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To solve the privilege escalation attacks on Android App, this paper proposed a formal privilege escalation attacks detection model based on Pi calculus. It used the extended Pi calculus to model the Android App and its runtime environment, and obtained a formal behavior model. By formalizing the privilege security policy as process expressions containing the IFTHEN rule and using the properties of Pi calculus to perform process calculus and migration, it constructed the detection model, and gave out the privilege escalation attacks detection method . The analysis and experiment results show that this method has linear time and space complexity, moreover, the existing privilege security policy can be easily applied on this model to ensure the accuracy of the model. Compared with other methods, the detection accuracy is improved without sacrificing the detection efficiency. [ABSTRACT FROM AUTHOR]

Ambient calculus, which introduces the central notion of ambients to describe the computation area with boundaries, and provides the capabilities of mobility, authentication and authorization to capture the fundamental characteristics of mobile computation systems, becomes an important research area on formal-modeling theory and applications of mobile computation systems. The paper reviewed the main theoretical and applied research works and its development of ambient-based calculus, and analyzed the extended semantics and the algebra behavior analyzing methods, the spatial logics and the model checking algorithms, and the applications of formal-modeling in computation systems; and discussed the future research directions on these areas. [ABSTRACT FROM AUTHOR]

In this paper, the implicit Runge-Kutta Scheme is derived to solve the NS equations, and its characters of stability, precision and efficiency are studied respectively. Some benchmark cases are calculated to validate the capabilities of the numerical program. The results show that the implicit R-K method given in this paper has high stability, high precision and high efficiency, which make it suitable to compute the unsteady reactive nonequilibrium flow. [ABSTRACT FROM AUTHOR]

When the multiview target point clouds were registrated by common algorithm, the relevant control survey field work is usually completed by using traditional measuring equipment. Aiming at reducing contral survey field work, a new multiview target point cloud registration algorithm is proposed in this paper. In the new algorithm, the point cloud data collection and control survey field work are completed simultaneously using terrestrial laser scanner and tape equipment. The data processing work of registrating a multiview target point cloud is accomplished by introducing classical tri-lateration net adjustment theory and constructing a new error equation. Experimental results not only show the validity of the proposed alogrithm, but also prove the feasibility of using terrestrial laser scanner to complete control survey work. [ABSTRACT FROM AUTHOR]

Based on the multi-dimensional unified geometric algebra, this paper discussed the multi-vector expression and computation of multi-dimensional vector filed. The vector differentiations are computed by template convolution. With the help of the unified expression of inner and outer product of geometric product, the unified calculation method of divergence and curl and the implementation algorithm are proposed. This method can not only reproduce the geometric association between vector field divergence and rotation parameters as well as their differential geometry characteristics, but also achieve a unified and multi-dimensional coordinate-free calculation. Simulation experimental results based on the wind fields of North American suggest that our method has much better performance of contrast and smoothness against the gradient-based algorithm. It also has strong ability to deal with vector fields of high noise and provide new insights and method foundations for vector field data analysis. [ABSTRACT FROM AUTHOR]

In this paper, the rule that multiple synchronous vacations of c repairmen is firstly introduced into the k/n(G) repairable system. Suppose that the working lifetime of each component, the repair time of each failed component and the vacation time of each repairman, has an exponential distribution with the rate λ(> 0), μ(> 0) and θ(> 0), respectively. By using quasi birth-death process and matrix-geometric solution method, we discuss the steady probability that the system is in every state, and some performance characteristics, including some reliability indices queueing indices such as the steady availability, the steady failure frequency of the system and the waiting repair time of the failed component. Furthermore, the following four special cases: 1) c = 1, θ → +∞∞; 2) c = 1, k = 1, θ → +∞; 3) c = 1, k = n, θ → +∞∞; 4) c = 1, k = n - 1, θ → +∞∞, are discussed. Finally, we give the numerical example under the case c = 2, n = 6, k = 3, λ = 1/10, θ + 1/5, θ = 1/2. [ABSTRACT FROM AUTHOR]

Accounting for static generalized phased-mission systems, imperfect coverage and dependencies across phases increase complexity and difficulty of system reliability analysis obviously. Based on SEA, we present a two-level separable combinatorial method which divides mission and phase imperfect coverage. And then we add some new rules of phase algebra and a new phase dependence operation to ordinary rules and operations, which deal with the dependencies across the phases. The effective PMS-BDD approach is also synthesized in our approach to decrease the model size and computational complexity. In this paper, the approach is compared with several existing approaches by a case study, such as a family of decision diagrams called TDD and MBDD, in order to illustrate its precise, efficient and modular advantages. [ABSTRACT FROM AUTHOR]

The traditional clustering methods based on the two-dimension information are not suitable for dealing with the panel data processing, in the consideration of the multiple information characteristics of panel data and according to the "absolute index", "incremental index" and "volatility index" of the panel data, this paper reconstructed the similarity measure distance function and Ward clustering algorithm, proposed an adaptive weighting clustering method for panel data. The provided algorithm not only can degenerate into the traditional "absolute distance" clustering algorithm, but also can conduct clustering prediction for the future category of panel data. Finally, examples show that this method is both effectiveness and flexibility. [ABSTRACT FROM AUTHOR]

Multi-agent coalition formation is one of the key problems in multi-agent systems. The main research is how to dynamically generate task-oriented coalition and the optimal structure in multi-agent systems. For the establishment of a mechanism to organize agent stability completes the task that can not be completed by a single agent and reach the global optimum. This paper presents a multi-objective comprehensive evaluation model, and a multi-objective quantum evolutionary algorithm is proposed to solve multi-agent coalition formation problem. The algorithm uses coding mapping, the combination of resources and task allocation are combined to a process, which reducing the complexity of the problem. Experimental results show that the proposed algorithm can solve the multi-task agent coalition formation problem effectively and efficiently. [ABSTRACT FROM AUTHOR]