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Strategies can significantly influence the performances of individual players and groups in supply networks. However, these strategies evolve over time. Thus, it is essential to probe the evolution of strategies in this context. This paper investigates the evolution of cooperation on supply networks focusing on the impacts of network topologies. Due to the difficulty in mapping the topological structures of large-scale supply networks, we introduce a topological model for supply networks. Then repeated prisoner’s dilemma game is played on the resulting networks. The simulation results show that topological structures have close relevance to the cooperation level in the networks. Compared with homogeneous structures, heterogeneous structures are helpful to promote cooperation. In addition, strategy payoff and competition pressure are also involved with the evolution of cooperation. This work may offer a useful insight into understanding complex strategy behaviours in supply networks.

The grave interferences in the calculus of bounded capacities(BoCa) can be regarded as programming errors and could be disastrous. In order to avoid the problems and to control the movement of resources, some BoCa primitives are modified. A new calculus, the safe bounded capacities (Safe BoCa) is proposed that modifies two capacities and adds three new capabilities and two new co-capabilities. The reduction semantics is modified accordingly. A type system for the safe BoCa is given to control the mobility of ambients and the number of threads, and to guarantee that the intended capacity bounds are statically preserved throughout computation.

Formal methods have proved useful in the analysis of security protocols. The paper proposes a generic model for the analysis of the security protocols (GSPM for short) that supports message passing semantics and constructs for modelling the behavior of agents. GSPM is simple, but it is expressive enough to express security protocols and properties in a precise and faithful manner. Using GSPM it is shown how security properties such as confidentiality, authentication, non-repudiation, fairness, and anonymity can be described. Finally an example of formal verification is illustrated.

This paper presents a mathematical model for computing the effects of air humidity, fuel composition, and gas dissociation on gas turbine engine performance and its actual application to a computer program for simulation of gas turbine engine performance. A new generalized modular program to allow for these effects was built, which is called ‘TURBOFLEXI’. It can simulate arbitrary gas turbine engine with a variety of configurations, at any air humidity conditions, with any fuel composition and gas dissociation or even water injection. The program was examined by test data and published data.Copyright © 1985 by ASME

This paper presents a computer model called ‘TURBOTEST’ which is applicable both to analysis of gas turbine engine rig tests and to simulation of engine steady-state performance. As with the earlier ‘TURBOFLEXI’ model a wide range of gas turbine engines can be simulated, using any kind of hydrocarbon fuel, and allowing for chemical dissociation of the gas, and for the effect of air humidity. In addition, however, for the particular requirements of rig test analysis, the following new features have been developed and incorporate:- (a) It can carry out rig test analysis for a wide range of gas turbine engines if all the necessary test data are presented. (b) If the test data is incomplete, a computer simulation of the engine can be used to complete the analysis. (c) Performance deterioration of engine components can be detected by comparing the results of a test analysis and of a parallel simulation using stored characteristics of engine components in the “as new” condition. The program has been tested on simulated test data generated by engine models such as a turbojet and a turbofan. The results show it has close and repeatable agreement with design values. Further tests of the model have been carried out by applying it to the actual engine rig test data.