A method is given for creating material with a desired refraction coefficient. The method consists of embedding into a material with known refraction coefficient many small particles of size a. The number of particles per unit volume around any point is prescribed, the distance between neighboring particles is O(a 2−κ 3 ) as a → 0, 0 < κ < 1 is a fixed parameter. The total number of the embedde...

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With the rapid development of e-commerce over Internet, web services have attracted much attention in recent years. Nowadays, enterprises are able to outsource their internal business processes as services and make them accessible via the Web. Then they can dynamically combine individual services to provide new value-added services. A main problem that remains is how to discover desired web ser...