G. M. Rocha, G. A. Kyriazis
The manufacturers specify the long term stability of their measuring standards. This parameter is sometimes the largest uncertainty contribution to the overall uncertainty of the standard. An automated system for the evaluation of the stability of measuring standards using Bayesian statistics was developed. For several standards it was verified that the stability estimate is much smaller than the value specified by the manufacturer. The software for data analysis was implemented in language C in the environment LabWindows/CVI.
TC4 Symposium 2004
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· 2004
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Theodore Kotsilieris, Stelios Kalogeropoulos, George Karetsos, Vassilis Loumos, Eleftherios Kayafas
Nowadays we witness a growing interest for the efficient management of the QoS delivered by the service providers to the Internet users and the usage of SLAs. In such an environment the need to maximise customer satisfaction and reliability and consequently, the deriving obligation to quantify and measure service functions becomes apparent. As traditional centralized NMS manager-agent approach has stretched to its limits, we propose a way of bringing together the static nature of SNMP protocol with the Mobile Agent Technology (MAT) in IP network. In order to address lack of quality of...
TC4 Symposium 2004
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S. Kalogeropoulos, G. Karetsos, A. Anagnostopoulos
The results of the research in the area of Mobile Agent Technology (MAT) have demonstrated the utility of this paradigm in building a wide range of distributed applications and systems. In the past few years, we have witnessed an enthusiastic interest in MAT and plenty of research activities have been carried out. Despite this effort, a number of issues concerning mainly the performance optimisation of agent-based applications are still open. In this paper, we investigate the problem of optimising the number of mobile agents used in an agent-based application in order to improve its...
TC4 Symposium 2004
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Heikki Jokinen, Risto Ritala
Modern industrial production processes are rich sources of measurement data, acquired in many forms and time periods. The integration of different forms of data and information has become more and more important in process industry. Decisions needed in managing processes in an optimal way force us to utilize the information in a way that maximizes its value. This paper discusses the value assessment of measurements and measurement information in large industrial systems. In particular, probabilistic description of information and the value of uncertainty and information in measurements...
TC4 Symposium 2004
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Andrea Condarcuri, Domenico Grimaldi, Antonino Panella
The Distributed Measurement Laboratory (DML) is an heterogeneous system and the workload evaluation is an important aspect to support the performance management strategies in the case the specific requirements must to be respected. The paper describes the method to evaluate the workload of the cooperating hardware equipments of the DML, in particular: (i) the connecting networks, and (ii) the PCs. In this manner useful indexes are achievable to monitor the functioning conditions of the whole DML. The proposed method is based on three different tools known and tested in literature. The first...
TC4 Symposium 2004
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Călin Ciufudean, Constantin Filote, Adrian Graur, George Mahalu
In this paper we focus on the problem of scheduling time-critical data flow over a measuring tree network. We assume that data are operated in discrete time and their arrival and deadline processes are arbitrary. Our goal is to determine a policy which transmits data with minimum extension time at every node (every link) in a tree network. The models existing in the literature do not consider simultaneous performance of various hardware components of a complex system. When a hardware component of the system fails, the system reconfiguration is often less than perfect. On this assumption we...
TC4 Symposium 2004
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J.F.M.L. Mariano, Helena Ramos
Some results on the validity of Widrow’s model of quantizing sinusoidal signals in a uniform quantizer are presented. Sripad and Snyder’s formulation is used to derive a general equation for the probability density function of the quantization noise, for a generic sinusoidal signal, which is applied to different types of sinusoids. The equations obtained in this way are numerically evaluated to characterize the quantization noise by means of its average and variance. In this calculation, a novel method to accelerate the series convergence has been used. The results obtained provide a...
TC4 Symposium 2004
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Leopoldo Angrisani, Mauro D’Arco, Rosario Schiano Lo Moriello, Michele Vadursi
Data Acquisition Systems (DAS) play a fundamental role in a lot of modern measurement solutions. One of the parameters characterizing a DAS is its maximum sampling frequency. As well known from Nyquist theorem, for a correct digitization of analog signals, sampling frequency must be greater than a limit value, related to signal bandwidth. With regard to band-pass signals, which are very common in telecommunications, it is possible to single out some separated ranges of licit sampling frequencies that are significantly lower than such threshold. But, how to choose the sampling frequency...
TC4 Symposium 2004
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Tomas Andersson, Peter Händel
Multi-sinewave test methods require algorithms for multiple-tone parameter estimation. There exist a vast amount of imeko_proceedings on the topic. This paper presents a generalization of the IEEE four-parameter sinewave fit algorithm suitable to handle data comprising multiple sinewaves. The proposed method directly estimates the 3 p + 1 parameters of a p -tone model. The algorithm is analyzed numerically with emphasize on its convergence properties and statistical efficiency. The initialization of the algorithm is of major importance and an attempt to formulate a proper initialization...
TC4 Symposium 2004
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Pier Andrea Traverso, Domenico Mirri, Gaetano Pasini, Gaetano Iuculano
A novel family of windows are proposed for digital spectrum analysis and the main figures of merit compared to those associated with both well-known and state-of-the-art windows available in the literature. The elements of the family, which are obtained by means of successive linear convolutions between elementary rectangular windows, present a very good side-lobe behaviour if a moderately high order of convolution is considered and allow for a strong reduction of the spectral leakage effect at the output of the analysis. The growth of the main-lobe within the spectrum of the proposed...
TC4 Symposium 2004
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· 2004
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