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Cognitive radio can use the hole of licensed spectrum efficiently without interference to the primary users through sensing the wireless environment dynamically. An improved algorithm of spectrum allocation based on graph-coloring theory is proposed in this paper. It can significantly reduce the cost of allocating channels through parallel allocation thus enhance the extent of reusing channels but causing no interference between cognitive users. Simulation proves that the cost of this algorithm is only slightly greater than the parallel algorithm while its system reward is obviously higher than that of former algorithms. As a result it will further optimize the spectrum allocation and boost the spectrum utilization.

I use 2005-2017 Shenzhen and Shanghai's A-share listed company's quarterly earnings forecasts data as sample to perform multiple regression analysis. I find that when inflation rate rises, not only management's possibility of making earnings forecasts but also the precision and accuracy of management forecasts declines, ceteris paribus. Furthermore, I also find that when inflation rate rises, the state-owned nature of enterprises will aggravate the decline in the precision and accuracy of listed companies' earnings forecasts. In the unique context of semi-mandatory disclosure rules in China, if companies voluntarily disclose more performance-related information, it usually means that the managers are more capable, more confident. Therefore, this voluntary behavior can alleviate the decline in the precision and accuracy of the earnings forecast brought by inflation. Finally, I find that the precision and accuracy of the earnings forecasts will further decline for companies with higher debt ratios, indicating that liabilities may be one of the paths of inflation affecting voluntary information disclosure.

A QoS routing protocol (IQAODV) is proposed in this paper which integrated delay and bandwidth by establishing the relationship between delay and bandwidth to converse bandwidth to delay, and resolves the problem that intermediate node cannot send RREP information in QAODV routing protocol. The performance of IQAODV is much better than QAODV's and IQAODV is more suitable to transmit multi-media traffic by the simulation results.