Papers by Keyword: Optimal Scheme

Abstract: In multiuser MIMO uplink communications, it is necessary to design linear schemes that are able to suppress co-channel interferences (CCIs). In this paper, we propose a linear block QR decomposition (BQRD) which transforms the multiuser channel to a block upper triangular structure based on Gram-Schmidt orthonormalization and can obtain more diversity gain than traditional BD. And a optimal ordering criterion is proposed at last to do full study of BQRD scheme. Simulation results show that the BQRD with the optimal ordering proposed achieves much better performance than the non-ordering one.

Abstract: Established a hierarchy structure model and made a quantitative assessment of seven air-conditioning systems which are gas boiler plus electric refrigerating system、air-cooled heat pump、variable refrigerant volume air conditioning、ground-source heat pump air conditioning、centralized heat-supply plus electric refrigerating、gas direct-fired machine、energy storage on relevant professionality and indoor environment,initial investment,operating costs,operation and management,environmental impact,energy consumption.Finally we obtained an optimal scheme,which agreed with that in practice.

Abstract: The precise face grinding and lapping technology with abrasive or abrasive tool has been widely used in the field of the precise manufacture and ultraprecise manufacture. It has become an essential technology in the manufacture of many components. The planetary lapping machine is typical equipment for face grinding or lapping process. And the relative motions between the workpieces and grinding wheel will affect the formation of wear profiles of the tools, furthermore, the work result will be affected directly by the cutting path of this relative motions. In this paper, the kinematic principle of face grinding process on lapping machines has been analyzed. By means of the concept of pitch point and pitch circles, the complicated grinding process has been converted into two kinds of rotations with the fixed center distance. Two kinds of path curves, i.e. workpiece against grinding wheel and grinding wheel against workpiece, and their relations are analyzed. The geometrical analyses and the manufacture quality of the workpiece are linked with the aid of the cutting velocity, the range of the rotational angle of the cutting traces and the rate of the change of the rotational angle with time. The optimal path curve and kinematic parameters are achieved, and these results are corresponding to the experimental results.