Distributed Event-Triggered Online Learning for Multi-Agent System Control using Gaussian Process Regression

For the cooperative control of multi-agent systems with unknown dynamics, data-driven methods are commonly employed to infer models from the collected data. Due to the flexibility to model nonlinear functions and the existence of theoretical prediction error bound, Gaussian process (GP) regression is widely used in such control problems. Online learning, i.e. adding newly collected training data to the GP models, promises to improve control performance via improved predictions during the operation. In this paper, we propose a distributed event-triggered online learning algorithm for multi-agent system control. The proposed algorithm only employs locally available information from the neighbors and achieves a guaranteed overall control performance with desired tracking error bound. Moreover, the exclusion of the Zeno behavior for each agent is proved. Finally, the effectiveness of the proposed event-triggered online learning is demonstrated in simulations

The Application of OCTA in Assessment of Anti-VEGF Therapy for Idiopathic Choroidal Neovascularization

Purpose. To assess the morphology of idiopathic choroidal neovascularization (ICNV) by optical coherence tomography angiography (OCTA) and determine the therapeutic effects of intravitreal antivascular endothelial growth factor (anti-VEGF). Method. Patients with naive ICNV were assessed by spectral domain optical coherence tomography (SD-OCT) and OCTA in this observational study. The timing of observation was before treatment, 1 day after treatment with intravitreal anti-VEGF injection, and 1 month after the treatment. The central retina thickness (CRT) on SD-OCT, selected CNV area, and flow area on OCTA were measured. Results. A total of 17 eyes from 17 patients with ICNV were included in this study. OCTA showed visible irregular choroidal neovascularization with “tree-in-bud” form on outer retinal layer. After treatment, as well as in the 1-day follow-up, CNV decreased in size from the periphery, and the vessel density was reduced. As shown on OCTA, the selected CNV area and flow area were significantly reduced compared to pretreatment. The rate of CNV vessel area changes was higher on OCTA than the changes in CRT on SD-OCT at 1-day and 1-month follow-up. Conclusion. Intravitreal injection of anti-VEGF is effective for idiopathic choroidal neovascularization, and the treatment outcomes are observable after 1 day. OCTA provides a useful approach for monitoring and evaluating the treatment of intravitreal anti-VEGF for CNV

Large Eddy Simulation (LES) of Glass Fibre Dispersion in an Internally Spout-Fluidised Bed for Thermoplastic Composite Processing

Large eddy simulation (LES) has been conducted to investigate glass fibre dispersion in an internally spout-fluidised bed with draft tube and disk-baffle, which was used in the manufacture of long glass fibre reinforced thermoplastic composites. The LES results have demonstrated that the internally spout-fluidised bed with draft tube and disk-baffle can remarkably improve its hydrody-namic behaviour, which can effectively disperse fibre bundles and promote pre-impregnation with resin powder in manufacturing fibre reinforced thermoplastics. The hydrodynamics of the spout-fluidised bed has been investigated and reported in a previous paper (Hosseini et al., 2009). This study attempts to reveal important features of fibre dispersion and correlations between the fibre disper-sion and the characteristics of turbulence in the internally spout-fluidised bed using the LES modelling, focusing on the likely hydro-dynamic impact on fibre dispersion. The simulation has clearly indicated that there exists a strong interaction between the turbulent shear flow and transported fibres in the spout-fluidised bed. Fibre entrainment is strongly correlated with the local vorticity distribu-tion. The dispersion of fibres was modelled by a species transport equation in the LES simulation. The turbulent kinetic energy, Rey-nolds stress and strain rate were obtained by statistical analysis of the LES results. The LES results also clearly show that addition of the internals in the spout-fluidised bed can significantly change the turbulent flow features and local vorticity distribution, enhancing the capacity and efficiency of fibre flocs dispersion

Semi-automated Thermal Envelope Model Setup for Adaptive Model Predictive Control with Event-triggered System Identification

To reach carbon neutrality in the middle of this century, smart controls for building energy systems are urgently required. Model predictive control (MPC) demonstrates great potential in improving the performance of heating ventilation and air-conditioning (HVAC) systems, whereas its wide application in the building sector is impeded by the considerable manual efforts involved in setting up the control-oriented model. To facilitate the system identification (SI) of the building envelope as well as the configuration of the MPC algorithms with less human intervention, a semantic-assisted control framework is proposed in this paper. We first integrate different data sources required by the MPC algorithms such as the building topology, HVAC systems, sensor data stream and control settings in the form of a knowledge graph and then employ the data to set up the MPC algorithm automatically. Moreover, an event-triggered SI scheme is designed, to ensure the computational efficiency and accuracy of the MPC algorithm simultaneously. The proposed method is validated via simulations. The results demonstrate the practical relevance and effectiveness of the proposed semantics-assisted MPC framework with event-triggered learning of system dynamics

catena-Poly[[aqua­(3-methyl­benzoato-κ2 O,O′)lead(II)]-μ-3-methyl­benzoato-κ4 O:O,O′:O′]

The reaction of lead(II) acetate and 3-methyl­benzoic acid (MBA) in aqueous solution yielded the title polymer, [Pb(C8H7O2)2(H2O)]n. The asymmetric unit contains two PbII atoms, four MBA ligands and two water mol­ecules. Each PbII cation is hepta­coordinated and chelated by four carboxyl­ate O atoms from two MBA ligands. The Pb atoms are bridged through the carboxyl­ate O atoms from another two MBA ligands, leading to a central Pb2O2 core. The Pb—O bond lengths are in the range 2.325 (3)–2.757 (4) Å. The intra- and inter­dimer Pb⋯Pb distances are 4.2942 (3) and 4.2283 (3) Å, respectively, indicating little direct metal–metal inter­action. The coordinating water mol­ecules and carboxyl­ate O atoms are involved in extensive O—H⋯O hydrogen-bonding inter­actions. The complex has an extended ladder-like chain structure and the chains are assembled by hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.6246 (3) Å] into a three-dimensional supra­molecular structure

Growth of Human Colorectal Cancer SW1116 Cells Is Inhibited by Cytokine-Induced Killer Cells

Previous reports have suggested that treatment with cytokine-induced killer (CIK) cells may benefit patients with various types of tumor. The aim of this study was to evaluate the antitumor effects of CIK cells against the colorectal cancer line SW1116 in vitro and in vivo. CIK cells were generated routinely from peripheral blood mononuclear cells of healthy human donors, and the number of CD3+CD56+ cells was expanded more than 1300-fold after 14-day culture. At an effector : target cell ratio of 50 : 1, the percentage lysis of SW1116 cells reached 68% in the presence of CIK cells, Experimental mice injected with SW1116 cells subcutaneously were divided randomly into four groups: untreated, 5-fluorouracil (5-FU)-treated, CIK-consecutive treated (injected once/day) and CIK-interval treated (injected once every 5 days). CIK cells were injected abdominally five times in total. Compared with the untreated group, xenograft growth was inhibited greatly by CIK treatment, to nearly the same extent as with 5-FU treatment. We demonstrated that the necrotic area in the tumor xenograft was markedly larger in the CIK-treated groups than in the other groups. These findings suggest that CIK-based immunotherapy may represent an effective choice for patients with colorectal cancer

Fast IMU-based Dual Estimation of Human Motion and Kinematic Parameters via Progressive In-Network Computing

Many applications involve humans in the loop, where continuous and accurate human motion monitoring provides valuable information for safe and intuitive human-machine interaction. Portable devices such as inertial measurement units (IMUs) are applicable to monitor human motions, while in practice often limited computational power is available locally. The human motion in task space coordinates requires not only the human joint motion but also the nonlinear coordinate transformation depending on the parameters such as human limb length. In most applications, measuring these kinematics parameters for each individual requires undesirably high effort. Therefore, it is desirable to estimate both, the human motion and kinematic parameters from IMUs. In this work, we propose a novel computational framework for dual estimation in real-time exploiting in-network computational resources. We adopt the concept of field Kalman filtering, where the dual estimation problem is decomposed into a fast state estimation process and a computationally expensive parameter estimation process. In order to further accelerate the convergence, the parameter estimation is progressively computed on multiple networked computational nodes. The superiority of our proposed method is demonstrated by a simulation of a human arm, where the estimation accuracy is shown to converge faster than with conventional approaches

Effects of Intravitreal Ranibizumab Injection on Chinese Patients with Wet Age-Related Macular Degeneration: 5-Year Follow-Up Results

Purpose. To observe the effect of intravitreal ranibizumab injection on wet age-related macular degeneration (wAMD) over 5 years in Chinese patients. Methods. Thirty-seven patients who were diagnosed with wAMD in our hospital from June 2007 to June 2014 were retrospectively reviewed. The PRN regimen and the treatment and extend regimen were applied. Best corrected visual acuity (BCVA), number of ranibizumab injections, and changes in the choroidal neovascularization (CNV) lesion over 5 years were analyzed. Results. The mean BCVA measured by the ETDRS chart at baseline was 47.4 and 5 years after the treatment it was 34.89 letters, which was significantly different (p=0.013). Fourteen eyes (37.8%) had improved visual acuity after 5 years. The number of injections in 5 years was 11.53, and most of the injections were in the first two years. Seventeen (45.9%) cases developed fibrous lesions, and 2 (5.4%) cases had atrophic lesions after 5 years. The fibrosis/atrophy was significantly correlated with the injection numbers (Pearson, r=0.663, and p=0.000). Conclusion. Most of the patients can maintain visual acuity treated by ranibizumab in the first 3 years. After 5 years, some patients can still improve or maintain visual acuity. Fibrous scarring of the lesion is the main reason for a decrease in vision of wAMD patients