Background Both medication and non-medication therapies are effective approaches to control blood pressure (BP) in hypertension patients.However,the association of joint changes in antihypertensive medication use and ...Background Both medication and non-medication therapies are effective approaches to control blood pressure (BP) in hypertension patients.However,the association of joint changes in antihypertensive medication use and healthy lifestyle index (HLI)with BP control among hypertension patients is seldom reported,which needs to provide more evidence by prospective intervention studies.We examined the association of antihypertensive medication use and HLI with BP control among employees with hypertension in China based on a workplace-based multicomponent intervention program.Methods Between January 2013 and December 2014,a cluster randomized clinical trial of a workplace-based multicomponent intervention program was conducted in 60 workplaces across 20 urban areas in China.Workplaces were randomly divided into intervention (n=40) and control (n=20) groups.Basic information on employees at each workplace was collected by trained professionals,including sociodemographic characteristics,medical history,family history,lifestyle behaviors,medication status and physical measurements.After baseline,the intervention group received a 2-year intervention to achieve BP control,which included:(1) a workplace wellness program for all employees;(2) a guidelines-oriented hypertension management protocol.HLI including nonsmoking,nondrinking,adequate physical activity,weight within reference range and balanced diet,were coded on a 5-point scale (range:0-5,with higher score indicating a healthier lifestyle).Antihypertensive medication use was defined as taking drug within the last 2 weeks.Changes in HLI,antihypertensive medication use and BP control from baseline to 24 months were measured after the intervention.Results Overall,4655 employees were included (age:46.3±7.6 years,men:3547 (82.3%)).After 24 months of the intervention,there was a significant improvement in lifestyle[smoking (OR=0.65,95%CI:0.43-0.99;P=0.045),drinking (OR=0.52,95%CI:0.40-0.68;P<0.001),regular exercise (OR=3.10,95%CI:2.53-3.78;P<0.001),excessive intake of fatty food (OR=0.17,95%CI:0.06-0.52;P=0.002),restrictive use of salt (OR=0.26,95%CI:0.12-0.56;P=0.001)].Compare to employees with a deteriorating lifestyle after the intervention,those with an improved lifestyle had a higher BP control.In the intervention group,compared with employees not using antihypertensive medication,those who consistent used (OR=2.34;95%CI:1.16-4.72;P=0.017) or changed from not using to using antihypertensive medication (OR=2.24;95%CI:1.08-4.62;P=0.030) had higher BP control.Compared with those having lower HLI,participants with a same (OR=1.38;95%CI:0.99-1.93;P=0.056) or high (OR=1.79;95%CI:1.27~2.53;P<0.001) HLI had higher BP control.Those who used antihypertensive medication and had a high HLI had the highest BP control (OR=1.88;95%CI:1.32-2.67,P<0.001).Subgroup analysis also showed the consistent effect as the above.Conclusion These findings suggest that adherence to antihypertensive medication treatment and healthy lifestyle were associated with a significant improvement in BP control among employees with hypertension.展开更多
The current research of master cylinder pressure estimation mainly relies on hydraulic characteristic or vehicle dynamics.But they are not independently applicable to any environment and have their own scope of applic...The current research of master cylinder pressure estimation mainly relies on hydraulic characteristic or vehicle dynamics.But they are not independently applicable to any environment and have their own scope of application.In addition,about the master cylinder pressure control,there are few studies that can simultaneously balance pressure building accuracy,speed,and prevent pressure overshoot and jitter.In this paper,an adaptative fusion method based on electro-hydraulic characteristic and vehicle mode is proposed to estimate the master cylinder pressure.The fusion strategy is mainly based on the prediction performance of two algorithms under different vehicle speeds,pressures,and ABS states.Apart from this,this article also includes real-time prediction of the friction model based on RLS to improve the accuracy of the electro-hydraulic mode.In order to simultaneously balance pressure control accuracy,response speed,and prevent overshoot and jitter,this article proposes an adaptative LQR controller for MC pressure control which uses fuzzy-logic controller to adjust the weights of LQR controller based on target pressure and difference compared with actual pressure.Through mode-in-loop and hardware-in-loop tests in ramp,step and sinusoidal response,the whole estimation and control system is verified based on real hydraulic system and the performance is satisfactory under these scenes.This research proposes an adaptative pressure estimation and control architecture for integrated electro-hydraulic brake system which could eliminate pressure sensors in typical scenarios and ensure the comprehensive performance of pressure control.展开更多
Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are commo...Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are common and particularly problematic with LaCrO_(3) heaters,which can experience significant power fluctuations and even failure due to substantial resistance changes—an issue conventional thyristorcontrolled heating systems cannot effectively manage.To address this limitation,we have developed the Multi-Anvil Stable Temperature controller(MASTer),a high-performance heating system optimized for MAP experiments.MASTer enables precise,high-speed measurement of heating parameters and power output control,incorporating a gentle regulation strategy to enhance stability.It ensures consistent heating across various heater types,including LaCrO_(3),with power fluctuations limited to±0.1 W and temperature fluctuations to within±2℃ in most cases.The design,operating principles,user interface,functionality,and performance of the heating system are discussed in detail.展开更多
BACKGROUND Post-hepatectomy liver failure(PHLF),represents a serious complication after liver resection,significantly impacting the long-term outcomes for patients who undergo such surgeries.There exists a strong corr...BACKGROUND Post-hepatectomy liver failure(PHLF),represents a serious complication after liver resection,significantly impacting the long-term outcomes for patients who undergo such surgeries.There exists a strong correlation between intraoperative hemorrhage and transfusion requirements with the development of PHLF.Presently,a combination of hepatic portal occlusion techniques alongside con-trolled low central venous pressure(CLCVP)methodologies is extensively em-ployed to mitigate intraoperative bleeding.Nonetheless,limited studies have analyzed the risk factors for PHLF under CLCVP.AIM To develop and validate a nomogram that predicts the risk factors associated with the development of PHLF patients undergoing liver resection with CLCVP.METHODS We conducted a retrospective analysis of 285 patients who underwent hepatectomy for the first time and had no history of prior non-index abdominal surgeries,with hepatic inflow occlusion combined with CLCVP from January to December 2019 in Hunan Provincial People’s Hospital.Univariate and multivariate regression analyses were used to identify preoperative and intraoperative risk factors for PHLF.Eligible patients were randomly divided into training and validation groups in a 7:3 ratio,and a nomogram prediction model was constructed.RESULTS The incidence of PHLF in these patients was 22.46%.Multiple logistic analysis showed that preoperative serum albumin level,causes of liver resection(cancer or others),and cirrhosis were independent preoperative risk factors for PHLF(P<0.05)and that only post-blocking blood potassium concentration was an independent intraoperative risk factor for PHLF(P<0.05).Least absolute shrinkage and selection operator regression analysis revealed that preoperative serum albumin level,direct bilirubin level(DBIL),platelet count,causes of liver resection(cancer or others),and cirrhosis were significant predictors of PHLF.The nomogram risk prediction model based on preoperative serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),cirrhosis and post-blocking blood potassium concentration can better predict the occurrence of PHLF.CONCLUSION For patients undergoing liver resection with CLCVP,serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),and cirrhosis are independent preoperative risk factors for PHLF.展开更多
A type of single neuron adaptive PID regulator with auto-tuning gain is proposed and applied to the work control of fans, waterpumps and air-pressers etc. in Handan Iron & Steel Compel China. The robusthess of ind...A type of single neuron adaptive PID regulator with auto-tuning gain is proposed and applied to the work control of fans, waterpumps and air-pressers etc. in Handan Iron & Steel Compel China. The robusthess of induStrial parameter closed-loop process controlsystems is improved, and the work quality of the systems bettered.展开更多
This paper proposes a separated trajectory tracking controller for fishing ships at sea state level 6 to solve the trajectory tracking problem of a fishing ship in a 6-level sea state,and to adapt to different working...This paper proposes a separated trajectory tracking controller for fishing ships at sea state level 6 to solve the trajectory tracking problem of a fishing ship in a 6-level sea state,and to adapt to different working environments and safety requirements.The nonlinear feedback method is used to improve the closed-loop gain shaping algorithm.By introducing the sine function,the problem of excessive control energy of the system can be effectively solved.Moreover,an integral separation design is used to solve the influence of the integral term in conventional PID controllers on the transient performance of the system.In this paper,a common 32.98 m large fiberglass reinforced plastic(FRP)trawler is adopted for simulation research at the winds scale of Beaufort No.7.The results show that the track error is smaller than 3.5 m.The method is safe,feasible,concise and effective and has popularization value in the direction of fishing ship trajectory tracking control.This method can be used to improve the level of informatization and intelligence of fishing ships.展开更多
Rotary steering systems(RSSs)have been increasingly used to develop horizontal wells.A static push-the-bit RSS uses three hydraulic modules with varying degrees of expansion and contraction to achieve changes in the p...Rotary steering systems(RSSs)have been increasingly used to develop horizontal wells.A static push-the-bit RSS uses three hydraulic modules with varying degrees of expansion and contraction to achieve changes in the pushing force acting on the wellbore in different sizes and directions within a circular range,ultimately allowing the wellbore trajectory to be drilled in a predetermined direction.By analyzing its mathematical principles and the actual characteristics of the instrument,a vector force closed-loop control method,including steering and holding modes,was designed.The adjustment criteria for the three hydraulic modules are determined to achieve rapid adjustment of the vector force.The theoretical feasibility of the developed method was verified by comparing its results with the on-site application data of an imported rotary guidance system.展开更多
During fully mechanized caving mining of thick coal seams,a large amount of strain energy accumulates in the roof,especially when the roof is thick and hard,making it difficultfor the roof to collapse naturally.When t...During fully mechanized caving mining of thick coal seams,a large amount of strain energy accumulates in the roof,especially when the roof is thick and hard,making it difficultfor the roof to collapse naturally.When the roof eventually collapses,the accumulated energy is released instantaneously,exerting a strong impact on the roadway.To address this issue,we proposed the synergistic control method of directional comprehensive pressure relief and energy-absorbing support(PREA)for roadways with hard roofs.In this study,we developed a three-dimensional physical model test apparatus for roof cutting and pressure relief.The 122108 ventilation roadway at the Caojiatan Coal Mine,which has a thick and hard roof,was taken as the engineering example.We analyzed the evolution patterns of stress and displacement in both the stope and the roadway surrounding rocks under different schemes.The PREA reinforcement mechanism for the roadway was investigated through comparative model tests between the new and original methods.The results showed that,compared to the original method,the new method reduced surrounding rock stress by up to 60.4%,and the roadway convergence decreased by up to 52.1%.Based on these results,we proposed corresponding engineering recommendations,which can guide fieldreinforcement design and application.The results demonstrate that the PREA method effectively reduces stress and ensures the safety and stability of the roadway.展开更多
When better fuel-air mixing in the combustion chamber or a reduction in base drag are required in vehicles,rockets,and aeroplanes,the base pressure control is activated.Controlling the base pressure and drag is necess...When better fuel-air mixing in the combustion chamber or a reduction in base drag are required in vehicles,rockets,and aeroplanes,the base pressure control is activated.Controlling the base pressure and drag is necessary in both scenarios.In this work,semi-circular ribs with varying diameters(2,4,and 6 mm)positioned at six distinct positions(0.5D,1D,1.5D,2D,3D,and 4D)inside a square duct with a side of 15 mm are proposed as an efficient way to apply the passive control technique.In-depth research is done on optimising rib size for various rib sites.According to this study,the base pressure rises as rib height increases.Furthermore,the optimal location for the semi-circular ribs with a diameter of 2 mm is at 0.5D.The 1D location appears to be optimal for the 4 mm size as well.For the 6 mm size,however,the 4D position fills this function.展开更多
The aviation oxygen mask,which has a small volume of less than 1L and strong air tightness,imposes extremely high requirements on control performance of the oxygen regulator.Based on analyses of the operation principl...The aviation oxygen mask,which has a small volume of less than 1L and strong air tightness,imposes extremely high requirements on control performance of the oxygen regulator.Based on analyses of the operation principle of oxygen supply system,the dynamic model is established through the combination of mechanism analysis and experimental data.Considering that the traditional fixed-parameter controllers are difficult to meet the control requirements with changes in pulmonary ventilation,this paper presents an online feedback controller based on neural network compensation(NNC),with connection weights that can be updated without pre-training.Then mathematical simulations at different respiratory parameters,such as respiratory rate,are performed to verify the superior lower inspiratory resistance of controller with NNC.In terms of hardware,an embedded AI control platform is to complete the experimental verification.Furthermore,the work may have downward compatibility to achieve stable oxygen supply in civil fields,such as medical ventilators,high-altitude expeditions.展开更多
The current study focuses on the motion-pressure coupled control for a multicapsule stratospheric airship and transforms the path-tracking and heading-hold control of airships into guidance tracking with a time-varyin...The current study focuses on the motion-pressure coupled control for a multicapsule stratospheric airship and transforms the path-tracking and heading-hold control of airships into guidance tracking with a time-varying weighted sum of longitudinal and lateral velocities by the definition of compound speed.Herein,an improved nonlinear predictive control method is provided to reduce the control energy consumption by the rolling optimization of controller parameters based on finite time intervals,ensuring infinite-time path-tracking tasks.Simultaneously,combined with the proposed cyclic regulation process of safe pressure between internal and external capsules,this study can fully reflect the force-thermal coupled rule of airships under the actions of atmospheric environment and maneuvering force,while evaluating the long-endurance capability of airships under the conditions of safe superheating and overpressure.The effectiveness of the motionpressure coupled controller was verified through numerical simulations,which can overcome the influence of environmental wind and achieve a tracking effect for the desired cruise path and compound speed.The airspeed provided during the cyclic circadian time caused the maximum superheating of the helium controlled within 30C.The helium in the internal and external capsules achieved circadian regulation.The equivalent micropore diameter of the capsule of 5 mm can achieve 55 days of long-endurance flight.The controller satisfies the requirements of cruise-flight application modes for multicapsule stratospheric airships with important engineering value.展开更多
Introduction: High blood pressure is defined as blood pressure greater than or equal to 140 mm Hg for systolic and or 90 mm Hg for diastolic. It constitutes a major public health problem, the leading chronic disease i...Introduction: High blood pressure is defined as blood pressure greater than or equal to 140 mm Hg for systolic and or 90 mm Hg for diastolic. It constitutes a major public health problem, the leading chronic disease in the world. The objective was to determine the prevalence, treatment rate and control of hypertension. Methods: This was a cross-sectional and descriptive study which took place over a period of 6 months in a hospital environment and in the general population. Results: Of the 1000 participants, 637 had hypertension, giving a prevalence of 63.70% with a female predominance. Thirty-three percent (33%) were unaware of their high blood pressure. The age group 60 and more was the most represented (44%). A proportion of 33 and 23.20 were overweight and obese participants, respectively. Male subjects were more overweight than female, unlike obesity which was more common among female subjects. Sixty-two percent (62%) of hypertensives were treated, of whom 44% were non-compliant. The excessively high cost and consumption of medications as needed were the main factors in therapeutic non-compliance. Twenty-two percent (22%) of all hypertensive patients and 35% of treated hypertensive patients were controlled. Women were more treated but less observant and less controlled than men. Therapeutic coverage and combination therapy rates were lower in rural areas. Hypertensives who had a high level of education were better treated and controlled than those who had no level. Conclusion: High blood pressure remains a real public health problem in Mali. It is more common in people aged 60 and over and in females. One in three hypertensives were unaware of their hypertension. The majority received antihypertensive treatments, but only a minority of them had their hypertension controlled.展开更多
Objective: The association hypertension and diabetes is important. The two pathologies may influence each other. The aim was to study the correlation between glycemic control and blood pressure control and to determin...Objective: The association hypertension and diabetes is important. The two pathologies may influence each other. The aim was to study the correlation between glycemic control and blood pressure control and to determine the factors associated with blood pressure control. Methodology: This was a descriptive cross-sectional study with an analytical focus over 7 months. Patients were recruited as outpatients and all underwent ambulatory blood pressure measure, glycated hemoglobin and creatinine measurements, and assessment of compliance with treatment. Results: During this period 116 patients were collected. The predominance was female 69%. The mean age of the patients was 62 ± 7 years with a peak between 60 and 70 years. The average age of hypertension was 12 years and that of diabetes 6 1/2 years. The most frequently associated cardiovascular risk factor was a sedentary lifestyle (71.5%) after age. 57.8% of patients were not controlled at the office, with a predominance of systolic hypertension (58.2%). 61.6% of patients were controlled by ambulatory blood pressure measure, a rate of 47.8% of white coat hypertension. Glycemic control was observed in 42.2% of cases and 87% of patients had good renal function (glomerular filter rate ≥ 60 ml/mn). Therapeutic compliance was good in 53.4% of cases and dual therapy was the most used therapeutic modality 44.8% (52 patients) followed by triple therapy. The factors associated with poor blood pressure control were glycemic imbalance, non-compliance and monotherapy. Dual therapy had a protective effect. Conclusion: The association of hypertension and type 2 diabetes is frequent. The risk of occurrence increases with age. Ambulatory blood pressure measure is the best method to assess blood pressure control. Optimization of blood pressure control should also include optimization of glycemic control.展开更多
Nuclear power plants exhibit non-linear and time-variable dynamics.Therefore,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor...Nuclear power plants exhibit non-linear and time-variable dynamics.Therefore,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWR)is a fourth-generation conceptual reactor.In an SCWR,the non-linear dynamics of the reactor require a controller capable of control-ling the nonlinearities.In this study,a pressure-tube-type SCWR was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled simultaneously.In an SCWR,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power maneuvering.Reactor point kinetics equations with three groups of delayed neutrons were used in the simulation.Higher-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous studies.The controlled parameters were reactor power,steam temperature,and pressure.Notably,for these parameters,the PI controller had certain instabilities in the presence of disturbances.The classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering phenomenon.HOSMC was highly accurate and stable and had a small computational cost.In reality,it followed the desired values without oscillations and chattering.展开更多
Based on the principle of transient perturbation analysis,in this paper,a method to objectively determine the weather pattern formed by sea fog is provided.On the basis of the classification results,the circulation si...Based on the principle of transient perturbation analysis,in this paper,a method to objectively determine the weather pattern formed by sea fog is provided.On the basis of the classification results,the circulation situation,divergence and vertical velocity field,and the vertical profile of temperature and humidity are synthesized and analyzed.The basic characteristics of the circulation and physical field of sea fog under low pressure control(L type sea fog)are obtained,and the results are compared with the sea fog under the control of high pressure(H type sea fog):a)L type sea fogs potential height anomaly disturbance is mainly manifested in the low layer,and its average value is-65.66 gpm,gradually weakening upward;b)L type sea fogs inversion structure is weaker than H type sea fogs when it occurs,the fog layer is thicker and the high relative humidity level is high over the fog layer,while the H type sea fogs fog layer has a relatively obvious dry layer;c)L sea fog has three layers of structure at the vertical direction.The first layer 1000-950 hPa is convergence accompanied by weak rise and subsidence,the second layer 950-850 hPa is divergence accompanied by weak subsidence,and the third layer 850 to 500hPa is gradually strengthened.While there are two layer structures of the H type sea fog.1000 hPa is divergence accompanied by weak rising and sinking movement,950-500 hPa is a uniform subsidence movement.d)Probability density statistical analysis further quantified the vertical movement of L and H type sea fog and the distribution of relative humidity in each layer.These conclusions provide an important reference for forecasting the sea fog in the northwest of the Yellow Sea under the condition of low pressure circulation in summer.展开更多
Objective:We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release.Impact Statement:This design is inspired by the skin baroreceptors,which are mechanosensitive elements of...Objective:We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release.Impact Statement:This design is inspired by the skin baroreceptors,which are mechanosensitive elements of the peripheral nervous system.We adopt the finger touching to trigger the electric stimulation,ensuring a fast-response and user-friendly administration with potentially minimal off-target effects.Introduction:Chronic skin diseases bring about large,recurrent skin damage and often require convenient and timely transdermal treatment.Traditional methods lack spatiotemporal controllable dosage,leaving a risk of skin irritation or drug resistance issues.Methods:The patch consists of drug-containing microneedles and stretchable electrode array.The electrode array,integrated with the piezoconductive switch and flexible battery,provides a mild electric current only at the spot that is pressed.Drugs in microneedles will then flow along the current into the skin tissues.The stretchable feature also provides the mechanical robustness and electric stability of the device on large skin area.Results:This device delivers Cy3 dye in pig skin with spatiotemporally controlled dosage,showing~8 times higher fluorescence intensity than the passive delivery.We also deliver insulin and observe the reduction of the blood glucose level in the mouse model upon pressing.Compared with passive delivery without pressing,the dosage of drugs released by the simulation is 2.83 times higher.Conclusion:This baroreceptor-inspired microneedle skin patch acts as a good example of the biomimicking microneedle device in the precise control of the drug release profile at the spatiotemporal resolution.展开更多
This paper describes a supervisory hierarchical fuzzy controller （SHFC） for regulating pressure in a real-time pilot pressure control system. The input scaling factor tuning of a direct expert controller is made usi...This paper describes a supervisory hierarchical fuzzy controller （SHFC） for regulating pressure in a real-time pilot pressure control system. The input scaling factor tuning of a direct expert controller is made using the error and process input parameters in a closed loop system in order to obtain better controller performance for set-point change and load disturbances. This on-line tuning method reduces operator involvement and enhances the controller performance to a wide operating range. The hierarchical control scheme consists of an intelligent upper level supervisory fuzzy controller and a lower level direct fuzzy controller. The upper level controller provides a mechanism to the main goal of the system and the lower level controller delivers the solutions to a particular situation. The control algorithm for the proposed scheme has been developed and tested using an ARM7 microcontroller-based embedded target board for a nonlinear pressure process having dead time. To demonstrate the effectiveness, the results of the proposed hierarchical controller, fuzzy controller and conventional proportional-integral （PI） controller are analyzed. The results prove that the SHFC performance is better in terms of stability and robustness than the conventional control methods.展开更多
BACKGROUND： Although cupping remains a popular treatment modality worldwide, its efficacy for most diseases, including hypertension, has not been scientifically evaluated. OBJECTIVE： We aimed to determine the effica...BACKGROUND： Although cupping remains a popular treatment modality worldwide, its efficacy for most diseases, including hypertension, has not been scientifically evaluated. OBJECTIVE： We aimed to determine the efficacy of wet-cupping for high blood pressure, and the incidence of the procedure＇s side effects in the intervention group. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： This is a randomized controlled trial conducted in the General Practice Department at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between May 2013 and February 2014. There were two groups （40 participants each）： intervention group undergoing wet-cupping （hijama） in addition to conventional hypertension treatment, and a control group undergoing only conventional hypertension treatment. Three wet-cupping sessions were performed every other day. MAIN OUTCOME MEASURE： The mean systolic and diastolic blood pressures were measured using a validated automatic sphygmomanometer. The follow-up period was 8 weeks. RESULTS： Wet-cupping provided an immediate reduction of systolic blood pressure. After 4 weeks of follow-up, the mean systolic blood pressure in the intervention group was 8.4 mmHg less than in the control group （P = 0.046）. After 8 weeks, there were no significant differences in blood pressures between the intervention and control groups. In this study, wet-cupping did not result in any serious side effects. CONCLUSION： Wet-cupping therapy is effective for reducing systolic blood pressure in hypertensive patients for up to 4 weeks, without serious side effects. Wet-cupping should be considered as a complementary hypertension treatment, and further studies are needed.展开更多
Efficiency and emissions of spark-ignited engines are significantly affected by combustion phase which can usually be indicated by crank angle of 50% mass burnt （CA50）. Managing combustion phase at the optimal value...Efficiency and emissions of spark-ignited engines are significantly affected by combustion phase which can usually be indicated by crank angle of 50% mass burnt （CA50）. Managing combustion phase at the optimal value at which the maximal efficiency can be achieved is a challenging issue due to the cyclic variations of combustion process. This paper addresses this issue in two loops： CA50 set-point optimization （outer loop） and set-point tracking （inner loop） by controlling spark advance （SA）. Extremum seeking approach maximizing thermal efficiency is employed in the CA50 set-point optimization. A proportional- integral （PI） controller is adopted to make the moving average value of CA50 tracking the optimal CA50 set-point determined in the outer loop. Moreover, in order to obtain fast responses at steady and transient operations, feed-forward maps are designed for extremum seeking controller and PI controller, respectively. Finally, experimental validations are conducted on a six-cylinder gasoline at steady and transient operations to show the effectiveness of proposed control scheme.展开更多
The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonline...The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. In order to meet the demand of generating dynamic pressure signal in the application of the hardware-in-the-loop simulation of aerospace engineering, a positive and negative pneumatic pressure servo system is provided to implement dynamic adjustment of sealed chamber pressure. A mathematical model is established with simulation and experiment being implemented afterwards to discuss the characteristics of the system, which shows serious asymmetry in the process of charging and discharging. Based on the analysis of the system dynamics, a fuzzy proportional integral derivative （PID） controller with asymmetric fuzzy compensator is proposed. Different from conventional adjusting mecha- nisms employing the error and change in error of the controlled variable as input parameters, the current cham- ber pressure and charging or discharging state are chosen as inputs of the compensator, which improves adaptability. To verify the effectiveness and performance of the pro- posed controller, the comparison experiments tracking sinusoidal and square wave commands are conducted. Experimental results show that the proposed controller can obtain better dynamic performance and relatively consis- tent control performance across the scope of work （2-140 kPa）. The research proposes a fuzzy control method to overcome asymmetry and enhance adaptability for the positive and negative pneumatic pressure servo system.展开更多
基金supported by grant 2011BAI11B01 from the Projects in the Chinese National Science and Technology Pillar Program during the 12th Five-year Plan Periodby grant 2017-I2M-1-004 from the Chinese Academy of Medical Science Innovation Fund for Medical Sciencesby the Major science and technology special plan project of Yunnan Province (202302AA310045)。
文摘Background Both medication and non-medication therapies are effective approaches to control blood pressure (BP) in hypertension patients.However,the association of joint changes in antihypertensive medication use and healthy lifestyle index (HLI)with BP control among hypertension patients is seldom reported,which needs to provide more evidence by prospective intervention studies.We examined the association of antihypertensive medication use and HLI with BP control among employees with hypertension in China based on a workplace-based multicomponent intervention program.Methods Between January 2013 and December 2014,a cluster randomized clinical trial of a workplace-based multicomponent intervention program was conducted in 60 workplaces across 20 urban areas in China.Workplaces were randomly divided into intervention (n=40) and control (n=20) groups.Basic information on employees at each workplace was collected by trained professionals,including sociodemographic characteristics,medical history,family history,lifestyle behaviors,medication status and physical measurements.After baseline,the intervention group received a 2-year intervention to achieve BP control,which included:(1) a workplace wellness program for all employees;(2) a guidelines-oriented hypertension management protocol.HLI including nonsmoking,nondrinking,adequate physical activity,weight within reference range and balanced diet,were coded on a 5-point scale (range:0-5,with higher score indicating a healthier lifestyle).Antihypertensive medication use was defined as taking drug within the last 2 weeks.Changes in HLI,antihypertensive medication use and BP control from baseline to 24 months were measured after the intervention.Results Overall,4655 employees were included (age:46.3±7.6 years,men:3547 (82.3%)).After 24 months of the intervention,there was a significant improvement in lifestyle[smoking (OR=0.65,95%CI:0.43-0.99;P=0.045),drinking (OR=0.52,95%CI:0.40-0.68;P<0.001),regular exercise (OR=3.10,95%CI:2.53-3.78;P<0.001),excessive intake of fatty food (OR=0.17,95%CI:0.06-0.52;P=0.002),restrictive use of salt (OR=0.26,95%CI:0.12-0.56;P=0.001)].Compare to employees with a deteriorating lifestyle after the intervention,those with an improved lifestyle had a higher BP control.In the intervention group,compared with employees not using antihypertensive medication,those who consistent used (OR=2.34;95%CI:1.16-4.72;P=0.017) or changed from not using to using antihypertensive medication (OR=2.24;95%CI:1.08-4.62;P=0.030) had higher BP control.Compared with those having lower HLI,participants with a same (OR=1.38;95%CI:0.99-1.93;P=0.056) or high (OR=1.79;95%CI:1.27~2.53;P<0.001) HLI had higher BP control.Those who used antihypertensive medication and had a high HLI had the highest BP control (OR=1.88;95%CI:1.32-2.67,P<0.001).Subgroup analysis also showed the consistent effect as the above.Conclusion These findings suggest that adherence to antihypertensive medication treatment and healthy lifestyle were associated with a significant improvement in BP control among employees with hypertension.
基金Supported by National Natural Science Foundation of China(Grant Nos.52202494,52202495)Chongqing Special Project for Technological Innovation and Application Development(Grant No.CSTB2022TIAD-DEX0014).
文摘The current research of master cylinder pressure estimation mainly relies on hydraulic characteristic or vehicle dynamics.But they are not independently applicable to any environment and have their own scope of application.In addition,about the master cylinder pressure control,there are few studies that can simultaneously balance pressure building accuracy,speed,and prevent pressure overshoot and jitter.In this paper,an adaptative fusion method based on electro-hydraulic characteristic and vehicle mode is proposed to estimate the master cylinder pressure.The fusion strategy is mainly based on the prediction performance of two algorithms under different vehicle speeds,pressures,and ABS states.Apart from this,this article also includes real-time prediction of the friction model based on RLS to improve the accuracy of the electro-hydraulic mode.In order to simultaneously balance pressure control accuracy,response speed,and prevent overshoot and jitter,this article proposes an adaptative LQR controller for MC pressure control which uses fuzzy-logic controller to adjust the weights of LQR controller based on target pressure and difference compared with actual pressure.Through mode-in-loop and hardware-in-loop tests in ramp,step and sinusoidal response,the whole estimation and control system is verified based on real hydraulic system and the performance is satisfactory under these scenes.This research proposes an adaptative pressure estimation and control architecture for integrated electro-hydraulic brake system which could eliminate pressure sensors in typical scenarios and ensure the comprehensive performance of pressure control.
基金supported by the National Science Fund for Distinguished Young Scholars(Grant No.T2225027)the National Key R&D Program of China(Grant No.2023YFA1608902).
文摘Maintaining stable high temperatures under pressure remains a challenge in high-pressure,high-temperature experiments using multi-anvil presses(MAPs).Temperature fluctuations exceeding 10℃ at high pressures are common and particularly problematic with LaCrO_(3) heaters,which can experience significant power fluctuations and even failure due to substantial resistance changes—an issue conventional thyristorcontrolled heating systems cannot effectively manage.To address this limitation,we have developed the Multi-Anvil Stable Temperature controller(MASTer),a high-performance heating system optimized for MAP experiments.MASTer enables precise,high-speed measurement of heating parameters and power output control,incorporating a gentle regulation strategy to enhance stability.It ensures consistent heating across various heater types,including LaCrO_(3),with power fluctuations limited to±0.1 W and temperature fluctuations to within±2℃ in most cases.The design,operating principles,user interface,functionality,and performance of the heating system are discussed in detail.
基金Supported by the Natural Science Foundation of Hunan Province,No.2018JJ3291the Scientific Research Project of the Hunan Provincial Health Commission,No.202104111288.
文摘BACKGROUND Post-hepatectomy liver failure(PHLF),represents a serious complication after liver resection,significantly impacting the long-term outcomes for patients who undergo such surgeries.There exists a strong correlation between intraoperative hemorrhage and transfusion requirements with the development of PHLF.Presently,a combination of hepatic portal occlusion techniques alongside con-trolled low central venous pressure(CLCVP)methodologies is extensively em-ployed to mitigate intraoperative bleeding.Nonetheless,limited studies have analyzed the risk factors for PHLF under CLCVP.AIM To develop and validate a nomogram that predicts the risk factors associated with the development of PHLF patients undergoing liver resection with CLCVP.METHODS We conducted a retrospective analysis of 285 patients who underwent hepatectomy for the first time and had no history of prior non-index abdominal surgeries,with hepatic inflow occlusion combined with CLCVP from January to December 2019 in Hunan Provincial People’s Hospital.Univariate and multivariate regression analyses were used to identify preoperative and intraoperative risk factors for PHLF.Eligible patients were randomly divided into training and validation groups in a 7:3 ratio,and a nomogram prediction model was constructed.RESULTS The incidence of PHLF in these patients was 22.46%.Multiple logistic analysis showed that preoperative serum albumin level,causes of liver resection(cancer or others),and cirrhosis were independent preoperative risk factors for PHLF(P<0.05)and that only post-blocking blood potassium concentration was an independent intraoperative risk factor for PHLF(P<0.05).Least absolute shrinkage and selection operator regression analysis revealed that preoperative serum albumin level,direct bilirubin level(DBIL),platelet count,causes of liver resection(cancer or others),and cirrhosis were significant predictors of PHLF.The nomogram risk prediction model based on preoperative serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),cirrhosis and post-blocking blood potassium concentration can better predict the occurrence of PHLF.CONCLUSION For patients undergoing liver resection with CLCVP,serum albumin level,DBIL,platelet count,causes of liver resection(cancer or others),and cirrhosis are independent preoperative risk factors for PHLF.
文摘A type of single neuron adaptive PID regulator with auto-tuning gain is proposed and applied to the work control of fans, waterpumps and air-pressers etc. in Handan Iron & Steel Compel China. The robusthess of induStrial parameter closed-loop process controlsystems is improved, and the work quality of the systems bettered.
基金supported by Liaoning Provincial Department of Education 2023 Basic Research Projects for Universities and Colleges(Grant No.JYTQN2023131)Liaoning Provincial Science and Technology Program:Cooperative Control and Recognition of Unmanned Vessels for Fishing Vessel Operation Scenarios(Grant No.600024003)Liaoning Provincial Department of Education Scientific Research Funding Project(Grant No.LJKZ0726).
文摘This paper proposes a separated trajectory tracking controller for fishing ships at sea state level 6 to solve the trajectory tracking problem of a fishing ship in a 6-level sea state,and to adapt to different working environments and safety requirements.The nonlinear feedback method is used to improve the closed-loop gain shaping algorithm.By introducing the sine function,the problem of excessive control energy of the system can be effectively solved.Moreover,an integral separation design is used to solve the influence of the integral term in conventional PID controllers on the transient performance of the system.In this paper,a common 32.98 m large fiberglass reinforced plastic(FRP)trawler is adopted for simulation research at the winds scale of Beaufort No.7.The results show that the track error is smaller than 3.5 m.The method is safe,feasible,concise and effective and has popularization value in the direction of fishing ship trajectory tracking control.This method can be used to improve the level of informatization and intelligence of fishing ships.
基金supported by the Opening Foundation of China National Logging Corporation(CNLC20229C06)the China Petroleum Technical Service Corporation's science project'Development and application of 475 rotary steering system'(2024T-001001)。
文摘Rotary steering systems(RSSs)have been increasingly used to develop horizontal wells.A static push-the-bit RSS uses three hydraulic modules with varying degrees of expansion and contraction to achieve changes in the pushing force acting on the wellbore in different sizes and directions within a circular range,ultimately allowing the wellbore trajectory to be drilled in a predetermined direction.By analyzing its mathematical principles and the actual characteristics of the instrument,a vector force closed-loop control method,including steering and holding modes,was designed.The adjustment criteria for the three hydraulic modules are determined to achieve rapid adjustment of the vector force.The theoretical feasibility of the developed method was verified by comparing its results with the on-site application data of an imported rotary guidance system.
基金supported by the National Natural Science Foundation of China(Grant Nos.U24A2088 and 42277174)the Fundamental Research Funds for the Central Universities,China(Grant No.2024JCCXSB01).
文摘During fully mechanized caving mining of thick coal seams,a large amount of strain energy accumulates in the roof,especially when the roof is thick and hard,making it difficultfor the roof to collapse naturally.When the roof eventually collapses,the accumulated energy is released instantaneously,exerting a strong impact on the roadway.To address this issue,we proposed the synergistic control method of directional comprehensive pressure relief and energy-absorbing support(PREA)for roadways with hard roofs.In this study,we developed a three-dimensional physical model test apparatus for roof cutting and pressure relief.The 122108 ventilation roadway at the Caojiatan Coal Mine,which has a thick and hard roof,was taken as the engineering example.We analyzed the evolution patterns of stress and displacement in both the stope and the roadway surrounding rocks under different schemes.The PREA reinforcement mechanism for the roadway was investigated through comparative model tests between the new and original methods.The results showed that,compared to the original method,the new method reduced surrounding rock stress by up to 60.4%,and the roadway convergence decreased by up to 52.1%.Based on these results,we proposed corresponding engineering recommendations,which can guide fieldreinforcement design and application.The results demonstrate that the PREA method effectively reduces stress and ensures the safety and stability of the roadway.
基金supported by the Structures and Materials(S&M)Research Lab of Prince Sultan Universitysupport of Prince Sultan University in paying the article processing charges(APC)for this publication.
文摘When better fuel-air mixing in the combustion chamber or a reduction in base drag are required in vehicles,rockets,and aeroplanes,the base pressure control is activated.Controlling the base pressure and drag is necessary in both scenarios.In this work,semi-circular ribs with varying diameters(2,4,and 6 mm)positioned at six distinct positions(0.5D,1D,1.5D,2D,3D,and 4D)inside a square duct with a side of 15 mm are proposed as an efficient way to apply the passive control technique.In-depth research is done on optimising rib size for various rib sites.According to this study,the base pressure rises as rib height increases.Furthermore,the optimal location for the semi-circular ribs with a diameter of 2 mm is at 0.5D.The 1D location appears to be optimal for the 4 mm size as well.For the 6 mm size,however,the 4D position fills this function.
基金supported by the National Natural Science Foundation of China(Nos.61973172,62003177,62003175 and 61973175).
文摘The aviation oxygen mask,which has a small volume of less than 1L and strong air tightness,imposes extremely high requirements on control performance of the oxygen regulator.Based on analyses of the operation principle of oxygen supply system,the dynamic model is established through the combination of mechanism analysis and experimental data.Considering that the traditional fixed-parameter controllers are difficult to meet the control requirements with changes in pulmonary ventilation,this paper presents an online feedback controller based on neural network compensation(NNC),with connection weights that can be updated without pre-training.Then mathematical simulations at different respiratory parameters,such as respiratory rate,are performed to verify the superior lower inspiratory resistance of controller with NNC.In terms of hardware,an embedded AI control platform is to complete the experimental verification.Furthermore,the work may have downward compatibility to achieve stable oxygen supply in civil fields,such as medical ventilators,high-altitude expeditions.
基金supported by the National Natural Science Foundation of China(Nos.62073019,62227810).
文摘The current study focuses on the motion-pressure coupled control for a multicapsule stratospheric airship and transforms the path-tracking and heading-hold control of airships into guidance tracking with a time-varying weighted sum of longitudinal and lateral velocities by the definition of compound speed.Herein,an improved nonlinear predictive control method is provided to reduce the control energy consumption by the rolling optimization of controller parameters based on finite time intervals,ensuring infinite-time path-tracking tasks.Simultaneously,combined with the proposed cyclic regulation process of safe pressure between internal and external capsules,this study can fully reflect the force-thermal coupled rule of airships under the actions of atmospheric environment and maneuvering force,while evaluating the long-endurance capability of airships under the conditions of safe superheating and overpressure.The effectiveness of the motionpressure coupled controller was verified through numerical simulations,which can overcome the influence of environmental wind and achieve a tracking effect for the desired cruise path and compound speed.The airspeed provided during the cyclic circadian time caused the maximum superheating of the helium controlled within 30C.The helium in the internal and external capsules achieved circadian regulation.The equivalent micropore diameter of the capsule of 5 mm can achieve 55 days of long-endurance flight.The controller satisfies the requirements of cruise-flight application modes for multicapsule stratospheric airships with important engineering value.
文摘Introduction: High blood pressure is defined as blood pressure greater than or equal to 140 mm Hg for systolic and or 90 mm Hg for diastolic. It constitutes a major public health problem, the leading chronic disease in the world. The objective was to determine the prevalence, treatment rate and control of hypertension. Methods: This was a cross-sectional and descriptive study which took place over a period of 6 months in a hospital environment and in the general population. Results: Of the 1000 participants, 637 had hypertension, giving a prevalence of 63.70% with a female predominance. Thirty-three percent (33%) were unaware of their high blood pressure. The age group 60 and more was the most represented (44%). A proportion of 33 and 23.20 were overweight and obese participants, respectively. Male subjects were more overweight than female, unlike obesity which was more common among female subjects. Sixty-two percent (62%) of hypertensives were treated, of whom 44% were non-compliant. The excessively high cost and consumption of medications as needed were the main factors in therapeutic non-compliance. Twenty-two percent (22%) of all hypertensive patients and 35% of treated hypertensive patients were controlled. Women were more treated but less observant and less controlled than men. Therapeutic coverage and combination therapy rates were lower in rural areas. Hypertensives who had a high level of education were better treated and controlled than those who had no level. Conclusion: High blood pressure remains a real public health problem in Mali. It is more common in people aged 60 and over and in females. One in three hypertensives were unaware of their hypertension. The majority received antihypertensive treatments, but only a minority of them had their hypertension controlled.
文摘Objective: The association hypertension and diabetes is important. The two pathologies may influence each other. The aim was to study the correlation between glycemic control and blood pressure control and to determine the factors associated with blood pressure control. Methodology: This was a descriptive cross-sectional study with an analytical focus over 7 months. Patients were recruited as outpatients and all underwent ambulatory blood pressure measure, glycated hemoglobin and creatinine measurements, and assessment of compliance with treatment. Results: During this period 116 patients were collected. The predominance was female 69%. The mean age of the patients was 62 ± 7 years with a peak between 60 and 70 years. The average age of hypertension was 12 years and that of diabetes 6 1/2 years. The most frequently associated cardiovascular risk factor was a sedentary lifestyle (71.5%) after age. 57.8% of patients were not controlled at the office, with a predominance of systolic hypertension (58.2%). 61.6% of patients were controlled by ambulatory blood pressure measure, a rate of 47.8% of white coat hypertension. Glycemic control was observed in 42.2% of cases and 87% of patients had good renal function (glomerular filter rate ≥ 60 ml/mn). Therapeutic compliance was good in 53.4% of cases and dual therapy was the most used therapeutic modality 44.8% (52 patients) followed by triple therapy. The factors associated with poor blood pressure control were glycemic imbalance, non-compliance and monotherapy. Dual therapy had a protective effect. Conclusion: The association of hypertension and type 2 diabetes is frequent. The risk of occurrence increases with age. Ambulatory blood pressure measure is the best method to assess blood pressure control. Optimization of blood pressure control should also include optimization of glycemic control.
文摘Nuclear power plants exhibit non-linear and time-variable dynamics.Therefore,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWR)is a fourth-generation conceptual reactor.In an SCWR,the non-linear dynamics of the reactor require a controller capable of control-ling the nonlinearities.In this study,a pressure-tube-type SCWR was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled simultaneously.In an SCWR,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power maneuvering.Reactor point kinetics equations with three groups of delayed neutrons were used in the simulation.Higher-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous studies.The controlled parameters were reactor power,steam temperature,and pressure.Notably,for these parameters,the PI controller had certain instabilities in the presence of disturbances.The classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering phenomenon.HOSMC was highly accurate and stable and had a small computational cost.In reality,it followed the desired values without oscillations and chattering.
基金supported by National Natural Science Foundation of China(No.41576108 and No.41605006)Natural Science Foundation project of Shandong Province(No.ZR2016DB26).
文摘Based on the principle of transient perturbation analysis,in this paper,a method to objectively determine the weather pattern formed by sea fog is provided.On the basis of the classification results,the circulation situation,divergence and vertical velocity field,and the vertical profile of temperature and humidity are synthesized and analyzed.The basic characteristics of the circulation and physical field of sea fog under low pressure control(L type sea fog)are obtained,and the results are compared with the sea fog under the control of high pressure(H type sea fog):a)L type sea fogs potential height anomaly disturbance is mainly manifested in the low layer,and its average value is-65.66 gpm,gradually weakening upward;b)L type sea fogs inversion structure is weaker than H type sea fogs when it occurs,the fog layer is thicker and the high relative humidity level is high over the fog layer,while the H type sea fogs fog layer has a relatively obvious dry layer;c)L sea fog has three layers of structure at the vertical direction.The first layer 1000-950 hPa is convergence accompanied by weak rise and subsidence,the second layer 950-850 hPa is divergence accompanied by weak subsidence,and the third layer 850 to 500hPa is gradually strengthened.While there are two layer structures of the H type sea fog.1000 hPa is divergence accompanied by weak rising and sinking movement,950-500 hPa is a uniform subsidence movement.d)Probability density statistical analysis further quantified the vertical movement of L and H type sea fog and the distribution of relative humidity in each layer.These conclusions provide an important reference for forecasting the sea fog in the northwest of the Yellow Sea under the condition of low pressure circulation in summer.
基金support by General Research Fund(GRF)grant from the Research Grants Council(RGC)of the Hong Kong Special Administrative Region China(CityU11200820,CityU11100323)the Mainland/Hong Kong Joint Research Scheme sponsored by the RGC Hong Kong and the National Natural Science Foundation of China(N_CityU118/20).
文摘Objective:We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release.Impact Statement:This design is inspired by the skin baroreceptors,which are mechanosensitive elements of the peripheral nervous system.We adopt the finger touching to trigger the electric stimulation,ensuring a fast-response and user-friendly administration with potentially minimal off-target effects.Introduction:Chronic skin diseases bring about large,recurrent skin damage and often require convenient and timely transdermal treatment.Traditional methods lack spatiotemporal controllable dosage,leaving a risk of skin irritation or drug resistance issues.Methods:The patch consists of drug-containing microneedles and stretchable electrode array.The electrode array,integrated with the piezoconductive switch and flexible battery,provides a mild electric current only at the spot that is pressed.Drugs in microneedles will then flow along the current into the skin tissues.The stretchable feature also provides the mechanical robustness and electric stability of the device on large skin area.Results:This device delivers Cy3 dye in pig skin with spatiotemporally controlled dosage,showing~8 times higher fluorescence intensity than the passive delivery.We also deliver insulin and observe the reduction of the blood glucose level in the mouse model upon pressing.Compared with passive delivery without pressing,the dosage of drugs released by the simulation is 2.83 times higher.Conclusion:This baroreceptor-inspired microneedle skin patch acts as a good example of the biomimicking microneedle device in the precise control of the drug release profile at the spatiotemporal resolution.
文摘This paper describes a supervisory hierarchical fuzzy controller （SHFC） for regulating pressure in a real-time pilot pressure control system. The input scaling factor tuning of a direct expert controller is made using the error and process input parameters in a closed loop system in order to obtain better controller performance for set-point change and load disturbances. This on-line tuning method reduces operator involvement and enhances the controller performance to a wide operating range. The hierarchical control scheme consists of an intelligent upper level supervisory fuzzy controller and a lower level direct fuzzy controller. The upper level controller provides a mechanism to the main goal of the system and the lower level controller delivers the solutions to a particular situation. The control algorithm for the proposed scheme has been developed and tested using an ARM7 microcontroller-based embedded target board for a nonlinear pressure process having dead time. To demonstrate the effectiveness, the results of the proposed hierarchical controller, fuzzy controller and conventional proportional-integral （PI） controller are analyzed. The results prove that the SHFC performance is better in terms of stability and robustness than the conventional control methods.
基金funded by King Abdulaziz University(Jeddah,Saudi Arabia)Kashef Diagnostics Factory(Jeddah,Saudi Arabia)
文摘BACKGROUND： Although cupping remains a popular treatment modality worldwide, its efficacy for most diseases, including hypertension, has not been scientifically evaluated. OBJECTIVE： We aimed to determine the efficacy of wet-cupping for high blood pressure, and the incidence of the procedure＇s side effects in the intervention group. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： This is a randomized controlled trial conducted in the General Practice Department at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between May 2013 and February 2014. There were two groups （40 participants each）： intervention group undergoing wet-cupping （hijama） in addition to conventional hypertension treatment, and a control group undergoing only conventional hypertension treatment. Three wet-cupping sessions were performed every other day. MAIN OUTCOME MEASURE： The mean systolic and diastolic blood pressures were measured using a validated automatic sphygmomanometer. The follow-up period was 8 weeks. RESULTS： Wet-cupping provided an immediate reduction of systolic blood pressure. After 4 weeks of follow-up, the mean systolic blood pressure in the intervention group was 8.4 mmHg less than in the control group （P = 0.046）. After 8 weeks, there were no significant differences in blood pressures between the intervention and control groups. In this study, wet-cupping did not result in any serious side effects. CONCLUSION： Wet-cupping therapy is effective for reducing systolic blood pressure in hypertensive patients for up to 4 weeks, without serious side effects. Wet-cupping should be considered as a complementary hypertension treatment, and further studies are needed.
文摘Efficiency and emissions of spark-ignited engines are significantly affected by combustion phase which can usually be indicated by crank angle of 50% mass burnt （CA50）. Managing combustion phase at the optimal value at which the maximal efficiency can be achieved is a challenging issue due to the cyclic variations of combustion process. This paper addresses this issue in two loops： CA50 set-point optimization （outer loop） and set-point tracking （inner loop） by controlling spark advance （SA）. Extremum seeking approach maximizing thermal efficiency is employed in the CA50 set-point optimization. A proportional- integral （PI） controller is adopted to make the moving average value of CA50 tracking the optimal CA50 set-point determined in the outer loop. Moreover, in order to obtain fast responses at steady and transient operations, feed-forward maps are designed for extremum seeking controller and PI controller, respectively. Finally, experimental validations are conducted on a six-cylinder gasoline at steady and transient operations to show the effectiveness of proposed control scheme.
基金Supported by National Natural Science Foundation of China(Grant No.51575199)
文摘The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. In order to meet the demand of generating dynamic pressure signal in the application of the hardware-in-the-loop simulation of aerospace engineering, a positive and negative pneumatic pressure servo system is provided to implement dynamic adjustment of sealed chamber pressure. A mathematical model is established with simulation and experiment being implemented afterwards to discuss the characteristics of the system, which shows serious asymmetry in the process of charging and discharging. Based on the analysis of the system dynamics, a fuzzy proportional integral derivative （PID） controller with asymmetric fuzzy compensator is proposed. Different from conventional adjusting mecha- nisms employing the error and change in error of the controlled variable as input parameters, the current cham- ber pressure and charging or discharging state are chosen as inputs of the compensator, which improves adaptability. To verify the effectiveness and performance of the pro- posed controller, the comparison experiments tracking sinusoidal and square wave commands are conducted. Experimental results show that the proposed controller can obtain better dynamic performance and relatively consis- tent control performance across the scope of work （2-140 kPa）. The research proposes a fuzzy control method to overcome asymmetry and enhance adaptability for the positive and negative pneumatic pressure servo system.
