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Identifying a competency improvement strategy for infection prevention and control professionals:A rapid systematic review and cluster analysis
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作者 Nuo Chen Shunning Li +3 位作者 Zhengling Kuang Ting Gong Weilong Zhou Ying Wang 《Health Care Science》 2024年第1期53-66,共14页
Remarkable progress has been made in infection prevention and control(IPC)in many countries,but some gaps emerged in the context of the coronavirus disease 2019(COVID-19)pandemic.Core capabilities such as standard cli... Remarkable progress has been made in infection prevention and control(IPC)in many countries,but some gaps emerged in the context of the coronavirus disease 2019(COVID-19)pandemic.Core capabilities such as standard clinical precautions and tracing the source of infection were the focus of IPC in medical institutions during the pandemic.Therefore,the core competences of IPC professionals during the pandemic,and how these contributed to successful prevention and control of the epidemic,should be studied.To investigate,using a systematic review and cluster analysis,fundamental improvements in the competences of infection control and prevention professionals that may be emphasized in light of the COVID-19 pandemic.We searched the PubMed,Embase,Cochrane Library,Web of Science,CNKI,WanFang Data,and CBM databases for original articles exploring core competencies of IPC professionals during the COVID-19 pandemic(from January 1,2020 to February 7,2023).Weiciyun software was used for data extraction and the Donohue formula was followed to distinguish high-frequency technical terms.Cluster analysis was performed using the within-group linkage method and squared Euclidean distance as the metric to determine the priority competencies for development.We identified 46 studies with 29 high-frequency technical terms.The most common term was“infection prevention and control training”(184 times,17.3%),followed by“hand hygiene”(172 times,16.2%).“Infection prevention and control in clinical practice”was the most-reported core competency(367 times,34.5%),followed by“microbiology and surveillance”(292 times,27.5%).Cluster analysis showed two key areas of competence:Category 1(program management and leadership,patient safety and occupational health,education and microbiology and surveillance)and Category 2(IPC in clinical practice).During the COVID-19 pandemic,IPC program management and leadership,microbiology and surveillance,education,patient safety,and occupational health were the most important focus of development and should be given due consideration by IPC professionals. 展开更多
关键词 infection prevention and control professionals competency improvement cluster analysis COVID-19 REVIEW
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The MDOF equivalent linear system and its applications in seismic analysis and design of framed structures
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作者 E.V.Muho N.A.Kalapodis +1 位作者 G.A.Papagiannopoulos D.E.Beskos 《Resilient Cities and Structures》 2024年第4期107-125,共19页
This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear struc... This paper reviews the applications of the multi degree-of-freedom(MDOF)equivalent linear system in seismic analysis and design of planar steel and reinforced concrete framed structures.An equivalent MDOF linear structure,analogous to the original MDOF nonlinear structure,is constructed,which has the same mass and elastic stiffness as the original structure and modal damping ratios that account for the effects of geometrical and material nonlinearities.The equivalence implies a balance between the viscous damping work of the equivalent linear structure and that of the nonlinearities in the original nonlinear structure.This work balance is established with the aid of a transfer function in the frequency domain.Thus,equivalent modal damping ratios can be explicitly determined in terms of the period and deformation levels of the structure as well as the soil types.Use of these equivalent modal damping ratios can help address a variety of seismic analysis and design problems associated with planar steel and reinforced concrete framed structures in a rational and accurate manner.These include force-based seismic design with the aid of acceleration response spectra characterized by high amounts of damping,improved direct displacement-based seismic design and the development of advanced seismic intensity measures.The equivalent modal damping ratios are also utilized in the context of linear modal analysis for the definition and construction of the MDOF response spectrum.Furthermore,the equivalent modal damping ratios are employed in a seismic retrofit method for steel-framed structures with viscous dampers.Finally,it is demonstrated that modal behavior(or strength reduction)factors can be easily constructed based on these modal damping ratios for a more rational and accurate force-based seismic design,including the determination of inelastic displacement profiles. 展开更多
关键词 Seismic analysis Seismic design Steel-framed structures Reinforced concrete-framed structures MDof equivalent linear system Modal damping ratios Modal strength reduction factors Seismic intensity measures MDof response spectrum
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Design approaches for active,semi-active and passive control systems based on analysis of characteristics of active control force 被引量:4
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作者 Ou Jinping Li Hui 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2009年第4期493-506,共14页
In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed: (1) active control can provide significant... In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed: (1) active control can provide significantly superior supplemental damping to a building, but causes a small frequency shift; (2) the linear quadratic regulator (LQR)-based control force is composed of an elastic restoring force component and a damping force component, where the damping force is almost identical to the total control force, however, the elastic restoring force is very small; and (3) the active control forces prevent mction most of the time during the entire control process. These three characteristics imply that active control systems connected to adjacent levels of a building behave like passive damping devices with adjustable parameters, namely damping characteristics in an active control, which is the mechanism used by semi-active control devices to reach similar performance as active control systems. Two indices are defined to quantify the damping characteristics of control forces in active control systems. These two indices can also be used to quantify the capacity of semi-active control to achieve the perfonrlance of active control. Based on the above observations, two principles are founded for optimization of parameters of semi-active control devices and passive dampers. The first is that the maximum output force of a semi-active or passive device to be designed is identical to an active device, called "design principle". The other is the response equivalent principle, which states that the response of a building with semi-active or passive devices is the same as with active devices when the same maximum output force is applied. The design procedure for semi-active control devices and passive dampers is described in detail. Finally, numerical simulations of two benchmark problems is conducted to demonstrate the damping characteristics of active control and investigate the capacity of semi-active control to achieve the same performance as active control. 展开更多
关键词 active control semi-active control smart control DAMPING design approach
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Reliability and sensitivity analysis of loop-designed security and stability control system in interconnected power systems 被引量:5
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作者 Shenghu Li Huimin Zhou +2 位作者 Yunsong Yan Wei Han Jianfeng Ren 《Global Energy Interconnection》 EI CAS CSCD 2022年第5期501-511,共11页
Security and stability control system(SSCS)in power systems involves collecting information and sending the decision from/to control stations at different layers;the tree structure of the SSCS requires more levels.Fai... Security and stability control system(SSCS)in power systems involves collecting information and sending the decision from/to control stations at different layers;the tree structure of the SSCS requires more levels.Failure of a station or channel can cause all the execution stations(EXs)to be out of control.The randomness of the controllable capacity of the EXs increases the difficulty of the reliability evaluation of the SSCS.In this study,the loop designed SSCS and reliability analysis are examined for the interconnected systems.The uncertainty analysis of the controllable capacity based on the evidence theory for the SSCS is proposed.The bidirectional and loop channels are introduced to reduce the layers and stations of the existing SSCS with tree configuration.The reliability evaluation and sensitivity analysis are proposed to quantify the controllability and vulnerable components for the SSCS in different configurations.By aiming at the randomness of the controllable capacity of the EXs,the uncertainty analysis of the controllable capacity of the SSCS based on the evidence theory is proposed to quantify the probability of the SSCS for balancing the active power deficiency of the grid. 展开更多
关键词 Security and stability control system(SSCS) Loop design controlLABILITY VULNERABILITY Interconnected power systems Evidence theory Uncertainty controllable capacity.
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Design, Analysis and Real-time Implementation of Networked Predictive Control Systems 被引量:6
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作者 LIU Guo-Ping SUN Jian ZHAO Yun-Bo 《自动化学报》 EI CSCD 北大核心 2013年第11期1769-1777,共9页
这份报纸用预兆的控制策略涉及设计,分析和联网的控制系统的即时实现。联网的控制系统的特征的分析被详细说明,它证明一个联网的控制系统与常规控制系统不同。完成靠近环的联网的控制系统的需要的性能,联网的预兆的控制计划被介绍。... 这份报纸用预兆的控制策略涉及设计,分析和联网的控制系统的即时实现。联网的控制系统的特征的分析被详细说明,它证明一个联网的控制系统与常规控制系统不同。完成靠近环的联网的控制系统的需要的性能,联网的预兆的控制计划被介绍。设计,稳定性分析和联网的预兆的控制系统的即时实现被学习。它被联网的预兆的控制计划能补偿随机的网络通讯延期和数据退学学生的模拟和实际实验说明,完成需要的控制性能并且有好靠近环的稳定性。 展开更多
关键词 闭环网络控制系统 预测控制系统 实时实现 设计 预测控制策略 控制方案 网络预测 控制性能
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Interaction Analysis and Decomposition Principle for Control Structure Design of Large-scale Systems
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作者 罗雄麟 刘雨波 许锋 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第1期59-71,共13页
Industrial processes are mostly large-scale systems with high order.They use fully centralized control strategy,the parameters of which are difficult to tune.In the design of large-scale systems,the decomposition acco... Industrial processes are mostly large-scale systems with high order.They use fully centralized control strategy,the parameters of which are difficult to tune.In the design of large-scale systems,the decomposition according to the interaction between input and output variables is the first step and the basis for the selection of control structure.In this paper,the decomposition principle of processes in large-scale systems is proposed for the design of control structure.A new variable pairing method is presented,considering the steady-state information and dynamic response of large-scale system.By selecting threshold values,the related matrix can be transformed into the adjoining matrixes,which directly measure the couple among different loops.The optimal number of controllers can be obtained after decomposing the large-scale system.A practical example is used to demonstrate the validity and feasibility of the proposed interaction decomposition principle in process large-scale systems. 展开更多
关键词 control structure interaction analysis interaction decomposition threshold value
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Vibration Control of the Rail Grinding Vehicle with Abrasive Belt Based on Structural Optimization and Lightweight Design
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作者 Wengang Fan Shuai Zhang +2 位作者 Zhiwei Wu Yi Liu Jiangnan Yu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期311-337,共27页
As a new grinding and maintenance technology,rail belt grinding shows significant advantages in many applications The dynamic characteristics of the rail belt grinding vehicle largely determines its grinding performan... As a new grinding and maintenance technology,rail belt grinding shows significant advantages in many applications The dynamic characteristics of the rail belt grinding vehicle largely determines its grinding performance and service life.In order to explore the vibration control method of the rail grinding vehicle with abrasive belt,the vibration response changes in structural optimization and lightweight design are respectively analyzed through transient response and random vibration simulations in this paper.Firstly,the transient response simulation analysis of the rail grinding vehicle with abrasive belt is carried out under operating conditions and non-operating conditions.Secondly,the vibration control of the grinding vehicle is implemented by setting vibration isolation elements,optimizing the structure,and increasing damping.Thirdly,in order to further explore the dynamic characteristics of the rail grinding vehicle,the random vibration simulation analysis of the grinding vehicle is carried out under the condition of the horizontal irregularity of the American AAR6 track.Finally,by replacing the Q235 steel frame material with 7075 aluminum alloy and LA43M magnesium alloy,both vibration control and lightweight design can be achieved simultaneously.The results of transient dynamic response analysis show that the acceleration of most positions in the two working conditions exceeds the standard value in GB/T 17426-1998 standard.By optimizing the structure of the grinding vehicle in three ways,the average vibration acceleration of the whole car is reduced by about 55.1%from 15.6 m/s^(2) to 7.0 m/s^(2).The results of random vibration analysis show that the grinding vehicle with Q235 steel frame does not meet the safety conditions of 3σ.By changing frame material,the maximum vibration stress of the vehicle can be reduced from 240.7 MPa to 160.0 MPa and the weight of the grinding vehicle is reduced by about 21.7%from 1500 kg to 1175 kg.The modal analysis results indicate that the vibration control of the grinding vehicle can be realized by optimizing the structure and replacing the materials with lower stiffness under the premise of ensuring the overall strength.The study provides the basis for the development of lightweight,diversified and efficient rail grinding equipment. 展开更多
关键词 Vibration control Dynamic characteristics Structural optimization Lightweight design Modal analysis
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Dynamical analysis,control,boundedness,and prediction for a fractional-order financial risk system
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作者 Kehao Yang Song Zheng +4 位作者 Tianhu Yu Aceng Sambas Muhamad Deni Johansyah Hassan Saberi-Nik Mohamad Afendee Mohamed 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期223-235,共13页
This paper delves into the dynamical analysis,chaos control,Mittag–Leffler boundedness(MLB),and forecasting a fractional-order financial risk(FOFR)system through an absolute function term.To this end,the FOFR system ... This paper delves into the dynamical analysis,chaos control,Mittag–Leffler boundedness(MLB),and forecasting a fractional-order financial risk(FOFR)system through an absolute function term.To this end,the FOFR system is first proposed,and the adomian decomposition method(ADM)is employed to resolve this fractional-order system.The stability of equilibrium points and the corresponding control schemes are assessed,and several classical tools such as Lyapunov exponents(LE),bifurcation diagrams,complexity analysis(CA),and 0–1 test are further extended to analyze the dynamical behaviors of FOFR.Then the global Mittag–Leffler attractive set(MLAS)and Mittag–Leffler positive invariant set(MLPIS)for the proposed financial risk(FR)system are discussed.Finally,a proficient reservoir-computing(RC)method is applied to forecast the temporal evolution of the complex dynamics for the proposed system,and some simulations are carried out to show the effectiveness and feasibility of the present scheme. 展开更多
关键词 FofR system dynamical analysis control BOUNDEDNESS forecasting
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Path Tracking Controller Design of Automated Parking Systems via NMPC with an Instructible Solution
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作者 Liang Chen Zhaobo Qin +2 位作者 Manjiang Hu Yougang Bian Xiaoyan Peng 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期353-367,共15页
Parking difficulties have become a social issue that people have to solve.Automated parking system is practicable for quick par operations without a driver which can also greatly reduces the probability of parking acc... Parking difficulties have become a social issue that people have to solve.Automated parking system is practicable for quick par operations without a driver which can also greatly reduces the probability of parking accidents.The paper proposes a Lyapunov-based nonlinear model predictive controller embedding an instructable solution which is generated by the modified rear-wheel feedback method(RF-LNMPC)in order to improve the overall path tracking accuracy in parking conditions.Firstly,A discrete-time RF-LNMPC considering the position and attitude of the parking vehicle is proposed to increase the success rate of automated parking effectively.Secondly,the RF-LNMPC problem with a multi-objective cost function is solved by the Interior-Point Optimization,of which the iterative initial values are described as the instructable solutions calculated by combining modified rear-wheel feedback to improve the performance of local optimal solution.Thirdly,the details on the computation of the terminal constraint and terminal cost for the linear time-varying case is presented.The closed-loop stability is verified via Lyapunov techniques by considering the terminal constraint and terminal cost theoretically.Finally,the proposed RF-LNMPC is implemented on a selfdriving Lincoln MKZ platform and the experiment results have shown improved performance in parallel and vertical parking conditions.The Monte Carlo analysis also demonstrates good stability and repeatability of the proposed method which can be applied in practical use in the near future. 展开更多
关键词 Automated parking Path tracking controller Nonlinear model predictive control Monte Carlo analysis
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The prediction of projectile-target intersection for moving tank based on adaptive robust constraint-following control and interval uncertainty analysis
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作者 Cong Li Xiuye Wang +2 位作者 Yuze Ma Fengjie Xu Guolai Yang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期351-363,共13页
To improve the hit probability of tank at high speed,a prediction method of projectile-target intersection based on adaptive robust constraint-following control and interval uncertainty analysis is proposed.The method... To improve the hit probability of tank at high speed,a prediction method of projectile-target intersection based on adaptive robust constraint-following control and interval uncertainty analysis is proposed.The method proposed provides a novel way to predict the impact point of projectile for moving tank.First,bidirectional stability constraints and stability constraint-following error are constructed using the Udwadia-Kalaba theory,and an adaptive robust constraint-following controller is designed considering uncertainties.Second,the exterior ballistic ordinary differential equation with uncertainties is integrated into the controller,and the pointing control of stability system is extended to the impact-point control of projectile.Third,based on the interval uncertainty analysis method combining Chebyshev polynomial expansion and affine arithmetic,a prediction method of projectile-target intersection is proposed.Finally,the co-simulation experiment is performed by establishing the multi-body system dynamic model of tank and mathematical model of control system.The results demonstrate that the prediction method of projectile-target intersection based on uncertainty analysis can effectively decrease the uncertainties of system,improve the prediction accuracy,and increase the hit probability.The adaptive robust constraint-following control can effectively restrain the uncertainties caused by road excitation and model error. 展开更多
关键词 Tank stability control Constraint-following Adaptive robust control Uncertainty analysis Prediction of projectile-target intersection
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Process design and intensification of multicomponent azeotropes special distillation separation via molecular simulation and system optimization
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作者 Chunliang Liu Jianhui Zhong +5 位作者 Ranran Wei Jiuxu Ruan Kaicong Wang Zhaoyou Zhu Yinglong Wang Limei Zhong 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第7期24-44,共21页
This work provides an overview of distillation processes,including process design for different distillation processes,selection of entrainers for special distillation processes,system integration and intensification ... This work provides an overview of distillation processes,including process design for different distillation processes,selection of entrainers for special distillation processes,system integration and intensification of distillation processes,optimization of process parameters for distillation processes and recent research progress in dynamic control strategies.Firstly,the feasibility of using thermodynamic topological theories such as residual curve,phase equilibrium line and distillation boundary line to analyze different separation regions is discussed,and the rationality of distillation process design is discussed by using its feasibility.Secondly,the application of molecular simulation methods such as molecular dynamics simulation and quantum chemical calculation in the screening of entrainer is discussed for the extractive distillation process.The thermal coupling mechanism of different distillation processes is used to explore the process of different process intensifications.Next,a mixed integer nonlinear optimization strategy for the distillation process based on different algorithms is introduced.Finally,the improvement of dynamic control strategies for different distillation processes in recent years is summarized.This work focuses on the application of process intensification and system optimization in the design of distillation process,and analyzes the challenges,prospects,and development trends of distillation technology in the separation of multicomponent azeotropes. 展开更多
关键词 Azeotrope separation Process design Optimization algorithm Process integration Dynamic control Entrainer selection
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Bifurcation analysis and control study of improved full-speed differential model in connected vehicle environment
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作者 艾文欢 雷正清 +2 位作者 李丹洋 方栋梁 刘大为 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期245-266,共22页
In recent years, the traffic congestion problem has become more and more serious, and the research on traffic system control has become a new hot spot. Studying the bifurcation characteristics of traffic flow systems ... In recent years, the traffic congestion problem has become more and more serious, and the research on traffic system control has become a new hot spot. Studying the bifurcation characteristics of traffic flow systems and designing control schemes for unstable pivots can alleviate the traffic congestion problem from a new perspective. In this work, the full-speed differential model considering the vehicle network environment is improved in order to adjust the traffic flow from the perspective of bifurcation control, the existence conditions of Hopf bifurcation and saddle-node bifurcation in the model are proved theoretically, and the stability mutation point for the stability of the transportation system is found. For the unstable bifurcation point, a nonlinear system feedback controller is designed by using Chebyshev polynomial approximation and stochastic feedback control method. The advancement, postponement, and elimination of Hopf bifurcation are achieved without changing the system equilibrium point, and the mutation behavior of the transportation system is controlled so as to alleviate the traffic congestion. The changes in the stability of complex traffic systems are explained through the bifurcation analysis, which can better capture the characteristics of the traffic flow. By adjusting the control parameters in the feedback controllers, the influence of the boundary conditions on the stability of the traffic system is adequately described, and the effects of the unstable focuses and saddle points on the system are suppressed to slow down the traffic flow. In addition, the unstable bifurcation points can be eliminated and the Hopf bifurcation can be controlled to advance, delay, and disappear,so as to realize the control of the stability behavior of the traffic system, which can help to alleviate the traffic congestion and describe the actual traffic phenomena as well. 展开更多
关键词 bifurcation analysis vehicle queuing bifurcation control Hopf bifurcation
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Advances in stability analysis and optimization design of large underground caverns under high geostress condition
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作者 Long Li Quan Jiang +2 位作者 Qingfu Huang Tianbing Xiang Jian Liu 《Deep Resources Engineering》 2024年第3期82-96,共15页
The demand for underground space and sustainable energy has driven the need for underground structures.Large underground caverns,being an underground structure carrier,offers a feasible solution.However,the stability ... The demand for underground space and sustainable energy has driven the need for underground structures.Large underground caverns,being an underground structure carrier,offers a feasible solution.However,the stability analysis and optimization design of large underground caverns is always a great challenge due to the high geostress,complicated rock condition,and high sidewalls and large spans in size.By collecting and reviewing a large amount of relevant research literature from 1970 to 2023,the efforts on the advances in stability analysis methods and optimization design of large underground caverns are described,then the research trends in this field through keywords were found and typical deformation and break modes of large underground caverns with high geostress are summarized.The review reveals that stability analysis and optimization are the recent active research topics.There are seven typical deformation and break modes of large underground caverns under high geostress,four stability analysis methods and four theories of optimization design of large under-ground caverns.With the progress of science and technology and society,intelligent design,mechanized con-struction and greening construction are the development trend in this field.The research results can provide a constructive reference for the stability analysis and optimization design of large underground caverns under high geostress. 展开更多
关键词 Underground caverns Stability analysis Optimization design High geostress
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Study on Influencing Factors and Control Points of Design Estimate of Landscaping Engineering
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作者 Dan Zhang Meng Wu +1 位作者 Jiashuo Zhao Jie Di 《Journal of Architectural Research and Development》 2024年第5期13-19,共7页
In recent years,China’s landscaping projects have developed vigorously,and the growth rate of urban garden green space areas has been maintained at about 5%.Overall,with the development of the national economy and th... In recent years,China’s landscaping projects have developed vigorously,and the growth rate of urban garden green space areas has been maintained at about 5%.Overall,with the development of the national economy and the support of macro policies,people’s demand for close to nature and beautify the environment is gradually increasing,which has brought new growth momentum for the development of the landscaping industry.Simultaneously,from the perspective of future economic development and urban development,the landscaping industry still has a lot of room for development.However,with the rapid development of landscape engineering,the problem of cost control of landscape engineering is becoming more prominent,the phenomenon of budget overestimation is common,and there are many factors affecting the cost of landscape engineering,which brings difficulties and challenges to the analysis of its influencing factors and cost management.How to scientifically analyze the influencing factors and control the cost has become an important link in the landscaping project.To solve the above problems,this paper takes the design stage of landscaping engineering as the background,takes the design estimate of landscaping engineering as the research object,through literature research and data collection,fully excavates the main influencing factors of the design estimate stage of landscaping engineering,analyzes the key points of cost control,and provides reference ideas and directions for the later cost management and control. 展开更多
关键词 Landscape engineering design estimate Main influencing factors Cost control
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Synthetic analysis of meteorological elements for the sea fogs occurred in northwest the Yellow Sea under low pressure control and comparison with sea fogs occurred under high pressure control in summer
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作者 WANG Kaiyue MA Zheng +3 位作者 MIAO Qingsheng ZHAO Binru ZHANG Zengjian LI Cheng 《Marine Science Bulletin》 2024年第1期1-18,共18页
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
关键词 sea fog under the low pressure control sea fog under the high pressure control northwest of the Yellow Sea synthetic analysis transient method
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Error analysis and a new steering law design for spacecraft control system using SGCMGs 被引量:7
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作者 Jin Jin Jing-Rui Zhang Zao-Zhen Liu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第5期803-808,共6页
Based on the singular value decomposition theory,this paper analyzed the mechanism of escaping/avoiding singularity using generalized and weighted singularity-robust steering laws for a spacecraft that uses single gim... Based on the singular value decomposition theory,this paper analyzed the mechanism of escaping/avoiding singularity using generalized and weighted singularity-robust steering laws for a spacecraft that uses single gimbal control moment gyros (SGCMGs) as the actuator for the attitude control system.The expression of output-torque error is given at the point of singularity,proving the incompatible relationship between the gimbal rate and the output-torque error.The method of establishing a balance between the gimbal rate and the output-torque error is discussed,and a new steering law is designed.Simulation results show that the proposed steering law can effectively drive SGCMGs to escape away from singularities. 展开更多
关键词 Single gimbal control moment gyros (SGCMGs) Attitude control Singularity analysis Steering law
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Analysis of PROFIBUS-DP Network Delay and Its Influence on the Performance of Control Systems 被引量:5
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作者 TAO Jun WANG Zhan-lin 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第5期877-882,共6页
This paper analyzes PROFIBUS-DP network delay in detail and presents the calculational formula of its maximum time-delay, which is significant to the research of PROFIBUS-DP. At the same time, the paper puts forward a... This paper analyzes PROFIBUS-DP network delay in detail and presents the calculational formula of its maximum time-delay, which is significant to the research of PROFIBUS-DP. At the same time, the paper puts forward a method of simplifying the network induced time-varying indeterminate system according to the features of the network. Through the analysis of a pump-control-motor system which is composed of PROFIBUS-DP network, it illustrates the network's influence on the performance of control systems. This method helps to design and analyze the network's influence on the performance of control systems, which is of considerable practical value in a time when network control systern is widely used. 展开更多
关键词 network delay analysis network control system deterministic control
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Integrated Design and Accuracy Analysis of Star Sensor and Gyro on the Same Benchmark for Satellite Attitude Determination System 被引量:2
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作者 Bowen Hou Zhangming He +1 位作者 Haiyin Zhou Jiongqi Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第4期1074-1080,共7页
As an important sensor in the navigation systems,star sensors and the gyro play important roles in spacecraft attitude determination system.Complex environmental factors are the main sources of error in attitude deter... As an important sensor in the navigation systems,star sensors and the gyro play important roles in spacecraft attitude determination system.Complex environmental factors are the main sources of error in attitude determination.The error influence of different benchmarks and the disintegration mode between the star sensor and the gyro is analyzed in theory.The integrated design of the star sensor and the gyro on the same benchmark can effectively avoid the error influence and improves the spacecraft attitude determination accuracy.Simulation results indicate that when the stars sensor optical axis vectors overlap the reference coordinate axis of the gyro in the same benchmark,the attitude determination accuracy improves. 展开更多
关键词 ACCURACY analysis ATTITUDE determination GYRO integrated design SAME BENCHMARK STAR sensor
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Rationale and Design of the Randomized Controlled Trial of Intensive Versus Usual ECG Screening for Atrial Fibrillation in Elderly Chinese by an Automated ECG System in Community Health Centers in Shanghai(AF-CATCH) 被引量:2
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作者 Ji-Guang Wang Yi Chen +2 位作者 Qi-Fang Huang Yan Li Ben Freedman 《Cardiovascular Innovations and Applications》 2017年第B02期273-277,共5页
Objective:The randomized controlled trial(ClinicalTrials.gov identifier NCT02990741)will investigate whether more frequent electrocardiographic(ECG)recordings and analyses with an automated ECG system would improve de... Objective:The randomized controlled trial(ClinicalTrials.gov identifier NCT02990741)will investigate whether more frequent electrocardiographic(ECG)recordings and analyses with an automated ECG system would improve detection of atrial fibrillation compared with a single annual ECG screen in elderly Chinese in community health centers.Design:Men and women(≥65 years)will be randomized into intensive(n=3500)and usual(n=3500)screening groups,and within the intensive screening group into intensive screening(n=2625)and more intensive screening(n=875)subgroups.ECG recordings will be performed with an automated ECG analysis system(AliveCor heart monitor)at 1 year in the usual screening group,at 3,6,9,and 12 months in the intensive screening subgroup,and at 1,2,3,and 4 weeks and 3,6,9,and 12 months in the more intensive screening subgroup.The primary outcome is the detection rate of atrial fibrillation between the usual screening group and the intensive screening group.Sample size estimation was based on a projected detection rate of atrial fibrillation of 2.0% by a single ECG recording at 12 months,an improvement of 50% with more frequent ECG recordings,α=0.05,power of 80%,and a one-sided test.Conclusions:The trial will provide evidence on the clinical effectiveness of more frequent ECG recordings by a handheld automated analysis system in the detection of atrial fibrillation. 展开更多
关键词 randomized controlled trial atrial FIBRILLATION SCREENING AUTOMATED electrocardiographic analysis system design
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Design and Analysis of Tapered Stress Joint for Top Tensioned Riser System 被引量:2
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作者 张日曦 张崎 黄一 《China Ocean Engineering》 SCIE EI 2012年第3期507-520,共14页
Stress Joint (SJ) plays a key role in the Top Tensioned Riser (TTR) system for deep water engineering. A preliminary design method of tapered SJ is proposed in the paper, which could help designers obtain accurate... Stress Joint (SJ) plays a key role in the Top Tensioned Riser (TTR) system for deep water engineering. A preliminary design method of tapered SJ is proposed in the paper, which could help designers obtain accurate design data. After a further sensitive analysis is carried out, the related parameters choice and control methods are recommended in the engineering practice. By taking the extreme environment conditions into consideration, the effects of bending stress reduction and curve control are analyzed, and the 3-D FE models are established by ABQOUS for numerical evaluation to verify the correctness of design results. At last, dynamic analysis and fatigue analysis, based on actual project, are carried out with designed stress joint. The analysis results prove the feasibility and guidance of this method in the practical engineering applications. 展开更多
关键词 stress joint (S J) top tensioned riser (TTR) design method parameters sensitivities dynamic analysis fatigue analysis
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