Data filtering-based least squares iterative algorithm for Hammerstein nonlinear systems by using the model decomposition

This paper focuses on the iterative identification problems for a class of Hammerstein nonlinear systems. By decomposing the system into two fictitious subsystems, a decomposition-based least squares iterative algorithm is presented for estimating the parameter vector in each subsystem. Moreover, a data filtering-based decomposition least squares iterative algorithm is proposed. The simulation results indicate that the data filtering-based least squares iterative algorithm can generate more accurate parameter estimates than the least squares iterative algorithm

Combined state and parameter estimation for Hammerstein systems with time-delay using the Kalman filtering

This paper discusses the state and parameter estimation problem for a class of Hammerstein state space systems with time-delay. Both the process noise and the measurement noise are considered in the system. Based on the observable canonical state space form and the key term separation, a pseudo-linear regressive identification model is obtained. For the unknown states in the information vector, the Kalman filter is used to search for the optimal state estimates. A Kalman-filter based least squares iterative and a recursive least squares algorithms are proposed. Extending the information vector to include the latest information terms which are missed for the time-delay, the Kalman-filter based recursive extended least squares algorithm is derived to obtain the estimates of the unknown time-delay, parameters and states. The numerical simulation results are given to illustrate the effectiveness of the proposed algorithms

Effect of a combination of donepezil tablets and butylphthalide soft capsules on neurological function in dementia patients, and its effect on serum inflammatory factors

Purpose: To determine the effect of combined use of donepezil tablets and butylphthalide soft capsules in the treatment of patients with vascular dementia, and its effect on serum inflammatory factor levels and neurological functional recovery of patients.Methods: 120 patients with vascular dementia were selected and assigned to group A (n = 60) and group B (n = 60). All patients were treated with donepezil tablets, while patients in group A were, in addition, treated with butylphthalide soft capsules. Mini mental state examination (MMSE) scores, clinical dementia rating scale (CDRS) scores, activities of daily living (ADL) scores, incidence of adverse reactions, serum inflammatory factor levels and neurological functional recovery were determined.Results: There was significantly higher MMSE score in group A than in B, while CDRS score was lower in group A. The ADL scores and inflammatory factor levels were lower in group A than in B (p < 0.001), while neurological functional recovery was markedly better in A (p < 0.001). Incidents of unwanted events were comparable in groups A and B, and there were no serious complications in the patients.Conclusion: The combination therapy of donepezil tablets and butylphthalide soft capsules reduces inflammatory factor levels and improved cognitive level and quality of life of patients with vascular dementia. It also produces good neurological functional recovery and low incidence of adverse reactions. Therefore, this treatment strategy has potentials for the management of vascular dementia

Asymmetric Flow Control in a Slab Mold through a New Type of Electromagnetic Field Arrangement

This research aims to investigate the control effect of asymmetric flow in a slab mold using a novel magnetic field arrangement: freestanding adjustable combination electromagnetic brake (FAC-EMBr). Three scenarios (submerged entry nozzle moves to the narrow face, wide face of the slab mold, and rotates 10°) were studied using three-dimensional numerical simulation. The results show that the magnetic field generated by the FAC-EMBr system can effectively cover three key zones in mold and that the magnetic flux density in the zone cover by a vertical magnetic pole can be adjusted according to the actual flow condition. The FAC-EMBr can effectively improve the asymmetric flow in a mold and near the narrow surface caused by the asymmetric arrangement of the nozzle and can effectively inhibit the occurrence of the flow deviation phenomenon and stabilize the steel/slag interface fluctuation. At the same time, FAC-EMBr has obvious inhibition effects on the surface velocity and can optimize the asymmetric distribution of the surface velocity and the upper reflux velocity caused by the asymmetric arrangement of the nozzle. This study can provide theoretical evidence for the development and utilization of a new electromagnetic brake technology

Description and Application of a Mathematical Method for the Analysis of Harmony

Harmony issues are widespread in human society and nature. To analyze these issues, harmony theory has been proposed as the main theoretical approach for the study of interpersonal relationships and relationships between humans and nature. Therefore, it is of great importance to study harmony theory. After briefly introducing the basic concepts of harmony theory, this paper expounds the five elements that are essential for the quantitative description of harmony issues in water resources management: harmony participant, harmony objective, harmony regulation, harmony factor, and harmony action. A basic mathematical equation for the harmony degree, that is, a quantitative expression of harmony issues, is introduced in the paper: HD=ai − bj, where a is the uniform degree, b is the difference degree, i is the harmony coefficient, and j is the disharmony coefficient. This paper also discusses harmony assessment and harmony regulation and introduces some application examples

Multidirection gradient iterative algorithm: A unified framework for gradient iterative and least squares algorithms

In this article, a multidirection-based gradient iterative (GI) algorithm for Hammerstein systems with irregular sampling data is proposed. The algorithm updates the parameter estimates using several orthogonal directions at each iteration. The convergence rate is significantly improved with an increasing number of directions. The convergence property and two simulation examples are provided to demonstrate the effectiveness of the proposed algorithm. In addition, the multidirection-based GI algorithm establishes a relationship between the traditional GI and least squares (LS) algorithms. Thus, our algorithm that combines the LS and GI algorithms constructs an identification framework for a significantly wider class of systems

Mechanisms Of Cannabinoid Cb 2 Receptor-Mediated Reduction Of Dopamine Neuronal Excitability In Mouse Ventral Tegmental Area

Background: We have recently reported that activation of cannabinoid type 2 receptors (CB 2 Rs)reduces dopamine (DA)neuron excitability in mouse ventral tegmental area (VTA). Here, we elucidate the underlying mechanisms. Methods: Patch-clamp recordings were performed in mouse VTA slices and dissociated single VTA DA neurons. Findings: Using cell-attached recording in VTA slices, bath-application of CB 2 R agonists (JWH133 or five other CB 2 R agonists)significantly reduced VTA DA neuron action potential (AP)firing rate. Under the patch-clamp whole-cell recording model, JWH133 (10 μM)mildly reduced the frequency of miniature excitatory postsynaptic currents (mEPSCs)but not miniature inhibitory postsynaptic currents (mIPSCs). JWH133 also did not alter evoked EPSCs or IPSCs. In freshly dissociated VTA DA neurons, JWH133 reduced AP firing rate, delayed AP initiation and enhanced AP after-hyperpolarization. In voltage-clamp recordings, JWH133 (1 μM)enhanced M-type K + currents and this effect was absent in CB 2−/− mice and abolished by co-administration of a selective CB 2 R antagonist (10 μM, AM630). CB 2 R-mediated inhibition in VTA DA neuron firing can be mimicked by M-current opener (10 μM retigabine)and blocked by M-current blocker (30 μM XE991). In addition, enhancement of neuronal cAMP by forskolin (10 μM)reduced M-current and increased DA neuron firing rate. Finally, pharmacological block of synaptic transmission by NBQX (10 μM), D-APV (50 μM)and picrotoxin (100 μM)in VTA slices failed to prevent CB 2 R-mediated inhibition, while intracellular infusion of guanosine 5\u27-O-2-thiodiphosphate (600 μM, GDP-β-S)through recording electrode to block postsynaptic G-protein function prevented JWH133-induced reduction in AP firing. Interpretation: Our results suggest that CB 2 Rs modulate VTA DA neuron excitability mainly through an intrinsic mechanism, including a CB 2 R-mediated reduction of intracellular cAMP, and in turn enhancement of M-type K + currents. Fund: This research was supported by the Barrow Neuroscience Foundation, the BNI-BMS Seed Fund, and CNSF (81771437)

Conical beam monopole antenna design for Chinese area positioning system

This article describes the operational principle of the satellite-based Chinese Area Positioning System (CAPS) and proposes a monopole antenna for a large anchored buoy platform in harsh marine environment. The proposed antenna is highly omnidirectional with sufficiently wide half-power beamwidth (HPBW) greater than 40˚ (i.e., not less than ±20° swing) by using a conical ground plane, taking into account the geostationary satellite position, link budget, sea conditions, volume and cost. The impedance bandwidth defined by 10 dB return loss is 750 MHz (5.60-6.35 GHz), and the main lobe direction and the half-power beamwidth are about 46° and 43° at the operating frequency 5.885 GHz, respectively. The antenna prototype has been installed on-site to test its performance in sea. The results confirm that the proposed antenna is a suitable candidate for a variety of CAPS applications in China

OsbZIP18, a Positive Regulator of Serotonin Biosynthesis, Negatively Controls the UV-B Tolerance in Rice

Serotonin (5-hydroxytryptamine) plays an important role in many developmental processes and biotic/abiotic stress responses in plants. Although serotonin biosynthetic pathways in plants have been uncovered, knowledge of the mechanisms of serotonin accumulation is still limited, and no regulators have been identified to date. Here, we identified the basic leucine zipper transcription factor OsbZIP18 as a positive regulator of serotonin biosynthesis in rice. Overexpression of OsbZIP18 strongly induced the levels of serotonin and its early precursors (tryptophan and tryptamine), resulting in stunted growth and dark-brown phenotypes. A function analysis showed that OsbZIP18 activated serotonin biosynthesis genes (including tryptophan decarboxylase 1 (OsTDC1), tryptophan decarboxylase 3 (OsTDC3), and tryptamine 5-hydroxylase (OsT5H)) by directly binding to the ACE-containing or G-box cis-elements in their promoters. Furthermore, we demonstrated that OsbZIP18 is induced by UV-B stress, and experiments using UV-B radiation showed that transgenic plants overexpressing OsbZIP18 exhibited UV-B stress-sensitive phenotypes. Besides, exogenous serotonin significantly exacerbates UV-B stress of OsbZIP18_OE plants, suggesting that the excessive accumulation of serotonin may be responsible for the sensitivity of OsbZIP18_OE plants to UV-B stress. Overall, we identified a positive regulator of serotonin biosynthesis and demonstrated that UV-B-stress induced serotonin accumulation, partly in an OsbZIP18-dependent manner

Aflatoxin B1 Degradation by Stenotrophomonas Maltophilia and Other Microbes Selected Using Coumarin Medium#

Aflatoxin B1 (AFB1) is one of the most harmful mycotoxins in animal production and food industry. A safe, effective and environmentally sound detoxification method is needed for controlling this toxin. In this study, 65 samples were screened from various sources with vast microbial populations using a newly developed medium containing coumarin as the sole carbon source. Twenty five single-colony bacterial isolates showing AFB1 reduction activity in a liquid culture medium were selected from the screen. Isolate 35-3, obtained from tapir feces and identified to be Stenotrophomonas maltophilia, reduced AFB1 by 82.5% after incubation in the liquid medium at 37 °C for 72 h. The culture supernatant of isolate 35-3 was able to degrade AFB1 effectively, whereas the viable cells and cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Activity was reduced to 60.8% and 63.5% at 20 °C and 30 °C, respectively, from 78.7% at 37 °C. The highest degradation rate was 84.8% at pH 8 and the lowest was only 14.3% at pH 4.0. Ions Mg2+ and Cu2+ were activators for AFB1 degradation, however ion Zn2+ was a strong inhibitor. Treatments with proteinase K, proteinase K plus SDS and heating significantly reduced or eradicated the degradation activity of the culture supernatant. The results indicated that the degradation of AFB1 by S. maltophilia 35-3 was enzymatic and could have a great potential in industrial applications