This paper proposes a procedure based on statistical tools for diagnosis of PhotoVoltaic (PV) plants. As the data are acquired, statistical analyses are realized. At every new loop other data are added to the previous ones implementing a cumulative statistical analysis. In this manner it is possible to follow the trend of some specific parameters and to understand the real operation of the PV plant, as the environmental conditions change during the year. The proposed approach, based on ANOVA and Kruskal-Wallis tests, is effective in locating abnormal operating conditions. The proposed...
Fleetwide Monitoring (FWM) is the implementation of applications for monitoring, maintaining and optimizing assets from a centralized location. Fundamentally, FWM involves monitoring assets within a fleet of assets to detect operational and equipment problems earlier enough to mitigate damage, manage risk, identify performance problems, and manage business and market conditions or risks. A key part of FWM involves the use of advanced online monitoring technologies. The goal of FWM is intelligent top-down approach to plant maintenance and scheduling. The goal is accomplished by the move...
Presented standard is intended for use in time and frequency calibration laboratories as a source of UTC-synchronized time scale with high longterm stability or for clock synchronization in distributed systems and sensor networks. Similar device was utilized for measurement published in the report Evaluation of timing GPS receivers for industrial applications for the 12th IMEKO TC10 Workshop.
Node synchronization can be implemented in an Ethernet network using time protocols; e.g. IEEE 1588. Active network components like switches and routers influence the accuracy of synchronization because they affect the packet delay variation in the network. Therefore, the delay is not constant and, as well, the delay in one direction is not equal to the delay in the opposite direction. An additional device information is available in a 12th IMEKO TC10 Workshop article.
An instrument prototype, based on a measurement method relating bioimpedance and amount of drug present in a tissue under test, was realized. The instrument assesses the amount of drug conveyed through the skin by measuring impedance spectrum before and after administration. In compliance with safety regulations, the stimulus signal does not exceed the peak value of 200 µA well below the threshold of 424 µA provided by the IEC-60601 standard. In this paper, after illustrating the conceptual and physical design of hardware, firmware, and software interface, a preliminary metrological...
Recently, a stagnant or decreasing influence of the vein pattern as a biometric parameter has been observed, even though – by assessing the features of the model: universality, permanence, collectability or performance – the technology is superior to other traditional biometric parameters. The problems are mainly related to the lack of access to clear and robust images of the vein pattern for the development of processing algorithms. This paper aims to contribute to the implementation of biometric applications using optical vein scanning by optimizing a crucial part of the biometric...
In the context of condition based maintenance, carrying out diagnosis and prognosis processes is a key. For that purpose the evaluation of the condition of a machine is necessary, for which the development of physical models is useful as the response of the modelled system can be obtained in different operating conditions. In this paper, an electromechanical model for a rotary machine is presented, making special emphasis on the modelling of rolling element bearings. Thus, the response to different damaged conditions is evaluated. The proposed model is validated by comparing the simulation...
The paper gives a description of a diagnostic and monitoring system for the first Czech hydrogen-powered bus. The system captures operating characteristics which affect ride quality and mechanical damage of the vehicle. Probabilistic evaluation of data is explained and some interesting results are introduced.
Light scattering analysis is already used for roughness measurements, but it is also possible to determine defects on surfaces with this method. Therefore, the scattering distribution is recorded and analyzed using image processing. The defects lead to specific characteristics in the images, which can be assigned to them. In this process the segmentation has an important role because only the best possible separation of the error characteristic leads to good results in the further steps of the image processing chain and in the classification process. For this reason, various segmentation...