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Comprehensive security risk factor identification for small reservoirs with heterogeneous data based on grey relational analysis model 被引量:6
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作者 Jing-chun Feng Hua-ai Huang +1 位作者 Yao Yin Ke Zhang 《Water Science and Engineering》 EI CAS CSCD 2019年第4期330-338,共9页
Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when ... Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when data are incomplete.The existing grey relational models have some disadvantages in measuring the correlation between categorical data sequences.To this end,this paper introduces a new grey relational model to analyze heterogeneous data.In this study,a set of security risk factors for small reservoirs was first constructed based on theoretical analysis,and heterogeneous data of these factors were recorded as sequences.The sequences were regarded as random variables,and the information entropy and conditional entropy between sequences were measured to analyze the relational degree between risk factors.Then,a new grey relational analysis model for heterogeneous data was constructed,and a comprehensive security risk factor identification method was developed.A case study of small reservoirs in Guangxi Zhuang Autonomous Region in China shows that the model constructed in this study is applicable to security risk factor identification for small reservoirs with heterogeneous and sparse data. 展开更多
关键词 Security risk factor identification Heterogeneous data Grey relational analysis model Relational degree Information entropy Conditional entropy Small reservoir GUANGXI
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Study on Analysis Model of Millet Yield Loss Caused by Weeds in Summer Season Millet Field
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作者 Lv Peng Duan Xishun +7 位作者 Liu Hongxia Hou Shenglin Bo Kuiyong Wang Xinyu Xiang Jinying Ma Xue Jia Haiyan Zhou Hanzhang 《Plant Diseases and Pests》 CAS 2013年第2期36-39,共4页
Weed management in summer season foxtall millet field was studied by evaluating weed damage and exploring competition between weeds and foxtail millet, and a few fitting models were simulated and compared by employing... Weed management in summer season foxtall millet field was studied by evaluating weed damage and exploring competition between weeds and foxtail millet, and a few fitting models were simulated and compared by employing field plot experiment and nonlinear regression analysis. The results showed that the millet yield losses and weed density were extremely significantly correlated. Among the tested models, the determination coefficient ( R2 ) of hyperbolic model was 0.997 12, and minimum residual sum of squares was 16.174, which was considered the optimal model to simulate the competition relation between weeds and millet. The predicted equation was Y = d/( 1. 733 + 0. 018d) ; the interspecific competitiveness of weeds was 0. 577 0 and the intraspecific competitiveness was 0.010 3 ; the maximum loss rate of millet yield was 55.56%. This study had established an analysis model with high gcodness-of-fit and practical prediction which could help weed management in summer season millet field. 展开更多
关键词 Millet field WEEDS Yield loss analysis model
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Research on the Land Consolidation Strategy of Dalian City Based on PESTEL Analysis Model
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作者 Hongcheng WANG Junchao CHEN 《Meteorological and Environmental Research》 CAS 2020年第4期1-5,13,共6页
Standing at the starting point of the"13 th Five-Year Plan",the general situation of Dalian City,the current status and characteristics of land use,and the strategy of land consolidation planning during the&... Standing at the starting point of the"13 th Five-Year Plan",the general situation of Dalian City,the current status and characteristics of land use,and the strategy of land consolidation planning during the"12 th Five-Year Plan"period are analyzed,and then the political,economic,social,technological,environmental and legal factors that influence the land consolidation of Dalian City are analyzed based on the PESTEL model.Afterwards,measures of land consolidation in Dalian City during the"13 th Five-Year Plan"period are proposed,such as transforming the concept of land consolidation,coordinating opinions of agricultural departments and making scientific decisions,reasonably arranging agricultural space,optimizing the layout of rural residential areas and encouraging moderate scale management of land,broadening the content of land consolidation,and implementing soil testing fertilization. 展开更多
关键词 Land management Land consolidation strategy PESTEL analysis model Dalian City
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Security Risk Analysis Model for Identification and Resolution System of Industrial Internet
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作者 MA Baoluo CHEN Wenqu CHI Cheng 《ZTE Communications》 2020年第1期49-54,共6页
Identification and resolution system of the industrial Internet is the“neural hub”of the industrial Internet for coordination.Catastrophic damage to the whole industrial Internet industry ecology may be caused if th... Identification and resolution system of the industrial Internet is the“neural hub”of the industrial Internet for coordination.Catastrophic damage to the whole industrial Internet industry ecology may be caused if the identification and resolution system is attacked.Moreover,it may become a threat to national security.Therefore,security plays an important role in identification and resolution system of the industrial Internet.In this paper,an innovative security risk analysis model is proposed for the first time,which can help control risks from the root at the initial stage of industrial Internet construction,provide guidance for related enterprises in the early design stage of identification and resolution system of the industrial Internet,and promote the healthy and sustainable development of the industrial identification and resolution system. 展开更多
关键词 industrial Internet identification and resolution system security risk analysis model
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A Requirements Analysis Model Based on QFD
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作者 Nelson K.H. Tang 《Journal of Electronic Science and Technology of China》 2004年第4期87-92,共6页
The enterprise resource planning (ERP) system has emerged to offer an integrated IT solution and more and more enterprises are increasing by adopting this system and regarding it as an important innovation. However, t... The enterprise resource planning (ERP) system has emerged to offer an integrated IT solution and more and more enterprises are increasing by adopting this system and regarding it as an important innovation. However, there is already evidence of high failure risks in ERP project implementation, one major reason is poor analysis of the requirements for system implementation. In this paper, the importance of requirements analysis for ERP project implementation is highlighted, and a requirements analysis model by applying quality function deployment (QFD) is presented, which will support to conduct requirements analysis for ERP project. 展开更多
关键词 ERP requirements analysis model QFD BSC VCA
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Modeling Analysis of Factors Influencing Wind-Borne Seed Dispersal: A Case Study on Dandelion
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作者 Kemeng Xue 《American Journal of Plant Sciences》 CAS 2024年第4期252-267,共16页
A weed is a plant that thrives in areas of human disturbance, such as gardens, fields, pastures, waysides, and waste places where it is not intentionally cultivated. Dispersal affects community dynamics and vegetation... A weed is a plant that thrives in areas of human disturbance, such as gardens, fields, pastures, waysides, and waste places where it is not intentionally cultivated. Dispersal affects community dynamics and vegetation response to global change. The process of seed disposal is influenced by wind, which plays a crucial role in determining the distance and probability of seed dispersal. Existing models of seed dispersal consider wind direction but fail to incorporate wind intensity. In this paper, a novel seed disposal model was proposed in this paper, incorporating wind intensity based on relevant references. According to various climatic conditions, including temperate, arid, and tropical regions, three specific regions were selected to establish a wind dispersal model that accurately reflects the density function distribution of dispersal distance. Additionally, dandelions growth is influenced by a multitude of factors, encompassing temperature, humidity, climate, and various environmental variables that necessitate meticulous consideration. Based on Factor Analysis model, which completely considers temperature, precipitation, solar radiation, wind, and land carrying capacity, a conclusion is presented, indicating that the growth of seeds is primarily influenced by plant attributes and climate conditions, with the former exerting a relatively stronger impact. Subsequently, the remaining two plants were chosen based on seed weight, yielding consistent conclusion. 展开更多
关键词 Seed Dispersal Wind Intensity Climatic Effect Factor analysis model
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Prototyping an open environment for sharing geographical analysis models on cloud computing platform 被引量:5
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作者 Yongning Wen Min Chen +3 位作者 Guonian Lu Hui Lin Li He Songshan Yue 《International Journal of Digital Earth》 SCIE EI 2013年第4期356-382,共27页
The sharing of geographical analysis models is of crucial importance for simulating geographic processes and phenomena in the current geographical information systems(e.g.Digital Earth),but there remain some issues th... The sharing of geographical analysis models is of crucial importance for simulating geographic processes and phenomena in the current geographical information systems(e.g.Digital Earth),but there remain some issues that have not been completely resolved.The challenges include,eliminating model heterogeneity and searching for suitable infrastructures to support the open sharing and effective execution of models.Taking advantage of cloud computing,this article aims to address the above issues and develop an open environment for geographical analysis model sharing.On the basis of the analysis of the applicability of cloud computing,the architecture of the open environment is proposed.More importantly,key strategies designed for heterogeneous model description,model encapsulating as well as model deploying and transparent accessing in the cloud are discussed in detail to establish such an environment.Finally,the prototype environment is implemented,and experiments were conducted to verify the environment’s feasibility to support the sharing of geographical analysis models. 展开更多
关键词 geographical analysis models cloud computing open environment
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Operating mechanism and set pair analysis model of a sustainable water resources system 被引量:1
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作者 Chaoyang DU Jingjie YU +1 位作者 Huaping ZHONG Dandan WANG 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2015年第2期288-297,共10页
There is no altemative to the world's water resources, and their increasing scarcity is making it difficult to meet the world population's water needs. This paper presents a sustainable water resources system (SWRS... There is no altemative to the world's water resources, and their increasing scarcity is making it difficult to meet the world population's water needs. This paper presents a sustainable water resources system (SWRS) and analyzes the operating mechanism that makes it possible to evaluate the status of such a system. A SWRS can be described as a complex coupling system that integrates water resources, social, economic and ecological systems into a whole. The SWRS's operating mechanism is composed of dynamic, resistance and coordination components, and it interacts with and controls the system's evolution process. The study introduces a new approach, set pair analysis theory, to measure the state of a SWRS, and an evaluation index system is established using the subsystems and operating mechanism of a SWRS. The evaluation index system is separated into three levels (goal level, criteria level and index level) and divides the index standard into five grades. An evaluation model of the SWRS based on set pair analysis theory is constructed, and an example of SWRS evaluation in Shanghai is presented. The connection degrees of the index in the three levels are calculated, and the connection degree of the goal index is calculated to be 0.342, which classifies the city's SWRS condition as grade 2. The sustainable use of water resources in the region is determined to be at a relatively adequate level that meets the requirements of sustainable development. 展开更多
关键词 Keywords sustainable water resources system operatingmechanism set pair analysis model SHANGHAI
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Cost analysis model for catalytic conversion of syngas in to light hydrocarbon gases 被引量:1
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作者 Yangyang Deng Prem B.Parajuli Hakkwan Kim 《Information Processing in Agriculture》 EI 2015年第1期37-50,共14页
Bio-gasification is a new technology and considered as a more efficient way to utilize bioenergy.The economic feasibility becomes one of the greatest issues when we apply this new technology.Evaluation of economic fea... Bio-gasification is a new technology and considered as a more efficient way to utilize bioenergy.The economic feasibility becomes one of the greatest issues when we apply this new technology.Evaluation of economic feasibility of a bio-gasification facility needs better understanding of its production unit cost under different capacities and different working shift modes.The objective of this study was to evaluate the unit cost of biofuel products(Liquid HCs,Light HCs and Oxygenates CxHyOz)under different capacities using a modeling method.The cost analysis model was developed using Visual Basic Microsoft 2008,computer programming language and mathematical equations.The modeling results showed that the unit costs of biofuel product from bio-gasification facility were significantly affected by production capacities of facilities.As the facility capacity increased from 65 to 10,000 N m^3 h^-1,the biofuel production unit cost of gas(Light HCs),oil(Liquid HCs),and aqueous(Oxygenates CxHyOz)decreased from$38.92 per MMBTU,$30.89 per gallon and$25.74 per gallon to$2.01 per MMBTU,$1.59 per gallon,and$1.33 per gallon,respectively.The results of the sensitivity analysis showed that feedstock cost was the most sensitive cost factor on unit costs for all biofuel products at high capacity.The cost analysis model developed in this study could be used to optimize production unit costs of bio-fuel products from bio-gasification facility. 展开更多
关键词 BIOFUEL Bio-gasification Cost analysis model Production capacity Unit cost
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Transient pressure analysis of polymer flooding fractured wells with oil-water two-phase flow
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作者 WANG Yang YU Haiyang +2 位作者 ZHANG Jia FENG Naichao CHENG Shiqing 《Petroleum Exploration and Development》 2023年第1期175-182,共8页
The oil-water two-phase flow pressure-transient analysis model for polymer flooding fractured well is established by considering the comprehensive effects of polymer shear thinning,shear thickening,convection,diffusio... The oil-water two-phase flow pressure-transient analysis model for polymer flooding fractured well is established by considering the comprehensive effects of polymer shear thinning,shear thickening,convection,diffusion,adsorption retention,inaccessible pore volume and effective permeability reduction.The finite volume difference and Newton iteration methods are applied to solve the model,and the effects of fracture conductivity coefficient,injected polymer mass concentration,initial polymer mass concentration and water saturation on the well-test type curves of polymer flooding fractured wells are discussed.The results show that with the increase of fracture conductivity coefficient,the pressure conduction becomes faster and the pressure drop becomes smaller,so the pressure curve of transitional flow goes downward,the duration of bilinear flow becomes shorter,and the linear flow appears earlier and lasts longer.As the injected polymer mass concentration increases,the effective water phase viscosity increases,and the pressure loss increases,so the pressure and pressure derivative curves go upward,and the bilinear flow segment becomes shorter.As the initial polymer mass concentration increases,the effective water phase viscosity increases,so the pressure curve after the wellbore storage segment moves upward as a whole.As the water saturation increases,the relative permeability of water increases,the relative permeability of oil decreases,the total oil-water two-phase mobility becomes larger,and the pressure loss is reduced,so the pressure curve after the wellbore storage segment moves downward as a whole.The reliability and practicability of this new model are verified by the comparison of the results from simplified model and commercial well test software,and the actual well test data. 展开更多
关键词 fractured vertical well polymer flooding two-phase flow well test analysis model type curve influence factor
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Experimental Study and Model Analysis of the Performance of IPMC Membranes with Various Thickness 被引量:12
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作者 Qingsong He Min Yu +3 位作者 Linlin Song Haitao Ding Xiaoqing Zhang Zhendong Dai 《Journal of Bionic Engineering》 SCIE EI CSCD 2011年第1期77-85,共9页
Ionic Polymer-Metal Composite (IPMC) is a new electro-active polymer, which has the advantages of light weight, flexibility, and large stroke with low driving voltage. Because of these features, IPMC can be applied ... Ionic Polymer-Metal Composite (IPMC) is a new electro-active polymer, which has the advantages of light weight, flexibility, and large stroke with low driving voltage. Because of these features, IPMC can be applied to bionic robotic actuators, artificial muscles, as well as dynamic sensors. However, IPMC has the major drawback of low generative blocking force. In this paper, in order to enhance the blocking force, the Nation membranes with thickness of 0.22 mm, 0.32 mm, 0.42 mm, 0.64 mm and 0.8 mm were prepared by casting from liquid solution. By employing these Nation membranes, IPMCs with varying thickness were fabricated by electroless plating. The elastic modulus of the casted Nation membranes were obtained by a nano-indenter, and the current, the displacement and the blocking force were respectively measured by the apparatus for actuation test. Finally, the effects of the thickness on the performance of IPMC were analyzed with an electromechanical model. Experimental study and theory analysis indicate that as the thickness increases, the elastic modulus of Nation membrane and the blocking force of IPMC increase, however, the current and the displacement decrease. 展开更多
关键词 IPMC Nation membranes electroless plating actuation test model analysis
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Parameter identification and global sensitivity analysis of Xin'anjiang model using meta-modeling approach 被引量:12
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作者 Xiao-meng SONG Fan-zhe KONG +2 位作者 Che-sheng ZHAN Ji-wei HAN Xin-hua ZHANG 《Water Science and Engineering》 EI CAS CSCD 2013年第1期1-17,共17页
Parameter identification, model calibration, and uncertainty quantification are important steps in the model-building process, and are necessary for obtaining credible results and valuable information. Sensitivity ana... Parameter identification, model calibration, and uncertainty quantification are important steps in the model-building process, and are necessary for obtaining credible results and valuable information. Sensitivity analysis of hydrological model is a key step in model uncertainty quantification, which can identify the dominant parameters, reduce the model calibration uncertainty, and enhance the model optimization efficiency. There are, however, some shortcomings in classical approaches, including the long duration of time and high computation cost required to quantitatively assess the sensitivity of a multiple-parameter hydrological model. For this reason, a two-step statistical evaluation framework using global techniques is presented. It is based on (1) a screening method (Morris) for qualitative ranking of parameters, and (2) a variance-based method integrated with a meta-model for quantitative sensitivity analysis, i.e., the Sobol method integrated with the response surface model (RSMSobol). First, the Morris screening method was used to qualitatively identify the parameters' sensitivity, and then ten parameters were selected to quantify the sensitivity indices. Subsequently, the RSMSobol method was used to quantify the sensitivity, i.e., the first-order and total sensitivity indices based on the response surface model (RSM) were calculated. The RSMSobol method can not only quantify the sensitivity, but also reduce the computational cost, with good accuracy compared to the classical approaches. This approach will be effective and reliable in the global sensitivity analysis of a complex large-scale distributed hydrological model. 展开更多
关键词 Xin'anjiang model global sensitivity analysis parameter identification meta-modeling approach response surface model
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Association between Macroscopic-factors and Identified HIV/AIDS Cases among Injecting Drug Users: An Analysis Using Geographically Weighted Regression Model 被引量:1
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作者 XING Jian Nan GUO Wei +5 位作者 QIAN Sha Sha DING Zheng Wei CHEN Fang Fang PENG Zhi Hang QIN Qian Qian WANG Lu 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第4期311-318,共8页
Drug use (DU), particularly injecting drug use (IDU) has been the main route of transmission and spread of Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDSJ among injecting drug use... Drug use (DU), particularly injecting drug use (IDU) has been the main route of transmission and spread of Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDSJ among injecting drug users (IDUs)[1]. Previous studies have proven that needles or cottons sharing during drug injection were major risk factors for HIV/AIDS transmission at the personal level[z4]. Being a social behavioral issue, HIV/AIDS related risk factors should be far beyond the personal level. Therefore, studies on HIV/AIDS related risk factors should focus not only on the individual factors, but also on the association between HIV/AIDS cases and macroscopic-factors, such as economic status, transportation, health care services, etc[1]. The impact of the macroscopic-factors on HIV/AIDS status might be either positive or negative, which are potentially reflected in promoting, delaying or detecting HIV/AIDS epidemics. 展开更多
关键词 AIDS HIV An analysis Using Geographically Weighted Regression model
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Parameters Sensitivity Analysis and Correction for Concrete Damage Plastic Model 被引量:1
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作者 Yaqin Jiang Pengfei Xu +1 位作者 Chengzhi Wang Dianshu Liu 《Journal of Beijing Institute of Technology》 EI CAS 2018年第1期103-108,共6页
In order to understand the effect of hardening ductility parameters and softening ductility parameters of the concrete damage plastic model in LS-DYNA,a sensitivity and reliability analysis of these parameters through... In order to understand the effect of hardening ductility parameters and softening ductility parameters of the concrete damage plastic model in LS-DYNA,a sensitivity and reliability analysis of these parameters through a convenient cube unit test was conducted. The results showed that the peak strength strain was independent of the hardening ductility parameter DH,but affected by AH,BH,and CH. The softening ductility was mainly related to the softening ductility parameter AS,but not affected by the damage ductility exponent BS. In case that the model with default parameters failed to match the AS-controlled damage softening phase,an optimized model with an AS correction was developed. The corrected model with the AS value of 2 matched well with the code model,and exhibited good feasibility in predicting the stress-strain curve of different grades of concrete. Moreover,the practicability of the corrected model was further validated by the conventional triaxial test. The simulated curve exhibited favorable consistence with the trial curve. Therefore,the model with parameter correction could provide a prospective reference for predicting the mechanical properties of concrete. 展开更多
关键词 damage-plastic model concrete sensitivity analysis parameter correction
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Analysis of sp Pillar Stability Experiment: Continuous thermo-mechanical model development and calibration 被引量:1
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作者 R. Blaheta P. Byczanski +5 位作者 M. ermák R. Hrtus R. Kohut A. Kolcun J. Malík S. Sysala 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2013年第2期124-135,共12页
The paper describes an analysis of thermo-mechanical (TM) processes appearing during the Aspo Pillar Stability Experiment (APSE). This analysis is based on finite elements with elasticity, plasticity and dam- age ... The paper describes an analysis of thermo-mechanical (TM) processes appearing during the Aspo Pillar Stability Experiment (APSE). This analysis is based on finite elements with elasticity, plasticity and dam- age mechanics models of rock behaviour and some least squares calibration techniques. The main aim is to examine the capability of continuous mechanics models to predict brittle damage behaviour of gran- ite rocks. The performed simulations use an in-house finite element software GEM and self-developed experimental continuum damage MATLAB code. The main contributions are twofold. First, it is an inverse analysis, which is used for (1) verification of an initial stress measurement by back analysis of conver- gence measurement during construction of the access tunnel and (2) identification of heat transfer rock mass properties by an inverse method based on the known heat sources and temperature measurements. Second, three different hierarchically built models are used to estimate the pillar damage zones, i.e. elas- tic model with Drucker-Prager strength criterion, elasto-plastic model with the same yield limit and a combination of elasto-plasticity with continuum damage mechanics. The damage mechanics model is also used to simulate uniaxial and triaxial compressive strength tests on the ,Aspo granite. 展开更多
关键词 In situ pillar stability experiment Continuous mechanics Damage of granite rocks model calibration by back analysis Finite element method (FEM)
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A Multifractal Detrended Fluctuation Analysis of the Ising Financial Markets Model with Small World Topology 被引量:1
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作者 张昂辉 李晓温 +1 位作者 苏桂锋 张一 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期13-16,共4页
We present a multifractal detrended fluctuation analysis (MFDFA) of the time series of return generated by our recently-proposed Ising financial market model with underlying small world topology. The result of the M... We present a multifractal detrended fluctuation analysis (MFDFA) of the time series of return generated by our recently-proposed Ising financial market model with underlying small world topology. The result of the MFDFA shows that there exists obvious multifractal scaling behavior in produced time series. We compare the MFDFA results for original time series with those for shuffled series, and find that its multifractal nature is due to two factors: broadness of probability density function of the series and different correlations in small- and large-scale fluctuations. This may provide new insight to the problem of the origin of multifractality in financial time series. 展开更多
关键词 A Multifractal Detrended Fluctuation analysis of the Ising Financial Markets model with Small World Topology
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Fifth-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Nonlinear Systems (5th-CASAM-N): II. Paradigm Application to a Bernoulli Model Comprising Uncertain Parameters 被引量:1
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作者 Dan Gabriel Cacuci 《American Journal of Computational Mathematics》 2022年第1期119-161,共43页
This work presents the application of the recently developed “Fifth-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Nonlinear Systems (5<sup>th</sup>-CASAM-N)” to a simplified Bernoulli ... This work presents the application of the recently developed “Fifth-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Nonlinear Systems (5<sup>th</sup>-CASAM-N)” to a simplified Bernoulli model. The 5<sup>th</sup>-CASAM-N builds upon and incorporates all of the lower-order (i.e., the first-, second-, third-, and fourth-order) adjoint sensitivities analysis methodologies. The Bernoulli model comprises a nonlinear model response, uncertain model parameters, uncertain model domain boundaries and uncertain model boundary conditions, admitting closed-form explicit expressions for the response sensitivities of all orders. Illustrating the specific mechanisms and advantages of applying the 5<sup>th</sup>-CASAM-N for the computation of the response sensitivities with respect to the uncertain parameters and boundaries reveals that the 5<sup>th</sup>-CASAM-N provides a fundamental step towards overcoming the curse of dimensionality in sensitivity and uncertainty analysis. 展开更多
关键词 Fifth-Order Sensitivity analysis of Bernoulli model Uncertain model Parameters Uncertain model Domain Boundaries Uncertain model Boundary Conditions
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A j,υ model for the analysis and prediction of tides
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作者 Chen Zongyong, Huang Zuke, Zhou Tianhua, Tang Enxiang and Wang Yuzhou Ocean University of Qingdao,Qingdao,China No, 57653 Unit of Chinese People’s Liberation Army,China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第4期475-486,共12页
In this paper, the j, υ corrected formulae of the amplitudes and the phases of 58 astronomical constituents are given, and the models for the analysis and prediction of 169 constituents are presented. The new Cartwri... In this paper, the j, υ corrected formulae of the amplitudes and the phases of 58 astronomical constituents are given, and the models for the analysis and prediction of 169 constituents are presented. The new Cartwright's calculated results of the tidal potential are used, and the quadratic analysis is made. It has been proved by a number of trials that the harmonic constants of constituents are more stable and the accuracy of the predicted result reliable. 展开更多
关键词 model for the analysis and prediction of tides A j
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Stability Analysis of the Viscous Polytropic Dark Energy Model in Einstein Cosmology
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作者 王玥懿 陈菊华 王永久 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第10期15-18,共4页
The viscous polytropic gas model as one model of dark energy is hot-spot and keystone to the modern cosmology. We study the evolution of the viscous polytropic dark energy model interacting with the dark matter in the... The viscous polytropic gas model as one model of dark energy is hot-spot and keystone to the modern cosmology. We study the evolution of the viscous polytropic dark energy model interacting with the dark matter in the Einstein cosmology. Setting the autonomous dynamical system for the interacting viscous polytropic dark energy with dark matter and using the phase space analysis method to investigate the dynamical evolution and its critical stability, we find that the viscosity property of the dark energy creates a benefit for the stable critical dynamical evolution of the interaction model between dark matter and dark energy in the flat Friedmann-Robertson-Walker universe and the viscosity of dark energy will soften the coincidence problem just like the interacting dark energy model. 展开更多
关键词 of on it Stability analysis of the Viscous Polytropic Dark Energy model in Einstein Cosmology FRW for is in
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Spatial Analysis and Modelling of Wind Farm Site Suitability in Nasarawa State, North-Central Nigeria
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作者 Chukwunonso Emmanuel Ozim Anita Odionyenfe Nweke +3 位作者 Salamatu Abraham Ekpo Olufemi Stephen Oladeinde Haruna Kuje Ayuba Udochukwu Michael Mbanaso 《Journal of Geographic Information System》 2021年第5期603-630,共28页
There has been an increasing global and local interest in developing renewable, clean, and cheap energy towards achieving Goal number 7 of the Sustainable Development Goals (SDG). However, decisions involving suitable... There has been an increasing global and local interest in developing renewable, clean, and cheap energy towards achieving Goal number 7 of the Sustainable Development Goals (SDG). However, decisions involving suitable and sustainable locations for renewable energy projects remain an important task. This study employed Geographic Information System (GIS) and Multi-Criteria Decision Analysis (MCDA) to spatially analyze and model wind farm site suitability in Nasarawa State. The aim is to integrate the environmental, social, and economic aspects of decision-making for identifying sustainable wind farm sites. The study distinguished between two sets of decision criteria: decision constraints and decision factors. The former defined the exclusion zones while the latter were standardized based on fuzzy logic to depict varying degrees of suitability across the State. The MCDA applied the weighted linear combination method, with relative weights generated through pairwise comparisons of the analytic hierarchy process to analyze three policy scenarios: equal weights, environmental/social priority, and economic priority scenario. A combination of resulting composite maps from the constraints and the factors gave the final suitability maps. The resulting suitability index (SI) for the respective policy scenario describes the degrees of suitability: Ideal locations were denoted by one (1) and the not suitable locations by zero (0), with values in-between depicting varying degrees of wind farm site suitability. Based on the SI, priority locations indicating areas with good prospects, in addition to the most suitable parcels of land, were identified and delineated. The composite decision constraint revealed that wind farm projects would not be viable in more than half (57.58%) of the State. Wind speed was the major constraint and accounted for the exclusion of 46.25%, with a mean fuzzy membership value of 0.2008 indicating low suitability across the State. Also, the average acceptable wind farm location for the three-policy scenario was 33.33% of the entire study area. Lafia, Obi, Keana, Awe, Nasarawa-Eggon, Wamba and Kokona LGAs were the identified priority Local Government Areas (LGAs). However, only Lafia, Obi, and Nasarawa-Eggon were consistent with changes in the policy objectives. All the priority LGAs have one or more of the most suitable parcels within their administrative boundaries except for Wamba. Despite the severe limitations of wind speed, substantial parts of Nasarawa State still provide great development potentials for wind energy. The “most suitable” locations in Lafia, Nasarawa-Eggon, and Obi LGAs should have first consideration for the development of wind energy in the State. 展开更多
关键词 GIS Multi-Criteria Spatial analysis and modelling Wind Energy Farm Site Suitability Nasarawa State Nigeria
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