324 research outputs found
Self-adjustable domain adaptation in personalized ECG monitoring integrated with IR-UWB radar
To enhance electrocardiogram (ECG) monitoring systems in personalized detections, deep neural networks (DNNs) are applied to overcome individual differences by periodical retraining. As introduced previously [4], DNNs relieve individual differences by fusing ECG with impulse radio ultra-wide band (IR-UWB) radar. However, such DNN-based ECG monitoring system tends to overfit into personal small datasets and is difficult to generalize to newly collected unlabeled data. This paper proposes a self-adjustable domain adaptation (SADA) strategy to prevent from overfitting and exploit unlabeled data. Firstly, this paper enlarges the database of ECG and radar data with actual records acquired from 28 testers and expanded by the data augmentation. Secondly, to utilize unlabeled data, SADA combines self organizing maps with the transfer learning in predicting labels. Thirdly, SADA integrates the one-class classification with domain adaptation algorithms to reduce overfitting. Based on our enlarged database and standard databases, a large dataset of 73200 records and a small one of 1849 records are built up to verify our proposal. Results show SADA\u27s effectiveness in predicting labels and increments in the sensitivity of DNNs by 14.4% compared with existing domain adaptation algorithms
Revealing spatio-spectral electroencephalographic dynamics of musical mode and tempo perception by independent component analysis.
BackgroundMusic conveys emotion by manipulating musical structures, particularly musical mode- and tempo-impact. The neural correlates of musical mode and tempo perception revealed by electroencephalography (EEG) have not been adequately addressed in the literature.MethodThis study used independent component analysis (ICA) to systematically assess spatio-spectral EEG dynamics associated with the changes of musical mode and tempo.ResultsEmpirical results showed that music with major mode augmented delta-band activity over the right sensorimotor cortex, suppressed theta activity over the superior parietal cortex, and moderately suppressed beta activity over the medial frontal cortex, compared to minor-mode music, whereas fast-tempo music engaged significant alpha suppression over the right sensorimotor cortex.ConclusionThe resultant EEG brain sources were comparable with previous studies obtained by other neuroimaging modalities, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET). In conjunction with advanced dry and mobile EEG technology, the EEG results might facilitate the translation from laboratory-oriented research to real-life applications for music therapy, training and entertainment in naturalistic environments
An experimental study on the effect of salt spray testing on the optical properties of solar selective absorber coatings produced with different manufacturing technologies
Solar selective absorber coating (SSAC) is one of the key components of a solar collector, with its optical properties having a significant impact on the collector’s thermal performance. The key parameters characterizing the optical properties of an SSAC are the solar absorptance (absorptance of solar radiation) and the thermal emittance (emittance for long-wave radiation). However, some of high-performing SSACs suffer from some drawbacks, such as lower durability, lower resistance to corrosion and abrasion, which is particularly harmful for SSACs, as, for example, chlorides in the atmosphere have become a main contributor to corrosion in coastal areas with the increasing trend of global warming. In this paper, salt spray tests have been conducted on the SSACs manufactured by three common manufacturing technologies, i.e., the anode oxidation
(AO) technology, the vacuum magnetron sputtering (VMS) technology, and the black chromium plating (BCP) technology, over the testing durations of 12 h, 24 h, 36 h, and 48 h, respectively, to examine the effect of the salt spray testing on the optical properties of SSACs manufactured by different manufacturing technologies. The salt spray testing is an accelerated aging testing method for evaluating the SSAC’s resistance to corrosion when it is under an extended exposure to a saline, or salted, spray (fog). The experimental results show that, in general, the SSACs manufactured by the BCP technology have excellent resistance to salt spray (i.e., to corrosion) and those manufactured by the AO technology have only reasonable
resistance to corrosion, whereas the SSACs manufactured by the VMS technology have very poor resistance to corrosion.
The results also demonstrate that there are noticeable differences in the optical properties of the SSAC samples even manufactured by the same technology but by different manufacturers, with some having significant differences. The causes for the differences have been further examined through the inspection of the physical appearance of the selected SSAC samples and the experimentally measured distributions of the monochromatic reflectance of solar radiation of the samples over the solar spectrum before and after the salt spray testing over different durations
Percutaneous Nephrolithotomy under Local Infiltration Anesthesia in Kneeling Prone Position for a Patient with Spinal Deformity
Urolithiasis, a common condition in patients with spinal deformity, poses a challenge to surgical procedures and anesthetic management. A 51-year-old Chinese male presented with bilateral complex renal calculi. He was also affected by severe kyphosis deformity and spinal stiffness due to ankylosing spondylitis. Dr. Li performed the percutaneous nephrolithotomy under local infiltration anesthesia with the patient in a kneeling prone position, achieving satisfactory stone clearance with no severe complications. We found this protocol safe and effective to manage kidney stones in patients with spinal deformity. Local infiltration anesthesia may benefit patients for whom epidural anesthesia and intubation anesthesia are difficult
A Novel Prognostic Predictor of Immune Micro-environment and Therapeutic Response in Kidney Renal Clear Cell Carcinoma based on Necroptosis-related Gene Signature
Background: Necroptosis, a cell death of caspase-independence, plays a pivotal role in cancer biological regulation. Although necroptosis is closely associated with oncogenesis, cancer metastasis, and immunity, there remains a lack of studies determining the role of necroptosis-related genes (NRGs) in the highly immunogenic cancer type, kidney renal clear cell carcinoma (KIRC). Methods: The information of clinicopathology and transcriptome was extracted from TCGA database. Following the division into the train and test cohorts, a three-NRGs (TLR3, FASLG, ZBP1) risk model was identified in train cohort by LASSO regression. The overall survival (OS) comparison was conducted between different risk groups through Kaplan-Meier analysis, which was further validated in test cohort. The Cox proportional hazards regression model was introduced to assess its impact of clinicopathological factors and risk score on survival. ESTIMATE and CIBERSORT algorithms were introduced to evaluate immune microenvironment, while enrichment analysis was conducted to explore the biological significance. Correlation analysis was applied for the correlation assessment between checkpoint gene expression and risk score, between gene expression and therapeutic response. Gene expressions from TCGA were verified by GEO datasets and immunohistochemistry (IHC) analysis. Results: This NRGs-related signature predicted poorer OS in high-risk group, which was also verified in test cohort. Risk score could also independently predict survival outcome of KIRC. Significant changes were also found in immune microenvironment and checkpoint gene expressions between different risk groups, with immune functional enrichment in high-risk group. Interestingly, therapeutic response was correlated with the expressions of NRGs. The expressions of NRGs from TCGA were consistent with those from GEO datasets and IHC analysis. Conclusion: The NRGs-related signature functions as a novel prognostic predictor of immune microenvironment and therapeutic response in KIRC
HEAR: Approach for Heartbeat Monitoring with Body Movement Compensation by IR-UWB Radar
Further applications of impulse radio ultra-wideband radar in mobile health are hindered by the difficulty in extracting such vital signals as heartbeats from moving targets. Although the empirical mode decomposition based method is applied in recovering waveforms of heartbeats and estimating heart rates, the instantaneous heart rate is not achievable. This paper proposes a Heartbeat Estimation And Recovery (HEAR) approach to expand the application to mobile scenarios and extract instantaneous heartbeats. Firstly, the HEAR approach acquires vital signals by mapping maximum echo amplitudes to the fast time delay and compensating large body movements. Secondly, HEAR adopts the variational nonlinear chirp mode decomposition in extracting instantaneous frequencies of heartbeats. Thirdly, HEAR extends the clutter removal method based on the wavelet decomposition with a two-parameter exponential threshold. Compared to heart rates simultaneously collected by electrocardiograms (ECG), HEAR achieves a minimum error rate 4.6% in moving state and 2.25% in resting state. The Bland–Altman analysis verifies the consistency of beat-to-beat intervals in ECG and extracted heartbeat signals with the mean deviation smaller than 0.1 s. It indicates that HEAR is practical in offering clinical diagnoses such as the heart rate variability analysis in mobile monitoring
Experimental and numerical studies on indoor thermal comfort in fluid flow: a case study on primary school classrooms
Indoor thermal comfort in primary classrooms is important to students' learning and health. The studies focusing on it, especially under the subtropical plateau monsoon climate, are scarce. In this study, the indoor thermal comfort surveys and parameter measurements were made over the period from October 2018 to December 2018 in Kunming, China. A series of indoor thermal comfort and outdoor parameters were measured each 1 h and subjective questionnaire surveys were performed on the selected 20 students every week except on holidays. A series of three-dimensional numerical simulations were carried out using ANSYS Fluent
Sunlight penetration dominates the thermal regime and energetics of a shallow ice-covered lake in arid climate
The Mongolian Plateau is characterized by cold and arid winters with very little precipitation (snowfall), strong solar insolation, and dry air, but little is known about the thermal regimes of the ice and ice-covered lakes and their response to the distinct weather and climate in this region. In a typical large, shallow lake, ice and snow processes (cover) and under-ice thermodynamics were monitored for four winters in 2015-2019. Heat transfer at the ice-water interface and lake heat budget were investigated. The results revealed that persistent bare ice of 35-50 cm thickness transmits 20 %-35 % of the incident solar radiation into the water below. This is a dominant source for under-ice energy flows and causes/maintains high water temperature (up to 6-8 degrees C) and high heat flux from water to ice (averages of 20-45 W m(-2)) in mid-winter, as well as higher heat conduction in the ice interior during freezing. The heat balance shows that the transmitted radiation and the heat flux from water to ice are the dominant and highly correlated heat flows in the lake. Both bulk water temperature and temperature structure are sensitive to solar transmittance and occasional snow events. Under-ice convective mixing does not necessarily occur because of stratification of salinity in the water body. In particular, salt exclusion during freezing changes both the bulk salinity and the salinity profile, which plays a major role in the stability and mixing of the water column in this shallow lake.Peer reviewe
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