Weighted optimization-based distributed Kalman filter for nonlinear target tracking in collaborative sensor networks

The identification of the nonlinearity and coupling is crucial in nonlinear target tracking problem in collaborative sensor networks. According to the adaptive Kalman filtering (KF) method, the nonlinearity and coupling can be regarded as the model noise covariance, and estimated by minimizing the innovation or residual errors of the states. However, the method requires large time window of data to achieve reliable covariance measurement, making it impractical for nonlinear systems which are rapidly changing. To deal with the problem, a weighted optimization-based distributed KF algorithm (WODKF) is proposed in this paper. The algorithm enlarges the data size of each sensor by the received measurements and state estimates from its connected sensors instead of the time window. A new cost function is set as the weighted sum of the bias and oscillation of the state to estimate the “best” estimate of the model noise covariance. The bias and oscillation of the state of each sensor are estimated by polynomial fitting a time window of state estimates and measurements of the sensor and its neighbors weighted by the measurement noise covariance. The best estimate of the model noise covariance is computed by minimizing the weighted cost function using the exhaustive method. The sensor selection method is in addition to the algorithm to decrease the computation load of the filter and increase the scalability of the sensor network. The existence, suboptimality and stability analysis of the algorithm are given. The local probability data association method is used in the proposed algorithm for the multitarget tracking case. The algorithm is demonstrated in simulations on tracking examples for a random signal, one nonlinear target, and four nonlinear targets. Results show the feasibility and superiority of WODKF against other filtering algorithms for a large class of systems

Enhancing the Hg(II) Removal Efficiency from Real Wastewater by Novel Thymine-Grafted Reduced Graphene Oxide Complexes

In this study, the reduced graphene oxide was modified by grafting thymine on its surface. The resultant reduced graphene oxide-thymine composite (rGO-Thy) exhibits a higher Hg­(II) adsorption capacity and selectivity compared with rGO as the functional group of thymine shows a strong affinity toward Hg­(II) and forms the thymine-Hg­(II)-thymine complex. The relative selectivity coefficients of rGO-Thy for Hg­(II)/Pb­(II), Hg (II)/Ni­(II), Hg (II)/Co­(II), Hg (II)/Cu­(II), and Hg­(II)/Cd­(II) are 21.72, 7.08, 5.37, 4.37, and 10.51, respectively. This is mainly attributed to the thymine-specific binding with Hg­(II). In addition, the adsorption capacity of rGO-Thy for Hg­(II) is almost 2 times higher than reduced graphene oxide (rGO). Kinetics studies indicate that the adsorption process fits well with the pseudo-second-order model, and the adsorption kinetic constant is 0.02 g·mg^–1·min^–1. Moreover, the practical application of rGO-Thy achieves almost 100% removal efficiency, and the treatment volumes of actual industrial wastewater using a fixed bed column are as high as 390 BV for Hg­(II), which indicates that rGO-Thy has great potential in advanced wastewater treatment

DataSheet1_Spatiotemporal variations and overflow risk analysis of the Salt Lake in the Hoh Xil Region using machine learning methods.PDF

Global warming is inducing dramatic changes in fluvial geomorphology and reshaping the hydrological connections between rivers and lakes. The water level and area of the Salt Lake have increased rapidly since the outburst of the Zonag Lake in the Hoh Xil region of the Qinghai–Tibet Plateau in 2011, threatening the downstream infrastructure. However, fewer studies have focused on its spatiotemporal variation and overflow risk over long time series. Here, we used three machine learning algorithms: Classification and Regression Trees (CART), Random Forest (RF), and Support Vector Machine (SVM) to extract the area of the Salt Lake for a long time series, analyzed its spatiotemporal variation from 1973 to 2021, and finally assessed the overflow risk. The Kappa coefficient (KAPPA) and the overall accuracy (OA) were used to evaluate the performance of the models. The results showed that Random Forest performs superior in lake extraction (KAPPA = 0.98, overall accuracy = 0.99), followed by Classification and Regression Trees and Support Vector Machine. normalized difference water index is the relatively important feature variable in both RF and CART. Before the outburst event, the area change of the Salt Lake was consistent with the variation in precipitation; after that, it showed a remarkable area increase (circa 350%) in all orientations, and the main direction was the southeast. Without the construction of the emergency drainage channel, the simulation result indicated that the earliest and latest times of the Salt Lake overflow event are predicted to occur in 2020 and 2031, respectively. The results of this paper not only demonstrate that RF is more suitable for water extraction and help understand the water system reorganization event.</p

Video_2_Case report: Anti-NMDA receptor encephalitis manifesting as rapid weight loss and abnormal movement disorders with alternating unilateral ptosis and contralateral limb tremor.mp4

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, associated with immunoglobulin G (IgG) autoantibodies against the GluN1 subunit of the NMDAR, is one of the most common types of autoimmune encephalitis. In patients with anti-NMDAR encephalitis, movement disorders (MDs) are often frequent, mainly presenting as facial dyskinesias and stereotyped movements. The alternating clinical manifestation of limb tremor with unilateral ptosis is rare. Here, we report an interesting case of a 22-year-old woman with rapid weight loss presenting with staged dyskinesia. Interestingly, she typically showed persistent tremor of the right upper limb, which would stop when her left upper eyelid drooped uncontrollably, a phenomenon that lasted for a few seconds, followed by automatic upper eyelid lift and continued persistent tremor of the upper limb. Moreover, it was fortunate to find anti-NMDAR antibodies in her cerebrospinal fluid (CSF), which indicated the patient had anti-NMDAR encephalitis. And abnormal apparent diffusion coefficient (ADC) hyperintense signals on the left midbrain interpeduncular fossa explained this manifestation of focal neurological deficit. After the systematic administration of immunotherapy (intravenous immunoglobulin, IVIG), steroid pulse therapy, and symptomatic treatment, the initial symptoms were significantly relieved except for limb tremor. The MDs were becoming less visible for the next six months under topiramate prescriptions. Noteworthy, there are no specific MD phenotypes in anti-NMDAR encephalitis. We describe the young women with unique MDs and rapid weight loss to help us get a more comprehensive understanding of anti-NMDAR encephalitis. </p

Study on the adsorption of nitrogen and phosphorus from biogas slurry by NaCl-modified zeolite

<div><p>A NaCl-modified zeolite was used to simultaneously remove nitrogen and phosphate from biogas slurry. The effect of pH, contact time and dosage of absorbants on the removal efficiency of nitrogen and phosphate were studied. The results showed that the highest removal efficiency of NH₄⁺-N (92.13%) and PO₄³⁻-P (90.3%) were achieved at pH 8. While the zeolite doses ranged from 0.5 to 5 g/100 ml, NH₄⁺-N and PO₄³⁻-P removal efficiencies ranged from 5.19% to 94.94% and 72.16% to 91.63% respectively. The adsorption isotherms of N and P removal with NaCl-modified zeolite were well described by Langmuir models, suggesting the homogeneous sorption mechanisms. While through intra-particle diffusion model to analyze the influence of contact time, it showed that the adsorption process of NH₄⁺-N and PO₄³⁻-P followed the second step of intra-particle diffusion model. The surface diffusion adsorption step was very fast which was finished in a short time.</p></div

Recovery of Lithium from Wastewater Using Development of Li Ion-Imprinted Polymers

Recycling lithium from waste lithium batteries is a growing problem, and new technologies are needed to recover the lithium. Currently, there is a lack of highly selective adsorption/ion exchange materials that can be used to recover lithium. We have developed a magnetic lithium ion-imprinted polymer (Fe₃O₄@SiO₂@IIP) by using novel crown ether. The Fe₃O₄@SiO₂@IIP has been synthesized by a surface imprinting technique using our newly synthesized 2-(allyloxy) methyl-12-crown-4 as a functional monomer. The Fe₃O₄@SiO₂@IIP was analyzed by Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The optimum pH for adsorption is 6. Fe₃O₄@SiO₂@IIP shows fast adsorption kinetics for lithium ions (10 min to reach complete equilibrium), and the adsorption process obeys an external mass transfer model. Homogeneous binding sites are proved by the Langmuir isotherm, and the maximum adsorption capacity is 0.586 mmol/g. Fe₃O₄@SiO₂@IIP has excellent selectivity for Li­(I) because the selectivity separation factors of Li­(I) with respect to Na­(I), K­(I), Cu­(II), and Zn­(II) are 50.88, 42.38, 22.5, and 22.2, respectively. The adsorption capacity of sorbent remained above 92% after five cycles. Fixed-bed column adsorption experiments indicate that the effective treatment volume was 140 bed volumes (BV) in the first run with a breakthrough of 10% of the inlet concentration for an inlet concentration of 0.5 mmol/L, and 110 BV was treated for the second run under identical conditions. We demonstrated that 89.8% of the lithium was recovered during bed regeneration using 0.5 mol/L HCl solution. Fe₃O₄@SiO₂@IIP also exhibited excellent removal efficiency for Li­(I) in real wastewater, validating its great potential in advanced wastewater treatment. Accordingly, we have developed a new method for wastewater treatment that meets Li emission standards, and recovery of Li creates economic interest

Video_1_Case report: Anti-NMDA receptor encephalitis manifesting as rapid weight loss and abnormal movement disorders with alternating unilateral ptosis and contralateral limb tremor.mp4

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, associated with immunoglobulin G (IgG) autoantibodies against the GluN1 subunit of the NMDAR, is one of the most common types of autoimmune encephalitis. In patients with anti-NMDAR encephalitis, movement disorders (MDs) are often frequent, mainly presenting as facial dyskinesias and stereotyped movements. The alternating clinical manifestation of limb tremor with unilateral ptosis is rare. Here, we report an interesting case of a 22-year-old woman with rapid weight loss presenting with staged dyskinesia. Interestingly, she typically showed persistent tremor of the right upper limb, which would stop when her left upper eyelid drooped uncontrollably, a phenomenon that lasted for a few seconds, followed by automatic upper eyelid lift and continued persistent tremor of the upper limb. Moreover, it was fortunate to find anti-NMDAR antibodies in her cerebrospinal fluid (CSF), which indicated the patient had anti-NMDAR encephalitis. And abnormal apparent diffusion coefficient (ADC) hyperintense signals on the left midbrain interpeduncular fossa explained this manifestation of focal neurological deficit. After the systematic administration of immunotherapy (intravenous immunoglobulin, IVIG), steroid pulse therapy, and symptomatic treatment, the initial symptoms were significantly relieved except for limb tremor. The MDs were becoming less visible for the next six months under topiramate prescriptions. Noteworthy, there are no specific MD phenotypes in anti-NMDAR encephalitis. We describe the young women with unique MDs and rapid weight loss to help us get a more comprehensive understanding of anti-NMDAR encephalitis. </p

Video_3_Case report: Anti-NMDA receptor encephalitis manifesting as rapid weight loss and abnormal movement disorders with alternating unilateral ptosis and contralateral limb tremor.mp4

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, associated with immunoglobulin G (IgG) autoantibodies against the GluN1 subunit of the NMDAR, is one of the most common types of autoimmune encephalitis. In patients with anti-NMDAR encephalitis, movement disorders (MDs) are often frequent, mainly presenting as facial dyskinesias and stereotyped movements. The alternating clinical manifestation of limb tremor with unilateral ptosis is rare. Here, we report an interesting case of a 22-year-old woman with rapid weight loss presenting with staged dyskinesia. Interestingly, she typically showed persistent tremor of the right upper limb, which would stop when her left upper eyelid drooped uncontrollably, a phenomenon that lasted for a few seconds, followed by automatic upper eyelid lift and continued persistent tremor of the upper limb. Moreover, it was fortunate to find anti-NMDAR antibodies in her cerebrospinal fluid (CSF), which indicated the patient had anti-NMDAR encephalitis. And abnormal apparent diffusion coefficient (ADC) hyperintense signals on the left midbrain interpeduncular fossa explained this manifestation of focal neurological deficit. After the systematic administration of immunotherapy (intravenous immunoglobulin, IVIG), steroid pulse therapy, and symptomatic treatment, the initial symptoms were significantly relieved except for limb tremor. The MDs were becoming less visible for the next six months under topiramate prescriptions. Noteworthy, there are no specific MD phenotypes in anti-NMDAR encephalitis. We describe the young women with unique MDs and rapid weight loss to help us get a more comprehensive understanding of anti-NMDAR encephalitis. </p

FI-IR spectra obtained for natural zeolite and NaCl-modified zeolite.

<p>FI-IR spectra obtained for natural zeolite and NaCl-modified zeolite.</p

Optimal conditions for nutrients removal.

<p>(A)Effect of pH. (B) Effect of reaction time on removal efficiency of NH₄⁺-N and PO₄³⁻-P by NaCl-modified zeolite (1 g/100 ml). (C) Effect of dosage on removal efficiency of NH₄⁺-N and PO₄³⁻-P by NaCl-modified zeolite (1 g/100 ml).</p