| The Internet is full of complexity.So if trying to improve the performance of Internet and redesign it by researching its structure,we have to do researches on the macroscopic topology.And topology visualization tool brings us an intuitively visual perceptual method to understand the structure of Internet topology better.According to the faults of current topology visualization tools,we design and implement a new macroscopic topology visualization tool for the complexity of Internet.It based on DirectX API and we named it as DX-Net-Viewer.DX-Net-Viewer includes an improved GEM algorithm to settle automatic layout of nodes from the Internet.The application formed an interface to make extend automatic layout algorithm possible.This is the key to topology visualization tool.Because the GEM algorithm couldn't show a smooth process of the automatic layout,we changed the impulse into velocity and attenuate the velocity by time,by which topology visualization tool shows the layout process very smoothly and lively to observe.At the other hand,the new GEM algorithm keeps the approximate result and almost the same efficiency.Since the topology visualization tool has to process the data from Internet,which has a great amount number and press the efficiency of number processing and rendering very low,we bring in the red-black tree being the basic structure of our data to deal with the sorting,inquiry and so on.It works very well.According to the experiment,the structure of red-black tree restricts time complexity of the system in a very reasonable level.This paper shows three key researches of topology visualization tool.In the final test of our program DX-Net-Viewer,the tests proved that it achieved objectives of our designs and it has a reasonable and acceptable efficiency comparing to the current topology visualization tools.And computation of characteristic values is quick and accurate.The whole process of automatic layout is lively to observe and easy to use. |
PDF Full Text Request