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Resumo: A narrativa de Rousseau sobre a origem do Estado foi retomada nos últimos séculos por diversas tradições, fazendo-se notar no seio do iluminismo escocês e nos trabalhos de Engels. James Scott, em seu recente livro Contra o grão, de 2017, ecoa algumas teses de Rousseau. Dentre tantos pontos de convergência, três se destacam e serão analisados no decorrer deste artigo: i) de um lado, a variedade dos modos de ser e de se relacionar com a natureza dos povos sem Estado, a idade de ouro dos bárbaros; de outro, a estratificação dos povos sob o Estado, o empobrecimento dos agricultores cerealistas; ii) as condições ecológicas raras e especialíssimas favoráveis à emergência do aparelho estatal, em oposição às dificuldades de se formar o Estado, em regiões de abundância naturais, donde se faz necessário estabelecer a hipótese de mudanças climáticas que alteram as condições de existência; iii) e, por fim, a importância dos grãos para o processo civilizatório, isto é, a afinidade entre economia agrária de cereais e Estado.

Sustainability has gained significant relevance in every sector. In particular, in information and communication technology (ICT), there is growing attention towards this aspect. Measurement systems are arguably one of the numerous manifestations of ICTs, and they are virtually ubiquitous in the current 4.0 Era. This pervasiveness leads to ponder over the effect that measurement systems have on the environment. However, to date, no study addressed the sustainability of measurements and their impact on the environment. This work proposes a first methodological approach for the modeling and assessment of environmental sustainability of measurements as part of ICT. In particular, an iterative approach is presented to assess the impacts of the measurement as a whole. This also paves the way to unveil the relation between measurement sustainability and measurement uncertainty. As representative examples, in this work, two practical scenarios are considered: (i) measurement of resistances with a Wheatstone bridge and (ii) measurement of emissions from an internal combustion engine.

The digital storage oscilloscope (DSO) has a vital role in measurement practice, since its resourcefulness fits both general purpose aims and requirements of more specific applications. A deep knowledge of DSO operation principles and available features is fundamental for technicians to best exploit the possibilities of the instrument. Operation principles regard digitization, acquisition, processing and visualization of the input waveform and concern a number of issues. For performant DSO digitizing systems, one of the most relevant issues is the calibration of the time-interleaved structure at the very heart of the instrument. Unfortunately, the calibration techniques adopted by the manufacturers are never disclosed in plain form with application notes or demos, and limited information can be read from patents, if available. In this article, the state-of-the-art of DSO technologies is reviewed; a general framework to face the calibration issue in time-interleaved systems, which is based on the generalized sampling theorem, is presented; and the case of some DSOs, which require special calibration approaches, implemented through the analysis of the input-output crosscorrelation of the individual acquisition channels, is discussed. Concluding remarks underline the value of the contribution, that provides a significant example of how more ideal acquisition channels can be realized by the combination of analog circuitry with digital processors.

A theoretical framework to implement multi-sensor data fusion methods for kinematic quantities is proposed. All methods defined through the framework allow the combination of signals obtained from position, velocity and acceleration sensors addressing the same target, and improvement in the observation of the kinematics of the target. Differently from several alternative methods, the considered ones need no dynamic and/or error models to operate and can be implemented with low computational burden. In fact, they gain measurements by summing filtered versions of the heterogeneous kinematic quantities. In particular, in the case of position measurement, the use of filters with finite impulse responses, all characterized by finite gain throughout the bandwidth, in place of straightforward time-integrative operators, prevents the drift that is typically produced by the offset and low-frequency noise affecting velocity and acceleration data. A simulated scenario shows that the adopted method keeps the error in a position measurement, obtained indirectly from an accelerometer affected by an offset equal to 1 ppm on the full scale, within a few ppm of the full-scale position. If the digital output of the accelerometer undergoes a second-order time integration, instead, the measurement error would theoretically rise up to 12n(n+1) ppm in the full scale at the n-th discrete time instant. The class of methods offered by the proposed framework is therefore interesting in those applications in which the direct position measurements are characterized by poor accuracy and one has also to look at the velocity and acceleration data to improve the tracking of a target.

La nota presenta lo sviluppo e la calibrazione di un sistema innovativo per la misura del contenuto d’acqua in terreni parzialmente saturi, basato sulla spettroscopia d’impedenza. Tale tecnica, relativamente recente e poco comune in applicazioni geotecniche, permette di caratterizzare un campione di terreno a partire dalle sue proprietà elettriche, determinate applicando una tensione alternata e misurando l’intensità di corrente nel campione per valori di frequenza compresi nell’intervallo [500 Hz - 50 kHz]. L’impedenza del mezzo, dovuta sia alla resistenza opposta al passaggio di corrente sia alla reattanza, ovvero alla capacità di immagazzinare e cedere energia, dipende dal contenuto d’acqua del campione di terreno. La sperimentazione di laboratorio discussa in questa nota è volta a costruire una funzione di calibrazione del sistema di misura. I risultati preliminari mostrano un adeguato grado di ripetibilità delle misure e suggeriscono l’esistenza di una correlazione monotona tra il modulo dell’impedenza e il contenuto d’acqua gravimetrico.

Innovative digitizers exploiting mixing, filtering and processing (MFP) operations can grant ultra-high bandwidth and sampling rate. Their operation combines analog processing stages with a digital signal processing stage, where massive operations are performed to obtain the digital representation of the input signal. In fact, the samples returned by the analog-to-digital converter (ADC) consist of a transformed, namely mixed and filtered, version of the input, which shall be processed in the digital domain to reconstruct the input signal. The digital processing is also designed to attain streamline calibration, which provides both the removal of non-ideal effects, such as mismatches between individual channels, and the improvement of the frequency response flatness. Calibration strategies represent an asset of manufacturers’ know-how, since the performance of the digitizer largely depends on the effectiveness of the calibration process. Gain equalization and aliasing removal are performed in the digital domain by finite impulse response (FIR) filtering of the ADCs’ outputs. A general method for the identification of the calibration filters, and their translation into algorithms for MFP digitizers using 2, 4, or any number of channels, is here proposed. Functional-level and circuit-level Cadence Virtuoso simulations in an STMicroelectronics Si-Ge heterojunction bipolar transistor (HBT) process are also carried out to evaluate the performance of the proposed method through a comparison between the digital representations of the signals obtained with and without calibration.

Designing and implementing a remote laboratory has long been a professional job, carried out by experts working in synergy with teachers. Nowadays, thanks to the availability of advanced tools, the implementation can be assigned as a student project related to advanced measurement and automation classes. The development of the project happens to have an important educational validity, since it allows the student to get familiar with principles and technologies that characterize intelligent manufacturing and smart environments, as central elements of Industry 4.0. In particular, the student has the opportunity to increase knowledge of Internet technologies that more and more often are substituting for the proprietary solutions, previously adopted in the industry for process monitoring and automation.

An approach for time and frequency measurements based on the use of data acquisition systems equipped with elementary processing capabilities is proposed. The bases of the proposal and its features that, in principle, allow measurements characterized by very fine resolution, are illustrated theoretically; preliminary results are finally given.

Digital Storage Oscilloscopes (DSOs) conjugate high performance with large number of features and flexibility. The basic structure, based on fast Analog to Digital Converter (ADC) and memory, is augmented with several components for channel matching and bandwidth improvement, and processors that provide visualization, frequency processing, jitter and stability measurement, etc. Unfortunately, fine resolution in sample rate selection is not available, such that for several applications the user must run complex measurement procedures that require data download and offline processing. The paper proposes a dedicated digital circuit that offers fine control of the time-base by real time downsampling the input stream at an almost arbitrary sampling rate. The proposed circuit implements a series of operations involving real-time data filtering, defragmentation and packing, which are not considered by alternative approaches, like those based on polyphase filters, that offer very limited choices for the sampling rate. The circuit is designed to work in conjunction with the highest performance DSOs that use a multichannel architecture. Design rules for circuit design are provided together with implementation results in 14nm FinFET technology. When designed for an architecture with 64 channels with 8bit input samples the circuit works in real time with a sampling rate of 220 GSps running at 3.42 GHz, with a silicon footprint of 0.17 mm2 and a power dissipation of 0.85W.

Resumo: Arthur Schopenhauer possui uma concepção acerca da natureza do conceito que atravessa o seu pensamento, desde o início de sua produção filosófica. Inicialmente abordado a partir de sua acepção racional abstrata, em O mundo como vontade e como representação, o conceito adquire traços mais profundos em função do sentimento (Gefühl). O conceito “não-conceito” sentimento determinará os rumos da filosofia de Schopenhauer, ao evidenciar os limites da linguagem. A linguagem filosófica, por consequência, exprime um paradoxo, pois pretende expressar em linguagem abstrata um conteúdo concreto cuja natureza não pode ser por ela determinado. Por ser um construto conceitual abstrato, a linguagem filosófica possui um estatuto ontológico secundário e, portanto, incompleto, em relação ao conteúdo da realidade concreta. Este artigo pretende mostrar que os sentimentos são, nesse sentido, o meio não conceitual que esclarece a própria natureza dos conceitos e, por consequência, a via não-filosófica que paradoxalmente melhor expressa o conteúdo da filosofia. No registro do sentimento, Schopenhauer reconhece na linguagem musical o âmbito de justificação adequado da linguagem filosófica. Abstract: Arthur Schopenhauer has a notion about the nature of the concept that runs through his thinking since the beginning of his philosophical production. Initially approached from its abstract rational meaning, in The world as will and representation, the concept acquires deeper traces from sentiment (Gefühl). The “non-concept” concept of sentiment will determine the direction of Schopenhauer”s philosophy by highlighting the limits of language. The philosophical language, therefore, expresses a paradox, since it intends to manifest, in abstract language, a concrete content, whose nature cannot be determined by it. As an abstract conceptual construct, philosophical language has a secondary and, thus, incomplete ontological status in relation to the content of concrete reality. Sentiments are the non-conceptual medium that clarifies the nature of concepts itself, and, consequently, the non-philosophical way that paradoxically best expresses the content of philosophy. In the recording of sentiment, Schopenhauer recognizes in musical language the proper justification scope of philosophical language.

An arbitrary waveform generator architecture that exploits multiple DAC cores to increase the sample rate with respect to AWG architectures based on an individual DAC is proposed. The processing operations necessary to distribute the waveform samples between the DAC cores are illustrated. The preliminary results highlighting the performance expected from the proposed architecture are shown.

The scope of the present work is to illustrate the main idea and the realization process at the basis of Flying Outfit for Control of Unsafe Seagulls FOCUS project. The project has been realized by a consortium of companies in collaboration with the University of Naples "Federico II" and CeSMA (Centro Servizi Metrologici e Tecnologici Avanzati) center. The main objective of the research is the definition of a process able to provide a supply of services for the management of coexistence problems between human and unsafe seagulls by means of small remotely piloted aircraft. The main purpose is to overheat the seagull eggs in the nest by means of a microwave device so they are no longer fertile. This is considered as an acceptable way to reduce the risk of unsafe interaction among seagulls and humans. The paper describes the different steps needed for the realization of the mission and the small unmanned aircraft used for the monitoring, operating on the nest, and collecting of gull fecal samples. Finally, the software developed for image detection of seagulls nest is presented.

Large scale wildfire events that occurred around the world involved a massive loss of animal lives, with a consequent economic impact on agricultural holdings and damages to ecosystems. Preparing animals for a wildfire evacuation requires an extra level of planning, preparedness and coordination, which is missing in the current practice. This paper describes a conceptual framework of an ICT system implemented to support the activities of the Regional Veterinary referral Center for non-epidemic emergencies (CeRVEnE) in the Campania Region for the twofold objectives. On the one hand, it realizes the monitoring of the wooded areas under risk of fire in the so-called &ldquo, Mount Vesuvius&rsquo, red zone&rdquo, On the other hand, it determines the OPtimal Evacuation Route for Animals (OPERA) in case of fire, for each of the reported animal species living in the mentioned red zone. The main innovation of the proposed system lies in its software architecture that aims at integrating a Distributed Sensor Network (DSN), an ad-hoc software to generate timely simulations for fire risk modeling, and a GIS (Geographic Information System) for both the activities of web mapping and OPERA definition. This paper shows some effective preliminary results of the system implementation. The importance of the system mainly lies in its accordance with the so-called &ldquo, Foresight approach&rdquo, perspective, that provides models and tools to guarantee the prevention of systematic failure in disaster risk management, and becomes moreover critical in the case of Mount Vesuvius, which hosts a unique combination of both animal and anthropic elements within a delicate natural ecosystem.

Experimental practice in laboratory is a fundamental teaching issue in electrical and electronic measurement courses. Unfortunately, crowded classes, along with limited universities resources, do not allow to meet this need through actual laboratory sessions. In such a context, remote laboratories have proved to be an excellent solution. A significant added value, in a remote laboratory, is the possibility to modify the test circuit, in order to vary the type of experiment. The authors suggest, in the paper, to overcome t he considered limitations by integrating inside the remote laboratory suitable devices that can be remotely configured, i.e. a Field Programmable Analog Array (FPAA). FPAA is exploited for emulating the behavior of a large variety of analog circuits, thus making it possible for users, either students or technicians, to select the desired test circuit and carry out the experiment from home.

Fine resolution selection of the sample rate is not available in digital storage oscilloscopes (DSOs), so the user has to rely on offline processing to cope with such need. The paper first discusses digital signal processing based methods that allow changing the sampling rate by means of digital resampling approaches. Then, it proposes a digital circuit that, if included in the acquisition channel of a digital storage oscilloscope, between the internal analog-to-digital converter (ADC) and the acquisition memory, allows the user to select any sampling rate lower than the maximum one with fine resolution. The circuit relies both on the use of a short digital filter with dynamically generated coefficients and on a suitable memory management strategy. The output samples produced by the digital circuit are characterized by a sampling rate that can be incoherent with the clock frequency regulating the memory access. Both a field programmable gate array (FPGA) implementation and an application specific integrated circuit (ASIC) design of the proposed circuit are evaluated.

The design and implementation of a time base system that allows arbitrary selection of the sample rate in digital storage scopes with very fine frequency resolution is presented. The proposed solution relies on a suitable memory management strategy and a short digital filter with dynamically generated coefficients. It represents an alternative to the use of external clocks, which, due to the bandwidth restriction of the external path, can effectively be used to control the sample rate only on a limited portion of the whole range. The value of the proposed solution consists of widening the functionalities of general-purpose instruments such as digital storage oscilloscopes (DSOs) with limited impact on precision.

The performance parameters defined in the IEEE Standard 1057–2007 do not specify the standard uncertainty of the reconstruction levels of digitizing waveform recorders. Not knowing the standard uncertainty of the reconstruction levels affects, in turn, the evaluation of the uncertainty of a number of measurement approaches, based on digital signal processing techniques, which utilize the data collected by a digitizing waveform recorder as the input data. A method to evaluate the uncertainty of memoryless waveform recorders embedded in off-the-shelf digitizing oscilloscopes is proposed here. The method is based on an experimental approach that can be carried out anytime the input signal is repetitive, the frequency response of the oscilloscope can be considered flat, and the dynamical effects are negligible. To qualify the proposed method, the uncertainty estimation obtained by applying it in several experiments is compared with that gained by means of a B-type evaluation.

Measuring signals in ultra-fast electronic systems requires high-end digital oscilloscopes characterized by extremely large analog bandwidths, up to 100 GHz, and digitization capabilities at least up to the corresponding Nyquist rate, i.e. 200 GS/s or above. This performance can be achieved by means of architectures that implement suitable methodologies, based on synchronous time interleaving, digital bandwidth interleaving, or hybrid approaches merging and exploiting both of the previous concepts. Each of these architectures typically includes a number of innovations, concerning both methods and hardware solutions, which are either covered by patents or classified. The paper presents the architecture of an original high-speed digitizer that exploits frequency conversion and time interleaving techniques. Thanks to the use of 4 time-interleaved channels, each one consisting of a state-of-the-art sampler and an ADC, the proposed solution can increase fourfold the analog bandwidth with respect to the individual ADCs, achieving noise reduction with respect to traditional time interleaved architectures.

Virtual instruments let the user define custom measurement approaches to cope with specific goals. The use of virtual instruments also raises an important issue, which concerns the evaluation of the uncertainty of the measurement results. To face this issue, a change in the praxis currently adopted to interpret the analog-to-digital converter (ADC) datasheets released by the manufacturers for documenting their products seems necessary. This change should be the consequence of modifications and/or integrations of the standard documents adopted by the same manufactures, by the way proposed by the scientific community. Modifications and/or integrations should assure the compliance between parameters and methods for ADC testing and recommendations contained in the guide to the expression of uncertainty in measurement.

A novel digital signal processing-based method for phase noise measurement on sinusoidal signals is proposed. The method obtains the power spectral density of the phase noise by Fourier transforming its autocorrelation function. The autocorrelation function of the phase noise is in turn derived from the cyclic complementary autocorrelation function of the analytical version of the sinusoidal signal under test. The method proves that, taking advantage of the cyclostationarity properties of the signal under test, it is possible to improve the sensitivity in phase noise measurements by diminishing the effects of the instrumentation noise, which mainly limits the performance of the majority of the digital processing-based approaches.