MixRL: Data Mixing Augmentation for Regression using Reinforcement Learning

Data augmentation is becoming essential for improving regression accuracy in critical applications including manufacturing and finance. Existing techniques for data augmentation largely focus on classification tasks and do not readily apply to regression tasks. In particular, the recent Mixup techniques for classification rely on the key assumption that linearity holds among training examples, which is reasonable if the label space is discrete, but has limitations when the label space is continuous as in regression. We show that mixing examples that either have a large data or label distance may have an increasingly-negative effect on model performance. Hence, we use the stricter assumption that linearity only holds within certain data or label distances for regression where the degree may vary by each example. We then propose MixRL, a data augmentation meta learning framework for regression that learns for each example how many nearest neighbors it should be mixed with for the best model performance using a small validation set. MixRL achieves these objectives using Monte Carlo policy gradient reinforcement learning. Our experiments conducted both on synthetic and real datasets show that MixRL significantly outperforms state-of-the-art data augmentation baselines. MixRL can also be integrated with other classification Mixup techniques for better results.Comment: 15 pages, 9 figures, 7 table

Phase Current Measurement Method of Dual Inverter-Motor Drive System Using a Single DC Link Current Sensor

In recent years, electric propulsion systems have become widely, used and these systems have strict limits in volume and weight. Therefore, it is necessary to reduce the weight of the inverter-motor drive system. In a typical n inverter-motor drive system, at least 2n phase current sensors are required. In order to reduce the number of phase current sensors, this paper proposes a method for measuring phase current using n DC link current sensors in a 2n inverter-motor drive system. Two phase currents per inverter-motor system are measured during one period of the switching frequency using the pulse width modulation (PWM) shift method. However, since the measured phase current contains an error component in the average current, the error component was compensated for in order to obtain a current similar to the actual phase current by using the slope and dwell time of the phase current. The effectiveness of the proposed method is verified through experiments

Dual Fistulas of Ascending Aorta and Coronary Artery to Pulmonary Artery

Coronary artery fistula to pulmonary artery is common. However, to the best of our knowledge, a case of coronary artery fistula to pulmonary artery associated with aortopulmonary fistula remains unreported. We herein report a 64-year-old female with a left anterior descending coronary artery and ascending aorta to pulmonary artery fistulas, and conduct a brief review of the literature

Dectin-1 signaling coordinates innate and adaptive immunity for potent host defense against viral infection

BackgroundMost commercial foot-and-mouth disease (FMD) vaccines have various disadvantages, such as low antibody titers, short-lived effects, compromised host defense, and questionable safety.ObjectivesTo address these shortcomings, we present a novel FMD vaccine containing Dectin-1 agonist, β-D-glucan, as an immunomodulatory adjuvant. The proposed vaccine was developed to effectively coordinate innate and adaptive immunity for potent host defense against viral infection.MethodsWe demonstrated β-D-glucan mediated innate and adaptive immune responses in mice and pigs in vitro and in vivo. The expressions of pattern recognition receptors, cytokines, transcription factors, and co-stimulatory molecules were promoted via FMD vaccine containing β-D-glucan.Resultsβ-D-glucan elicited a robust cellular immune response and early, mid-, and long-term immunity. Moreover, it exhibited potent host defense by modulating host’s innate and adaptive immunity.ConclusionOur study provides a promising approach to overcoming the limitations of conventional FMD vaccines. Based on the proposed vaccine’s safety and efficacy, it represents a breakthrough among next-generation FMD vaccines

Lung function, coronary artery calcification, and metabolic syndrome in 4905 Korean males

SummaryBackgroundImpaired lung function is an independent predictor of cardiovascular mortality. We assessed the relationships of lung function with insulin resistance (IR), metabolic syndrome (MetS), systemic inflammation and coronary artery calcification score (CACS) measured by computed tomography (CT) scan an indicator of coronary atherosclerosis.MethodsWe identified 4905 adult male patients of the Health Promotion Center in Samsung Medical Center between March 2005 and February 2008 and retrospectively reviewed the following data for these patients: pulmonary function, CT-measured CACS, anthropometric measurement, fasting glucose, insulin, lipid profiles, serum C-reactive protein (CRP) and homeostatic model assessment (HOMA-IR). MetS was defined according to the AHA/NHLBI criteria.ResultsWhen the subjects were divided into four groups according to quartiles of FVC or FEV1 (% pred), serum CRP level, HOMA-IR, prevalence of MetS and CACS significantly increased as the FVC or FEV1 (% pred) decreased. The odds ratios (ORs) for MetS in the lowest quartiles of FVC and FEV1 (% pred) were 1.85 (95% CI, 1.49–2.30; p<0.001) and 1.47 (95% CI, 1.20–1.81; p<0.001) respectively. The ORs for the presence of coronary artery calcification in the lowest quartiles of FVC and FEV1 (% pred) were 1.31 (95% CI, 1.09–1.58; p=0.004) and 1.22 (95% CI, 1.02–1.46; p=0.029) respectively. Obesity, CRP, HOMA-IR, and the presence of coronary artery calcium were independent risk predictors for impaired lung function.ConclusionMetabolic syndrome, insulin resistance, coronary atherosclerosis, and systemic inflammation are closely related to the impaired lung function

Applications of Bioinspired Reversible Dry and Wet Adhesives: A Review

&lt;jats:p&gt;Bioinspired adhesives that emulate the unique dry and wet adhesion mechanisms of living systems have been actively explored over the past two decades. Synthetic bioinspired adhesives that have recently been developed exhibit versatile smart adhesion capabilities, including controllable adhesion strength, active adhesion control, no residue remaining on the surface, and robust and reversible adhesion to diverse dry and wet surfaces. Owing to these advantages, bioinspired adhesives have been applied to various engineering domains. This review summarizes recent efforts that have been undertaken in the application of synthetic dry and wet adhesives, mainly focusing on grippers, robots, and wearable sensors. Moreover, future directions and challenges toward the next generation of bioinspired adhesives for advanced industrial applications are described.&lt;/jats:p&gt

Urine myo-inositol as a novel prognostic biomarker for diabetic kidney disease: a targeted metabolomics study using nuclear magnetic resonance

Background As a leading cause of chronic kidney disease, clinical demand for noninvasive biomarkers of diabetic kidney disease (DKD) beyond proteinuria is increasing. Metabolomics is a popular method to identify mechanisms and biomarkers. We investigated urinary targeted metabolomics in DKD patients. Methods We conducted a targeted metabolomics study of 26 urinary metabolites in consecutive patients with DKD stage 1 to 5 (n = 208) and healthy controls (n = 26). The relationships between estimated glomerular filtration rate (eGFR) or urine protein-creatinine ratio (UPCR) and metabolites were evaluated. Multivariate Cox analysis was used to estimate relationships between urinary metabolites and the target outcome, end-stage renal disease (ESRD). C statistics and time-dependent receiver operating characteristics (ROC) were used to assess diagnostic validity. Results During a median 4.5 years of follow-up, 103 patients (44.0%) progressed to ESRD and 65 (27.8%) died. The median fold changes of nine metabolites belonged to monosaccharide and tricarboxylic acid (TCA) cycle metabolites tended to increase with DKD stage. Myo-inositol, choline, and citrates were correlated with eGFR and choline, while mannose and myo-inositol were correlated with UPCR. Elevated urinary monosaccharide and TCA cycle metabolites showed associations with increased morality and ESRD progression. The predictive power of ESRD progression was high, in the order of choline, myo-inositol, and citrate. Although urinary metabolites alone were less predictive than serum creatinine or UPCR, myo-inositol had additive effect with serum creatinine and UPCR. In time-dependent ROC, myo-inositol was more predictive than UPCR of 1-year ESRD progression prediction. Conclusion Myo-inositol can be used as an additive biomarker of ESRD progression in DKD

Clinical application of the Panbio™ COVID-19 Ag rapid test device and SSf-COVID19 kit for the detection of SARS-CoV-2 infection

Objective We evaluated the sensitivity and specificity of the Panbio™ COVID-19 Ag rapid test device using nasal swabs and those of the SSf-COVID19 kit, one of RT-PCR tests, using saliva specimens. These tests were compared with RT-PCR tests using nasopharyngeal swabs for the diagnosis of SARS-CoV-2 infection. The three diagnostic tests were simultaneously conducted for patients aged ≥ 18 years, who were about to be hospitalized or had been admitted for COVID-19 confirmed by RT-PCR in two research hospitals from August 20 to October 29, 2021. Nasal swabs were tested using the Panbio™ COVID-19 Ag rapid test device. More than 1 mL of saliva was self-collected and tested using the SSf-COVID19 kit. Results In total, 157 patients were investigated; 124 patients who were about to be hospitalized and 33 patients already admitted for COVID-19. The overall sensitivity and specificity of the Panbio™ COVID-19 Ag rapid test device with nasal swabs were 64.7% (95% confidence interval [CI] 47.9–78.5%) and 100.0% (95% CI 97.0–100.0%), respectively. The median time to confirm a positive result was 180 s (interquartile range 60–255 s). The overall sensitivity and specificity of the SSf-COVID19 kit with saliva specimens were 94.1% (95% CI 80.9–98.4%) and 100.0% (95% CI 97.0–100.0%), respectively.This work was supported by a grant from research fund of Seoul National University Hospital (Grant No. 2021–3148