The water medium hydraulic retarder is the latest type of auxiliary braking device and has the characteristics of high power density,large braking torque,and compact structure.During traveling,this device can convert ...The water medium hydraulic retarder is the latest type of auxiliary braking device and has the characteristics of high power density,large braking torque,and compact structure.During traveling,this device can convert the kinetic energy of a vehicle to the heat energy of the cooling liquid and replace the service brake under non-emergency braking conditions.With regard to the constant-speed function of the water medium hydraulic retarder,this study designs a controller based on the neural network proportional-integral-derivative(PID)algorithm to achieve the steady traveling of the vehicle at constant velocity during a downhill course by controlling the filling ratio of the water medium hydraulic retarder.To validate the algorithm’s effectiveness,the dynamic model of the heavy-duty vehicle in the downhill process and the physical model of the water medium hydraulic retarder are developed.Three operating conditions,including a fixed slope,step-changing slope,and continuous changing slope,are set,and a simulation test is carried out in the MATLAB/Simulink environment.The neural network PID algorithm has better adaptability in controlling than the traditional PID algorithm.Thus,it controls the water medium hydraulic retarder such that the braking requirements of heavy-duty vehicles under a changing slope working condi-tion are satisfied,and it performs constant-speed control when the vehicle travels downhill.Therefore,the proposed control method can significantly improve the safety of road traffic.展开更多
Advances in software and hardware technologies have facilitated the production of quadrotor unmanned aerial vehicles(UAVs).Nowadays,people actively use quadrotor UAVs in essential missions such as search and rescue,co...Advances in software and hardware technologies have facilitated the production of quadrotor unmanned aerial vehicles(UAVs).Nowadays,people actively use quadrotor UAVs in essential missions such as search and rescue,counter-terrorism,firefighting,surveillance,and cargo transportation.While performing these tasks,quadrotors must operate in noisy environments.Therefore,a robust controller design that can control the altitude and attitude of the quadrotor in noisy environments is of great importance.Many researchers have focused only on white Gaussian noise in their studies,whereas researchers need to consider the effects of all colored noises during the operation of the quadrotor.This study aims to design a robust controller that is resistant to all colored noises.Firstly,a nonlinear quadrotormodel was created with MATLAB.Then,a backstepping controller resistant to colored noises was designed.Thedesigned backstepping controller was tested under Gaussian white,pink,brown,blue,and purple noises.PID and Lyapunov-based controller designswere also carried out,and their time responses(rise time,overshoot,settling time)were compared with those of the backstepping controller.In the simulations,time was in seconds,altitude was in meters,and roll,pitch,and yaw references were in radians.Rise and settling time values were in seconds,and overshoot value was in percent.When the obtained values are examined,simulations prove that the proposed backstepping controller has the least overshoot and the shortest settling time under all noise types.展开更多
The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,...The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.展开更多
Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and...Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.展开更多
Renewable Energy Systems(RES)provide a sustainable solution to climate warming and environmental pollution by enhancing stability and reliability through status acquisition and analysis on cloud platforms and intellig...Renewable Energy Systems(RES)provide a sustainable solution to climate warming and environmental pollution by enhancing stability and reliability through status acquisition and analysis on cloud platforms and intelligent processing on edge servers(ES).However,securely distributing encrypted data stored in the cloud to terminals that meet decryption requirements has become a prominent research topic.Additionally,managing attributes,including addition,deletion,and modification,is a crucial issue in the access control scheme for RES.To address these security concerns,a trust-based ciphertext-policy attribute-based encryption(CP-ABE)device access control scheme is proposed for RES(TB-CP-ABE).This scheme effectivelymanages the distribution and control of encrypted data on the cloud through robust attribute key management.By introducing trust management mechanisms and outsourced decryption technology,the ES system can effectively assess and manage the trust worthiness of terminal devices,ensuring that only trusted devices can participate in data exchange and access sensitive information.Besides,the ES system dynamically evaluates trust scores to set decryption trust thresholds,thereby regulating device data access permissions and enhancing the system’s security.To validate the security of the proposed TB-CP-ABE against chosen plaintext attacks,a comprehensive formal security analysis is conducted using the widely accepted random oraclemodel under the decisional q-Bilinear Diffie-Hellman Exponent(q-BDHE)assumption.Finally,comparative analysis with other schemes demonstrates that the TB-CP-ABE scheme cuts energy/communication costs by 43%,and scaleswell with rising terminals,maintaining average latency below 50ms,ensuring real-time service feasibility.The proposed scheme not only provides newinsights for the secure management of RES but also lays a foundation for future secure energy solutions.展开更多
The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow ...The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.展开更多
It’s possible for malicious operators to seize hold of electrical control systems, for instance, the engine control unit of driverless vehicles, from various vectors, e.g. autonomic control system, remote vehicle acc...It’s possible for malicious operators to seize hold of electrical control systems, for instance, the engine control unit of driverless vehicles, from various vectors, e.g. autonomic control system, remote vehicle access, or human drivers. To mitigate potential risks, this paper provides the inauguration study by proposing a theoretical framework in the physical, human and cyber triad. Its goal is to, at each time point, detect adversary control behaviors and protect control systems against malicious operations via integrating a variety of methods. This paper only proposes a theoretical framework which tries to indicate possible threats. With the support of the framework, the security system can lightly reduce the risk. The development and implementation of the system are out of scope.展开更多
In this paper, we proposed an output voltage stabilization of a DC-DC Zeta converter using hybrid control. We modeled the Zeta converter under continuous conduction mode operation. We derived a switching control law t...In this paper, we proposed an output voltage stabilization of a DC-DC Zeta converter using hybrid control. We modeled the Zeta converter under continuous conduction mode operation. We derived a switching control law that brings the output voltage to the desired level. Due to infinite switching occurring at the desired level, we enhanced the switching control law by allowing a sizeable output voltage ripple. We derived mathematical models that allow one to choose the desired switching frequency. In practice, the existence of the non-ideal properties of the Zeta converter results in steady-state output voltage error. By analyzing the power loss in the zeta converter, we proposed an improved switching control law that eliminates the steady-state output voltage error. The effectiveness of the proposed method is illustrated with simulation results.展开更多
Uneven power distribution,transient voltage,and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island modes.In response to these issues,th...Uneven power distribution,transient voltage,and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island modes.In response to these issues,this paper proposes a grid-connected/island switching control strategy for photovoltaic storage hybrid inverters based on the modified chimpanzee optimization algorithm.The proposed strategy incorporates coupling compensation and power differentiation elements based on the traditional droop control.Then,it combines the angular frequency and voltage amplitude adjustments provided by the phase-locked loop-free pre-synchronization control strategy.Precise pre-synchronization is achieved by regulating the virtual current to zero and aligning the photovoltaic storage hybrid inverter with the grid voltage.Additionally,two novel operators,learning and emotional behaviors are introduced to enhance the optimization precision of the chimpanzee algorithm.These operators ensure high-precision and high-reliability optimization of the droop control parameters for photovoltaic storage hybrid inverters.A Simulink model was constructed for simulation analysis,which validated the optimized control strategy’s ability to evenly distribute power under load transients.This strategy effectively mitigated transient voltage and current surges during mode transitions.Consequently,seamless and efficient switching between gridconnected and island modes was achieved for the photovoltaic storage hybrid inverter.The enhanced energy utilization efficiency,in turn,offers robust technical support for grid stability.展开更多
The high proportion of uncertain distributed power sources and the access to large-scale random electric vehicle(EV)charging resources further aggravate the voltage fluctuation of the distribution network,and the exis...The high proportion of uncertain distributed power sources and the access to large-scale random electric vehicle(EV)charging resources further aggravate the voltage fluctuation of the distribution network,and the existing research has not deeply explored the EV active-reactive synergistic regulating characteristics,and failed to realize themulti-timescale synergistic control with other regulatingmeans,For this reason,this paper proposes amultilevel linkage coordinated optimization strategy to reduce the voltage deviation of the distribution network.Firstly,a capacitor bank reactive power compensation voltage control model and a distributed photovoltaic(PV)activereactive power regulationmodel are established.Additionally,an external characteristicmodel of EVactive-reactive power regulation is developed considering the four-quadrant operational characteristics of the EVcharger.Amultiobjective optimization model of the distribution network is then constructed considering the time-series coupling constraints of multiple types of voltage regulators.A multi-timescale control strategy is proposed by considering the impact of voltage regulators on active-reactive EV energy consumption and PV energy consumption.Then,a four-stage voltage control optimization strategy is proposed for various types of voltage regulators with multiple time scales.Themulti-objective optimization is solved with the improvedDrosophila algorithmto realize the power fluctuation control of the distribution network and themulti-stage voltage control optimization.Simulation results validate that the proposed voltage control optimization strategy achieves the coordinated control of decentralized voltage control resources in the distribution network.It effectively reduces the voltage deviation of the distribution network while ensuring the energy demand of EV users and enhancing the stability and economic efficiency of the distribution network.展开更多
BACKGROUND Inadequate glycemic control in patients with type 2 diabetes(T2DM)is a major public health problem and a significant risk factor for the progression of diabetic complications.AIM To evaluate the effects of ...BACKGROUND Inadequate glycemic control in patients with type 2 diabetes(T2DM)is a major public health problem and a significant risk factor for the progression of diabetic complications.AIM To evaluate the effects of intensive and supportive glycemic management strategies over a 12-month period in individuals with T2DM with glycated hemoglobin(HbA1c)≥10%and varying backgrounds of glycemic control.METHODS This prospective observational study investigated glycemic control in patients with poorly controlled T2DM over 12 months.Participants were categorized into four groups based on prior glycemic history:Newly diagnosed,previously well controlled with recent worsening,previously off-target but now worsening,and HbA1c consistently above 10%.HbA1c levels were monitored quarterly,and patients received medical,educational,and dietary support as needed.The analysis focused on the success rates of good glycemic control and the associated factors within each group.RESULTS The study showed significant improvements in HbA1c levels in all participants.The most significant improvement was observed in individuals newly diagnosed with diabetes:65%achieved an HbA1c target of≤7%.The results varied between participants with different glycemic control histories,followed by decreasing success rates:39%in participants with previously good glycemic control,21%in participants whose glycemic control had deteriorated compared to before,and only 10%in participants with persistently poor control,with mean HbA1c levels of 6.3%,7.7%,8.2%,and 9.7%,respectively.After one year,65.2%of the“newly diagnosed patients”,39.3%in the“previously controlled group”,21.9%in the“previously off-target but now worsened'”group and 10%in the“poorly controlled from the start”group had achieved HbA1c levels of 7 and below.CONCLUSION In poorly controlled diabetes,the rate at which treatment goals are achieved is associated with the glycemic background characteristics,emphasizing the need for tailored strategies.Therefore,different and comprehensive treatment approaches are needed for patients with persistent uncontrolled diabetes.展开更多
Pearl millet, Pennisetum glaucum (Leeke) R. Br, is the main cereal crop in Niger. This crop is seriously attacked by the millet Head miner (MHM), Heliocheilus albipunctella (de Joannis) (Lepidoptera, Noctuidae) causin...Pearl millet, Pennisetum glaucum (Leeke) R. Br, is the main cereal crop in Niger. This crop is seriously attacked by the millet Head miner (MHM), Heliocheilus albipunctella (de Joannis) (Lepidoptera, Noctuidae) causing significant yield losses. This study to optimize biological control of this pest was carried out in Niger in the laboratory and in a farming environment. In the laboratory, the larval paralysis and emergence of the parasitoid Habrobracon hebetor Say (Hymenoptera: Braconidae) were compared between release jute bags, plastic boxes and cardboard boxes. In a farming environment, direct releases were carried out with plastic boxes and releases with jute bags in 12 villages of the Maradi region during the cropping seasons of 2021 and 2022. The results indicated that 25 larvae of Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) in the boxes were all paralyzed by 2 females of H. hebetor within 7 hours 30 minutes. The emergence of adults began on the 7th day after the beginning of the experiment for a period of two weeks and three weeks respectively in the boxes and jute bags. The production varied from 107.08 to 110.17 parasitoids and was comparable between the Jute bags, plastic boxes and cardboard boxes. In Farmers’ fields, the parasitoid release with the two methods caused the parasitism rates that varied from 64.32 to 66.52% depending on the year but in 2022 the rate of parasitism was higher in the fields with direct releases using plastic boxes (72.66%) compared to those released with jute bags (56.35%). Plastic boxes and cardboard boxes can be used for the production of the H. hebetor parasitoids. These results can be recommended to the cottage industries in the Sahel in order to improve the production and release methods of H. hebetor and make them more adapted to farmers’ fields.展开更多
Introduction: High blood pressure is a major public health issue affecting 1.28 billion people worldwide in 2019, making it the leading chronic disease. Blood pressure control remains particularly difficult, especiall...Introduction: High blood pressure is a major public health issue affecting 1.28 billion people worldwide in 2019, making it the leading chronic disease. Blood pressure control remains particularly difficult, especially in sub-Saharan Africa. The objective of our study was to identify factors associated with poor blood pressure control in hypertensive patients followed up at the cardiology department of the Dalal Jamm National Hospital. Patients and methods: This was a retrospective, descriptive and analytical, single-center cross-sectional study conducted over a 12-month period from January 1, 2021 to December 31, 2021, involving hypertensive patients followed for at least 3 months. The parameters studied were sociodemographic data, cardiovascular risk factors associated with high blood pressure, clinical signs, therapeutic compliance, therapeutic aspects, blood pressure control, and factors associated with poor control. The data were analyzed using RStudio 4.6 software. Result: High blood pressure represented 26.6% (n = 722) of the reasons for consultations and 109 patients were included in the study. We found a female predominance with a sex ratio of 0.48. The mean age of the population was 61.9 years ± 12. The predominant age group was 60 - 80 years representing 67% (n = 73) of patients. Diabetics represented 30% (n = 33) all type 2, 40% (n = 43) had dyslipidemia, 58 women had reached menopause. Sedentary lifestyle was found in 76% of patients, 61% (n = 67) had a family history of hypertension. In addition, 43.5% of the population studied had more than 3 risk factors in addition to hypertension. Patient follow-up was irregular in 21.1%. The mean systolic blood pressure was 162.4 ± 21 mm Hg and diastolic 96.16 ± 13.6 mm Hg. The mean heart rate was 77.84 ± 18.01 beats per minute. Dieulafoy signs were reported in 58% of patients. The low-sodium diet was respected by 77% of patients. Dual therapy was the most prescribed protocol with 42% (n = 46). Among the complications, heart failure was the most frequent (49%), followed by stroke (30%). The Girerd test was applied to assess therapeutic compliance, 30% of patients were good adherents, 43.5% had a minimal problem of adherence and 26.5% were not at all adherent. The blood pressure control rate was 53.20%. In bivariate analysis, sedentary lifestyle (p Conclusion: The management of high blood pressure encounters significant difficulties, resulting in inadequate control of blood pressure figures. Blood pressure was not controlled in almost half of the patients. The factor of poor blood pressure control identified was therapeutic non-compliance. It is imperative to make care more accessible and promote therapeutic education.展开更多
Malaria is a potentially lethal disease caused by parasites of the Plasmodium genus, transmitted to humans through the bite of infected female mosquitoes, primarily Anopheles. To control this disease, various strategi...Malaria is a potentially lethal disease caused by parasites of the Plasmodium genus, transmitted to humans through the bite of infected female mosquitoes, primarily Anopheles. To control this disease, various strategies are implemented, including biological control, which targets the vectors of the parasite. This approach uses biological agents such as entomopathogenic fungi, including Metarhizium pingshaense, a fungus capable of causing lethal infections in mosquitoes. The production of Metarhizium pingshaense is still limited in Burkina Faso, and local cultivation of this fungus could help fill this gap. A study was conducted to identify optimal local substrates that promote its growth. Indeed, after gathering information on the dietary habits of populations in Bobo-Dioulasso and Bama, three potential substrates were selected: rice, cornmeal dough (MFL), and beans. These substrates were inoculated with two strains of Metarhizium pingshaense (S10 and S26) to assess their ability to support fungal growth and their effectiveness. Experimental results showed that MFL and bean substrates favored optimal growth of Metarhizium pingshaense, with growths of 1.91 cm and 2.13 cm after 8 days, compared to 1.83 cm on a standard media (PDA). In terms of virulence, S26 strain caused 60% mosquito mortality on both the bean and PDA media, while S10 strain induced mortalities of 50% for bean and 62% for PDA.展开更多
Dose estimation and quality control in computed tomography (CT) scanners are useful in controlling the dose of radiation given to patients while tests are carried out. The study was performed in a 16-slice Computed To...Dose estimation and quality control in computed tomography (CT) scanners are useful in controlling the dose of radiation given to patients while tests are carried out. The study was performed in a 16-slice Computed Tomography (CT) system of LightSpeed RT16 Xtra CT scanner. Quality control was done using a vendor-provided QA Phantom, and the six aspects of image quality were measured. For CT dosimetry, Computed Tomography Dose index volume (CTDIvol) was performed using Computed Tomography Dose Index (CTDI) Phantom. CTDI Phantom consists of three parts: Pediatric Head, Adult Head, and Adult Body Phantom. A 10 cm long pencil ion chamber DCT-10 was used to measure the dose at different positions inside the CTDI Phantom. Data were collected using MagicMax Universal software. For dose estimation of the CTDIvol Report of AAPM Task Group, 96 and 111 formalisms were used. For Pediatric Head, Adult Head, and Adult Body Phantom the measured CIDIvol was 61.04 mGy, 48.11 mGy, and 18.08 mGy respectively. The study has shown deviations of 7%, 15%, and 19% between estimated and console-displayed doses for Pediatric Head, Adult Head, and Adult Body scan techniques respectively. The six aspects of image quality measured by QA Phantom were found to be compatible with the specifications of the machine and CTDIvol measured by CTDI Phantom were found within a tolerance limit of ±20%. Hence, the QC and dosimetry of the mentioned machine are within the limit.展开更多
Enhancing the stability and performance of practical control systems in the presence of nonlinearity,time delay,and uncertainty remains a significant challenge.Particularly,a class of strict-feedback nonlinear uncerta...Enhancing the stability and performance of practical control systems in the presence of nonlinearity,time delay,and uncertainty remains a significant challenge.Particularly,a class of strict-feedback nonlinear uncertain systems characterized by unknown control directions and time-varying input delay lacks comprehensive solutions.In this paper,we propose an observerbased adaptive tracking controller to address this gap.Neural networks are utilized to handle uncertainty,and a unique coordinate transformation is employed to untangle the coupling between input delay and unknown control directions.Subsequently,a new auxiliary signal counters the impact of time-varying input delay,while a Nussbaum function is introduced to solve the problem of unknown control directions.The leverage of an advanced dynamic surface control technique avoids the“complexity explosion”and reduces boundary layer errors.Synthesizing these techniques ensures that all the closed-loop signals are semi-globally uniformly ultimately bounded(SGUUB),and the tracking error converges to a small region around the origin by selecting suitable parameters.Simulation examples are provided to demonstrate the feasibility of the proposed approach.展开更多
Graphene platelets(GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams.Further bonding piezoelectric actuator and sensor layers on ...Graphene platelets(GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams.Further bonding piezoelectric actuator and sensor layers on the surfaces of GPLs-reinforced metal foam beams enables active vibration control,greatly expanding their applications in the aerospace industry.For the first time,this paper investigates the vibration characteristics and active vibration control of GPLs-reinforced metal foam beams with surfacebonded piezoelectric layers.The constant velocity feedback scheme is used to design the closed-loop controller including piezoelectric actuators and sensors.The effects of the GPLs on the linear and nonlinear free vibrations of the beams are numerically studied.The Newmark-βmethod combined with Newton's iteration technique is used to calculate the nonlinear responses of the beams under different load forms including harmonic loads,impact loads,and moving loads.Additionally,special attention is given to the vibration reduction performance of the velocity feedback control on the responses of the beam.展开更多
In order to enhance the control performance of piezo-positioning system,the influence of hysteresis characteristics and its compensation method are studied.Hammerstein model is used to represent the dynamic hysteresis...In order to enhance the control performance of piezo-positioning system,the influence of hysteresis characteristics and its compensation method are studied.Hammerstein model is used to represent the dynamic hysteresis nonlinear characteristics of piezo-positioning actuator.The static nonlinear part and dynamic linear part of the Hammerstein model are represented by models obtained through the Prandtl-Ishlinskii(PI)model and Hankel matrix system identification method,respectively.This model demonstrates good generalization capability for typical input frequencies below 200 Hz.A sliding mode inverse compensation tracking control strategy based on P-I inverse model and integral augmentation is proposed.Experimental results show that compared with PID inverse compensation control and sliding mode control without inverse compensation,the sliding mode inverse compensation control has a more ideal step response and no overshoot,moreover,the settling time is only 6.2 ms.In the frequency domain,the system closed-loop tracking bandwidth reaches 119.9 Hz,and the disturbance rejection bandwidth reaches 86.2 Hz.The proposed control strategy can effectively compensate the hysteresis nonlinearity,and improve the tracking accuracy and antidisturbance capability of piezo-positioning system.展开更多
OBJECTIVE:In recent years,the number of clinical research reports on acupuncture and manipulation for the treatment of greater occipital neuralgia has gradually increased,but the quality is uneven.There is currently n...OBJECTIVE:In recent years,the number of clinical research reports on acupuncture and manipulation for the treatment of greater occipital neuralgia has gradually increased,but the quality is uneven.There is currently no literature evaluating the quality of published reports,which is not conducive to the promotion of clinical use of these therapies.Therefore,this article assessed the reporting quality of randomized controlled trials on acupuncture and manipulation for greater occipital neuralgia.METHODS:Cochrane Library,PubMed,Web of Science,Embase,China National Knowledge Infrastructure(CNKI),VIP,WanFang Data,and Chinese BioMedical Literature Database(CBM)from inception to May 20,2024 were searched.The reporting quality of included randomized controlled trials was independently evaluated by two investigators using the CONSORT statement,STRICTA checklist,and Cochrane bias of risk assessment tool.A third investigator resolved any disagreement.RESULTS:A total of 62 articles were included.Based on the CONSORT statement,59.46%(22/37)of all entries had a reporting rate of less than 50%,mainly including“Identification as a randomized trial in the title(1/62,1.61%),”“How sample size was determined(7/62,11.29%),”“Implementation(1/62,1.61%),”“Blinding(1/62,1.61%),”and“Reports of Funding(4/62,6.45%).”According to the STRICTA checklist,29.41%(5/17)of all entries had a reporting rate of less than 50%,mainly including“Details of other interventions(7/58,12.07%),”“Setting and context of treatment(0/58,0%),”and“Description of participating acupuncturists(0/58,0%).”CONCLUSION:The reporting quality of randomized controlled trials on acupuncture and manipulation therapy for greater occipital neuralgia remains low.Future researchers need to make greater efforts to strictly adhere to the CONSORT statement and STRICTA checklist during trial design,implementation,and reporting.This will facilitate the standardization of research in this field and enhance the reliability and reproducibility of the research results.展开更多
As Model-Based Systems Engineering(MBSE)was applied to the Electric Multiple Unit(EMU)braking system control logic,a preliminary exploration was conducted for bullet train braking system control logic research using a...As Model-Based Systems Engineering(MBSE)was applied to the Electric Multiple Unit(EMU)braking system control logic,a preliminary exploration was conducted for bullet train braking system control logic research using an MBSE practice framework.The framework mainly includes the requirement analysis phase,functional analysis phase,and design phase.Systems Modeling Language(SysML)was used as the modeling language,and Cameo Systems Modeler(CSM)was employed as the modeling tool.By integrating the EMU braking system control logic and utilizing a top-down design approach,the implementation of MBSE in the bullet train braking system was analyzed and studied.The results show that,according to the MBSE practice framework,a unified description of the requirement analysis,functional analysis,and design synthesis of the EMU braking system control logic can be achieved.Additionally,the correlation and traceability between models can be established.展开更多
基金funded by The National Key R&D Program of China(2016YFB0101402).
文摘The water medium hydraulic retarder is the latest type of auxiliary braking device and has the characteristics of high power density,large braking torque,and compact structure.During traveling,this device can convert the kinetic energy of a vehicle to the heat energy of the cooling liquid and replace the service brake under non-emergency braking conditions.With regard to the constant-speed function of the water medium hydraulic retarder,this study designs a controller based on the neural network proportional-integral-derivative(PID)algorithm to achieve the steady traveling of the vehicle at constant velocity during a downhill course by controlling the filling ratio of the water medium hydraulic retarder.To validate the algorithm’s effectiveness,the dynamic model of the heavy-duty vehicle in the downhill process and the physical model of the water medium hydraulic retarder are developed.Three operating conditions,including a fixed slope,step-changing slope,and continuous changing slope,are set,and a simulation test is carried out in the MATLAB/Simulink environment.The neural network PID algorithm has better adaptability in controlling than the traditional PID algorithm.Thus,it controls the water medium hydraulic retarder such that the braking requirements of heavy-duty vehicles under a changing slope working condi-tion are satisfied,and it performs constant-speed control when the vehicle travels downhill.Therefore,the proposed control method can significantly improve the safety of road traffic.
文摘Advances in software and hardware technologies have facilitated the production of quadrotor unmanned aerial vehicles(UAVs).Nowadays,people actively use quadrotor UAVs in essential missions such as search and rescue,counter-terrorism,firefighting,surveillance,and cargo transportation.While performing these tasks,quadrotors must operate in noisy environments.Therefore,a robust controller design that can control the altitude and attitude of the quadrotor in noisy environments is of great importance.Many researchers have focused only on white Gaussian noise in their studies,whereas researchers need to consider the effects of all colored noises during the operation of the quadrotor.This study aims to design a robust controller that is resistant to all colored noises.Firstly,a nonlinear quadrotormodel was created with MATLAB.Then,a backstepping controller resistant to colored noises was designed.Thedesigned backstepping controller was tested under Gaussian white,pink,brown,blue,and purple noises.PID and Lyapunov-based controller designswere also carried out,and their time responses(rise time,overshoot,settling time)were compared with those of the backstepping controller.In the simulations,time was in seconds,altitude was in meters,and roll,pitch,and yaw references were in radians.Rise and settling time values were in seconds,and overshoot value was in percent.When the obtained values are examined,simulations prove that the proposed backstepping controller has the least overshoot and the shortest settling time under all noise types.
基金supported by the State Grid Corporation of China Science and Technology Project,grant number 52270723000900K.
文摘The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.
基金National Natural Science Foundation of China(32201491)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)The authors extend their appreciation to the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-1101-02”.
文摘Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.
基金supported by the Science and Technology Project of the State Grid Corporation of China,Grant number 5700-202223189A-1-1-ZN.
文摘Renewable Energy Systems(RES)provide a sustainable solution to climate warming and environmental pollution by enhancing stability and reliability through status acquisition and analysis on cloud platforms and intelligent processing on edge servers(ES).However,securely distributing encrypted data stored in the cloud to terminals that meet decryption requirements has become a prominent research topic.Additionally,managing attributes,including addition,deletion,and modification,is a crucial issue in the access control scheme for RES.To address these security concerns,a trust-based ciphertext-policy attribute-based encryption(CP-ABE)device access control scheme is proposed for RES(TB-CP-ABE).This scheme effectivelymanages the distribution and control of encrypted data on the cloud through robust attribute key management.By introducing trust management mechanisms and outsourced decryption technology,the ES system can effectively assess and manage the trust worthiness of terminal devices,ensuring that only trusted devices can participate in data exchange and access sensitive information.Besides,the ES system dynamically evaluates trust scores to set decryption trust thresholds,thereby regulating device data access permissions and enhancing the system’s security.To validate the security of the proposed TB-CP-ABE against chosen plaintext attacks,a comprehensive formal security analysis is conducted using the widely accepted random oraclemodel under the decisional q-Bilinear Diffie-Hellman Exponent(q-BDHE)assumption.Finally,comparative analysis with other schemes demonstrates that the TB-CP-ABE scheme cuts energy/communication costs by 43%,and scaleswell with rising terminals,maintaining average latency below 50ms,ensuring real-time service feasibility.The proposed scheme not only provides newinsights for the secure management of RES but also lays a foundation for future secure energy solutions.
基金supported in part by Natural Science Foundation of Jiangsu Province under Grant BK20230255Natural Science Foundation of Shandong Province under Grant ZR2023QE281.
文摘The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract.
文摘It’s possible for malicious operators to seize hold of electrical control systems, for instance, the engine control unit of driverless vehicles, from various vectors, e.g. autonomic control system, remote vehicle access, or human drivers. To mitigate potential risks, this paper provides the inauguration study by proposing a theoretical framework in the physical, human and cyber triad. Its goal is to, at each time point, detect adversary control behaviors and protect control systems against malicious operations via integrating a variety of methods. This paper only proposes a theoretical framework which tries to indicate possible threats. With the support of the framework, the security system can lightly reduce the risk. The development and implementation of the system are out of scope.
文摘In this paper, we proposed an output voltage stabilization of a DC-DC Zeta converter using hybrid control. We modeled the Zeta converter under continuous conduction mode operation. We derived a switching control law that brings the output voltage to the desired level. Due to infinite switching occurring at the desired level, we enhanced the switching control law by allowing a sizeable output voltage ripple. We derived mathematical models that allow one to choose the desired switching frequency. In practice, the existence of the non-ideal properties of the Zeta converter results in steady-state output voltage error. By analyzing the power loss in the zeta converter, we proposed an improved switching control law that eliminates the steady-state output voltage error. The effectiveness of the proposed method is illustrated with simulation results.
基金received funding from the Postgraduate Research&Practice Innovation Program of Jiangsu Province(SJCX23_1633)2023 University Student Innovation and Entrepreneurship Training Program(202311463009Z)+1 种基金Changzhou Science and Technology Support Project(CE20235045)Open Project of Jiangsu Key Laboratory of Power Transmission&Distribution Equipment Technology(2021JSSPD12).
文摘Uneven power distribution,transient voltage,and frequency deviations are observed in the photovoltaic storage hybrid inverter during the switching between grid-connected and island modes.In response to these issues,this paper proposes a grid-connected/island switching control strategy for photovoltaic storage hybrid inverters based on the modified chimpanzee optimization algorithm.The proposed strategy incorporates coupling compensation and power differentiation elements based on the traditional droop control.Then,it combines the angular frequency and voltage amplitude adjustments provided by the phase-locked loop-free pre-synchronization control strategy.Precise pre-synchronization is achieved by regulating the virtual current to zero and aligning the photovoltaic storage hybrid inverter with the grid voltage.Additionally,two novel operators,learning and emotional behaviors are introduced to enhance the optimization precision of the chimpanzee algorithm.These operators ensure high-precision and high-reliability optimization of the droop control parameters for photovoltaic storage hybrid inverters.A Simulink model was constructed for simulation analysis,which validated the optimized control strategy’s ability to evenly distribute power under load transients.This strategy effectively mitigated transient voltage and current surges during mode transitions.Consequently,seamless and efficient switching between gridconnected and island modes was achieved for the photovoltaic storage hybrid inverter.The enhanced energy utilization efficiency,in turn,offers robust technical support for grid stability.
基金funded by the State Grid Corporation Science and Technology Project(5108-202218280A-2-391-XG).
文摘The high proportion of uncertain distributed power sources and the access to large-scale random electric vehicle(EV)charging resources further aggravate the voltage fluctuation of the distribution network,and the existing research has not deeply explored the EV active-reactive synergistic regulating characteristics,and failed to realize themulti-timescale synergistic control with other regulatingmeans,For this reason,this paper proposes amultilevel linkage coordinated optimization strategy to reduce the voltage deviation of the distribution network.Firstly,a capacitor bank reactive power compensation voltage control model and a distributed photovoltaic(PV)activereactive power regulationmodel are established.Additionally,an external characteristicmodel of EVactive-reactive power regulation is developed considering the four-quadrant operational characteristics of the EVcharger.Amultiobjective optimization model of the distribution network is then constructed considering the time-series coupling constraints of multiple types of voltage regulators.A multi-timescale control strategy is proposed by considering the impact of voltage regulators on active-reactive EV energy consumption and PV energy consumption.Then,a four-stage voltage control optimization strategy is proposed for various types of voltage regulators with multiple time scales.Themulti-objective optimization is solved with the improvedDrosophila algorithmto realize the power fluctuation control of the distribution network and themulti-stage voltage control optimization.Simulation results validate that the proposed voltage control optimization strategy achieves the coordinated control of decentralized voltage control resources in the distribution network.It effectively reduces the voltage deviation of the distribution network while ensuring the energy demand of EV users and enhancing the stability and economic efficiency of the distribution network.
文摘BACKGROUND Inadequate glycemic control in patients with type 2 diabetes(T2DM)is a major public health problem and a significant risk factor for the progression of diabetic complications.AIM To evaluate the effects of intensive and supportive glycemic management strategies over a 12-month period in individuals with T2DM with glycated hemoglobin(HbA1c)≥10%and varying backgrounds of glycemic control.METHODS This prospective observational study investigated glycemic control in patients with poorly controlled T2DM over 12 months.Participants were categorized into four groups based on prior glycemic history:Newly diagnosed,previously well controlled with recent worsening,previously off-target but now worsening,and HbA1c consistently above 10%.HbA1c levels were monitored quarterly,and patients received medical,educational,and dietary support as needed.The analysis focused on the success rates of good glycemic control and the associated factors within each group.RESULTS The study showed significant improvements in HbA1c levels in all participants.The most significant improvement was observed in individuals newly diagnosed with diabetes:65%achieved an HbA1c target of≤7%.The results varied between participants with different glycemic control histories,followed by decreasing success rates:39%in participants with previously good glycemic control,21%in participants whose glycemic control had deteriorated compared to before,and only 10%in participants with persistently poor control,with mean HbA1c levels of 6.3%,7.7%,8.2%,and 9.7%,respectively.After one year,65.2%of the“newly diagnosed patients”,39.3%in the“previously controlled group”,21.9%in the“previously off-target but now worsened'”group and 10%in the“poorly controlled from the start”group had achieved HbA1c levels of 7 and below.CONCLUSION In poorly controlled diabetes,the rate at which treatment goals are achieved is associated with the glycemic background characteristics,emphasizing the need for tailored strategies.Therefore,different and comprehensive treatment approaches are needed for patients with persistent uncontrolled diabetes.
文摘Pearl millet, Pennisetum glaucum (Leeke) R. Br, is the main cereal crop in Niger. This crop is seriously attacked by the millet Head miner (MHM), Heliocheilus albipunctella (de Joannis) (Lepidoptera, Noctuidae) causing significant yield losses. This study to optimize biological control of this pest was carried out in Niger in the laboratory and in a farming environment. In the laboratory, the larval paralysis and emergence of the parasitoid Habrobracon hebetor Say (Hymenoptera: Braconidae) were compared between release jute bags, plastic boxes and cardboard boxes. In a farming environment, direct releases were carried out with plastic boxes and releases with jute bags in 12 villages of the Maradi region during the cropping seasons of 2021 and 2022. The results indicated that 25 larvae of Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) in the boxes were all paralyzed by 2 females of H. hebetor within 7 hours 30 minutes. The emergence of adults began on the 7th day after the beginning of the experiment for a period of two weeks and three weeks respectively in the boxes and jute bags. The production varied from 107.08 to 110.17 parasitoids and was comparable between the Jute bags, plastic boxes and cardboard boxes. In Farmers’ fields, the parasitoid release with the two methods caused the parasitism rates that varied from 64.32 to 66.52% depending on the year but in 2022 the rate of parasitism was higher in the fields with direct releases using plastic boxes (72.66%) compared to those released with jute bags (56.35%). Plastic boxes and cardboard boxes can be used for the production of the H. hebetor parasitoids. These results can be recommended to the cottage industries in the Sahel in order to improve the production and release methods of H. hebetor and make them more adapted to farmers’ fields.
文摘Introduction: High blood pressure is a major public health issue affecting 1.28 billion people worldwide in 2019, making it the leading chronic disease. Blood pressure control remains particularly difficult, especially in sub-Saharan Africa. The objective of our study was to identify factors associated with poor blood pressure control in hypertensive patients followed up at the cardiology department of the Dalal Jamm National Hospital. Patients and methods: This was a retrospective, descriptive and analytical, single-center cross-sectional study conducted over a 12-month period from January 1, 2021 to December 31, 2021, involving hypertensive patients followed for at least 3 months. The parameters studied were sociodemographic data, cardiovascular risk factors associated with high blood pressure, clinical signs, therapeutic compliance, therapeutic aspects, blood pressure control, and factors associated with poor control. The data were analyzed using RStudio 4.6 software. Result: High blood pressure represented 26.6% (n = 722) of the reasons for consultations and 109 patients were included in the study. We found a female predominance with a sex ratio of 0.48. The mean age of the population was 61.9 years ± 12. The predominant age group was 60 - 80 years representing 67% (n = 73) of patients. Diabetics represented 30% (n = 33) all type 2, 40% (n = 43) had dyslipidemia, 58 women had reached menopause. Sedentary lifestyle was found in 76% of patients, 61% (n = 67) had a family history of hypertension. In addition, 43.5% of the population studied had more than 3 risk factors in addition to hypertension. Patient follow-up was irregular in 21.1%. The mean systolic blood pressure was 162.4 ± 21 mm Hg and diastolic 96.16 ± 13.6 mm Hg. The mean heart rate was 77.84 ± 18.01 beats per minute. Dieulafoy signs were reported in 58% of patients. The low-sodium diet was respected by 77% of patients. Dual therapy was the most prescribed protocol with 42% (n = 46). Among the complications, heart failure was the most frequent (49%), followed by stroke (30%). The Girerd test was applied to assess therapeutic compliance, 30% of patients were good adherents, 43.5% had a minimal problem of adherence and 26.5% were not at all adherent. The blood pressure control rate was 53.20%. In bivariate analysis, sedentary lifestyle (p Conclusion: The management of high blood pressure encounters significant difficulties, resulting in inadequate control of blood pressure figures. Blood pressure was not controlled in almost half of the patients. The factor of poor blood pressure control identified was therapeutic non-compliance. It is imperative to make care more accessible and promote therapeutic education.
文摘Malaria is a potentially lethal disease caused by parasites of the Plasmodium genus, transmitted to humans through the bite of infected female mosquitoes, primarily Anopheles. To control this disease, various strategies are implemented, including biological control, which targets the vectors of the parasite. This approach uses biological agents such as entomopathogenic fungi, including Metarhizium pingshaense, a fungus capable of causing lethal infections in mosquitoes. The production of Metarhizium pingshaense is still limited in Burkina Faso, and local cultivation of this fungus could help fill this gap. A study was conducted to identify optimal local substrates that promote its growth. Indeed, after gathering information on the dietary habits of populations in Bobo-Dioulasso and Bama, three potential substrates were selected: rice, cornmeal dough (MFL), and beans. These substrates were inoculated with two strains of Metarhizium pingshaense (S10 and S26) to assess their ability to support fungal growth and their effectiveness. Experimental results showed that MFL and bean substrates favored optimal growth of Metarhizium pingshaense, with growths of 1.91 cm and 2.13 cm after 8 days, compared to 1.83 cm on a standard media (PDA). In terms of virulence, S26 strain caused 60% mosquito mortality on both the bean and PDA media, while S10 strain induced mortalities of 50% for bean and 62% for PDA.
文摘Dose estimation and quality control in computed tomography (CT) scanners are useful in controlling the dose of radiation given to patients while tests are carried out. The study was performed in a 16-slice Computed Tomography (CT) system of LightSpeed RT16 Xtra CT scanner. Quality control was done using a vendor-provided QA Phantom, and the six aspects of image quality were measured. For CT dosimetry, Computed Tomography Dose index volume (CTDIvol) was performed using Computed Tomography Dose Index (CTDI) Phantom. CTDI Phantom consists of three parts: Pediatric Head, Adult Head, and Adult Body Phantom. A 10 cm long pencil ion chamber DCT-10 was used to measure the dose at different positions inside the CTDI Phantom. Data were collected using MagicMax Universal software. For dose estimation of the CTDIvol Report of AAPM Task Group, 96 and 111 formalisms were used. For Pediatric Head, Adult Head, and Adult Body Phantom the measured CIDIvol was 61.04 mGy, 48.11 mGy, and 18.08 mGy respectively. The study has shown deviations of 7%, 15%, and 19% between estimated and console-displayed doses for Pediatric Head, Adult Head, and Adult Body scan techniques respectively. The six aspects of image quality measured by QA Phantom were found to be compatible with the specifications of the machine and CTDIvol measured by CTDI Phantom were found within a tolerance limit of ±20%. Hence, the QC and dosimetry of the mentioned machine are within the limit.
基金National Natural Science Foundation of China(62373102)Jiangsu Natural Science Foundation(BK20221455)Anhui Provincial Key Research and Development Project(2022i01020013)。
文摘Enhancing the stability and performance of practical control systems in the presence of nonlinearity,time delay,and uncertainty remains a significant challenge.Particularly,a class of strict-feedback nonlinear uncertain systems characterized by unknown control directions and time-varying input delay lacks comprehensive solutions.In this paper,we propose an observerbased adaptive tracking controller to address this gap.Neural networks are utilized to handle uncertainty,and a unique coordinate transformation is employed to untangle the coupling between input delay and unknown control directions.Subsequently,a new auxiliary signal counters the impact of time-varying input delay,while a Nussbaum function is introduced to solve the problem of unknown control directions.The leverage of an advanced dynamic surface control technique avoids the“complexity explosion”and reduces boundary layer errors.Synthesizing these techniques ensures that all the closed-loop signals are semi-globally uniformly ultimately bounded(SGUUB),and the tracking error converges to a small region around the origin by selecting suitable parameters.Simulation examples are provided to demonstrate the feasibility of the proposed approach.
基金Project supported by the National Natural Science Foundation of China(Nos.12102015 and 12472003)the R&D Program of Beijing Municipal Education Commission of China(No.KM202110005030)。
文摘Graphene platelets(GPLs)-reinforced metal foam structures enhance the mechanical properties while maintaining the lightweight characteristics of metal foams.Further bonding piezoelectric actuator and sensor layers on the surfaces of GPLs-reinforced metal foam beams enables active vibration control,greatly expanding their applications in the aerospace industry.For the first time,this paper investigates the vibration characteristics and active vibration control of GPLs-reinforced metal foam beams with surfacebonded piezoelectric layers.The constant velocity feedback scheme is used to design the closed-loop controller including piezoelectric actuators and sensors.The effects of the GPLs on the linear and nonlinear free vibrations of the beams are numerically studied.The Newmark-βmethod combined with Newton's iteration technique is used to calculate the nonlinear responses of the beams under different load forms including harmonic loads,impact loads,and moving loads.Additionally,special attention is given to the vibration reduction performance of the velocity feedback control on the responses of the beam.
文摘In order to enhance the control performance of piezo-positioning system,the influence of hysteresis characteristics and its compensation method are studied.Hammerstein model is used to represent the dynamic hysteresis nonlinear characteristics of piezo-positioning actuator.The static nonlinear part and dynamic linear part of the Hammerstein model are represented by models obtained through the Prandtl-Ishlinskii(PI)model and Hankel matrix system identification method,respectively.This model demonstrates good generalization capability for typical input frequencies below 200 Hz.A sliding mode inverse compensation tracking control strategy based on P-I inverse model and integral augmentation is proposed.Experimental results show that compared with PID inverse compensation control and sliding mode control without inverse compensation,the sliding mode inverse compensation control has a more ideal step response and no overshoot,moreover,the settling time is only 6.2 ms.In the frequency domain,the system closed-loop tracking bandwidth reaches 119.9 Hz,and the disturbance rejection bandwidth reaches 86.2 Hz.The proposed control strategy can effectively compensate the hysteresis nonlinearity,and improve the tracking accuracy and antidisturbance capability of piezo-positioning system.
文摘OBJECTIVE:In recent years,the number of clinical research reports on acupuncture and manipulation for the treatment of greater occipital neuralgia has gradually increased,but the quality is uneven.There is currently no literature evaluating the quality of published reports,which is not conducive to the promotion of clinical use of these therapies.Therefore,this article assessed the reporting quality of randomized controlled trials on acupuncture and manipulation for greater occipital neuralgia.METHODS:Cochrane Library,PubMed,Web of Science,Embase,China National Knowledge Infrastructure(CNKI),VIP,WanFang Data,and Chinese BioMedical Literature Database(CBM)from inception to May 20,2024 were searched.The reporting quality of included randomized controlled trials was independently evaluated by two investigators using the CONSORT statement,STRICTA checklist,and Cochrane bias of risk assessment tool.A third investigator resolved any disagreement.RESULTS:A total of 62 articles were included.Based on the CONSORT statement,59.46%(22/37)of all entries had a reporting rate of less than 50%,mainly including“Identification as a randomized trial in the title(1/62,1.61%),”“How sample size was determined(7/62,11.29%),”“Implementation(1/62,1.61%),”“Blinding(1/62,1.61%),”and“Reports of Funding(4/62,6.45%).”According to the STRICTA checklist,29.41%(5/17)of all entries had a reporting rate of less than 50%,mainly including“Details of other interventions(7/58,12.07%),”“Setting and context of treatment(0/58,0%),”and“Description of participating acupuncturists(0/58,0%).”CONCLUSION:The reporting quality of randomized controlled trials on acupuncture and manipulation therapy for greater occipital neuralgia remains low.Future researchers need to make greater efforts to strictly adhere to the CONSORT statement and STRICTA checklist during trial design,implementation,and reporting.This will facilitate the standardization of research in this field and enhance the reliability and reproducibility of the research results.
文摘As Model-Based Systems Engineering(MBSE)was applied to the Electric Multiple Unit(EMU)braking system control logic,a preliminary exploration was conducted for bullet train braking system control logic research using an MBSE practice framework.The framework mainly includes the requirement analysis phase,functional analysis phase,and design phase.Systems Modeling Language(SysML)was used as the modeling language,and Cameo Systems Modeler(CSM)was employed as the modeling tool.By integrating the EMU braking system control logic and utilizing a top-down design approach,the implementation of MBSE in the bullet train braking system was analyzed and studied.The results show that,according to the MBSE practice framework,a unified description of the requirement analysis,functional analysis,and design synthesis of the EMU braking system control logic can be achieved.Additionally,the correlation and traceability between models can be established.
