23 research outputs found

    Robot Learning on the Job: Human-in-the-Loop Autonomy and Learning During Deployment

    Full text link
    With the rapid growth of computing powers and recent advances in deep learning, we have witnessed impressive demonstrations of novel robot capabilities in research settings. Nonetheless, these learning systems exhibit brittle generalization and require excessive training data for practical tasks. To harness the capabilities of state-of-the-art robot learning models while embracing their imperfections, we present Sirius, a principled framework for humans and robots to collaborate through a division of work. In this framework, partially autonomous robots are tasked with handling a major portion of decision-making where they work reliably; meanwhile, human operators monitor the process and intervene in challenging situations. Such a human-robot team ensures safe deployments in complex tasks. Further, we introduce a new learning algorithm to improve the policy's performance on the data collected from the task executions. The core idea is re-weighing training samples with approximated human trust and optimizing the policies with weighted behavioral cloning. We evaluate Sirius in simulation and on real hardware, showing that Sirius consistently outperforms baselines over a collection of contact-rich manipulation tasks, achieving an 8% boost in simulation and 27% on real hardware than the state-of-the-art methods, with twice faster convergence and 85% memory size reduction. Videos and code are available at https://ut-austin-rpl.github.io/sirius

    A New Approach for the Preparation of Variable Valence Rare Earth Alloys from Nano Rare Earth Oxides at a Low Temperature in Molten Salt

    Get PDF
    The solubility of RE2O3 (RE = Eu, Sm, and Yb) with variable valence in molten salts is extremely low. It is impossible to directly obtain variable valence metals or alloys from RE2O3 using electrolysis in molten salts. We describe a new approach for the preparation of variable valence rare earth alloys from nano rare earth oxide. The excellent dispersion of nano–Eu2O3 in LiCl–KCl melts was clearly observed using a luminescent feature of Eu3+ as a probe. The ratio of solubility of nano-Sm2O3/common Sm2O3 is 16.98. Electrochemical behavior of RE2O3 on a molybdenum and Al electrode in LiCl–KCl melts containing AlCl3 at 480 °C was investigated by different electrochemical techniques, such as cyclic voltammetry (CV), square wave voltammetry, and chronopotentiometry. Prior to the reduction peak of Al, the reduction peaks of Sm(III)/Sm(II), Yb(III)/Yb(II), and Eu(III)/Eu(II) were observed at about −0.85, −0.45, and 0.39 V insquare wave voltammetry, respectively. The underpotential deposition of RE on pre-deposited aluminum leads to the formation of Al–RE alloy. The structure, morphology, and energy dispersion analysis of the deposit obtained by potentiostatic electrolysis are analyzed. Al2Sm and Al3Sm alloys were successfully obtained from nano–Sm2O3

    The G-Protein-Coupled Chemoattractant Receptor Fpr2 Exacerbates High Glucose-Mediated Proinflammatory Responses of Müller Glial Cells

    No full text
    In proliferative diabetic retinopathy (PDR), activated Müller glial cells (MGCs) exhibit increased motility and a fibroblast-like proliferation phenotype that contribute to the formation of fibrovascular membrane. In this study, we investigated the capacity of high glucose (HG) to regulate the expression of cell surface receptors that may participate in the proinflammatory responses of MGCs. We found that MGCs express a G-protein coupled chemoattractant receptor formyl peptide receptor 2 (Fpr2) and fibroblast growth factor receptor 1 (FGFR1), which mediated MGC migration and proliferation in response to corresponding ligands. HG upregulated Fpr2 through an NF-κB pathway in MGCs, increased the activation of MAPKs coupled to Fpr2 and FGFR1, which also further enhanced the production of vascular endothelial growth factor by MGCs in the presence of HG. In vivo, Fpr2 was more highly expressed by retina MGCs of diabetic mice and the human counterpart FPR2 was detected in the retina MGCs in fibrovascular membrane of PDR patients. To support the potential pathological relevance of Fpr2, an endogenous Fpr2 agonist cathelin-related antimicrobial peptide was detected in mouse MGCs and the retina, which was upregulated by HG. These results suggest that Fpr2, together with FGFR1, may actively participate in the pathogenesis of PDR thus may be considered as one of the potential therapeutic targets

    EGFR/BRAF/MEK co-inhibition for EGFR-mutated lung adenocarcinoma patients with an acquired BRAFV600E mutation: a case report and review of literature

    No full text
    Despite the promising initial anti-tumor efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), most advanced non-small-cell lung cancers (NSCLCs) progress eventually due to therapeutic resistance. V-Raf murine sarcoma viral oncogene homolog B1 (BRAF)V600E mutation has been considered as an uncommon mutation that contributes to acquired resistance for EGFR-TKIs. In the presented case, BRAFV600E mutation was detected as an acquired resistance-mediated mutation in a patient treated with osimertinib (a third-generation EGFR-TKI). The presented patient achieved partial regression and ongoing PFS of four months after the co-inhibition of osimertinib plus dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor). Our case further enriches the clinical evidence of the efficacy of EGFR/BRAF/MEK co-inhibition in patients with an acquired BRAFV600E mutation, consistent with the review of the literature (eight cases). Additionally, our case highlights the important role of sample type, method, and platform of gene detection in patient management, life quality, and prognosis, as well as the understanding of acquired resistance mechanism

    Three-Dimensional Broadband Electric Field Sensor Based on Integrated Lithium Niobate on Insulator

    No full text
    A three-dimensional (3D) electric field sensing scheme is proposed and experimentally demonstrated based on an integrated lithium niobate on insulator (LNOI) platform. The 3D measurement is realized by packing three LNOI-based sensor chips in a triangular-prism-type clamp. For each sensor chip, the optical waveguide has an asymmetrical Michelson interferometer architecture, and the tapered dipole antenna is inclined to the optical waveguide. By finely placing the three sensor chips in the clamp, the three pairs of inclined tapered dipole antennas are mutually orthogonal and can be applied to measure the electric field in three orthogonal polarization directions. The volume of the packaged 3D sensor is 9.5 cm3. In the experiment, a flat response in the frequency range of 10 MHz to 3 GHz is demonstrated. In addition, a 3 × 3 response calibration matrix is obtained and utilized to reduce the measurement error. After calibration, the relative measurement error of the electric field amplitude is smaller than 5.1% for every polarization direction

    Broadband Signal Digitization Based on Low-Speed Non-Uniform Photonic Sampling

    No full text
    A new non-uniform photonic sampling (NPS) strategy and its special signal reconstruction algorithm are proposed to achieve digital acquisition of broadband periodic signals at a low sampling rate. Compared with the existing schemes, the NPS strategy can largely reduce the sampling number to acquire identical signal information as that obtained by using its equivalent high-speed uniform photonic sampling, which is beneficial for reducing the sampling time and the data volume of the NPS-based analog-to-digital converter (ADC). In addition, the calculation time of the proposed algorithm is millions of times lower than that of the digital alias-free signal processing (DASP) algorithm used before, which benefits from the fast Fourier transform calculation of a one-dimensional data array instead of a two-dimensional data array calculation in the DASP algorithm. A simulation is performed to validate the feasibility of the proposed scheme. In the simulation, a single-channel NPS-based ADC with an average sampling rate of 1 GSa/s is demonstrated by using the proposed NPS strategy and signal reconstruction algorithm. The results indicate the reconstructed signal information for a single-tone microwave signal at 9.9 GHz and a linear frequency modulation signal in the frequency range of 1 GHz to 9 GHz are identical to those obtained by using its equivalent high-speed uniform photonic sampling-based ADC with a sampling rate of 20 GSa/s

    Emerging trends in the coexistence of primary lung Cancer and hematologic malignancy: a comprehensive analysis of clinicopathological features and genetic abnormalities

    No full text
    Abstract Background The incidence of multiple primary cancers (MPC), especially involving primary lung cancer (PLC) and primary hematologic malignancies (PHM), is rising. This study aims to analyze clinicopathological features, gene abnormalities, and prognostic outcomes in individuals diagnosed with PLC-PHM MPC. Methods A retrospective analysis included 89 patients diagnosed with PLC-PHM MPC at the Respiratory or Hematology Departments of Ruijin Hospital from 2003 to 2022 (a total of 842,047 people). Next-generation sequencing (NGS) assessed lung cancer specimens, while Polymerase Chain Reaction (PCR) and NGS were used for hematologic malignancy specimens. Statistical analysis involved survival analysis and Cox regression. Results PLC-PHM MPC incidence surged from 1.67 per year (2011–2013) to 16.3 per year (2020–2022). The primary demographic for PLC-PHM MPC consists predominantly of elderly (average age 66 years) males (59.6%), with a high prevalence of metachronous MPC (89.9%). The prevailing histological types were lung adenocarcinoma (70.8%) in lung cancer (LC) and mature B-cell lymphomas (50.6%) in hematologic malignancies (HM). Notably, in a molecular testing cohort of 38 LC patients, 84.2% of lung cancer cases exhibited driver mutations, in which EGFR mutations frequence prevalent was 74.2%. In total group of 85 cases achieved a median overall survival (mOS) of 46.2 months, with a 5-year survival rate of 37.9% and advanced LC patients with LC gene mutations achieved a mOS was 52.6 months, with a 5-year OS rate of 30.6%. The median progression-free survival (PFS) following first-line treatment of 11 advanced patients with lung cancer-associated driver gene mutations is 26.6 months. Multivariate Cox regression revealed a favorable OS associated with surgery for LC, favorable PS score, adenocarcinoma pathology of LC, and the presence of genetic abnormalities associated with HM. Conclusion PLC-PHM MPC incidence is rising, characterized by a significant proportion of lung adenocarcinoma and a high prevalence of positive driver genes, especially in EGFR. Despite suffering from two primary tumors, the PLC-PHM MPC patients had superior data of both PFS and OS, suggesting an inherently intricate background of genetic abnormalities between the two kinds of tumors
    corecore