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Operating mechanism and set pair analysis model of a sustainable water resources system

Chaoyang DU,Jingjie YU,Huaping ZHONG,Dandan WANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 288-297 doi: 10.1007/s11783-014-0642-4

摘要： There is no alternative 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.

关键词： sustainable water resources system     operating mechanism     set pair analysis model     Shanghai    

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Multi-scale evaluation of river health in Liao River Basin, China

Fei XU, Yanwei ZHAO, Zhifeng YANG, Yuan ZHANG

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 227-235 doi: 10.1007/s11783-010-0219-9

摘要： Previous studies on river health evaluation mainly focused on characterizations at a river-corridor scale and ignored the complex interactions between the river ecosystem and other components of the river basin. Based on the consideration of the interactions among rivers, associated river basin and habitats, an assessment framework with multi-scale indicators was developed. An index system divided among these three scales to characterize the health of river ecosystems in China’s Liao River Basin was established. Set pair analysis was applied to integrate the multi-scale indicators and determine the health classes. The evaluation results indicated that the rivers in the western and eastern zones of the Liao River were classified as sick, and rivers in the main stream of the Liao and Huntai rivers were classified as unhealthy. An excessive level of disturbances, such as large pollution loads and dense construction of water conservation projects within the river basin, were the main causes of the river health deterioration.

关键词： multi-scale characterization     river health evaluation     Liao River Basin     set pair analysis    

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Level set-based isogeometric topology optimization for maximizing fundamental eigenfrequency

Manman XU, Shuting WANG, Xianda XIE

《机械工程前沿（英文）》 2019年 第14卷 第2期   页码 222-234 doi: 10.1007/s11465-019-0534-1

摘要： Maximizing the fundamental eigenfrequency is an efficient means for vibrating structures to avoid resonance and noises. In this study, we develop an isogeometric analysis (IGA)-based level set model for the formulation and solution of topology optimization in cases with maximum eigenfrequency. The proposed method is based on a combination of level set method and IGA technique, which uses the non-uniform rational B-spline (NURBS), description of geometry, to perform analysis. The same NURBS is used for geometry representation, but also for IGA-based dynamic analysis and parameterization of the level set surface, that is, the level set function. The method is applied to topology optimization problems of maximizing the fundamental eigenfrequency for a given amount of material. A modal track method, that monitors a single target eigenmode is employed to prevent the exchange of eigenmode order number in eigenfrequency optimization. The validity and efficiency of the proposed method are illustrated by benchmark examples.

关键词： topology optimization     level set method     isogeometric analysis     eigenfrequency    

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Characteristics of plankton Hg bioaccumulations based on a global data set and the implications for aquatic

《环境科学与工程前沿（英文）》 2022年 第16卷 第3期 doi: 10.1007/s11783-021-1471-x

摘要：

• Hg bioaccumulation by phytoplankton varies among aquatic ecosystems.

关键词： Plankton     Hg bioaccumulation     Physiological characteristics     A cross-system analysis     Nutrient compositions     Global data set    

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Application of random set method in a deep excavation: based on a case study in Tehran cemented alluvium

Arash SEKHAVATIAN, Asskar Janalizadeh CHOOBBASTI

《结构与土木工程前沿（英文）》 2019年 第13卷 第1期   页码 66-80 doi: 10.1007/s11709-018-0461-y

摘要： The design of high-rise buildings often necessitates ground excavation, where buildings are in close proximity to the construction, thus there is a potential for damage to these structures. This paper studies an efficient user-friendly framework for dealing with uncertainties in a deep excavation in layers of cemented coarse grained soil located in Tehran, Iran by non-deterministic Random Set (RS) method. In order to enhance the acceptability of the method among engineers, a pertinent code was written in FISH language of FLAC2D software which enables the designers to run all simulations simultaneously, without cumbersome procedure of changing input variables in every individual analysis. This could drastically decrease the computational effort and cost imposed to the project, which is of great importance especially to the owners. The results are presented in terms of probability of occurrence and most likely values of the horizontal displacement at top of the wall at every stage of construction. Moreover, a methodology for assessing the credibility of the uncertainty model is presented using a quality indicator. It was concluded that performing RS analysis before the beginning of every stage could cause great economical savings, while improving the safety of the project.

关键词： uncertainty     reliability analysis     deep excavations     random set method     finite difference method    

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Isogeometric analysis based on geometric reconstruction models

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 782-797 doi: 10.1007/s11465-021-0648-0

摘要： In isogeometric analysis (IGA), the boundary representation of computer-aided design (CAD) and the tensor-product non-uniform rational B-spline structure make the analysis of three-dimensional (3D) problems with irregular geometries difficult. In this paper, an IGA method for complex models is presented by reconstructing analysis-suitable models. The CAD model is represented by boundary polygons or point cloud and is embedded into a regular background grid, and a model reconstruction method is proposed to obtain the level set function of the approximate model, which can be directly used in IGA. Three 3D examples are used to test the proposed method, and the results demonstrate that the proposed method can deal with complex engineering parts reconstructed by boundary polygons or point clouds.

关键词： isogeometric analysis     reconstruction model     level set function     trimmed element     point cloud    

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Geometrically constrained isogeometric parameterized level-set based topology optimization via trimmed

Yingjun WANG,David J. BENSON

《机械工程前沿（英文）》 2016年 第11卷 第4期   页码 328-343 doi: 10.1007/s11465-016-0403-0

摘要：

In this paper, an approach based on the fast point-in-polygon (PIP) algorithm and trimmed elements is proposed for isogeometric topology optimization (TO) with arbitrary geometric constraints. The isogeometric parameterized level-set-based TO method, which directly uses the non-uniform rational basis splines (NURBS) for both level set function (LSF) parameterization and objective function calculation, provides higher accuracy and efficiency than previous methods. The integration of trimmed elements is completed by the efficient quadrature rule that can design the quadrature points and weights for arbitrary geometric shape. Numerical examples demonstrate the efficiency and flexibility of the method.

关键词： isogeometric analysis     topology optimization     level set method     arbitrary geometric constraint     trimmed element    

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Reliability assessment of three-dimensional bearing capacity of shallow foundation using fuzzy set theory

Rajarshi PRAMANIK, Dilip Kumar BAIDYA, Nirjhar DHANG

《结构与土木工程前沿（英文）》 2021年 第15卷 第2期   页码 478-489 doi: 10.1007/s11709-021-0698-8

摘要： The aim of this study is to investigate the applicability of reliability theory on surface square/rectangular footing against bearing capacity failure using fuzzy set theory in conjunction with the finite element method. Soil is modeled as a three-dimensional spatially varying medium, where its parameters (cohesion, friction angle, unit weight, etc.) are considered as fuzzy variables that maintain some membership functions. Soil is idealized as an elastic-perfectly plastic material obeying the Mohr–Coulomb failure criterion, where both associated and non-associated flow rules are considered in estimating the ultimate bearing capacity of the footing. The spatial variability of the soil is incorporated for both isotropic and anisotropic fields, which are determined by the values of scales of fluctuation in both the horizontal and vertical directions. A new parameter namely, limiting applied pressure at zero failure probability is proposed, and it indirectly predicts the failure probability of the footing. The effect of the coefficient of variation of the friction angle of the soil on the probability of failure is analyzed, and it is observed that the effect is significant. Furthermore, the effect of the scale of fluctuation on the probability of failure is investigated, and the necessity for considering spatial variability in the reliability analysis is well proven.

关键词： finite element method     square footing     reliability analysis     fuzzy set theory     coefficient of variation     spatial variability    

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Sensitivity analysis of torsional vibration behavior of the shafting of a turbo generator set to changes

XIE Danmei, ZHANG Hengliang, DONG Chuan, LIU Zhanhui, YANG Changzhu

《能源前沿（英文）》 2007年 第1卷 第4期   页码 483-486 doi: 10.1007/s11708-007-0072-4

摘要： Aiming at a 300 MW turbo-generator model, the sensitivity of natural torsional frequencies and modes of torsional vibration (TV) to the rotational inertia and stiffness of the turbo-generator were analyzed. Calculation results show

关键词： Calculation     MW turbo-generator     sensitivity     stiffness    

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An enhanced environmental multimedia modeling system based on fuzzy-set approach: II.

Rongrong ZHANG,Chesheng ZHAN,Xiaomeng SONG,Baolin LIU

《环境科学与工程前沿（英文）》 2015年 第9卷 第6期   页码 1025-1035 doi: 10.1007/s11783-014-0655-z

摘要： Part I of this study develops an enhanced environmental multimedia modeling system (EMMS) based on fuzzy-set approach. Once the model development is complete, the composite module and the entire modeling system need to be tested and validated to ensure that the model can simulate natural phenomena with reasonable and reliable accuracy. The developed EMMS is first tested in a complete case study. And then verification results are conducted to compare with extensively researched literature data. In the third step, the data from an experimental landfill site is used for a pilot-scale validation. The comparisons between EMMS outputs and the literature data indicate that the EMMS can perform accurate modeling simulation. The modules of EMMS could support the entire environmental multimedia modeling system. Further field-scale validation is finished. The results are satisfactory. Most of the modeling yields closely match the monitoring data collected from sites. In addition, with the aid of fuzzy-set approach, EMMS can be a reliable and powerful tool to address the complex environmental multimedia pollution problems and provide an extensive support for decision makers in managing the contaminated environmental systems.

关键词： environmental multimedia modelling system     fuzzy-set approach     application     model validation     uncertainty analysis    

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Adaptive robust beamformer formulti-pair two-way relay networks with imperfect channel state information

Jin WANG,Feng SHU,Ri-qing CHEN,Yu-di CUI,Yu CHEN,Jun LI

《信息与电子工程前沿（英文）》 2016年 第17卷 第3期   页码 265-280 doi: 10.1631/FITEE.1500134

摘要： In wideband multi-pair two-way relay networks, the performance of beamforming at a relay station (RS) is intimately related to the accuracy of the channel state information (CSI) available. The accuracy of CSI is determined by Doppler spread, delay between beamforming and channel estimation, and density of pilot symbols, including transmit power of pilot symbols. The coefficient of the Gaussian-Markov CSI error model is modeled as a function of CSI delay, Doppler spread, and signal-to-noise ratio, and can be estimated in real time. In accordance with the real-time estimated coefficients of the error model, an adaptive robust maximum signal-to-interferenceand- noise ratio (Max-SINR) plus maximum signal-to-leakage-and-noise ratio (Max-SLNR) beamformer at an RS is proposed to track the variation of the CSI error. From simulation results and analysis, it is shown that: compared to existing non-adaptive beamformers, the proposed adaptive beamformer is more robust and performs much better in the sense of bit error rate (BER); with increase in the density of transmit pilot symbols, its BER and sum-rate performances tend to those of the beamformer of Max-SINR plus Max-SLNR with ideal CSI.

关键词： Multi-pair two-way relay     Adaptive robust beamformer     Channel state information (CSI)     Maximum signal-to-interference-and-noise ratio (Max-SINR)     Maximum signal-to-leakage-and-noise ratio (Max-SLNR)    

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Fast determination of tobramycin by reversed-phase ion-pair high performance liquid chromatography with

Liang ZHU, Jingkang WANG

《化学科学与工程前沿（英文）》 2013年 第7卷 第3期   页码 322-328 doi: 10.1007/s11705-013-1348-z

摘要： A simple and direct method without a derivation step for routine analysis of tobramycin has been developed. This method used reversed-phase ion-pair high performance liquid chromatography (HPLC) with a refractive index (RI) detector and a C18 column which is stable at pH above 1.00. The presence of 4.50 mg·mL trifluoroacetic acid (TFA) in the mobile phase improved the protonation of tobramycin and the formation of ion-pairs, and thus reduced its hydrophility. This unique separation–detection combination showed good linearity with correlation coefficients 0.9996 in the concentration range of 0.25–2.50 mg·mL . The quantitation limit and detection limit were determined to be 0.23 mg·mL and 0.071 mg·mL , respectively. Tobramycin was recovered in 98.00%, 98.84% and 99.64% for tobramycin solutions at concentrations of 2.25 mg·mL , 1.50 mg·mL and 0.75 mg·mL , respectively. The relative standard deviations for six spiked samples ranged from 0.20% to 2.40%, indicating a good reproducibility of this method.

关键词： tobramycin     aminoglycoside     refractive index detector     high-performance liquid chromatography     ion-pairing    

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Level set band method: A combination of density-based and level set methods for the topology optimization

Peng WEI, Wenwen WANG, Yang YANG, Michael Yu WANG

《机械工程前沿（英文）》 2020年 第15卷 第3期   页码 390-405 doi: 10.1007/s11465-020-0588-0

摘要： The level set method (LSM), which is transplanted from the computer graphics field, has been successfully introduced into the structural topology optimization field for about two decades, but it still has not been widely applied to practical engineering problems as density-based methods do. One of the reasons is that it acts as a boundary evolution algorithm, which is not as flexible as density-based methods at controlling topology changes. In this study, a level set band method is proposed to overcome this drawback in handling topology changes in the level set framework. This scheme is proposed to improve the continuity of objective and constraint functions by incorporating one parameter, namely, level set band, to seamlessly combine LSM and density-based method to utilize their advantages. The proposed method demonstrates a flexible topology change by applying a certain size of the level set band and can converge to a clear boundary representation methodology. The method is easy to implement for improving existing LSMs and does not require the introduction of penalization or filtering factors that are prone to numerical issues. Several 2D and 3D numerical examples of compliance minimization problems are studied to illustrate the effects of the proposed method.

关键词： level set method     topology optimization     density-based method     level set band    

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Maximum independent set in planning freight railway transportation

Gainanov Damir N., Mladenovic NENAD, Rasskazova V. A.

《工程管理前沿（英文）》 2018年 第5卷 第4期   页码 499-506 doi: 10.15302/J-FEM-2018031

摘要：

This work is devoted to the problem of planning of freight railway transportation. We define a special conflict graph on the basis of a set of acceptable train routes. The investigation aims to solve the classical combinatorial optimization problem in relation to the maximum independent set of vertices in undirected graphs. The level representation of the graph and its tree are introduced. With use of these constructions, the lower and upper bounds for the number of vertices in the maximum independent set are obtained.

关键词： independent set     algorithm     planning of transportation     two-sided estimate    

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Analysis of energy saving optimization of campus buildings based on energy simulation

Dingding TONG, Jing ZHAO

《能源前沿（英文）》 2013年 第7卷 第3期   页码 388-398 doi: 10.1007/s11708-013-0273-7

摘要： The energy consumption of campus buildings has specific characteristics, because of the concentrated distribution of people’s working time and locations that change in line with distinct seasonal features. The traditional energy system design and operation for campus buildings is only based on the constant room temperature, such as 25°C in summer and 18°C in winter in China, not taking into consideration the real heating or cooling load characteristics of campus buildings with different functions during the whole day and whole year, which usually results in a lot of energy waste. This paper proposes to set different set-point temperatures in different operation stages of public and residential campus buildings to reduce the heating and cooling design load for energy station and total campus energy consumption for annual operation. Taking a campus under construction in Tianjin, China as an example, two kinds of single building models were established as the typical public building and residential building models on the campus. Besides, the models were simulated at both set-point room temperature and constant room temperature respectively. The comparison of the simulation results showed that the single building energy saving method of the peak load clipping could be used for further analysis of the annual energy consumption of campus building groups. The results proved that the strategy of set-point temperature optimization could efficiently reduce the design load and energy consumption of campus building groups.

关键词： campus buildings     set-point temperature     energy simulation     energy saving optimization    

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标题 作者 时间 类型 操作

Operating mechanism and set pair analysis model of a sustainable water resources system

Chaoyang DU,Jingjie YU,Huaping ZHONG,Dandan WANG

期刊论文

Multi-scale evaluation of river health in Liao River Basin, China

Fei XU, Yanwei ZHAO, Zhifeng YANG, Yuan ZHANG

期刊论文

Level set-based isogeometric topology optimization for maximizing fundamental eigenfrequency

Manman XU, Shuting WANG, Xianda XIE

期刊论文

Characteristics of plankton Hg bioaccumulations based on a global data set and the implications for aquatic

期刊论文

Application of random set method in a deep excavation: based on a case study in Tehran cemented alluvium

Arash SEKHAVATIAN, Asskar Janalizadeh CHOOBBASTI

期刊论文

Isogeometric analysis based on geometric reconstruction models

期刊论文

Geometrically constrained isogeometric parameterized level-set based topology optimization via trimmed

Yingjun WANG,David J. BENSON

期刊论文

Reliability assessment of three-dimensional bearing capacity of shallow foundation using fuzzy set theory

Rajarshi PRAMANIK, Dilip Kumar BAIDYA, Nirjhar DHANG

期刊论文

Sensitivity analysis of torsional vibration behavior of the shafting of a turbo generator set to changes

XIE Danmei, ZHANG Hengliang, DONG Chuan, LIU Zhanhui, YANG Changzhu

期刊论文

An enhanced environmental multimedia modeling system based on fuzzy-set approach: II.

Rongrong ZHANG,Chesheng ZHAN,Xiaomeng SONG,Baolin LIU

期刊论文

Adaptive robust beamformer formulti-pair two-way relay networks with imperfect channel state information

Jin WANG,Feng SHU,Ri-qing CHEN,Yu-di CUI,Yu CHEN,Jun LI

期刊论文

Fast determination of tobramycin by reversed-phase ion-pair high performance liquid chromatography with

Liang ZHU, Jingkang WANG

期刊论文

Level set band method: A combination of density-based and level set methods for the topology optimization

Peng WEI, Wenwen WANG, Yang YANG, Michael Yu WANG

期刊论文

Maximum independent set in planning freight railway transportation

Gainanov Damir N., Mladenovic NENAD, Rasskazova V. A.

期刊论文

Analysis of energy saving optimization of campus buildings based on energy simulation

Dingding TONG, Jing ZHAO

期刊论文