This paper describes a neural network system for power electric load forecasting of telecommunication station. Getting an accuracy useful for contractual purpose a separately daily forecast of both main load and its oscillation is proposed. For the mean daily forecast we used a three layers multi-layer perceptron (MLP), while to the oscillation forecasting we realized a system composed by a MLP and a self organizing map (SOM): the typology information obtained by the SOM unsupervised algorithm has been utilized as binary code in MLP input. The proposed system with hourly power load data of a...
The paper describes an unusual approach to diagnose standard ignition subsystem of fuel engines. All the information about real state conditions of the ignition coils and sparks is taken from simple measurement of power consumption transient of the electric control systems of engine. The transient is processed by continuous wavelet transformation (CWT). Result of the CWT is used for a classifier. Classifier is supposed to work in learning and diagnostic modes. The main output of the classifier is two disjoint states meaning correct and incorrect functional work of the engine ignition system....
A Bayesian analysis of a calibration model was presented in Metrologia , 43 (2006) S167-S177, wherein two approaches were considered to obtain the probability density function associated with the measurand. In one of them, Bayes' theorem was applied directly to an input quantity for which measurement data were available. In the other approach, that same input quantity was expressed in terms of the measurand and the other input quantities. Since the forms of the likelihood function used in each approach were not the same, different prior functions were needed. In this paper we show that both...
This paper gives details of a round robin torque comparison involving the National Physical Laboratory (NPL) and nine other UK laboratories. The comparison covered two ranges: 20 N·m to 100 N·m and 200 N·m to 1 kN·m. The work was an effective way of disseminating the unit of torque to industry via the UK's new national torque standard, giving assurance to laboratories and customers and identifying areas for possible improvement.
A newly developed hardness test based on equivalent indentation depth is currently expected to be the only hardness test method that enables seamless evaluations of hardness across different hardness scales in all load ranges from nanoscopic to macroscopic in an industrial friendly manner because the new method is free from the shortcomings of the instrumented indentation method, which requires calibration of tester frame compliance and detection of true specimen surface. However, as it is still in the early days of application, extensive data have yet to be accumulated concerning the...
The authors numerically discuss the accuracy of the hardness values of standard hardness blocks by evaluating the uniformity of hardness blocks and the resolution of hardness values according to test method. As a result of reviewing the results of this evaluation and the reasonability of the currently proposed method for evaluating the uncertainty of hardness values, it is revealed that the variance of hardness values of popular standard blocks for hardness - Rockwell and Vickers - is extremely small (σ ≤ 0.05 HRC, including the variance attributable to the tester). It is also found that the...
An experiment for the direct measurement of the atomic mass constant was performed by accumulating ions from an ion beam up to a weighable mass. The aim of this experiment was to develop an alternative approach for the redefinition of the SI unit kilogram. In a recent experiment a mass of about 300 mg bismuth was accumulated and the atomic mass unit could be determined with a relative uncertainty better than 1.0 × 10 -4 .
The weight vector theory for Coriolis flow meters has been the subject of research presented by Hemp and co-workers in various articles. The underlying theory may not be easily understood. This paper explains the application of the weight vector theory for Coriolis flowmeters. The theory is applied to simple theoretical meter configurations consisting of a single straight pipe. The application of the weight vector approach is of relevance when investigating velocity profile effects, e.g., in Coriolis flow meters. Promising results have been found in recent literature showing the...
Test of insulation resistance is pre-requisite for leakage effect evaluation in many electrical measurements. Especially high resistance measurement at low working voltage is often required for evaluation of high precision measurement system. The high resistance measurement at low voltage level with portable hand-set is a challenging task. Here we suggest a simple and convenient method to measure the insulation resistance of up to 10 TΩ order using the principle that effective resistance changes when insulation resistor under test is connected to a reference resistor. A prototype...
The present contribution is focused on the measurement of the degradation induced in the case of two splitters and two attenuators used in optical fiber communication systems, under gamma and neutron irradiation. The measurements were carried out at specific wavelengths ( λ = 1310 nm and λ = 1550 nm) or over a spectral band ( λ = 1510 - 1620 nm), in order to evaluate the wavelength dependence of the phenomena. These components were also tested as it concerns the changes of the polarization state of optical radiation they guide. A second investigation was performed on the degradation of the...