In this paper we report some methods which upgrade the measurement uncertainty evaluation in analysis of the prediction of the output voltage of DC Reference Standards (Fluke 732A at 1 V, 1.018 V and 10 V levels). The monitoring of long-term stability of Zener-based voltage reference standards is one of the main tasks of Primary Electromagnetic Laboratory (PEL), which is a part of the Faculty of Electrical Engineering and Computing of the University of Zagreb, and a holder of national standards of voltage in Croatia. The long-term stability of its DC Reference Standard has been analysed...
MRI of the knee is the most frequently requested MR joint study in musculoskeletal radiology. MRI gives a comprehensive examination of the knee, providing surgeons with information they cannot obtain clinically or invasively. In this paper there is estimated the sensitivity of the articulation cartilage defects imaging using MR. There were examined two animal and two human specimen knees using CT, MRI and coordinate control machine (CCM). The cartilage was artificial destroyed and the defects were measured using MRI and CCM. CT was done to verify bone damage. The outcomes obtained in MRI and...
This paper presents the problem of the assessment of the shape of osseous tissue and the size of the occurring defects using the diagnosis of computer tomography. The results of assessment of shape of chosen osseous element were presented. In second part the exampled artifacts were presented and the own artifacts elaborated in Cracow University of Technology to assess the accuracy of CT were proposed.
A concept of the model intended for measuring emotions is grounded. The efficiency of evolutionary analysis when forming the model of measuring the emotions which are contained in acoustic and visual impacts is demonstrated. The possibility to develop a corresponding measurement instrument is shown.
This contribution describes the procedure of evaluating the calibration of thermocouple by means of its comparison with the thermocouple standard. In the process of thermocouple calibration by means of comparison, the resulting uncertainty specified by applying the generalized procedure for evaluating the calibration of measuring devices with continuous scale. The advantage of this method of evaluation is the determination of uncertainties in the whole range of the calibration. The conclusion of this paper states the illustrated differencies between cases when covariances are into account or...
The paper deals with applications of cryptographic methods in design of secured versions of Distributed Measurement Systems (DMS). In the paper wide range of cryptographic algorithms is assessed and some of them are chosen and proposed as well suited to DMS specific requirements. Some specialized low power, high speed, hardware solutions for cryptographic algorithms are also suggested in the paper. Strong asymmetry of computing power and memory capacity is taken into account in both software and hardware solutions.
In order to provide a low cost system of thermal comfort, a common model of home fan, 40 cm diameter size, had its manual four-button control system replaced by an automatic speed control. The new control system has a temperature sensor feeding a microcontroller that, by using an optic coupling, DIAC or TRIAC-based circuit, varies the RMS value of the fan motor input voltage and its speed, according to the room temperature. Over a wide range of velocity, the fan net power and the motor fan input power were measured working under both control system. The temperature of the motor stator and...
In the paper a concept of the measuring instrument with distributed data processing, cooperating with PC is presented. A functional configuration of the instrument performing additional functions connected with measurement result accuracy assessment as well as respective algorithms are shown. The principles of cooperation with PC computer are discussed. The laboratory implementation of the designed instrument and scope of its use for teaching process is proposed.
This paper will discuss a newly developed implementation of low frequency accelerometer calibrations below 10 Hz. The goal is an improved low frequency accelerometer calibration methodology capable of performing superior quality measurements with significantly lower uncertainties while maintaining good throughput and the simplicity of traditional back-to-back calibration techniques. By using an optical encoder as the measurement reference instead of a traditional back-to-back reference accelerometer, limitations due to shaker stroke length are nearly eliminated, with the practical limitation...
This paper is focused on the problem of transient and notching analysis occurring in electric power system. The aim of the research was to improve DWT algorithm especially for transient detection, in order to increase performance of a multi-parameter DSP system. The method described in the paper proposes rejecting insignificant wavelet decomposition stages and takes only these stages for reconstruction transient or notching, in which predominant energies were detected. The criterion of rejecting stages is that the frequency band of disturbances reconstructed in this way should be sufficient...