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In the paper, the novel topology of the resonant DC link three-level soft-switching inverter is proposed to reduce switching losses and improve the efficiency of three-level inverter at high switching frequency. Symmetrical auxiliary resonant circuits are set in the DC link of three-level hard-switching inverter. Moreover, the terminal voltage of the resonant capacitors between the DC buses periodically drops to zero via the resonance of auxiliary circuits. Furthermore, under such condition, the main switches of the three-level inverter would be operated, in order to achieve zero-voltage switching. Based on the equivalent circuits in different operating modes, the paper analyses the working process of the soft-switching inverter in detail. In addition, a 3 kW laboratory prototype of resonant DC link three-phase three-level soft-switching inverter is built. The experimental results show that the main switches and auxiliary switches of the inverter are operated under soft-switching conditions, and the efficiency is significantly improved compared with the three-level hard-switching inverter. Therefore, the proposed topology can effectively reduce switching losses and prove to be more practical in engineering. [ABSTRACT FROM AUTHOR]

This article is an interesting substrate material for environmental-friendly printable electronics. In this study, screen-printed RFID tags on paper substrate are examined. Their reliability was tested with low temperature, high temperature, slow temperature cycling, high temperature and high humidity and water dipping test. Environmental stresses affect the tag antenna impedance, losses and radiation characteristics due to their impact on the ink film and paper substrate. Low temperature, temperature cycling and high humidity did not have a radical effect on the measured parameters: threshold power, backscattered signal power or read range of the tags. However, the frequency response and the losses of the tags were slightly affected. Exposure to high temperature was found to even improve the tag performance due to the positive effect of high temperature on the ink film. The combined high humidity and high temperature had the most severe effect on the tag performance. The threshold power increased, backscattered power decreased and the read range was shortened. On the whole, the results showed that field use of these tags in high, low and changing temperature conditions and high humidity conditions is possible. Use of these tags in combined high-humidity and high-temperature conditions should be carefully considered. [ABSTRACT FROM PUBLISHER]

An auxiliary switching device is usually set on the DC bus of the resonant DC link inverter, which restricts the efficiency of the inverter and is also one of the reasons for its not extensive application and promotion in the high-power field. To solve the problem, auxiliary circuits and DC bus of the resonant DC link soft-switching inverter designed in this paper are connected in parallel, and auxiliary switching devices and resonant elements are not connected in series on the DC bus, which help to improve the efficiency and reduce the power losses of the auxiliary resonant circuits. Based on the equivalent circuits in different operating modes, the paper analyzes the working process of the soft-switching inverter, soft-switching realization conditions and design rules. A 10 kW laboratory prototype is built, and through the comparison of the experimental results from it and the hard-switching inverter, it is shown that the efficiency improvement value of the designed inverter at full load is higher than that at light load. Therefore, the soft-switching inverter designed in this paper is conductive to reducing the power losses of the auxiliary resonant circuits and ensuring the efficient use of the electric energy. [ABSTRACT FROM AUTHOR]

Approximate computing is an emerging paradigm that can tolerate some loss of accuracy to improve the energy consumption and design complexity. Multiplication is one of the important computational components in various digital signal processing (DSP) applications. Improvement of multipliers, as the building blocks of an approximate computing systems, has received significant attention. Compressors are key elements in an approximate multiplier to have an optimal design with high performance. This paper proposes an approximate/exact 4–2 compressor and an exact 5–2 compressor in carbon nanotube field-effect transistors (CNTFET) technology for utilisation in an approximate multiplier. Four efficient designs for utilising the proposed compressors are introduced and analysed for a Wallace multiplier. All of the proposed circuits are analysed in 32 nm CNTFET Stanford technology and are simulated by HSPICE. In addition, as an image processing application of approximate multipliers, this paper compares the quality metrics of the image multiplication for the proposed designs and previously presented approximated multipliers. For example, the proposed schemes provide excellent results in structural similarity index up to 99%, and peak signal-to-noise ratio more than 45 dB. Also, it uses figure of metric (FOM) that includes the accuracy and quality metrics of the approximate multipliers. The simulation results demonstrate the efficiency of proposed designs. [ABSTRACT FROM AUTHOR]

This paper describes a printed Thai character recognition method which uses topological properties. The recognition system is divided into two stages. In the rough classification stage, a thinning technique is applied to eliminate noise and fine features. The thinned characters are separated into cluster domains by using a linear decision function based on the height and width of each character. In the fine classification stage, the ‘connected numbers’ of points in the character pattern are computed. Topological properties are then used to distinguish between the characters. [ABSTRACT FROM AUTHOR]

A method of comparing the basic performance of electron guns is described. The method is applied to some recently computed results on two versions of an electron gun which has a hairpin-filament cathode.
In an interesting and useful paper by Worster (1979 a), hereafter referred to as JW, computed results are given relating to two electron guns. When the performance of the guns was compared it was concluded that one gun was better than the other in all respects. However, in making the comparison the electron beam divergence was not taken into account. Although the method of comparison used in JW may, of course, be satisfactory for some purposes, the computed results in JW are comprehensive enough to provide information for an alternative method of comparison which includes beam divergence. Such an alternative method, described in this note, leads to different conclusions. [ABSTRACT FROM AUTHOR]

This paper presents simulation analysis of an inverter made from non-aligned double gate field effect transistors (NADGFETs) in Sub-100 nm regime. The inverter consists of n-channel NADGFET and p-channel NADGFET device with a channel length of 40 nm and 50% non-alignment between gate and source/drain. The response of the inverter was tested by a combination of gate dielectric constant (k) and metal work function (ϕ). Three gate dielectrics namely, SiO2 (k = 3.9), Si3N4 (k = 7.2), HfO2 (k = 24), and three metal work function namely tungsten (ϕ = 4.5 eV), molybdenum (ϕ = 4.75 eV), gold (ϕ = 5 eV), were considered in the NADGFET inverter. This paper defines a kϕ index as characterising parameter to explore the best response from inverter configuration with minimum propagation delay, and minimum power consumption at super-high frequency. The paper proposes to analyse the NADGNFET device, in term of ION current, ION/IOFF ratio, cut-off frequency, and gate delay. And observes that low k material with moderate metal work function gives best response. The work then simulates the inverter and group the results into voltage transfer curve (VTC), transient response, and power dissipation category. The result shows that when inverter was subjected to high frequency, all the kϕ combination responds good, however when the inverter was subjected to super-high frequency, the low value of kϕ combination performs well. Thus, the result concludes that SiO2-M2 combination will be best selection to get minimum propagation delay and dynamic power dissipation by the inverter. The test strategy presented in this paper on the basis of kϕ index can serve as benchmark to test inverter device at super-high frequency. [ABSTRACT FROM AUTHOR]

In this paper, the radial basis function neural network based on the orthogonal least squares (OLS-RBFNN) method is proposed for the first time for the calibration of the six-port receiver, which realises six-port accurate reception in the true sense. This algorithm overcomes the problems of an ageing circuit, narrow working frequency band and nonlinearity of the six-port receiver hardware. The RBFNN is a three-layer forward network, including an input layer, a hidden layer and an output layer. The transformation function of the hidden layer is the radial basis function. A six-port receiver test platform with an operating frequency band of 2.0–8.0 GHz is built to verify the performance of the six-port receiver based on OLS-RBFNN. The test signal is a 16-QAM signal with different bandwidths and different frequency bands. The test indicator uses error vector magnitude (EVM)， which represents the error between the received signal and the ideal signal sent. At last, the EVM of all tested data is less than 1.07%, and the best EVM is 0.57%. Therefore, the calibration accuracy of the OLS-RBFNN proposed in this paper is very high. [ABSTRACT FROM AUTHOR]

Examines the characteristics of travelling waves along the non-linear transmission lines for monolithic integrated circuits. Analysis of slow-wave structures like MIS and Schottky-barrier strip lines; Examination of suitable equivalent circuits leading to characteristic wave equations; Parameters of the non-linearity, dispersion and dissipation and the boundary conditions of practical devices.

Examines the use of distributed, monolithic travelling-wave amplifiers. Guidance on reducing amplifier noise by rendering dipole-domain-generated noise contributed by the individual field effect transistor (FET); Use of insulated gate FET to permit higher gate breakdown voltage operation in the accumulation mode; Reduction of even harmonics and the improvement of efficiency.

Discusses the statistical properties of randomly generated boolean functions. Effect of prime implicant errors in the minimization algorithms; Relationship between the number of variables in the boolean expression on the k-subcube probability to be a prime implicant.

Power converters enhance the DC-AC power supply by using multi-level inverters based on switched capacitor technology. The voltage stress on the switches in switched capacitor-based multi-level inverters decreases as the number of switches rises, and vice versa when the number of switches falls. This paper suggests a quadruple boost nine-level inverter based on a switched capacitor with a single voltage source to address this issue. Only nine switches are used in the suggested architecture to implement the inverter with two diodes and two capacitors. Since the diodes and capacitors are linked to the low voltage input side, the total voltage stress of the inverter is kept low even at the elevated for quadruple boost output voltage. The theoretical study, computations, and design parameters of the nine-level inverter are presented in this paper. The switching specifics of the seven-level boost extension topology are also reported in this work. Simulations and laboratory tests on a 120 W inverter prototype have confirmed the viability of the suggested topology. [ABSTRACT FROM AUTHOR]

Due to the intermittent and unstable nature of PV systems, maximum power point tracking (MPPT) of PV systems is necessary in practice. At the same time, PV cells are also shaded by objects such as trees and houses in the environment causing local shadows, so the Lévy flight particle swarm optimisation (LFPSO) is proposed in this paper. The random walk process of Lévy flight is added to the particle swarm optimisation (PSO) to increase the diversity of the search, which can avoid falling into local optimal solutions. The experimental simulation results show that the algorithm proposed in this paper can still accurately track the global maximum power in the case of partial shading, which well avoids falling into the local maximum power. The performance is much higher than the traditional maximum power point tracking algorithm, which improves the efficiency of the PV system. [ABSTRACT FROM AUTHOR]

This paper proposes an efficient design of Hamming (11, 7) encoder utilising Full Swing-Gate Diffusion Input (FS-GDI) approach in 65 nm technology nano-size node. The proposed design of Hamming codes aims to improve the power and area efficiency through reducing of transistors count by employing power-efficient logic style. Encoding circuits of Hamming code (11, 7) and (7, 4) are designed using the various traditional and proposed approaches. The amount of consumed power, delay time, Power Delay Product (PDP) and hardware simplicity are employed as a metrics for evaluating the efficiency of the proposed designs of encoding circuits. The simulation experiments are executed utilising Cadence Virtuoso simulator package. These experiments revealed that the proposed designs of Hamming encoding circuits achieve delay time reduction by 50.91% and 20% for Hamming codes (7, 4) and (11, 7), respectively. Also, hardware (H/W) simplicity and area efficiency of the circuits are improved by 50% compared to CMOS-based circuits. From the results analysis, the proposed FS-GDI based Hamming encoding circuits achieve efficient power and delay optimising. Hence, the power consumption, delay and area in communications systems and DSP circuits due to encoding process are reduced. The whole performance of DSP circuits can be more power/area efficient. [ABSTRACT FROM AUTHOR]

In this paper, we present a design method for a highly efficient retrodirective array (RDA)-based microwave power transfer (MPT) system for the mMTC scenario, and evaluate its characteristics through experiments. Long-range wireless power transfer is required to effectively support the mMTC situation. RDA-based MPT controls and tracks the power beam towards the device within a certain range and it enables efficient power transfer. The overall link budget analysis is examined first and the required antenna gain is calculated. The required antenna gain can be secured using multiple-antenna modules. So, it is possible to design an RDA-based MPT system. In this paper, we implement a reduced RDA-based MPT system and evaluate its characteristics to confirm the feasibility of this design method. Through experiments, it has been confirmed that additional gain can be secured by using multiple antenna modules, and the RDA function can be effectively operated to effectively make a power beam in the direction of the power receiver. Conclusively, the gain of about 2.2dB increased whenever the number of antennas is doubled. The experimental results also show that the RDA-based MPT system designed in this paper is capable of adaptive power beamforming from −30 degrees to 30 degrees. [ABSTRACT FROM AUTHOR]

Comments concerning on inconsistencies in the analysis of alpha-particle scattering. Validity of the field concept; Relation between the laws of physics and relativity; Information on the theory of electromagnetic.

In this paper, a Dickson-based RF-DC (Radio frequency power to direct current power) rectifier for energy harvesting system is designed. Dickson double-voltage structure, voltage-dividing structure and switching transistors are integrated in the system to fulfil the synchronous rectifying function, which can upgrade PCE (Power Conversion Efficiency) value, reduce the threshold voltage and decrease the leakage current, etc.. The simulation is conducted on the designed synchronous rectifier for energy harvesting of 900 MHz signal. It shows that when the input voltage $${V_{IN}} = 1V$$ V IN = 1 V , the peak output DC voltage can be stabilised at 1.8 V with the assistance of LDO (Low dropout) regulator, while the reverse leakage current is below 20 µA and the PCE value reaches 58%. The designed rectifier is assembled and tested in the paper. Both the simulation and testing results demonstrate the feasibility of the proposed synchronous rectifier. [ABSTRACT FROM AUTHOR]

This paper presents the performance analysis of a five-level T-type multilevel inverter (MLI) based six-phase induction motor drive (SPIMD) for high-power industrial applications. In the adopted T-type MLI, the sensorless self-capacitor voltage balancing control is designed, which controls the voltage across the capacitor at half the magnitude of the direct current (DC) source value, creating a symmetrical five-level output voltage waveform. Moreover, self-capacitor voltage balancing control reduces complexity and improves system performance. The SPIMD with distributed neutral is taken as the load, and the whole system is simulated using MATLAB/Simulink software. The system's performance is determined by considering the power loss and efficiency. This paper also presents a comparative performance analysis of the adopted T-type, cascaded h-bridge (CHB) and Flying Capacitor (FC) MLI-based SPIMD. Finally, a prototype is developed as a proof of concept and tested experimentally to validate the analytical development of the adopted system. [ABSTRACT FROM AUTHOR]