Transformer-based Self-supervised Multimodal Representation Learning for Wearable Emotion Recognition

Recently, wearable emotion recognition based on peripheral physiological signals has drawn massive attention due to its less invasive nature and its applicability in real-life scenarios. However, how to effectively fuse multimodal data remains a challenging problem. Moreover, traditional fully-supervised based approaches suffer from overfitting given limited labeled data. To address the above issues, we propose a novel self-supervised learning (SSL) framework for wearable emotion recognition, where efficient multimodal fusion is realized with temporal convolution-based modality-specific encoders and a transformer-based shared encoder, capturing both intra-modal and inter-modal correlations. Extensive unlabeled data is automatically assigned labels by five signal transforms, and the proposed SSL model is pre-trained with signal transformation recognition as a pretext task, allowing the extraction of generalized multimodal representations for emotion-related downstream tasks. For evaluation, the proposed SSL model was first pre-trained on a large-scale self-collected physiological dataset and the resulting encoder was subsequently frozen or fine-tuned on three public supervised emotion recognition datasets. Ultimately, our SSL-based method achieved state-of-the-art results in various emotion classification tasks. Meanwhile, the proposed model proved to be more accurate and robust compared to fully-supervised methods on low data regimes.Comment: Accepted IEEE Transactions On Affective Computin

Performance of coolant strategies when turning hardened martensitic stainless steel using tialn coated carbide tool

Coolant strategies in turning hardened stainless steel are important, due to the fact that heat cannot be removed efficiently from the cutting area. This heat issue shortens the tool life and reduces machined surface integrity, resulting in higher machining cost and lower productivity. Conventional cutting fluids cause health problems, workshop pollution and higher recycling cost. Dry, minimum quantity lubricant (MQL) and cryogenic machining are alternatives of green coolant to eliminate conventional cutting fluids. Thus, the objective of this research is to study the feasibility and performance of using new green coolant strategies that contribute to the sustainable process. Experiments were carried out in two different stages when turning 48 ±1 HRC martensitic stainless steel (AlSI420) uses a wiper PVD-TiAIN coated carbide cutting tool. Cutting speeds (l00, 135, and 170 m/min) and feed rates (0.16, 0.2, and 0.24 mm/rev) were investigated. The depth of cut was kept constant at 0.2 mm. Nitrogen gas pressure was 0.5 MPa and the oil mist (castor oil) flow rate was 40 ml/h. In the first stage, comparison between three cutting conditions were evaluated, namely cold nitrogen gas (cold N2), nitrogen gas with oil mist (N2+MQL) and cold nitrogen gas with oil mist conditions (cold N2+MQL). Dry cutting was used as the benchmark. In the second stage, the best cutting condition from first stage was used for further experiments to investigate the effect of cutting speed and feed on machining responses such as tool life (TL), volume of material removed (VMR), surface roughness (Ra) and cutting forces (Fx, Fy and Fz), chip morphology and microstructures of machined surface. Full factorial design was used to model the relationship between cutting responses (tool life, surface roughness, and cutting forces) and different cutting speeds and feed rates. These models were verified by performing confirmation experiments. The results obtained showed that cold N2+ MQL improved performance in terms of tool life, surface roughness and cutting forces in comparison to dry, cold N2, and N2+MQL conditions. At cutting speed of 100 m/min and feed rate of 0.16 mm/rev, cold N2+MQL condition prolongs the tool life by 135%, decreases the cutting forces by 18%, and improves surface roughness by 19% as compared to dry cutting. Flank and crater were observed at the tool nose. Abrasion and adhesion were the dominant wear mechanisms when turning hardened martensitic stainless steel. The machined surface had less alteration of grain microstructure and higher hardness in cold N2+MQL condition compared to the dry cutting condition. The longest tool life was obtained at low cutting speed and low feed rate, whereas lower cutting forces and better surface roughness were observed at high speed and low feed rate. Analysis based on the mathematical models of machining responses (tool life, surface roughness and cutting forces) would be helpful in selecting cutting variables for optimization of turning hardened stainless steel, which is in line with sustainable and green machining by using cold N2+MQL condition

Fusion of Physiological and Behavioural Signals on SPD Manifolds with Application to Stress and Pain Detection

Existing multimodal stress/pain recognition approaches generally extract features from different modalities independently and thus ignore cross-modality correlations. This paper proposes a novel geometric framework for multimodal stress/pain detection utilizing Symmetric Positive Definite (SPD) matrices as a representation that incorporates the correlation relationship of physiological and behavioural signals from covariance and cross-covariance. Considering the non-linearity of the Riemannian manifold of SPD matrices, well-known machine learning techniques are not suited to classify these matrices. Therefore, a tangent space mapping method is adopted to map the derived SPD matrix sequences to the vector sequences in the tangent space where the LSTM-based network can be applied for classification. The proposed framework has been evaluated on two public multimodal datasets, achieving both the state-of-the-art results for stress and pain detection tasks.Comment: International Conference on Systems, Man, and Cybernetics, IEEE SMC 2022, October 9-12, 202

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Analysis on the Actions of a Continuous Distance Training Session for Teachers and its Impact on Their Actual Practices

Abstrait-Ce travail vise à étudier comment une expérience de formation à distance de trois jours pour enseignants, programmée d'urgence, pour développer chez ces enseignants les capacités d'utilisation de la plateforme numérique, la création et la gestion de ressources numériques, ainsi que la création et la gestion d'un évaluation, afin qu'ils soient en mesure d'assurer correctement la continuité pédagogique. La mise en place de ce mode de formation a été recommandée dans un état d'urgence en raison de la pandémie de Corona Virus qui a été connue dans le monde entier et qui a provoqué la fermeture des écoles, ce qui a forcé le passage du mode présentiel à l'enseignement à distance, au cours de l'année 2020. Cette formation à distance, qui concerne les enseignants des écoles, était nécessaire pour développer leurs capacités à utiliser ce nouveau mode d'enseignement.A partir du cadre de l'évaluation de la formation professionnelle, et à travers les outils de collecte de données construits et utilisés dans cette recherche, les résultats montrent une certaine évolution dans les conceptions de ces enseignants pour revisiter les objectifs de cette formation par les enseignants-formateurs pour son déploiement éventuel

Influence of cutting condition on chip morphology when turning hardened stainless steel using coated carbide cutting tools under minimum quantity of lubrication

The quality of the machined surface is considered as one of the most important characteristics in machining due to the relation between customers' requirements and high performance demands. Machining process, including the resulting surface finish, is significantly influenced by chips generated. Minimum quantity of lubrication (MQL), which sprays small amount of cutting fluid to the cutting zone area with the aid of compressed air, is an ecofriendly cutting fluid application technique with similar advantage to conventional flood cooling. This paper investigates the effect of cutting speed (100 – 170 m/min) and feed rate (0.16 – 0.24 mm/rev)) on chip morphology when turning a hardened AISI 420 stainless steel under MQL using castor oil. Chip forms, thickness, and hardness were observed. It was found that continuous chip was generated at low cutting speed at all feed rates and saw toothed or segmented chips are produced at medium and high cutting speeds and feed rates. Cutting speed and feed rate influenced the thickness of the chip generated

Treatment of heavy petroleum hydrocarbons polluted soil leachates by ultrafiltration and oxidation for surfactant recovery

International audienc

Machinability of Stainless Tool Steel using Nitrogen Oil-Mist coalant

For all dry machining process, temperature generated in the cutting zone is the major challenge. It causes tool failure and results in unsatisfactory surface finish. Application of flood coolant method during machining processes can significantly reduce the temperature and consequently extend the cutting tool life. However, it has serious concerns regarding environmental pollution, operator health and manufacturing cost. These issues are usually attempts to be overcame by using minimum quantity lubrication (MQL) technique. This method merges the advantages of both dry cutting and flood cooling by spraying a small amount of lubricant to the cutting zone using vegetable oil. In this paper, another technique is proposed in order to further enhance the machineability of the stainless tool steel (STAVAX ESR 48 HRC). This involves using of nitrogen gas (N2) and air as cooling medium in combination with oil mist lubricant (MQL). The results show that the combination between nitrogen and oil-mist lubricant much more prolonged the tool life and improved the surface finish than the air-oil mist lubricant medium

Target-Based Virtual Screening of Natural Compounds Identifies a Potent Antimalarial With Selective Falcipain-2 Inhibitory Activity

We employed a comprehensive approach of target-based virtual high-throughput screening to find potential hits from the ZINC database of natural compounds against cysteine proteases falcipain-2 and falcipain-3 (FP2 and FP3). Molecular docking studies showed the initial hits showing high binding affinity and specificity toward FP2 were selected. Furthermore, the enzyme inhibition and surface plasmon resonance assays were performed which resulted in a compound ZINC12900664 (ST72) with potent inhibitory effects on purified FP2. ST72 exhibited strong growth inhibition of chloroquine-sensitive (3D7; EC50 = 2.8 µM) and chloroquine-resistant (RKL-9; EC50 = 6.7 µM) strains of Plasmodium falciparum. Stage-specific inhibition assays revealed a delayed and growth defect during parasite growth and development in parasites treated with ST72. Furthermore, ST72 significantly reduced parasite load and increased host survival in a murine model infected with Plasmodium berghei ANKA. No Evans blue staining in ST72 treatment indicated that ST72 mediated protection of blood–brain barrier integrity in mice infected with P. berghei. ST72 did not show any significant hemolysis or cytotoxicity against human HepG2 cells suggesting a good safety profile. Importantly, ST72 with CQ resulted in improved growth inhibitory activity than individual drugs in both in vitro and in vivo studies