1,721,088 research outputs found
Fundamentals of hard and soft measurement: a pragmatic and structural perspective
No full textThis chapter describes a measurement framework that can be used to analyze the major aspects associated to hard and soft measurements. The framework provides a discipline for planning and executing a measurement and for interpreting experimental outcomes. The application of this framework to the assessment of research quality has evidenced the need for such disciplined reasoning when issues of measurability and metrological model identifiability become evident. This example has highlighted that information producing processes, such as measurement and assessment, usually have different features. Assessment differs from measurement in at least three aspects: uncertainty not explicitly evaluated, reference scale implicitly defined, comparison with standards performed in a subjective, or only partially inter-subjective, way. The usage of the measurement framework eases reasoning about the various steps, both formal and informal, that could be followed to enhance the objectivity and the inter-subjectivity of any v-assignment and of its results
An Adaptive Real-Time Spectrum Analysis Architecture
No full textAn architecture for adaptive real-time spectrum analysis of multi-frequency waveforms is presented. The adaptation strategies implemented ensure that system performances are at any time optimal, or at least near-optimal, for the aim of minimising measurement time. A new measurement algorithm for high-accuracy analysis in the frequency domain, which provides the basis for efficient adaptation, is introduced and an assessment is given of its accuracy. The system, based on this architecture, provides high-accuracy results and near-minimum measurement delay for input frequencies up to 20 kHz
DITHER SIGNAL EFFECTS ON THE RESOLUTION OF NONLINEAR QUANTIZERS
No full textThe consequences of dithering on nonlinear quantizers are analyzed. A model of the nonlinear quantizer is considered, and a model of the same quantizer with dither is proposed. By means of this approach, relationships are given for the total quantization error in the case of discrete binary, uniform, and Gaussian dither signals
Performance of stochastic quantizers employing nonlinear processing
No full textDithered quantizers are often employed in numerical instrumentation to improve the resolution and accuracy of the analog-to-digital converters used. To this aim, linear post-processing is usually performed on the quantized samples. In the paper, a different processing scheme is described that exhibits a nonlinear behavior. The characteristics of both linear and nonlinear topologies are analyzed, and expressions are given for the quantization error average and variance that make possible the comparison of the two algorithms. It is shown that the nonlinear one provides better performance, so that it can be employed to further improve the estimation capability of a dithered quantizing system. The reported results have been validated by means of meaningful simulations
Instrumentation and Measurement in Communication Systems
No full textThe demand for ubiquitous connectivity is challenging the physical constraints placed upon current communication systems. In addition, customers expect higher and higher quality from their service providers. Consequently, equipment manufacturers are required to produce systems that can be quickly deployed and provide bandwidth-efficient communications. To meet this goal, instrumentation and measurements play a fundamental and invaluable role.
At early stages of equipment development, rigorous testing is performed to both assess system functionality and performance and ensure system interoperability. Moreover, the increasingly complex nature of communication signals is placing additional pressure on design teams, already faced with tight project deadlines. Not only must the developer perform conformance testing; he/she must also quickly infer from measurement results root causes of possible technical problems.
The strategic importance of measurements in the field of communication systems is corroborated by the significant increase in the number of papers on this topic - both submitted and accepted - experienced by IEEE Transactions on Instrumentation and Measurement (TIM) in recent years. Unfortunately, many submitted papers are rejected because they fall clearly outside the journal scope. This fact motivated us – as researchers in the field—to write this paper to specify what can be considered an instrumentation and measurement (I&M) technical contribution in the field of communication systems
- …
