X-architecture Steiner minimal tree algorithm based on multi-strategy optimization discrete differential evolution

Global routing is an important link in very large scale integration (VLSI) design. As the best model of global routing, X-architecture Steiner minimal tree (XSMT) has a good performance in wire length optimization. XSMT belongs to non-Manhattan structural model, and its construction process cannot be completed in polynomial time, so the generation of XSMT is an NP hard problem. In this paper, an X-architecture Steiner minimal tree algorithm based on multi-strategy optimization discrete differential evolution (XSMT-MoDDE) is proposed. Firstly, an effective encoding strategy, a fitness function of XSMT, and an initialization strategy of population are proposed to record the structure of XSMT, evaluate the cost of XSMT and obtain better initial particles, respectively. Secondly, elite selection and cloning strategy, multiple mutation strategies, and adaptive learning factor strategy are presented to improve the search process of discrete differential evolution algorithm. Thirdly, an effective refining strategy is proposed to further improve the quality of the final Steiner tree. Finally, the results of the comparative experiments prove that XSMT-MoDDE can get the shortest wire length so far, and achieve a better optimization degree in the larger-scale problem.

Mobi-X Architecture Modelling for Mobile Agent using Association Pattern Mining

In a mobile agent system, if agents’ functionality can be assessed and evaluated between peers of environmental modelling, it can reduce the exploration burden of unvisited states and unseen situations, thus an effectual learning process has to be accelerated. So as to construct an accurate and effectual model in certain time period is a significant problem, specifically in complex environment. To overcome this crisis, the investigation anticipates a model based data mining approach based on tree structure to achieve co-ordination amongst the mobile agent, effectual modelling and less memory utilization. The anticipated model suggests Mobi-X architecture to mobile agent system with a tree structure for effectual modelling. The construction of tree for real time mobile agent system is utilized to generate virtual experiences like elapse time during mining of tree structure. In addition, this model is appropriate for knowledge mining. This work is inspired by knowledge mining concept in mobile agent systems where an agent can built a global model from scattered local model held by individual agents. Subsequently, it increases modelling accuracy to offer valid simulation outcome for indirect learning at initial stage of mining. In order to simplify mining procedure, this anticipated model relies on re-sampling approach with associative rule mining to grafting branches of constructed tree. The tree structure provides the functions of mobile agents with useful experience from peer to peer connectivity, indeed of combining all the available agents. The simulation outcomes shows that proposed re-sampling can attain efficiency and accelerate the functionality of mobile agents based cooperation applications.

The SwissFEL soft X-ray free-electron laser beamline: Athos

The SwissFEL soft X-ray free-electron laser (FEL) beamline Athos will be ready for user operation in 2021. Its design includes a novel layout of alternating magnetic chicanes and short undulator segments. Together with the APPLE X architecture of undulators, the Athos branch can be operated in different modes producing FEL beams with unique characteristics ranging from attosecond pulse length to high-power modes. Further space has been reserved for upgrades including modulators and an external seeding laser for better timing control. All of these schemes rely on state-of-the-art technologies described in this overview. The optical transport line distributing the FEL beam to the experimental stations was designed with the whole range of beam parameters in mind. Currently two experimental stations, one for condensed matter and quantum materials research and a second one for atomic, molecular and optical physics, chemical sciences and ultrafast single-particle imaging, are being laid out such that they can profit from the unique soft X-ray pulses produced in the Athos branch in an optimal way.