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A cloud model target damage effectiveness assessment algorithm based on spatio-temporal sequence finite multilayer fragments dispersion
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作者 Hanshan Li Xiaoqian Zhang Junchai Gao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期48-64,共17页
To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept,this paper proposes a method for calculating target damage p... To solve the problem of target damage assessment when fragments attack target under uncertain projectile and target intersection in an air defense intercept,this paper proposes a method for calculating target damage probability leveraging spatio-temporal finite multilayer fragments distribution and the target damage assessment algorithm based on cloud model theory.Drawing on the spatial dispersion characteristics of fragments of projectile proximity explosion,we divide into a finite number of fragments distribution planes based on the time series in space,set up a fragment layer dispersion model grounded in the time series and intersection criterion for determining the effective penetration of each layer of fragments into the target.Building on the precondition that the multilayer fragments of the time series effectively assail the target,we also establish the damage criterion of the perforation and penetration damage and deduce the damage probability calculation model.Taking the damage probability of the fragment layer in the spatio-temporal sequence to the target as the input state variable,we introduce cloud model theory to research the target damage assessment method.Combining the equivalent simulation experiment,the scientific and rational nature of the proposed method were validated through quantitative calculations and comparative analysis. 展开更多
关键词 Target damage Cloud model Fragments dispersion effectiveness assessment Spatio-temporal sequence
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Phosphorus limitation on CO_(2)fertilization effect in tropical forests informed by a coupled biogeochemical model
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作者 Zhuonan Wang Hanqin Tian +5 位作者 Shufen Pan Hao Shi Jia Yang Naishen Liang Latif Kalin Christopher Anderson 《Forest Ecosystems》 SCIE CSCD 2024年第4期502-515,共14页
Tropical forests store more than half of the world's terrestrial carbon(C)pool and account for one-third of global net primary productivity(NPP).Many terrestrial biosphere models(TBMs)estimate increased productivi... Tropical forests store more than half of the world's terrestrial carbon(C)pool and account for one-third of global net primary productivity(NPP).Many terrestrial biosphere models(TBMs)estimate increased productivity in tropical forests throughout the 21st century due to CO_(2)fertilization.However,phosphorus(P)liaitations on vegetation photosynthesis and productivity could significantly reduce the CO_(2)fertilization effect.Here,we used a carbon-nitrogen-phosphorus coupled model(Dynamic Land Ecosystem Model;DLEM-CNP)with heterogeneous maximum carboxylation rates to examine how P limitation has affected C fluxes in tropical forests during1860-2018.Our model results showed that the inclusion of the P processes enhanced model performance in simulating ecosystem productivity.We further compared the simulations from DLEM-CNP,DLEM-CN,and DLEMC and the results showed that the inclusion of P processes reduced the CO_(2)fertilization effect on gross primary production(GPP)by 25%and 45%,and net ecosystem production(NEP)by 28%and 41%,respectively,relative to CN-only and C-on ly models.From the 1860s to the 2010s,the DLEM-CNP estimated that in tropical forests GPP increased by 17%,plant respiration(Ra)increased by 18%,ecosystem respiration(Rh)increased by 13%,NEP increased by 121%per unit area,respectively.Additionally,factorial experiments with DLEM-CNP showed that the enhanced NPP benefiting from the CO_(2) fertilization effect had been offset by 135%due to deforestation from the 1860s to the 2010s.Our study highlights the importance of P limitation on the C cycle and the weakened CO_(2)fertilization effect resulting from P limitation in tropical forests. 展开更多
关键词 Tropical forests Carbon-nitrogen-phosphorus model Phosphorus limitation CO_(2)fertilization effect Terrestfial ecosy stem model
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Contribution of the MERISE-Type Conceptual Data Model to the Construction of Monitoring and Evaluation Indicators of the Effectiveness of Training in Relation to the Needs of the Labor Market in the Republic of Congo
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作者 Roch Corneille Ngoubou Basile Guy Richard Bossoto Régis Babindamana 《Open Journal of Applied Sciences》 2024年第8期2187-2200,共14页
This study proposes the use of the MERISE conceptual data model to create indicators for monitoring and evaluating the effectiveness of vocational training in the Republic of Congo. The importance of MERISE for struct... This study proposes the use of the MERISE conceptual data model to create indicators for monitoring and evaluating the effectiveness of vocational training in the Republic of Congo. The importance of MERISE for structuring and analyzing data is underlined, as it enables the measurement of the adequacy between training and the needs of the labor market. The innovation of the study lies in the adaptation of the MERISE model to the local context, the development of innovative indicators, and the integration of a participatory approach including all relevant stakeholders. Contextual adaptation and local innovation: The study suggests adapting MERISE to the specific context of the Republic of Congo, considering the local particularities of the labor market. Development of innovative indicators and new measurement tools: It proposes creating indicators to assess skills matching and employer satisfaction, which are crucial for evaluating the effectiveness of vocational training. Participatory approach and inclusion of stakeholders: The study emphasizes actively involving training centers, employers, and recruitment agencies in the evaluation process. This participatory approach ensures that the perspectives of all stakeholders are considered, leading to more relevant and practical outcomes. Using the MERISE model allows for: • Rigorous data structuring, organization, and standardization: Clearly defining entities and relationships facilitates data organization and standardization, crucial for effective data analysis. • Facilitation of monitoring, analysis, and relevant indicators: Developing both quantitative and qualitative indicators helps measure the effectiveness of training in relation to the labor market, allowing for a comprehensive evaluation. • Improved communication and common language: By providing a common language for different stakeholders, MERISE enhances communication and collaboration, ensuring that all parties have a shared understanding. The study’s approach and contribution to existing research lie in: • Structured theoretical and practical framework and holistic approach: The study offers a structured framework for data collection and analysis, covering both quantitative and qualitative aspects, thus providing a comprehensive view of the training system. • Reproducible methodology and international comparison: The proposed methodology can be replicated in other contexts, facilitating international comparison and the adoption of best practices. • Extension of knowledge and new perspective: By integrating a participatory approach and developing indicators adapted to local needs, the study extends existing research and offers new perspectives on vocational training evaluation. 展开更多
关键词 MERISE Conceptual Data model (MCD) Monitoring Indicators Evaluation of Training effectiveness Training-employment Adequacy Labor Market Information Systems Analysis Adjustment of Training Programs emPLOYABILITY Professional Skills
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UML-based combat effectiveness simulation system modeling within MDE 被引量:5
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作者 ZHU Zhi LEI Yonglin +2 位作者 SARJOUGHIAN Hessam LI Xiaobo ZHU Yifan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第6期1180-1196,共17页
To reduce complexity, the combat effectiveness simulation system(CESS) is often decomposed into static structure,physical behavior, and cognitive behavior, and model abstraction is layered onto domain invariant knowle... To reduce complexity, the combat effectiveness simulation system(CESS) is often decomposed into static structure,physical behavior, and cognitive behavior, and model abstraction is layered onto domain invariant knowledge(DIK) and application variant knowledge(AVK) levels. This study concentrates on the specification of CESS’s physical behaviors at the DIK level of abstraction, and proposes a model driven framework for efficiently developing simulation models within model-driven engineering(MDE). Technically, this framework integrates the four-layer metamodeling architecture and a set of model transformation techniques with the objective of reducing model heterogeneity and enhancing model continuity. As a proof of concept, a torpedo example is illustrated to explain how physical models are developed following the proposed framework. Finally, a combat scenario is constructed to demonstrate the availability, and a further verification is shown by a reasonable agreement between simulation results and field observations. 展开更多
关键词 domain specific modeling model-driven development system engineering effectiveness simulation
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Model architecture-oriented combat system effectiveness simulation based on MDE 被引量:3
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作者 Yonglin Lei Ning Zhu +2 位作者 Jian Yao Hessam Sarjoughian Weiping Wang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2017年第5期900-922,共23页
Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are g... Combat system effectiveness simulation (CSES) is a special type of complex system simulation. Three non-functional requirements (NFRs), i.e. model composability, domain specific modeling, and model evolvability, are gaining higher priority from CSES users when evaluating different modeling methodologies for CSES. Traditional CSES modeling methodologies are either domain-neutral (lack of domain characteristics consideration and limited support for model composability) or domain-oriented (lack of openness and evolvability) and fall short of the three NFRs. Inspired by the concept of architecture in systems engineering and software engineering fields, we extend it into a concept of model architecture for complex simulation systems, and propose a model architecture-oriented modeling methodology in which the model architecture plays a central role in achieving the three NFRs. Various model-driven engineering (MDE) approaches and technologies, including simulation modeling platform (SMP), unified modeling language (UML), domain specific modeling (DSM), eclipse modeling framework (EMF), graphical modeling framework (GMF), and so forth, are applied where possible in representing the CSES model architecture and its components' behaviors from physical and cognitive domain aspects. A prototype CSES system, called weapon effectiveness simulation system (WESS), and a non-trivial air-combat simulation example are presented to demonstrate the methodology. 展开更多
关键词 combat system effectiveness simulation (CSES) model architecture model-driven engineering (MDE) simulation modeling platform (SMP) domain specific modeling (DSM) weapon effectiveness simulation system (WESS)
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ADC-GERT network parameter estimation model for mission effectiveness of joint operation system 被引量:4
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作者 FANG Zhigeng WU Shuang +1 位作者 ZHANG Xiaoli SUN Yunke 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第6期1394-1406,共13页
Effectiveness evaluation of the joint operation system is an important basis for the demonstration and development of weapon equipment.With the consideration that existing models of system effectiveness evaluation sel... Effectiveness evaluation of the joint operation system is an important basis for the demonstration and development of weapon equipment.With the consideration that existing models of system effectiveness evaluation seldom describe the structural relationship among equipment clearly as well as reflect the dynamic,the analog-to-digital converter-graphical evaluation and review technique(ADC-GERT)network parameter estimation model is proposed based on the ADC model and the joint operation system structure.Firstly,analysis of the joint operation system structure and operation process is conducted to build the GERT network,where equipment subsystems are nodes and activities are directed arches.Then the mission effectiveness of equipment subsystems is calculated by the ADC model.The probability transfer parameters are modified by the mission effectiveness of equipment subsystems based on the Bayesian theorem,with the ADC-GERT network parameter estimation model constructed.Finally,a case study is used to validate the efficiency and dynamic of the ADC-GERT network parameter estimation model. 展开更多
关键词 joint operation system system mission effectiveness analog-to-digital converter(ADC)model graphical evaluation and review technique(GERT) parameter estimation
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Role of methoxy and C_(α)-based substituents in electrochemical oxidation mechanisms and bond cleavage selectivity of β-O-4 lignin model compounds 被引量:1
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作者 Yang Zhou Qiang Zeng +3 位作者 Hongyan He Kejia Wu Fuqiao Liu Xuehui Li 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第1期114-125,共12页
In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl gro... In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations. 展开更多
关键词 Lignin model compounds β-O-4 dimers Electrochemical oxidation Oxidation mechanisms Substituent effect
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Experimental, Numerical and Simplified Theoretical Model Study for Internal Solitary Wave Load on FPSO with Emphasis on Scale Effect 被引量:8
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作者 ZHANG Rui-rui CHEN Ke YOU Yun-xiang 《China Ocean Engineering》 SCIE EI CSCD 2019年第1期26-33,共8页
Scale effect of ISWs loads on Floating Production Storage and Offloading(FPSO) is studied in this paper. The application conditions of KdV, eKdV and MCC ISWs theories are used in the numerical method. The depthaverage... Scale effect of ISWs loads on Floating Production Storage and Offloading(FPSO) is studied in this paper. The application conditions of KdV, eKdV and MCC ISWs theories are used in the numerical method. The depthaveraged velocities induced by ISWs are used for the velocity-inlet boundary. Three scale ratio numerical models λ=1, 20 and 300 were selected, which the scale ratio is the size ratio of numerical models to the experimental model.The comparisons between the numerical and former experimental results are performed to verify the feasibility of numerical method. The comparisons between the numerical and simplified theoretical results are performed to discuss the applicability of the simplified theoretical model summarized from the load experiments. Firstly, the numerical results of λ=1 numerical model showed a good agreement with former experimental and simplified theoretical results. It is feasible to simulate the ISWs loads on FPSO by the numerical method. Secondly, the comparisons between the results of three scale ratio numerical models and experimental results indicated that the scale ratios have more significant influence on the experimental horizontal forces than the vertical forces. The scale effect of horizontal forces mainly results from the different viscosity effects associated with the model’s dimension.Finally, through the comparisons between the numerical and simplified theoretical results for three scale ratio models, the simplified theoretical model of the pressure difference and friction forces exerted by ISWs on FPSO is applied for large-scale or full-scale FPSO. 展开更多
关键词 scale effect FPSO INTERNAL SOLITARY wave NUMERICAL simulation simplified THEORETICAL model
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Cardiovascular Cast Model Fabrication and Casting Effectiveness Evaluation in Fetus with Severe Congenital Heart Disease or Normal Heart 被引量:10
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作者 王瑜 曹海燕 +9 位作者 谢明星 贺林 韩伟 洪柳 彭源 胡云飞 宋本才 王静 王斌 邓诚 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2016年第2期259-264,共6页
To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease(control group) and 18 spe... To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease(control group) and 18 specimens with severe congenital heart disease(case group) from induced abortions were enrolled in this study from March 2013 to June 2015 in our hospital. Cast models were prepared by injecting casting material into vascular lumen to demonstrate real geometries of fetal cardiovascular system. Casting effectiveness was analyzed in terms of local anatomic structures and different anatomical levels(including overall level, atrioventricular and great vascular system, left-sided and right-sided heart), as well as different trimesters of pregnancy. In our study, all specimens were successfully casted. Casting effectiveness analysis of local anatomic structures showed a mean score from 1.90±1.45 to 3.60±0.52, without significant differences between case and control groups in most local anatomic structures except left ventricle, which had a higher score in control group(P=0.027). Inter-group comparison of casting effectiveness in different anatomical levels showed no significant differences between the two groups. Intra-group comparison also revealed undifferentiated casting effectiveness between atrioventricular and great vascular system, or left-sided and right-sided heart in corresponding group. Third-trimester group had a significantly higher perfusion score in great vascular system than second-trimester group(P=0.046), while the other anatomical levels displayed no such difference. Vascular corrosion technique can be successfully used in fabrication of fetal cardiovascular cast model. It is also a reliable method to demonstrate three-dimensional anatomy of severe congenital heart disease and normal heart in fetus. 展开更多
关键词 severe congenital heart disease FETUS cast model anatomy casting effectiveness PERFUSION
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A framework for equipment systems-of-systems effectiveness evaluation using parallel experiments approach 被引量:7
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作者 Zilong Cheng Li Fan Yulin Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第2期292-300,共9页
Equipment systems-of-systems (SOS) effectiveness evaluation can provide important reference for construction and optimization of the equipment SoS. After discussing the basic theory and methods of parallel experimen... Equipment systems-of-systems (SOS) effectiveness evaluation can provide important reference for construction and optimization of the equipment SoS. After discussing the basic theory and methods of parallel experiments, we depict an SoS effectiveness analysis and evaluation method using parallel expe- riments theory in detail. A case study is carried out which takes the missile defense system as an example. An artificial system of the missile defense system is constructed with the multi-agent modeling method. Then, single factor, multiple factors and defense position deployment computational experiments are carried out and evaluated with the statistical analysis method. Experiment re- sults show that the altitude of the secondary interception missile is not the key factor which affects SoS effectiveness and putting the defense position ahead will increase defense effectiveness. The case study demonstrates the feasibility of the proposed method. 展开更多
关键词 agent based modeling parallel experiments computational experiments missile defense system effectiveness evaluation
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Modelling seedling development using thermal effectiveness and photosynthetically active radiation 被引量:5
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作者 ZHOU Tian-mei WU Zhen +4 位作者 WANG Ya-chen SU Xiao-jun QIN Chao-xuan HUO He-qiang JIANG Fang-ling 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第11期2521-2533,共13页
Seedling quality is a prerequisite for successful field performance and therefore influences crop yields. Temperature and illumination are two major factors affecting seedling quality during nursery propagation. Subop... Seedling quality is a prerequisite for successful field performance and therefore influences crop yields. Temperature and illumination are two major factors affecting seedling quality during nursery propagation. Suboptimal temperature or light of nurseries generally result in leggy or weak seedlings and great economic loss. However, production of healthy seedlings is challenging due to the lack of knowledge in systemic management of nursery environments. In this study, we have established simulation models to predict how temperature and illumination coordinately influence the growth of tomato and cabbage seedlings. Specifically, correlation between seedling quality characteristics(root-shoot ratio, G value(growth function: defined as ratio of whole plant dry weight to days of seedling), healthy indexes) and TEP(thermal effectiveness and photosynthetically active radiation) were explored to establish the models, which were validated with independent test data. Our results suggested that the curve of healthy index 1(HI1) and TEP fitted well with high coefficient of determination(R2) in both species, indicating that the model is highly reliable. The HI1 simulation models for tomato and cabbage are HI1=0.0009e0.0308TEP-0.0015 and HI1= 0.0003e0.0671TEP-0.0003, respectively, which can be used for predicting vigors of tomato and cabbage seedlings grown under different temperature and light conditions. 展开更多
关键词 TOMATO CABBAGE simulation model thermal effectiveness and photosynthetically active radiation HEALTHY index G VALUE
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A macroscopic multi-mechanism based constitutive model for the thermo-mechanical cyclic degeneration of shape memory effect of NiTi shape memory alloy 被引量:6
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作者 Chao Yu Guozheng Kang Qianhua Kan 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2017年第3期619-634,共16页
A macroscopic based multi-mechanism constitutive model is constructed in the framework of irreversible thermodynamics to describe the degeneration of shape memory effect occurring in the thermo-mechanical cyclic defor... A macroscopic based multi-mechanism constitutive model is constructed in the framework of irreversible thermodynamics to describe the degeneration of shape memory effect occurring in the thermo-mechanical cyclic deformation of NiTi shape memory alloys (SMAs). Three phases, austenite A, twinned martensite and detwinned martensite , as well as the phase transitions occurring between each pair of phases (, , , , and are considered in the proposed model. Meanwhile, two kinds of inelastic deformation mechanisms, martensite transformation-induced plasticity and reorientation-induced plasticity, are used to explain the degeneration of shape memory effects of NiTi SMAs. The evolution equations of internal variables are proposed by attributing the degeneration of shape memory effect to the interaction between the three phases (A, , and and plastic deformation. Finally, the capability of the proposed model is verified by comparing the predictions with the experimental results of NiTi SMAs. It is shown that the degeneration of shape memory effect and its dependence on the loading level can be reasonably described by the proposed model. 展开更多
关键词 NiTi SMAs Constitutive model Cyclic degeneration of shape memory effect Transformation-induced plasticity Reorientation-induced plasticity
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Monitoring models for base flow effect and daily variation of dam seepage elements considering time lag effect 被引量:11
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作者 Shao-wei Wang Ying-li Xu +1 位作者 Chong-shi Gu Teng-fei Bao 《Water Science and Engineering》 EI CAS CSCD 2018年第4期344-354,共11页
Affected by external environmental factors and evolution of dam performance, dam seepage behavior shows nonlinear time-varying characteristics. In this study, to predict and evaluate the long-term development trend an... Affected by external environmental factors and evolution of dam performance, dam seepage behavior shows nonlinear time-varying characteristics. In this study, to predict and evaluate the long-term development trend and short-term fluctuation of the dam seepage behavior, two monitoring models were developed, one for the base flow effect and one for daily variation of dam seepage elements. In the first model, to avoid the influence of the time lag effect on the evaluation of seepage variation with the time effect component of seepage elements, the base values of the seepage element and the reservoir water level were extracted using the wavelet multi-resolution analysis method, and the time effect component was separated by the established base flow effect monitoring model. For the development of the daily variation monitoring model for dam seepage elements, all the previous factors, of which the measured time series prior to the dam seepage element monitoring time may have certain influence on the monitored results, were considered. Those factors that were positively correlated with the analyzed seepage element were initially considered to be the support vector machine(SVM) model input factors, and then the SVM kernel function-based sensitivity analysis was performed to optimize the input factor set and establish the optimized daily variation SVM model. The efficiency and rationality of the two models were verified by case studies of the water level of two piezometric tubes buried under the slope of a concrete gravity dam.Sensitivity analysis of the optimized SVM model shows that the influences of the daily variation of the upstream reservoir water level and rainfall on the daily variation of piezometric tube water level are processes subject to normal distribution. 展开更多
关键词 Dam seepage monitoring model Time lag effect Support vector machine(SVM) Sensitivity analysis Base flow Daily variation Piezometric tube water level
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A new approach for time effect analysis of settlement for single pile based on virtual soil-pile model 被引量:9
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作者 吴文兵 王奎华 +1 位作者 张智卿 CHIN Jian Leo 《Journal of Central South University》 SCIE EI CAS 2012年第9期2656-2662,共7页
A new approach is proposed to analyze the settlement behavior for single pile embedded in layered soils. Firstly, soil layers surrounding pile shaft are simulated by using distributed Voigt model, and finite soil laye... A new approach is proposed to analyze the settlement behavior for single pile embedded in layered soils. Firstly, soil layers surrounding pile shaft are simulated by using distributed Voigt model, and finite soil layers under the pile end are assumed to be virtual soil-pile whose cross-section area is the same as that of the pile shaft. Then, by means of Laplace transform and impedance function transfer method to solve the static equilibrium equation of pile, the analytical solution of the displacement impedance fimction at the pile head is derived. Furthermore, the analytical solution of the settlement at the head of single pile is theoretically derived by virtue of convolution theorem. Based on these solutions, the influences of parameters of soil-pile system on the settlement behavior for single pile are analyzed. Also, comparison of the load-settlement response for two well-instrumented field tests in multilayered soils is given to demonstrate the effectiveness and accuracy of the proposed approach. It can be noted that the presented solution can be used to calculate the settlement of single pile for the preliminary design of pile foundation. 展开更多
关键词 SETTLemENT time effect single pile virtual soil-pile model layered soil VISCOELASTICITY distributed Voigt model
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EMPIRICAL BAYES TEST PROBLEMS OF VARIANCE COMPONENTS IN RANDOM EFFECTS MODEL 被引量:3
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作者 韦来生 张伟平 《Acta Mathematica Scientia》 SCIE CSCD 2005年第2期274-282,共9页
Bayes decision rule of variance components for one-way random effects model is derived and empirical Bayes (EB) decision rules are constructed by kernel estimation method. Under suitable conditions, it is shown that t... Bayes decision rule of variance components for one-way random effects model is derived and empirical Bayes (EB) decision rules are constructed by kernel estimation method. Under suitable conditions, it is shown that the proposed EB decision rules are asymptotically optimal with convergence rates near O(n-1/2). Finally, an example concerning the main result is given. 展开更多
关键词 empirical Bayes test variance components random effects model convergence rates
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Surface and thermal effects on vibration of embedded alumina nanobeams based on novel Timoshenko beam model 被引量:3
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作者 B.AMIRIAN R.HOSSEINI-ARA H.MOOSAVI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第7期875-886,共12页
This paper deals with the free vibration analysis of circular alumina (Al2O3) nanobeams in the presence of surface and thermal effects resting on a Pasternak foun- dation. The system of motion equations is derived u... This paper deals with the free vibration analysis of circular alumina (Al2O3) nanobeams in the presence of surface and thermal effects resting on a Pasternak foun- dation. The system of motion equations is derived using Hamilton's principle under the assumptions of the classical Timoshenko beam theory. The effects of the transverse shear deformation and rotary inertia are also considered within the framework of the mentioned theory. The separation of variables approach is employed to discretize the governing equa- tions which are then solved by an analytical method to obtain the natural frequencies of the alumina nanobeams. The results show that the surface effects lead to an increase in the natural frequency of nanobeams as compared with the classical Timoshenko beam model. In addition, for nanobeams with large diameters, the surface effects may increase the natural frequencies by increasing the thermal effects. Moreover, with regard to the Pasternak elastic foundation, the natural frequencies are increased slightly. The results of the present model are compared with the literature, showing that the present model can capture correctly the surface effects in thermal vibration of nanobeams. 展开更多
关键词 surface effect thermal environment alumina nanobeam Pasternak foun-dation Timoshenko beam model
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Phytochemical constituents,analgesic and anti-inflammatory effects of methanol extract of Triumfetta rhomboidea leaves in animal models 被引量:2
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作者 Uche FI Okunna BU 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2009年第5期26-29,共4页
Objective:To investigate the analgesic and anti-inflammatory effects of the methanolic extract of the leaves of Triumfetta rhomboidea on mice and rats respectively.And to screen the phytochemical constituent of the ex... Objective:To investigate the analgesic and anti-inflammatory effects of the methanolic extract of the leaves of Triumfetta rhomboidea on mice and rats respectively.And to screen the phytochemical constituent of the extract. Methods:The analgesic effect was determined by acetic acid-induced writhing test in mice.While the anti-inflammatory activity was determined by egg albumin-induced oedema of the rat paw.Phytochemical screening was done by standard procedures.Results:Triumfetta rhomboidea leaf extract(50 -400 mg/kg) caused a statistically significant inhibition on the egg albumin-induced eodema or inflammation in Wister albino rats with P【0.001(ANOVA).This effect was higher than the observed effect with Piroxicam(0.5 mg/kg) which was used as a standard.The effect was also dose-dependent.Furthermore,Triumfetta rhomboidea extract caused a statistically significant reduction in the number of acetic acid-induced writhing in mice,with P【0.001(ANOVA).These effects were also does-dependent and greater than the analgesic effects by paracetamol which was used as a reference drug.Phytochemical screening revealed the presence of flavonoids,steroids, triterpenoids alkaloids,tannins and saponins in Truimfetta rhomboidea leaf extract.Conclusion:Triumfetta rhomboidea can be recommended for acute inflammatory disorders and diseases associated with pains.This also supports its traditional use as an anti-snake bite and anti-cancer or anti-tumor agent.Further study is on the way to find out the mechanism of its action and also to isolate,identify and characterize the active principle responsible for these effects in this plant. 展开更多
关键词 Triumfetta rhomboidea PHYTOCHemICAL constituents ANTI-INFLAMMATORY ANALGESIC effect ANIMAL models
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Mitigating end effects of EMD using non-equidistance grey model 被引量:4
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作者 Zhi He Yi Shen +3 位作者 Qiang Wang Yan Wang Naizhang Feng Liyong Ma 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第4期603-611,共9页
Aiming at mitigating end effects of empirical mode decomposition (EMD), a new approach motivated by the non- equidistance grey model (NGM) termed as NGM(1,1) is proposed. Other than trapezoid formulas, the cubic... Aiming at mitigating end effects of empirical mode decomposition (EMD), a new approach motivated by the non- equidistance grey model (NGM) termed as NGM(1,1) is proposed. Other than trapezoid formulas, the cubic Hermite spline is put forward to improve the accuracy of derivative to the accumulated generating operation (AGO) series. Hopefully, it is worth stressing that the proposed NGM(1,1) model is particularly useful for predicting uncertainty data. Qualitative and quantitative comparisons between the proposed approach and other well-known algorithms are carried out through computer simulations on synthetic as well as natural signals. Simulation results demonstrate the proposed method can reduce end effects and improve the decomposition results of EMD. 展开更多
关键词 empirical mode decomposition (emD) end effect non-equidistance grey model (NGM).
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Mathematical Model for Tempering Time Effect on Quenched Steel Based on Hollomon Parameter 被引量:2
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作者 Nong WAN Weihao XIONG Jinping SUO 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第6期803-806,共4页
Through the differentiating and integrating process, a mathematical model for tempering time effect on quenched steel was derived based on the attribute of state function and the general equation of Hollomon parameter... Through the differentiating and integrating process, a mathematical model for tempering time effect on quenched steel was derived based on the attribute of state function and the general equation of Hollomon parameter, which correlates the tempering hardness with the tempering time at different tempering temperature. Using the established model, the linear relationship between the tempering hardness and the tempering time in logarithm was proved theoretically, and the tempering hardness for various tempering time was reduced to the measurement and calculation of a hardness experiment tempered for 1 h at different tempering temperatures. Moreover, the hardness of steel 42CrMo and T8Mn tempered for various times at 200-600℃ was calculated using this method. The predicted results are in good agreement with those of the available experiments. 展开更多
关键词 TemPERING Time effect Mathematical model Hollomon parameter
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An improved EEHEMT model for kink effect on AlGaN/GaN HEMT 被引量:2
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作者 曹梦逸 卢阳 +5 位作者 魏家行 陈永和 李卫军 郑佳欣 马晓华 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第8期452-456,共5页
In this paper, a new current expression based on both the direct currect (DC) characteristics of the A1GaN/GaN high election mobility transistor (HEMT) and the hyperbolic tangent function tanh is proposed, by whic... In this paper, a new current expression based on both the direct currect (DC) characteristics of the A1GaN/GaN high election mobility transistor (HEMT) and the hyperbolic tangent function tanh is proposed, by which we can describe the kink effect of the A1GaN/GaN HEMT well. Then, an improved EEHEMT model including the proposed current expression is presented. The simulated and measured results of Ⅰ-Ⅴ, S-parameter, and radio frequency (RF) large-signal characteristics are compared for a self-developed on-wafer A1GaN/GaN HEMT with ten gate fingers each being 0.4-μm long and 125-p-m wide (Such an A1GaN/GaN HEMT is denoted as A1GaN/GaN HEMT (10 × 125 μm)). The improved large signal model simulates the Ⅰ-Ⅴ characteristic much more accurately than the original one, and its transconductance and RF characteristics are also in excellent agreement with the measured data. 展开更多
关键词 A1GaN/GaN HemT kink effect tanh EEHemT model
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