, China Pei-Lin Zhang, First department, Mechanical Engineering College, Shi Jia zhuang, HeBei, China Shuang-Shan Mi, Forth department, Mechanical Engineering College, Shi Jia zhuang, HeBei, China Ying-Tang Zhang, First department, Mechanical Engineering College, Shi Jia zhuang, HeBei, China Dong-Sheng Liu, Forth department, Mechanical Engineering College, Shi Jia zhuang, HeBei, China Journal Shock and Vibration Online ISSN 1875-9203 Print ISSN 1070-9622

Beschreibung: A framework of imitating real human gait in 3D from monocular video of an uncalibrated camera directly and automatically is proposed. It firstly combines polygon-approximation with deformable template-matching, using knowledge of human anatomy to achieve the characteristics including static and dynamic parameters of real human gait. Then, these characteristics are processed in regularization and normalization. Finally, they are imposed on a 3D human motion model with prior constrains and universal gait knowledge to realize imitating human gait. In recognition based on this human gait imitation, firstly, the dimensionality of time-sequences corresponding to motion curves is reduced by NPE. Then, we use the essential features acquired from human gait imitation as input and integrate HCRF with SVM as a whole classifier, realizing identification recognition on human gait. In associated experiment, this imitation framework is robust for the object’s clothes and backpacks to a certain extent. It does not need any manual assist and any camera model information. And it is fitting for straight indoors and the viewing angle for target is between 60° and 120°. In recognition testing, this kind of integrated classifier HCRF/SVM has comparatively higher recognition rate than the sole HCRF, SVM and typical baseline method.

Beschreibung: Tabu search has become acceptable worldwide as one of the most efficient intelligent searches applied to various real-world problems. There have been different modifications made to the generic tabu search in recent years to achieve better performances. Among those reviewed in the introduction of this paper, the adaptive tabu search (ATS) has incorporated the backtracking and the adaptive search radius mechanisms that help accelerate the search and release it from a local solution lock. The paper explains an enhancement made to the ATS to accomplish multipath ATS (MATS) algorithms. Performances of the ATS and the MATS are evaluated using surface optimization problems, and results are presented in the paper. Finally, the MATS is applied to solve a real-world vehicle control problem.