Smoke and fire detection technology is a key technology for automatically realizing forest monitoring and forest fire warning. One of the most popular algorithms for object detection tasks is YOLOv5. ...However, it suffers from some challenges, such as high computational load and limited detection performance. This paper proposes a high-performance lightweight network model for detecting forest smoke and fire based on YOLOv5 to overcome these problems. C3Ghost and Ghost modules are introduced into the Backbone and Neck network to achieve the purpose of reducing network parameters and improving the feature's expressing performance. Coordinate Attention (CA) module is introduced into the Backbone network to highlight the object's important information about smoke and fire and to suppress irrelevant background information. In Neck network part, in order to distinguish the importance of different features in feature fusing process, the weight parameter of feature fusion is added which is based on PAN (path aggregation network) structure, which is named PAN-weight. Multiple sets of controlled experiments were conducted to confirm the proposed method's performance. Compared with YOLOv5s, the proposed method reduced the model size and FLOPs by 44.75% and 47.46% respectively, while increased precision and mAP(mean average precision)@0.5 by 2.53% and 1.16% respectively. The experimental results demonstrated the usefulness and superiority of the proposed method. The core code and dataset required for the experiment are saved in this article at
Typical ionization waves (IWs) are observed during the propagation of nanosecond pulsed atmospheric pressure plasma jets (APPJs) with argon flow, combining both the measurement of the axial electric ...field (Ez) and the temporal resolved optical imaging. The movement of the luminous APPJ head is recognized as the development of the IW front, accompanied with the propagation of the peak electric field. Especially, the radial distribution of Ez transits from a central peak profile before the IW front arrives to a hollow profile after the pass of the IW front. As for the temporal Ez trend, there is a mode transition from the single‐peak feature under a low peak voltage to the double‐peak feature under a higher peak voltage, indicating the existence of both primary and secondary IWs. The effect of target conditions on the IWs in APPJs is also explored. With a metal target, no residual electric field is observed before imposing the high‐voltage pulses. However, with a dielectric target, the residual surface charges generate a background electric field in the opposite direction to that during IW propagation. In the free APPJ (with no target), on the voltage falling edge, a negative electric field drives the electron flow to compensate the positive ions left over during the forward IW propagation on the voltage rising edge.
High-intensity land use and resource overloaded-induced regional land use spatial pattern (LUSP) are essential and challenging for high-quality development. The empirical studies have shown that a ...scientific land uses spatial layout, and the supporting system should be based on a historical perspective and require better considering the double influence between the current characteristics and future dynamics. This study proposes a comprehensive framework that integrates the resource environment carrying capacity (RECC) and land use change (LUC) to investigate strategies for optimizing the spatial pattern of land use for high-quality development. China’s Zhengzhou city was the subject of a case study whose datasets include remote sensing, spatial monitoring, statistics, and open sources. Three significant results emerged from the analysis: (1) The RECC has significant spatial differentiation but does not follow a specific spatial law, and regions with relatively perfect ecosystems may not necessarily have better RECC. (2) From 2020 to 2030, the construction land and farmland will fluctuate wildly, with the former increasing by 346.21 km
2
and the latter decreasing by 295.98 km
2
. (3) The study area is divided into five zones, including resource conservation, ecological carrying, living core, suitable construction, and grain supply zones, and each one has its LUSP optimization orientation. This uneven distribution of RECC reflects functional defects in the development and utilization of LUSP. In addition, the increase in construction land and the sharp decline of farmland pose potential threats to the sustainable development of the study area. Hence, these two elements cannot be ignored in the future high-quality development process. The findings indicate that the LUSP optimization based on dual dimensions of RECC and LUC is more realistic than a single-dimension solution, exhibiting the LUSP optimization’s effectiveness and applicability.
Electrolytic capacitor-less drive systems have a higher lifespan and reliability. However, the DC-link voltage of ECL drive systems has a sudden change under dynamic conditions, which results in a ...serious degradation of the drive system performance. To solve the problem, this paper proposes a model predictive current control (MPCC) based on motor power change. A grid current predictive model based on motor power change is established. Motor power change is introduced into the cost function, so that grid power can quickly and accurately track the motor power under dynamic conditions, thereby effectively avoiding the sudden change of the DC-link voltage. Meanwhile, the current predictive model for decoupling inductor in the asymmetric split-capacitor active power decoupling circuit (APDC) is constructed. It realizes the high-precision complementary control of the split-capacitor voltages under various working conditions, and effectively reduces the DC-link voltage ripple. The experimental results verify the effectiveness of the proposed MPCC.
Cemented carbide used in the rotor of a mud pulser is subjected to the scouring action of solid particles and corrosive mud media for a long time, which causes abrasive wear and electrochemical ...corrosion. To improve the wear and corrosive resistance of cemented carbide, samples with different cobalt content (WC-5Co, WC-8Co, and WC-10Co) receive deep cryogenic treatment (DCT) at -196 °C for 2.5 h. An optical metalloscope (OM) and X-ray diffractometer (XRD) are used to observe the phase changes of cemented carbides, and the XRD is also used to observe the change in residual stress on the cemented carbide's surface. A scanning electron microscope (SEM) is used to characterize the wear and electrochemical corrosion surface microstructure of cemented carbides (untreated and DCT). The results show that the DCT promotes the precipitation of the η phase, and the diffraction peak of ε-Co tends to intensify. Compared with the untreated, the wear rates of WC-5Co, WC-8Co, and WC-10Co can be reduced by 14.71%, 37.25%, and 41.01% by DCT, respectively. The wear form of the cemented carbides is mainly the extrusion deformation of Co and WC shedding. The precipitation of the η phase and the increase in WC residual compressive stress by DCT are the main reasons for the improvement of wear resistance. The electrochemical corrosion characteristic is the dissolution of the Co phase. DCT causes the corrosion potential of cemented carbide to shift forward and the corrosion current density to decrease. The enhancement of the corrosion resistance of cemented carbide caused by DCT is due to the Co phase transition, η phase precipitation, and the increase in the compressive stress of cemented carbide.
A bi‐level planning strategy of a hydrogen‐supercapacitor hybrid energy storage system (H‐S HESS) has been proposed in this study for wind power fluctuation suppression. The proposed system consists ...of a supercapacitor array and a hydrogen energy storage unit, and the bi‐level planning strategy consists of an Energy Management Level and a Capacity Configuration Level. In the upper level, with Hilbert–Huang transform frequency analysis, a novel energy management strategy based on adaptive power allocation (APA) is designed. The lower level applies multi‐objective Harris hawks optimizer to solve the optimal parameters of each device in the system. Based on the data measured from a 2‐MW wind system in a hydrogen‐electric coupled DC microgrid demonstration project, the optimal system capacity configuration scheme is obtained. The annualized cost of the system is $150,212, which is 41.1% lower than the scheme without optimization. The fluctuation unsuppressed rate of H‐S HESS is 0.64% under the APA strategy, which is only 0.14% higher than the conventional HESS (supercapacitor + lithium‐ion batteries) with the same annualized cost of system. The proposed strategy reduces the frequency of HESS operational power fluctuations, improves capacity configuration accuracy, and significantly decreases the cost gap between the proposed H‐S HESS and conventional structures.
To achieve the suppression of wind power fluctuations, this paper proposes a novel Hydrogen‐Supercapacitor (H‐S) hybrid energy storage system (HESS) with a bi‐level planning strategy based on adaptive power allocation and multi‐objective Harris hawks optimizer. Simulation is carried out using wind power data from a 2‐MW wind power system; the feasibility and effectiveness of this bi‐level planning strategy for the H‐S HESS structure were validated.
Ciprofol is a novel 2,6-disubstituted phenol derivative that has improved pharmacokinetic and pharmacodynamic properties compared with propofol. This study was conducted to compare the efficacy and ...safety of ciprofol-remifentanil
propofol-remifentanil for patients undergoing fiberoptic bronchoscopy.
Overall, 92 patients undergoing fiberoptic bronchoscopy were included in this prospective, randomized, double-blind, non-inferiority trial and were equally divided into two groups (n = 46 each). Fentanyl (50 μg) was given 2 min before the intravenous infusion of 0.3 mg/kg of ciprofol or 1.2 mg/kg of propofol over a time period of 30 s. During anesthesia maintenance, 0.05-0.2 μg/kg/min of remifentanil combined with one-third to one-fourth of the initial dose of ciprofol or propofol was repeated at 2-min intervals, as required, to maintain a Modified Observer's Assessment of Alertness and Sedation (MOAA/S) scale score <3. The primary outcome was the successful rate of fiberoptic bronchoscopy. Secondary outcomes included demographic characteristics, time metrics, hemodynamics, coughing severity, intubating conditions, lowest oxygen saturation, utilization of study drug doses, number of remedies (lidocaine and vasoactive drugs) used, satisfaction scores of both patients and the endoscopist, occurrence of intraoperative awareness, patients' willing to repeat fiberoptic bronchoscopy, and occurrence and severity of adverse events.
The successful completion rate of fiberoptic bronchoscopy was 91.30% (42 of 46; 95% confidence interval CI: 82.80%-99.80%) in the ciprofol-remifentanil group and 89.13% (41 of 46; 95% CI: 79.80%-98.50%) in the propofol-remifentanil group. Though the clinically acceptable intubating condition was improved in the ciprofol-remifentanil group, this difference has no clinical statistical difference (
> 0.05). No significant differences were noted between the two groups with respect to time metrics, consumption of fentanyl and remifentanil, or number of remedies (lidocaine and vasoactive drugs). Patients' willingness to repeat fiberoptic bronchoscopy and the satisfaction of both patients and endoscopist were significantly higher in the ciprofol-remifentanil than in the propofol-remifentanil group (
< 0.05). Compared with patients in the propofol-remifentanil group, patients in the ciprofol-remifentanil group had more stable hemodynamics. The lowest oxygen saturation was significantly higher in the ciprofol-remifentanil than in the propofol-remifentanil group (
< 0.05). The numbers of patients who experienced pain on injection in the ciprofol-remifentanil group was significantly lower than the number in the propofol-remifentanil group (
< 0.01). Severity of coughing, clinically acceptable severity of coughing, incidence of intraoperative awareness, and other adverse events were all similar between the two groups (
> 0.05). Only four patients experienced grade 2 adverse events (severe hypotension in one patient in the ciprofol-remifentanil group and three patients in the propofol-remifentanil group;
> 0.05); they were treated with noradrenaline.
Ciprofol-remifentanil was non-inferior to propofol-remifentanil with regard to successful sedation for flexible bronchoscopy, when used with pre-intravenous administration of 50 μg of fentanyl. At the same time, patients' willingness to repeat flexible bronchoscopy and the satisfactions were all significantly improved.
Traffic sign recognition and detection is a key technology in automatic vehicle driving and driver assistance systems. However, existing traffic sign recognition algorithms suffer from problems such ...as large model size, complex computation, high computational cost, which make it difficult to achieve an effective balance between detection speed and detection accuracy. This paper proposed an improved lightweight recognition algorithm, which is based on YOLOv5. This algorithm replaces the convolutional structure in the original YOLOv5 neck network with Ghost Module and C3Ghost Module, thereby reducing redundant features in the feature fusion process, lowering computational cost and the number of parameters. The structure of the PAN network was improved and the hybrid attention mechanism module CBAM was introduced to capture key information in traffic signs. Cross-layer connections were added to shorten the path of information transfer in feature pyramid network, which fused more features and improved the network feature recognition accuracy. In addition, the EIoU_Loss function was adopted as the bounding box regression loss function to improve the localization accuracy of the algorithm. The performance of the improved algorithm was also verified on the Chinese traffic sign dataset. Experimental results showed that the improved algorithm's detection accuracy was enhanced by 1.2%, while mAP@0.5 and mAP@0.5:0.95 were enhanced by 1.5% and 3.4% respectively over the existing YOLOv5 algorithm, and the overall parameter numbers and computational cost of the model were reduced by 14.5% and 16%. The proposed algorithm performs better than the current mainstream detection algorithms, has higher recognition accuracy in multiple environments, and meets the demand for real-time traffic sign recognition.
COVID-19 pneumonia is a disease that causes an existential health crisis in many people by directly affecting and damaging lung cells. The segmentation of infected areas from computed tomography (CT) ...images can be used to assist and provide useful information for COVID-19 diagnosis. Although several deep learning-based segmentation methods have been proposed for COVID-19 segmentation and have achieved state-of-the-art results, the segmentation accuracy is still not high enough (approximately 85%) due to the variations of COVID-19 infected areas (such as shape and size variations) and the similarities between COVID-19 and non-COVID-infected areas. To improve the segmentation accuracy of COVID-19 infected areas, we propose an interactive attention refinement network (Attention RefNet). The interactive attention refinement network can be connected with any segmentation network and trained with the segmentation network in an end-to-end fashion. We propose a skip connection attention module to improve the important features in both segmentation and refinement networks and a seed point module to enhance the important seeds (positions) for interactive refinement. The effectiveness of the proposed method was demonstrated on public datasets (COVID-19CTSeg and MICCAI) and our private multicenter dataset. The segmentation accuracy was improved to more than 90%. We also confirmed the generalizability of the proposed network on our multicenter dataset. The proposed method can still achieve high segmentation accuracy.
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