Miracle-dz/UniFAR-FTUs huggingface dataset:
A novel bio-based epoxy resin from oligomer: Excellent processability, high heat resistance, and intrinsic flame retardancy

Preparing an epoxy resin with biomass resources as an alternative for bisphenol A is significant for sustainable and renewable development under great pressure of limited fossil resources and urgent environmental issues. Herein, we synthesized an epoxy oligomer P-DBP-EP-n derived from biomass magnolol through an efficient one-step glycidylation. P-DBP-EP-n exhibited a low viscosity of 11.7 Pa·s at room temperature, endowing it with excellent processability as digly-cidyl ether of bisphenol A (DGEBA) and magnolol-based epoxy monomer EDBP. Then P-DBP-EP-n was cured with a diamine curing agent, 4,4′-diaminodiphenyl methane (DDM), and following thermal addition polymerization of allyl units. Compared with DGEBA/DDM and EDBP/DDM, P-DBP-EP-n/DDM possessed a higher glass transition temperature ( T g ) (304 to 167 and 226°C), implying distinguished heat resistance. Furthermore, the tensile properties and notched impacted strength of P-DBP-EP-n/DDM were better than EDBP/DDM (20.7 to 19.4 MPa, 2.0 to 1.6 GPa, and 2.5 to 2.0 kJ/m 2 ). The initial degradation temperature and char residue of P-DBP-EP-n/DDM were 421°C and 35.2%, with a 13.5 and 101% increase compared with those of DGEBA/DDM, respectively. Additionally, P-DBP-EP-n/DDM displayed outstanding flame retardancy with V-0 rate for the vertical burning test and limiting oxygen index value of 47.7%, which was almost twice as much as that of DGEBA/DDM. This study offers a promising and feasible pathway to obtain a fully bio-based epoxy resin substituted for petroleum-based DGEBA with distinguished processability, heat resistance, and flame retardancy. Comprehensive properties of the bio-based thermosets are expected to be further regulated by the thermal addition polymerization of allyl units.
Anisotropic Parameter Modeling based on Deep Residual Network

With the improvement of underground imaging precision, anisotropic media imaging has gradually become a conventional method. Anisotropic parameter modeling provides the final model for subsequent migration imaging and has an important influence on the quality of migration imaging. Therefore, it is necessary to study the anisotropic parameter modeling technology with high precision. As a method of constructing velocity model, tomography has become a common processing tool. However, there are also difficulties in conventional reflection tomography: (1) Travel time difference is difficult to obtain, especially for pre-stack data with low SNR; (2) During ray tracing, a large number of interpolation and test firing are required to fit the coordinates of the shot-receiver point, and there are complex reflection problems (Woodward 2008).
Augmented Nonlinear Least Squares Estimation With Applications to Localization

Least squares (LS) estimation is simple yet effective for parameter estimation. Most real-world problems are nonlinear. In practice, nonlinear LS problems are linearized first and then solved by a linear LS estimator. However, since these methods solve a nonlinear LS problem by a linear way, there is room for improvement only if estimators being nonlinear in the original measurement. In this article, an LS approach is proposed for nonlinear LS problems, along with theoretical analysis and justification. First, for a general nonlinear measurement model with any form of noise, a unified linearization (UL) approach is proposed under certain assumptions and a linearized least squares (LLS) estimator is defined based on the UL model. Second, an augmented nonlinear least squares (ANLS) estimator is proposed based on LLS estimation. In the ANLS estimator, the original measurement is augmented by its nonlinear conversion intended to further utilize the nonlinear measurement. Moreover, we prove that the ANLS estimator outperforms LLS estimation-based estimators. Finally, the UL and the ANLS estimator are applied to source localization with time difference of arrival and/or frequency difference of arrival measurement, and a two-step ANLS localization algorithm is developed. The performance of the proposed algorithm is evaluated via simulation of some typical localization scenarios.
INTEGRATED MULTI BEAM SPECTROSCOPY WITH EMBEDDED PRECISE OPTICS

This paper reports the integrated dual beam photothermal spectroscopic device with embedded precise conventional optics. We have integrated lithography lenses, a fluidic channel and embedded precise conventional prisms. The embedded prisms were utilized for input or output ports of the excitation and probe beams. In the chip, the beams were focused by the lithography lens and crossed at a controlled angle in the fluidic channel. Performance of the device was tested by calibrating dye solutions.
A wideband ultrathin low profile metamaterial microwave absorber

A novel design of wideband ultrathin, low profile metamaterial microwave absorber has been presented. The structure is composed of a periodic array of microstrip bend, like structure printed on metal backed FR4 dielectric substrate. The 10 dB absorption bandwidth from 8.60 to 12.35 GHz covering X‐band has been observed in simulation for normal incidence. The FWHM bandwidth of 5.72 GHz has been observed ranging from 8.07 to 13.79 GHz. The proposed design is low profile (unit cell size 0.16 λ0) and is ultrathin (λ0/18 thick at center frequency of 10.47 GHz). The designed absorber is fabricated and experimentally verified for normal and oblique incidence angles. The performance of the proposed absorber at different angles of polarization has also been investigated. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2723–2728, 2015
Automatic Tuning Method for PMSM using Big Data based Artificial Neural Network

Methods based on linear analysis have been studied for stable control of permanent magnet synchronous motors; however, they are difficult to apply in the operating regions and under control conditions that cannot be linearized. In such instances, trial and error tuning is required to obtain the desired characteristics. In this study, we investigate a method of learning for an artificial neural network using a large amount of adjusted PMSM parameter data and derive the control parameters to stably drive the PMSM.
Analytical maps of aerodynamic damping as a function of operating condition for a compressor profile

In this paper analytical maps of aerodynamic damping for a two-dimensional compressor cascade (Standard Configuration 10) are presented. The maps are shown as contour plots of the aerodynamic damping as a function of operating condition. The aerodynamic dampings were calculated by a linearized Navier-Stokes flow solver The flutter boundaries over a wide range of operating conditions are clearly shown on the damping maps and were found to be strongly dependent on the mode frequency and the mode shape. Extremely low values of negative aerodynamic damping were predicted for some off-design operating conditions where flow separation occurred. A damping map was also constructed based on inviscid flow simulations. There were differences in the viscous and inviscid flutter boundaries particularly at off-design inflow angles. The extremely low values of negative aerodynamic damping were only predicted by the viscous simulations and not the inviscid simulations.
Reduction control of mechanical vibration of an induction motor with fluctuated torque load using repetitive controller

Authors propose a method to reduce the vibration of the V/F controlled induction motor with a fluctuated torque load by repetitive control utilizing acceleration sensor. It is easy to install the acceleration sensor on the motor or load frame. Because the load torque varies periodically, the repetitive control is considered effective for reduction of the vibration. Approximate analysis is performed to study the stability of the repetitive control system. Effectiveness of the proposed method is confirmed by experiments. <<ETX>>
APPROACHING MENTAL HEALTH: SOCIAL ECOLOGICAL MODEL AND THEORY OF PLANNED BEHAVIO

Muslims underutilize Formal Mental Health Services (FMHS) to enhance their quality of life or address their biopsychosocial spiritual and economic issues. Muslims are understudied and underserved. There is a need for theoretically well-grounded research. Therefore, we partially tested a contextual theoretical framework entitled understanding Muslims’ approach toward mental health issues and services based on Theory of Planned Behavior and Theory of Reasoned Action (TPB/TRA) in the context of Social Ecological Model (SEM). We had 209 (120 male) Muslims from Southeastern USA as the participants. We used descriptive statistical and path analyses. We answered seven research questions about how the Muslims approach mental health issues and FMHS in terms of four background variables (e.g., sex, education, race, and past use of FMHS) and the following five constructs. In terms of path analyses results, cultural beliefs about mental health issues and their causes and treatments (1 construct) and knowledge (2 construct) toward FMHS and the background variables all together explained 36% of the attitudes (3), 13% of the stigma (4), and 28% of the Perceived Behavioral Control (PBC: self-efficacy, 5) toward FMHS. The paths among the five constructs were significant except for the path from knowledge to stigma. The Muslims had slightly higher than the moderate level on cultural beliefs, knowledge, and PBC; a moderately favorable level on attitudes; and slightly under the moderate level for PBC. The Muslims did not strongly favor or disfavor the constructs. The Muslims strongly aligned with a medical/scientific explanation of mental health issues and their causes and treatments. For the use of FMHS in the past: 63.63% (133 Muslims) reported they have never while %36.36 (76 Muslims) reported use of FMHS. We provided implications for researchers, mental health providers, educators, and social advocates who can be part of advancing quality of life and/or addressing related issues.
Wetland meadows of carex acutiformis as a source of bioelectricity of agglomeration atmospheric air pollution and environmental safety of the practices

The article presents the assessment of bioelectroproductivity of wetland sedge ecosystems of Carex acutiformis in situ. It was found that it is possible to obtain a bioelectric potential at the level of 864.2-1114.8 mV, depending on external conditions using a pair of electrodes graphite/zinc-galvanized steel and graphite/aluminum. The increase in soil moisture had a positive effect on bioelectric potential parameters. Widespread in Polissya biotopes of sedge have prospects as sources of green plant-microbial energy.
Study on Protective Data Flow of Intelligent Substation Based on IEC 61850

This paper analyzes protective data flow in normal state and after failure with IEC 61850 D2-2 type substation. Focusing on the flow which conform to IEC 61850 Ethernet protocol by using Optimized Network Engineer Tools (OPNET) simulator, the protective data in D2-2 type substation is simulated based on IEEE 802.1Q priority-tag and VLAN technology. A sample Substation Automatic System (SAS) network is constructed, and the main factors affecting the delay of protective data is discussed in detail.
Structural topology optimization for the design of broadband dielectric resonator antennas using the finite difference time domain technique

Dielectric resonator antennas (DRAs) are a relatively new class of antenna that utilizes the radiation phenomena of dielectric resonators in open space. Since mainly analytical approaches have been applied to investigate DRA designs, the current DRA forms are limited to simple geometric shapes and high‐performance DRAs with complex shapes have not yet been developed. Topology optimization is capable of yielding high‐performance structures, and has been extensively applied to a variety of structural optimization problems. Applying it to the task of DRA design may be extremely useful for the design of high‐performance antennas. On the other hand, the finite difference time domain (FDTD) method has been used to numerically evaluate general antenna performance, since it is numerically robust during time domain analyses and can handle complex models. Thus, the integration of topology optimization with the FDTD method has the potential to enable innovative designs of advanced antennas that offer exceptional performance. In this research, we propose a new topology optimization method for the design of DRAs that aim to operate with enhanced bandwidths, using the FDTD method. First, the concept of topology optimization is briefly discussed, and a way to integrate topology optimization with the FDTD method is proposed. Next, design requirements are clarified and the corresponding objective functions and the optimization problem are formulated. An optimization algorithm is constructed based on these formulations. Finally, several DRA design examples are presented to confirm the usefulness of the proposed method. Copyright © 2007 John Wiley & Sons, Ltd.
Improving a current method for predicting walking-induced floor vibration

Serviceability rather than strength is the most critical design requirement for vibration-vulnerable floor constructions. Annoying vibrations due to normal walking activity have been observed more frequently on long-span lightweight floor systems in office and commercial retail buildings, raising the need for the development of floor vibration design procedures. This paper highlights some limitations of one of the most commonly used guidelines AISC/CISC DG11, and proposes improvements to this method. Design charts and approximate closed form formulas to estimate the walking response are developed in which various factors relating to the dynamic characteristics of both the floor and the excitation are considered. The accuracy of the proposed formulas and other proposals found in the literature is examined. The proposed modifications would be significant, especially with long-span floors where vibration levels may be underestimated by the current design procedure. The application of the proposed prediction method is illustrated by worked examples that reveal a good agreement with results obtained from finite element analyses and experiments. The presented work would enhance the accuracy and maintain the simplicity and convenience of the design guideline.
A Confirmatory Factor Analysis of Two Web Site Usability Instruments

Many perspectives of user acceptance of Web sites have been examined, yet information systems research often overlooks the human-computer interaction aspects, particularly in the area of Web site usability. Web site usability has recently gained greater acceptance in information literature through the development of instruments by Palmer (2002) and Agarwal and Venkatesh (2002). This study conducted a confirmatory factor analysis of both instruments in an attempt to validate the two instruments. Our results found that the Palmer instrument exhibited satisfactory measurement properties, although allowing room for further refinement. The Agarwal and Venkatesh instrument, although useful as a practical metric, displayed poor validity for the underlying constructs that compose Web site usability. Validation of these instruments furthers their scope and potential use by researchers and practitioners in helping them better understand the capabilities of their Web sites, while providing a foundation for further refinement of the Web site usability construct.
Learning Users Inner Thoughts and Emotion Changes for Social Media Based Suicide Risk Detection

Suicide has become a serious problem, hurting the well-being of human society. Thanks to social media, from people's linguistic posts, suicide risk detection has achieved good performance. The aim of this article is to investigate whether more significant accuracy could be achieved. Motivated by the observation that the prior solutions strived to detect suicide risk based on users explicit outer post expressions on social media, and no attempt was made to infer users’ inner true thoughts and emotion changes from their normal open posts for suicide risk detection, we propose to first learn the correlations between user's normal open posts and hidden comments, trying to understand user's inner true thoughts and emotion changes from the open posts, and then detect user's suicide risk upon the generated intermediate results. The better detection performance on the microblog dataset (3,652 at-risk microblog users and 3,652 ordinary microblog users) and forum dataset (392 at-risk forum users and 108 ordinary forum users) verifies the insight that it is more effective to learn users’ inner thoughts and emotion changes for social media-based suicide risk detection.
Validation of a Numerical Method for Extracting Liner Impedance

We report the initial results of a test series to evaluate a method for extracting the normal-incidence impedance of a locally reacting liner located in a grazing incidence environment. This initial evaluation tests the method''s ability to converge to the known impedance of a solid steel plate, and to the impedance of an absorbing test specimen whose impedance was measured in a normal incidence impedance tube. The method converges to the measured normal-incidence impedance values and thus is an adequate tool for extracting the impedance of specimens in a grazing-incidence, multimodal, nonprogressive acoustic wave environment for a broad range of source frequencies.
Realization of loss-free resistive elements

The realization of loss-free elements with resistive I-V characteristics is presented. The realization is achieved by controlling the parameters of loss-free two-ports that have a transformer or gyrator matrix. The power absorbed by the element is transferred to the source, so that, in principle, no losses occur. The use of such elements is expected to be of importance in power electronics, power conversion systems, gas discharge devices, control systems, robotics, and microwave circuits. Such an element was realized using a switched-mode circuit technique. It was applied to the stabilization of a gas laser system. The circuit replaced a conventional resistor that dissipated power up to 40 W. The replacement circuit dissipated only 10 W (equivalent to a conversion efficiency of 75%). >
Multilevel inverter topology based on series connected switched sources

A new topology for multilevel DC–AC conversion is presented in this study. It consists of isolated symmetric input DC sources alternately connected in opposite polarities through power switches. The structure allows synthesis of multilevel waveform using reduced number of power switches as compared to the classical topologies. The working principle of the proposed topology is explained with the help of a single-phase five-level inverter. Simulation studies are carried out in MATLAB/Simulink environment and experimental validations are obtained on a laboratory prototype. An exhaustive comparison of the proposed topology against the classical cascaded H-bridge topology indicates reduction in number of power switches, losses, installation area and converter cost.
Discrimination and clustering of earthquakes and explosions based on NDWT

ABSTRACT This article is concerned with the development of discrimination procedure for seismic data based on feature extraction. These features are the maximum and minimum (maximin) values of Nondecimated Wavelets Transform (NDWT), which were extracted from the P component of the original earthquake and explosion traces. The method provides small error rates in both discrimination and clustering seismic wave datasets. It has been shown that our procedure performs as well as other procedures and in some cases better than other classifications methods. Also, the performance of our procedure is evaluated via a simulation study.
Robust algorithmic detection of the developed cardiac pathologies and emerging or transient abnormalities from short periods of RR data

Numerous research efforts and clinical testing have confirmed validity of heart rate variability (HRV) analysis as one of the cardiac diagnostics modalities. The majority of HRV analysis tools currently used in practice are based on linear indicators. Methods from nonlinear dynamics (NLD) provide more natural modeling framework for adaptive biological systems with multiple feedback loops. Compared to linear indicators, many NLD‐based measures are much less sensitive to data artifacts and non‐stationarity. However, majority of NLD measures require long time series for stable calculation. Similar restrictions also apply for linear indicators. Such requirements could drastically limit practical usability of HRV analysis in many applications, including express diagnostics, early indication of subtle directional changes during personalization of medical treatment, and robust detection of emerging or transient abnormalities. Recently we have illustrated that these challenges could be overcome by using classific.
Hardened Layer and Bending Fatigue Strength of Induction Hardened Thermally Refined Steel Gears

This paper presents a study on effects of the pre-treatment and the heating time on the hardened layer and the bending fatigue strength of induction hardened gears. The measurement of hardened layer and the bending fatigue test of induction hardened gears made of thermally refined and as-rolled S35C and S45C steels were carried out, and then profiles of hardened layer and S-N curves were obtained. Effects of the pre-treatment and the heating time on profiles and micro structures of hardened layers of induction hardened gears were examined. The relationship between the bending fatigue strength and the profile of hardened layer was determined. An optimum heating condition for the bending fatigue strength of induction hardened S35C and S45C steel gears were indicated.
Cognitive AmBC-NOMA IoV-MTS Networks With IQI: Reliability and Security Analysis

Internet-of-Vehicle (IoV) enabled Maritime Transportation Systems (MTS) communication is anticipated to support ultra-reliable and low latency, diverse quality-of-service (QoS) and large-scale connectivities. To meet such stringent demands, a cognitive ambient backscatter non-orthogonal multiple access (C-AmBC-NOMA) IoV-MTS network is proposed. We explore the reliable and secure performance of the proposed C-AmBC-NOMA IoV-MTS network with in-phase and quadrature phase imbalance (IQI) at radio-frequency (RF) front-ends and the existence of an eavesdropper. In particular, the analytical expressions on the outage probability (OP) and intercept probability (IP) are obtained after a series of calculations. For a deeper understanding, we discuss the asymptotic behavior of OPs in the high signal-to-noise ratio (SNR) region, the diversity orders of OPs, and IPs in the high main-to-eavesdropper ratio (MER) regime. The results of Monte-Carlo simulation and a series of corresponding theoretical analysis show that: i) As the SNR approaches infinity, the OPs tend to be fixed non-negative values, indicating that the diversity orders of the OPs have error floors; ii) When the MER approaches infinity, the IPs of legitimate users decrease continuously, while the IP of backscatter device (BD) increases; iii) Compared with the system performance under ideal condition, the system performance is less reliable under IQI condition, but the security performance is enhanced; iv) By carefully selecting the system parameters, a trade-off can be achieved between reliability and security.