Current Issue : January - March Volume : 2014 Issue Number : 1 Articles : 6 Articles
Suffiicient and realistic conditions are established in this paper for the existence and global attractivity of a positive periodic solution\r\nto the neutral multidelay logarithmic population model with impulse by using the theory of abstract continuous theorem of k-set\r\ncontractive operator and some inequality techniques. The results improve and generalize the known ones in Li 1999, Lu and Ge\r\n2004, Y. Luo and Z. G. Luo 2010, andWang et al. 2009. As an application, we also give an example to illustrate the feasibility of our\r\nmain results....
Nowadays, most of the dynamic research on planing ships has been directed towards analyzing the ships motions in either 3-\r\nDOF (degrees of freedom) mode in the longitudinal vertical plane or in 3-DOF or 4-DOF mode in the lateral vertical plane. For\r\nthis reason, the current authors have started a research program of describing the dynamic behavior of planing ships in a 6-DOF\r\nmathematical model. This program includes the developing of a 6-DOF computer simulation program in the time domain. This\r\ntype of simulation can be used for predicting the response of these planing vessels to the environmental disturbances during highspeed\r\nsailing. In this paper, the development of themathematicalmodel will be presented. Furthermore, a discussion will be offered\r\nabout the use of these static contributions in a time domain simulation for modeling the behavior of planing crafts in regular waves....
In order to satisfy the character of parallel hybrid electric vehicle (PHEV) in some special driving cycles, a collision decision problem\r\nbetween the shift decision and power split ratio is proposed. Based on a large amount of experimental data the optimal decisions are\r\ndetermined with evidential reasoning theory.The proposed decision strategy has been verified through real road test of Chongqing\r\npublic transportation line 818 and the fuel economic improvement has also been achieved....
This paper investigates the mobility of a family of fully translational parallel manipulators based on screw system analysis by\r\nidentifying the common constraint and redundant constraints, providing a case study of this approach. The paper presents the\r\nbranch motion-screws for the 3-R??C-Y parallel manipulator, the 3-RCC-Y (or 3-R??RC-Y) parallel manipulator, and a newly\r\nproposed 3-R??C-T parallel manipulator. Then the paper determines the sets of platform constraint-screws for each of these three\r\nmanipulators. The constraints exerted on the platforms of the 3-R??C architectures and the 3-RCC-Y manipulators are analyzed\r\nusing the screw system approach and have been identified as couples. A similarity has been identified with the axes of couples:\r\nthey are perpendicular to the R joint axes, but in the former the axes are coplanar with the base and in the latter the axes are\r\nperpendicular to the limb. The remaining couples act about the axis that is normal to the base. The motion-screw system and\r\nconstraint-screw system analysis leads to the insightful understanding of the mobility of the platform that is then obtained by\r\ndetermining the reciprocal screws to the platform constraint screw sets, resulting in three independent instantaneous translational\r\ndegrees-of-freedom. To validate the mobility analysis of the three parallel manipulators, the paper includes motion simulations\r\nwhich use a commercially available kinematics software....
In view of the fact that the classical fast motion estimation methods are easy to fall into local optimum and suffer the high\r\ncomputational cost, the convergence of the motion estimation method based on the swarm intelligence algorithm is very slow.\r\nA new block motion estimation method based on single-dimension perturbation glowworm swarm optimization algorithm is\r\nproposed. Single-dimension perturbation is a local search strategywhich can improve the ability of local optimization.Theproposed\r\nmethod not only has overcome the defect of falling into local optimum easily by taking use of both the global search ability of\r\nglowwormswarmoptimization algorithm and the local optimization ability of single-dimension perturbation but also has reduced\r\nthe computation complexity by using motion vector predictor and terminating strategies in view of the characteristic of video\r\nimages. The experimental results show that the performance of the proposed method is better than that of other motion estimation\r\nmethods for most video sequences, specifically for those video sequences with violentmotion, and the searching precision has been\r\nimproved obviously. Although the computational complexity of the proposed method is slightly higher than that of the classical\r\nmethods, it is still far lower than that of full search method....
Mathematical models, such as sets of equations, are used in engineering to represent and analyze the behaviour of physical systems.\r\nThe conventional notations in formulating engineering models do not clearly provide all the details required in order to fully\r\nunderstand the equations, and, thus, artifacts such as ontologies,which are the building blocks of knowledge representationmodels,\r\nare used to fulfil this gap. Since ontologies are the outcome of an intersubjective agreement among a group of individuals about\r\nthe same fragment of the objective world, their development and use are questions in debate with regard to their competencies\r\nand limitations to univocally conceptualize a domain of interest. This is related to the following question: ââ?¬Å?What is the criterion\r\nfor delimiting the specification of the main identifiable entities in order to consistently build the conceptual framework of the\r\ndomain in question?ââ?¬Â This query motivates us to view the Yoneda philosophy as a fundamental concern of understanding the\r\nconceptualization phase of each ontology engineering methodology. In this way, we exploit the link between the notion of formal\r\nconcepts of formal concept analysis and a concluding remark resulting from the Yoneda embedding lemma of category theory in\r\norder to establish a formal proces...
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