Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and ...Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and build a workflow meta model supporting ABC. Firstly, the concept and concept model of activity based costing (ABC) are introduced. Next, the meta model of P -PROCE (Process, Product, Resource, Organization, and Cost & Evaluation) is presented. Then the cost meta model is defined by adding ABC to P -PROCE model. Object constraint language (OCL) is used to express meta model and constraints. Finally, we show an enterprise modeling and simulation tool based on the workflow meta model. We can systematically construct an enterprise model and easily and efficiently conduct simulation. Moreover it enables us to analyze and evaluate business processes and its costs.展开更多
Wheat is a critical crop,extensively consumed worldwide,and its production enhancement is essential to meet escalating demand.The presence of diseases like stem rust,leaf rust,yellow rust,and tan spot significantly di...Wheat is a critical crop,extensively consumed worldwide,and its production enhancement is essential to meet escalating demand.The presence of diseases like stem rust,leaf rust,yellow rust,and tan spot significantly diminishes wheat yield,making the early and precise identification of these diseases vital for effective disease management.With advancements in deep learning algorithms,researchers have proposed many methods for the automated detection of disease pathogens;however,accurately detectingmultiple disease pathogens simultaneously remains a challenge.This challenge arises due to the scarcity of RGB images for multiple diseases,class imbalance in existing public datasets,and the difficulty in extracting features that discriminate between multiple classes of disease pathogens.In this research,a novel method is proposed based on Transfer Generative Adversarial Networks for augmenting existing data,thereby overcoming the problems of class imbalance and data scarcity.This study proposes a customized architecture of Vision Transformers(ViT),where the feature vector is obtained by concatenating features extracted from the custom ViT and Graph Neural Networks.This paper also proposes a Model AgnosticMeta Learning(MAML)based ensemble classifier for accurate classification.The proposedmodel,validated on public datasets for wheat disease pathogen classification,achieved a test accuracy of 99.20%and an F1-score of 97.95%.Compared with existing state-of-the-art methods,this proposed model outperforms in terms of accuracy,F1-score,and the number of disease pathogens detection.In future,more diseases can be included for detection along with some other modalities like pests and weed.展开更多
目的基于贝叶斯网状Meta分析(Bayesian Network Meta-analysis,BNMA)方法,评价临床常用的口服或鼻饲中成药治疗脑出血(Intracerebral haemorrhage,ICH)术后的有效性及安全性。方法检索中国知网(CNKI)、万方数据知识服务平台(Wanfang)、...目的基于贝叶斯网状Meta分析(Bayesian Network Meta-analysis,BNMA)方法,评价临床常用的口服或鼻饲中成药治疗脑出血(Intracerebral haemorrhage,ICH)术后的有效性及安全性。方法检索中国知网(CNKI)、万方数据知识服务平台(Wanfang)、维普中文期刊(VIP)、中国生物医学文献服务系统(SinoMed)、PubMed、Embase、Cochrane Library、Web of Science建库至2023年8月25日有关中成药干预ICH术后的随机对照试验(randomized controlled trial,RCT);使用ROB 2.0进行偏倚风险评估,运用R 4.2.2加载BUGSnet 1.1.0程序包进行BNMA。结果共纳入28项RCT,总样本量2530例,涵盖9种口服中成药[安宫牛黄丸(AGNH)、苏合香丸(SHX)、脑血疏口服液(NXS)、脑心通胶囊(NXT)、脑血康片(NXK)、消瘀康胶囊(XYK)、养血清脑颗粒(YXQN)、通天口服液(TT)、三七通舒胶囊(SQTS)],所有患者均行手术治疗和术后常规西医治疗(conventional western medicine treatment,CWMT),试验组加用口服或鼻饲中成药。BNMA结果显示,AGNH+CWMT组在降低短期病死率、美国国立卫生研究院卒中量表评分(National Institute of Health stroke scale,NIHSS)和脑血肿周围水肿量方面排第1位,与CWMT组比较P<0.05;SHX+CWMT组在提高总有效率方面排第1位,与CWMT组比较P<0.05;TT+CWMT组在增加格拉斯哥昏迷评分(Glasgow Coma Scale,GCS)方面排第1位,与CWMT组比较P<0.05;YXQN+CWMT组在提高巴塞尔指数(Barthel index,BI)方面排第1位,与CWMT组比较P<0.05;NXS+CWMT组在促进脑血肿吸收量方面排第1位,与CWMT组比较P>0.05;NXT+CWMT组在缩短平均住院时间方面排第1位,与CWMT组比较P>0.05。结论与CWMT组比较,脑出血术后患者在CWMT基础上联用中成药治疗在提高总有效率,降低病死率、NIHSS评分,提高GCS评分、BI指数方面疗效确切,但在促进血肿吸收和缩短平均住院时间方面差异无统计学意义。AGNH综合疗效较好,可能为治疗ICH术后综合疗效最优的中成药。但由于纳入研究质量和方法学的局限性,所得结论仍需进一步验证。展开更多
目的:评价基于跨理论模型的护理干预对2型糖尿病病人自我管理能力等方面的干预效果。方法:检索PubMed、Web of Science、the Cochrane Library、Embase、中国知网、维普数据库、万方数据库和中国生物医学文献数据库,检索时限为建库至202...目的:评价基于跨理论模型的护理干预对2型糖尿病病人自我管理能力等方面的干预效果。方法:检索PubMed、Web of Science、the Cochrane Library、Embase、中国知网、维普数据库、万方数据库和中国生物医学文献数据库,检索时限为建库至2023年1月11日,收集基于跨理论模型的护理干预提高2型糖尿病病人自我管理能力的随机对照试验,采用RevMan 5.2软件进行数据分析。结果:共纳入12篇文献,共计1513例病人。Meta分析结果显示,基于跨理论模型的护理干预可提高病人自我管理能力[SMD=0.69,95%CI(0.50,0.88),P<0.05]、自我效能[SMD=0.85,95%CI(0.64,1.06),P<0.05],改善生活质量[SMD=0.79,95%CI(0.18,1.40),P<0.05]。结论:现有证据表明基于跨理论模型的护理干预可以有效提高2型糖尿病病人的自我管理能力和自我效能,改善病人的生活质量,目前还需要大样本、高质量的临床研究验证结果。展开更多
目的:系统评价基于互联网的院外管理模式对食管癌术后病人的干预效果。方法:系统检索中国知网、维普数据库、万方数据库、中国生物医学文献数据库、EMbase、PubMed、Web of Science、MedLine、the Cochrane Library中有关基于互联网的...目的:系统评价基于互联网的院外管理模式对食管癌术后病人的干预效果。方法:系统检索中国知网、维普数据库、万方数据库、中国生物医学文献数据库、EMbase、PubMed、Web of Science、MedLine、the Cochrane Library中有关基于互联网的院外管理模式干预食管癌术后病人的随机对照试验和类试验研究,检索时限为建库至2022年12月1日,由2名研究员完成文献筛选、质量评价、数据提取,采用RevMan 5.3软件进行Meta分析。结果:共纳入9篇文献,涉及720例病人。Meta分析结果显示,基于互联网的院外管理模式可提高病人的生活质量[MD=9.24,95%CI(7.55,10.92),P<0.00001],降低术后吻合口狭窄发生率[RR=0.31,95%CI(0.17,0.59),P=0.0003],提高病人自我护理能力[MD=5.39,95%CI(4.23,6.55),P<0.00001]、护理满意度[RR=1.37,95%CI(1.18,1.59),P<0.0001)]。结论:现有证据表明,基于互联网的院外管理模式能提高病人生活质量,降低吻合口狭窄发生率,增强自我护理能力,提高护理满意度,促进病人康复。展开更多
目的:激素性股骨头坏死家兔模型是最常用的股骨头坏死动物模型,其股骨头病理学改变与临床较为接近,但目前国内外报道的造模条件、方法和评价标准等均不统一,导致所建立动物模型的科学价值低、难于推广应用。此次研究旨在明确不同造模条...目的:激素性股骨头坏死家兔模型是最常用的股骨头坏死动物模型,其股骨头病理学改变与临床较为接近,但目前国内外报道的造模条件、方法和评价标准等均不统一,导致所建立动物模型的科学价值低、难于推广应用。此次研究旨在明确不同造模条件对激素性股骨头坏死家兔模型建立的影响,分析模型成功建立的适宜条件。方法:检索中国知网、万方、维普、中国生物医学文献服务系统、Web of Science、PubMed和EMbase数据库中截至2022-04-01前有关激素性股骨头坏死家兔造模的文献,依据纳排标准以及文献质量评价等完成对文献的筛选并提取文献中结局指标数据,运用RevMan、Stata和ADDIS统计软件对纳入数据进行Meta分析。结果:(1)最终纳入82篇文献,共1366只家兔纳入研究,激素性股骨头坏死造模方法分为单纯激素法、激素联合脂多糖法和激素联合血清法3种,其中单纯激素法33篇文献,激素联合脂多糖法20篇文献,激素联合血清法29篇文献;(2)Meta分析结果显示,3种造模方法均能显著增加激素性股骨头坏死家兔股骨头空骨陷窝率(P<0.001),显著降低激素性股骨头坏死家兔股骨头骨小梁面积比(P<0.001);各造模方法的空骨陷窝率排序结果为:激素联合脂多糖法>单纯激素法>激素联合血清法>正常组;骨小梁面积比排序结果:正常组>激素联合血清法>单纯激素法>激素联合脂多糖法;(3)亚组分析结果提示:单纯激素诱导的家兔模型空骨陷窝率可能与家兔品种和造模用激素种类有关(组间差异P<0.05),其中新西兰白兔合并效应量高于中国白兔(P<0.05)和日本白兔,地塞米松合并效应量高于其他激素种类;激素联合脂多糖诱导的模型空骨陷窝率与激素种类和脂多糖给药模式有关(组间差异P<0.05),其中甲泼尼龙琥珀酸钠合并效应量显著高于其他激素种类(P<0.05),泼尼松龙合并效应量显著低于其他激素种类(P<0.05),脂多糖100μg/kg×2次的合并效应量显著低于10μg/kg×2次和50μg/kg×2次(P<0.05);激素联合血清诱导的模型空骨陷窝率与激素种类和血清剂量有关(组间差异P<0.05),其中地塞米松磷酸钠合并效应量显著高于其他激素种类(P<0.05),地塞米松合并效应量显著低于其他激素种类(P<0.05),血清“10 mL/kg+6 mL/kg”组合剂量的合并效应量低于其他血清剂量(P<0.05)。结论:(1)以空骨陷窝率和骨小梁面积比作为模型成功建立的判断标准,3种造模方法都可成功构建家兔激素性股骨头坏死模型,其中激素联合脂多糖法最优;(2)选择单纯激素法时建议使用新西兰白兔和地塞米松,选择激素联合脂多糖法时建议使用甲泼尼龙琥珀酸钠和低剂量脂多糖,选择激素联合血清造模法时建议使用地塞米松磷酸钠。展开更多
目的系统评价基于PLISSIT模式的性干预对女性癌症患者性功能的干预效果。方法计算机检索中国知网、万方数据库、维普数据库、the Cochrane Library、PubMed及Web of Science等数据库或平台中PLISSIT模式的性干预对女性癌症患者性功能影...目的系统评价基于PLISSIT模式的性干预对女性癌症患者性功能的干预效果。方法计算机检索中国知网、万方数据库、维普数据库、the Cochrane Library、PubMed及Web of Science等数据库或平台中PLISSIT模式的性干预对女性癌症患者性功能影响的文献,检索时限为1974年至2022年12月30日。使用RevMan 5.3软件进行统计分析。结果共纳入8篇文献,共413例研究对象。Meta分析结果显示,与常规康复指导相比,PLISSIT干预能提高患者的性功能(MD=5.25,95%CI:3.14~7.36,P<0.001),改善女性癌症患者的性生活质量(MD=14.07,95%CI:11.31~16.84,P<0.001)。结论基于PLISSIT模式的性干预能够提高女性癌症患者的性功能,改善其性生活质量。展开更多
Engineering data are separately organized and their schemas are increasingly complex and variable. Engineering data management systems are needed to be able to manage the unified data and to be both customizable and e...Engineering data are separately organized and their schemas are increasingly complex and variable. Engineering data management systems are needed to be able to manage the unified data and to be both customizable and extensible. The design of the systems is heavily dependent on the flexibility and self-description of the data model. The characteristics of engineering data and their management facts are analyzed. Then engineering data warehouse (EDW) architecture and multi-layer metamodels are presented. Also an approach to manage anduse engineering data by a meta object is proposed. Finally, an application flight test EDW system (FTEDWS) is described and meta-objects to manage engineering data in the data warehouse are used. It shows that adopting a meta-modeling approach provides a support for interchangeability and a sufficiently flexible environment in which the system evolution and the reusability can be handled.展开更多
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
To investigate the application of meta-model for finite element( FE) model updating of structures,the performance of two popular meta-model,i. e.,Kriging model and response surface model( RSM),were compared in detail....To investigate the application of meta-model for finite element( FE) model updating of structures,the performance of two popular meta-model,i. e.,Kriging model and response surface model( RSM),were compared in detail. Firstly,above two kinds of meta-model were introduced briefly. Secondly,some key issues of the application of meta-model to FE model updating of structures were proposed and discussed,and then some advices were presented in order to select a reasonable meta-model for the purpose of updating the FE model of structures. Finally,the procedure of FE model updating based on meta-model was implemented by updating the FE model of a truss bridge model with the measured modal parameters. The results showed that the Kriging model was more proper for FE model updating of complex structures.展开更多
In this study, a new method for conversion of solid finite element solution to beam finite element solution is developed based on the meta-modeling theory which constructs a model consistent with continuum mechanics. ...In this study, a new method for conversion of solid finite element solution to beam finite element solution is developed based on the meta-modeling theory which constructs a model consistent with continuum mechanics. The proposed method is rigorous and efficient compared to a typical conversion method which merely computes surface integration of solid element nodal stresses to obtain cross-sectional forces. The meta-modeling theory ensures the rigorousness of proposed method by defining a proper distance between beam element and solid element solutions in a function space of continuum mechanics. Results of numerical verification test that is conducted with a simple cantilever beam are used to find the proper distance function for this conversion. Time history analysis of the main tunnel structure of a real ramp tunnel is considered as a numerical example for the proposed conversion method. It is shown that cross-sectional forces are readily computed for solid element solution of the main tunnel structure when it is converted to a beam element solution using the proposed method. Further, envelopes of resultant forces which are of primary importance for the purpose of design, are developed for a given ground motion at the end.展开更多
文摘Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and build a workflow meta model supporting ABC. Firstly, the concept and concept model of activity based costing (ABC) are introduced. Next, the meta model of P -PROCE (Process, Product, Resource, Organization, and Cost & Evaluation) is presented. Then the cost meta model is defined by adding ABC to P -PROCE model. Object constraint language (OCL) is used to express meta model and constraints. Finally, we show an enterprise modeling and simulation tool based on the workflow meta model. We can systematically construct an enterprise model and easily and efficiently conduct simulation. Moreover it enables us to analyze and evaluate business processes and its costs.
基金Researchers Supporting Project Number(RSPD2024R 553),King Saud University,Riyadh,Saudi Arabia.
文摘Wheat is a critical crop,extensively consumed worldwide,and its production enhancement is essential to meet escalating demand.The presence of diseases like stem rust,leaf rust,yellow rust,and tan spot significantly diminishes wheat yield,making the early and precise identification of these diseases vital for effective disease management.With advancements in deep learning algorithms,researchers have proposed many methods for the automated detection of disease pathogens;however,accurately detectingmultiple disease pathogens simultaneously remains a challenge.This challenge arises due to the scarcity of RGB images for multiple diseases,class imbalance in existing public datasets,and the difficulty in extracting features that discriminate between multiple classes of disease pathogens.In this research,a novel method is proposed based on Transfer Generative Adversarial Networks for augmenting existing data,thereby overcoming the problems of class imbalance and data scarcity.This study proposes a customized architecture of Vision Transformers(ViT),where the feature vector is obtained by concatenating features extracted from the custom ViT and Graph Neural Networks.This paper also proposes a Model AgnosticMeta Learning(MAML)based ensemble classifier for accurate classification.The proposedmodel,validated on public datasets for wheat disease pathogen classification,achieved a test accuracy of 99.20%and an F1-score of 97.95%.Compared with existing state-of-the-art methods,this proposed model outperforms in terms of accuracy,F1-score,and the number of disease pathogens detection.In future,more diseases can be included for detection along with some other modalities like pests and weed.
文摘目的基于贝叶斯网状Meta分析(Bayesian Network Meta-analysis,BNMA)方法,评价临床常用的口服或鼻饲中成药治疗脑出血(Intracerebral haemorrhage,ICH)术后的有效性及安全性。方法检索中国知网(CNKI)、万方数据知识服务平台(Wanfang)、维普中文期刊(VIP)、中国生物医学文献服务系统(SinoMed)、PubMed、Embase、Cochrane Library、Web of Science建库至2023年8月25日有关中成药干预ICH术后的随机对照试验(randomized controlled trial,RCT);使用ROB 2.0进行偏倚风险评估,运用R 4.2.2加载BUGSnet 1.1.0程序包进行BNMA。结果共纳入28项RCT,总样本量2530例,涵盖9种口服中成药[安宫牛黄丸(AGNH)、苏合香丸(SHX)、脑血疏口服液(NXS)、脑心通胶囊(NXT)、脑血康片(NXK)、消瘀康胶囊(XYK)、养血清脑颗粒(YXQN)、通天口服液(TT)、三七通舒胶囊(SQTS)],所有患者均行手术治疗和术后常规西医治疗(conventional western medicine treatment,CWMT),试验组加用口服或鼻饲中成药。BNMA结果显示,AGNH+CWMT组在降低短期病死率、美国国立卫生研究院卒中量表评分(National Institute of Health stroke scale,NIHSS)和脑血肿周围水肿量方面排第1位,与CWMT组比较P<0.05;SHX+CWMT组在提高总有效率方面排第1位,与CWMT组比较P<0.05;TT+CWMT组在增加格拉斯哥昏迷评分(Glasgow Coma Scale,GCS)方面排第1位,与CWMT组比较P<0.05;YXQN+CWMT组在提高巴塞尔指数(Barthel index,BI)方面排第1位,与CWMT组比较P<0.05;NXS+CWMT组在促进脑血肿吸收量方面排第1位,与CWMT组比较P>0.05;NXT+CWMT组在缩短平均住院时间方面排第1位,与CWMT组比较P>0.05。结论与CWMT组比较,脑出血术后患者在CWMT基础上联用中成药治疗在提高总有效率,降低病死率、NIHSS评分,提高GCS评分、BI指数方面疗效确切,但在促进血肿吸收和缩短平均住院时间方面差异无统计学意义。AGNH综合疗效较好,可能为治疗ICH术后综合疗效最优的中成药。但由于纳入研究质量和方法学的局限性,所得结论仍需进一步验证。
文摘目的:激素性股骨头坏死家兔模型是最常用的股骨头坏死动物模型,其股骨头病理学改变与临床较为接近,但目前国内外报道的造模条件、方法和评价标准等均不统一,导致所建立动物模型的科学价值低、难于推广应用。此次研究旨在明确不同造模条件对激素性股骨头坏死家兔模型建立的影响,分析模型成功建立的适宜条件。方法:检索中国知网、万方、维普、中国生物医学文献服务系统、Web of Science、PubMed和EMbase数据库中截至2022-04-01前有关激素性股骨头坏死家兔造模的文献,依据纳排标准以及文献质量评价等完成对文献的筛选并提取文献中结局指标数据,运用RevMan、Stata和ADDIS统计软件对纳入数据进行Meta分析。结果:(1)最终纳入82篇文献,共1366只家兔纳入研究,激素性股骨头坏死造模方法分为单纯激素法、激素联合脂多糖法和激素联合血清法3种,其中单纯激素法33篇文献,激素联合脂多糖法20篇文献,激素联合血清法29篇文献;(2)Meta分析结果显示,3种造模方法均能显著增加激素性股骨头坏死家兔股骨头空骨陷窝率(P<0.001),显著降低激素性股骨头坏死家兔股骨头骨小梁面积比(P<0.001);各造模方法的空骨陷窝率排序结果为:激素联合脂多糖法>单纯激素法>激素联合血清法>正常组;骨小梁面积比排序结果:正常组>激素联合血清法>单纯激素法>激素联合脂多糖法;(3)亚组分析结果提示:单纯激素诱导的家兔模型空骨陷窝率可能与家兔品种和造模用激素种类有关(组间差异P<0.05),其中新西兰白兔合并效应量高于中国白兔(P<0.05)和日本白兔,地塞米松合并效应量高于其他激素种类;激素联合脂多糖诱导的模型空骨陷窝率与激素种类和脂多糖给药模式有关(组间差异P<0.05),其中甲泼尼龙琥珀酸钠合并效应量显著高于其他激素种类(P<0.05),泼尼松龙合并效应量显著低于其他激素种类(P<0.05),脂多糖100μg/kg×2次的合并效应量显著低于10μg/kg×2次和50μg/kg×2次(P<0.05);激素联合血清诱导的模型空骨陷窝率与激素种类和血清剂量有关(组间差异P<0.05),其中地塞米松磷酸钠合并效应量显著高于其他激素种类(P<0.05),地塞米松合并效应量显著低于其他激素种类(P<0.05),血清“10 mL/kg+6 mL/kg”组合剂量的合并效应量低于其他血清剂量(P<0.05)。结论:(1)以空骨陷窝率和骨小梁面积比作为模型成功建立的判断标准,3种造模方法都可成功构建家兔激素性股骨头坏死模型,其中激素联合脂多糖法最优;(2)选择单纯激素法时建议使用新西兰白兔和地塞米松,选择激素联合脂多糖法时建议使用甲泼尼龙琥珀酸钠和低剂量脂多糖,选择激素联合血清造模法时建议使用地塞米松磷酸钠。
文摘Engineering data are separately organized and their schemas are increasingly complex and variable. Engineering data management systems are needed to be able to manage the unified data and to be both customizable and extensible. The design of the systems is heavily dependent on the flexibility and self-description of the data model. The characteristics of engineering data and their management facts are analyzed. Then engineering data warehouse (EDW) architecture and multi-layer metamodels are presented. Also an approach to manage anduse engineering data by a meta object is proposed. Finally, an application flight test EDW system (FTEDWS) is described and meta-objects to manage engineering data in the data warehouse are used. It shows that adopting a meta-modeling approach provides a support for interchangeability and a sufficiently flexible environment in which the system evolution and the reusability can be handled.
基金supported by the National Natural Science Foundation of China (Grant No. 41271003)the National Basic Research Program of China (Grants No. 2010CB428403 and 2010CB951103)
文摘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.
基金Sponsored by the National Key Technology Research and Development Program of China(Grant No.2011BAK02B02)
文摘To investigate the application of meta-model for finite element( FE) model updating of structures,the performance of two popular meta-model,i. e.,Kriging model and response surface model( RSM),were compared in detail. Firstly,above two kinds of meta-model were introduced briefly. Secondly,some key issues of the application of meta-model to FE model updating of structures were proposed and discussed,and then some advices were presented in order to select a reasonable meta-model for the purpose of updating the FE model of structures. Finally,the procedure of FE model updating based on meta-model was implemented by updating the FE model of a truss bridge model with the measured modal parameters. The results showed that the Kriging model was more proper for FE model updating of complex structures.
文摘In this study, a new method for conversion of solid finite element solution to beam finite element solution is developed based on the meta-modeling theory which constructs a model consistent with continuum mechanics. The proposed method is rigorous and efficient compared to a typical conversion method which merely computes surface integration of solid element nodal stresses to obtain cross-sectional forces. The meta-modeling theory ensures the rigorousness of proposed method by defining a proper distance between beam element and solid element solutions in a function space of continuum mechanics. Results of numerical verification test that is conducted with a simple cantilever beam are used to find the proper distance function for this conversion. Time history analysis of the main tunnel structure of a real ramp tunnel is considered as a numerical example for the proposed conversion method. It is shown that cross-sectional forces are readily computed for solid element solution of the main tunnel structure when it is converted to a beam element solution using the proposed method. Further, envelopes of resultant forces which are of primary importance for the purpose of design, are developed for a given ground motion at the end.
