Miracle-dz/UniFAR-FTUs huggingface dataset:
Nonlinear Static Analysis of UHV Tower with Considering Joint Slippage

In the traditional lattice tower design process, the effects of bolted joint slippage are not taken into account, which cause great discrepancy between numerical analysis and full tower tests. In this paper, several joint slippage models are presented with considering the joint connection types and number of bolts. The finite element models of UHV transmission tower are built with introduce the joint slippage effects, and then the inner force and deformation of transmission tower under strong wind load case was studied and the influence of joint slippage are discussed by using the nonlinear static analysis method.
Mill specific prediction of worsted yarn performance

Abstract Different spinning mills use different raw materials, processing methodologies, and equipment, all of which influence the quality of the yarns produced. Because of many variables, there is a difficulty in developing a universal empirical/theoretical model. This work presents a multilayer perceptron algorithm (MLP) model for the purpose of building a mill specific worsted spinning performance prediction tool. Sixteen inputs are used to predict key yarn properties and spinning performance, including number of fibers in cross-section, unevenness (U%), thin places, neps, yarn tenacity, elongation at break, thick places, and spinning ends-down. Validation of the model on mill specific commercial data set shows that the general fit to the target values is good. Importantly, the performance of the MLP shows a certain degree of stability to different, random selections of independent test data. Subsequent comparison against the predicted outputs of Sirolan Yarnspec™ confirms the overall performance of the artificial neural network (ANN) method to be more accuratefor mill specific predictions.
Wavelength diversity based infrared super-resolution and condition-based maintenance

The relevance of image sequence super-resolution (SR or high resolution (HR)) and wavelength diversity to encompass IR imaging for condition-based maintenance (CBM) of complex systems was pointed out last June at the previous Forum at Harrogate in 2007. In CBM, non-contact analysis of plant condition to faulty components (fuses, bearings, motors, steam pipes, gears, belts) can prevent costly shutdowns by corrective maintenance and breakdown prediction to enable pre-emptive action. Since HR infrared cameras are very expensive, digital super-resolution techniques can be used to create an HR image from low cost low-resolution (LR) images. Wavelength diversity spans the range from ultraviolet (0.1 microns) to infrared (1-100 microns). Thermal IR (infrared) images are focal plane IR detector (bolometer) array and lens combinations that give a visual representation of IR energy emitted. Thermal IR images can passively see all objects regardless of ambient light and thermography can give detailed images of invisible objects. IR thermography is safe, non-intrusive and efficient for identifying faults and overheating components. Images gathered by an array ofIR detectors (staring array, microscanning array) are inherently of limited resolution because of the constraints on the size of the pixels and geometry of the array. Trade-off between energy gathering capability and noise is required, especially because of the particular characteristics of IR image sequence acquisition including the presence of significant aliasing. This paper presents the super-resolution technique based on moving least squares for IR image sequence super-resolution. Results of super-resolution on simulated sets of undersampled degraded IR images are also presented. A procedure for higher-order whitening in the transmitting end and de-whitening in the receiving end is also considered within the overall framework of thermal image data acquisition, compression, coding and transmission of the data through communication channels followed by de-whitening and image sequence super-resolution at the receiving end.
A biography of open source software: community participation and individuation of open source code in the context of microfinance NGOs in North Africa and the Middle East

For many, microfinance is about building inclusive financial systems to help the poor gain direct access to financial services. Hundreds of grassroots have specialised in the provision of microfinance services worldwide. Most of them are adhoc organisations, which suffer severe organisational and informational deficiencies. Over the past decades, policy makers and consortia of microfinance experts have attempted to improve their capacity building through ICTs. In particular, there is strong emphasis on open source software (OSS) initiatives, as it is commonly believed that MFIs are uniquely positioned to benefit from the advantages of openness and free access. Furthermore, OSS approaches have recently become extremely popular. The OSS gurus are convinced there is a business case for a purely open source approach, especially across international development spheres. Nonetheless, getting people to agree on what is meant by OSS remains hard to achieve. On the one hand scholarly software research shows a lack of consensus and documents stories in which the OSS meaning is negotiated locally. On the other, the growing literature on ICT-for-international development does not provide answers as research, especially in the microfinance context, presents little empirical scrutiny. This thesis therefore critically explores the OSS in the microfinance context in order to understand itslong-term development and what might be some of the implications for MFIs. Theoretically I draw on the 3rd wave of research within the field of Science and Technology Studies –studies of Expertise and Experience (SEE). I couple the software ‘biography’ approach (Pollock and Williams 2009) with concepts from Simondon’s thesis on the individuation of technical beings (1958) as an integrated framework. I also design a single case study, which is supported by an extensive and longitudinal collection of data and a three-stage approach, including the analysis of sociograms, and email content. This case provides a rich empirical setting that challenges the current understanding of the ontology of software and goes beyond the instrumental views of design, building a comprehensive framework for community participation and software sustainability in the context of the microfinance global industry.
Patterns and Related Influencing Factors of Multiple Chronic Diseases Among the Elderly Based on Data Mining in Shanxi, China

Background: The presence of multiple chronic diseases has become a public health issue worldwide. The study aimed to explore the patterns and related influencing factors of multiple chronic diseases among the elderly so as to provide a scientific reference for the health management strategy, which is dedicated to the prevention and intervention for multiple chronic diseases. Methods: A cross-sectional study, which used a multi-stage random sampling way, was conducted among 3266 elderly aged 60 years and above in Shanxi. A chi square test was used to compare the sociodemographic factors. The data mining methods, including association rule and decision tree, were performed to explore the patterns and related influencing factors of multiple chronic diseases in the elderly.Results: The prevalence of multiple chronic diseases was 30.31%. According to the results of the association rules, there were 10 association patterns screened out. The first five multiple chronic disease patterns were atherosclerosis and hypertension, coronary heart disease and hypertension, diabetes and hypertension, stroke and hypertension, eye disease and hypertension. The decision tree model selected 5 related influencing factors of multiple chronic diseases, including age, smoking, family genetic history, fresh fruit intake frequency and education level, simultaneously generating 9 influence rules.Conclusions: Multiple chronic diseases were prevalent among the elderly, which patterns mainly consisted of two or three chronic diseases. Regarding the unmodifiable related influencing factors, including an older age, a family genetic history, and low education level, relevant departments should help the elderly to establish prevention knowledge and raise awareness of strongly related chronic diseases, so as to reduce the incidence and adverse consequences.
Aspects of Tar Sands Development in Nigeria

Abstract Development of Nigerian massive reserves of crude bitumen and associated heavy oil is imminent in view of the impacts that the huge importation of these materials and their products have on the nation's economy, coupled with the depleting reserves of Nigerian conventional oil. This article reviews the extent of the tar sands resources in Nigeria and highlights the appropriate production technology options and their environmental implications. The utilization potentials of these resources are also enumerated, as well as the government's role in achieving accelerated, long-term tar sands development in the country.
Modal and physical deflections of beams using distributed wire sensors

Distributed wire sensors are utilized to extract modal and physical deflections of composite beams. The sensors rely in their operation on a set of wires which are embedded off the neutral axes of the composite beams. The wires are arranged in a special manner which allows continuous monitoring of the deflection curve of the beam. The output signals of the wires are processed to determine the modal, linear and angular displacements at critical discrete points along the beam axis. The theoretical and experimental performance of the sensor is presented in both the time and frequency domains. Comparisons are given between the experimental performance of the distributed sensor and that of conventional laser sensors in order to demonstrate the accuracy and merits of the distributed sensor. The results obtained suggest the potential of this new class of sensors as a viable means for monitoring the static and dynamic deflections of flexible composite smart beams and plates.
Design of Shape Memory Alloy Actuators

This paper describes the design of shape memory alloy force and displacement actuators based upon the thermomechanical constitutive relations previously developed by the authors. Numerical simulations and design case studies are presented which show the utility and advantages of this method over design methods currently being used. The types of actuators described and analyzed include bias spring actuators, differential force actuators, and their hybrid systems. The design approach includes coupling between the one-dimensional thermomechanical constitutive relations and a lumped capacitance transient thermal analysis. The design approach described herein will provide a practical and convenient method for use in the design of shape memory alloy actuators.
Experimental Study on Rotor Dynamic Lift Determination for Agricultural Unmanned Aerial Vehicle (AUAV)

Actual dynamic lift is an important index to measure the load capacity of agricultural unmanned aerial vehicle (AUAV). In real operation, it is difficult to obtain the accurate value of dynamic lift, which is easily affected by environmental factors, such as wind and other disturbances. In this paper, a test platform, including hardware and software, has been developed. The main controller of the data acquisition system was PIC18F25K80, which could be used for PWM signal output and data communication. The experiment results showed that: the maximum mean absolute error of measurement system was less than 0.030kg. In addition, the pulse width of PWM signal was 1.0ms when the rotator speed was 0 rad/s, and then the rotator reached to the highest speed about 42.95 rad/s when pulse width equaled to 2.0 ms. Moreover, lift coefficient (k) of individual rotor to be tested was 0.003, and the maximum load weight of individual rotor was about 5.377 kg. The goodness of fit (R2) of curve which was obtained by the method of linearregression analysis was about 0.923. This experimental study validated the effectiveness of dynamic lift model of AUAV rotor and laid the foundation for real-time dynamic lift measurement of AUAV. KeywordsAgricultural Unmanned Aerial Vehicle (AUAV); Load Capacity; Rotor Dynamic Lift; Wireless Measurement and Control System; Rotator Speed
Analyzing of Dynamic Characteristics of Special CNC Machine Tool

The dynamic characteristics of machine tool is an important factor, which make affect on the cutting stability of machine tool. The poor dynamic characteristics will seriously affect the stability of cutting, make the low cutting efficiency and low machining precision, and also accelerate the wear of tools and even reduce the machine’s service life. So it is necessary to analyze the dynamic characteristics of machine tool, and according to the results of analysis to optimize structural parameters and motion parameters of the machine tools. This paper analyses the dynamic characteristics of machine bed and machined work piece of the CNC special machine tool for Kelly with the finite element software, and analysis of excitation characteristics of cutting tool. It also makes optimization design to the machine bed, through the analysis and optimization, the natural frequency and stiffness will be obviously improved. According to the structure and calculation of the motion parameters we can get the exciting force frequency to workpiece when it is cut, using interlocking tooth cutting method to replace the initial symmetrical cutting method in order to avoid the resonance produced in the cutting process and improve stability. The exciting frequency when cutting can be improved and the probability of resonance when cutting is lowered. All these ensure high efficiency and high stability cutting.
Research of design challenges and new technologies for floating LNG

ABSTRACT With the rate of worldwide LNG demand expected to grow faster than that of gas demand, most major oil companies are currently investing their resources to develop floating LNG-FLNG (i.e. LNG FSRU and LNG FPSO). The global Floating LNG (FLNG) market trend will be reviewed based on demand and supply chain relationships. Typical technical issues associated with FLNG design are categorized in terms of global performance evaluation. Although many proven technologies developed through LNG carrier and oil FPSO projects are available for FLNG design, we are still faced with several technical challenges to clear for successful FLNG projects. In this study, some of the challenges encountered during development of the floating LNG facility (i.e. LNG FPSO and FSRU) will be reviewed together with their investigated solution. At the same time, research of new LNG-related technologies such as combined containment system will be presented.
Longitudinally Invariant Elastic Structures Analyzed by the Meshless Mlpg Method Using 2.5D Approach

Abstract This paper presents a general 2.5D meshless MLPG methodology for the computation of the elastic response of longitudinally invariant structure subjected to the incident wave field. A numerical frequency domain model is established using the Fourier transform in time and longitudinal coordinate domains. This allows for significant reduction of computational effort required. In the MLPG method the Moving-Least Squares (MLS) scheme is employed for the approximation of the spatial variation of displacement field. No finite elements are required for the approximation or integration of unknowns. A small circular subdomain is introduced around each nodal point in the analyzed domain. Local integral equations derived from the governing equations are specified on these subdomains. Continuously non-homogeneous material properties are varying in the cross-section of the analyzed structure. A simple patch test is introduced to assess the accuracy and the convergence of developed numerical model. At the end of the paper, numerical examples illustrate the applicability of the proposed numerical formulation.
A Review of Signal Detection Using the Bispectrum with Applications in Underwater Acoustics

Abstract : This paper reviews attempts at signal detection in Gaussian noise using a higher order statistical (Higher Order Spectra (HOS) or polyspectra) technique. Examples comparing power spectral and bispectral analysis include the following topics: the identification of signals generated by a system of coupled nonlinear differential equations, radar backscatter processing and target identification, and a statistical treatment of the detection of narrowband harmonic components resulting in a Receiver Operating Characteristic (ROC) curve. The critical signal and noise probability density function (pdf) assumptions from polyspectra theory which must be met for more effective noise suppression relative to classical second order power spectral methods are: (1) discussed in relation to detection results as reported in the literature review; and, (2) illustrated via examples using both direct and indirect nonparametric Discrete Fourier Transform (DFT) bispectrums employing Fast Fourier Transforms (FFT) for both simulated and real data. The signal set consisted of pure tones and a hop code used in active sonar. Signal detection, Bispectrum, Underwater acoustics, Gaussian noise, Higher order spectra, Polyspectra.
A new suppressed carrier synchronizer with reduced phase jitter for QAM systems

A new simple carrier phase synchronizer for QAM systems with reduced phase jitter is proposed. A solution based on the extended Kalman filter (EKF) is applied as a near optimal solution for the tracking of the time-varying phase of the carrier. In a conventional DPLL (digital phase lock loop) used in carrier phase recovery, the loop filter gain is a constant while in the new method the gain is adaptively changed such that a greatly reduced phase jitter variance is achieved. We derive the new scheme and compare it to the conventional first order DPLL, both analytically and by simulations for QAM modulations, We test the case of 16-QAM as an example. Simulation results show that the obtained phase error variance is much smaller in moderate and high SNR cases, also with higher carrier phase noise than the one achieved with a constant loop filter gain.
Progress in rotor broadband noise research

The current status of research on various rotor broadband noise sources is reviewed. Theoretical modeling techniques which appear to have the most promise in the development of successful noise prediction capabilities are emphasized. The types of noise considered include: turbulence ingestion noise, blade self-noise due to turbulence passing the trailing edge, blade self-noise due to separated flow, and blade self-noise due to vortex shedding. Comparisons with experimental results are given, and present theoretical and experimental limitations are delineated to help identify areas of needed research.
Guidelines for Thermographic Inspection of Concrete Bridge Components in Shaded Conditions

Infrared thermography has the potential to detect subsurface delaminations before spalling develops and could be used to improve the visual inspection of concrete bridges. The technology has traditionally been applied to bridge decks, which are exposed to radiant heating from the sun that helps develop the necessary thermal gradients in the concrete. Thermal gradients can also be developed from normal diurnal temperature variations. Convective heat transfer develops the thermal gradients, although these thermal gradients are of much lower magnitude than those developed through radiant heating from the sun. This paper presents the results of a study to develop thermal imaging for the detection of subsurface deterioration in the soffit areas of bridges; these soffit areas are shaded and therefore are not exposed to radiant heating from the sun. Experimental studies and field testing were conducted and are described. This paper reports on guidelines developed for this application of the technology; the guidelines address the necessary environmental conditions to enable the detection of damage in bridge soffit areas. Specifically, the paper discusses the rates of change in ambient temperature needed to ensure that subsurface damage can be detected in shaded conditions. The paper also discusses the effect of wind speed on the detectability of subsurface damage in the shaded areas of a bridge, as well as the camera settings needed to ensure that an inspector can detect temperature anomalies associated with subsurface damage. A field example is provided to illustrate the application of the technology and highlight the required camera settings.
Optimization of the Mass Distribution and the Air Spaces in Multiple‐Element Soundproofing Structures

A method is evolved for predicting the transmission loss of soundproofing multiple‐element configurations containing any number of elements. The optimum distribution of mass between the impervious elements (fuselage skin panel, blanket septa, trim panel) is determined for a general theoretical configuration and for a typical aircraft structure. The theoretical improvement obtained by mass distribution optimization (approximately uniform distribution between the impervious elements) is about 3 to 6 dB in the low frequencies (below 500 cps) and 8 to 14 dB in the speech interference range (600 to 4800 cps). It is shown that a large increase in air spaces between elements is required to obtain only about 8‐ to 10‐dB improvement (in theory), neglecting contact flanking paths between the elements. Also, replacing air spaces with acoustical blankets produces small improvements (2 to 8 dB) at the cost of possible structural flanking transmission between the elements.It is also shown that covering a hard terminatin.
Iron nanoparticle surface treatment of carbon nanotubes to increase fatigue strength of steel composites

Abstract A simple, scalable, and reproducible method is used to decorate carbon nanotubes (CNTs) with metal nanoparticles (NPs). Decorating CNTs with iron NPs prior to forming steel-based metal matrix composites (MMCs) improves the high-cycle fatigue (HCF) strength of the MMC by more than 350% vs. plain 1084 steel and more than 100% vs. an MMC with untreated CNTs. An inverse correlation between CNT loading and tensile strength was observed. The CNT surface treatment uses an organic microenvironment surrounding suspended CNTs and emulsion chemistry to treat individual CNTs or small bundles. This process can be adapted to work with other metal NPs or CNT types. This work demonstrates the potential for metal-treated CNTs to further improve the HCF strength of MMCs and paves a pathway toward additional CNT-reinforced composites. Graphical Abstract
An experimental and computational study of approach air distribution for a finned-tube heat exchanger

The distribution of air flow approaching a finned-tube heat exchanger is one of the predominant factors influencing the heat exchanger's performance. This article describes a method for measuring and predicting the inlet air flow distribution using particle image velocimetry (PIV) and a computational fluid dynamics (CFD) model, highlighting the source and magnitude of air side maldistribution. The studied case was a single-slab, four-depth-row, louvered-fin heat exchanger installed vertically in a horizontal duct. The measured data showed that the air approaching this very simple test case generally maintained velocities of 1.25 ms−1 (4.1 fts−1) to 1.35 ms−1 (4.4 fts−1), but certain portions of the coil were completely obstructed, resulting in no air flow, and other portions realized velocities of over 1.7 ms−1 (5.6 fts−1). A CFD model of the air flow through this heat exchanger was developed based on a momentum resistance modeling approach. The CFD results agreed well with the PIV measurements, predicting the local velocities within 3% over most of the domain and within 10% in areas with the largest velocity gradients.