Improving Text-Independent Chinese Writer Identification with the Aid of Character Pairs

2018 ◽  
Vol 33 (02) ◽  
pp. 1953001
Author(s):  
Yu-Jie Xiong ◽  
Li Liu ◽  
Shujing Lyu ◽  
Patrick S. P. Wang ◽  
Yue Lu
Keyword(s):  
Displacement Field ◽  
High Frequency ◽  
Experimental Results ◽  
Writer Identification ◽  
Writing Style ◽  
Candidate List ◽  
Identification Scheme ◽  
Individual Character ◽  
Text Content ◽  
Global Writing

Text-independent Chinese writer identification does not depend on the text content of the query and reference handwritings. In order to deal with the uncertainty of the text content, text-independent approaches usually give special attention to the global writing style of handwriting, rather than the properties of each individual character or word. Thanks to the existence of high-frequency characters, some characters probably appear in both the query and reference handwritings in most cases. If character images in the query handwriting are similar to those in the reference handwriting, this query handwriting and the corresponding reference handwriting are very likely to be written by the identical writer. In this paper, we exploit the above characteristic to improve the performance of Chinese writer identification. We first present an identification scheme using edge co-occurrence feature (ECF). Then, we detect the character pairs in the query and reference handwritings using a two-step framework and propose the displacement field-based similarity (DFS) to determine whether a character pair is written by the identical writer. The character pairs help to re-rank the candidate list obtained by text-independent ECF-based similarity and finally decide the writer of the query handwriting. The proposed method is evaluated on the HIT-MW and CASIA-2.1 datasets. Experimental results demonstrate that our proposed method outperforms the existing ones, and its Top-1 accuracy on the two datasets reaches 97.1% and 98.3%, respectively.

scholarly journals Synchronous Machine Winding Modeling Method Based on Broadband Characteristics

2021 ◽  
Vol 11 (10) ◽  
pp. 4631
Author(s):  
Yu Chen ◽  
Xiaoqing Ji ◽  
Zhongyong Zhao
Keyword(s):  
Equivalent Circuit ◽  
High Frequency ◽  
Equivalent Circuit Model ◽  
Black Box ◽  
Synchronous Machine ◽  
Circuit Model ◽  
Modeling Method ◽  
Experimental Results ◽  
Box Model ◽  
Impedance Curve

The accurate establishment of the equivalent circuit model of the synchronous machine windings’ broadband characteristics is the basis for the study of high-frequency machine problems, such as winding fault diagnosis and electromagnetic interference prediction. Therefore, this paper proposes a modeling method for synchronous machine winding based on broadband characteristics. Firstly, the single-phase high-frequency lumped parameter circuit model of synchronous machine winding is introduced, then the broadband characteristics of the port are analyzed by using the state space model, and then the equivalent circuit parameters are identified by using an optimization algorithm combined with the measured broadband impedance characteristics of port. Finally, experimental verification and comparison experiments are carried out on a 5-kW synchronous machine. The experimental results show that the proposed modeling method identifies the impedance curve of the circuit parameters with a high degree of agreement with the measured impedance curve, which indicates that the modeling method is feasible. In addition, the comparative experimental results show that, compared with the engineering exploratory calculation method, the proposed parameter identification method has stronger adaptability to the measured data and a certain robustness. Compared with the black box model, the parameters of the proposed model have a certain physical meaning, and the agreement with the actual impedance characteristic curve is higher than that of the black box model.

scholarly journals PCDRN: Progressive Cascade Deep Residual Network for Pansharpening

2020 ◽  
Vol 12 (4) ◽  
pp. 676 ◽  
Author(s):  
Yong Yang ◽  
Wei Tu ◽  
Shuying Huang ◽  
Hangyuan Lu
Keyword(s):  
High Resolution ◽  
Loss Function ◽  
High Frequency ◽  
Experimental Results ◽  
Superior Performance ◽  
Residual Network ◽  
High Quality ◽  
Convolution Approach ◽  
Visual Assessments ◽  
Coarse To Fine

Pansharpening is the process of fusing a low-resolution multispectral (LRMS) image with a high-resolution panchromatic (PAN) image. In the process of pansharpening, the LRMS image is often directly upsampled by a scale of 4, which may result in the loss of high-frequency details in the fused high-resolution multispectral (HRMS) image. To solve this problem, we put forward a novel progressive cascade deep residual network (PCDRN) with two residual subnetworks for pansharpening. The network adjusts the size of an MS image to the size of a PAN image twice and gradually fuses the LRMS image with the PAN image in a coarse-to-fine manner. To prevent an overly-smooth phenomenon and achieve high-quality fusion results, a multitask loss function is defined to train our network. Furthermore, to eliminate checkerboard artifacts in the fusion results, we employ a resize-convolution approach instead of transposed convolution for upsampling LRMS images. Experimental results on the Pléiades and WorldView-3 datasets prove that PCDRN exhibits superior performance compared to other popular pansharpening methods in terms of quantitative and visual assessments.

Comb Shaped Triple Band Microstrip Antenna for Wireless Communication

2021 ◽  
Vol 9 (4) ◽  
pp. 379-382
Keyword(s):  
Dielectric Constant ◽  
Wireless Communication ◽  
High Frequency ◽  
Microstrip Antenna ◽  
Return Loss ◽  
Experimental Results ◽  
High Frequency Structure Simulator ◽  
Frequency Structure ◽  
Triple Band

A comb shaped microstrip antenna is designed by loading rectangular slots on the patch of the antenna. The antenna resonating at three different frequencies f1 = 5.35 GHz, f2 = 6.19 GHz and f3= 8.15 GHz. The designed antenna is simulated on High Frequency Structure Simulator software [HFSS] and the antenna is fabricated using substrate glass epoxy with dielectric constant 4.4 having dimension of 8x4x0.16 cms. The antenna shows good return loss, bandwidth and VSWR. Experimental results are observed using Vector Analyzer MS2037C/2.

Analysis and Optimization of Conformal Patch Excited Wideband DRA of Several Shapes

Frequenz ◽  
2018 ◽  
Vol 72 (5-6) ◽  
pp. 197-208 ◽  
Author(s):  
Pramod Kumar ◽  
Santanu Dwari ◽  
Shailendra Singh ◽  
Ashok Kumar ◽  
N. K. Agrawal ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Frequency Spectrum ◽  
High Frequency ◽  
Unit Volume ◽  
Experimental Results ◽  
Impedance Bandwidth ◽  
High Frequency Structure Simulator ◽  
Triangular Shape ◽  
Operating Band ◽  
Peak Gain

AbstractIn this paper various shapes of DR antennas excited by common feed have been proposed and successfully implemented for wideband applications. Proposed structures are Hemispherical, Arrow-shaped and Triangular DRA, while common excited feed is inverted trapezoidal conformal patch. These shapes of DR offer significant optimization in several parameters such as impedance bandwidth, peak gain and bandwidth per unit volume of the antenna. By using inverted trapezoidal patch feed mechanism an impedance bandwidth (VSWR<2) of about 63 % for hemispherical shape, 66 % for arrow shape, and 72 % for triangular shape DRA has been achieved with maximum bandwidth per unit volume. Proposed wideband DRAs i. e. triangular, hemispherical, and arrow shapes of DR antennas cover almost complete C-band (4 GHz–8 GHz) frequency spectrum of microwave. The average peak gain within the operating band for hemispherical, arrow, and triangular shape DRA are about 5, 5.4, and 5.5 dB respectively. A comparative analysis of proposed structures for various antenna parameters has been analyzed by HFSS (High-Frequency Structure Simulator) and validated by experimental results.

scholarly journals Recognition of Compromised Accounts on Twitter

2015 ◽  
Author(s):  
Rodrigo Igawa ◽  
Alex Almeida ◽  
Bruno Zarpelão ◽  
Sylvio Jr
Keyword(s):  
Social Networks ◽  
Online Social Networks ◽  
Experimental Results ◽  
Writing Style ◽  
Authorship Verification

In this work, we propose an approach for recognition of compromised Twitter accounts based on Authorship Verification. Our solution can detect accounts that became compromised by analysing their user writing styles. This way, when an account content does not match its user writing style, we affirm that the account has been compromised, similar to Authorship Verification. Our approach follows the profile-based paradigm and uses N-grams as its kernel. Then, a threshold is found to represent the boundary of an account writing style. Experiments were performed using a subsampled dataset from Twitter. Experimental results showed that the developed model is very suitable for compromised recognition of Online Social Networks accounts due to the capability of recognize user styles over 95% accuracy.

An 8kW LLC resonant converter in plasma power supply based on SiC power devices for efficiency improvement

Circuit World ◽  
2019 ◽  
Vol 45 (4) ◽  
pp. 181-188
Author(s):  
Zhenmin Wang ◽  
Wenyan Fan ◽  
Fangxiang Xie ◽  
Chunxian Ye
Keyword(s):  
Silicon Carbide ◽  
Power Supply ◽  
High Frequency ◽  
Experimental Results ◽  
Switching Frequency ◽  
Resonant Converter ◽  
Plasma Power ◽  
Power Devices ◽  
Content Type ◽  
Llc Resonant Converter

Purpose This paper aims to present an 8 kW LLC resonant converter designed for plasma power supply with higher efficiency and lighter structure. It presents how to solve the problems of large volume and weight, low performance and low efficiency of traditional plasma power supply. Design/methodology/approach At present, conventional silicon (Si) power devices’ switching performance is close to the theoretical limit determined by its material properties; the next-generation silicon carbide (SiC) power devices with outstanding advantages can be used to optimal design. This 8 kW LLC resonant converter prototype with silicon carbide (SiC) power devices with a modulated switching frequency ranges from 100  to 400 kHz. Findings The experimental results show that the topology, switching loss, rectifier loss, transformer loss and drive circuit of the full-bridge LLC silicon carbide (SiC) plasma power supply can be optimized. Research limitations/implications Due to the selected research object (plasma power supply), this study may have limited universality. The authors encourage the study of high frequency resonant converters for other applications such as argon arc welding. Practical implications This study provides a practical application for users to improve the quality of plasma welding. Originality/value The experimental results show that the full-bridge LLC silicon carbide (SiC) plasma power supply is preferred in operation under conditions of high frequency and high voltage. And its efficiency can reach 98%, making it lighter, more compact and more efficient than previous designs.

Experimental and numerical determination of mode II fracture toughness of woven composites verified through unidirectional composite test data

2019 ◽  
Vol 27 (9) ◽  
pp. 557-566
Author(s):  
Rowan Healey ◽  
Nabil M Chowdhury ◽  
Wing Kong Chiu ◽  
John Wang
Keyword(s):  
Fracture Toughness ◽  
Displacement Field ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Experimental Results ◽  
Woven Composites ◽  
Mode Ii ◽  
Numerical Comparison ◽  
J Integral ◽  
Mode Ii Fracture Toughness

Due to the increase in prevalence of fibre-reinforced polymer matrix composites (FRPMC) in aircraft structures, the need for adaption of failure prediction tools such as fatigue spectra has become more pertinent. Fracture toughness is an important measure with regard to fatigue, while adequate techniques and an ASTM standard for unidirectional FRPMC exist, there are mixed opinions when investigating woven FRPMC. This study describes a three-dimensional finite element model developed to assist in determining the mode II interlaminar fracture toughness ( GIIc) of fibre-reinforced woven composites, validated by an experimental and numerical comparison of GIIc determination for unidirectional FRPMC. Experimental testing mirroring the ASTM D7905 resulted in a measure of 1176 J m−2for the unidirectional specimen, while comparisons made with the literature achieved an average value of 1459.24 J m−2or the woven specimen. Three numerical methods were employed due to their prominence in the literature: displacement field, virtual crack closure techniques and the J integral. Both the J integral and the displacement field three-dimensional models produced satisfactory unidirectional GIIc estimates of 1284 and 1116.8 J m−2, respectively. Displacement field had a 5% uncertainty in GIIc when compared with experimental results, while J integral had an approximately 8.5% uncertainty. Extending the analysis to the woven specimens, values of 1302.8 and 1465.3 J m−2were obtained from J integral and displacement field methods, respectively, both within 10% of the experimental values. Hence, numerically determined unidirectional GIIc values were verified with experimental results, leading to the successful employment and extension to woven composites which displayed similar agreement.

scholarly journals Nondestructive Evaluation of Solids Based on Deformation Wave Theory

2020 ◽  
Vol 10 (16) ◽  
pp. 5524
Author(s):  
Sanichiro Yoshida ◽  
Conor McGibboney ◽  
Tomohiro Sasaki
Keyword(s):  
Field Theory ◽  
Solitary Wave ◽  
Displacement Field ◽  
Wave Equations ◽  
Continuous Wave ◽  
Experimental Results ◽  
Electronic Speckle Pattern Interferometry ◽  
Wave Characteristics ◽  
Spatiotemporal Characteristics ◽  
Deformation Stage

The application of a recent field theory of deformation and fracture to nondestructive testing (NDT) is discussed. Based on the principle known as the symmetry of physical laws, the present field theory formulates all stages of deformation including the fracturing stage on the same theoretical basis. The formalism derives wave equations that govern the spatiotemporal characteristics of the differential displacement field of solids under deformation. The evolution from the elastic to the plastic stage of deformation is characterized by a transition from longitudinal (compression) wave to decaying longitudinal/transverse wave characteristics. The evolution from the plastic to the fracturing stage is characterized by transition from continuous wave to solitary wave characteristics. Further, the evolution from the pre-fracturing to the final fracturing stage is characterized by transition from the traveling solitary wave to stationary solitary wave characteristics. In accordance with these transitions, the criterion for deformation stage is defined as specific spatiotemporal characteristics of the differential displacement field. The optical interferometric technique, known as Electronic Speckle-Pattern Interferometry (ESPI), is discussed as an experimental tool to visualize those wave characteristics and the associated deformation-stage criteria. The wave equations are numerically solved for the elastoplastic stages, and the resultant spatiotemporal behavior of the differential displacement field is compared with the experimental results obtained by ESPI. Agreement between the experimental and numerical results validates the present methodology at least for the elastoplastic stages. The solitary wave characteristics in the fracturing stages is discussed based on the experimental results and dislocation theory.

HIGH FREQUENCY AHARONOV–BOHM OSCILLATIONS IN CARBON NANOTUBES

2003 ◽  
Vol 17 (04) ◽  
pp. 159-165
Author(s):  
LINFENG YANG ◽  
JIE JIANG ◽  
JINMING DONG
Keyword(s):  
Carbon Nanotubes ◽  
Magnetic Flux ◽  
High Frequency ◽  
Quantum Interference ◽  
Weak Localization ◽  
Experimental Results ◽  
Single Wall Carbon Nanotubes ◽  
Multiple Cycle ◽  
Breaking Length ◽  
Aharonov Bohm

We give a multiple-cycle quantum interference model and obtain magnetoresistance (MR) expression in the framework of the weak localization. The MR expression based upon finite phase-breaking length Lφ can explain well several experimental results about distinct negative magnetoresistance of carbon nanotubes. The higher-order oscillation peaks with magnetic flux exist in the MR can also be explained by our model. And a new method to measure the phase-breaking length Lφ of the single-wall carbon nanotubes has been proposed.

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