Yoshito Isei, Tatsuro Honda, Kenichi Akahane, Hideyuki Takahashi
DEVELOPMENT OF REFRACTORY THICKNESS METER FOR TORPEDO LADLE CAR

To inspect the refractory of torpedo ladle car at high temperature is effective in expanding its service life and reducing its maintenance cost, preventing metal break out. As to metal impact area, the refractory thickness could not be inspected by thermal analysis of outer steel shell. The refractory thickness meter was installed at torpedo repair shop for evaluating its measurement stability and refractory thickness measurement accuracy. It has two surface profile maters using laser rangefinder equipped with two tilt stages, facing each other. It measures the inner refractory profile and the outer steel shell profile at one time to calculate the accurate refractory thickness without influence of the outer shell deformation. After 90 minutes from discharging molten iron, it could achieve stable measurement without the influence of fume and heat haze, and could measure the refractory thickness with a good accuracy of 7.3mm (1 sigma).

Clemens Elster, Sascha Eichstädt, Alfred Link, Thomas Bruns
REAL-TIME DYNAMIC ERROR COMPENSATION OF ACCELEROMETERS BY DIGITAL FILTERING

The output signal of an accelerometer typically contains dynamic errors when a broadband acceleration is applied. In order to retrieve the applied acceleration, post-processing of the accelerometer's output signal is required. To this end, we propose the application of a digital filter. We describe the construction of an appropriate filter and consider the uncertainty associated with the filtered output signal. Explicit formulae can be employed to calculate both, the filtered output signal and its associated uncertainty, in real-time. We illustrate the need and benefit of the proposed approach in terms of an example.

Maurizio Caciotta, Sabino Giarnetti, Fabio Leccese
HYBRID NEURAL NETWORK SYSTEM FOR ELECTRIC LOAD FORECASTING OF TELECOMUNICATION STATION

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 big telecommunication operator has been tested.
The total forecast has been obtained combining the two components. The forecasting accuracy for a whole year test data is around 2%. Some problem exists in the forecasted load of summer time.

Ignacio Lira, Dieter Grientschnig
BAYESIAN ANALYSIS OF A CALIBRATION MODEL

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 approaches produce the same final results if the prior function to be used in the second approach is derived from that applicable to the first approach. By following this procedure, both prior functions are assured to encode the same initial information.

Takashi Yamamoto, Masayuki Yamamoto, Kensuke Miyahara, Tatsuya Ishibashi
INFLUENCING PARAMETERS OF EQUIVALENT INDENTATION TEST

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 equivalent indentation test. In this report, we discuss some major factors that can influence equivalent indentation depth, including the geometrical shape of the indenter used and the load ratio "r" (preliminary-to-total test force ratio).
As a result, it is found that the results of the equivalent indentation test using a pyramidal or conical diamond indenter are mutually convertible, and that the difference in equivalent indentation depth among Vickers, Berkovich, and Modified Berkovich indenters, which are probably the most popular indenters for the test, is as small as around ±1%. From our experiments, it is also confirmed that the equivalent indentation test is less susceptible to indenter tip wear than the instrumented indentation test.
Understandably, equivalent indentation depth is influenced by load ratio r, but the conversion formula developed by introducing an appropriate model into load curves is found to be effective for mutual conversions of the values of equivalent indentation depth at different load ratios for a practical range of applications.