119556859
Eventual practical stability of impulsive differential equations with time delay in terms of two measurements
In this paper we introduce a new stability--eventual practical stability for impulsive differential equations with time delay. By using Lyapunov functions and comparison principle, we will get some criteria of eventual practical stability, eventual practical quasistability and strong eventual practical stability for impulsive differential equations with time delay in terms of two measurements.
205929604
Boundedness of the solutions of impulsive differential systems with time-varying delay
In this paper, we investigate boundedness of the solutions of impulsive functional differential equations with time-varying delay by using Lyapunov functions and Razumikhin techniques. We will see that impulses do contribute to the solutions' boundedness property.
15793976
A New Sub-path Protection Algorithm Based on Auxiliary Virtual Topology in WDM Optical Networks
This paper proposes a new survivable algorithm named sub-path protection based on auxiliary virtual topology (SPAVT) to tolerate the single-link failure in WDM optical networks. According to the protection-switching time constraint, SPAVT constructs the virtual topology. Then, it only needs to run one time of routing algorithm to find the feasible virtual route in virtual topology. Simulation results show that SPAVT has smaller blocking probability and lower time complexity than conventional algorithms.
11247110
Sustaining Incentive in Grid Resource Allocation: A Reinforcement Learning Approach
Encouraging resource sharing and cooperation among different parties is one of the central goals of grid computing. In real environments, however, selfish or malicious nodes can seriously degrade the sharing and cooperation performance of a grid. To solve this problem, we propose QIA, a novel Q-learning based resource Allocation mechanism that sustains Incentive for every participating node. Exploiting an economic model, QIA recognizes the importance of trust factor when allocating resources. Each provider considers a combined metric, which is composed of the bid price and the trust value, of a requester when allocating its resources. The incomplete information is a key issue for a provider in determining the relative weight of bid price and trust value. We propose a reinforcement Q- learning technique to resolve the issue, which is able to adapt the dynamics of grid environments. We implemented QIA in a real grid test-bed, CROWN grid. Comprehensive experiments have been conducted, which demonstrate the efficacy of QIA.
8620934
Certifying Concurrent Programs Using Transactional Memory
Transactional memory (TM) is a new promising concurrency-control mechanism that can avoid many of the pitfalls of the traditional lock-based techniques. TM systems handle data races between threads automatically so that programmers do not have to reason about the interaction of threads manually. TM provides a programming model that may make the development of multi-threaded programs easier. Much work has been done to explore the various implementation strategies of TM systems and to achieve better performance, but little has been done on how to formally reason about programs using TM and how to make sure that such reasoning is sound. In this paper, we focus on the semantics of transactional memory and present a proof-carrying code (PCC) system for reasoning about programs using TM. We formalize our reasoning with respect to the TM semantics, prove its soundness, and use examples to demonstrate its effectiveness.
40389264
Application of Efficient Numerical Methods in Solution of Ordinary Differential Equations for Modeling Electrical Activity in Cardiac Cells
There is a large number of ordinary differential equations (ODEs) characterize the electrical behavior generated by ionic movements in human myocardial cell. In this paper, several approaches were investigated in order to improve the efficiency of solving the ODE systems for ten Tusscher et al.’s ionic model of human ventricular tissue. By using non-standard finite difference (NSFD) scheme, the stiffness of the ODEs system will be successfully reduced, so a larger step-size can be used. A popular multi-step method called backward differentiation formulation (BDF) was also incorporated into the computational model for testing the largest possible time steps. The results show that NSFD can be as much as 10 times more efficient than standard forward Euler in single cell model simulation while maintaining an acceptable level of accuracy. The investigation of BDF method shows that a large step size is not recommended for the single cell simulation application. All solvers were coupled to the partial differential equations for the complete simulation of heart tissue, and such computation scheme may be a good calculation technique in heart modeling and simulation.
12359586
Verifying Anonymous Credential Systems in Applied Pi Calculus
Anonymous credentials are widely used to certify properties of a credential owner or to support the owner to demand valuable services, while hiding the user's identity at the same time. A credential system (a.k.a. pseudonym system) usually consists of multiple interactive procedures between users and organizations, including generating pseudonyms, issuing credentials and verifying credentials, which are required to meet various security properties. We propose a general symbolic model (based on the applied pi calculus) for anonymous credential systems and give formal definitions of a few important security properties, including pseudonym and credential unforgeability, credential safety, pseudonym untraceability. We specialize the general formalization and apply it to the verification of a concrete anonymous credential system proposed by Camenisch and Lysyanskaya. The analysis is done automatically with the tool ProVerif and several security properties have been verified.