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中国区域卫生规划监督与评价的Logic model(逻辑模型)研究 被引量:9
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作者 雷海潮 张鹭鹭 +2 位作者 马进 龚向光 卞鹰 《中国卫生经济》 北大核心 2002年第10期4-7,共4页
研究的目的是建立中国区域卫生规划的监督与评价体系,推动全国的区域卫生规划工作,采用LogicModel建立了中国区域卫生规划监督与评价的框架和指标体系并对有关实施问题进行了讨论。
关键词 中国 区域卫生规划 logic model 评价指标体系
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Modeling and Control of a Continuous Stirred Tank Reactor Based on a Mixed Logical Dynamical Model 被引量:7
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作者 杜静静 宋春跃 李平 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第4期533-538,共6页
A novel control strategy for a continuous stirred tank reactor(CSTR)system,which has the typical characteristic of strongly pronounced nonlinearity,multiple operating points,and a wide operating range,is initiated fro... A novel control strategy for a continuous stirred tank reactor(CSTR)system,which has the typical characteristic of strongly pronounced nonlinearity,multiple operating points,and a wide operating range,is initiated from the point of hybrid systems.The proposed scheme makes full use of the modeling power of mixed logical dy- namical(MLD)systems to describe the highly nonlinear dynamics and multiple operating points in a unified framework as a hybrid system,and takes advantage of the good control quality of model predictive control(MPC) to design a controller.Thus,this approach avoids oscillation during switching between sub-systems,helps to relieve shaking in transition,and augments the stability robustness of the whole system,and finally achieves optimal(i.e. fast and smooth)transition between operating points.The simulation results demonstrate that the presented ap- proach has a satisfactory performance. 展开更多
关键词 continuous stirred tank reactor mixed logical dynamical model multiple-operating point state transition hybrid system
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Nonlinear inverse modeling of sensor based on back-propagation fuzzy logical system 被引量:2
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作者 李军 刘君华 《Journal of Pharmaceutical Analysis》 SCIE CAS 2007年第1期14-17,共4页
Objective To correct the nonlinear error of sensor output,a new approach to sensor inverse modeling based on Back-Propagation Fuzzy Logical System(BP FS) is presented.Methods The BP FS is a computationally efficient n... Objective To correct the nonlinear error of sensor output,a new approach to sensor inverse modeling based on Back-Propagation Fuzzy Logical System(BP FS) is presented.Methods The BP FS is a computationally efficient nonlinear universal approximator,which is capable of implementing complex nonlinear mapping from its input pattern space to the output with fast convergence speed.Results The neuro-fuzzy hybrid system,i.e.BP FS,is then applied to construct nonlinear inverse model of pressure sensor.The experimental results show that the proposed inverse modeling method automatically compensates the associated nonlinear error in pressure estimation,and thus the performance of pressure sensor is significantly improved.Conclusion The proposed method can be widely used in nonlinearity correction of various kinds of sensors to compensate the effects of nonlinearity and temperature on sensor output. 展开更多
关键词 SENSOR inverse modeling fuzzy logical system back-propagation algorithm
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Model-based and Fuzzy Logic Approaches to Condition Monitoring of Operational Wind Turbines 被引量:3
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作者 Philip Cross Xiandong Ma 《International Journal of Automation and computing》 EI CSCD 2015年第1期25-34,共10页
It is common for wind turbines to be installed in remote locations on land or offshore, leading to difficulties in routine inspection and maintenance. Further, wind turbines in these locations are often subject to har... It is common for wind turbines to be installed in remote locations on land or offshore, leading to difficulties in routine inspection and maintenance. Further, wind turbines in these locations are often subject to harsh operating conditions. These challenges mean there is a requirement for a high degree of maintenance. The data generated by monitoring systems can be used to obtain models of wind turbines operating under different conditions, and hence predict output signals based on known inputs. A model-based condition monitoring system can be implemented by comparing output data obtained from operational turbines with those predicted by the models, so as to detect changes that could be due to the presence of faults. This paper discusses several techniques for model-based condition monitoring systems: linear models, artificial neural networks, and state dependent parameter "pseudo" transfer functions.The models are identified using supervisory control and data acquisition(SCADA) data acquired from an operational wind firm. It is found that the multiple-input single-output state dependent parameter method outperforms both multivariate linear and artificial neural network-based approaches. Subsequently, state dependent parameter models are used to develop adaptive thresholds for critical output signals. In order to provide an early warning of a developing fault, it is necessary to interpret the amount by which the threshold is exceeded, together with the period of time over which this occurs. In this regard, a fuzzy logic-based inference system is proposed and demonstrated to be practically feasible. 展开更多
关键词 Condition monitoring wind turbines artificial neural network state dependent parameter model fuzzy logic
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Intrusion Detection Algorithm Based on Model Checking Interval Temporal Logic 被引量:5
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作者 朱维军 王忠勇 张海宾 《China Communications》 SCIE CSCD 2011年第3期66-72,共7页
Model checking based on linear temporal logic reduces the false negative rate of misuse detection.However,linear temporal logic formulae cannot be used to describe concurrent attacks and piecewise attacks.So there is ... Model checking based on linear temporal logic reduces the false negative rate of misuse detection.However,linear temporal logic formulae cannot be used to describe concurrent attacks and piecewise attacks.So there is still a high rate of false negatives in detecting these complex attack patterns.To solve this problem,we use interval temporal logic formulae to describe concurrent attacks and piecewise attacks.On this basis,we formalize a novel algorithm for intrusion detection based on model checking interval temporal logic.Compared with the method based on model checking linear temporal logic,the new algorithm can find unknown succinct attacks.The simulation results show that the new method can effectively reduce the false negative rate of concurrent attacks and piecewise attacks. 展开更多
关键词 network security intrusion detection misuse detection interval temporal logic model checking
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A study of the logical model of capital market complexity theories
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作者 张大勇 吴冲 +1 位作者 周建 田秋生 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2006年第1期37-42,共6页
Analyzes the shortcomings of the classic capital market theories based on EMH and discloses the complexity essence of the capital market. Considering the capital market a complicated, interactive and adaptable dynamic... Analyzes the shortcomings of the classic capital market theories based on EMH and discloses the complexity essence of the capital market. Considering the capital market a complicated, interactive and adaptable dynamic system, with complexity science as the method for researching the operation law of the capital market, this paper constructs a nonlinear logical model to analyze the applied realm, focal point and interrelationship of such theories as dissipative structure theory, chaos theory, fractal theory, synergetics theory, catastrophe theory and scale theory, and summarizes and discusses the achievements and problems of each theory. Based on the research, the paper foretells the developing direction of eomplexity science in a capital market. 展开更多
关键词 capital market logical model COMPLEXITY FRACTAL CHAOS scale theory
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Three-dimensional fuzzy logic system for process modeling and control 被引量:2
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作者 Han-Xiong LI Xiaogang DUAN Zhi LIU 《控制理论与应用(英文版)》 EI 2010年第3期280-285,共6页
The traditional fuzzy logic system (FLS) can only model and control the process in two-dimensional nature. Many of real-world systems are of multidimensional features, such as, thermal and fluid processes with spati... The traditional fuzzy logic system (FLS) can only model and control the process in two-dimensional nature. Many of real-world systems are of multidimensional features, such as, thermal and fluid processes with spatiotemporal dynamics, biological systems, or decision-making processes that contain stochastic and imprecise uncertainties. These types of systems are difficult for the traditional FLS to model and control because they require a third dimension for spatial or probabilistic information. The type-2 fuzzy set provides the possibility to develop a three-dimensional fuzzy logic system for modeling and controlling these processes in three-dimensional nature. 展开更多
关键词 Three-dimensional fuzzy logic system Spatiotemporal system modelING
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Fault detection and identification based on combining logic and model in a wall-climbing robot
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作者 Yong JIANG Hongguang WANG +1 位作者 Lijin FANG Mingyang ZHAO 《控制理论与应用(英文版)》 EI 2009年第2期157-162,共6页
A combined logic- and model-based approach to fault detection and identification (FDI) in a suction foot control system of a wall-climbing robot is presented in this paper. For the control system, some fault models ... A combined logic- and model-based approach to fault detection and identification (FDI) in a suction foot control system of a wall-climbing robot is presented in this paper. For the control system, some fault models are derived by kinematics analysis. Moreover, the logic relations of the system states are known in advance. First, a fault tree is used to analyze the system by evaluating the basic events (elementary causes), which can lead to a root event (a particular fault). Then, a multiple-model adaptive estimation algorithm is used to detect and identify the model-known faults. Finally, based on the system states of the robot and the results of the estimation, the model-unknown faults are also identified using logical reasoning. Experiments show that the proposed approach based on the combination of logical reasoning and model estimating is efficient in the FDI of the robot. 展开更多
关键词 FDI Fault tree model estimation logic reasoning Wall-climbing robot
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Research on Mixed Logic Dynamic Modeling and Finite Control Set Model Predictive Control of Multi-Inverter Parallel System
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作者 Xiaojuan Lu Mengqiao Chen Qingbo Zhang 《Energy Engineering》 EI 2023年第3期649-664,共16页
Parallel connection of multiple inverters is an important means to solve the expansion,reserve and protection of distributed power generation,such as photovoltaics.In view of the shortcomings of traditional droop cont... Parallel connection of multiple inverters is an important means to solve the expansion,reserve and protection of distributed power generation,such as photovoltaics.In view of the shortcomings of traditional droop control methods such as weak anti-interference ability,low tracking accuracy of inverter output voltage and serious circulation phenomenon,a finite control set model predictive control(FCS-MPC)strategy of microgrid multiinverter parallel system based on Mixed Logical Dynamical(MLD)modeling is proposed.Firstly,the MLD modeling method is introduced logical variables,combining discrete events and continuous events to form an overall differential equation,which makes the modeling more accurate.Then a predictive controller is designed based on the model,and constraints are added to the objective function,which can not only solve the real-time changes of the control system by online optimization,but also effectively obtain a higher tracking accuracy of the inverter output voltage and lower total harmonic distortion rate(Total Harmonics Distortion,THD);and suppress the circulating current between the inverters,to obtain a good dynamic response.Finally,the simulation is carried out onMATLAB/Simulink to verify the correctness of the model and the rationality of the proposed strategy.This paper aims to provide guidance for the design and optimal control of multi-inverter parallel systems. 展开更多
关键词 Multiple inverters in parallel microgrid mixed logic dynamic model finite control set model predictive control circulation
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Physics-based analysis and simulation model of electromagnetic interference induced soft logic upset in CMOS inverter 被引量:4
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作者 Yu-Qian Liu Chang-Chun Chai +4 位作者 Yu-Hang Zhang Chun-Lei Shi Yang Liu Qing-Yang Fan Yin-Tang Yang 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第6期531-538,共8页
The instantaneous reversible soft logic upset induced by the electromagnetic interference(EMI) severely affects the performances and reliabilities of complementary metal–oxide–semiconductor(CMOS) inverters. This... The instantaneous reversible soft logic upset induced by the electromagnetic interference(EMI) severely affects the performances and reliabilities of complementary metal–oxide–semiconductor(CMOS) inverters. This kind of soft logic upset is investigated in theory and simulation. Physics-based analysis is performed, and the result shows that the upset is caused by the non-equilibrium carrier accumulation in channels, which can ultimately lead to an abnormal turn-on of specific metal–oxide–semiconductor field-effect transistor(MOSFET) in CMOS inverter. Then a soft logic upset simulation model is introduced. Using this model, analysis of upset characteristic reveals an increasing susceptibility under higher injection powers, which accords well with experimental results, and the influences of EMI frequency and device size are studied respectively using the same model. The research indicates that in a range from L waveband to C waveband, lower interference frequency and smaller device size are more likely to be affected by the soft logic upset. 展开更多
关键词 electromagnetic interference soft logic upset non-equilibrium carrier upset model
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A Probabilistic Paraconsistent Logical Model for Non-Relativistic Quantum Mechanics Using Interlaced Bilattices with Conflation and Bernoulli Distribution
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作者 Joao Inacio Da Silva Filho 《Journal of Quantum Information Science》 2017年第3期89-124,共36页
In this work, we make a representation of non-relativistic quantum theory based on foundations of paraconsistent annotated logic (PAL), a propositional and evidential logic with an associated lattice FOUR. We use the ... In this work, we make a representation of non-relativistic quantum theory based on foundations of paraconsistent annotated logic (PAL), a propositional and evidential logic with an associated lattice FOUR. We use the PAL version with annotation of two values (PAL2v), named paraquantum logic (PQL), where the evidence signals are normalized values and the intensities of the inconsistencies are represented by degrees of contradiction. Quantum mechanics is represented through mapping on the interlaced bilattices where this logical formalization allows annotation of two values in the format of degrees of evidence of probability. The Bernoulli probability distribution is used to establish probabilistic logical states that identify the superposition of states and quantum entanglement with the equations and determine the state vectors located inside the interlaced Bilattice. In the proposed logical probabilistic paraquantum logic model (pPQL Model), we introduce the operation of logical conflation into interlaced bilattice. We verify that in the pPQL Model, the operation of logical conflation is responsible for providing a suitable model for various phenomena of quantum mechanics, mainly the quantum entanglement. The results obtained from the entanglement equations demonstrate the formalization and completeness of paraquantum logic that allows for interpretations of similar phenomena of quantum mechanics, including EPR paradox and the wave-particle theory. 展开更多
关键词 Paraconsistent logic Interlaced Bilattice Probability Theory Quantum Mechanics Paraquantum logic model
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A Fuzzy Logic Model to Predict the Bioleaching Efficiency of Copper Concentrates in Stirred Tank Reactors
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作者 Ali Ahmadi Mohammad Raouf Hosseini 《International Journal of Nonferrous Metallurgy》 2015年第1期1-8,共8页
Multiplicity of the chemical, biological, electrochemical and operational variables and nonlinear behavior of metal extraction in bioleaching environments complicate the mathematical modeling of these systems. This re... Multiplicity of the chemical, biological, electrochemical and operational variables and nonlinear behavior of metal extraction in bioleaching environments complicate the mathematical modeling of these systems. This research was done to predict copper and iron recovery from a copper flotation concentrate in a stirred tank bioreactor using a fuzzy logic model. Experiments were carried out in the presence of a mixed culture of mesophilic bacteria at 35° C, and a mixed culture of moderately thermophilic bacteria at 50° C. Input variables were method of operation (bioleaching or electrobioleaching), the type of bacteria and time (day), while the recoveries of copper and iron were the outputs. A relationship was developed between stated inputs and the outputs by means of “if-then” rules. The resulting fuzzy model showed a satisfactory prediction of the copper and iron extraction and had a good correlation of experimental data with R-squared more than 0.97. The results of this study suggested that fuzzy logic provided a powerful and reliable tool for predicting the nonlinear and time variant bioleaching processes. 展开更多
关键词 FUZZY logic modeling Copper CONCENTRATE BIOLEACHING Stirred REACTOR
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A Logical Growth Model considering the influence of shale gas reservoirs and development characteristics
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作者 Zhao Qun Wang Hongyan +4 位作者 Sun Qinping Jiang Xinchun Yu Rongze Kang Lixia Wang Xuefan 《Natural Gas Industry B》 2020年第6期656-663,共8页
As shale gas development is advancing continuously and rapidly,how to deeply analyze the production performance of shale gas wells and evaluate their production characteristics has become an urgent problem in the eval... As shale gas development is advancing continuously and rapidly,how to deeply analyze the production performance of shale gas wells and evaluate their production characteristics has become an urgent problem in the evaluation of shale gas productivity construction zone,the formulation of new area development scheme and the preparation of planning program.Some scholars have applied the Logical Growth Model(LGM)in the production decline analysis of unconventional gas wells,but the influences of shale gas reservoir and development characteristics are not taken into consideration.Therefore,this method still has some space of further development and improvement.In this paper,a Logistic Growth Model considering shale gas reservoirs and development characteristics(RB-LGM)was established based on the previous research results.Then,it was applied to the shale gas development wells in the Changning Block of the Sichuan Basin to analyze their production performance,and the analysis results were compared with thefitting and prediction results provided by the Arps hyperbolic decline model.Finally,the optimal well spacing of horizontal wells was determined using RB-LGM.And the following research results were obtained.First,shale gas is produced by deploying horizontal wells in the clustered pattern in a large number,so on the basis of LGM,RB-LGM takes shale gas reservoir parameters(thickness,shale density,gas content)and development parameters(horizontal section length,well spacing and recovery factor)as the logic control factors of horizontal-well gas productionfitting,so that the production prediction result of gas well is more reasonable.Second,RB-LGM can not only wellfit the early production data of gas well,but ensure the convergence of the later prediction results under the control of logical conditions.Third,RB-LGM takes into account the influence of shale gas reservoir and development characteristics so as to optimize the horizontal well pattern and analyze the change trend of reservoir parameters in the development area through data inversion. 展开更多
关键词 Shale gas Reservoir characteristics Production decline logical Growth model Horizontal well Arps decline model Well spacing optimization Economic benefit Changning Block of the Sichuan Basin
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Undulatory Theory with Paraconsistent Logic (Part I): Quantum Logical Model with Two Wave Functions 被引量:1
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作者 João Inácio Da Silva Filho 《Journal of Quantum Information Science》 2016年第3期143-180,共38页
Paraconsistent logic (PL) is a non-classical logic that accepts contradiction in its foundations. It can be represented in the form of paraconsistent annotated logic with annotation of two values (PAL2v). When used to... Paraconsistent logic (PL) is a non-classical logic that accepts contradiction in its foundations. It can be represented in the form of paraconsistent annotated logic with annotation of two values (PAL2v). When used to model quantum phenomena, PAL2v is called paraquantum logic (PQL). In this work, the concept of PQL is applied to create a logical model presenting the fundamental principles of quantum mechanics that support particle-wave theory. This study uses the well-known Young’s double-slit experiment, wherein quantum phenomena appear when a monochromatic light beam passes through the two slits. We focused on a reference point located between the slits, where we observed the effects of two types of wave interferences in a region defined as a two-wave region (2W region). Considering that the effect in this 2W region is very similar to that studied by Huygens, we adopt a paraquantum logical model in which a particle (or quantum) is represented by two wave functions. The two wave functions result in four State Vectors (Ket, Bra,,) in the PQL Lattice that express the symmetry and the entanglement of Quantum Mechanics. The constructed model adapts well to the quantum phenomena, is strongly consistent, and can be considered as an innovative form of analysis in the field of quantum mechanics. Based on this model, we present in two parts (Part I and Part II) the comparative analysis of values found in Schr&#214;dinger’s equation and probabilistic models of wave-particle theory using Bonferroni inequality. 展开更多
关键词 Paraconsistent logic Quantum Mechanics Paraquantum logic Undulatory Theory Quantum model
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Logic Picture-Based Dynamic Power Estimation for Unit Gate-Delay Model CMOS Circuits
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作者 Omnia S. Ahmed Mohamed F. Abu-Elyazeed +2 位作者 Mohamed B. Abdelhalim Hassanein H. Amer Ahmed H. Madian 《Circuits and Systems》 2013年第3期276-279,共4页
In this research, a fast methodology to calculate the exact value of the average dynamic power consumption for CMOS combinational logic circuits is developed. The delay model used is the unit-delay model where all gat... In this research, a fast methodology to calculate the exact value of the average dynamic power consumption for CMOS combinational logic circuits is developed. The delay model used is the unit-delay model where all gates have the same propagation delay. The main advantages of this method over other techniques are its accuracy, as it is deterministic and it requires less computational effort compared to exhaustive simulation approaches. The methodology uses the Logic Pictures concept for obtaining the nodes’ toggle rates. The proposed method is applied to well-known circuits and the results are compared to exhaustive simulation and Monte Carlosimulation methods. 展开更多
关键词 Dynamic Power ESTIMATION logic PICTURES CMOS Digital logic Circuits TOGGLE Rate Unit-Delay model
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基于Logic回归模型的农民宅基地退出意愿测算——以玉泉镇4个村庄为例 被引量:13
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作者 魏晨 陈英 +1 位作者 白志远 黄思琴 《中国农学通报》 CSCD 2014年第32期114-121,共8页
采用问卷调查法与Logic回归分析法,以玉泉镇4个村庄为例,分析影响农民宅基地退出意愿因素,目的在于了解农民的态度和想法,从而有针对性开展相关工作以激发农民退出意愿,保障农村宅基地稳定退出。Logic回归分析的结果表明,农民宅基地退... 采用问卷调查法与Logic回归分析法,以玉泉镇4个村庄为例,分析影响农民宅基地退出意愿因素,目的在于了解农民的态度和想法,从而有针对性开展相关工作以激发农民退出意愿,保障农村宅基地稳定退出。Logic回归分析的结果表明,农民宅基地退出意愿与农民拥有职业技能、家庭中外出打工人数、家庭年收入、家庭中宅基地数量有显著正向关系,与农民年龄、农业收入比重、(每户)宅基地总面积有显著负向关系。根据Logic回归分析得出的结论,提出几点政策建议激发农民退出意愿:提高退出补偿标准、开展农民职业技能培训、增加农民收入等。 展开更多
关键词 宅基地 农民退出意愿 影响因素 logic回归分析
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院地合作驱动肿瘤专科医院科技创新能力提升路径研究:基于13家医院的fsQCA分析与浙江省肿瘤医院实践
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作者 娄懿 潘柯蓉 +3 位作者 徐哲伟 高颜超 陈蕾 裘燕飞 《中国肿瘤》 北大核心 2026年第1期63-68,共6页
[目的]分析肿瘤专科医院科技创新能力提升的核心要素,并以浙江省肿瘤医院院所融合模式为例,探索院地合作模式下肿瘤专科医院发展的多元路径。[方法]选取全国13家知名三甲肿瘤专科医院为样本,收集各单位2023年中国医院科技量值(Science a... [目的]分析肿瘤专科医院科技创新能力提升的核心要素,并以浙江省肿瘤医院院所融合模式为例,探索院地合作模式下肿瘤专科医院发展的多元路径。[方法]选取全国13家知名三甲肿瘤专科医院为样本,收集各单位2023年中国医院科技量值(Science and Technology Evaluation Metrics,STEM)填报数据,采用模糊集定性比较分析法(fuzzy-set qualitative compar-ative analysis,fsQCA),解析影响创新活力的多维并发因素及科技创新能力提升的组态路径。[结果]单一因素必要性分析显示,所选5个条件变量(国家级科研平台、国家自然科学基金等)均不构成高水平/非高水平科技创新能力(technological innovation capacity,TIC)的必要条件(一致性均<0.9);通过fsQCA识别出6条组态路径,其中4条为高水平TIC路径、2条为非高水平TIC路径,且组态1(非高国家级科研平台+高两院院士存量)与浙江省肿瘤医院院所融合后的创新特征高度契合,印证顶尖人才对弥补平台短板的关键作用。稳健性检验[调整一致性阈值至0.9、不一致性的比例减少(proportional reduction in inconsistency,PRI)一致性阈值至0.7]显示结果可靠。[结论]院所融合模式可短期内显著提升肿瘤专科医院科技创新能力,浙江省肿瘤医院的实践为缺乏高能级科研平台的同类医院提供了“人才驱动”的有效路径,但该院在顶级成果产出、重大平台建设等长期核心要素上仍有提升空间;基于13家医院的组态规律与该院实践,提出资源共享深度化、人才流动制度化等针对性举措,为院地合作医院的创新能力持续提升提供支撑。 展开更多
关键词 院所融合 肿瘤专科医院 科技创新模式 模糊集定性比较分析法 路径
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教育家精神融入师范教育课程:内在逻辑、课程样态及实现
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作者 肖海平 王洪兰 《湖北工程学院学报》 2026年第1期59-64,共6页
教育家精神融入师范教育课程是新时代教师队伍建设的核心议题,其有效落实需遵循“价值认同-实践体认-文化浸润”的内在逻辑。价值逻辑着眼于从认知共鸣到信念内化的生成过程;实践逻辑强调精神在反思性行动中的具身体认与创生;文化逻辑... 教育家精神融入师范教育课程是新时代教师队伍建设的核心议题,其有效落实需遵循“价值认同-实践体认-文化浸润”的内在逻辑。价值逻辑着眼于从认知共鸣到信念内化的生成过程;实践逻辑强调精神在反思性行动中的具身体认与创生;文化逻辑则立足于专业学习共同体的浸润涵养作用。在此基础上构建的“浸润-反思-协同”课程样态,通过浸润式模块课程、反思性实践课程与协同化社群课程的有机整合,形成三位一体的育人结构。为确保课程样态的实施,需要建立包括专业化教师队伍、发展性评价机制和协同化资源保障在内的支持体系,共同构成教育家精神融入师范教育课程的系统性框架。 展开更多
关键词 教育家精神 师范教育课程 内在逻辑 课程样态 实现条件
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A Hybrid Approach to Modeling and Control of Vehicle Height for Electronically Controlled Air Suspension 被引量:8
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作者 SUN Xiaoqiang CAI Yingfeng +2 位作者 WANG Shaohua LIU Yanling CHEN Long 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第1期152-162,共11页
The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on t... The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties. 展开更多
关键词 electronically controlled air suspension vehicle height control hybrid system mixed logical dynamical model predictive control
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Probabilistic seismic hazard assessment of Nepal using multiple seismic source models 被引量:2
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作者 Md Moklesur Rahman Ling Bai 《Earth and Planetary Physics》 2018年第4期327-341,共15页
The potential for devastating earthquakes in the Himalayan orogeny has long been recognized. The 2015 MW7.8 Gorkha, Nepal earthquake has heightened the likelihood that major earthquakes will occur along this orogenic ... The potential for devastating earthquakes in the Himalayan orogeny has long been recognized. The 2015 MW7.8 Gorkha, Nepal earthquake has heightened the likelihood that major earthquakes will occur along this orogenic belt in the future. Reliable seismic hazard assessment is a critical element in development of policy for seismic hazard mitigation and risk reduction. In this study, we conduct probabilistic seismic hazard assessment using three different seismogenic source models(smoothed gridded, linear, and areal sources)based on the complicated tectonics of the study area. Two sets of ground motion prediction equations are combined in a standard logic tree by taking into account the epistemic uncertainties in hazard estimation. Long-term slip rates and paleoseismic records are also incorporated in the linear source model. Peak ground acceleration and spectral acceleration at 0.2 s and 1.0 s for 2% and 10%probabilities of exceedance in 50 years are estimated. The resulting maps show significant spatial variation in seismic hazard levels. The region of the Lesser Himalaya is found to have high seismic hazard potential. Along the Main Himalayan Thrust from east to west beneath the Main Central Thrust, large earthquakes have occurred regularly in history; hazard values in this region are found to be higher than those shown on existing hazard maps. In essence, the combination of long span earthquake catalogs and multiple seismogenic source models gives improved seismic hazard constraints in Nepal. 展开更多
关键词 Gorkha EARTHQUAKE probabilistic SEISMIC HAZARD PEAK ground ACCELERATION spectral ACCELERATION source models logic tree
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