Miracle-dz/UniFAR-FTUs huggingface dataset:
An Opening Profile Recognition Method for Magnetic Flux Leakage Signals of Defect

The defect opening profile recognition is of great concern in the magnetic flux leakage (MFL) measurement technique. The detected spatial MFL signal has three components: horizontal, vertical, and normal components. Horizontal and normal component signals are commonly used to estimate the defect profile, while the vertical component has always been neglected. With the development of the high resolution and the 3-D MFL testing techniques, the vertical component signal is becoming more available. This paper analyzes the essential right-angle features of the vertical component signal, which is useful for the defect opening profile recognition. After obtaining the initial profile from the horizontal or normal component, the types of the right angle is identified from the vertical component, and the opening profile is further optimized based on these right-angle features. The opening profile recognition method is put forward in this paper to improve the accuracy of the recognition result of the defect. Both simulation and experimental tests are conducted to verify the good performance of the proposed method. Compared with the opening profiles recognized merely by the horizontal component signal, the proposed method shows better recognition results, which also validates that the vertical component signal can also be a useful information for the defect estimation.
Prediction of possible exotic states in the system

We investigate the three-body system in order to look for possible exotic states in the framework of the fixed-center approximation of the Faddeev equation. We assume the scattering of on a clusterized system , which is known to generate , or a in a clusterized system , which is shown to generate . In the case of - scattering, we find evidence of a bound state below the threshold with a mass of around 1700 MeV and a width of about 180 MeV. Considering - scattering, we obtain a bound state just below the threshold with a mass of around 1680 MeV and a width of about 160 MeV.
Fabrication of SiC nanowire thin-film transistors using dielectrophoresis

The selection of solvents for SiC nanowires (NWs) in a dielectrophoretic process is discussed theoretically and experimentally. From the viewpoints of dielectrophoresis force and torque, volatility, as well as toxicity, isopropanol (IPA) is considered as a proper candidate. By using the dielectrophoretic process, SiC NWs are aligned and NW thin films are prepared. The densities of the aligned SiC NWs are 2 μm−1, 4 μm−1, 6 μm−1, which corresponds to SiC NW concentrations of 0.1 μg/μL, 0.3 μg/μL and 0.5 μg/μL, respectively. Thin-film transistors are fabricated based on the aligned SiC NWs of 6 μm−1. The mobility of a typical device is estimated to be 13.4 cm2/(V·s).
Accurate metamodels of device parameters and their applications in performance modeling and optimization of analog integrated circuits

Techniques for constructing metamodels of device parameters at BSIM3v3 level accuracy are presented to improve knowledge-based circuit sizing optimization. Based on the analysis of the prediction error of analytical performance expressions, operating point driven (OPD) metamodels of MOSFETs are introduced to capture the circuit's characteristics precisely. In the algorithm of metamodel construction, radial basis functions are adopted to interpolate the scattered multivariate data obtained from a well tailored data sampling scheme designed for MOSFETs. The OPD metamodels can be used to automatically bias the circuit at a specific DC operating point. Analytical-based performance expressions composed by the OPD metamodels show obvious improvement for most small-signal performances compared with simulation-based models. Both operating-point variables and transistor dimensions can be optimized in our nesting-loop optimization formulation to maximize design flexibility. The method is successfully applied to a low-voltage low-power amplifier.
An SiC MOSFET and Si Diode Hybrid Three-Phase High-Power Three-Level Rectifier

The utilization of wide bandgap devices such as silicon carbide (SiC) diode and mosfet can significantly increase the power density and the efficiency of rectifier circuits. However, SiC-based circuits always suffer from the high cost of their power stage. In this paper, a highly efficient low-cost hybrid three-phase three-level rectifier is proposed. Instead of using SiC diode and Si IGBT, it consists of SiC mosfet and Si diode. It presents extremely low switching losses because the reverse recovery losses of all the Si diodes are eliminated. At the same time, the total device cost of this rectifier is much lower than the all-SiC-based rectifiers. Furthermore, half-bridge modules can be used to comprise the rectifier circuit, which makes it suitable for high-power applications. In this paper, the circuit operational analysis, simulation, and experimental results are given. A comparison is given to show the advantages of the proposed rectifier.
Acetic acid gas sensors based on Ni2+ doped ZnO nanorods prepared by using the solvothermal method

Ni2+-doped ZnO nanorods with different doping concentrations are prepared via the solvothermal method. The doped ZnO nanorods are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The amount of Ni2+ ions that enter the lattice of ZnO increases with increasing the Ni2+/Zn2+ molar ratio when the molar ratio of Ni2+/Zn2+ in the starting solution is lower than 3% and does not change obviously if the mole ratio of Ni2+/Zn2+ in the starting solution is in the range of 3–10 mol%. The effect of Ni2+ doping on the gas-sensing properties is investigated. The results reveal that the amount of Ni2+ has a great influence on the response (Ra/Rg) and the gas-sensing selectivity. The sensor based on 1 mol % Ni2+ doped ZnO nanorods (120 °C, 10 h) exhibits a high response to acetic acid vapor, in particular, the responses to 0.001 ppm and 0.01 ppm acetic acid vapor reach 1.6 and 2, respectively. The response time and the recovery time for 0.001 ppm acetic acid are only 4 s and 27 s, respectively.
ARNISMC for MLS with global positioning tracking control

: This study develops an adaptive recurrent neural network (NN) intelligent sliding-mode controller (ARNISMC) for magnetic levitation system (MLS). First, a non-linear dynamic model of the MLS is derived. Thereafter, a SM controller (SMC) method is presented to compensate for the uncertainties in the MLS. In addition, to enhance the control effort of a conventional SMC and further increase the tracking performance of the MLS, the uncertainty terms of the system dynamics can be estimated online by using an AR radial basis function NN estimator. Accordingly, the proposed controller not only offers the accurate positioning tracking control, minimises steady-state error, and improves conventional controller performance but also provides global positioning tracking control, which has not been previously reported in the literatures. It can effectively solve problems associated with typical MLS controller design. Moreover, the satisfactory tracking performance can be observed from the experimental results by adopting the proposed ARNISMC scheme.
A low-noise widely tunable Gm-C filter with frequency calibration

A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of both the Gm cells and the filter topology. A frequency tuning strategy is used by tuning both the transconductance of the Gm cells and the capacitance of the capacitor banks. To achieve accurate cut-off frequencies, an on-chip calibration circuit is presented to compensate for the frequency inaccuracy introduced by process variation. The filter is fabricated in a 0.13 μm CMOS process. It exhibits a wide programmable bandwidth from 322.5 kHz to 20 MHz. Measured results show that the filter has low input referred noise of 5.9 nV/Hz and high out-of-band IIP3 of 16.2 dBm. It consumes 4.2 and 9.5 mW from a 1 V power supply at its lowest and highest cut-off frequencies respectively.
High Q-factor micro-cavity laser: Fabrication and lasing emission properties

In this article the fabrication method and lasing emission properties of High-Q micro-cavity lasers based on High-concentration Erbium-doped silica-alumina glasses are presented in detail. The configurations of micro-cavities were spherical and/or modified toroidal forms. The lasing threshold of micro-cavity laser pumped by laser diodes was of hundred micro-watts and Q-factor of cavity had been achieved up-to 108 in experiment. The emission power of one whispering-gallery-mode (WGM) lasing from micro-cavity laser was of 0.05–0.5 mW that would be enough for applying in the quantum information and optical sensor techniques. The modified toroidal micro-cavity permits to decrease the polar-mode of WGMs, which help to obtain the single-mode emission from micro-cavity lasers.
A monolithic RF transceiver for DC-OFDM UWB

This paper presents a first monolithic RF transceiver for DC-OFDM UWB applications. The proposed direct-conversion transceiver integrates all the building blocks including two receiver (Rx) cores, two transmitter (Tx) cores and a dual-carrier frequency synthesizer (DC-FS) as well as a 3-wire serial peripheral interface (SPI) to set the operating status of the transceiver. The ESD-protected chip is fabricated by a TSMC 0.13-μm RF CMOS process with a die size of 4.5 × 3.6 mm2. The measurement results show that the wideband Rx achieves an NF of 5–6.2 dB, a max gain of 76–84 dB with 64-dB variable gain, an in-/out-of-band IIP3 of −6/+4 dBm and an input loss S11 of < −10 in all bands. The Tx achieves an LOLRR/IMGRR of −34/-33 dBc, a typical OIP3 of +6 dBm and a maximum output power of −5 dBm. The DC-FS outputs two separate carriers simultaneously with an inter-band hopping time of < 1.2 ns. The full chip consumes a maximum current of 420 mA under a 1.2-V supply.
Vegetation Image as Bayesian Predictor for Radio Propagation in Complex Environments Using Unscented Transform

Vegetation is considered a complex environment for analysis of scattering and attenuation in radio propagation phenomena. Satellite image processing can improve planning of radio systems with a vegetation attenuation predictor. In this research, the prediction is based on the correlation of more than 56% between RGB pixel values and vegetation attenuation taken from three groups of power measurements at two distinct regions of Brazil: Belo Horizonte, in the southeast region measured at 18 GHz, and Manaus at 24 GHz in the north region. The statistical analysis showed that more than 30% of the attenuation variance was due to the pixel values for each group. Using this linear correlated model between vegetation pixel RGB values and geolocated attenuation values, this work combined the unscented transform (UT) and Bayesian inference to refine the vegetation attenuation distribution. Since the necessary multiplication of Bayes prior and sampling distributions is not easily available in the UT, this paper presents a method that calculates new common sigma points and different new weights for the prior and sampling UT distributions, thus allowing the multiplication and creating the basis for a machine learning predictor tool.
Binary Channel SAW Mustard Gas Sensor Based on PdPc0.3PANI0.7 hybrid Sensitive Film

This paper discussed the working principle of binary channel surface acoustic wave (SAW) lithium niobate piezoelectric chip detecting mustard, established the mathematic model of beat frequency output Δf and the mustard gas density δ. The MEMS craft solved the parameters of the binary channel SAW chip such as its interdigital electrode number was 15∼25 couple, width and spacing were both 25µm, degree of overlapping was 2mm, fundamental frequency was 10∼35MHz, frequency-domain width was 5∼20Hz, and its back pt hot film's. According to TG-DSC thermal analysis, vacuum coating craft was adopted to solve the hybrid sensitive film forming craft parameter of PdPc0.3PANI0. 7(phthalocyanine palladium0.3Poiyaniline0.7). The micro-appearance of sensitive film was analyzed through SEM. The sensor's sensitivity and response characteristic were tested and analyzed: appear linear change, its response time is less than 5min while its recovery time is less than 8min.
Postgraduate Education Programs in Civil Engineering Based on Application-oriented University

The purpose of this paper is a discussing of the postgraduate education in civil engineering base on the education cognition rule. The author recounted the background of Chinese students’ high school education style in application-oriented university and made a comparison between China and America in order to promote the experiences and learn from each other. An example of explanation of courses and the ways students trained were discussed in this paper. Related to the future of civil engineering field, several suggestions were put forward in the conclusion.
Shannon entropy increment analysis on dynamic behavior of a biomass fluidized bed

Information theory based Shannon entropy increment analysis of the differential pressure fluctuations was successfully developed to recognize dynamic behavior of gas-solid flow and different flow patterns. Experiments were carried out in a biomass fluidized bed with cross-section of 100 mm×30 mm and height of 500 mm was carried out. Cylinder-shaped biomass particles with the size of 2.6 mm in diameter and 6 mm in length were used to as bed materials. Pressure fluctuations and flow patterns were obtained by a multi-channel differential pressure sampling system and a high-resolution digital CCD camera, respectively. It was found that both Shannon entropy and the present developed Shannon entropy increment analyses were pronounced with the flow patterns and transitions. Besies, Shannon entropy increment analyses, i.e. Shannon entropy increment and Shannon entropy increment rate, are very helpful to obtain the chaotic nature especially the change of chaotic nature with operating condition in gas-solid flow.
Design of Modified Single-Layer Double U-Type Linear to Circular Polarization Convertor

This paper proposes single-layer periodic arrays of freestanding slot frequency-selective surface (FSS) as an approach to convert linearly polarized wave to circularly polarized wave. The double U-type structure is etched on a metal plate rather than a traditional print circuit board (PCB) material. It has the characteristics of broadband and could be applied to the situation of large incident angles. Numerical simulations have been carried out, and the prototype structures have been fabricated and experimentally validated. The whole thickness is only 1 mm, and the results show that 3 dB axial ratio (AR) bandwidth is 36.6% at normal incident (16.5% at ±60°). An insertion loss of under 3 dB can be achieved within the whole AR bandwidth.
High efficiency modeling of broadband millimeter-wave CMOS FETs with gate width scalability by using pre-modeled cells

This work presents a highly efficient approach for broadband modeling of millimeter-wave CMOS FETs with gate width scalability by using pre-modeled cells. Only a few devices with varied gate width are required to be measured and modeled with fixed models, and later used as pre-modeled cells. Then a target device with the desired gate width is constructed by choosing appropriate cells and connecting them with a wiring network. The corresponding scalable model is constructed by incorporating the fixed models of the cells used in the target device and the scalable model of the connection wires. The proposed approach is validated by experiments on 65-nm CMOS process up to 40 GHz and across a wide range of gate widths.
Utilising digital light processing and compressed sensing for photo-current mapping of encapsulated photovoltaic modules

Photocurrent mapping can provide useful spatial information about the electrical and optical properties of a photovoltaic (PV) device under actual operating conditions. Although it is a well-established technique for PV cells, direct current mapping measurements of PV modules is impractical and time-consuming to be applied. One has to mechanically shade specific cells of the PV module or destructively access the cell to be measured. In this work, non-destructive, automated current mapping of encapsulated PV modules is demonstrated. A commercial Digital Light Processing (DLP) projector is utilised in order to apply compressive sampling for current mapping of PV modules. This method is non-destructive, cost effective and significantly fewer measurements are needed for acquiring a current map compared to raster scanning methods. When applying compressive sampling, a series of patterns is projected on the sample, the current response is measured for each pattern and the current map is acquired using an optimisation algorithm. Specific shading strategies, voltage bias settings and I-V curve details are investigated for optimised compressive sampling.
A Novel Inverse Synthetic Aperture Rada Imaging Method for Maneuvering Targets Based on Modified Chirp Fourier Transform

When inverse synthetic aperture radar (ISAR) imaging maneuvers targets, the azimuth echo of the target scattering point causes a Doppler frequency time-varying problem, which leads to the blurring and defocusing of the imaging results. Traditional imaging methods struggle to meet the imaging requirements for maneuvering targets due to a poor imaging effect or low efficiency. Given these challenges, a modified chirp Fourier transform (MCFT) imaging method is proposed in this paper, based on the specific relationship between the target rotation parameters and the radar echo signal parameters. Firstly, discrete chirp Fourier transform is used to quickly estimate the target’s coarse rotation ratio. Then, the minimum entropy function and gradient descent method are used to calculate the target’s accurate rotation ratio. Finally, the azimuth focusing image is accomplished by performing MCFT once on the azimuth echo signal using the accurate rotation ratio. This method avoids estimating and separating the sub-echo components one-by-one, considerably improves the imaging speed, and guarantees the best imaging quality by applying the global minimum entropy principle. The experimental results show that the proposed method effectively achieves the two-dimensional, high-quality, and fast imaging of maneuvering targets.
10 Gbit/s OWC System for Intra-Data Centers Links

We design and experimentally demonstrate a 10 Gbit/s optical wireless communication (OWC) system that can be quickly deployed and effectively used in data centers (DCs) networks. It is realized by means of commercial off-the-shelf (COTS) components, it does not need active alignment, and its 8-mm tolerance allows for simple passive alignment. We successfully tested the system from 1.5 to 3 m link distance with a target bit error ratio (BER) of ${10^{-9}}$ . This allows the realization of an array of transceivers to further increase the capacity. Finally, the system power consumption (10 pJ/bit) is much lower than its alternatives. These results demonstrate that the proposed OWC system can be a viable solution for future DC networks.
An empirical study of purchase behaviour on social platforms

Purpose Social media users’ purchasing behaviour is yet to be fully understood by research. The purpose of this paper is to investigate how purchase intention is affected by social media user traits, cognitive factors (such as perceived control and trust) and individual beliefs, such as risk propensity and trustworthiness. Design/methodology/approach The authors propose and empirically test a model of purchase intention on social platforms. The study of over 500 active social media users finds the links between risk propensity, trust, technical efficacy and perceived control and explores the moderating effect of age and gender. Findings Purchase intention on social platforms is influenced by demographic factors, cognitive factors and beliefs. Both age and gender moderate the effects of beliefs and cognitive factors: age is a determinant of purchase intention for men, while beliefs are significant for younger women and cognitive factors are significant for older women. Research limitations/implications This study involved a cross-sectional design via online survey of social networking users. Gender differences in purchase intentions are found which are, in turn, influenced by age. Further empirical testing of social purchase intention could include less experienced users or non-users. Practical implications The results of this study provide guidance for SNS providers and technology developers in social networking commerce in terms of the different drivers of purchase intention. Originality/value Social media users’ purchasing behaviour is yet to be fully understood. The study shows that purchase intention antecedents vary between genders and age groups of users. The identified connection between users’ perceptions of social networking sites (SNS) usage of personal information and purchase behaviour has an impact on the likelihood of user engagement in social transactions.
Built-in electric field thickness design for betavoltaic batteries

Isotope source energy deposition along the thickness direction of a semiconductor is calculated, based upon which an ideal short current is evaluated for betavoltaic batteries. Electron-hole pair recombination and drifting length in a PN junction built-in electric field are extracted by comparing the measured short currents with the ideal short currents. A built-in electric field thickness design principle is proposed for betavoltaic batteries: after measuring the energy deposition depth and the carrier drift length, the shorter one should then be chosen as the built-in electric field thickness. If the energy deposition depth is much larger than the carrier drift length, a multi-junction is preferred in betavoltaic batteries and the number of the junctions should be the value of the deposition depth divided by the drift length.
M supergravity and abelian semigroups

A gauge theory for the M algebra in eleven-dimensional spacetime is put forward. The gauge-invariant Lagrangian corresponds to a transgression form. This class of Lagrangians modifies Chern-Simons theory with the addition of a regularizing boundary term.The M algebra-invariant tensor required to define the theory comes from regarding the algebra as an abelian semigroup expansion of the orthsymplectic algebra osp (32|1). The explicit form of the Lagrangian is found by means of a transgression-specific subspace separation method. Dynamical properties are briefly analyzed through an example. The equations of motion are found to place severe constraints on the geometry, which might be partially alleviated by allowing for nonzero torsion.
Study on the reaction process of alkali‐activated carbonatite by means of polarizing microscope and digital holographic microscope technology

The reaction process of alkali‐activated carbonatite and the dissolution rate of carbonatite with different content of MgO in water glass solution were studied in this paper by means of in‐situ technologies, that is, polarizing microscope (PM) and digital holographic microscope (DHM). The volume change of carbonatite particles as a function of dissolution time was also quantified by using DHM. The results show that the dissolution rate of carbonatites decreases as the increase of Mg content (from 0 to 21.6 wt. %) in carbonatites. The average dissolution rate of carbonatite with a MgO content of 11.37 wt. % in water glass (M = 1.6, c = 35%) is 75.33 μm3/h within the first 12 hr of dissolution. Both dedolomitization and alkali‐silica reaction are present in the alkali‐activated carbonatite system. The Mg‐carbonatite tends to dedolomitize first before it reacts with silicate ions. It explains why the Mg‐rich carbonatite has a lower dissolution rate in water glass.