Establishment of Quick Testing Efficiency Evaluation Model and Analysis of Related Factors

Objective: “Rapid screening, targeted sampling, objective test” is an efficient test model. The factors affecting the efficiency include false screening rate, missing rate and rapid screening time. However, only missing rate and accuracy have been used as technical requirements to evaluate rapid screening method. In this study, efficiency was regarded as evaluation index of quick testing method. Method: The evaluation model of quick testing efficiency was established by comparing time of routine testing and quick testing. By simulation calculation, the effect factors such as rapid screening time, false screening rate, missing rate and defective rate were analyzed. Results: The calculation formula of efficiency was derived. Simulation results showed that the lower defective rate, the higher efficiency;the smaller missing rate, false screening rate, or screening time, the higher efficiency and the degree of improving efficiency is related to defective rate;sometimes, the screening time is the most important factor affecting the efficiency. In certain cases, if the false screening rate or missing rate is 50%, the efficiency can be increased by more than 10 times. Conclusions: Taken together, this study highlighted a role of efficiency which functioned as an index to evaluate rapid screening. Quick testing efficiency evaluation model can be used for the calculation efficiency, and can be used to analysis the relationship between efficiency and the influence factors, and can provide the theoretical foundation for rapid screening method development and evaluation.

Sensor/Actuator Faults Detection for Networked Control Systems via Predictive Control

Quantized fault detection for sensor/actuator faults of networked control systems （NCSs） with time delays both in the sensor-to-controller channel and controller-to-actuator channel is concerned in this paper. A fault model is set up based on the possible cases of sensor/atuator faults. Then, the model predictive control is used to compensate the time delay. When the sensors and actuators are healthy, an H stability criterion of the state predictive observer is obtained in terms of linear matrix inequality. A new threshold computational method that conforms to the actual situation is proposed. Then, the thresholds of the false alarm rate （FAR） and miss detection rate （MDR） are presented by using our proposed method, which are also compared with the ones given in the existin~ literatures. Finally, some numerical simulations are shown to demonstrate the effectiveness of the proposed method.