An annular motor core has a plurality of split core pieces, each of which includes a yoke portion and a tooth. During operation, the system receives a request to interact with the user, wherein the request is received at a user proxy server, which services requests for interactions with users. The fingertip portions are respectively provided at tip end portions of the intermediate links. The microprocessor receives the sets of digital signals in a period of sampling time and determines the content of the specific component based on the sets of digital signals. The masking material layer and the BPSG layer, which function as a multilevel hard mask, are used to physically etch the multilayer structure to form a trench therein. The product matrix is the product of a model-view matrix and a projection matrix.