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Research on the Application of Evidence-Based Quality Control Circle to Improve the Implementation Rate of Airway Management Measures in Adult Critically Ill Patients
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作者 Yujiao Yan Jing Wu +4 位作者 Juan Liu Yanting Yuan Lixin Liu Huaxin Ye Juan Ding 《Yangtze Medicine》 2024年第1期8-19,共12页
Objective: To explore the effect of evidence-based quality control circle (QCC) in improving the implementation rate of airway management measures in adult critically ill patients. Methods: Based on the Joanna Briggs ... Objective: To explore the effect of evidence-based quality control circle (QCC) in improving the implementation rate of airway management measures in adult critically ill patients. Methods: Based on the Joanna Briggs Institute (JBI) evidence-based health care model, the best evidence of airway management in adult critically ill patients was obtained and applied to the clinic. Results: The total implementation rate of airway management measures in adult critically ill patients increased from 23.62% before the implementation of quality control circle to 88.82%, and the pulmonary infection rate in critically ill patients decreased from 42.31% to 21.74%, with statistical significance between the two groups (P 0.05). Conclusion: Evidence-based quality control circle activities can standardize the practice standards of airway management in critically ill patients, reduce the occurrence of patients’ airway related complications, and improve clinical outcomes. 展开更多
关键词 Critically Ill Patients Airway Management Be Evidence-based Quality control Circle Intensive Care Unit (ICU)
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Performance-based semi-active control algorithm for protecting base isolated buildings from near-fault earthquakes 被引量:3
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作者 Behnam Mehrparvar Taramarz Khoshnoudian 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2012年第1期43-55,共13页
Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions. Various control strategies, including passive, active and se... Base isolated structures have been found to be at risk in near-fault regions as a result of long period pulses that may exist in near-source ground motions. Various control strategies, including passive, active and semi-active control systems, have been investigated to overcome this problem. This study focuses on the development of a semi-active control algorithm based on several performance levels anticipated from an isolated building during different levels of ground shaking corresponding to various earthquake hazard levels. The proposed performance-based algorithm is based on a modified version of the well-known semi-active skyhook control algorithm. The proposed control algorithm changes the control gain depending on the level of shaking imposed on the structure. The proposed control system has been evaluated using a series of analyses performed on a base isolated benchmark building subjected to seven pairs of scaled ground motion records. Simulation results show that the newly proposed algorithm is effective in improving the structural and nonstructural performance of the building for selected earthquakes. 展开更多
关键词 structural control active control semi-active control base isolation
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Role based access control design using Triadic concept analysis 被引量:9
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作者 Ch.Aswani Kumar S.Chandra Mouliswaran +1 位作者 LI Jin-hai C.Chandrasekar 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第12期3183-3191,共9页
Role based access control is one of the widely used access control models.There are investigations in the literature that use knowledge representation mechanisms such as formal concept analysis(FCA),description logics... Role based access control is one of the widely used access control models.There are investigations in the literature that use knowledge representation mechanisms such as formal concept analysis(FCA),description logics,and Ontology for representing access control mechanism.However,while using FCA,investigations reported in the literature so far work on the logic that transforms the three dimensional access control matrix into dyadic formal contexts.This transformation is mainly to derive the formal concepts,lattice structure and implications to represent role hierarchy and constraints of RBAC.In this work,we propose a methodology that models RBAC using triadic FCA without transforming the triadic access control matrix into dyadic formal contexts.Our discussion is on two lines of inquiry.We present how triadic FCA can provide a suitable representation of RBAC policy and we demonstrate how this representation follows role hierarchy and constraints of RBAC on sample healthcare network available in the literature. 展开更多
关键词 access control concept lattice role based access control role hierarchy triadic context triadic concept analysis
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A Trajectory Prediction Based Intelligent Handover Control Method in UAV Cellular Networks 被引量:3
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作者 Bo Hu Hanzhang Yang +1 位作者 Lei Wang Shanzhi Chen 《China Communications》 SCIE CSCD 2019年第1期1-14,共14页
The airborne base station(ABS) can provide wireless coverage to the ground in unmanned aerial vehicle(UAV) cellular networks.When mobile users move among adjacent ABSs,the measurement information reported by a single ... The airborne base station(ABS) can provide wireless coverage to the ground in unmanned aerial vehicle(UAV) cellular networks.When mobile users move among adjacent ABSs,the measurement information reported by a single mobile user is used to trigger the handover mechanism.This handover mechanism lacks the consideration of movement state of mobile users and the location relationship between mobile users,which may lead to handover misjudgments and even communication interrupts.In this paper,we propose an intelligent handover control method in UAV cellular networks.Firstly,we introduce a deep learning model to predict the user trajectories.This prediction model learns the movement behavior of mobile users from the measurement information and analyzes the positional relations between mobile users such as avoiding collision and accommodating fellow pedestrians.Secondly,we propose a handover decision method,which can calculate the users' corresponding receiving power based on the predicted location and the characteristic of air-to-ground channel,to make handover decisions accurately.Finally,we use realistic data sets with thousands of non-linear trajectories to verify the basic functions and performance of our proposed intelligent handover controlmethod.The simulation results show that the handover success rate of the proposed method is 8% higher than existing methods. 展开更多
关键词 UAV AIRBORNE base STATION HANDOVER control TRAJECTORY prediction DEEP learning
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Genetic algorithm based LQR vibration wireless control of laminated plate using photostrictive actuators 被引量:5
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作者 Chen Dejin Zheng Shijie Wang Hongtao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2012年第1期83-90,共8页
A photostrictive type of opto-electromechanical actuator activated by high-energy lights can introduce actuation and control effects without hard-wired connections. This paper addresses the controllability aspect in w... A photostrictive type of opto-electromechanical actuator activated by high-energy lights can introduce actuation and control effects without hard-wired connections. This paper addresses the controllability aspect in wireless vibration control of plate structures via photostrictive actuators. A modal force index, which has taken into account the mode number, the spatial distribution, and the dimension of the actuator, is chosen as an objective function to determine the optimal locations of photostrictive actuators. A linear methodology is proposed in this paper and the vibration equation is written in the standard state-space form. A binary-coded GA based combined optimal placement and LQR (linear quadratic regulator) control scheme has been incorporated, which maximizes the modal force index, the closed loop damping and minimizes input light intensity to the actuators. In the present method only three weighting factors have been used to search optimal Q and R matrices using GA, which reduces chromosome length and hence minimizes computational time. Numerical results demonstrate that the use of strategically positioned actuator patches can effectively control the fundamental modes that dominate the structural vibration. 展开更多
关键词 photostrictive actuators GA based LQR scheme wireless vibration control
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Disturbance Observer Based Control for Four Wheel Steering Vehicles With Model Reference 被引量:11
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作者 Shuyou Yu Jing Wang +1 位作者 Yan Wang Hong Chen 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第6期1121-1127,共7页
This paper presents a disturbance observer based control strategy for four wheel steering systems in order to improve vehicle handling stability. By combination of feedforward control and feedback control, the front a... This paper presents a disturbance observer based control strategy for four wheel steering systems in order to improve vehicle handling stability. By combination of feedforward control and feedback control, the front and rear wheel steering angles are controlled simultaneously to follow both the desired sideslip angle and the yaw rate of the reference vehicle model.A nonlinear three degree-of-freedom four wheel steering vehicle model containing lateral, yaw and roll motions is built up, which also takes the dynamic effects of crosswind into consideration.The disturbance observer based control method is provided to cope with ignored nonlinear dynamics and to handle exogenous disturbances. Finally, a simulation experiment is carried out,which shows that the proposed four wheel steering vehicle can guarantee handling stability and present strong robustness against external disturbances. 展开更多
关键词 Disturbance observer based control four wheel steering handling stability model reference.
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Design and Implementation of File Access and Control System Based on Dynamic Web 被引量:3
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作者 GAO Fuxiang YAO Lan BAO Shengfei YU Ge 《Wuhan University Journal of Natural Sciences》 CAS 2006年第5期1233-1237,共5页
A dynamic Web application, which can help the departments of enterprise to collaborate with each other conveniently, is proposed. Several popular design solutions are introduced at first. Then, dynamic Web system is c... A dynamic Web application, which can help the departments of enterprise to collaborate with each other conveniently, is proposed. Several popular design solutions are introduced at first. Then, dynamic Web system is chosen for developing the file access and control system. Finally, the paper gives the detailed process of the design and implementation of the system, which includes some key problems such as solutions of document management and system security. Additionally, the limitations of the system as well as the suggestions of further improvement are also explained. 展开更多
关键词 file access and control ACTIVEX role based access control (RBAC) VERSION
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A Lyapunov-based three-axis attitude intelligent control approach for unmanned aerial vehicle 被引量:2
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作者 A.H.Mazinan 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4669-4678,共10页
A novel Lyapunov-based three-axis attitude intelligent control approach via allocation scheme is considered in the proposed research to deal with kinematics and dynamics regarding the unmanned aerial vehicle systems.T... A novel Lyapunov-based three-axis attitude intelligent control approach via allocation scheme is considered in the proposed research to deal with kinematics and dynamics regarding the unmanned aerial vehicle systems.There is a consensus among experts of this field that the new outcomes in the present complicated systems modeling and control are highly appreciated with respect to state-of-the-art.The control scheme presented here is organized in line with a new integration of the linear-nonlinear control approaches,as long as the angular velocities in the three axes of the system are accurately dealt with in the inner closed loop control.And the corresponding rotation angles are dealt with in the outer closed loop control.It should be noted that the linear control in the present outer loop is first designed through proportional based linear quadratic regulator(PD based LQR) approach under optimum coefficients,while the nonlinear control in the corresponding inner loop is then realized through Lyapunov-based approach in the presence of uncertainties and disturbances.In order to complete the inner closed loop control,there is a pulse-width pulse-frequency(PWPF) modulator to be able to handle on-off thrusters.Furthermore,the number of these on-off thrusters may be increased with respect to the investigated control efforts to provide the overall accurate performance of the system,where the control allocation scheme is realized in the proposed strategy.It may be shown that the dynamics and kinematics of the unmanned aerial vehicle systems have to be investigated through the quaternion matrix and its corresponding vector to avoid presenting singularity of the results.At the end,the investigated outcomes are presented in comparison with a number of potential benchmarks to verify the approach performance. 展开更多
关键词 Lyapunov based control approach PD based LQR approach control allocation scheme kinematics and dynamics unmanned aerial vehicle system on-off thrusters PWPF modulator
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Operator-Based Robust Nonlinear Control for SISO and MIMO Nonlinear Systems With PI Hysteresis 被引量:3
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作者 Shuhui Bi Lei Wang +1 位作者 Shengjun Wen Mingcong Deng 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第2期523-530,共8页
In this paper, operator based robust nonlinear control for single-input single-output(SISO) and multi-input multi-output(MIMO) nonlinear uncertain systems preceded by generalized Prandtl-Ishlinskii(PI) hysteresis is c... In this paper, operator based robust nonlinear control for single-input single-output(SISO) and multi-input multi-output(MIMO) nonlinear uncertain systems preceded by generalized Prandtl-Ishlinskii(PI) hysteresis is considered respectively. In detail, by using operator based robust right coprime factorization approach, the control system design structures including feedforward and feedback controllers for both SISO and MIMO nonlinear uncertain systems are given, respectively.In which, the controller design includes the information of PI hysteresis and its inverse, and some sufficient conditions for the controllers in both SISO and MIMO systems should be satisfied are also derived respectively. Based on the proposed conditions, influence from hysteresis is rejected, the systems are robustly stable and output tracking performance can be realized.Finally, the effectiveness of the proposed method is confirmed by numerical simulations. 展开更多
关键词 Index Terms-Generalized PI hysteresis operator based robustright coprime factorization robust nonlinear control.
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Reduced Model Based Control of Two Link Flexible Space Robot 被引量:11
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作者 Amit Kumar Pushparaj Mani Pathak Nagarajan Sukavanam 《Intelligent Control and Automation》 2011年第2期112-120,共9页
Model based control schemes use the inverse dynamics of the robot arm to produce the main torque component necessary for trajectory tracking. For model-based controller one is required to know the model parameters acc... Model based control schemes use the inverse dynamics of the robot arm to produce the main torque component necessary for trajectory tracking. For model-based controller one is required to know the model parameters accurately. This is a very difficult task especially if the manipulator is flexible. So a reduced model based controller has been developed, which requires only the information of space robot base velocity and link parameters. The flexible link is modeled as Euler Bernoulli beam. To simplify the analysis we have considered Jacobian of rigid manipulator. Bond graph modeling is used to model the dynamics of the system and to devise the control strategy. The scheme has been verified using simulation for two links flexible space manipulator. 展开更多
关键词 Flexible Space ROBOTS BOND GRAPH Modeling REDUCED Model based controlLER Euler-Bernoulli Beam
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Controlled low-strength material incorporating recycled fine aggregate from urban red brick based construction waste 被引量:9
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作者 Ran Jin Zhang Jinxi +2 位作者 Yang Mijia Jia Dongdong Lu Shengdi 《Journal of Southeast University(English Edition)》 EI CAS 2017年第4期496-501,共6页
Sixteen controlled low-strength material( CLSM)mixtures with various cement-to-sand( C/Sa) ratios and water-to-solid( W/So) ratios were prepared using recycled fine aggregate from urban red brick based construction wa... Sixteen controlled low-strength material( CLSM)mixtures with various cement-to-sand( C/Sa) ratios and water-to-solid( W/So) ratios were prepared using recycled fine aggregate from urban red brick based construction waste.The fluidity and bleeding of the fresh CLSM mixtures were measured via the modified test methods, and the hardened CLSM mixtures were then molded to evaluate their compressive strength and durability. The results showthat the fluidity of the fresh CLSM mixtures is 105 to 227 mm with the corresponding bleeding rate of 3. 7% to 15. 5%, which increases with the increase in fluidity. After aging for 28 d,the compressive strength of the hardened CLSM mixtures reaches 1. 15 to 13. 96 M Pa, and their strength can be further enhanced with longer curing ages. Additionally, the strength increases with the increase of the C/Sa ratio, and decreases with the increase of the W/So ratio under the same curing age. Based on the obtained compressive strength, a fitting model for accurately predicting the compressive strength of the CLSM mixtures was established, which takes into account the above two independent variables( C/Sa and W/So ratios).M oreover, the durability of the hardened CLSM mixtures is enhanced for samples with higher C/Sa ratios. 展开更多
关键词 controlled low-strength material recycled fine aggregate fo m urban red brick based construction waste fluidity bleeding compressive strength durability
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Base Pressure Control with Semi-Circular Ribs at Critical Mach Number
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作者 Ambareen Khan Sher Afghan Khan +2 位作者 Mohammed Nishat Akhtar Abdul Aabid Muneer Baig 《Fluid Dynamics & Materials Processing》 EI 2024年第9期2007-2028,共22页
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
关键词 base pressure nozzle pressure ratio base drag sonic Mach number passive control
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Hybrid event based control architecture for tele-robotic systems controlled through Internet 被引量:1
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作者 李晓明 杨灿军 +1 位作者 陈鹰 胡旭东 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2004年第3期47-53,共7页
A new hybrid event based control architecture for tele-robotic systems controlled through the Internet is pro-posed in this paper. Different from the traditional event based control method, the new framework does not ... A new hybrid event based control architecture for tele-robotic systems controlled through the Internet is pro-posed in this paper. Different from the traditional event based control method, the new framework does not require every part of the system to be strictly event synchronized. Instead, it allows time referenced control components to be integrated into this framework, which makes it more convenient to develop Internet based control systems. Since there are two reference variables, time and event, in this architecture, how to coordinate these components with different references to keep the stability of the whole system is discussed in detail in this paper. To verify this new idea, an experiment was conducted to control the end effector of a PUMA robot tracking a continuous state trajectory given on-line by the remote operator. Ex-perimental results confirmed the stability of such systems being controlled through the Internet in real-time. 展开更多
关键词 Tele-robot EVENT based control System INTEGRATION
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Reliability Analysis of Controller Area Network Based Systems—A Review 被引量:2
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作者 Gerardine Immaculate Mary Zachariah C. Alex Lawrence Jenkins 《International Journal of Communications, Network and System Sciences》 2013年第4期155-166,共12页
This paper reviews the research work done on the Reliability Analysis of Controller Area Network (CAN) based systems. During the last couple of decades, real-time researchers have extended schedulability analysis to a... This paper reviews the research work done on the Reliability Analysis of Controller Area Network (CAN) based systems. During the last couple of decades, real-time researchers have extended schedulability analysis to a mature technique which for nontrivial systems can be used to determine whether a set of tasks executing on a single CPU or in a distributed system will meet their deadlines or not [1-3]. The main focus of the real-time research community is on hard real-time systems, and the essence of analyzing such systems is to investigate if deadlines are met in a worst case scenario. Whether this worst case actually will occur during execution, or if it is likely to occur, is not normally considered. Reliability modeling, on the other hand, involves study of fault models, characterization of distribution functions of faults and development of methods and tools for composing these distributions and models in estimating an overall reliability figure for the system [4]. This paper presents the research work done on reliability analysis developed with a focus on Controller-Area-Network-based automotive systems. 展开更多
关键词 Reliability Analysis of controlLER Area Network based SYSTEMS FAULT-TOLERANT CAN based SYSTEMS
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Online Learning Control for Harmonics Reduction Based on Current Controlled Voltage Source Power Inverters 被引量:2
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作者 Naresh Malla Ujjwol Tamrakar +2 位作者 Dipesh Shrestha Zhen Ni Reinaldo Tonkoski 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第3期447-457,共11页
Nonlinear loads in the power distribution system cause non-sinusoidal currents and voltages with harmonic components.Shunt active filters(SAF) with current controlled voltage source inverters(CCVSI) are usually used t... Nonlinear loads in the power distribution system cause non-sinusoidal currents and voltages with harmonic components.Shunt active filters(SAF) with current controlled voltage source inverters(CCVSI) are usually used to obtain balanced and sinusoidal source currents by injecting compensation currents.However,CCVSI with traditional controllers have a limited transient and steady state performance.In this paper,we propose an adaptive dynamic programming(ADP) controller with online learning capability to improve transient response and harmonics.The proposed controller works alongside existing proportional integral(PI) controllers to efficiently track the reference currents in the d-q domain.It can generate adaptive control actions to compensate the PI controller.The proposed system was simulated under different nonlinear(three-phase full wave rectifier) load conditions.The performance of the proposed approach was compared with the traditional approach.We have also included the simulation results without connecting the traditional PI control based power inverter for reference comparison.The online learning based ADP controller not only reduced average total harmonic distortion by 18.41%,but also outperformed traditional PI controllers during transients. 展开更多
关键词 Adaptive dynamic programming(ADP) current controlled voltage source power inverter(CCVSI) online learning based controller neural networks shunt active filter(SAF) total harmonic distortion(THD)
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Consistency maintenance for constraint in role-based access control model 被引量:3
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作者 韩伟力 陈刚 +1 位作者 尹建伟 董金祥 《Journal of Zhejiang University Science》 CSCD 2002年第3期292-297,共6页
Constraint is an important aspect of role based access control and is sometimes argued to be the principal motivation for role based access control (RBAC). But so far few authors have discussed consistency maintenan... Constraint is an important aspect of role based access control and is sometimes argued to be the principal motivation for role based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD PDM, an enterprise oriented product data management (PDM) system. 展开更多
关键词 Consistency maintenance Role based access control Product data management CONSTRAINT
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Application of control volume based finite element method for solving the black-oil fluid equations 被引量:1
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作者 GHOREISHIAN AMIRI S A SADRNEJAD S A +1 位作者 GHASEMZADEH H MONTAZERI G H 《Petroleum Science》 SCIE CAS CSCD 2013年第3期361-372,共12页
This is the second paper of a series where we introduce a control volume based finite element method (CVFEM) to simulate multiphase flow in porous media. This is a fully conservative method able to deal with unstruc... This is the second paper of a series where we introduce a control volume based finite element method (CVFEM) to simulate multiphase flow in porous media. This is a fully conservative method able to deal with unstructured grids which can be used for representing any complexity of reservoir geometry and its geological objects in an accurate and efficient manner. In order to deal with the inherent heterogeneity of the reservoirs, all operations related to discretization are performed at the element level in a manner similar to classical finite element method (FEM). Moreover, the proposed method can effectively reduce the so-called grid orientation effects. In the first paper of this series, we presented this method and its application for incompressible and immiscible two-phase flow simulation in homogeneous and heterogeneous porous media. In this paper, we evaluate the capability of the method in the solution of highly nonlinear and coupled partial differential equations by simulating hydrocarbon reservoirs using the black-oil model. Furthermore, the effect of grid orientation is investigated by simulating a benchmark waterflooding problem. The numerical results show that the formulation presented here is efficient and accurate for solving the bubble point and three-phase coning problems. 展开更多
关键词 control volume based finite element black-oil model grid orientation porous media
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Application of PID Controller Based on BP Neural Network in Export Steam’s Temperature Control System 被引量:4
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作者 朱增辉 孙慧影 《Journal of Measurement Science and Instrumentation》 CAS 2011年第1期84-87,共4页
By combining the Back-Propagation (BP) neural network with conventional proportional Integral Derivative (PID) controller, a new temperature control strategy of the export steam in supercritical electric power pla... By combining the Back-Propagation (BP) neural network with conventional proportional Integral Derivative (PID) controller, a new temperature control strategy of the export steam in supercritical electric power plant is put forward. This scheme can effectively overcome the large time delay, inertia of the export steam and the influencee of object in varying operational parameters. Thus excellent control quality is obtaitud. The present paper describes the development and application of neural network based controller to control the temperature of the boiler's export steam. Through simulation in various situations, it validates that the control quality of this control system is apparently superior to the conventional PID control system. 展开更多
关键词 PID controller based on BP neural network supercritical power unit export steam temperature large timedelay
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Numerical Analysis of a Microjet-Based Method for Active Flow Control in Convergent-Divergent Nozzles with a Sudden Expansion 被引量:1
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作者 Abdul Aabid Sher Afghan Khan Muneer Baig 《Fluid Dynamics & Materials Processing》 EI 2022年第6期1877-1900,共24页
A method based on microjets is implemented to control the flow properties in a convergent-divergent nozzle undergoing a sudden expansion.Three different variants of this active control technique are explored numerical... A method based on microjets is implemented to control the flow properties in a convergent-divergent nozzle undergoing a sudden expansion.Three different variants of this active control technique are explored numerically by means of a finite-volume method for compressible fluid flow:with the first one,the control is implemented at the base,with the second at the wall,while the third one may be regarded as a combination of these.When jets are over-expanded,the control is not very effective.However,when a favourable pressure gradient is established in the nozzle,the control becomes effective,leading to an increase in the base pressure. 展开更多
关键词 base pressure supersonic flow CFD mach number microjet control
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Research on the principle of space high-precision temperature control system of liquid crystals based Stokes polarimeter 被引量:1
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作者 Xin-Wei Zhang Yang Zhang +2 位作者 Jia-Ben Lin Jun-Feng Hou Yuan-Yong Deng 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第1期97-104,共8页
The magnetic field is one of the most important parameters in solar physics,and a polarimeter is the key device to measure the solar magnetic field.Liquid crystals based Stokes polarimeter is a novel technology,and wi... The magnetic field is one of the most important parameters in solar physics,and a polarimeter is the key device to measure the solar magnetic field.Liquid crystals based Stokes polarimeter is a novel technology,and will be applied for magnetic field measurement in the first space-based solar observatory satellite developed by China,Advanced Space-based Solar Observatory.However,the liquid crystals based Stokes polarimeter in space is not a mature technology.Therefore,it is of great scientific significance to study the control method and characteristics of the device.The retardation produced by a liquid crystal variable retarder is sensitive to the temperature,and the retardation changes 0.09°per 0.10℃.The error in polarization measurement caused by this change is 0.016,which affects the accuracy of magnetic field measurement.In order to ensure the stability of its performance,this paper proposes a high-precision temperature control system for liquid crystals based Stokes polarimeter in space.In order to optimize the structure design and temperature control system,the temperature field of liquid crystals based Stokes polarimeter is analyzed by the finite element method,and the influence of light on the temperature field of the liquid crystal variable retarder is analyzed theoretically.By analyzing the principle of highprecision temperature measurement in space,a high-precision temperature measurement circuit based on integrated operational amplifier,programmable amplifier and 12 bit A/D is designed,and a high-precision space temperature control system is developed by applying the integral separation PI temperature control algorithm and PWM driving heating films.The experimental results show that the effect of temperature control is accurate and stable,whenever the liquid crystals based Stokes polarimeter is either in the air or vacuum.The temperature stability is within±0.0150℃,which demonstrates greatly improved stability for the liquid crystals based Stokes polarimeter. 展开更多
关键词 liquid crystals based Stokes polarimeter high-precision temperature measurement space high-precision temperature control temperature field analysis PID control
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