Miracle-dz/UniFAR-FTUs huggingface dataset:
Dynamic selective harmonic elimination of a three-level inverter used for static VAr compensation

The paper investigates the harmonic interaction between the AC and DC sides of a 3-level inverter used as a static synchronous VAr compensator (STATCOM). It is illustrated that due to the 3rd harmonic voltage across each DC side capacitor, the conventional selective harmonic elimination modulation (SHEM) may not actually eliminate the target harmonics when the system is on load. A new modulation method, which dynamically adjusts the switching angles according to the operating point, is proposed to overcome this difficulty. The proposed method is verified using simulation and experimental test.
Context Residual Attention Network for Remote Sensing Scene Classification

Remote sensing image scene classification has attracted much attention due to its wide application. In this letter, a new end-to-end attentive context network under the guidance of human visual system has been proposed. The network can focus on some critical regions of the image selectively and then extract high-level feature information so as to generalize the whole image. The contributions of this letter are as follows: 1) a novel attention structure which expresses the attention of image by stacking attention modules is designed and 2) the context information of the image is used to make a holistic analysis of the attention mechanism on the basis of the top–down feedforward structure. Experiments performed on several datasets demonstrate that the proposed framework can obtain outstanding performance compared with the state-of-the-art approaches.
Individual Blade Pitch Control for Load Reduction

If a pitch-regulated wind turbine has individual pitch actuators for each blade, the possibility arises to send different pitch angle demands to each blade. The possibility of using this as a way of reducing loads has been suggested many times over the years, but the idea has yet to gain full commercial acceptance. There are a number of reasons why this situation may be set to change, and very significant load reductions can result. Copyright © 2002 John Wiley & Sons, Ltd.
An Image Segmentation Method of Underwater Targets Based on Active Contour Model

The underwater images are disturbed with low signal to noise ratio and edge blur, because there are the light scattering and absorption effects. If the traditional thresholding method is used directly to segment underwater images, it will usually lead to be less effective to process underwater images. An image segmentation method of underwater target based on active contour model was proposed in this paper. Firstly, using Canny edge detection algorithm to detect the edges of the original image to obtain the information of a crude outline, then the algorithm based on C-V active contour model to segment underwater target images was addressed. The images processing results based on threshold segmentation method and C-V model method were compared. Experiments demonstrate the effectiveness of the proposed algorithm for underwater targets images segmentation.
Prediction of the mechanisms of action of Yinqiao powder in Influenza: A network pharmacology study

Objective To predict the potential target and pharmacological mechanism of Yinqiao Powder (YQP) in the treatment of influenza. MethodsThe symptom mapping (SymMap) platform was retrieved to obtain the targets of all herbs in YQP. Influenza-related targets were obtained using the Comparative Toxicogenomics Database (CTD) and DisgeNet database. The String database was used to construct the protein-protein interaction (PPI) network; the Metascape platform was used to enrich key targets by GeneOntology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Data were visualized and analyzed using software such as Bioinformatics, Edrawmax, and Cytoscape. Results A total of 263 potential targets of YQP for influenza treatment were screened. There are 256 nodes and 3697 edges in the PPI network. The key targets of the PPI network are AKT1, TP53, INS, IL6, MAPK3, VEGFA, etc. The results of Go enrichment showed that YQP can interfere with biological processes such as response to toxic substance, cytokine-mediated signaling pathway, response to lipopolysaccharide, response to extracellular stimulus, and positive regulation of cell death. The results of KEGG pathway enrichment showed that YQP could interfere with the infection process of the influenza virus by intervening PI3K/Akt, TNF, IL-17, MAPK, and other pathways. Conclusion This study reflects the multi-target and multi-pathway action characteristics of Yinqiaosan, and its mechanism of action in the treatment of influenza may be related to the regulation of PI3K-Akt, NF-kappa B, and MAPK signaling pathways. However, further experimental studies are needed to verify the specific mechanism of YQP.
UHF RFID near field reader antenna for item level applications

A UHF band near‐field antenna using microstrip lines and stubs for tagging stacked tags in a smart table is presented. It is shown that a suitable near‐field reader antenna can be designed from signal lines, ground lines, and several stubs to generate coupled electric and magnetic fields. The proposed near‐field reader antenna satisfactorily operates in a UHF radio frequency identification (RFID) smart table, and the measurements show that the antenna is capable of detecting 200 stacked tags in a reading area of 200 mm × 190 mm and achieves a detection rate of 97% when the tags are stacked in a smart table. The proposed UHF RFID smart table is successfully implemented for casino chip management. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1116–1119, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25115
Nonmechanical beam steering using optical phased arrays

Beam steering is an enabling technology for establishment of ad hoc communication links, directed energy for infrared countermeasures, and other in-theater defense applications. The development of nonmechanical beam steering techniques is driven by requirements for low size, weight, and power, and high slew rate, among others. The predominant beam steering technology currently in use relies on gimbal mounts, which are relatively large, heavy, and slow, and furthermore create drag on the airframes to which they are mounted. Nonmechanical techniques for beam steering are currently being introduced or refined, such as those based on liquid crystal spatial light modulators; however, drawbacks inherent to some of these approaches include narrow field of regard, low speed operation, and low optical efficiency. An attractive method that we explore is based on optical phased arrays, which has the potential to overcome the aforementioned issues associated with other mechanical and nonmechanical beam steering techniques. The optical array phase locks a number of coherent optical emitters in addition to applying arbitrary phase profiles across the array, thereby synthesizing beam shapes that can be steered and utilized for a diverse range of applications.
Trajectory predictions of lane changing vehicles using SVM

In this paper, we present Support Vector Machine (SVM) based prediction of the trajectory of a lane changing vehicle. SVM is used for both short–range and long–range trajectory prediction of lane changing vehicles. A lane change manoeuvre is potentially dangerous and erroneous estimation may cause a collision. The necessity of forewarning drivers of the feasibility of a safe lane change requires forecast of vehicle trajectories. For this, trajectories of vehicles involved in the lane change are modelled as discrete time series using actual field data. Results indicate that SVM is able to forecast the lane change trajectory with sufficient accuracy.
Approaches for dynamic modelling of flexible manipulator systems

An investigation into the dynamic modelling of flexible manipulator systems with different mechanical structures and actuation mechanisms is presented. Dynamic models of the systems are developed based on the assumed modes method considering linear displacements, quadratic displacements and the finite element method. Simulation and experimental exercises are performed with bang-bang torque and smooth displacement driven manoeuvres. To investigate the effects of centrifugal forces, slow and fast trajectories are implemented. Simulation and experimental results of the response of the flexible manipulators are presented in the time and frequency domains. Moreover, model validations are carried out by comparing the results to assess the performance of the modelling approaches.
Creation of an Expanded Barell Matrix to Identify Traumatic Brain Injuries of U.S. Military Members

This paper describes the creation of a new traumatic brain injury (TBI) classification system, the Barell+ system, derived by the Center for Army Medical Department Strategic Studies. The Barell+ system is an expansion of the standard international Barell body region by nature of injury diagnosis matrix developed by the International Collaborative Effort on Injury Statistics. The expanded version (Barell+) was created as a result of a mapping effort between the original Barell matrix and the Department of Defense severity classification system used for surveillance by the Defense and Veterans Brain Injury Center (DVBIC). Starting with the Barell TBI category definitions, 19 additional TBI-related diagnosis codes from the DVBIC classification were mapped into the resulting Barell+ matrix. The new Barell+ system is compared with the original Barell matrix and the DVBIC classification system. We recommend using the TBI frequency distributions created by the Barell+ system as input data in U.S. military medical modeling and simulation efforts because it better reflects the actual distribution of TBI injuries.
Eggshell Crack Detection based on Acoustic Resonance Frequency Analysis

Abstract The human, visual inspection is the main quality control procedure in egg grading. Eggshells are inspected for cracks and dirtiness on the shell and for internal egg abnormalities, such as blood and meatspots. With the development of high-speed electronic grading machines (>10 000 eggs/h per lane), this human candling operation has become a significant bottleneck. Recent research into the automation of the detection of eggshell cracks is focused both on optical and mechanical detection principles. In this research, eggshell crack detection is based on the analysis of the acoustically measured frequency response of an egg excited with a light mechanical impact on different locations on the eggshell equator. The optimal configuration of the egg support, the location and design of the impactor and the response sensor are explored by means of an experimental modal analysis study of an intact egg. An egg with an intact eggshell responds by a characteristic frequency pattern that is highly repetitive when impacting on different places around the equator; the response signals of cracked eggs are heterogeneous and not repetitive. This method allows a crack detection level of 90% and a false reject level of less than 0·5%.
Nonlinear Distortion Suppression in Directly Modulated Distributed Feedback Lasers by Sidemode Optical Injection Locking

We demonstrate a new nonlinearity reduction method in directly modulated distributed feedback (DFB) semiconductor lasers. By injecting external light into a DFB laser sidemode, the nonlinear distortion of the laser is significantly reduced. Compared to the previously reported main-mode optical injection locking scheme, greater distortion suppression and a wider stable locking range can be achieved.
Simple method for a K‐band SIW filter with dual‐mode quasi‐elliptic function response

A simple method for a K‐band substrate integrated waveguide (SIW) filter with dual‐mode response quasi‐elliptic function response is designed, fabricated, and measured around 20 GHz. By using an orthogonal input and output (I/O) feed‐line and adjusting a perturbation, the proposed filter with two transmission‐zeros are so close to the passband that the selectivity and out‐of‐band rejection of the filter are significantly increased. The designed filter demonstrates the superior passband characteristics with a measured central frequency fo = 20 GHz, the insertion loss S21 = −2.9 dB, the return loss S11 = −23.5 dB. Experimental results of the fabricated filter measured by network analyzer are well agreed with the simulation results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1246–1249, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22465
Analysis of guided polarization modes in multimode rib waveguide by finite difference method

The multimode devices, which are also polarization-sensitive, have been widely used in modern optical communication system. In some cases, the modal properties, including the modal propagation constants and the modal fields of every order, must be given for the device design. The scalar finite difference beam propagation method (FD-BPM) is extended to solve this polarization-related problem. The different finite difference schemes corresponding to different polarized directions, which satisfy different boundary continual conditions, are formulized and the alternate directions implicit (ADI) FD-BPM were used to deal with the three dimensional (3D) waveguide. The guided modal properties of a 3D rib waveguide including the propagation constants and modal field distributions up to ten ranks were obtained and illustrated as an example.
Sequential localization of a radiating source by Doppler-shifted frequency measurements

For a single omnidirectional sensor in contact with a constant velocity source that radiates a constant frequency tone, the measurements of the Doppler-shifted frequencies over time do not provide sufficient information to localize the source. Instead, only the parameters of source rest frequency, speed, and range relative to a sensor can be determined. However, if over time three or more sensors sequentially come in contact with the source, the source trajectory can then be specified. This is termed sequential localization. A two-dimensional grid search technique to find the Doppler parameters from measurements taken by a single sensor alone is presented. From these parameters, it is next shown how sequential localization is accomplished. Two simulation examples are provided to verify the development. The localization root mean squared errors (RMSEs) are found to be very close to the Cramer-Rao bound. >
The Effect of Thermo-Hydrodynamics on Manual Automotive Transmissions Gear Rattle

Manual transmission gear rattle is the result of repetitive impacts of gear meshing teeth within their backlash. This NVH phenomenon is a major industrial concern and can occur under various loaded or unloaded conditions. It fundamentally differs from other transient NVH phenomena, such as clonk or thud, which are due to impulsive actions. However, they all have their lowest common denominator in the action of contact/impact forces through lubricated contacts. Various forms of rattle have, therefore, been defined: idle rattle, drive rattle, creep rattle and over-run rattle. This paper presents a dynamic transmission model for creep rattle conditions (engaged gear at low engine RPM). The model takes into account the lubricated impact force between a gear teeth pair during a meshing cycle as well as the friction between their flanks. Hertzian contact conditions are applied to the gear pair along the torque path. Additionally, isoviscous hydrodynamic regime of lubrication is assumed for unselected (loose gear pairs) with lightly loaded impact conditions. The highly non-linear impacts induce a range of system response frequencies. These include engine order harmonics, harmonics of meshing frequency and natural frequencies related to contact stiffness. The last of these are dependent on the contact geometry and lubricant rheology. The analysis includes lubricant viscosity variation due to generated contact pressures as well as temperature. For loose gears, subject to oscillations on their retaining bearings, bearing friction is also considered.Copyright © 2009 by ASME
Recoverable Private Key Scheme for Consortium Blockchain Based on Verifiable Secret Sharing

As a current popular technology, the blockchain has a serious issue: the private key cannot be retrieved due to force majeure. Since the outcome of the blockchain-based Bitcoin, there have been many occurrences of the users who lost or forgot their private keys and could not retrieve their token wallets, and it may cause the permanent loss of their corresponding blockchain accounts, resulting in irreparable losses for the users. We propose a recoverable private key scheme for consortium blockchain based on the verifiable secret sharing which can enable the user's private key in the consortium blockchain to be securely recovered through a verifiable secret sharing method. In our secret sharing scheme, users use the biometric keys to encrypt shares, and the preset committer peers in the consortium blockchain act as the participants to store the users' private key shares. Due to the particularity of the biometric key, only the user can complete the correct secret recovery. Our comparisons with the existing mnemonic systems or the multi-signature schemes have shown that our scheme can allow users to recover their private keys without storing the passwords accurately. Hence, our scheme can improve the account security and recoverability of the data-sharing systems across physical and virtual platforms that use blockchain technology.
Analysis and Design of Single Phase AC-DC Modified SEPIC Converter

Power electronic devices with front-end rectifier are widely used in industry, commerce and transportation, which result in low power factor. Though there are several proposed solutions to this, Single Ended Primary Inductance Converter (SEPIC) converter was the most successful one. But the conventional SEPIC converters suffer from high switching losses. Hence in this paper, a modified SEPIC converter is used to improve the power factor at the mains side. This paper presents the simulation and analysis of single phase single-switch, converter topologies of AC-DC SEPIC converter and modified SEPIC converter for Continuous Conduction Mode (CCM) of operation with 48V, 100W output power. The results of SEPIC converter and modified SEPIC converter are compared for closed loop analysis in simulation which is done in PSIM. It is found that modified SEPIC converter has high regulated output voltage and high power factor.
Frequency stabilisation of semiconductor lasers for heterodyne-type optical communication systems

In the somewhat distant future, heterodyne-type optical communications will appear, increasing channel capacity and repeater separation. At present, the greatest difficulty is the frequency drift of lasers. The letter describes an a.f. c. (automatic frequency control) experiment using a Peltier cooling element; it is shown that the frequency fluctuation can be reduced to below 10 MHz.
Artificial neural network based on SQUIDs: demonstration of network training and operation

We propose a scheme for the realization of artificial neural networks based on superconducting quantum interference devices (SQUIDs). In order to demonstrate the operation of this scheme we designed and successfully tested a small network that implements an XOR gate and is trained by means of examples. The proposed scheme can be particularly convenient as support for superconducting applications such as detectors for astrophysics, high energy experiments, medicine imaging and so on.
Robust control of vehicle electrorheological suspension subject to measurement noises

In this paper, a novel robust control approach is presented for a semi-active suspension with electrorheological (ER) dampers considering suspension parameter uncertainties, control input constraint, and measurement noises. By representing the suspension with parameter uncertainties in a polytopic form, applying a norm-bounded approach to handle control input constraint, and constructing an appropriate observer to estimate state variables from noisy measurements, the design of this controller is realised by solving a finite number of linear matrix inequalities with optimised performance on ride comfort and estimation error. Numerical simulations on a quarter-car suspension with an ER damper are performed to validate the effectiveness of the proposed approach. The obtained results show that the designed controller can achieve good suspension performance despite the presence of measurement noises and the variations on sprung mass and ER damper time constant with constrained control input.
Implementation of a Peatland-Specific Water Budget Algorithm in HYDROTEL

HYDROTEL, a distributed hydrological model, was used to simulate streamflows of the Necopastic watershed (N53°40.6’; W78°09.8’), James Bay, Quebec. Because of the prevalence of peatlands in the studied environment, important issues regarding soil parameterization in the vertical, three-layer, water budget sub-model (BV3C) of HYDROTEL were raised. Since BV3C was originally developed for mineral soils, an alternative, peatland-specific, water budget sub-model (PHIM) was integrated into HYDROTEL. Basic data requirements included a description of the organic soil structure and a water-table/discharge relationship. PHIM was calibrated with data collected on a peatland complex located within the Necopastic watershed. Preliminary results of observed and simulated streamflows using both the original and the adapted versions of HYDROTEL compared well, therefore leading the way to future simulations of North-Boreal watersheds.
Bridges for calibrating four-terminal-pair standards of self-inductance at frequencies up to 10 kHz

Two bridges for calibrating four-terminal-pair (4TP) standards of self-inductance in the frequency range from 500 Hz to 10 kHz are described. The first is a multifrequency double-balance bridge for linking inductance to capacitance and the second one is a modified Maxwell–Wien bridge, in which inductive voltage dividers in conjunction with fixed resistance and capacitance standards are used as balance controls. Precision voltage followers serving as unity-gain isolators assure that negligible currents are drawn from high potential terminals of 4TP bridge elements. When a procedure based on the interchange of the followers is applied, the effect of their gain errors is minimized and, for example, the value of a 100 mH inductor can then be measured with an uncertainty (k = 2) less than 2 µH at 1 kHz.
A novel reconfigurable circular polarization patch antenna

A novel design of a microstrip patch antenna with switchable branches is proposed to achieve circular polarization diversity. Two branches are incorporated into the patch and two switches are utilized to switch the branches on and off. By turning the switches on or off, this antenna can radiate with either right‐handed circular polarization or left‐handed circular polarization using the same feeding probe. Experimental results validate this concept. This design demonstrates useful features for wireless communication applications and future planetary missions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1921–1923, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23537