Papers by Keyword: Stochastic

Abstract: Maintenance management is an orderly procedure to address the planning, organization, monitoring and evaluation of maintenance activities and associated costs. The maintenance management allows to have an efficient tool either to the management of the preventive or curative activity, an optimization of the production tool, and finally a follow-up of the costs and the performances. A good maintenance management system can help prevent problems and damages to the operating and storage environment, extend the life of assets, and reduce operating costs.In this paper, we will first present our model on the joint management of spare parts and maintenance. We will do a simulation study of our model, presented in the first section of this paper. The results of this study are presented in the second section through the presentation of the influence of certain parameters of the model on the operation of the system under consideration. This study carried out on the graphical interface of Matlab, which is one of the performance evaluation techniques. It allows to visualize the variations and anomalies which can be reached in the system considered as an overcoming of the repair of the machines by the unforeseen breakdowns.

Abstract: Stochastic lattice structures are modeled using a generative algorithm. In particular, the voronoi tessellation technique is applied for modeling cellular solids with irregular cell geometry and variable strut sections. The ligaments are formed considering the volume and shape characteristics of the voronoi cells. This way, the strut cross section variability is linked to the adjacent cell topology. The developed geometry is used for 3D printing the structures through a high accuracy SLA 3D printer. The mechanical properties of the photosensitive resin were determined by conducting tension experiments on appropriate 3D printed specimens. The printed stochastic structures were subjected to compressive loads in order to investigate their mechanical response. A finite element model of the compressive tests using the generated geometry, is also developed. The calculated results provide a good correlation with the experimental ones and also provide precious insight for the characterization of the mechanical behavior of the tested structures.

Abstract: In this paper the Galerkin method are used to obtain approximate solution to the stochastic beam bending problem. The present method is used to analyze the static deflection of beams. The uncertainty is represented as a parameterized stochastic process. Galerkin’s method selects the weight function functions in a special way: they are chosen from the basis functions, i.e. w(x)Î{ji(x)}, ni=1. It is required that the following n equations hold true. From the approximate solution, first and second order derivatives of the response are used. This paper solves the problem of strength and safety evaluation of a linear extended structure lying on a statically inhomogeneous foundation and presents an engineering analysis method.This paper solves the problem of strength and safety evaluation of a linear extended structure lying on a statically inhomogeneous foundation and presents an engineering analysis method.

Abstract: In this paper, the problem of adaptive synchronization in pth moment is considered for stochastic complex networks with time varying delayed and no-delayed couping. By using the Lyapunov Krasovskii functional, stochastic analysis theory, sufficient condition to ensure adaptive synchronization in pth moment for stochastic time varying delayed complex networks is derived. To illustrate the effectiveness of the synchronization condition derived in this paper, a numerical example is provided finally.

Abstract: In this paper, the optimal assembly sequence is considered as precedence graph which reduces the complexity of the problem, and an exact algorithm named task-oriented enumeration is proposed to solve the single-model stochastic assembly line balancing problems of type-1. The results show the proposed algorithm can solve the single-model stochastic assembly line balancing problems of type-1.

Abstract: Retracted paper: The improvement of erasure coding has deployed scatter/gather I/O, and current trends suggest that the development of systems will soon emerge. After years of compelling research into lambda calculus, we disconfirm the visualization of superpages, which embodies the confusing principles of e-voting technology. We concentrate our efforts on confirming that Lamport clocks can be made virtual, ambimorphic, and stochastic.

Abstract: Dynamic analysis is performed for a crack in a functionally graded materials layer for plane problem using shear stress. The material properties of the functionally graded materials layer vary randomly in the thickness direction, and the cracks are parallel to the materials faces. A pair of dynamic loadings applied on the elastic planes faces are treated as stationary stochastic processes of time. By dividing the functionally graded materials layer into several sub-layers, this problem is reduced to the analysis of laminated composites containing a crack, the material properties of each layer being random variables. A fundamental problem is constructed for the solution. Based on the use of Laplace and Fourier transforms, the boundary conditions are reduced to a set of singular integral equations, which can be solved by the Chebyshev polynomial expansions. The stress intensity factor history with its statistics is analytically derived. Numerical calculations are provided to show the effects of related parameters.

Abstract: In this paper, we present a new method to build public-key Cryptosystem. The method is based on the state explosion problem occurred in the computing of average number of tokens in the places of Stochastic Petri Net (SPN). The reachable markings in the coverability tree of SPN are used as the encryption keys. Accordingly, multiple encryption keys can be generated, thus we can perform multiple encryption to get as strong security as we expect. The decryption is realized through solving a group of ordinary differential equations from Continuous Petri Net (CPN), which has the same underlying Petri net as that of SPN. The decipherment difficulty for attackers is in exponential order. The contribution of this paper is that we can use continuous mathematics to design cryptosystems instead of discrete mathematics.

Abstract: The institutional investor selling a large block of shares in the market usually faces with liquidity risk declining the stock’s prices. In the paper, supposing that temporary impact is stochastic and nonlinear function of trading velocity, we establishes the discrete mathematical model and uses PSO to obtain the optimal liquidation strategies of risk aversion, which is a strict concave function. When analyzing the sensitivity of the parameters, we find that the curve becomes higher and steeper with the increase of the parameters or the decrease of , .As the parameter is tremendous, the curve is close to a horizon line.

Abstract: This paper studies a kind of SIRS model for epidemics. By making a C2-kind function, we use It Ô formula on the model. With the help of proof by contradiction, we prove the existence and uniqueness of the solution to the model and we also prove its boundness based on this. Furthermore, we obtain the condition of the parameters in the model to make the epidemics described by SIRS model die out. In this way, suggestions can be given to prevent this kind of epidemics from spreading.