Digital Integrator Research Articles

Economic assessment of the effects of the introduction of digital platforms for the integration of participants in mixed (multimodal) freight transport (based on rail transport)

Purpose: to reveal and describe the functionality, main services and opportunities for participants in the transportation process (cargo owners, operators, service companies) to connect to a digital integrator – a single platform “Electronic trading platform “Freight Transportation” (ETP FT), to substantiate the methodology for the economic assessment of the effects of the introduction of digital platforms for the integration of participants in freight mixed (multimodal) transportation (based on rail transport); calculate the individual economic effects of integration on the platform for various participating parties. Methods: supply chain analysis, evaluation of time-saving effects, analysis of logical flow processes and operations. Results: a methodology has been developed to assess the economic effects of integrating transport market participants into a digital platform, which consists in evaluating individual cost savings elements for a specific platform participant, including: by converting the document flow to an electronic format, by minimizing the cost of storing paper forms of documents, the cost of shipping, forwarding documents and related cash gaps, saving time and shortening financial cycles during the transition to electronic signing of documents and acceptance of electronic forms of documents by participants. Recommendations: The materials are addressed to specialists of companies participating in the transport and logistics market, IT directors and specialists, and all stakeholders interested in the development of the digital ecosystem.

Managerial capabilities as facilitators of digital transformation? Dynamic managerial capabilities as antecedents to digital business model transformation and firm performance

Digital business model transformation (DBMT) necessitates new managerial capabilities, yet the existing literature lacks an empirical understanding of managerial capabilities as antecedents to strategic change and firm performance. This paper builds on dynamic managerial capabilities theory to argue that managerial human capital—composed of leadership and entrepreneurial skills—is a critical facilitator of DBMT and resultant firm performance. Further, the research model proposes that managers' social capital and cognition positively moderate the relationship between human capital and DBMT. The study's findings from a sample of German Industry 4.0 firms provide new insights into the significance of managerial capabilities in a digital economy. This study advances management literature by demonstrating that the benefits of managers' human capital for DBMT are contingent on its form: entrepreneurial skills facilitate digital transformation integral for firm performance, while leadership skills have no impact on firm performance—neither directly nor indirectly through DBMT. Thus, this study provides strong evidence of the importance of entrepreneurial skills in driving DBMT to increase firm performance. Further, the findings offer a nuanced account of the interrelationships between dynamic managerial capabilities, revealing that higher levels of social capital and lower levels of cognition increase the positive effect of entrepreneurial skills on DBMT. This study altogether reaffirms the significance of managers' dynamic capabilities for strategic change enabled by DBMT and their performance benefits, yet it reveals that the effect mechanisms differ from those found in nondigital research settings.

A Duty-Cycled Integrated-Fluxgate Magnetometer for Current Sensing

This article presents a duty-cycled integrated-fluxgate (IFG) magnetic-to-digital converter for contactless current sensing. While previous works have proven high linearity, low noise, and low offset capabilities of fluxgate sensing, this work focuses on low energy operation. The mixed-signal front-end design enables energy-efficient duty cycling with a 13-bit digital integrator to retain the last converged output during sleep mode and resume searching in its vicinity upon wake up. The system achieves a ±2.4 mT measured range of magnetic fields for indirect current measurement. The hierarchical search modes achieve <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10\times $ </tex-math></inline-formula> faster convergence than analog implementations. The faster readout with a peak sampling rate of 770 kS/s translates to lower compensation energy per sample. The 3-dB bandwidth of 125 kHz is 67% higher than prior IFG art, with competitive 500-nT rms noise. The test chip fabricated in 250-nm CMOS technology consumes the lowest power of known IFG works. It can be duty-cycled to save energy in low-bandwidth applications or run at peak bandwidth for low latency.

Mechanical Fault Prognosis through Spectral Analysis of Vibration Signals

Vibration signal analysis is the most common technique used for mechanical vibration monitoring. By using vibration sensors, the fault prognosis of rotating machinery provides a way to detect possible machine damage at an early stage and prevent property losses by taking appropriate measures. We first propose a digital integrator in frequency domain by combining fast Fourier transform with digital filtering. The velocity and displacement signals are, respectively, obtained from an acceleration signal by means of two digital integrators. We then propose a fast method for the calculation of the envelope spectra and instantaneous frequency by using the spectral properties of the signals. Cepstrum is also introduced in order to detect the unidentifiable periodic signal in the power spectrum. Further, a fault prognosis algorithm is presented by exploiting these spectral analyses. Finally, we design and implement a visualized real-time vibration analyzer on a Raspberry Pi embedded system, where our fault prognosis algorithm is the core algorithm. The real-time signals of acceleration, velocity, displacement of vibration, as well as their corresponding spectra and statistics, are visualized. The developed fault prognosis system has been successfully deployed in a water company.

Design and Optimization of Enhanced Magnitude and Phase Response IIR Full-Band Digital Differentiator and Integrator Using the Cuckoo Search Algorithm

Design of full-band infinite impulse response (IIR) digital differentiator (DD) and digital integrator (DI) based on the L_k-norm and the min-max optimality criteria have been demonstrated in literature. However, the designed IIR DDs and DIs using these criteria do not have linear phase or have unsatisfactory magnitude response. In this paper, a novel approach to design, optimize and improve the magnitude response and the linearity of the phase response of IIR DD and DI using the cuckoo search (CS) optimization algorithm is proposed. The proposed approach is based on a varied L_<i>k</i>-norm where <inline-formula> <tex-math notation="LaTeX">$k$ </tex-math></inline-formula> linearly increases with the number of the frequency samples between the values 1 and 2. The design and optimization of DDs and DIs are carried out using the CS optimization method due to its simplicity, efficiency, and robustness in solving general multidimensional optimization problems. The performance of the designed DDs and DIs using the proposed approach is compared with designs based on different criteria and algorithms available in literature. The comparison shows that the designed DDs and DIs based on the proposed approach have better phase responses and better or at least comparable magnitude responses compared to those of DDs and DIs designed using other methods in the literature.

Development of a Transient Magnetic Field Sensor Based on Digital Integration and Frequency Equalization.

Transient magnetic field sensors are used in various electromagnetic environment measurement scenarios. In this paper, a novel magnetic field sensor based on a digital integrator was developed. The antenna was a small B-DOT loop. It was designed optimally for the simulation. The magnetic field signal was digitally integrated with the improved Al-Alaoui algorithm, resulting in less integration error. To compensate for the bandwidth loss of the optical fiber system, we specially designed an FIR (finite impulse response) filter for frequency compensation. The circuit was described, and the transimpedance amplifier was specially designed to ensure the low noise characteristic of the receiver. The sensitivity of the sensor was calibrated at 68.2 A·m−1/mV, the dynamic range was 50 dB (1–300 kA/m), the linear correlation coefficient was 0.96, and the bandwidth was greater than 100 MHz. It was tested and verified under the action of an A-type lightning current. The sensor exhibited high-precision performance and flat amplitude-frequency characteristics. Therefore, it is suitable for lightning positioning, partial discharge testing, electromagnetic compatibility management, and other applications.

Fast lock-in amplifier electrochemical impedance spectroscopy for big capacity lead-acid battery

Big capacity (>4000 Ah) lead acid battery is necessary to important emergency power system. Electrochemical impedance spectroscopy (EIS) of the battery is weak. Low frequency Digital Lock-in Amplifier (DLA) needs long-term sampling. Fast Fourier Transformation (FFT) needs whole number periods sampling. This paper suggests a Fast Lock-in Amplifier (FLA). It takes place of low pass filter with linear average definite digital Integrator. The FLA can output at short-term and partial period sampling. Its result is a fast linear interpolation of FFT. Results of FLA and FFT are identical at whole number periods sampling. The proposed method is verified by Valve-Regulated Lead-Acid (VRLA) battery (4200 Ah) aging tests. Microcontroller runs the proposed algorithm.

Semi-Active Scissors-Seat Suspension With Magneto-Rheological Damper

A cab seat suspension with a magneto-rheological (MR) fluid damper is introduced in this paper. A unified-format model for the MR damper is proposed to describe the dynamic characteristics of the MR damper. Also, a simple force-inverse model and a viscous damping tracking model are used for the coil current solution. A digital integrator and an extended Kalman filter are respectively adopted to obtain the vibration velocity of the chair frame and the relative motion velocity of the MR damper piston. A new skyhook control base with viscous damping tracking is applied to the semi-active seat suspension. In the simulation, compared with passive seat suspension under different displacement excitation (2, 4, 6, 8 Hz-sine, and random), the acceleration root mean square of the seat suspension with the MR damper is reduced by 52.2%, 32.2%, 41.3%, 50.8%, and 34.6%, respectively. In the experiment, the acceleration root mean square is reduced by 11.2%, 41.2%, 45.8%, and 31.5%, respectively under different displacement excitation (2, 4, 6, and 8 Hz-sine).

Estimation of the foliar area of jambolão (Syzygium cumini (L.) Skeels) by different methods.

The jambolan as it is popularly known as Syzygium cumini (L.) Skeels, is of Indian origin. Studies in various areas require estimation of leaf area over the growing cycle. Leaf area is an important aspect in the analysis of photosynthetic efficiency of plants. The objective of the present study was to evaluate S. cumini leaf area determination methods based on measurements by caliper, leaf area integrator and previous image calibration in ImageJ Software, comparing both methodologies. The present study was developed at Mato Grosso State University Carlos Alberto Reys Maldonado - UNEMAT, Alta Floresta campus - MT. Fifty leaves were analyzed, which were numbered from 1-50 in length (C) and width (L) with the aid of a digital caliper and leaf area integrator (Leaf area integrator LI-COR 3100), for measuring leaf area (AF), after the sheets were scanned on an HP Photosmart C4680 flatbed scanner and processed using ImageJ software. Given the data found, it was found that the method used via digital imaging was accurate and showed a high correlation with manual measurement, indicating that the morphological characteristics of leaf area, length and width of Jambolão leaves can be estimated through analysis and analysis. Digital image processing.

An Analog-Proportional Digital-Integral Multiloop Digital LDO With PSR Improvement and LCO Reduction

This article presents a low-dropout regulator (LDO), with analog-proportional (AP) and digital integral (DI) controls. The design concerns are discussed at first, on how to improve the load transient response, enhance the power supply rejection (PSR), and reduce the limit cycle oscillation (LCO). For a good output dc accuracy, the DI section is implemented with shift-register-based coarse- and fine-tuning loops. Meanwhile, the AP section, based on a low-supply flipped-voltage follower (FVF), can respond fast to the load step and input supply ripple. A replica loop is used to define the steady-state output current of AP, allowing a sufficient dynamic swing against the supply ripple. To lower the load current range with no LCO, the AP section will output all the current at very light load. An error amplifier (EA) with moderate gain is added to improve the light-load output accuracy. This EA also improves the PSR by approximately 6 dB. Fabricated in a 65-nm CMOS process, a 65-mV undershoot is measured with a 0–10-mA load current step under 0.6-V supply voltage and 50-mV dropout. Due to the fast AP, a 5-MHz operation clock is applied to the digital section, reducing the overall quiescent current to 29 $\mu \text{A}$ . A 0.37-ps figure of merit (FoM) is then achieved. A −22-dB PSR at 1 MHz is measured at 0.6-V supply, 100-mV dropout, and 10-mA load current.

From information, to data, to knowledge – Digital Scholarship Centers: An emerging transdisciplinary digital knowledge and research methods integrator in academic and research libraries

In this essay, the authors will discuss the similarities and differences of knowledge management and librarianship. They will propose and articulate the emerging role of academic and research libraries as the integrators of digital knowledge and research methods among academic enterprises, a role which they believe will transform librarians to knowledge professionals. The authors will try to answer or stimulate further discussion of multi-dimensional and provocative questions such as: What are the critical differences between knowledge management and library and information science? Will emerging functions or services, such as digital scholarship centers and research data management practices, allow academic and research libraries to more fully perform the functions of knowledge management? Will libraries’ emerging role in the knowledge creation ecosystem help define their new value proposition, from a collection-centric to knowledge-centric service model? How should libraries position library-based digital scholarship centers to be digital integrators for enterprise-wide digital learning, research, and knowledge creation?

Design and implementation of second-order microwave integrator

ABSTRACTIn this paper, a new design methodology is developed for the implementation of a second-order microwave integrator on microstrip circuit. Firstly, an existing digital first-order integrator with best magnitude and phase performance is adopted as a prototype to give digital second-order integrator transfer function. Then, by using the autoregressive process and a least mean square based error function, coefficients of the formulated second-order digital integrator are transformed into the impedance values of transmission line elements. Different sets of impedance values are obtained through the optimization process, and design with a highly accurate frequency response having maximum relative error value not more than 7.2% over the angular frequency range 0.18pi to 0.94pi is selected for implementation purpose. RT/Duroid 5880 is used to fabricate the proposed second-order microwave integrator design. Measured results for transmission coefficient S21(f) are found to follow theoretical values over the frequency range of 1.8 GHz to 8.6 GHz.

Fast pulse sampling module for real-time neutron–gamma discrimination

An adaptable and compact fast pulse sampling module was developed for the neutron–gamma discrimination. The developed module is well suited for low-cost and low-power consumption applications. It is based on the Domino Ring Sampler 4 (DRS4) chip, which offers fast sampling speeds up to 5.12 giga samples per second (GSPS) to digitize pulses from front-end detectors. The high-resolution GSPS data is useful for obtaining precise real-time neutron–gamma discrimination results directly in this module. In this study, we have implemented real-time data analysis in a field programmable gate array. Real-time data analysis involves two aspects: digital waveform integral and digital pulse shape discrimination (PSD). It can significantly reduce the system dead time and data rate processed offline. Plastic scintillators (EJ-299-33), which have proven capable of PSD, were adopted as neutron detectors in the experiments. A photomultiplier tube (PMT) (model #XP2020) was coupled to one end of a detector to collect the output light from it. The pulse output from the anode of the PMT was directly passed onto the fast sampling module. The fast pulse sampling module was operated at 1 GSPS and 2 GSPS in these experiments, and the AmBe-241 source was used to examine the neutron–gamma discrimination quality. The PSD results with different sampling rates and energy thresholds were evaluated. The figure of merit (FOM) was used to describe the neutron–gamma discrimination quality. The best FOM value of 0.91 was obtained at 2 GSPS and 1 GSPS sampling rates with an energy threshold of 1.5 MeVee (electron equivalent).

A 72.4-dB SNDR 92-dB SFDR Blocker Tolerant CT $\Delta\Sigma$ Modulator With Inherent DWA

This brief presents the design and implementation of a new blocker tolerant wideband continuous-time delta-sigma modulator. Using a customized digital integrator with inherent data-weighted averaging at the back-end of the modulator, the power consumption of the quantizer is reduced while the speed of operation is increased. Additionally, by using a single amplifier biquad structure in the loop filter, the number of op-amps is reduced, thus reducing the analog power consumption. Also, the modulator robustness to the out-of-band blocker is improved by increasing the number of levels in the digital integrator and feedback DACs. The out-of-band blocker tolerance is improved by 3 dB compared to a conventional CIFF-B delta-sigma modulator with a minimal increase in the power consumption. The proposed architecture has been implemented in a 65-nm CMOS technology and operates at a 250 MHz sampling frequency. It achieves 73.5 dB SNR, 72.4 dB SNDR, and 92 dB SFDR over a 7-MHz bandwidth and a Walden figure-of-merit of 341 fJ/conversion.

Transforming characteristics of the Rogowski coil current transformer with a digital integrator for high‐frequency signals

The Rogowski coil current transformer is widely used in intelligent substations for its rapid response, wide bandwidth measurement, and non-magnetic saturation. In most cases, it works with a digital integrator to restore the differential signal output by the coil. However, its output waveform can be deformed when transforming high-frequency signals generated in the transient process of the power system. The working process of the Rogowski coil current transformer is presented, including Rogowski coil head transferring, analogue filter filtering, analogue-to-digital converter sampling, and digital integrator restoring. The reason for the waveform deformation when transforming high-frequency signals is investigated by theoretical derivation. In order to show the waveform deformation phenomenon, an experiment is devised and the results output by the Rogowski coil transformer and low power current transformer are compared and analysed. Several measures to improve the output waveform deformation are proposed, such as increasing the sampling rate of the converter, decreasing the cut-off frequency of the filter, or replacing the digital integrator with the analogue integrator. The researches provide important guidelines for the application of the Rogowski coil current transformer with the digital integrator in the case of frequency aliasing.

A Hybrid PLL Using Low-Power GRO-TDC for Reduced In-Band Phase Noise

In this brief, we propose a hybrid phase locked loop (PLL) which employs a coarse resolution gated ring oscillator time-to-digital converter in the digital integral (I) path and a switched RC circuit in the analog proportional (P) path, which provide lower in-band noise than a bang-bang phase detector-based hybrid PLL (BB-HPLL). We also present noise analysis of the proposed PLL which shows that in-band noise can be further reduced by increasing the integral path gain, which is contrary to conventional design of BB-HPLLs where I path gain is minimized. A prototype chip fabricated in the 65-nm CMOS achieves 13-dB improvement of in-band phase noise compared to a conventional hybrid PLL and 2.08 psrms jitter at 4.8 GHz, while consuming 2.22 mW from a 1.0-V supply.

A Fractional-Order Noise-Shaping Integrator for Sigma-Delta Modulator

A novel fractional-order Sigma-Delta modulator, which can improve the signal to noise ratio (SNR) and is of robust stability of a high order Sigma-Delta modulator, is presented in the paper. Traditional Sigma-Delta modulator mainly focused on forming an integer high order integrator to improve the SNR, whereas the paper presents a fractional-order integrator instead to obtain higher SNR and better stability. Specifically, a 4th order digital integrator and a fractional-order PIλ controller are inserted between the AFE and the quantizer. The 4th order digital integrator increases overall loop order to produce much higher SNR for Sigma-Delta modulator and the fractional-order PIλ controller allows fine tuning accuracy in seeking the coefficients for Sigma-Delta modulator and provides stability in the placement of poles and zeros for compensating the phase delays caused by system nonlinearity. The parameters of PIλ controller are optimized by using swarm intelligent optimization algorithm. The stability of the proposed fractional-order Sigma-Delta modulator is analyzed and the robustness of the proposed fractional-order Sigma-Delta modulator is demonstrated. Further simulation from the fractional-order Sigma-Delta modulator, results of SNR>145dB and the noise floor under -190dB are obtained in frequency range of [5-150Hz].

Локальная интерполяция и аппроксимация в задачах эвристического синтеза цифровых фильтров

The article has an overview character with elements of generalization, but at the same time it includes information brought to the level of immediate practical implementation. Approaches to heuristic and functional synthesis of digital filters based on local nterpolation and approximation are considered. Digital differentiators based on local polynomial interpolation, digital integrators based on local polynomial and spline interpolation and digital filters with a U-shaped amplitude-frequency characteristic based on polynomial OLS approximation are obtained. The obtained results can be used in practice according to their functional purpose, taking into account the recommendations mentioned. The idea of numerical differentiation based on interpolation is not new, but the deep connection between this approach and digital filtering is not often reflected in literature due to the fact that this concept is limited to numerical differentiation based on finite differences. The gap is filled in this work. Numerical integration is usually considered on the basis of stepwise or piecewise linear or piecewise parabolic interpolation (method of rectangles, trapezoids, Simpson). However, regardless of the choice of the interpolation method, the digital integrator has a certain generalized structure, and approaches to numerical integration can be based on more effective methods of interpolation, which is shown in the article. The OLS filters (Savitzky-Golay) are described in the literature. However, the steps for their practical implementation are clearly insufficient. Traditionally the general description of filters does not develop further 4th degree of the approximating polynomial and is often limited to the moving average filters. The frequency properties of the filters are also not fully described. In this work the description of the OLS filters obtained at the degree of the approximating polynomial 0-8 was given, their frequency properties were studied, and sufficient information was given to obtain digital filters based on them with a U-shaped amplitude-frequency characteristic without pulsations in the passband. Thus, the field of filters application is extended beyond the OLS smoothing.

DIGITAL PHASE FREQUENCY METER DISTANCE

Problems. Optical distance meters allow measurements of distances to various probing objects. One of the problems is to provide high-resolution, precision and resolution of light-range finders. Therefore, research and improvement of these parameters is relevant. The main methods of constructing equipment for measuring distances are pulsed and phase methods. The purpose of the research. In the article the variant of construction of the structural scheme of the phase-pulse distance meter is used with the use of a highly stable quartz oscillator. Implementation method. The use of a single source of quartz frequency for the formation of a low frequency modulation of the light flux, the reference frequency of the measuring channel and two pulses of quantization frequencies, the selected phase intervals, increases the stability of the parameters of both the emitted light flux and the response signals when converted. The use of a digital cache integrator allows, for example, 10 or 100 times to reduce the effect of these components by determining the average value of bundles of pulses from a selected integer number. Conclusions. The proposed algorithm for choosing the ratio of frequency modulation and quantization frequencies can improve the accuracy and resolution of distance measurement, due to the possibility of changing the quantization frequency and the weight of the electronic scale. The introduction of digital signal processing and the integration of the dedicated phase-frequency range increases the resistance of the meter to the noise effects of the external environment and the configuration of the object of study on the parameters of the light flux. Further promising research and development of the proposed technical solution may be the development of a scheme for compensating the hardware noise of the measuring channel, using an additional switching-modulation conversion, which will increase the sensitivity of the light-meter and increase the measurement range of the proposed device.

Research on Electronic Voltage Transformer for Big Data Background

A new type of electronic voltage transformer is proposed in this study for big data background. By using the conventional inverted SF_6 transformer insulation structure, a coaxial capacitor sensor was constructed by designing a middle coaxial electrode between the high-voltage electrode and the ground electrode. The measurement of the voltage signal could be obtained by detecting the capacitance current i of the SF_6 coaxial capacitor. To improve the accuracy of the integrator, a high-precision digital integrator based on the Romberg algorithm is proposed in this study. This can not only guarantee the accuracy of computation, but also reduce the consumption time; in addition, the sampling point can be reused. By adopting the double shielding effect of the high-voltage shell and the grounding metal shield, the ability and stability of the coaxial capacitor divide could be effectively improved to resist the interference of stray electric fields. The factors that affect the coaxial capacitor were studied, such as position, temperature, and pressure, which will influence the value of the coaxial capacitor. Tests were carried out to verify the performance. The results showed that the voltage transformer based on the SF_6 coaxial capacitor satisfies the requirements of the 0.2 accuracy class. This study can promote the use of new high-performance products for data transmission in the era of big data and specific test analyses.