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To address the problems of slow detection speed and low accuracy commonly found in cigarette factory warehouse workshops when detecting tobacco moth, a visual detection method for tobacco moth in cigarette factories based on improved lightweight YOLOv5s was developed. The method utilizes the correlation and redundancy between feature maps to design the EESP-Ghost module, and uses this module as the basis for designing a double-attention Ghost-bneck block incorporating an efficient spatial pyramid, which is introduced into the YOLOv5s model to achieve lightweighting of the deep neural network model while improving the detection accuracy. The method is used for validation experiments on the tobacco moth dataset. The results showed that the method improved the average accuracy by 4.37% with only 49.88% of the original YOLOv5s parameter count. When the tobacco moth adhering to the sticky board was detected in a real detection scenario, the method has high detection confidence and correct detection number, which could realize the high-precision real-time detection of the tobacco moth in the cigarette factory, and provide a guarantee for the effective control of the tobacco moth. [ABSTRACT FROM AUTHOR]

An expanded-sandwich system is a nonlinear extended block-oriented system in which memoryless elements in conventional block-oriented systems are displaced by memory submodels. Expanded-sandwich system identification has received extensive attention in recent years due to the powerful ability of these systems to describe actual industrial systems. This study proposes a novel recursive identification algorithm for an expanded-sandwich system, in which an estimator is developed on the basis of parameter identification error data rather than the traditional prediction error output information. In this scheme, a filter is introduced to extract the available system information based on miserly structure layout, and some intermediate variables are designed using filtered vectors. According to the developed intermediate variables, the parameter identification error data can be obtained. Thereafter, an adaptive estimator is established by integrating the identification error data compared with the classic adaptive estimator based on the prediction error output information. Thus, the design framework introduced in this research provides a new perspective for the design of identification algorithms. Under a general continuous excitation condition, the parameter estimation values can converge to the true values. Finally, experimental results and illustrative examples indicate the availability and usefulness of the proposed method. [ABSTRACT FROM AUTHOR]

In order to solve the harmonic suppression failure and harmonic surge in workshop distribution system caused by the fault of Active Power Filter (APF) bridge arm, a model predictive fault-tolerant control strategy was proposed. By analyzing the working principle of APF fault-tolerant transformation topology, the relationship of voltage vector transformation after fault-tolerant was revealed, and the prediction model of harmonic compensation current was established. A fast harmonic detection method based on the second-order generalized integral orthogonal generator (SOGI) was designed, and the harmonic compensation current output by SOGI was used as the reference instruction of the predictive control. According to the current predictive model and the reference instruction, in the rhombus voltage vector set of the fault tolerant APF, the switching state satisfying the minimum cost function was selected to carry out model predictive control and harmonic compensation. Experiments results verifed that, in the condition of the bridge arm fault, the proposed control strategy could work continuously and suppress harmonic current. The total harmonic distortion(THD) of the power distribution line is reduced from 9. 91% to 4. 87%, which verified that the proposed method can improve the reliability and fault tolerant capability of APF equipment in the cigarette factory. [ABSTRACT FROM AUTHOR]

Aiming at the problem of insufficient stability of outlet moisture content in tobacco cut stem airflow drying, an integrated model combining trend prediction adjustment control and zoning feedback adjustment control was designed based on the original PID control model. The gap between the actual value and the set value of outlet moisture content was divided into several different intervals in this model, and a real-time control strategy was determined by the interval of gap lied in and the change trend in the interval. At the same time, according to the change trend of inlet moisture content, the change of outlet moisture content was predicted and necessary adjustments were taken. The practical application research results showed that the standard deviation of outlet moisture content in tobacco cut stem airflow drying was reduced by 27. 9% after applying the integrated control model, CPK increased by 45. 4%. The integrated control model could effectively improve the stability of outlet moisture content in tobacco cut stem airflow drying. [ABSTRACT FROM AUTHOR]

In the three-phase four-wire power distribution system of modern cigarette workshops, the zero-sequence current causes the midpoint voltage fluctuation on the DC side, which affects the harmonic control effect of active power filter (APF). To solve this problem, a model predictive reconstructed space voltage vector control strategy based on neutral point clamped (NPC) three-level APF was proposed. The APF harmonic control hierarchy analysis framework was constructed, the three performance indicators of midpoint voltage balance, zero sequence current compensation and space voltage vector utilization were designed, and the performance of various voltage vector indicators was evaluated. The 6 types of reconstructed space voltage vector combinations were quantitatively compared, and the combination with the highest evaluation score in the analytic hierarchy process was selected for model predictive harmonic control. Simulation and experimental results showed that compared with conventional control strategies, the proposed strategy could effectively control harmonics and balance the midpoint voltage of the DC side of the APF. [ABSTRACT FROM AUTHOR]

Objective: To prepare the silk fibroin microcarrier loaded with clematis total saponins (CTS) (CTS-silk fibroin microcarrier), and to investigate the effect of microcarrier combined with chondrocytes on promoting rabbit knee articular cartilage defects repair., Methods: CTS-silk fibroin microcarrier was prepared by high voltage electrostatic combined with freeze drying method using the mixture of 5% silk fibroin solution, 10 mg/mL CTS solution, and glycerin. The samples were characterized by scanning electron microscope and the cumulative release amount of CTS was detected. Meanwhile, unloaded silk fibroin microcarrier was also prepared. Chondrocytes were isolated from knee cartilage of 4-week-old New Zealand rabbits and cultured. The 3rd generation of chondrocytes were co-cultured with the two microcarriers respectively for 7 days in microgravity environment. During this period, the adhesion of chondrocytes to microcarriers was observed by inverted phase contrast microscope and scanning electron microscope, and the proliferation activity of cells was detected by cell counting kit 8 (CCK-8), and compared with normal cells. Thirty 3-month-old New Zealand rabbits were selected to make bilateral knee cartilage defects models and randomly divided into 3 groups ( n =20). Knee cartilage defects in group A were not treated, and in groups B and C were filled with the unloaded silk fibroin microcarrier-chondrocyte complexes and CTS-silk fibroin microcarrier-chondrocyte complexes, respectively. At 12 weeks after operation, the levels of matrix metalloproteinase 9 (MMP-9), MMP-13, and tissue inhibitor of MMP 1 (TIMP-1) in articular fluid were detected by ELISA. The cartilage defects were collected for gross observation and histological observation (HE staining and toluidine blue staining). Western blot was used to detect the expressions of collagen type Ⅱ and proteoglycan. The inflammatory of joint synovium was observed by histological staining and inducible nitric oxide synthase (iNOS) immunohistochemical staining., Results: The CTS-silk fibroin microcarrier was spherical, with a diameter between 300 and 500 μm, a porous surface, and a porosity of 35.63%±3.51%. CTS could be released slowly in microcarrier for a long time. Under microgravity, the chondrocytes attached to the surface of the two microcarriers increased gradually with the extension of culture time, and the proliferation activity of chondrocytes at 24 hours after co-culture was significantly higher than that of normal chondrocytes ( P <0.05). There was no significant difference in proliferation activity of chondrocytes between the two microcarriers ( P >0.05). In vivo experiment in animals showed that the levels of MMP-9 and MMP-13 in group C were significantly lower than those in groups A and B ( P <0.05), and the level of TIMP-1 in group C was significantly higher ( P <0.05). Compared with group A, the cartilage defects in groups B and C were filled with repaired tissue, and the repaired surface of group C was more complete and better combined with the surrounding cartilage. Histological observation and Western blot analysis showed that the International Cartilage Repair Scoring (ICRS) and the relative expression levels of collagen type Ⅱ and proteoglycan in groups B and C were significantly better than those in group A, and group C was significantly better than group B ( P <0.05). The histological observation showed that the infiltration of synovial inflammatory cells and hyperplasia of small vessels significantly reduced in group C compared with groups A and B. iNOS immunohistochemical staining showed that the expression of iNOS in group C was significantly lower than that in groups A and B ( P <0.05)., Conclusion: CTS-silk fibroin microcarrier has good CTS sustained release effect and biocompatibility, and can promote the repair of rabbit cartilage defect by carrying chondrocyte proliferation in microgravity environment.

As a kind of mechanical effector cells, chondrocytes can produce a variety of physical and chemical signals under the stimulation of multiaxial load in vivo , which affect their own growth, development and apoptosis. Therefore, simulating the mechanical environment in vivo has become a research hotspot in the culture of chondrocytes in vitro . Although a large number of reports have fully proved that different mechanical stimulation can regulate the metabolism of chondrocytes, the loading scheme has not been agreed. Starting from different mechanical forms, this review will explore the differences in the regulation of chondrocyte metabolism by different mechanical stimuli, so as to find an advantage scheme to promote the growth and proliferation of chondrocytes and to develop a more stable, effective and reliable experimental strategy.