Xu Manwu

A symmetric cryptography based on extended cellular automata

Based on the basic theory of cellular automata (CA), using genetic algorithm to find the rules of CA, one-dimensional extended non-uniform CA is constructed to generate high quality random bit numbers. A stringent test of randomness is applied to the bit numbers. The results show that our extended CA generator outperforms other generators such as shift register generator, congruential generator and lagged Fibonacci generator. This generator can meet the requirement of the security for cryptographic modules and provide a new method to generate pseudo-random numbers in cryptography. An example of image encryption is also provided for illustration.

Agent service matchmaking algorithm for autonomic element with semantic and QoS constraints

Agent service description and matchmaking problem for autonomic element has been taken as one of the most important issue in the field of autonomic computing based on agent and multi-agent system. Considering the semantic and QoS for capability description of agent service are two important issues during matchmaking, the factors of semantic and QoS during matchmaking are considered together, and an agent service description model named ASDM_SQ is proposed. On basis of this model, a matchmaking algorithm with semantic and QoS constraints named ASMA_SQ is presented to find the agent service satisfied both the given semantic similarity threshold and optimal QoS performance. The proposed algorithm lies over two fundamental processes: semantic similarity matchmaking and QoS matchmaking. During QoS matchmaking, evaluation mechanism of confidence of individual QoS attributes, i.e. fidelity factor is introduced to overcome drawbacks such as subjectiveness and unfairness and improve the self-configuration capability for agent element. Simulation experiments demonstrate the effective and correction of our algorithm for agent service matchmaking, and perform better QoS performance than other existing algorithm, which can further show that our algorithm has better compromise between attribute quality and users’ evaluation when selecting agent service. 2009 Elsevier B.V. All rights reserved.

A Root-fault Detection System of Grid Based on Immunology

According to the immunology principles of bionics, a grid root-fault detection system is presented. In this paper event detection sequences are viewed as analogous to peptide. With the principle of positive selection in immunology, the system builds up its event database. And the behavior whose frequency is higher will be analyzed and processed first to improve the speed and effectiveness of fault detection. The experiment system implemented by this method shows a good diagnostic ability

A framework for dynamic software architecture-based self-healing

Self-healing is an active topic in areas like large complex distributed systems and continuous running systems, such as telephone switching systems, banking systems, mobile embedded systems. The architecture-based self-healing approach uses the architectural model as a basis for system reconfiguration. In architecture-based self-healing systems, the architectures may also be changed. The architectures that change during systems execution are dynamic software architectures. In this paper, a dynamic software architecture-based approach to self-healing is proposed. In the approach, architectural reflection is used to make the system architectures observable and controllable. Moreover, architectural style is used to ensure the consistency and correctness of the changes.

Agent language NUML and its reduction implementation model based on HOπ

Higher--order p--calculus(HOp)[3.4.6]] is a computation model with sufficient computation capability. It is suitable to describe the concurrency in computation. In this paper, the agent language NUML which is designed to describe DAI (distributed artificial intelligence) systems is presented; also its semantics in HOp is given and finalliy a reduction implementation model of NUML based on HOp is submitted.Higher--order π--calculus(HOπ)[3.4.6]] is a computation model with sufficient computation capability. It is suitable to describe the concurrency in computation. In this paper, the agent language NUML which is designed to describe DAI (distributed artificial intelligence) systems is presented; also its semantics in HOπ is given and finalliy a reduction implementation model of NUML based on HOπ is submitted.

The design of data-link equipment redundant strategy

A framework model proposed in this paper is a data-link Equipment Redundant Strategy based on reliability theory. The strategy combined with the normal maintenance could greatly improve the performance of the network system. The static-checking and policy of authentication mechanism ensure the running network without any error. The redundant equipments are independent but are capable of communication with each other when they work their actions. The model is independent of specific application environment, thus providing a general-purpose framework for fault diagnosis. An example is given to express the calculating method.A framework model proposed in this paper is a data-link Equipment Redundant Strategy based on reliability theory. The strategy combined with the normal maintenance could greatly improve the performance of the network system. The static-checking and policy of authentication mechanism ensure the running network without any error. The redundant equipments are independent but are capable of communication with each other when they work their actions. The model is independent of specific application environment, thus providing a general-purpose framework for fault diagnosis. An example is given to express the calculating method.

A formal semantics for DAI language NUML

Traditional AI systems are brittle in the sense that they fail miserably when presented with problems even slightly outside of their limited range of expertise. A powerful, extensible strategy of Distributed Artificial Intelligence (DAI) for overcoming such bounds is to put the system in a society of systems. So the ability to coordinate group activities of individuals and to communicate between each other is necessary for a language describing DAI systems. Agent-oriented language NUML is such a language. It is a specific kind of object-oriented language. To give formal semantics to NUML, there is the problem to formalise object-oriented programming paradigm which is still open. The theory of higher-order π-calculus is a concurrent computation model with sufficient capability, which provides us a mathematical tool to do the formalization. This paper tries to use higher-order π-calculus to formalise NUML.