tailieunhanh - Elementary mathematical and computational tools for electrical engineers using Matlab - Chapter 10

A Taste of Probability Theory* Ngoài ra để sử dụng hàng ngày của nó trong tất cả các khía cạnh của cuộc sống công cộng, cá nhân, và giải trí của chúng tôi, xác suất đóng một vai trò quan trọng trong thực hành kỹ thuật điện trong ít nhất ba khía cạnh quan trọng. Đây là công cụ toán học để đối phó với ba lĩnh vực chính: 1. Các vấn đề liên quan với sự không chắc chắn vốn có trong các đầu vào của các hệ thống nhất định. Các thời gian đến ngẫu nhiên của các. | 10 A Taste of Probability Theory Introduction In addition to its everyday use in all aspects of our public personal and leisure lives probability plays an important role in electrical engineering practice in at least three important aspects. It is the mathematical tool to deal with three broad areas 1. The problems associated with the inherent uncertainty in the input of certain systems. The random arrival time of certain inputs to a system cannot be predetermined for example the log-on and the log-off times of terminals and workstations connected to a computer network or the data packets arrival time to a computer network node. 2. The problems associated with the distortion of a signal due to noise. The effects of noise have to be dealt with satisfactorily at each stage of a communication system from the generation to the transmission to the detection phases. The source of this noise may be due to either fluctuations inherent in the physics of the problem . quantum effects and thermal effects or due to random distortions due to externally generated uncontrollable parameters . weather geography etc. . 3. The problems associated with inherent human and computing machine limitations while solving very complex systems. Individual treatment of the dynamics of very large number of molecules in a material in which more than 1022 molecules may exist in a quart-size container is not possible at this time and we have to rely on statistical averages when describing the behavior of such systems. This is the field of statistical physics and thermodynamics. Furthermore probability theory provides the necessary mathematical tools for error analysis in all experimental sciences. It permits estimation of the 2001 by CRC Press LLC error bars and the confidence level for any experimentally obtained result through a methodical analysis and reduction of the raw data. In future courses in probability random variables stochastic processes .