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This paper presents three pieces that use objects, or object types, to reveal the material, personal, institutional and commercial networks that surrounded the introduction and successful use of instruments, systems and techniques. The objects explored are: the Hourly Signal Relay, used within the time signal system of the Royal Observatory, Greenwich, from the mid-nineteenth century; photographic glass plates from the British 1874 transit of Venus expeditions; and an electronic imaging tube, Lallemand's camera, developed in Paris and used at the Lick Observatory in California in the 1960s. Each story uses examples of failure as a means of highlighting a lack of robustness in or effort required to maintain these networks. Once created, however, such networks could, as the second two stories note, go on to develop and support alternative approaches, helping to create success from apparent failure. Nevertheless, complexity, failure and fragility have also led to the underrepresentation or obscurity of these objects in museum collections, until given focused attention in these studies. The paper forms part of a collection of articles: Revealing observatory networks through object stories. The other papers in the collection are 'Object itineraries', and 'Observatory audiences' and the genesis of the collection is discussed in the 'Introduction'. [ABSTRACT FROM AUTHOR]

Introduces the themes of the research papers featured in the October 2005 Special Issue of the "IEEE Journal of Solid-State Circuits." Description of a high-efficiency C-band amplifier for satellite communication systems; Presentation of experimental circuits in the InP DHBT technology; Development of a 220-GHz low-noise amplifier for use in high-resolution active and passive millimeter-wave imaging systems.

Periodic structures have gained attention in the research community since they show attenuation zones in their frequency response, called bandgaps. In this paper, the interactions of two mechanisms of bandgap formation in mono-coupled periodic structures are examined, i.e., Bragg scattering and local resonators. With reference to longitudinal elastic waves, an analytical study is carried out to describe in detail the formation of bandgaps. Local resonators are implemented via piezoelectric inserts shunted with a resonating electrical circuit for which a non-traditional model is needed since the study concerns higher frequencies with respect to those of the subwavelength regime. Design maps and tuning formulas are developed not only for the case of infinite structures, but also for the finite case, highlighting the role of the number of unit cells and that of resonances in the attenuation zones. Among the possible tuning strategies of local resonators, it is shown that the mutual influence between elastic and electric parameters is able to produce a wider attenuation zone, bridging Bragg scattering bandgaps thanks to the effect of local resonators. The analytical findings of this paper are validated with numerical results in an example application. [ABSTRACT FROM AUTHOR]

A transient and static hybrid-triggered active clamp is proposed in this paper. By skillfully incorporating different detection mechanisms, the proposed clamp achieves enhanced static electrical overstress protection capability over the transient one. Furthermore, the proposed clamp achieves improved electrostatic discharge reaction speed in both human body model and charged device model events over the static one. Moreover, the superior transient-noise immunity of the proposed clamp over traditional transient ones is essentially revealed in this paper. The proposed clamp is successfully verified in a 65-nm bulk CMOS process. In addition, the design flexibility of the proposed clamp for other processes is also deeply discussed in this paper. [ABSTRACT FROM PUBLISHER]

Provides instructions and guidelines to prospective authors who wish to submit manuscripts. [ABSTRACT FROM AUTHOR]

This paper presents the development and design of a fully-balanced current-tunable first-order low-pass filter with Caprio technique, which could include the design and implementation of a first-order low-pass filter circuits. The filter consists of six bipolar junction transistor (BJT) and a single capacitor. The filter construction uses a bipolar junction transistor (BJT) as the main device and a single capacitor. A fully-balanced current-tunable first-order low-pass filter with Caprio technique developed. The architecture of the circuit is quite simple and proportional, symmetrical with signs of difference. Circuits developed into integrated circuits act like basic circuits for frequency filter circuits, current modes with Caprio techniques, obtained by improving the first-order low-pass filter for signal differences with incoming impedances. Adjusting the parameters of the circuit with the caprio technique achieves the optimal parameter value for correcting the total harmonic distortion value. The results of testing the operation of the circuit, a fully-balanced current-tunable first-order low-pass filter with Caprio technique developed and designed using the PSpice program. The simulation results showed good results in line with predicted theoretical analysis. The sensitivity of the device to the center frequency (ω0) response is low and independent of variables, the angular frequency is linear with wide current adjustment throughout the sweeping range of a wide frequency range, with a wide range of over tree orders of magnitude. Therefore, fully-balanced current-tunable first-order low-pass filter developed is very suitable to apply various applications regarding low frequency signal filtration, for example in biomedical systems, for example. [ABSTRACT FROM AUTHOR]

Many applications require a low-cost and large-scale mode of flexible electronics with reasonably high photoresponse that can be detected without high precision measurement systems. We demonstrate a very easy to fabricate ZnO UV sensor, made on common pencil drawn circuit over a paper. ZnO nanocrystals were extracted in a high throughput via a simple and green route. This sensor is well capable of detecting UV light and demonstrates features comparable to those of made with complex and expensive techniques. [ABSTRACT FROM AUTHOR]

Comments on a paper which suggests a ring hybrid adopting a Marchand balun. Use of the main concept that the ring hybrid consists of an in-phase divider and a balun; Comparison between measured and theoretical results of a Marchand balun without an in-phase power divider.

In this paper, the sequential conformable Langevin-type differential equation is studied. A representation of a solution consisting of the newly defined conformable bivariate Mittag-Leffler function to its nonhomogeneous and linear version is obtained via the conformable Laplace transforms' technique. Also, existence and uniqueness of a global solution to its nonlinear version are obtained. The existence and uniqueness of solutions are shown with respect to the weighted norm defined in compliance with (conformable) exponential function. The concept of the Ulam–Hyers stability of solutions is debated based on the fixed-point approach. The LRC electrical circuits are presented as an application to the described system. Simulated and numerical instances are offered to instantiate our abstract findings. [ABSTRACT FROM AUTHOR]

In this paper, we focus on the development of a machine for manufacturing needle probes used in the electrical testing of printed circuit board (PCB) in-circuit-test fixtures. Currently, the manufacturing process for needle probes involves manual tasks such as wire threading, soldering, heat shrink tubing application, heat shrink tubing heating, and placing cylindrical terminals into a needle disc. Owing to the time-consuming nature of this production process, automation is proposed for improvement. The system development involves programmable logic controller (PLC) control and pneumatic cylinder mechanisms to replicate the manual wire threading process. Pneumatic grippers are used to position cylindrical terminals and heat shrink tubing. Two stepper motors drive plastic rollers for copper wire extension by a rolling process along V-shaped groove straightening guides, reaching the wire insertion holes on the PCB. A YZ-axis servo stage with clamping fixtures secures the PCB and moves it to the wire insertion holes. Once the copper wire extends through the cylindrical terminal, the threading action for that PCB hole is completed. Subsequently, laser welding joins the cylindrical terminal with the copper wire, and a hot air blower fuses the heat shrink tubing with the cylindrical terminal. Pneumatic grippers grasp the threaded cylindrical terminals. Simultaneously, an XY-axis servo stage with clamping fixtures places the disc into the clamping fixture, moves it beneath the pneumatic grippers, and inserts the cylindrical terminals into the disc. After completion, a few centimeters of copper wire in front of the rollers are cut, marking the completion of the needle placement for that hole on the disc. The combination of PCB hole wire threading and disc hole needle placement constitutes one cycle of the wire threading fixture. The machine repeats this automated sequence until the entire needle probe fixture is produced. [ABSTRACT FROM AUTHOR]

Several existing research studies on the modeling of photovoltaic (PV) systems feeding a resistive load through a DC-DC converter have proven that the use of the small-signal approach using analytical or graphical methods for the design of a linear model is failing. This is due to the fact that the simplified linear model, usually presented by a transfer function, is unable to reveal all the existing information about the actual solar system behavior when subjected to the Standard Test Conditions (STC). Since it does not take into account: (i) the nonlinearity of the current–voltage (I-V) characteristic of the solar panel, (ii) the presence of elementary components in both the solar panel and the DC-DC converter, which are often unmodeled and cannot be easily considered in the modeling, (iii) the existence of extra components in the DC-DC converter and more dynamics that must be neglected at high frequencies, for example those describing the thermal energies dissipated in the IGBT part of the DC-DC boost converter, the presence of cross-coupling between some electrical quantities occurring either in the DC-DC boost converter or in the solar panel, etc. For these reasons, this paper proposes a new design of a small-signal linear model to accurately describe the actual solar system behavior operating at STC. This is achieved by considering its internal functioning as a black box where only its input–output measurements are available in the form of frequency response data (FRD), generated by running a free stand-alone Plecs® software package. As this software has the ability to perfectly model the behavior of boost DC-DC converters, previously connected by variable resistive loads, it is possible thanks to the existence of equivalent electrical circuits, available in its own library. Unfortunately, this library lacks an equivalent circuit for the KC200GT photovoltaic panel where its design is needed through evaluating its current–voltage characteristics. The resulting global model is then simulated in the modified Plecs® software, providing the desired FRDs. These are used to estimate the parameters of the proposed linear model, which then used for tuning the PID controller. Here, this controller is combined with the standard Maximum Power Point Tracking (MPPT) strategy based on the direct implementation of the Incremental Conductance (INC) algorithm, highlighting therefore the proposed improved INC-MPPT strategy. It perfectly overcomes the ripple problems encountered in some electrical components of the solar system when controlled by the standard INC-MPPT strategy. As the proposed improvements depend on the model accuracy, the main contribution of this paper lies therefore on the necessary steps to design this proposed small-signal model. [ABSTRACT FROM AUTHOR]

Many complex engineering systems can be represented in a topological form, such as graphs. This paper utilizes a machine learning technique called Geometric Deep Learning (GDL) to aid designers with challenging, graph-centric design problems. The strategy presented here is to take the graph data and apply GDL to seek the best realizable performing solution effectively and efficiently with lower computational costs. This case study used here is the synthesis of analog electrical circuits that attempt to match a specific frequency response within a particular frequency range. Previous studies utilized an enumeration technique to generate 43,249 unique undirected graphs presenting valid potential circuits. Unfortunately, determining the sizing and performance of many circuits can be too expensive. To reduce computational costs with a quantified trade-off in accuracy, the fraction of the circuit graphs and their performance are used as input data to a classification-focused GDL model. Then, the GDL model can be used to predict the remainder cheaply, thus, aiding decision-makers in the search for the best graph solutions. The results discussed in this paper show that additional graph-based features are useful, favorable total set classification accuracy of 80% in using only 10% of the graphs, and iteratively built GDL models can further subdivide the graphs into targeted groups with medians significantly closer to the best and containing 88.2 of the top 100 best-performing graphs on average using 25% of the graphs. [ABSTRACT FROM AUTHOR]

This paper concerns the effects of electrodynamic forces that act on current paths that are part of high-grade industrial distribution switchgear. This work is composed of experimental and simulation sections. In the experimental section, the short-circuit tests are presented and the occurrence of electrodynamic forces are shown in a visible way. The formation of electrodynamic forces in the current circuits of electrical energy distribution systems is related to the flow of high currents, but mostly it is related to short-circuit currents. In order to highlight these phenomena, the detailed specification of the parameters during tests is displayed. In the simulation section, the physical phenomenon of electrodynamic forces is being captured by employing a detailed real-scale model of switchgear and current paths. Therefore, the authors proposed employment of the FEM (finite element method) in order to obtain values of electrodynamic forces acting on the current paths by executing the detailed 3D coupled simulation. The analysis of the results and aftermath effects of their interactions provided interesting conclusions that concerned the operation of such power distribution layouts in critical short-circuit conditions. [ABSTRACT FROM AUTHOR]

Engaging and understanding student-thinking in electrical circuit design can be challenging. While the analysis of circuits is an important component of an Analog Electronics course, one of the primary areas of difficulty faced by students is that they do not have a clear understanding of the current flow. Attempts at mediating this gap are usually limited to the use of metaphors and (too) much is left to the learners' imagination. This paper reports an intervention co-designed with a lecturer with regard to an undergraduate module on Analog Electronics. The intervention was an open-source immersive virtual environment designed to afford representations of learner intuitions in electrical circuit design with a view to helping their tutor have a better understanding of the roots of their misconceptions. The paper highlights some of the benefits and challenges of using immersive environments and the design and development process, as well as the collaborative learning that resulted. [ABSTRACT FROM AUTHOR]

This paper proposed modeling, designing and battery management system for a three-wheeled electric vehicle for the Indian road under different conditions. The system consists of a lithium nickel manganese cobalt oxide cell-based lithium-ion battery with a managing system known as battery management system (BMS) described here. The process for modeling the vehicle, choosing the motor, developing the controller with a programmable circuit and developing the DC–DC buck converter, and battery pack of the lithium-ion cell with an effective BMS is discussed. According to the study, a prototype programmable controller circuit board, including the PWM-controlled driver circuit, is built for the proper flow of electricity on urban roads in India and has been tested successfully on road. This developed electric prototype travels the range of 100 km with an average speed of 32 km/h, while the maximum current drawn from the battery is 30_amp. The efficiency increased by 2% compared to the market-available PWM square wave controller. MATLAB simulation is done to compare the effectiveness of the modeled system with the suggested prototype control system. To verify the system, a small-scale prototype is developed. [ABSTRACT FROM AUTHOR]

To tackle the complex wireless power supply requirements in the Automated Material Handling System (AMHS) of semiconductor wafer factories, this paper presents a design method for a magnetic coupling mechanism based on a Multi-Segment Wireless Power Transfer (MSWPT) system for dynamic wireless power supply in segmented track configurations. Firstly, the track is approached using Inductive Power Transfer (IPT) technology combined with an LCC-S resonant structure transmitter (Tx). Following this, the feasibility of the H-type pickup is assessed through magnetic and electrical circuit analyses, which leads to the preliminary determination of the pickup dimensions by means of finite element magnetic and thermal simulations. Furthermore, an analysis of the mutual inductance drop is conducted under various track structure parameters during track crossing and curve negotiation operation conditions. Secondly, a dual-coil winding method is proposed to reduce the insulation stress on the PCB board. Additionally, a method for calculating the wire length and a design process for the overall parameters of the pickup are derived. Finally, two Txs and a 1.5 kW power receiver (Rx) were designed to verify the mutual inductance fall under the aforementioned conditions. During low-speed full-load operations, a constant-voltage output was achieved through the proposed dual-loop PI control strategy, thereby meeting the requirements for a constant-voltage output in industrial applications. [ABSTRACT FROM AUTHOR]

This article discusses the behavior of lubricated bearings in electric circuits, which has become increasingly important due to the growing electrification of individual mobility and renewable energy technologies. The research work in this field is predominantly published in German, so this special issue aims to provide a comprehensive overview of the topic. The article explores various models and methods for analyzing the electrical impedance behavior of rolling and plain bearings, as well as the potential for using bearings as integrated sensors in industrial processes. The challenges and potential applications of using electrical properties of bearings for damage detection and predictive maintenance are also discussed. The special issue includes several research papers that cover different aspects of this topic, including electrical bearing currents, lubricant film conditions, surface topology, strain measurement, and the factors influencing bearing currents. The authors express their gratitude to the contributors and reviewers for their valuable contributions. [Extracted from the article]

Metamaterial technology indeed holds great promise for enhancing wireless communication, especially in the development of advanced filters and devices. The use of metamaterials for filter design is an exciting and promising area of research, driven by their exceptional properties and potential for revolutionizing various technological applications. In fact, Metamaterials can be engineered to exhibit unique electromagnetic properties, allowing for precise control of the filtering characteristics. This enables designers to create filters with sharp passbands and stopbands, as well as customizable cutoff frequencies. Besides, Metamaterials can be used to miniaturize filters, making them suitable for compact and portable devices. This is especially valuable for applications with size constraints, such as mobile phones and wearable technology. Moreover, Metamaterials provide the flexibility to design filters with adjustable bandwidth. In this paper, a triple band pass printed filter using split-ring resonators is designed and simulated. The proposed filter is composed of two split-ring arrays loaded on the transmission line. It is printed on a Rogers RT/duroid 6010/6010LM (tm) substrate. The proposed BPF has a small size (14 × 16 mm²) and high selectivity. The simulation result exhibit three passbands centered at 3.15 GHz, 6.27 GHz and 9.31 GHz, respectively with required return loss and insertion loss characteristics. The simulation studies are carried out with HFSS software and its electrical equivalent circuit model (ECM) is designed using ADS tool. The results obtained using HFSS is in well agreement with ECM results. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a pioneering numerical technique that combines generalized Laguerre polynomials with an operational matrix of fractional integration to address fractional models in electrical circuits. Specifically focusing on Resistor-Inductor (RL), Resistor-Capacitor (RC), Resonant (Inductor-Capacitor) (LC), and Resistor-Inductor-Capacitor (RLC) circuits within the framework of the Caputo derivative, our approach aims to enhance the accuracy of numerical solutions. We meticulously construct an operational matrix of fractional integration tailored to the generalized Laguerre basis vector, facilitating a transformation of the original fractional differential equations into a system of linear algebraic equations. By solving this system, we obtain a highly accurate approximate solution for the electrical circuit model under consideration. To validate the precision of our proposed method, we conduct a thorough comparative analysis, benchmarking our results against alternative numerical techniques reported in the literature and exact solutions where available. The numerical examples presented in our study substantiate the superior accuracy and reliability of our generalized Laguerre-enhanced operational matrix collocation method in effectively solving fractional electrical circuit models. [ABSTRACT FROM AUTHOR]

This paper presents a low-voltage CMOS four-stage amplifier operating in the subthreshold region. The first design technique includes the cross-feedforward positive feedback frequency compensation (CFPFC) for obtaining better bandwidth efficiency in a low-voltage multi-stage amplifier. The second design technique incorporates both the bulk-drain-driven input stage topology in conjunction with a low-voltage attenuator to permit operation at a low voltage, and improves the input common-mode range (ICMR). The proposed circuit is implemented using TSMC-40 nm process technology. It consumes 0.866 μW at a supply voltage of 0.5 V. With a capacitive load of 50 pF, this four-stage amplifier can achieve 84.59 dB in gain, 161.00 kHz in unity-gain bandwidth, 96 deg in phase margin, and 5.7 dB in gain margin whilst offering an input-referred noise of 213.63 n V / H z @1 kHz, small-signal power-bandwidth FoMss of 9.31 (MHz∙pF/μW), and noise-power per bandwidth-based FoMnpb of 1.15 × 10−6 (( µ V / H z )·µW/Hz). Compared to the conventional bulk-driven input stage design technique, it offers improved multi-parameter performance metrics in terms of noise, power, and bandwidth at a compromising tradeoff on ICMR with respect to bulk-driven amplifier design. Compared with conventional gate-source input stage design, it offers improved ICMR. The amplifier is useful for low-voltage analog signal-processing applications. [ABSTRACT FROM AUTHOR]

The soft set theory proposed by D. Molodtsov in 1999 is a general mathematical method for dealing with uncertain data. Now many researchers are applying soft set theory in decision making problems. Graph theory is the mathematical study of objects and their pairwise relationships, known as vertices and edges, respectively. The concept of soft graphs is used to provide a parameterized point of view for graphs. Directed graphs can be used to analyze and resolve problems with electrical circuits, project timelines, shortest routes, social links and many other issues. We introduced the notion of the soft directed graph by applying the concepts of soft set in a directed graph. In this paper, we introduce the concept of soft subdigraph and some soft directed graph operations like AND operation, OR operation, soft union, extended union, extended intersection, restricted union and restricted intersection and investigate some of their properties. [ABSTRACT FROM AUTHOR]

Peer learning is one method to encourage meaningful learning in electrical engineering courses. It involves the sharing of ideas, knowledge, and experiences and emphasizes interpersonal learning. However, there are different viewpoints in relation to the best way to implement and assess peer learning in a lab environment, and contemporary literature on online laboratories (OL) rarely explores peer learning opportunities. In this paper, we aim to investigate the benefits of students' peer learning activity in an online electronics lab course. The key challenge was whether the OL could ensure smooth communication and collaboration between the students. In our case, we applied Zoom online conferencing software as a communication tool and LabsLand as an interactive OL tool. Specifically, we used a remote lab application for electrical circuit building, which makes physically existing lab infrastructure remotely usable through an online user interface. Methods we used to assess our learning outcomes included online surveys, online lab usage, and lab report scores. The survey results showed there are positive opinions about component skill development from group lab activities. In an online lab, the tasks were divided based on team members' strengths. In terms of peer learning, some students felt there was an improvement in partners' skills in terms of the circuit assembly. The OL usage showed a high level of engagement in group activity. Students willingly spent more time on lab experiments beyond regular lab hours. The scores of lab reports showed this new way of peer learning could achieve learning outcomes comparable to conventional, physical labs using peer learning. Accordingly, we concluded that the OL was an alternative and effective way to encourage peer learning. [ABSTRACT FROM AUTHOR]

The article shows the possibility of reducing the temperature coefficient for the bandgap voltage reference (BVR) built on bipolar transistors. To do this, as the first step, it is proposed to divide the temperature range of BVR operation into two intervals. Since the most probable working interval corresponds to the range of positive temperatures, such division makes it possible to halve the temperature coefficient for the most probable working area on condition of an appropriate BVR adjustment. The introduction of weights for BVR optimization involves giving preference to the working interval of positive temperatures. It provides a direction of search for the optimal solution when formalizing the optimization process. The second step involves the proposal of a functional block diagram with compensators of the decline of temperature characteristic. The paper also proposes electric circuits of a typical compensator and the circuits for connecting one and two compensators to uncompensated BVR. This also determines the rule of introducing further compensators, if expedient. The parametric optimization of the proposed BVR circuits and the experimental study of BVR circuit with one compensation link have been performed. The above optimization resulted in a reduced value of temperature coefficient at the level of 2.88 ppm/°C for the circuit with one compensator and 1.0 ppm/°C for the case of connecting two compensators to BVR circuit that surpasses the latest published achievements. When expanding the temperature range into the area of low temperatures and using additional compensators in accordance with the specified schematic block diagram, we could expect the reduction of the temperature coefficient to 0.25–0.5 ppm/°C. [ABSTRACT FROM AUTHOR]

Computer based learning and laboratory-based learning are widely used nowadays mainly for teaching and learning of both teacher and students especially in teaching electrical circuits. This paper aims to review computer-based learning and laboratory-based learning, specifically other forms of CBL and LBL and how these methods are integrated in teaching and learning electrical circuits, and its advantages and disadvantages. In conducting this literature review, the researchers adapted the PRISMA method in which various journal articles are screened through different stages. Criterion was imposed to guide the researchers in the inclusion and exclusion process. It was found out that there are other forms of computer-based learning (CBL) such as the Java-based virtual laboratory and Grid computing laboratory. Also, integrating computer-based learning and laboratory-based learning would build a workable environment that helped in motivating students in exploring electrical circuits. There are various advantages of computerbased learning such as time saving and easy access to laboratory manuals. On the other hand, advantages of laboratory-based learning include the positive impact of interaction, group discussion, and collaboration that was delimited by the computer-based learning. [ABSTRACT FROM AUTHOR]

The paper deals with an automatic curtain moving system. Here shown the process of design and build prototype. Solution of problem included design of mechanical construction, electric circuit and program of control. Nowadays is so popular to build houses by sandwich panel. This building method allows quick and modular process of building of halls. In this paper found a possible way for also quick and modular automatic curtain moving system. Chapters deal with initial known and added parameters and the problem. Furthermore, paper says about curtain cornice solutions, sliding ways, design of sheet metal components, DC motor choice, microcontroller and communication preparing. At the end found the conclusion of first prototype. [ABSTRACT FROM AUTHOR]

The paper investigates the controllability of fractional descriptor linear systems with constant delays in control. The Caputo fractional derivative is considered. Using the Drazin inverse and the Laplace transform, a formula for solving of the matrix state equation is obtained. New criteria of relative controllability for Caputo’s fractional descriptor systems are formulated and proved. Both constrained and unconstrained controls are considered. To emphasize the importance of the theoretical studies, an application to electrical circuits is presented as a practical example. [ABSTRACT FROM AUTHOR]

In the present paper the application of the Laplace transform and its inverse transform for solving ordinary differential equations with constant coefficients and initial condition is considered. The solution of an ordinary differential equation that describes a serial RLC circuit is provided. Some results of the simulations are also given. [ABSTRACT FROM AUTHOR]

The permutation largest slope entropy (PLSE) algorithm has been shown to be effective to distinguish between regular and non-regular dynamics from time series analysis. However, as it is the case for many non-linear time series analysis algorithms, such a characterization is locally made and does not allow one to capture some micro-phenomena, such as intermittency, that may occur in the system behavior. This paper presents a PIC micro-controller based implementation of the PLSE for a real-time monitoring of system dynamics. The PLSE algorithm is optimized to fit the program and data memory of low-end processors using the XC8 compiler and the MPLAB X IDE. The resulting algorithm is implemented on the PIC16F18446 and deployed on the Explorer 8 development board. The effectiveness of the developed tool is validated by considering an electrical circuit of the Duffing oscillator that can generate both periodic and chaotic dynamics. By comparing the PLSE values with the phase portraits and previous results on the Duffing oscillator circuit, the developed tool efficiently allows one to monitor the behavior of dynamical systems. [ABSTRACT FROM AUTHOR]

This paper presents a new configuration to tackle a twofold problem affecting a crankshaft: the torsional vibrations and the oscillation of the speed at the back end of the shaft due to the torque ripples created by the cylinders. These two phenomena already have industrial solutions, but the requirement levels increase and impose constant improvements. Moreover, the common vibration dampers rely on energy dissipation as heat, which in a context of waste reduction could be avoided. This concept relies on the association of an optimal passive mechanical damper, an electric circuit and electromechanical converters, without any external power supply, in order to ensure a safe operation. From a more fundamental point of view, these elements link a time-periodic correction and a nonstationary cyclic excitation. The core idea of the concept is to enable a redistribution of the energy within this coupled electromechanical circuit, where each element can behave as a power consumer or supplier, so that the oscillations of the mechanical elements can be decreased. In this paper, the authors describe and model this new concept in order to investigate the resulting dynamic behavior and the key design parameters that affect the damping performance. [ABSTRACT FROM AUTHOR]

Magnetometers are important sensors with applications in the attitude determination and control systems of satellites. CubeSats have certain limitations related to power, mass, and volume. Due to this, CubeSat magnetometers are not separated from other electrical circuits inside the satellite. Thus, it is important to calibrate the magnetometer, simulating operating conditions while the satellite is running before the launch. However, due to the limited facilities, not every CubeSat is able to calibrate its magnetometers properly on the ground. This study focuses on the calibration of on-orbit magnetometer data observed by BIRDS-3 CubeSats with a genetic algorithm. High oscillations in the total magnetic field were found in the on-orbit magnetic field data measured by magnetometers inside BIRDS-3 CubeSats. Nine unknowns, scaling factors, non-orthogonal angles, and offsets are identified with the genetic algorithm. This paper discusses the factors that affect the high oscillations in the measured total magnetic field data. For the calibration, we used magnetic field data similar to those of a model magnetic field, as the deviation is smaller. This paper presents the accuracy of determining unknowns using the genetic algorithm, as well as the interchangeability of the answers with additional orbit data from the same satellite. This method can be used in the future to calibrate magnetometers inside CubeSats before or after launch. [ABSTRACT FROM AUTHOR]

Designing electrical circuits and devices is usually based on expertise in electronics and the thorough use of numerical software tools. This procedure can be time-consuming, and the designer has only one solution. This paper introduces a new approach focused on new concept design and optimization of specific circuits using symbolic expressions. The primary amplifier circuit, realized by a deep learning module, changes the value to reduce power dissipation. The control signal of the deep learning module is output from an amplifier that depends on the statistics of the input signal value. [ABSTRACT FROM AUTHOR]

With the increasing ubiquity of computing, more engineering programs now require their students to take one or more computing courses. At institutions where significant numbers of engineering students take computer courses, computing instructors and educators often assume roles that have them teaching their computing courses for non-majors as service courses, dealing with students with diverse backgrounds and varied motivations. Although teaching computing courses to non-majors is not new, the increasing importance of computing in future undergraduate engineering curricula poses new challenges. In this Special Issue, four of the papers offer insight into, and give evidence of, teaching computing to engineering students; the fifth paper investigates computational modeling abilities in conceptual understanding of electric circuits. [ABSTRACT FROM AUTHOR]

This paper proposed a method of synthesizing absorptive common-mode filters (A-CMFs) analytically with high absorption efficiency and two designable absorption bands. The proposed method is carried out by a novel circuit architecture and its analysis procedure. In differential mode, the integrity of the differential signals is maintained, and in common mode (CM), two absorption frequency bands can be obtained theoretically. These bands are designable with the analytical equations derived in this paper, so a dual-band or broadband A-CMF design can be easily synthesized by our proposed method. The authors also show that this method can make any one of R-CMFs “upgrade” to an A-CMF by simply adding an additional circuit, and this might be a revolutionary progress for the currently used CM-suppression techniques. To make the proposed concept more understandable, an example is used to demonstrate how the synthesizing methodology works, where a broadband A-CMF with its absorption bands located at 2.4 and 3.6 GHz is designed and implemented. Furthermore, a test sample of this A-CMF is fabricated on a four-layer printed circuit board. It is measured on a probing station, and the measured results are very similar to the simulated results. Finally, a comparison table of all the related works is given, showing that this proposed method really makes a significant improvement for A-CMF techniques. It is worth noting that this circuit design can provide a broadest 95%-absorption band to our best knowledge. [ABSTRACT FROM AUTHOR]

In this paper, the analysis of the accuracy of the electromagnetic time reversal method for unmatched media is carried out when the terminal impedances of the transmission line and/or of the defects along it are frequency dependent. Some numerical examples involving a medium-voltage power line and a high-speed interconnect are considered and the results discussed. [ABSTRACT FROM AUTHOR]

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This paper proposes a new and general method to optimize a working frequency and a load resistance in order to realize highly efficient wireless power transfer. It should be noticed that neither resonant frequency nor matched impedance maximizes efficiency of wireless power transfer circuit, in general. This paper establishes a mathematical model of a commonly used wireless power transfer circuit, and derives a mathematical expression of circuit efficiency which involves a working frequency, a load resistance and the other parameters as symbols. This enables us to find the optimal working frequency and load resistance. The result of this paper is compared with results by a method based on resonance and impedance matching, and then clarified by a numerical example. [ABSTRACT FROM AUTHOR]

String diagrams are a powerful and intuitive graphical syntax, originating in theoretical physics and later formalised in the context of symmetric monoidal categories. In recent years, they have found application in the modelling of various computational structures, in fields as diverse as Computer Science, Physics, Control Theory, Linguistics, and Biology. In several of these proposals, transformations of systems are modelled as rewrite rules of diagrams. These developments require a mathematical foundation for string diagram rewriting: whereas rewrite theory for terms is well-understood, the two-dimensional nature of string diagrams poses quite a few additional challenges. This work systematises and expands a series of recent conference papers, laying down such a foundation. As a first step, we focus on the case of rewrite systems for string diagrammatic theories that feature a Frobenius algebra. This common structure provides a more permissive notion of composition than the usual one available in monoidal categories, and has found many applications in areas such as concurrency, quantum theory, and electrical circuits. Notably, this structure provides an exact correspondence between the syntactic notion of string diagrams modulo Frobenius structure and the combinatorial structure of hypergraphs. Our work introduces a combinatorial interpretation of string diagram rewriting modulo Frobenius structures in terms of double-pushout hypergraph rewriting. We prove this interpretation to be sound and complete and we also show that the approach can be generalised to rewriting modulo multiple Frobenius structures. As a proof of concept, we show how to derive from these results a termination strategy for Interacting Bialgebras, an important rewrite theory in the study of quantum circuits and signal flow graphs. [ABSTRACT FROM AUTHOR]

This paper deals with generalised Caputo fractional proportional linear time-invariant systems in a finite-dimensional space. The Laplace transformation method ensures the analytical solution of the desired fractional linear time-invariant systems. The present article presents the necessary and sufficient conditions for controllability and observability of the generalised Caputo proportional fractional linear time-invariant systems. These two properties can play a more fundamental role in system analysis before controller and observer designs are engaged. Moreover, we have acquired the criterion for generalised Caputo proportional fractional linear time-invariant systems as Kalman rank conditions. Some numerical examples are presented to show the applicability of the paper to demonstrate our findings. Finally, we derive the necessary and sufficient controllability conditions for the generalised Caputo proportional fractional-order nonlinear Chua's electric circuit. [ABSTRACT FROM AUTHOR]

Smart Grid substations rely on conventional Supervisory Control and Data Acquisition (SCADA) systems for remote supervision and control. However, these systems are limited in the geographical area they cover. Recently, the Internet of Things (IoT) has paved the way for connecting a vast number of devices to the Internet, which would be effective and beneficial for power system automation and data acquisition. In this paper, an intelligent low-cost SCADA system based on IoT for transmission line fault diagnosis is proposed. In the first step of the proposed scheme, voltage and current signals at the relaying point are preprocessed and analyzed using Discrete Cosine Transform (DCT). Next, signal energy components are extracted and sent to a Boosted Decision Tree (BSDT), a reliable and fast ensemble classifier, to identify fault type and, accordingly, a specific ANN is activated to estimate fault location. The diagnosis data is sent to a microcontroller to be displayed, trip the load circuit, and allow communication with Cloud ThingSpeak platform via the ESP8266 wi-fi communication module which makes data available anywhere all over the world. The approach is applied on a real-world HV transmission line, located between Samalut and Cairo, Egypt, where more than 16000 faults cases are well tested. The results show the reliability, validity, and effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

First harmonic analysis (FHA) is arguably the most widely used analytical technique for wireless power transfer (WPT) circuits due to its simplicity. Although FHA can provide closed-form solutions, the existence of rectifier diode forward voltage drop and higher order harmonics, especially the second and third harmonics at variable duty cycle operation, can significantly deteriorate its accuracy. This paper presents an accurate and efficient method called enhanced multiple harmonic analysis (eMHA) for the optimal design and optimal control of WPT systems. The eMHA method considers the nature of nonlinear rectification networks under nonsinusoidal current and reexamines the concept of the equivalent load. As a result, the rectified WPT system is transformed into a series of linear systems with complex load impedances. The steady-state electric quantities can be then explicitly calculated. This enables eMHA to seamlessly work with numerical optimization algorithms to facilitate the automated design and optimization of WPT systems. An example of optimal design and optimal control of a 10 W WPT system is demonstrated. The results obtained by eMHA and FHA are also compared. A prototype of the designed circuit was constructed. The accuracy and effectiveness of eMHA are verified by experimental measurements. This paper is accompanied by a MATLAB-based analytical tool with a graphical user interface demonstrating the effects of circuit variables on electrical quantities and waveforms. [ABSTRACT FROM AUTHOR]

This paper studies the effect of the stator winding short-circuit fault on the Induction Motor performance at no-load and load condition. The comparison of the results obtained by simulation tests allowed verifying the precision of the proposed Matlab model. The simulation of three-phase induction motor performance under stator winding single-phase short circuit fault and stator winding phase-to-phase short circuit fault condition is presented. The induction machine model with balance parameters (healthy machine) such as windings inductance and resistance, and that with unbalanced parameters (unhealthy machine) due to winding short circuit fault were presented and simulated with the help of MATLAB® and the simulated results compared. The results show appreciable reduction in the performance of this machine when such faults occurred. To protect the life of the machine, there should be a protective device/circuitry to protect the machine against unbalance voltage which occurs due stator winding short circuit faults. [ABSTRACT FROM AUTHOR]