Profiles type selection is very important for scroll compressor. Inherent engagement mechanism was discovered in the study of scrolls. And a novel method for scroll profiles based on inherent engagement mechanism is proposed. The result shows that the engagement region angle (ERA) of odd regular polygon involutes is half of the characteristic-geometry exterior angle, and that of even regular polygon involutes is equal to the exterior angle to the moment. The corresponding ERA is reducing increasingly with the edge number increasing of characteristic geometry. The performance characteristics of scroll compressor tend towards the best correspondingly. Aiming at existed problems of profile design for scrolls, it developed a novel methodology to study scroll profile. Originality research was done for the further study of scroll profile. It is the fundamentality factor representing essence character of scroll profiles function itself.
Metro networks have evolved dynamically since its position in the network infrastructure. To gain competitive advantage in this attractive market, carriers should emphasize not only just the power of their networks in terms of the speed, number of channels, distance covered, but also the network's versatility in supporting variety of access interfaces, flexibility in bandwidth provisioning, ability of differentiated service offering, and capability of network management. Based on an overview of four emerging metro network technologies, an intelligent metro network control platform is introduced. The intelligent control platform is necessary for carriers to meet the new metro requirements. Intelligent control and management functions of the platform are proposed respectively. Intelligent metro network will bridge the metro gap and open up a whole new set of services and applications.