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Normothermic regional perfusion mobile teams in controlled donation after circulatory death pathway: Evidence and peculiarities
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作者 Chiara Lazzeri Manuela Bonizzoli +1 位作者 Giuseppe Feltrin Adriano Peris 《World Journal of Transplantation》 2024年第4期78-83,共6页
To facilitate the implementation of controlled donation after circulatory death(cDCD)programs even in hospitals not equipped with a local Extracorporeal Membrane Oxygenation(ECMO)team(Spokes),some countries and Italia... To facilitate the implementation of controlled donation after circulatory death(cDCD)programs even in hospitals not equipped with a local Extracorporeal Membrane Oxygenation(ECMO)team(Spokes),some countries and Italian Regions have launched a local cDCD network with a ECMO mobile team who move from Hub hospitals to Spokes for normothermic regional perfusion(NRP)implantation in the setting of a cDCD pathway.While ECMO teams have been clearly defined by the Extracorporeal Life Support Organization,regarding composition,responsibilities and training programs,no clear,widely accepted indications are to date available for NRP teams.Although existing NRP mobile networks were developed due to the urgent need to increase the number of cDCDs,there is now the necessity for transplantation medicine to identify the peculiarities and responsibility of a NRP team for all those centers launching a cDCD pathway.Thus,in the present manuscript we summarized the character-istics of an ECMO mobile team,highlighting similarities and differences with the NRP mobile team.We also assessed existing evidence on NRP teams with the goal of identifying the characteristic and essential features of an NRP mobile team for a cDCD program,especially for those centers who are starting the program.Differences were identified between the mobile ECMO team and NRP mobile team.The common essential feature for both mobile teams is high skills and experience to reduce complications and,in the case of cDCD,to reduce the total warm ischemic time.Dedicated training programs should be developed for the launch of de novo NRP teams. 展开更多
关键词 controlled donation after circulatory death Extracorporeal membrane oxygenation Normothermic regional perfusion Mobile teams Warm ischemia time
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Experimental Study on Vibration Control of Offshore Wind Turbines Using a Ball Vibration Absorber 被引量:6
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作者 Jie Li Zili Zhang Jianbing Chen 《Energy and Power Engineering》 2012年第3期153-157,共5页
To minimize the excessive vibration and prolong the fatigue life of the offshore wind turbine systems, it is of value to control the vibration that is induced within the structure by implementing certain kinds of damp... To minimize the excessive vibration and prolong the fatigue life of the offshore wind turbine systems, it is of value to control the vibration that is induced within the structure by implementing certain kinds of dampers. In this paper, a ball vibration absorber (BVA) is experimentally investigated through a series of shake table tests on a 1/13 scaled wind turbine model. The reductions in top displacement, top acceleration, bottom stress and platform stress of the wind turbine tower system subjected to earthquakes and equivalent wind-wave loads, respectively, with a ball absorber are examined. Cases of the tower with rotating blades are also investigated to validate the efficacy of this damper in mitigating the vibration of an operating wind turbine. The experimental results indicate that the dynamic performance of the tested wind turbine model with a ball absorber is significantly improved compared with that of the uncontrolled structure in terms of the peak response reduction. 展开更多
关键词 ofFSHORE Wind Turbine SHAKE TABLE Test VIBRATION control ball VIBRATION ABSORBER
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Tuning the reactivity of Al-Ni by fine coating of halogen-containing energetic composites 被引量:3
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作者 Su-lan Yang Ke-juan Meng +2 位作者 Wu-xi Xie Hong-qi Nie Qi-Long Yan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第10期1810-1821,共12页
In this paper,various core-shell structured Al—Ni@ECs composites have been prepared by a spray-drying technique.The involved ECs refer to the energetic composites(ECs)of ammonium perchlorate/nitrocellulose(AP/NC,NA)a... In this paper,various core-shell structured Al—Ni@ECs composites have been prepared by a spray-drying technique.The involved ECs refer to the energetic composites(ECs)of ammonium perchlorate/nitrocellulose(AP/NC,NA)and polyvinylidene fluoride/hexanitrohexaazaisowurtzitane(PVDF/CL-20,PC).Two Al—Ni mixtures were prepared at atomic ratios of 1:1 and 1:3 and named as Al/Ni and Al/3Ni,respectively.The thermal reactivity and combustion behaviors of Al—Ni@ECs composites have been comprehensively investigated.Results showed that the reactivity and combustion performance of Al—Ni could be enhanced by introducing both NA and PC energetic composites.Among which the Al/Ni@NA composite exhibited higher reactivity and improved combustion performance.The measured flame propagation rate(v=20.6 mm/s),average combustion wave temperature(T_(max)=1567.0°C)and maximum temperature rise rate(γ_(t)=1633.6°C/s)of Al/Ni@NA are higher than that of the Al/Ni(v=15.8 mm/s,T_(max)=858.0°C,andγ_(t)=143.5°C/s).The enhancement in combustion properties could be due to presence of the acidic gaseous products from ECs,which could etch the Al_(2)O_(3)shell on the surface of Al particles,and make the inner active Al to be easier transported,so that an intimate and faster intermetallic reaction between Al and Ni would be realized.Furthermore,the morphologies and chemical compositions of the condensed combustion products(CCPs)of Al—Ni@ECs composites were found to be different depending on the types of ECs.The compositions of CCPs are dominated with the Al—Ni intermetallics,combining with a trace amount of Al_(5)O_(6)N and Al_(2)O_(3). 展开更多
关键词 Arrested high energy ball milling intermetallic alloy Combustion performance Energetic composites Reactivity control
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Stabilization of switched systems with all unstable modes:application to the aircraft team problem
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作者 TAVAKOLIFAR Dariush KHALOOZADEH Hamid AMJADIFARD Roya 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第4期792-798,共7页
The method of stabilizing switched systems based on the optimal control is applied,with all modes unstable,for a typical example of the multi-agent system.First,the optimal control method for stabilizing switched syst... The method of stabilizing switched systems based on the optimal control is applied,with all modes unstable,for a typical example of the multi-agent system.First,the optimal control method for stabilizing switched systems is introduced.For this purpose,a switching table rule procedure is constructed.This procedure is inspired by the optimal control that identifies the optimal trajectory for the switched systems.In the next step,the stability of a multi-agent system is studied,considering different unstable connection topologies.Finally,the optimal control method is successfully applied to an aircraft team,as an example of the multi-agent systems.Simulation results evaluate and confirm the successful application of this method in the aircraft team example. 展开更多
关键词 switched SYSTEM multi-agent SYSTEM STABILIZATION optimal control UNSTABLE MODES AIRCRAFT team
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Tri-directional shaking table tests of vibration sensitive equipment with static dynamics interchangeable-ball pendulum system 被引量:2
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作者 C.S. Tsai Yung-Chang Lin +1 位作者 Wen-Shin Chen H.C. Su 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第1期103-112,共10页
Recently, the high-tech industry has become a key industry for economic development in many countries. However, vibration sensitive equipment located in these industrial buildings is vulnerable during earthquakes, whi... Recently, the high-tech industry has become a key industry for economic development in many countries. However, vibration sensitive equipment located in these industrial buildings is vulnerable during earthquakes, which may cause huge economic loss. In this study, an innovative isolator for safeguarding the vibration sensitive equipment, namely, the static dynamics interchangeable^all pendulum system (SDI-BPS) is proposed and investigated to examine its protective capability for the vibration sensitive equipment during earthquakes through a series of tri-directional shaking table tests. The experimental results illustrate that the SDI-BPS isolator can provide significant damping to rolling types of base isolation systems for reducing the bearing displacement and size, and avoid the stress concentration, which can cause damage or scratches on the rolling surface of the isolator, to prolong its life span of service. The SDI-BPS isolator also provides excellent capability in protecting the vibration sensitive equipment and exhibits a stable behavior under long terms of service loadings and earthquakes. 展开更多
关键词 ball pendulum system critical equipment base isolation vibration sensitive equipment base isolator passive control earthquake engineering structural control
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Optimal Decoupling Control Method and Its Application to a Ball Mill Coal-pulverizing System 被引量:3
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作者 Yue Fu Chengwen Hong Jingyi Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第6期1035-1043,共9页
Abstract-The conventional optimal tracking control method cannot realize decoupling control of linear systems with a strong coupling property. To solve this problem, in this paper, an optimal decoupling control method... Abstract-The conventional optimal tracking control method cannot realize decoupling control of linear systems with a strong coupling property. To solve this problem, in this paper, an optimal decoupling control method is proposed, which can simultaneousiy provide optimal performance. The optimal decoupling controller is composed of an inner-loop decoupling controller and an outer-loop optimal tracking controller. First, by introducing one virtual control variable, the original differential equation on state is converted to a generalized system on output. Then, by introducing the other virtual control variable, and viewing the coupling terms as the measurable disturbances, the generalized system is open-loop decoupled. Finally, for the decoupled system, the optimal tracking control method is used. It is proved that the decoupling control is optimal for a certain performance index. Simulations on a ball mill coal-pulverizing system are conducted. The results show the effectiveness and superiority of the proposed method as compared with the conventional optimal quadratic tracking (LQT) control method. 展开更多
关键词 ball mill coal-pulverizing system linear system optimal decoupling control optimal quadratic tracking (LQT)control.
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Integral sliding mode control for flexible ball screw drives with matched and mismatched uncertainties and disturbances 被引量:2
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作者 包达飞 汤文成 董亮 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第9期1992-2000,共9页
The design of servo controllers for flexible ball screw drives with matched and mismatched disturbances and uncertainties is focused to improve the tracking performance and bandwidth of ball screw drives.A two degrees... The design of servo controllers for flexible ball screw drives with matched and mismatched disturbances and uncertainties is focused to improve the tracking performance and bandwidth of ball screw drives.A two degrees of freedom mass model is established based on the axial vibration characteristics of the transport ball screw,and the controller of an adaptive integral sliding mode is proposed combining the optimal design of state feedback gain matrix K to restrain the vibration and the matched disturbances and uncertainties.Then for the counteraction of the mismatched disturbances and uncertainties,a nonlinear disturbance observer is also developed.The trajectory tracking performance experiments and bandwidth analysis were conducted on experimental setup with the proposed control method.It is proved that the adaptive integral sliding mode controller has a high tracking performance and bandwidth especially for the axial vibration characteristics model of ball screw drives.And the ball screw tracking accuracy also has a considerable improvement with the application of the proposed nonlinear disturbance observer. 展开更多
关键词 ball screw drives matched and mismatched disturbances and uncertainties axial vibration characteristics adaptive integral sliding mode control nonlinear disturbance observer
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Intelligent Dynamic Inversion Controller Design for Ball and Beam System
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作者 Ibrahim M.Mehedi Abdulah Jeza Aljohani +4 位作者 Md Mottahir Alam Mohamed Mahmoud Mohammed J.Abdulaal Muhammad Bilal Waleed Alasmary 《Computers, Materials & Continua》 SCIE EI 2022年第8期2341-2355,共15页
The Ball and beam system(BBS)is an attractive laboratory experimental tool because of its inherent nonlinear and open-loop unstable properties.Designing an effective ball and beam system controller is a real challenge... The Ball and beam system(BBS)is an attractive laboratory experimental tool because of its inherent nonlinear and open-loop unstable properties.Designing an effective ball and beam system controller is a real challenge for researchers and engineers.In this paper,the control design technique is investigated by using Intelligent Dynamic Inversion(IDI)method for this nonlinear and unstable system.The proposed control law is an enhanced version of conventional Dynamic Inversion control incorporating an intelligent control element in it.The Moore-PenroseGeneralized Inverse(MPGI)is used to invert the prescribed constraint dynamics to realize the baseline control law.A sliding mode-based intelligent control element is further augmented with the baseline control to enhance the robustness against uncertainties,nonlinearities,and external disturbances.The semi-global asymptotic stability of IDI control is guaranteed in the sense of Lyapunov.Numerical simulations and laboratory experiments are carried out on this ball and beam physical system to analyze the effectiveness of the controller.In addition to that,comparative analysis of RGDI control with classical Linear Quadratic Regulator and Fractional Order Controller are also presented on the experimental test bench. 展开更多
关键词 ball and beam system(BBS) unstable system internal model PD controllers IDI control robust control
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Hamiltonian Servo: Control and Estimation of a Large Team of Autonomous Robotic Vehicles
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作者 Vladimir Ivancevic Peyam Pourbeik 《Intelligent Control and Automation》 2017年第4期175-197,共23页
This paper proposes a novel Hamiltonian servo system, a combined modeling framework for control and estimation of a large team/fleet of autonomous robotic vehicles. The Hamiltonian servo framework represents high-dime... This paper proposes a novel Hamiltonian servo system, a combined modeling framework for control and estimation of a large team/fleet of autonomous robotic vehicles. The Hamiltonian servo framework represents high-dimensional, nonlinear and non-Gaussian generalization of the classical Kalman servo system. After defining the Kalman servo as a motivation, we define the affine Hamiltonian neural network for adaptive nonlinear control of a team of UGVs in continuous time. We then define a high-dimensional Bayesian particle filter for estimation of a team of UGVs in discrete time. Finally, we formulate a hybrid Hamiltonian servo system by combining the continuous-time control and the discrete-time estimation into a coherent framework that works like a predictor-corrector system. 展开更多
关键词 team of UGVs KALMAN SERVO HAMILTONIAN control Bayesian ESTIMATION
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Automatic Team Assignment and Jersey Number Recognition in Football Videos
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作者 Ragd Alhejaily Rahaf Alhejaily +2 位作者 Mai Almdahrsh Shareefah Alessa Saleh Albelwi 《Intelligent Automation & Soft Computing》 SCIE 2023年第6期2669-2684,共16页
Football is one of the most-watched sports,but analyzing players’per-formance is currently difficult and labor intensive.Performance analysis is done manually,which means that someone must watch video recordings and ... Football is one of the most-watched sports,but analyzing players’per-formance is currently difficult and labor intensive.Performance analysis is done manually,which means that someone must watch video recordings and then log each player’s performance.This includes the number of passes and shots taken by each player,the location of the action,and whether or not the play had a successful outcome.Due to the time-consuming nature of manual analyses,interest in automatic analysis tools is high despite the many interdependent phases involved,such as pitch segmentation,player and ball detection,assigning players to their teams,identifying individual players,activity recognition,etc.This paper proposes a system for developing an automatic video analysis tool for sports.The proposed system is the first to integrate multiple phases,such as segmenting the field,detecting the players and the ball,assigning players to their teams,and iden-tifying players’jersey numbers.In team assignment,this research employed unsu-pervised learning based on convolutional autoencoders(CAEs)to learn discriminative latent representations and minimize the latent embedding distance between the players on the same team while simultaneously maximizing the dis-tance between those on opposing teams.This paper also created a highly accurate approach for the real-time detection of the ball.Furthermore,it also addressed the lack of jersey number datasets by creating a new dataset with more than 6,500 images for numbers ranging from 0 to 99.Since achieving a high perfor-mance in deep learning requires a large training set,and the collected dataset was not enough,this research utilized transfer learning(TL)to first pretrain the jersey number detection model on another large dataset and then fine-tune it on the target dataset to increase the accuracy.To test the proposed system,this paper presents a comprehensive evaluation of its individual stages as well as of the sys-tem as a whole. 展开更多
关键词 Football video analysis player detection ball detection team assignment jersey number recognition
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Design and Simulation of an Audio Signal Alerting and Automatic Control System
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作者 Winfred Adjardjah John Awuah Addor +1 位作者 Wisdom Opare Isaac Mensah Ayipeh 《Communications and Network》 2023年第4期98-119,共22页
A large part of our daily lives is spent with audio information. Massive obstacles are frequently presented by the colossal amounts of acoustic information and the incredibly quick processing times. This results in th... A large part of our daily lives is spent with audio information. Massive obstacles are frequently presented by the colossal amounts of acoustic information and the incredibly quick processing times. This results in the need for applications and methodologies that are capable of automatically analyzing these contents. These technologies can be applied in automatic contentanalysis and emergency response systems. Breaks in manual communication usually occur in emergencies leading to accidents and equipment damage. The audio signal does a good job by sending a signal underground, which warrants action from an emergency management team at the surface. This paper, therefore, seeks to design and simulate an audio signal alerting and automatic control system using Unity Pro XL to substitute manual communication of emergencies and manual control of equipment. Sound data were trained using the neural network technique of machine learning. The metrics used are Fast Fourier transform magnitude, zero crossing rate, root mean square, and percentage error. Sounds were detected with an error of approximately 17%;thus, the system can detect sounds with an accuracy of 83%. With more data training, the system can detect sounds with minimal or no error. The paper, therefore, has critical policy implications about communication, safety, and health for underground mine. 展开更多
关键词 Emergency Response Emergency Management team Audio Signal Alerting Automatic control System Uni Pro XL Manual Communication Fast Fourier Transform Magnitude Zero Crossing Rate Root Means Square
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WELL-POSEDNESS AND CONTROLLABILITY AND OBSERVABILITY OF A COUPLED VIBRATING SYSTEM
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作者 徐艳琴 胡顺菊 《Acta Mathematica Scientia》 SCIE CSCD 1994年第S1期64-72,共9页
In this paper, we derive a new description form of coupled bending and torsionalvibrating system with boundary control and observation through Green's formula and provethat it is equivalent to the original form. O... In this paper, we derive a new description form of coupled bending and torsionalvibrating system with boundary control and observation through Green's formula and provethat it is equivalent to the original form. On the basis of this. we prove the control system iswell-posed in time and frequency domain and completely controllable and observable. 展开更多
关键词 Coupled bending and torsional vibrating system Boundary control and obsevation ball-posedness
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Visual Feedback Balance Control of a Robot Manipulator and Ball-Beam System
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作者 Ching-Long Shih Jung-Hsien Hsu Chi-Jen Chang 《Journal of Computer and Communications》 2017年第9期8-18,共11页
In this paper, we present a vision guided robotic ball-beam balancing control system, consisting of a robot manipulator (actuator), a ball-beam system (plant) and a machine vision system (feedback). The machine vision... In this paper, we present a vision guided robotic ball-beam balancing control system, consisting of a robot manipulator (actuator), a ball-beam system (plant) and a machine vision system (feedback). The machine vision system feedbacks real-time beam angle and ball position data at a speed of 50 frames per second. Based on feedback data, the end-effector of a robot manipulator is driven to control the ball position by maneuvering of the inclination angle of the ball-beam system. The overall control system is implemented with two FPGA chips, one for machine vision processing, and one for robot joints servo PID controllers as well as ball position PD controller. Experiments are performed on a 5-axes robot manipulator to validate the proposed ball beam balancing control system. 展开更多
关键词 ball-Beam System Robot MANIPULATOR VISION FEEDBACK control PID/PD control FPGA
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Mathematical modelling of ball and plate system with experimental and correlation function-based model validation
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作者 T.R.Dil Kumar S.J.Mija 《Control Theory and Technology》 EI CSCD 2024年第2期326-341,共16页
The ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the sys... The ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. The system comprises a ball and plate mechanism and a rotary servo unit. The ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. The nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. The simplified nonlinear model of the system is obtained with suitable assumptions. The model is linearized around the operating point using the Jacobian. The validity of the developed models is investigated through correlation function analysis. The open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MATLAB/Simulink platform. Since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PSO (particle swarm optimization) PID control scheme. 展开更多
关键词 ball and plate system Correlation function Model validation Particle swarm optimization(PSO) PSO PID controller
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A study on controlled cooling process for making bainitic ductile iron 被引量:4
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作者 Y.H.Jiang R.Zhou D.H.Lu 《China Foundry》 SCIE CAS 2004年第S1期29-31,共3页
In the present research, TTT curve of bainitic ductile iron under the condition of controlled cooling was generated. The cooling rate of grinding ball and its temperature distribution were also measured at the same ti... In the present research, TTT curve of bainitic ductile iron under the condition of controlled cooling was generated. The cooling rate of grinding ball and its temperature distribution were also measured at the same time. It can be concluded that the bainitic zone of TTT curve is separated from the pearlitic zone. As compared to the water-quenching condition, more even cooling rate and temperature distribution can be achieved in the controlled cooling process. The controlled cooling can keep away from pearlitic zone in the high temperature cooling stage and produce similar results to the process of traditional isothermal cooling with a low cooling rate in the low temperature cooling stage. 展开更多
关键词 controlled cooling grinding ball ductile iron bainitic ductile iron austenite-ferrite ductile iron BAinITE
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Cooperative Search and Task Allocation Among Heterogeneous Teams of UAVs 被引量:2
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作者 沈延航 周洲 《Defence Technology(防务技术)》 SCIE EI CAS 2008年第3期198-202,共5页
A cooperative control method of multi-class UAV(unmanned air vehicle) team is investigated.During the mission,the UAVs perform search,classification,attack and battle damage assessment(BDA) tasks at various locations,... A cooperative control method of multi-class UAV(unmanned air vehicle) team is investigated.During the mission,the UAVs perform search,classification,attack and battle damage assessment(BDA) tasks at various locations,which involves a combination of the team intelligence type of decision making combined with control,estimate and real-time trajectory optimization.The search-theoretic approach based on rate of return(ROR) maps is developed to get the cooperative search strategy.Templates are developed and views are combined to maximize the probability of correct target identification over various aspect angles.Monte Carle simulation runs for the scenario to evaluate the performance of the approach with various decision parameters,UAVs distributions and UAV team characteristics.Simulation results show that the cooperative behavior can significantly improve the operational effectiveness of UAV team,and the cooperative control allows for near optimal solution of the correlative behavior of a group of UAVs in battlefield. 展开更多
关键词 飞机构造 飞机设计 控制导航技术 无人飞行器
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基于TeamSTEPPS风险防控模式的护理在气管切开患者感染防控中的应用
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作者 裴中霞 李伟 +5 位作者 刘莉莉 李志萍 江云兰 朱育琼 刘丹 李小月 《中国中西医结合耳鼻咽喉科杂志》 2024年第1期73-76,共4页
目的 探讨基于强化临床表现和医疗安全的团队策略与工具(Team STEPPS)?风险防控模式的护理在气管切开患者感染防控中的应用。方法 选取2021年1月~2022年12月在安庆市第一人民医院入住的82例气管切开患者。其中2021年41例为对照组,实施... 目的 探讨基于强化临床表现和医疗安全的团队策略与工具(Team STEPPS)?风险防控模式的护理在气管切开患者感染防控中的应用。方法 选取2021年1月~2022年12月在安庆市第一人民医院入住的82例气管切开患者。其中2021年41例为对照组,实施常规的气管切开术后护理;2022年41例为观察组,在常规的气管切开术后护理基础上,基于Team STEPPS风险防控模式的护理措施。比较两组患者感染高风险事件发生率、医护合作情况、患者满意度。结果 观察组患者感染高风险事件发生率低于对照组,医护合作得分、患者满意度明显高于对照组(P<0.05)。结论 基于Team STEPPS风险防控模式的护理在气管切开患者感染防控中应用,降低了感染风险发生的事件、医护合作程度明显增强,患者的满意度提高显著,值得在临床推广应用。 展开更多
关键词 团队策略与工具 气管切开 感染防控 风险评估
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Microwave absorption performance of FeCoNiAlCr_(0.9)alloy powders by adjusting the amount of process control agent 被引量:6
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作者 Yuping Duan Huifang Pang +2 位作者 Xin Wen Xuefeng Zhang Tongmin Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第18期209-216,共8页
Different amounts of absolute ethanol(0-50 mL)are used as process control agents(PCA)to prepare FeCoNiAlCr0.9 high entropy alloy(HEA)powders via 90 h ball milling.The results show that the increased amount of PCA play... Different amounts of absolute ethanol(0-50 mL)are used as process control agents(PCA)to prepare FeCoNiAlCr0.9 high entropy alloy(HEA)powders via 90 h ball milling.The results show that the increased amount of PCA plays an active role in the crystallinity of powders,and regulate the thickness and size distribution of flake particles.As the volume of PCA increases,the real and imaginary parts(ε′andε″)of complex permittivity get increased by the enhancement of the interface polarization and surface polarization,while the increase in the real and imaginary parts(μ′andμ″)of complex permeability arises from the increased anisotropic energy.The addition of PCA not only promotes the reflection loss but also extends the effective bandwidth(up to 4.28 GHz).Here,the performance adjustment of HEA electromagnetic absorber is realized by forthrightly changing the process parameters of ball milling. 展开更多
关键词 FeCoNiAlCr_(0.9) ball milling Electromagnetic performance Process control agent
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The mechanism for fuzzy-ball working fluids for controlling & killing lost circulation 被引量:12
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作者 ZHENG LiHui KONG LingChen CAO Yuan WANG HuiYun HE XiaoQing 《Chinese Science Bulletin》 SCIE EI CAS 2010年第35期4074-4082,共9页
Lost circulation controlling & killing material has been a focused issue since a long time ago.A novel leak resistance fluid with the raw materials such as SDS,SDBS,HES,PAM and proprietary productions has been dev... Lost circulation controlling & killing material has been a focused issue since a long time ago.A novel leak resistance fluid with the raw materials such as SDS,SDBS,HES,PAM and proprietary productions has been developed from laboratory.The experiment and application shows that the new leak resistance fluid can plug leaking passage of different sizes simultaneously.Observing with 1000 to 2000 time microscope,it is found that the working liquid contains a kind of spherical material which has the microstructure of "one core,two layers,and three membranes".When it is in a static state,the inside of the material looks like an airbag and the outside looks like some fuzzy things which has high gel strength.While when it is in a dynamic state,the fuzzy thing is cut or scattered and flow ability becomes much better.That is the reason why it is called fuzzy-ball.When the diameter or the width of the leak passage is greater than the fuzzy-ball's,the fuzzy-ball accumulates in conical shape to decompose the working fluid pressure of liquid column to achieve blocking;when the diameter or the width of the leak passage is equivalent to the fuzzy-ball's,the fuzzy-ball changes from sphere to oval-shape to increase the resistance to the leak passage and plug the holes;when the diameter or the width of the leak passage is smaller than the fuzzy-ball's,the leaks could be blocked up by the non-permeable membrane formed by the gel of high strength in the working fluid.In these cases,the leak passages of different sizes could be blocked comprehensively. 展开更多
关键词 模糊 工作流体 十二烷基苯磺酸钠 泄漏通道 十二烷基硫酸钠 通道宽度 机制 制球
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球磨机控制系统INA方法设计 被引量:12
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作者 田沛 马平 +1 位作者 吕丽霞 罗培军 《华北电力学院学报》 北大核心 1994年第1期69-72,共4页
采用INA方法设计了球磨机多变量控制系统,并对所设计的系统进行了仿真检验。结果表明,该系统具有良好的调节品质,对模型参数变化不敏感.本文采用KMM单回路调节器对该系统加以实现,从而为球磨机控制提供了一种新的和实用的方案.
关键词 球磨机 IAN方法 控制系统
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