Miracle-dz/UniFAR-FTUs huggingface dataset:
The analysis of the withdrawal force curve of the wetting balance curve

In order to evaluate the withdrawal force curve that is shown in a typical wetting balance curve, a number of wetting balance tests were conducted in this study using Sn-37%Pb solder and copper plate samples whose shapes and immersion depths were varied for the purpose of this study. In the shape-effect experiment using vertical copper plate samples whose bottom corners were cut out in rectangles, a new step-like section appeared in the downfall segment of the wetting balance curve. According to the depth-effect experiment, the amount of time needed for the curve to reach the pinnacle of the withdrawal force curve increased in proportion to the immersion depths of the plates while the span of time taken for the drop of the curve was not affected by the depth. The decrease of the maximum measured force under the condition of a deeper immersion depth is attributable to the buoyancy force that also increases as the immersion depth gets deeper. It can be concluded from the results that: 1) the ascending profile of the withdrawal force curve in the typical force-time curve represents the sliding of solder on plates; 2) the highest point on the withdrawal force curve stands for the state in which the sliding solder meets the bottom corners of a normal vertical plate.
Wavelet denoising of partial discharge images

This paper presents application of wavelet based de-noising to partial discharge (PD) phase resolved images. Simulations are discussed in first part while in the second one results obtained during on-line measurements on a 6 kV motor. The basic principles of wavelet de-noising analysis, as well as examples of hard- and soft de-noising thresholding are reported. For the purposes of decomposition, the Deabuchies wavelet and wavelet packets at different levels were applied. The efficiency of the enhancement was measured by using a mean square signal-to-noise ratio and standard deviation to mean ratio.
Biofilm formation under high shear stress increases resilience to chemical and mechanical challenges

Abstract The effect that the hydrodynamic conditions under which biofilms are formed has on their persistence is still unknown. This study assessed the behaviour of Pseudomonas fluorescens biofilms, formed on stainless steel under different shear stress ( ) conditions (1, 2 and 4 Pa), to chemical (benzalkonium chloride – BAC, glutaraldehyde – GLUT and sodium hypochlorite – SHC) and mechanical (20 Pa) treatments (alone and combined). The biofilms formed under different showed different structural characteristics. Those formed under a higher were invariably more tolerant to chemical and mechanical stresses. SHC was the biocide which caused the highest biofilm killing and removal, followed by BAC. The sequential exposure to biocides and mechanical stress was found to be insufficient for effective biofilm control. A basal layer containing biofilm cells mostly in a viable state remained on the surface of the cylinders, particularly for the 2 and 4 Pa-generated biofilms. Graphical Abstract
Frequency-response masking approach for digital filter design: complexity reduction via masking filter factorization

It has been reported in several recent publications that the frequency response masking technique is eminently suitable for synthesizing filters with very narrow transition-width. The major advantages of the frequency response masking approach are that the resulting filter has a very sparse coefficient vector and that the resulting filter length is only slightly longer than that of the theoretical (Remez) minimum. The system of filters produced by the frequency response masking technique consists of a sparse coefficient filter with periodic frequency response and one or more pairs of masking filters. Each pair of the masking filters consist of two filters whose frequency responses are similar except at frequencies near the band-edges. In this paper, we present three methods for reducing the complexity of the masking filters. The success of our technique is due to the fact that each pair of the masking filters can be realized as a cascade of a common subfilter and a pair of equalizers. >
An optimized bidirectional lightning surge protection semiconductor device

This paper addresses the analysis of a bidirectional lightning surge protection power semiconductor device called the bidirectional breakover diode (BBD). The BBD has a high-speed response, high current capability, and low conduction and switching losses. The influence of the layout on the trigger and holding current values has been studied by means of two-dimensional (2-D) electrical simulations. The length of the peripheral N/sup +/ diffusion together with the location of the edge contact between the metallization and the P/sup +//N/sup +/ diffusions are crucial in optimizing the trigger mechanism and the trigger and holding current values. The turn on of the inner cells has also been analyzed by numerical simulations, showing the effect of the central parasitic P/sup +/NP/sup +/ bipolar transistor at the initial phase of the turn on process. Experimental results have been obtained from fabricated 180-V BBD devices with holding current values in the range of 150-250 mA. The BBD surge protection capability has been corroborated by impulsive tests using a 10/1000 /spl mu/s, 50 A, 1000 V, current pulse. In addition, transient losses have been monitored in order to improve the surge protection capability of the device. Finally, the static and dynamic BBD thermal behaviour has also been analyzed.
Control and performance of a fully-digital-controlled shunt active filter for installation on a power distribution system

This paper presents a fully-digital-controlled shunt active filter for harmonic termination of a power distribution system. The main purpose of the active filter based on voltage detection is not to compensate for current harmonics but to damp out harmonic propagation caused by line inductors and shunt capacitors for power factor correction. However, time and phase delays inherent in digital controllers might lead to unsatisfactory harmonic-damping performance although digital controllers are preferable to analog controllers. This paper deals with the design and implementation of a digital controller for a shunt active filter based on voltage detection. Experimental results obtained from a laboratory system developed in this paper verify the viability and effectiveness of the fully-digital-controlled active filter.
R&D program on multisegmented piezoelectric bimorph mirrors at the ESRF: status report

This paper gives an overview of the current performances of the ESRF multi-segmented piezoelectric bimorph mirrors. These devices effectively combine the possibility of varying dynamically the average spherical bending radius with the capability of acting locally on the reflecting surface shape. A first generation consisting of two prototypes was completely characterized in the ESRF metrology laboratory and the mirrors are installed and fully operational on the ID26 and ID32 beamlines since October 1997. Results obtained during the characterization and the commissioning of these devices are presented. A second generation prototype mirror has been designed, manufactured, tested in the ESRF meteorology laboratory, installed and commissioned at ID26 in 1998. This last mirror exhibits sub- (mu) rad residual slope error rms in its central portion, 1 angstrom rms averaged microroughness a d can routinely achieve a vertical beam size as small as 7 micrometers FWHM at a focal distance of almost 3 m.
Experimental study of embedding motion and holding power of drag embedment type anchor on hard and soft seafloor

ABSTRACT As larger ships and floating offshore structures are, and rougher the marine environment becomes nowadays, a drag embedment type anchor of more stable performance and higher holding power is requested. This paper describes an experimental study of the drag embedding motion and the resultant holding force of three types of drag embedment type anchor model (HALL, AC-14, SEC POOL-N, scale 1/10).
Measurement of Adaptation to an Unfamiliar ATC Interface

Eight Air Traffic Controllers (four experienced practicing controllers and four trainee controllers) carried out four simulation exercises (one low, three high traffic load) using a TRACON II ATC Simulator during one afternoon, the morning being used for familiarization and initial training. Performance during each exercise was recorded. A self-assessment questionnaire for fatigue and a sample of saliva was taken for cortisol analysis before and after each experimental session. The NASA-TLX was completed after each exercise. Experienced controllers more affected by the task, and learned more efficiently. The methods under investigation are now being transferred to full-scale Real-Time simulations.
The System and Self-Reference of The App Economy: the Case of Angry Birds

This article presents a preliminary analysis of the app system, mainly in relation to mobile technology. By observing the app system (application system), it sets out to describe and understand its social evolution. Employing Niklas Luhmann’s systems theory to examine the popular app game Angry Birds, this study describes the internal structure of the app system, which, in theory, acts as a social sub-system, displaying the following themes and features – fi rst, app software and the broader social system interact and rely heavily on each other, so that, within the existing capitalist market, such interdependence clearly enables the social system-based app sub-system to establish the app platform, the app structure and, even more importantly, the simplifi ed inner principle of apps’ ‘use and download’ function. Second, credited to the mobile terminal, these set principles within the capital market are able to construct a system boundary and inner structure of their own. Third, the software (app) library and quantity of downloads become the common theme (shared concept) used to project the activities of the system. This (re)formulates and simplifi es the complexity of the original system environment to create the self-refl exive app system. Finally, such refl exivity allows the app system to self-generate and maintain itself. Although its functions may have been wellintegrated within the social system, the app system represents a closed type of self-contained/self-production mechanism.
Experimental models of series and shunt elements in coplanar MMICs

Experimental models of several grounded coplanar waveguide discontinuity structures, such as series and shunt inductors and capacitors, have been developed using experimental measurements and computer optimization. The equivalent circuit models have been derived in terms of structural parameters of the discontinuity structures to facilitate their easy use in the design of coplanar MMICs (monolithic microwave integrated circuits). These simple models can be integrated with any simulation program to facilitate their easy use. <<ETX>>
Supplement materials for publication: Modelling evaporation with local, regional and global BROOK90 frameworks: importance of parameterization and forcing.

Abstract. Observation and estimation of evaporation is a challenging task. Evaporation occurs on each surface and is driven by different energy sources. Thus the correct process approximation in modelling of the terrestrial water balance plays a crucial part. Here, we use a physically-based 1D lumped soil-plant-atmosphere model (BROOK90) to study the role of parameter selection and meteorological input for modelled evaporation on the point scale. Then, with the integration of the model into global, regional and local frameworks, we made cross-combinations out of their parameterization and forcing schemes to analyse the associated model uncertainty. Five sites with different land uses (grassland, cropland, deciduous broadleaf forest, two evergreen needleleaf forests) located in Saxony, Germany were selected for the study. All combinations of the model setups were validated using FLUXNET data and various goodness of fit criteria. The output from a calibrated model with in-situ meteorological measurements served as a benchmark. We focused on the analysis of the model performance with regard to different time-scales (daily, monthly, and annual). Additionally, components of evaporation are addressed, including their representation in BROOK90. Finally, all results are discussed in the context of different sources of uncertainty: model process representation, input meteorological data and evaporation measurements themselves.
Detecting Internet of Things Bots: A Comparative Study

Since the Mirai botnet attacks in 2016 research into the Internet of Things (IoT) botnet malware has increased substantially. IoT botnet relevant threats continue to rise, impacting businesses and users. This paper aims to contribute to the problem space by compiling and synthesizing the relevant literature over the last five years to provide an overview of the most recent advances in IoT botnets, their detection and prevention, and laying down the future research directions required to better address this ever growing threat.
Experiences from the Field: A Qualitative Study Exploring Barriers to Maternal and Child Health Service Utilization in IDP Settings Somalia

Background In Somalia, maternal and child health service utilization is unacceptably low. Little is known about factors contributing to low maternal and child health service utilization in Somalia, especially in internally displaced people (IDP) settings. This study aimed to understand barriers to the use of maternal and child health-care services among IDPs in Mogadishu. Methods A total of 17 in-depth interviews (IDIs), 7 focus group discussions (FGDs), and field observations were conducted on lactating/pregnant mothers, health-care providers, traditional birth attendants (TBA), and IDP camp leaders. The socio-ecological model (SEM) framework was employed for the categorization of barriers to healthcare utilization and further analysis was conducted to understand the major types and nature of barriers. Results Using the SEM, the following major barriers that hinder maternal and child health service utilization were identified. Low socio-economic, lack of decision making power of women, TBA trust, poor knowledge and awareness on pregnancy danger signs, fear of going to unfamiliar areas were identified barriers at individual level. Traditional beliefs, male dominance in decision making, and lack of family support were also identified barriers at interpersonal level. Security and armed conflict barriers and formidable distance to health facility were identified barrier at the community level. Lack of privacy in the facility, transportation challenges, poor functional services, negative experiences, closure of the health facility in some hours, and lack of proper referral pathways were identified barriers at organizational or policy level. Conclusion Overall, various factors across different levels of SEM were identified as barrier to the utilization of maternal and child health services. Hence, multi-component interventions that target these complex and multifaceted barriers are required to be implemented in order to improve maternal and child health services utilization among IDP in Mogadishu, Somalia.
High-Precision UWB-Based Localisation for UAV in Extremely Confined Environments

In this paper, a high-precision ultra-wideband (UWB) based unmanned aerial vehicle (UAV) localisation approach is proposed for applications in extremely confined environments. It is motivated by the emerging demand on autonomous inspection in such environments that are hard or impossible for humans to access. Instead of the traditional localisation techniques such as global positioning system (GPS), vision based or other localisation techniques, the UWB based localisation technique is adopted for precise UAV positioning due to its high accuracy, implementation simplicity and suitability in such environments. To avoid the requirement on strict synchronisation between sensor nodes and provide decimetre-level accuracy, the proposed algorithm combined the two-way time-of-flight (TW-TOF) localisation scheme with the maximum likelihood estimation (MLE) method. This differs from applications in other environments, the number and deployment area of anchor nodes are highly restricted in such environments. Therefore, an in-depth investigation for the anchor deployment strategies is presented to find the most suitable geometry configurations with accurate and robust performance. Finally, extensive simulations, static experiments and flight tests have been conducted to validate the localisation performance under different deployment strategies. The experiments show that average localisation error and standard deviation (STD) under 0.2 m and 0.07 m are obtainable by using our proposed approach under three different geometry configurations of anchor nodes. This is suitable for different applications in extremely confined environments.
Optimal Combination of Multivariate Filter Feature Selection and Classifier for Speech-Based Depression Detection

In this paper, we have focused to improve the performance of a speech-based uni-modal depression detection system, which is non-invasive, involves low cost and computation time in comparison to multi-modal systems. The performance of a decision system mainly depends on the choice of feature selection method and the classifier. We have investigated the combination of four well-known multivariate filter methods (minimum Redundancy Maximum Relevance, Scatter Ratio, Mahalanobis Distance, Fast Correlation Based feature selection) and four well-known classifiers (k-Nearest Neighbour, Linear Discriminant classifier, Decision Tree, Support Vector Machine) to obtain a minimal set of relevant and non-redundant features to improve the performance. This will speed up the acquisition of features from speech and build the decision system with low cost and complexity. Experimental results on the high and low-level features of recent work on the DAICWOZ dataset demonstrate the superior performance of the combination of Scatter Ratio and LDC as well as that of Mahalanobis Distance and LDC, in comparison to other combinations and existing speech-based depression results, for both gender independent and gender-based studies. Further, these combinations have also outperformed a few multimodal systems. It was noted that low-level features are more discriminatory and provide a better f1 score.
The Falls Efficacy Scale International is a valid measure to assess the concern about falling and its changes induced by treatments

Objective To test with the Rasch analysis the psychometric properties of the Falls Efficacy Scale International, a questionnaire for measuring concern about falling. Design Longitudinal observational study, before–after rehabilitation. Setting Inpatient rehabilitation. Subjects A total of 251 neurological patients with balance impairment. Interventions Physiotherapy and occupational therapy aimed at reducing the risk of falling. Main measures Participants (median age, first–third quartile: 74.0, 65.5–80.5 years; stroke and polyneuropathy: 43% and 21% of the sample, respectively) received a balance assessment (Falls Efficacy Scale International included) pre- and post-rehabilitation. Rasch analysis was used to evaluate the Falls Efficacy Scale International. Differential item functioning, which assesses the measures’ stability in different conditions (e.g. before vs. after treatment) and in different groups of individuals, was tested for several variables. Results Patients suffered a moderate balance impairment (Mini-BESTest median score; first–third quartile: 15; 11–19), mild–moderate concern about falling (Falls Efficacy Scale International: 28; 21–37) and motor disability (Functional Independence Measure, motor domain: 70.0; 57.0–76.5). Falls Efficacy Scale International items fitted the Rasch model (range of infit and outfit mean square statistics: 0.8–1.32 and 0.71–1.45, respectively) and the questionnaire's reliability was satisfactory (0.87). No differential item functioning was found for treatment, gender, age and balance impairment. Differential item functioning was found for diagnosis and disability severity, but it is shown that it is not such as to bias measures. Conclusions Falls Efficacy Scale International ordinal scores can be turned into interval measures, i.e. measures of the type of temperature. Being differential item functioning-free for treatment, these measures can be safely used to compare concern about falling before and after rehabilitation, such as when interested in assessing the rehabilitation effectiveness.
Improvement of iris location accuracy in iris recognition

Locating the pupil circle is an important step in iris recognition. As the light shines on the pupil, a bright reflection spot is formed in the iris image. In the process of iris location using Hough transform, location accuracy will be affected, because the reflection spot cannot be eliminated in practical optical system. Therefore, we proposed an algorithm to eliminate the reflected light spot in the pupil. The average gray value of the iris image can be obtained by using the gray histogram of the iris image. Then convolution of iris image with summation matrix of ten by ten is obtained, and the sum of gray values is less than a hundred times the average gray value and the approximate position of pupil can be found out. The pupil position is used to get the1 approximate position of the reflected highlight spot. The threshold is set to average threshold plus 128, and the point in the pupil field that is larger than the threshold can be obtained, and the position of the reflection point can be determined. The positions of the spot are set to zero. Using the algorithm, the number of highlight point in the binary iris image is reduced effectively. Thus Hough circle location would get higher location accuracy.
Optimisation of Mould Filling Parameters of the Compression Resin Transfer Moulding Process

The Compression Resin Transfer Moulding Process (CRTM) is a popular type of Liquid Composite Moulding Process (LCM) commonly used for manufacturing composite materials. In this paper we consider the optimisation of the manufacturing processing time and the machine tooling force for the CRTM process. Since this process requires large forces during compression, force evaluation and prediction provides great advantages for the industry as it enables structural analysis of the moulds. Not only it does lead to cost effective tooling design, it also allows for proper selection of cost effective moulds and supporting equipment. The tooling force, moreover, is in conflict with manufacturing time, which is another objective of particular interest in the industry. In recent years, the advancement of CRTM simulation software allows accurate prediction of the processing objectives thus making it unnecessary to run through the expensive experiments physically. In this process, we use such a simulation software called SimLCM and combine it with a popular NSGA-II evolutionary multi-objective optimisation (EMO) algorithm to optimise maximum tooling force and processing time with respect to three manufacturing parameters. The EMO algorithm uses SimLCM as a black box to evaluate the objective function values for a population of solutions. We report results on a simple rectangular plate model (for calibration) and an industrial example.