The mathematical model of braking torque on eddy current retarder is analyzed. Aim at the shortages that comparing real output torque of eddy current retarder at high velocity the error of the mathematical model's...
详细信息
The mathematical model of braking torque on eddy current retarder is analyzed. Aim at the shortages that comparing real output torque of eddy current retarder at high velocity the error of the mathematical model's computation torque is big, a braking torque model based on neural network model is proposed. The neural network model of eddy current retarder is established in terms of the braking torque's characteristics. The existing control system of eddy current retarder is studied and a novel PWM control system based on neural network model is proposed. The capabilities of mathematical model and neural network model are compared in terms of the experiment and testify the braking torque model based on neural network model is more valid
Intrusion detection is an important technique in the defense-in-depth network security framework and a hot topic in computer network security in recent years. In this paper, a new efficient intrusion detection method ...
详细信息
ISBN:
(纸本)0780384032
Intrusion detection is an important technique in the defense-in-depth network security framework and a hot topic in computer network security in recent years. In this paper, a new efficient intrusion detection method based on hidden Markov models (HMMs) is presented. HMMs are applied to model the normal program behaviors using traces of system calls issued by processes. The output probability of a sequence of system calls is calculated by the normal model built. If the probability of a sequence in a trace is below a certain threshold, the sequence is flagged as a mismatch. If the ratio between the mismatches and all the sequences in a trace exceeds another threshold, the trace is then considered as a possible intrusion. The method is implemented and tested on the sendmail system call data from the University of New Mexico. Experimental results show that the performance of the proposed method in intrusion detection is better than other methods.
暂无评论