Miracle-dz/UniFAR-FTUs huggingface dataset:
Estimating Heart Rate from Unlabelled Video

We describe our entry for the ICCV 2021 Vision4Vitals Workshop [6] heart rate challenge, in which the goal is to estimate the heart rate of human subjects from facial video. While the challenge dataset contains extensive training data with ground truth blood pressure and heart rate signals, and therefore affords supervised learning, we pursue a different approach. We disregard the available ground truth blood pressure data entirely and instead seek to learn the photoplethysomgraphy (PPG) signal visible in subjects’ faces via a self-supervised contrastive learning technique. Since this approach does not require ground truth data, and since the challenge competition rules allow it, we therefore can train directly on test set videos. To boost performance further, we learn a supervised heart rate estimator on top of our "dis-covered" PPG signal, which more explicitly tries to match the ground truth heart rate. Our final approach ranked first on the competition test set, achieving a mean absolute error of 9.22 beats per minute.
Effect of Cathode Position on Hall-Effect Thruster Performance and Cathode Coupling Voltage

Hall-e ect thruster performance as a function of cathode position is explored through a series of experiments in which performance is monitored while the cathode is translated via a 2-axis motion table. Significant changes in thrust, e ciency, and cathode coupling voltage are observed. E ciency changes as great as 12% are measured. Cathode coupling voltages typically move closer to ground as the cathode is moved away from the thruster in the radial direction and as it is moved forward of the exit plane. Corresponding improvements in performance are measured. However, the improvements in performance are greater than can be explained by the change in cathode coupling voltage alone.
Analysis of Basic Phenomena in Boiling Channel Instabilities with Different Flow Models and Numerical Schemes

The results of a computational study on boiling channel stability are here discussed. The study compares the information obtained by two programs, developed in previous work for the linear and the nonlinear stability analysis of boiling channels basing on a simplified flow model, with the predictions of a well known system code. The phenomena highlighted by the results of the system code, adopted with different flow models and numerical methods, are discussed in a systematic way with the aid of the description obtained by the simplified model, in order to obtain a clearer picture than could be achieved by the mere application of the system code to conditions of interest for boiling water reactor stability. The effects on the obtained results of non-equilibrium, numerical discretization and number of nodes are considered, evaluating their influence on the predicted stability boundaries. Some physical aspects of the density-wave mode of instability are finally discussed basing on the predictions obtained by the different models.Copyright © 2006 by ASME
Sthe Study on Twin Structure by Gaussian Laser Ablation of Copper

Laser ablation will produce complex twin boundaries in the single crystal copper target material, thereby changing its mechanical properties. In this work, a two-temperature model combined with molecular dynamics and time-dependent laser has been used to study the ablation results of copper nano-column. The time-dependent Gaussian laser function has been proven to have trustworthy simulation results and it was found that the twin boundary in the initial nano-copper column model will affect the generation of twins after ablation. It gives an idea that we can use the twin structure in the material to produce more twins.
A Neomillennial Learning Approach: Helping Non-Traditional Learners Studying at a Distance

[Abstract]: Relying on text-based instruction may be disenfranchising many students, whilst technology enhanced environments can provide significant advantages to a growing market of non-traditional learners. This paper reports on research investigating the perceptions of first year distance education students studying a foundation communications course using a multimodal learning environment. It demonstrates higher levels of engagement are possible when a neomillennial learning approach is adopted for designing course materials catering to a diverse student body, whilst maintaining a balanced environment for more traditional learners. A strong acceptance was moderated by a desire to still receive some print-based materials. However, students reported a preference to receive an electronic version when given a choice.
A Pilot Study on Long-term Physiological Signal Monitoring using Anhydrous Viscoplastic Electrodes

Electrocardiography (ECG) and Electromyogram (EMG) are widely used to help physicians to diagnose various diseases. Besides, long-term physiological signals monitoring is of great significance for circumstances where certain diseases may not be observed in short-term monitoring. At present, wet electrodes are widely used in the clinic and are considered as a standard method to acquire physiological signals in high fidelity. However, current wet electrodes achieve high-quality signal acquisition by using conductive gel which will dry up as time elapses and finally leads to degradation of the signal quality. Therefore, an anhydrous viscoplastic electrode was proposed in this paper to solve the abovementioned problem. The proposed electrode, which is anhydrous and viscoplastic, enables high quality physiological signal acquisition with firm contact with the skin and it will not dry up within a long period of time. The results showed that the impedance of the proposed viscoplastic electrode could maintain relative stability after two days while that of the gel electrodes would increase significantly due to the gel dried up. Besides, the proposed electrode obtained physiological signals with high quality in both ECG and EMG tasks. After 24 hours of monitoring, the signal quality of the proposed electrode remained unchanged, indicated by the clearly recognizable time-domain signals. However, the signal waveform completely submerged in noise after the gel dried up. Moreover, the superior performance of the viscoplastic electrodes could be confirmed by the SNR difference between the two days, SNR further confirmed the superiority of the, with -2.03±2.10 dB and -3.40±8.27 dB for ECG and EMG respectively, and the SNR difference of gel electrodes were -7.59 ± 5.70 dB and -35.39±15.71 dB respectively. The proposed electrodes could be a great candidate for long-term physiological signal monitoring in risk management of healthcare.Clinical Relevance— The proposed electrode could achieve long-term physiological signals monitoring with high quality.
Enhancing Current Cardiorespiratory-based Approaches of Sleep Stage Classification by Temporal Feature Stacking

This paper presents a generic method to enhance performance and incorporate temporal information for cardiorespiratory-based sleep stage classification with a limited feature set and limited data. The classification algorithm relies on random forests and a feature set extracted from long-time home monitoring for sleep analysis. Employing temporal feature stacking, the system could be significantly improved in terms of Cohen’s κ and accuracy. The detection performance could be improved for three classes of sleep stages (Wake, REM, Non-REM sleep), four classes (Wake, Non-REM-Light sleep, Non-REM Deep sleep, REM sleep), and five classes (Wake, N1, N2, N3/4, REM sleep) from a κ of 0.44 to 0.58, 0.33 to 0.51, and 0.28 to 0.44 respectively by stacking features before and after the epoch to be classified. Further analysis was done for the optimal length and combination method for this stacking approach. Overall, three methods and a variable duration between 30 s and 30 min have been analyzed. Overnight recordings of 36 healthy subjects from the Interdisciplinary Center for Sleep Medicine at Charité-Universitätsmedizin Berlin and Leave-One-Out-Cross-Validation on a patient-level have been used to validate the method.Clinical relevance— The method can be employed generically to feature sets for (small scale) datasets to improve classification performance for classification problems with temporal relations with random forest classifiers.
PEBL: Pessimistic Ensembles for Ofﬂine Deep Reinforcement Learning

Ofﬂine reinforcement learning (RL), or learning from a ﬁxed data set, is an attractive alternative to online RL. Ofﬂine RL promises to address the cost and safety implications of taking numerous random or bad actions online, a crucial aspect of traditional RL that makes it difﬁcult to apply in real-world problems. However, when RL is na¨ıvely applied to a ﬁxed data set, the resulting policy may exhibit poor performance in the real environment. This happens due to over-estimation of the value of state-action pairs not sufﬁciently covered by the data set. A promising way to avoid this is by applying pessimism and acting according to a lower bound estimate on the value. In deep reinforcement learning, however, uncertainty estimation is highly non-trivial and development of effective uncertainty-based pessimistic algorithms remains an open question. This paper introduces two novel ofﬂine deep RL methods built on Double Deep Q-Learning and Soft Actor-Critic. We show how a multi-headed bootstrap approach to uncertainty estimation is used to calculate an effective pessimistic value penalty. Our approach is applied to benchmark ofﬂine deep RL domains, where we demonstrate that our methods can often beat the current state-of-the-art.
Providing and validating a model for applying critical thinking in accounting education in universities

Today, one of the most important challenges for universities is the teaching of academic disciplines; Including accounting. One of the major challenges of the 21st century is how to educate students who are prepared to face a dynamic and changing society. One of the major challenges of the 21st century is how to educate students who are prepared to face a dynamic and changing society. The accounting learning process should be designed to develop students’ ability to think critically. Therefore, providing a model for using critical thinking in accounting education in the universities has been considered by researchers. In this study, after identifying and classifying the factors affecting accounting education, the obtained model was tested by Structural Equation Modeling. The statistical population of the research in the qualitative part included prominent teachers of accounting and in the quantitative part included teachers and doctoral students of accounting universities. The sample size was 12 in the qualitative part and 286 in the quantitative part. The results of extracted pattern showed that; The dimensions of causal conditions have a significant effect on axial conditions. Axial phenomenon, Contextual conditions, and intervening conditions have had a significant impact on strategies. Also, strategies have had a significant impact on the consequences. In the end, the main index of Grounded Theory model was favorable fit.
Fruits Puree and its Application as Fat Replacers in Biscuits

This study was carried out to evaluate the effect three types of fruits puree (apple, banana, and cantaloupe) used as fat replacers at three ratios to fat (50:50, 75:25 and 100:0) w/w and high fat biscuit control (100% fat) to compare in baking biscuits on the chemical composition, physical and functional properties, and sensory evaluation of the biscuits. The results revealed that there was no significant difference between all samples in moisture as compared to the control sample. The highest content of moisture in samples 100% fat replacement was 2.59%. The fiber, ash and carbohydrate content of the biscuits increased significantly as the replacement level increased. In contrast, the replacement resulted in a sharp significant decrease in fat content. The results increased significantly at (p≤0.05) among samples in weight and thickness of biscuits but the width, volume and specific volume decreased. The highest value of weight and thickness was in samples of 100% fat replacement ( 20.0%, 20.01% and 16.33%) in formulas (2,3,4) respectively, and the lowest was found in 50% fat replacement (16.0%, 13.67% and 12.52%). PH of all samples was not significantly different as compared to the control sample. The water absorption capacity of samples 100% fat replacers had higher than the 50% fat replacers. The appearance, flavor, taste, texture and overall acceptance, of all biscuits replaced with fruits puree exhibited no significant difference as compared to their control and was highly acceptable except appearance and texture in 100% fat replacers of apple were significant differences at (p≤0.05).
Re-thinking ‘harm’ in relation to children’s work: a ‘situated,’ multi-disciplinary perspective

ABSTRACT The UN calls for the elimination of child labour by 2030, and its ‘worst forms’ by 2025. Implicit in this mandate is the assumption that children’s work is harmful, yet no coherent theory of harm exists within the child labour field. Moreover, evidence suggests that simply removing children from supposedly harmful work is often damaging. This paper explores how harm may be understood and identified in the context of children’s work. It reviews and synthesises literature from multiple disciplines, pointing towards a more situated and nuanced approach to harm that incorporates both ‘subjective’ and ‘objective’ dimensions.
Two-port scattering at an elliptic-waveguide junction

A concentric waveguide junction consisting of an elliptic waveguide has been formulated using the mode-matching method. The formulation is a generalized solution of the problem such that the second waveguide, which forms the junction, can be any regular shape in cross section. Exact closed-form expressions for computing the coupling integrals have been obtained from the generalized formulation. As a special case of the general solution, the expressions for evaluating the coupling integrals of rectangular-to-elliptic, circular-to-elliptic, and elliptic-to-elliptic waveguide junction are given. Theoretical results compare well with the experimental and published results.
Utilization of Obstetric Analgesia for Labor Pain Management and Associated Factors among Obstetric Care Providers in Public Hospitals of Addis Ababa, Ethiopia: A Cross-Sectional Study

Background In low-income countries, pain-free labor initiative is an emerging concept and still parturient undergoes through painful labor; this is not different in Ethiopia; despite the national direction to use analgesia for labor pain and strong demand from the women, evidence on utilization of obstetric analgesia for labor pain management in Ethiopia is scarce. The objective of this study was to assess level of obstetric analgesia utilization and associated factors among obstetric care providers in public hospitals in Addis Ababa, Ethiopia. Methods An institution-based cross-sectional study was used. All obstetric care providers working in labor and delivery units in public hospitals in Addis Ababa were included. The data were collected using a self-administered structured questionnaire. After checking for completeness, data were entered into Epi-data 3.1 and analyzed using SPSS 20. Bivariate and multivariable logistic regressions were used to identify factors associated with utilization of obstetric analgesia. Result Of 391 obstetric care providers included in the study, 143 (36.6%; 95% CI: 31.5–40.9%) reported providing labor analgesia. Having adequate knowledge (AOR 2.7; 95% CI: 1.37–5.23), ten and more years of work experience (AOR 4.3; 95% CI: 1.81–10.13), and availability of analgesics (AOR 3.3; 95% CI: 1.99–5.53) were significantly associated with providing labor analgesia. Conclusion Slightly more than 3 in 10 obstetric care providers reported providing labor analgesics to women. Training of providers and ensuring adequate supply of analgesics is required to make sure that women in labor would not suffer from labor pain.
Evaluation of displacement‐based vulnerability assessment methodology using observed damage data from Christchurch

On 22 February 2011, Christchurch City experienced a destructive magnitude (Mw) 6.2 aftershock following the main event of magnitude (Mw) 7.1 on the 4 September 2010. Severe damage was inflicted on the building stock, particularly within the central business district (CBD) of Christchurch. The strong motion stations around the CBD region and extensive building damage survey information from the Christchurch City Council provided a unique opportunity to calibrate a theoretical regional vulnerability assessment model developed and refined to be applicable for New Zealand (NZ) buildings. In this study, data from the building safety evaluation survey conducted by Christchurch City Council are synthesised and processed to extract details on building typologies in the CBD region and the colour tagging assigned to each building depending on the degree of damage.
An approach to achieve reusability of electronic modules

Electronic devices are very complicated industrial products with a negative environmental impact. Until now, little profit can be expected from the recycling process. Faced with this situation, it will be of great benefit to enable the re-use of modules recovered from discarded devices. Besides obstacles like innovation pressure, a main difficulty in the realization of re-use lies in the lack of life history data of used modules. In this paper, an approach is presented to tackle this problem. First it is shown that re-use requires a modular product structure. A data storage unit called "identification unit" is then introduced for each module of interest in a product. Important life history data are collected and recorded in the identification unit together with information on the product and applied materials. All data are accessible through a so-called "green port" interface. The data stored in the identification units are structured according to their purposes and manufacturer's intention. In line with demands in the market, the data stored in identification units can be used to find out which modules still have a relatively high residual value. Through the introduction of indentification units in electronic products, necessary life history information is made available which is a prerequisite for the realization of re-use as a form of high level recycling. <<ETX>>
Life cycle assessment of low-rise office building with different structure–envelope configurations

This paper presents life cycle assessment approach to study the impact of structure and envelope types on the energy consumption and environmental impact of an office building in New York City, USA. In addition, the future costs of environmental impact for various structure and envelope options are assessed according to the current practice and market price of CO2. Eight structure and envelope types for the low-rise office building are investigated, which include concrete and steel structures with various combinations of envelopes. The parameters such as life cycle energy use, global warming potential, and water, air and land emissions are analyzed. The energy simulation is performed by using eQUEST software while the environmental impact is assessed by using ATHENA® impact estimator. The building with concrete frame is proved to have lower environmental impact compared to that with steel frame. The precast concrete building is found to be the most economical alternative due to the minimal environmental i.
Shipping noise impacts on marine life

Concerns about the impact of noise of shipping on marine life, has led to the recent publication by the International Maritime Organisation of guidelines for the reduction of noise from commercial shipping. This paper puts the noise from shipping in context with other sounds in the ocean, addresses the potential impact of noise from shipping, the difficulties of assessing the impact and the likely effectiveness of mitigation measures. It draws on underwater noise studies around Australia that included areas of low shipping densities, allowing reliable characterisation of natural ambient noise at frequencies of shipping noise. This low frequency ambient noise has been difficult to determine in the high shipping areas where most ambient noise studies have been made. The paper also draws on studies of the effects of noise on marine mammals. Noise from many distant ships across an ocean basin produces a general nondescript background noise known as “traffic noise” where the contribution of any single ship is not detectable. Noise from a nearby ship reaches higher levels than traffic noise but is present for short times and close distances. Noise from a close ship can be positive if it causes an animal to move away and avoid collision.
A SYNTHESIS OF SLOAN-C EFFECTIVE PRACTICES

Encouraging continuous improvement in the quality, scale and breadth of online education, the Sloan Consortium invites practitioners to share effective practices. This report synthesizes effective practices submitted by Sloan-C members to the online collection at http://www.sloanconsortium. org/effective as of December 2009. The synthesis includes links to the provider institutions and to detailed postings about practices.
Applications of Healthcare Robots in Combating the COVID-19 Pandemic

Due to the increasing number of COVID-19 cases, there is a remarkable demand for robots, especially in the clinical sector. SARS-CoV-2 mainly propagates due to close human interactions and contaminated surfaces, and hence, maintaining social distancing has become a mandatory preventive measure. This generates the need to treat patients with minimal doctor-patient interaction. Introducing robots in the healthcare sector protects the frontline healthcare workers from getting exposed to the coronavirus as well as decreases the need for medical personnel as robots can partially take over some medical roles. The aim of this paper is to highlight the emerging role of robotic applications in the healthcare sector and allied areas. To this end, a systematic review was conducted regarding the various robots that have been implemented worldwide during the COVID-19 pandemic to attenuate and contain the virus. The results obtained from this study reveal that the implementation of robotics into the healthcare field has a substantial effect in controlling the spread of SARS-CoV-2, as it blocks coronavirus propagation between patients and healthcare workers, along with other advantages such as disinfection or cleaning.
Analytical expressions for harmonic distortion at low frequencies due to device mismatch in CMOS current mirrors

One of the origins of harmonic distortion in current mirrors is the inevitable mismatch between the mirror transistors. In this brief, we examine both single current mirrors and complementary class-AB current mirrors, and develop analytical expressions for the mismatch-induced harmonic distortion. The expressions are verified through simulations and are used for a discussion of the impact of mismatch on harmonic distortion properties of CMOS current mirrors. The distortion model is combined with well-known statistical models for the device mismatch in order to establish a relation between geometrical parameters, distortion, and production yield. It is found that distortion levels somewhat below 1% can be attained by carefully matching the mirror transistors, but ultra-low distortion is not achievable,.