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Research on port ecological suitability evaluation index system and evaluation model

Yaofeng XIE,Xia LV,Ru LIU,Liuyan MAO,Xiaoxi LIU

《结构与土木工程前沿(英文)》 2015年 第9卷 第1期   页码 65-70 doi: 10.1007/s11709-014-0258-6

摘要: Along with the rapid development of port building, the negative impacts of port’s construction and operation on the coastline ecosystem are also increasingly strong. Therefore, it’s urgent to establish a scientific and complete system of port ecological suitability evaluation. This paper pointed out the characteristics of port ecological effects and the principles of selecting evaluation index, and used the “pressure-state-response (PSR)” model to analysis the various pressures on the environment caused by port construction and operation, and the system’s response. On this basis, we constructed the port ecological suitability evaluation index. This model used the combination of qualitative and quantitative analytic hierarchy process, to meet the multi-level, multi-objective characteristics of evaluation index system. The evaluation index system and evaluation model can be used to analysis the ecological suitability of port projects comprehensively and have some guiding significance to the port ecological suitability evaluation.

关键词: port     ecological suitability     press-state-response (PSR) model     evaluation index system    

PRESS-based EFOR algorithm for the dynamic parametrical modeling of nonlinear MDOF systems

Haopeng LIU, Yunpeng ZHU, Zhong LUO, Qingkai HAN

《机械工程前沿(英文)》 2018年 第13卷 第3期   页码 390-400 doi: 10.1007/s11465-017-0459-5

摘要:

In response to the identification problem concerning multi-degree of freedom (MDOF) nonlinear systems, this study presents the extended forward orthogonal regression (EFOR) based on predicted residual sums of squares (PRESS) to construct a nonlinear dynamic parametrical model. The proposed parametrical model is based on the non-linear autoregressive with exogenous inputs (NARX) model and aims to explicitly reveal the physical design parameters of the system. The PRESS-based EFOR algorithm is proposed to identify such a model for MDOF systems. By using the algorithm, we built a common-structured model based on the fundamental concept of evaluating its generalization capability through cross-validation. The resulting model aims to prevent over-fitting with poor generalization performance caused by the average error reduction ratio (AERR)-based EFOR algorithm. Then, a functional relationship is established between the coefficients of the terms and the design parameters of the unified model. Moreover, a 5-DOF nonlinear system is taken as a case to illustrate the modeling of the proposed algorithm. Finally, a dynamic parametrical model of a cantilever beam is constructed from experimental data. Results indicate that the dynamic parametrical model of nonlinear systems, which depends on the PRESS-based EFOR, can accurately predict the output response, thus providing a theoretical basis for the optimal design of modeling methods for MDOF nonlinear systems.

关键词: MDOF     dynamic parametrical model     NARX model     PRESS-based EFOR     cantilever beam    

Ecological security evaluation of Africa

Huihui WEI, Wenjuan ZHANG, Feng ZHANG, Guojun SUN

《农业科学与工程前沿(英文)》 2020年 第7卷 第4期   页码 467-477 doi: 10.15302/J-FASE-2020320

摘要:

Africa, the second largest continent in the world, has achieved remarkable economic and political results through exploration and positive development. Ecological security comprehensively reflects the heath and integrity of an ecosystem, and it is broadly defined as the security state of a complex artificial ecosystem composed of natural, economic and social factors. Ecological security determines the potential for sustainable development in Africa, especially with its rapidly developing economies. However, there is a lack of information on the ecological security state of the continent as a whole. In this study, we constructed an evaluation system based on a pressure-state-response model and evaluated the ecological security state of all 54 African countries. The results showed that, at the national level, the ecological security state of the countries in Africa differed, as did their spatial and temporal variations from 1995 to 2016. In general, African countries showed relatively good ecological security. The years 2007 and 2001 were the worst and best years, respectively, in terms of ecological security during the study period. At the regional level, North Africa and West Africa had the best and worst ecological security, respectively.

关键词: Africa     ecological security     evaluation system     PSR model    

Development of a constitutive model for rockfills and similar granular materials based on the disturbedstate concept

Mehdi VEISKARAMI, Ali GHORBANI, Mohammadreza ALAVIPOUR

《结构与土木工程前沿(英文)》 2012年 第6卷 第4期   页码 365-378 doi: 10.1007/s11709-012-0178-2

摘要: Behavior of rockfills was investigated experimentally and theoretically. A series of standard triaxial compression tests were carried out on a quarried rockfill material at different stress levels. It was found that both the stress level and the shear stress ratio, like most of granular materials, controls the behavior of rockfill materials. At lower shear stress ratios the behavior is much more similar to a nonlinear elastic solid. When the shear stress goes further, the stress-strain curve shows an elasto-plastic behavior which suggests using the disturbed state concept to develop a constitutive model to predict the stress-strain behavior. The presented constitutive model complies reasonably with the experimental data.

关键词: constitutive model     granular material     rockfill     plasticity     disturbed state concept     stress level    

Computational studies on the seismic response of the State Route 99 bridge in Seattle with SMA/ECC plastic

Jiping GE, M. Saiid SAIIDI, Sebastian VARELA

《结构与土木工程前沿(英文)》 2019年 第13卷 第1期   页码 149-164 doi: 10.1007/s11709-018-0482-6

摘要: This paper reports a computational study on the seismic response of a three-span highway bridge system incorporating conventional and novel substructure details for improved seismic performance. The bridge has three continuous spans supported by two single-column piers and integral abutments founded on drilled shafts. It will be the first full-scale highway bridge to use superelastic shape memory alloy bars (SMA) and engineered cementitious composite (ECC) to mitigate column plastic hinge damage and minimize residual displacements after a strong earthquake. A three-dimensional computational model capturing the nonlinear constitutive response of the novel materials and the effects of dynamic soil-structure interaction was developed to assess the seismic response of the bridge in finite-element software OpenSees. Two versions of the same bridge were analyzed and compared, one with conventional cast-in-place reinforced concrete columns, and the other with top plastic hinges incorporating Nickel-Titanium (NiTi) SMA reinforcing bars and ECC. The novel SMA/ECC plastic hinges were found to substantially reduce damage and post-earthquake residual displacements in the bridge substructure, but led to larger maximum drifts relative to the bridge with conventional reinforced concrete plastic hinges. The analysis results suggested that the novel plastic hinges could lead to improved post-earthquake serviceability of bridges after intense earthquakes.

关键词: seismic design     analytical simulation     near-fault earthquakes     shape memory alloy     engineered cementitious composite     self-centering    

Machine learning and neural network supported state of health simulation and forecasting model for lithium-ion

《能源前沿(英文)》 doi: 10.1007/s11708-023-0891-7

摘要: As the intersection of disciplines deepens, the field of battery modeling is increasingly employing various artificial intelligence (AI) approaches to improve the efficiency of battery management and enhance the stability and reliability of battery operation. This paper reviews the value of AI methods in lithium-ion battery health management and in particular analyses the application of machine learning (ML), one of the many branches of AI, to lithium-ion battery state of health (SOH), focusing on the advantages and strengths of neural network (NN) methods in ML for lithium-ion battery SOH simulation and prediction. NN is one of the important branches of ML, in which the application of NNs such as backpropagation NN, convolutional NN, and long short-term memory NN in SOH estimation of lithium-ion batteries has received wide attention. Reports so far have shown that the utilization of NN to model the SOH of lithium-ion batteries has the advantages of high efficiency, low energy consumption, high robustness, and scalable models. In the future, NN can make a greater contribution to lithium-ion battery management by, first, utilizing more field data to play a more practical role in health feature screening and model building, and second, by enhancing the intelligent screening and combination of battery parameters to characterize the actual lithium-ion battery SOH to a greater extent. The in-depth application of NN in lithium-ion battery SOH will certainly further enhance the science, reliability, stability, and robustness of lithium-ion battery management.

关键词: machine learning     lithium-ion battery     state of health     neural network     artificial intelligence    

An operating state estimation model for integrated energy systems based on distributed solution

Dengji ZHOU, Shixi MA, Dawen HUANG, Huisheng ZHANG, Shilie WENG

《能源前沿(英文)》 2020年 第14卷 第4期   页码 801-816 doi: 10.1007/s11708-020-0687-y

摘要: In view of the disadvantages of the traditional energy supply systems, such as separate planning, separate design, independent operating mode, and the increasingly prominent nonlinear coupling between various sub-systems, the production, transmission, storage and consumption of multiple energy sources are coordinated and optimized by the integrated energy system, which improves energy and infrastructure utilization, promotes renewable energy consumption, and ensures reliability of energy supply. In this paper, the mathematical model of the electricity-gas interconnected integrated energy system and its state estimation method are studied. First, considering the nonlinearity between measurement equations and state variables, a performance simulation model is proposed. Then, the state consistency equations and constraints of the coupling nodes for multiple energy sub-systems are established, and constraints are relaxed into the objective function to decouple the integrated energy system. Finally, a distributed state estimation framework is formed by combining the synchronous alternating direction multiplier method to achieve an efficient estimation of the state of the integrated energy system. A simulation model of an electricity-gas interconnected integrated energy system verifies the efficiency and accuracy of the state estimation method proposed in this paper. The results show that the average relative errors of voltage amplitude and node pressure estimated by the proposed distributed state estimation method are only 0.0132% and 0.0864%, much lower than the estimation error by using the Lagrangian relaxation method. Besides, compared with the centralized estimation method, the proposed distributed method saves 5.42 s of computation time. The proposed method is more accurate and efficient in energy allocation and utilization.

关键词: integrated energy system     state estimation     electricity-gas coupling energy system     nonlinear coupling     distributed solution    

New model of load transfer function for pile analysis based on disturbed state model

LIU Qijian, YANG Linde, WU Jun

《结构与土木工程前沿(英文)》 2007年 第1卷 第4期   页码 443-447 doi: 10.1007/s11709-007-0060-9

摘要: Based on the disturbed state concept (DSC), a new model of load transfer function for pile analysis is established by the idea that the deformed material between pile and soil can be treated as a mixture of two constituent parts, which are in intact or critical state and assumed to obey random distribution. Starting from the homogenization theory of heterogeneous materials and statistics method, a parameter to describe the disturbance degree is proposed, and a formula to determine the parameter has been derived by using the plastic displacement of a pile as distribution variable. In the model, shear intensity of elements in an intact state are simulated by Duncan-Zhang model and that in a critical state by Mohr-Coulomb criterion. The model of this paper has few parameters, which can reflect the aspects of load transfer function, such as hardening, softening and the effects of confining pressure. The well agreement between the in-situ data and the predicted shows that the validity of the model herein. So the proposed model in this paper is easy to be used in engineering practice.

关键词: hardening     homogenization     displacement     engineering     Duncan-Zhang    

Development and application of a random walk model of atmospheric diffusion in the emergency response

CHI Bing, LI Hong, FANG Dong

《能源前沿(英文)》 2007年 第1卷 第2期   页码 195-201 doi: 10.1007/s11708-007-0025-7

摘要: Plume concentration prediction is one of the main contents of radioactive consequence assessment for early emergency response to nuclear accidents. Random characteristics of atmospheric diffusion itself was described, a random walk model of atmospheric diffusion (Random Walk) was introduced and compared with the Lagrangian puff model (RIMPUFF) in the nuclear emergency decision support system (RODOS) developed by the European Community for verification. The results show the concentrations calculated by the two models are quite close except that the plume area calculated by Random Walk is a little smaller than that by RIMPUFF. The random walk model for atmospheric diffusion can simulate the atmospheric diffusion in case of nuclear accidents, and provide more actual information for early emergency and consequence assessment as one of the atmospheric diffusion module of the nuclear emergency decision support system.

关键词: RODOS     concentration prediction     information     nuclear     RIMPUFF    

Enhancement of the polynomial functions response surface model for real-time analyzing ozone sensitivity

Jiangbo Jin, Yun Zhu, Jicheng Jang, Shuxiao Wang, Jia Xing, Pen-Chi Chiang, Shaojia Fan, Shicheng Long

《环境科学与工程前沿(英文)》 2021年 第15卷 第2期 doi: 10.1007/s11783-020-1323-0

摘要: Abstract • The calculation process and algorithm of response surface model (RSM) were enhanced. • The prediction errors of RSM in the margin and transition areas were greatly reduced. • The enhanced RSM was able to analyze O3-NOx-VOC sensitivity in real-time. • The O3 formations were mainly sensitive to VOC, for the two case study regions. Quantification of the nonlinearities between ambient ozone (O3) and the emissions of nitrogen oxides (NOx) and volatile organic compound (VOC) is a prerequisite for an effective O3 control strategy. An Enhanced polynomial functions Response Surface Model (Epf-RSM) with the capability to analyze O3-NOx-VOC sensitivities in real time was developed by integrating the hill-climbing adaptive method into the optimized Extended Response Surface Model (ERSM) system. The Epf-RSM could single out the best suited polynomial function for each grid cell to quantify the responses of O3 concentrations to precursor emission changes. Several comparisons between Epf-RSM and pf-ERSM (polynomial functions based ERSM) were performed using out-of-sample validation, together with comparisons of the spatial distribution and the Empirical Kinetic Modeling Approach diagrams. The comparison results showed that Epf-RSM effectively addressed the drawbacks of pf-ERSM with respect to over-fitting in the margin areas and high biases in the transition areas. The O3 concentrations predicted by Epf-RSM agreed well with Community Multi-scale Air Quality simulation results. The case study results in the Pearl River Delta and the north-western area of the Shandong province indicated that the O3 formations in the central areas of both the regions were more sensitive to anthropogenic VOC in January, April, and October, while more NOx-sensitive in July.

关键词: Response surface model     Hill-climbing algorithm     Ozone pollution     Precursor emissions     Control strategy    

Confining pressure effect on dynamic response of high rockfill dam

Xuexing CAO, Yunlong HE, Kun XIONG,

《结构与土木工程前沿(英文)》 2010年 第4卷 第1期   页码 116-126 doi: 10.1007/s11709-010-0014-5

摘要: Studies show that the dynamic properties of rockfill are strongly dependent on the confining pressure. Therefore, confining pressure effect has become a very important factor in the seismic analysis of high rockfill dam. The relationships of dynamic shear modulus versus dynamic shear strain and damping ratio versus dynamic shear strain had been improved to a certain degree on the basic of widely used Hardin-Drnevich constitutive model in this paper. Then a new model that could consider confining pressure effect has been established. Regression analysis was carried out of the dynamic triaxial experimental data of the damming materials in the Changheba hydropower station of Sichun Province, China. The results show that, the new model can fit the test data well under various confining pressures. A corresponding computational procedure was compiled and applied in the dynamic response analysis of the Changheba Dam. Comparing the calculation results between the new constitutive model and the ordinary Hardin-Drnevich model, it can be seen that the result is conservative to some extent without considering confining pressure effect.

关键词: confining pressure effect     high rockfill dam     dynamic response     Hardin-Drnevich constitutive model    

New response surface model and its applications in aerodynamic optimization of axial compressor blade

LIU Xiaojia, NING Fangfei

《能源前沿(英文)》 2008年 第2卷 第4期   页码 541-549 doi: 10.1007/s11708-008-0077-3

摘要: A parametric method for the axial compressor 2D blade profiles is proposed in which the blade geometries are defined with the parameters commonly used for blade definition, which ensures that the geometric significance is clear and an unreasonable blade profile is not generated. Several illustrations are presented to show the fitting precision of the method. A novel response surface model is proposed which regards the objective distribution function in the vicinity of a sample as normal school, and then generates the response surface function in the whole design space by a linear combination of distribution functions of all the samples. Based on this model, a numerical aerodynamic optimization platform for the axial compressor 2D blade profiles is developed, by which aerodynamic optimization of two compressor blade profiles are presented.

关键词: definition     objective distribution     fitting precision     combination     numerical aerodynamic    

Shallow foundation response variability due to soil and model parameter uncertainty

Prishati RAYCHOWDHURY,Sumit JINDAL

《结构与土木工程前沿(英文)》 2014年 第8卷 第3期   页码 237-251 doi: 10.1007/s11709-014-0242-1

摘要: Geotechnical uncertainties may play crucial role in response prediction of a structure with substantial soil-foundation-structure-interaction (SFSI) effects. Since the behavior of a soil-foundation system may significantly alter the response of the structure supported by it, and consequently several design decisions, it is extremely important to identify and characterize the relevant parameters. Moreover, the modeling approach and the parameters required for the modeling are also critically important for the response prediction. The present work intends to investigate the effect of soil and model parameter uncertainty on the response of shallow foundation-structure systems resting on dry dense sand. The SFSI is modeled using a beam-on-nonlinear-winkler-foundation (BNWF) concept, where soil beneath the foundation is assumed to be an assembly of discrete, nonlinear elements composed of springs, dashpots and gap elements. The sensitivity of both soil and model input parameters on shallow foundation responses are investigated using first-order second-moment (FOSM) analysis and Monte Carlo simulation through Latin hypercube sampling technique. It has been observed that the degree of accuracy in predicting the responses of the shallow foundation is highly sensitive soil parameters, such as friction angle, Poisson’s ratio and shear modulus, rather than model parameters, such as stiffness intensity ratio and spring spacing; indicating the importance of proper characterization of soil parameters for reliable soil-foundation response analysis.

关键词: shallow foun dation     sensitivity analysis     centrifuge data     first-order-second-moment (FOSM) method     parameter uncertainty    

基于状态空间法的铁路建设工程过程质量模型研究

鲁守东,周国华,陈海峰,赵国堂

《中国工程科学》 2014年 第16卷 第3期   页码 64-69

摘要:

在ISO9000过程“输入-输出”模型下,过程质量概念很难得到正确的阐释。从过程的“白箱”理论出发,以铁路建设工程的基本作业单元6M1E为例,给出了过程质量概念的科学涵义及过程质量模型。指出基本作业单元系统的过程包括工艺自然过程、作业过程、管理过程;基本作业单元系统的过程质量取决于3个子过程之间的相互联系和相互作用,同时还受到外界扰动输入因素的影响。最后以现浇预应力砼连续箱梁施工过程为例,阐述了该理论在铁路建设工程质量管理中的具体应用。

关键词: 铁路建设工程     “白箱”模型     状态转移方程     过程质量    

一类基于改进Weibull分布模型的电力电缆寿命评估方法

张铁岩,王承民,孙秋野,张化光

《中国工程科学》 2008年 第10卷 第10期   页码 42-46

摘要:

对电缆的剩余寿命进行评估是电缆寿命管理的关键环节,以往电缆寿命评估的方法中有Arrhenius方法和Weibull分布模型。对这两种方法分别进行分析,特别是确定Arrhenius模型中激活能的计算,以及应用Weibull分布模型对电缆寿命进行评估。最后以实际电缆的状态监测数据,对简化的Arrhenius模型进行仿真,说明所提出的方法是有效的。

关键词: 电缆     寿命评估     Arrhenius模型     Weibull分布    

标题 作者 时间 类型 操作

Research on port ecological suitability evaluation index system and evaluation model

Yaofeng XIE,Xia LV,Ru LIU,Liuyan MAO,Xiaoxi LIU

期刊论文

PRESS-based EFOR algorithm for the dynamic parametrical modeling of nonlinear MDOF systems

Haopeng LIU, Yunpeng ZHU, Zhong LUO, Qingkai HAN

期刊论文

Ecological security evaluation of Africa

Huihui WEI, Wenjuan ZHANG, Feng ZHANG, Guojun SUN

期刊论文

Development of a constitutive model for rockfills and similar granular materials based on the disturbedstate concept

Mehdi VEISKARAMI, Ali GHORBANI, Mohammadreza ALAVIPOUR

期刊论文

Computational studies on the seismic response of the State Route 99 bridge in Seattle with SMA/ECC plastic

Jiping GE, M. Saiid SAIIDI, Sebastian VARELA

期刊论文

Machine learning and neural network supported state of health simulation and forecasting model for lithium-ion

期刊论文

An operating state estimation model for integrated energy systems based on distributed solution

Dengji ZHOU, Shixi MA, Dawen HUANG, Huisheng ZHANG, Shilie WENG

期刊论文

New model of load transfer function for pile analysis based on disturbed state model

LIU Qijian, YANG Linde, WU Jun

期刊论文

Development and application of a random walk model of atmospheric diffusion in the emergency response

CHI Bing, LI Hong, FANG Dong

期刊论文

Enhancement of the polynomial functions response surface model for real-time analyzing ozone sensitivity

Jiangbo Jin, Yun Zhu, Jicheng Jang, Shuxiao Wang, Jia Xing, Pen-Chi Chiang, Shaojia Fan, Shicheng Long

期刊论文

Confining pressure effect on dynamic response of high rockfill dam

Xuexing CAO, Yunlong HE, Kun XIONG,

期刊论文

New response surface model and its applications in aerodynamic optimization of axial compressor blade

LIU Xiaojia, NING Fangfei

期刊论文

Shallow foundation response variability due to soil and model parameter uncertainty

Prishati RAYCHOWDHURY,Sumit JINDAL

期刊论文

基于状态空间法的铁路建设工程过程质量模型研究

鲁守东,周国华,陈海峰,赵国堂

期刊论文

一类基于改进Weibull分布模型的电力电缆寿命评估方法

张铁岩,王承民,孙秋野,张化光

期刊论文