Miracle-dz/UniFAR-FTUs huggingface dataset:
Wave Propagation in Electromechanical Structures: Induced by Surface-Bonded Piezoelectric Actuators

Surface-bonded piezoelectric actuators can be used to generate Rayleigh wave for monitoring surface damages of structures. This paper provides an analytical and numerical study to simulate the wave propagation in an elastic half plane with surface-bonded piezoceramic actuators under high-frequency electric loads. Based on a one dimensional actuator model, the wave propagation induced by a single actuator is studied first by using integral transform method and solving the resulting integral equations. The single actuator solution is then implemented into a Pseudo-incident wave method to study the wave propagation induced by multiple actuators. Two aspects of the work are examined. The first is concerned with the determination of the effect of the geometry, the material mismatch and the loading frequency upon the resulting waveform, while the second is concerned with the effect of the interaction between actuators upon the induced wave propagation.
Vibration Characteristics of Stiffened Plates

This paper describes methods of calculating natural frequencies of free flexural vibration of rectangular plates which have stiffeners parallel to one edge.An approximate frequency equation is derived for a clamped plate with closely spaced stiffeners by extending the Rayleigh method as applied by Warburton (1)† to rectangular isotropic plates. For a plate containing a single central stiffener, an exact frequency equation is derived for simply supported edges and an approximate fundamental frequency equation is derived for clamped edges. Comparison between observed and calculated frequencies is made and the practical effect of stiffening upon natural frequencies is discussed. The application of the Rayleigh method to the calculation of natural frequencies of integrally stiffened plates is illustrated by calculating frequencies determined by Hoppmann and Thorkildsen (2).
Head injury criterion: the best way to evaluate head damage?

During the design and construction of a new car model, there are a lot of important aspects that have to be taken into account. The car's designers look for a beautiful appearance, for a car as light as possible, try to reduce the manufacture costs and times and, of course, want to guarantee that their car is as safe as it can be. There are several criteria that allow to quantify the safety of a car. One of them, the Head Injury Criterion (also known as HIC) gives a measure of the damage that the head can suffer in case of collision. This paper presents a review of some works related to this criterion. It will be proved that the HIC has several limitations that allow to say that this criterion is clearly improvable.
Methods and Limitations of Line Source Simulation

Although line array systems are in widespread use today, investigations of the requirements and methods for accurate modeling of line sources are scarce. In previous publications the concept of the generic loudspeaker library (GLL) was introduced. It is shown that on the basis of directional elementary sources with complex directivity data finite line sources can be simulated in a simple, general, and precise manner. Measurement requirements are derived, and the limitations of this model are discussed. In addition, a second step of refinement is presented, namely, the use of different directivity data for cabinets of identical type based on their positions in the array. All models are validated by measurements. The approach presented is compared with other proposed solutions.
Test Research on Influence of Water and Mineral Composition on Physical and Mechanical Properties of Phyllite

As a regional metamorphic rock, the engineering properties of the phyllite are rather complex. It is common that the tunnel construction safety has tremendous difficulty due to the groundwater, the initial stress state, joints, cracks and faults and other factors, so it is necessary to find an effective construction method for the construction of phyllite tunnel. To master the regular pattern of the influence of relative factors on physical and mechanical properties of phyllite is the basis to establish an effective construction method. The paper tries to analyze the influence of water and mineral composition on physical and mechanical properties of phyllite by making relevant tests on Lu Lin tunnel, and hope to give some clue to the design and construction of phyllite tunnels.
Optimum planting date for the maximum tuber yield of tropical sugar beet (Beta vulgaris L.) genotypes in the Old Brahmaputra Floodplain

Planting dates for a crop is a non-monetary input but plays a significant role in increasing the yield crop. Therefore, identifying genotype-specific planting dates is essential for obtaining the economic yield of tropical sugar beet. From this perspective, a field experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University in Bangladesh, from November 2015 to April 2016. Five sugar beet genotypes: Shubhra, Cauvery, EB-0616, EB-0626, and EB-0809 planted on four dates: 10, 20, 30 November, and 10 December. Treatments were laid out in a split-plot design replicated three times. Data revealed that planting on 10 November date, genotype EB-0809 produced the highest tuber yield, which was significantly superior to any other genotype combined with other planting dates. It was found that every ten days delay of planting from 10 November to 30 December reduced the tuber yield by 30, 43, and 55%, respectively. Results confirmed that planting the EB-0809 genotype on 10 November is ideal to obtain the highest tuber yield of tropical sugar beet in Bangladesh.
Nondestructive Crack Detection Algorithm for Full-Scale Bridges

A nondestructive crack detection (NCD) scheme to locate a crack and estimate the crack size by using changes in the modal parameters of a class of bridges is presented in this paper. First, the theory underlying a nondestructive crack localization and crack-size estimation algorithm for beam-type structures is outlined. Next, a field experiment to verify the feasibility and applicability of the NCD scheme is detailed. In that experiment, predamage and postdamage modal data extracted from a full-scale plate–girder bridge are described. The modal data are fed into the NCD scheme that localizes crack and estimates crack size in the test structure. The result of the analysis indicates that the proposed NCD algorithm correctly locates the crack and accurately estimates the size of the crack.
Ground Motion Selection for Liquefaction Evaluation Analysis of Earthen Levees

Guidelines for selecting ground motions for liquefaction evaluation analysis of earthen levees are proposed. These guidelines were developed based on results from dynamic analyses of characteristic earthen levee cross sections using a wide range of ground motions (~1,500). The effect of a number of ground motion parameters on the dynamic response of the levees in terms of liquefaction susceptibility was studied, and the parameters that correlated best to the response were identified. For the liquefaction triggering evaluation, the mean period of the ground motion (Tm) is best correlated to the cyclic stress ratio (CSR). Regression relationships between CSR and Tm are proposed for a series of levee types and shaking intensities.
Quantification methods of technical building performance

A building performance assessment toolkit was developed for use by large corporate owners and building portfolio managers in the US. A variety of technical performance aspects are addressed such as energy, lighting, thermal comfort, maintenance and indoor air quality. Every assessment is based on a normative and objective Performance Indicator (PI). For easy data capture and calculation of PIs, the toolkit was implemented in a web hosted form, enabling facility managers and staff to collect the data during a walk-through enabled by PDA-based data entry. The current set of performance indicators is discussed and the results of the first benchmarks, most notably the energy benchmarks, are reported.
2.4 GHz Class-E power amplifier with transmission-line harmonic terminations

The design procedure, fabrication and measurement of a Class-E power amplifier with excellent second- and third-harmonic suppression levels are presented. A simplified design technique offering compact physical layout is proposed. With a 1.2 mm gate-width GaAs MESFET as a switching device, the amplifier is capable of delivering 19.2 dBm output power at 2.41 GHz, achieves peak PAE of 60% and drain efficiency of 69%, and exhibits 9 dB power gain when operated from a 3 V DC supply voltage. When compared to the classical Class-E two-harmonic termination amplifier, the Class-E amplifier employing three-harmonic terminations has more than 10% higher drain efficiency and 23 dB better third-harmonic suppression level. Experimental results are presented and good agreement with simulation is obtained. Further, to verify the practical implementation in communication systems, the Bluetooth-standard GFSK modulated signal is applied to both two- and three-harmonic amplifiers. The measured RMS FSK deviation error and RMS magnitude error were, for the three-harmonic case, 1.01 kHz and 0.122%, respectively, and, for the two-harmonic case, 1.09 kHz and 0.133%.
Purchasing performance management systems: an empirical investigation

This article aims at further developing the purchasing performance management systems (PPMSs) body of knowledge, assuming the wider perspective of the adoption process rather than key performance indicators (KPIs) only. In particular, the research questions are focused on understanding what are the most adopted indicators, what are the key elements characterising the implementation process and what are the differences among different organisational levels and different purchasing categories. The literature provides a framework for classifying purchasing KPIs, identifying the implementation process and the PPMS architecture, thus supporting the empirical research protocol. Nine case studies of large multinationals belonging to different industries are conducted. Empirical evidence shows that companies are still adopting mainly an external perspective, by focusing on performance measurement efforts on suppliers. Widely adopted indicators mainly measure cost, time and quality. However, the purchasing department has acquired an important role within the organisation and new performance indicators have been created; flexibility, innovation and sustainability are becoming increasingly important.
Racial discrimination towards Asian operatives in the Australian construction industry

This paper investigates racial discrimination towards Asian operatives in the Australian construction industry. It explores the extent of this discrimination, the form it is taking, the impact it is having and how it is being managed. The paper reveals an assimilationist culture which largely ignores the needs of ethnic minority groups and fails to harness the positive attributes of multiculturalism. Ironically, in comparison with other industries, the construction industry is relatively well placed to benefit from cultural diversity, and a number of suggestions are made to help companies achieve this. These suggestions are of value to managers in other countries because racism is not a problem that is unique to the Australian construction industry.
Suex flapping wing mechanisms for pico air vehicles

This paper introduces a simple and low cost flapping wing mechanism fabricated monolithically from SUEX dry film, an epoxy based negative photoresist similar to SU-8. The developed process has fewer steps compared to other methods, does not use precious metals, and greatly reduces processing time and cost. It simultaneously defines the PAV airframe, compliant flapping mechanism, and artificial insect wing using photolithography. Rapid prototypes were fabricated with precisely defined features and material properties and geometry that are similar to insects. A linear model with simplified aerodynamics is developed with amplitude dependent damping and validated using experimental results in air and in vacuum. Angles up to 45° at a resonant frequency of 47 Hz are observed that demonstrate applicability of the developed fabrication process for flapping wing air vehicle applications. © 2012 ASME
An algorithm to identify text marked in rock core pictures with machine learning algorithm

The aim of our project is to extract numerical descriptors or gather feature of rock samples from their images made under microscope with computer vision algorithm which can overcome the bottleneck of traditional method. It is impossible to solve it without getting the imformation of microscope magnification of images when they were made. That is why this paper is about an algorithm to identify the text used to mark microscope magnification information in rock core sample pictures. This is a sub project. As locations of text in these pictures are not fixed, font of text is not fixed, font size of text is not fixed, a method of two steps is designed to identify the text from the background. It works as follows: first, find the location of text; second, recognize the text with Convolution Neural Network. Experimental results demonstrate the potential value of the proposed approach to identify the magnification information in rock core sample pictures and to apply as a funtion to a program of our future project.
Dynamic Stability of the Peace River Transmission System

The transient and dynamic stability of the Peace River 500-kV transmission system was studied with a new digital computer program. The detailed representation included direct and quadrature machine axes, saturation, excitation, and governing systems. Stability is maintained following faults by employing a braking resistor and additional stabilizing signal to the generator excitation system.
Spectral feature extraction and modeling of soil total nitrogen content based on NIR technology and wavelet packet analysis

It is a non-destructive and real-time method to detect the soil nutrient content by using spectroscopy analysis technology. In order to isolate the effective spectral for TN content from the soil spectra effectively, the NIR model predicting TN was developed based on wavelet packet analysis. 100 soil samples were collected for calibration and validation from the field. First, using the high-precision NIR detecting instrument to scan the target and obtaining the continuous spectra of soil samples in the laboratory. Secondly, with three different orthogonal wavelets (bior4.4, db4, sym4) as the generating functions, the original signal of each soil sample was decomposed and reconstructed based on the respective wavelet packet. Then the multiple linear regression (MLR) models for TN were established based on each drawn characteristic spectrum. Finally, three models were compared and analyzed, and the model with the highest forecasting accuracy was obtained based on db4, which determined R2 reached 0.904. The research concluded that wavelet packet analysis could eliminate or substantially reduce the factors outside the parameters to the spectrum directly or indirectly, and the obstacles in establishing linear models for soil parameters were removed. It is feasible and potential to the real-time prediction of TN content.
The influence of blade lean on turbine losses

Three linear cascades of highly loaded, low aspect ratio turbine blades have been tested in order to investigate the mechanisms by which blade lean (dihedral) influences loss generation. The blades in all three cascades have the same section but they are stacked perpendicular to the endwall in the first cascade, on a straight line inclined at 20° from perpendicular in the second and on a circular arc inclined at 30° from perpendicular at each end in the third cascade.Lean has a marked effect upon blade loading, on the distribution of loss generation and on the state of boundary layers on the blade suction surfaces and the endwalls, but its effect upon overall loss coefficient was found to be minimal. It was found, however, that compound lean reduced the downstream mixing losses, and reasons for this are proposed. Compound lean also has the beneficial effect of substantially reducing spanwise variations of mean exit flow angle. In a turbine this would be likely to reduce losses in the downstream bladerow as well as making matching easier and improving off-design performance.Copyright © 1990 by ASME
Evaluation of the Thorax of Manduca Sexta for Flapping Wing Micro Air Vehicle Applications

In the 1990's, DARPA awarded several contracts to companies to research, design, and construct a Flapping Wing Micro Air Vehicle (FWMAV). The tobacco hornworm hawkmoth (Manduca sexta) provides an excellent model from which to gather knowledge pertaining to the development of a Flapping Wing Micro Air Vehicle (FWMAV). One of the major challenges in design of a FWMAV is the energy demanding nature of low Reynolds number flapping flight. Therefore, an understanding of the power required by the flight muscles to actuate the wings is essential for the design of a FWMAV. The M.sexta wing/thorax mechanism was evaluated as a mechanical system in order to gain insight to the mechanical power required to produce the full natural wing stroke. A unique dynamic load device was designed and constructed to mechanically actuate the upstroke and downstroke of the M.sexta in order to achieve the full flapping motion. Additionally, the forces applied through the flight muscles were directly measured in order to attain the power requirements of the flight muscles simultaneously. The experiment yielded wing stroke values of + 60 and – 35 degrees, which is what is seen in nature during hovering. The DVM and DLM muscle groups were calculated to have a power density of 112 W/kg with the vehicle energy density being 2.5 W/kg. The power output requirement indicates the need for a lightweight and energy-dense power source/actuator combination for the development of FWMAVs.
Short-Crack Growth Behaviour in an Aluminum Alloy: An AGARD Cooperative Test Programme

An AGARD Cooperative Test Program on the growth of short fatigue cracks was conducted to define the significance of the short-crack effect, to compare test results from various laboratories, and to evaluate an existing analytical crack-growth prediction model. The initiation and growth of short fatigue cracks (5 micrometer to 2 mm) from the surface of a semi-circular notch in 2024-T3 aluminum alloy sheet material were monitored under various load histories. The cracks initiated from inclusion particle clusters or voids on the notch surface and generally grew as surface cracks. Tests were conducted under several constant-amplitude (stress ratios of -2, -1, 0, and 0.5) and spectrum (FALSTAFF and Gaussian) loading conditions at 3 stress levels each. Short crack growth was recorded using a plastic-replica technique. Over 250 edge-notched specimens were fatigue tested and nearly 950 cracks monitored by 12 participants from 9 countries. Long crack-growth rate data for cracks greater than 2 mm in length were obtained over a wide range in rates (10 to the -8 to 10 to the -1 mm/cycle) for all constant-amplitude loading conditions. Long crack-growth rate data for the FALSTAFF and Gaussian load sequences were also obtained.
Design and analysis of unequal split Bagley power dividers

In this article, we propose a general design procedure to develop unequal split Bagley power dividers (BPDs). Based on the mathematical approach carried out in the insight of simple circuit and transmission line theories, exact design equations for 3-way and 5-way BPDs are derived. Utilising the developed equations leads to power dividers with the ability of offering different output power ratios through a suitable choice of the characteristic impedances of the interconnecting transmission lines. For verification purposes, a 1:2:1 3-way, 1:2:1:2:1 5-way and 1:3:1:3:1 5-way BPDs are designed and fabricated. The experimental and full-wave simulation results prove the validity of the designed unequal split BPDs.
Tumor necrosis factor α knockout impaired tumorigenesis in chronic myeloid leukemia cells partly by metabolism modification and miRNA regulation

Purpose Half of the chronic myeloid leukemia (CML) patients with sustained deep molecular response suffer from relapse after discontinuation mainly because tyrosine kinase inhibitors (TKIs) cannot eradicate leukemia stem cells (LSCs). In addition, tumor necrosis factor α (TNF-α) is highly detected in CML patients. Our aim was to explore whether TNF-α is a potential target for LSC elimination. Materials and methods We applied a CRISPR/Cas9 gene editing technique, colony-forming cell assay, subcutaneous tumor models, miRNA-seq and liquid chromatography-mass spectroscopy (LC-MS) on metabonomics to explore the feasibility and mechanism of TNF-α as a new therapeutic target for CML. Results We demonstrated that TNF-α knockout remarkably decreased the proliferative, colony-forming and in vivo tumorigenesis capacities of the CML K562 cell line. The apoptosis was increased when TNF-α knockout cells were cultured with imatinib. The mechanisms involved in the abovementioned phenomena were that TNF-α knockout inhibited the citrate cycle and increased starch, sucrose, amino sugar and nucleotide sugar metabolism. In addition, differentially expressed miRNAs between TNF-α knockout and control cells were involved in the cell cycle, CML, P13K-Akt and pathways in cancer. Conclusion We identified that TNF-α may serve as a new target therapy for CML and described the metabolic pathways associated with TNF-α in CML cells for the first time.
Experimental Investigation of Stall in a Two Stage Compressor

This paper is concerned with the experimental characterisation of the unstable behaviour exhibited by a two stage axial flow compressor with variable geometry inlet guide vanes. The characterisation includes performance assessment stall transient and determination of three dimensional flow during one cell operation. The three flow components have been measured with a single slanted hot wire ensemble phase averaging technique based on several cell passages. This technique, already successfully applied for stall in an isolated rotor, is now tried on the more complex two stage compressor.Copyright © 2000 by ASME
Towards a wearable device for skill assessment and skill acquisition of a tennis player during the first serve

In this article, the possibility of using wearable gyroscope sensors for skill assessment and skill acquisition was investigated. Marker‐based methods were used initially to capture the fast rotational motions and simulate the outputs of gyroscope sensors. Utilizing the marker‐based methods, the angular velocity of the upper arm internal rotation, wrist flexion, and shoulder rotation were calculated for a range of athletes using the trajectory of Vicon markers with respect to the Plug‐in Gait model during the first serve in tennis. Participants from amateur to elite participated in this study. Thirty successful serves from each participant were assessed. The results showed that the peak values of the upper arm internal rotation, wrist flexion, and shoulder rotation just before impact are indicative in classifying the participants’ skill level. It was shown that all the three parameters, as well as the racquet head speed, increased as the level of proficiency of the participants increased. A line (R2 = 0.89) was fitted to the scatter data containing the upper arm internal rotation, wrist flexion, and racquet head speed. The fit line is a function of upper arm rotation and wrist flexion. The fit line can be used as a potential skill acquisition tool to provide feedback on which variables (upper arm internal rotation, wrist flexion, or shoulder rotation) need to be improved. The positions of three gyroscope sensors to detect the same trends as those from the marker‐based methods were determined. Therefore, it is envisaged that gyroscope sensors could be used for skill assessment and skill acquisition for a first tennis serve.