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191.
192.
对数字通信中MPSK系统的调制与解调问题进行了较为的分析,并以8PSK和循环码16PSK系统为例,阐述其调制器电路的逻辑设计方法。在此基础上给出了8PSK系统调制与解调的一种方案,讨论了循环码和自然二进制码16PSK系统的调制器的具体设计过程,该设计方法可应用于一般MPSK系统的逻辑设计。  相似文献   
193.
Results of a numerical investigation of heat and mass transfer at the initial stage of fire within a building in combustion of kerosene, carried out with the use of a three-dimensional mathematical field model, are presented. A comparison of the distribution of the averaged temperatures and velocities along the vertical axis of the convective column and of the mass rates of gas flows through an open opening with the experimental data has been made. Substantial three-dimensional inhomogeneities of the velocities and the temperatures in the near-ceiling layer have been revealed. It has been established that near the opening there is a critical separation zone which influences significantly the parameters of natural gas transfer.  相似文献   
194.
Experimental data on the pulsed laser radiation confinement in compensated GaAs and ZnSe with deep impurity levels are reported for the laser wavelength λ=1.55 μm and a pulse repetition frequency of up to 100 kHz. It is demonstrated that an increase in the pulse repetition rate is accompanied by a decrease in the energy confinement threshold and by an increase in the radiation attenuation coefficient. These effects are explained by the accumulation of nonequilibrium charge carriers related to a dependence of the recombination time constant on the concentration of free impurity centers.  相似文献   
195.
Spatial distributions of the average and coherent intensities of the electromagnetic field in a stochastic, strongly fluctuating discrete nonlossy medium are studied by experimental and theoretical methods. It is established that, at a certain density of the medium, the average field intensity near the source immersed into this medium can significantly exceed the value in the free space.  相似文献   
196.
The properties of the solutions of optimal parametric filtration equations and an adaptive variant of the problem with regard for time-drift of the unknown parameters of the system are studied. Along with the Kalman interpretation of the optimal adaptive nonlinear filter, the Bayes approach to applying the respective a posteriori densities is also studied.  相似文献   
197.
This study empirically examined the organisational learning effects of the nonfinancial performance information provided by management accounting information systems (MAISs) under advanced manufacturing technology (AMT). In this study, a target costing system and the frequent and quick reporting of information were considered the facilitators of learning. First, we examined the relationships between AMT level and the amount of nonfinancial performance information produced by MAISs. The empirical results showed that there are significant positive relationships between the level of AMT and nonfinancial performance information. With a systems approach, we also proved the impact of the relationships among AMT levels, nonfinancial performance information and learning facilitators on the organisational performance of a firm. The results of our research suggest that under a high level of AMT, for the provision of information to result in an increase of performance through organisational learning, a target costing system must be introduced and a large amount of information should be provided frequently and quickly. The results of this study also showed that although AMT level may be low, fairly well-arranged facilitators and a moderately large amount of information may be necessary for the improvement of performance. In conclusion, effective organisational learning depends on the provision of relevant information as well as efficient learning support mechanisms.  相似文献   
198.
Consideration was given to the decision making procedures based on the fuzzy messages of experts whose preferences on the set of collective decisions can also be fuzzy.  相似文献   
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