This paper focuses on solving deadlock problems of flexible manufacturing systems (FMS) based on Petri nets theory. Precisely, one novel control transition technology is developed to solve FMS deadlock problem. This new proposed technology can not only identify the maximal saturated tokens of idle places in Petri net model (PNM) but also further reserve all original reachable markings whatever they are legal or illegal ones. In other words, once the saturated number of tokens in idle places is identified, the maximal markings of system reachability graph can then be checked. Two classical S3PR (the Systems of Simple Sequential Processes with Resources) examples are used to illustrate the proposed technology. Experimental results indicate that the proposed algorithm of control transition technology seems to be the best one among all existing algorithms.

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This research proposes a switchable non-physical LTE/WWAN antenna. It adopts the metal zone around the hinge slot, created by the existing display ground plane, keyboard ground plane, and metal hinges, to create the radiator. It then feeds a signal at the proper position in the hinge slot to effectively excite the resonance modes of the loop path around the hinge slot. Moreover, it adopts switchable feeding points to cover the LTE700/2300/2500 triple-bands required by LTE and the GSM850/900/1800/1900/UMTS penta-bands required by WWAN, respectively, and fulfils the operating requirements of fourth generation communication. In addition, since no additional deployment space and structure design for antenna is required, the design can resolve the space requirement for communication device, and provide new antenna design technology.