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The impacts of economic restructuring and technology upgrade on air quality and human health in Beijing-Tianjin-Hebei region in China

Chao Liu, Hancheng Dai, Lin Zhang, Changchun Feng

《环境科学与工程前沿(英文)》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1155-y

摘要: Impacts of industrial restructuring and upgrade on air quality & health are assessed. An integrated approach combining different models is used for the assessment. Industrial technology upgrading is more effective than economic restructuring. Ozone is much more difficult to mitigate than PM2.5. In this study, we have analyzed possible policy options to improve the air quality in an industrialized region—Beijing, Tianjin and Hebei (BTH) in China. A comprehensive model framework integrating GAINS-China, GEOS-Chem, and IMED/HEL is established to investigate the impacts of various policies on air pollution and health effects. The model establishes a data interface between economic input/output data and the emission inventory of atmospheric pollutants in the BTH region. Based on in-depth analyses of pollutant emission standards, industrial structure, pollution-intensive industries, and emission intensities in BTH and Pearl River Delta, several scenarios are constructed to explore the effectiveness of policy pathways in improving air quality in the BTH region. These scenarios include two categories: the category of “Industrial Technology Upgrade Policy” scenarios that focuses on reducing the emission intensity of industries vs. that of “Industrial Structure Adjustment Policy” scenarios that focuses on adjusting the proportion of industrial value-added. Our results show that the policy path of industrial technology upgrading can be effective and feasible, while economic structure adjustment shows complex and mixed effectiveness. We also find that the proposed policies and measures will be efficient to reduce pollution of primary pollutants and fine particles, but may not effectively mitigate ambient ozone pollution. Ozone pollution is projected to become increasingly severe in BTH, placing a challenge to pollution mitigation strategies that requires further adjustments to address it.

关键词: Economic restructuring     Cleaner production     Ambient air pollution     Health benefits     IMED model    

Standard model of knowledge representation

Wensheng YIN

《机械工程前沿(英文)》 2016年 第11卷 第3期   页码 275-288 doi: 10.1007/s11465-016-0372-3

摘要:

Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

关键词: knowledge representation     standard model     ontology     system theory     control theory     multidimensional representation    

受限空间火灾模型研究进展

郑昕,袁宏永

《中国工程科学》 2004年 第6卷 第3期   页码 68-74

摘要:

火灾模型是从工程科学的角度出发,分析研究火灾的发生、发展,烟气蔓延以及火灾对周围环境诸如建筑设备、森林植被及大气环境等影响的数学模型。介绍了广泛应用于建筑物内部受限空间的场、区域、网模型以及经验模型的理论思想与数学方程,分析了4种模型在相应环境下应用的合理性,并对火灾模型的发展做出了展望。

关键词: 受限空间     场模型     区域模型     网模型     场区网模型     经验模型    

Elevated temperature creep model of parallel wire strands

《结构与土木工程前沿(英文)》   页码 1060-1071 doi: 10.1007/s11709-023-0981-y

摘要: Parallel wire strands (PWSs), which are widely used in prestressed steel structures, are typically in high-stress states. Under fire conditions, significant creep effects occur, reducing the prestress and influencing the mechanical behavior of PWSs. As there is no existing approach to analyze their creep behavior, this study experimentally investigated the elevated temperature creep model of PWSs. A charge-coupled camera system was incorporated to accurately obtain the deformation of the specimen during the elevated temperature creep test. It was concluded that the temperature level had a more significant effect on the creep strain than the stress level, and 450 °C was the key segment point where the creep rate varied significantly. By comparing the elevated temperature creep test results for PWSs and steel strands, it was found that the creep strain of PWSs was lower than that of steel strands at the same temperature and stress levels. The parameters in the general empirical formula, the Bailey–Norton model, and the composite time-hardening model were fitted based on the experimental results. By evaluating the accuracy and form of the models, the composite time-hardening model, which can simultaneously consider temperature, stress, and time, is recommended for use in the fire-resistance design of pre-tensioned structures with PWSs.

关键词: parallel wire strands     experimental study     elevated temperature creep model    

Test-driven verification/validation of model transformations

László LENGYEL,Hassan CHARAF

《信息与电子工程前沿(英文)》 2015年 第16卷 第2期   页码 85-97 doi: 10.1631/FITEE.1400111

摘要: Why is it important to verify/validate model transformations? The motivation is to improve the quality of the transformations, and therefore the quality of the generated software artifacts. Verified/validated model transformations make it possible to ensure certain properties of the generated software artifacts. In this way, verification/validation methods can guarantee different requirements stated by the actual domain against the generated/modified/optimized software products. For example, a verified/validated model transformation can ensure the preservation of certain properties during the model-to-model transformation. This paper emphasizes the necessity of methods that make model transformation verified/validated, discusses the different scenarios of model transformation verification and validation, and introduces the principles of a novel test-driven method for verifying/validating model transformations. We provide a solution that makes it possible to automatically generate test input models for model transformations. Furthermore, we collect and discuss the actual open issues in the field of verification/validation of model transformations.

关键词: Graph rewriting based model transformations     Verification/validation     Test-driven verification    

Impact of crude distillation unit model accuracy on refinery production planning

Gang FU, Pedro A. Castillo CASTILLO, Vladimir MAHALEC

《工程管理前沿(英文)》 2018年 第5卷 第2期   页码 195-201 doi: 10.15302/J-FEM-2017052

摘要: In this work, we examine the impact of crude distillation unit (CDU) model errors on the results of refinery-wide optimization for production planning or feedstock selection. We compare the swing cut+ bias CDU model with a recently developed hybrid CDU model (Fu et al., 2016). The hybrid CDU model computes material and energy balances, as well as product true boiling point (TBP) curves and bulk properties (e.g., sulfur % and cetane index, and other properties). Product TBP curves are predicted with an average error of 0.5% against rigorous simulation curves. Case studies of optimal operation computed using a planning model that is based on the swing cut+ bias CDU model and using a planning model that incorporates the hybrid CDU model are presented. Our results show that significant economic benefits can be obtained using accurate CDU models in refinery production planning.

关键词: impact of model accuracy on production planning     swing cut+ bias CDU model     hybrid CDU model     refinery feedstock selection optimization     optimization of refinery operation    

Estimation of composite load model with aggregate induction motor dynamic load for an isolated hybrid

Nitin Kumar SAXENA,Ashwani Kumar SHARMA

《能源前沿(英文)》 2015年 第9卷 第4期   页码 472-485 doi: 10.1007/s11708-015-0373-7

摘要: It is well recognized that the voltage stability of a power system is affected by the load model and hence, to effectively analyze the reactive power compensation of an isolated hybrid wind-diesel based power system, the loads need to be considered along with the generators in a transient analysis. This paper gives a detailed mathematical modeling to compute the reactive power response with small voltage perturbation for composite load. The composite load is a combination of the static and dynamic load model. To develop this composite load model, the exponential load is used as a static load model and induction motors (IMs) are used as a dynamic load model. To analyze the dynamics of IM load, the fifth, third and first order model of IM are formulated and compared using differential equations solver in Matlab coding. Since the decentralized areas have many small consumers which may consist large numbers of IMs of small rating, it is not realistic to model either a single large rating unit or all small rating IMs together that are placed in the system. In place of using a single large rating IM, a group of motors are considered and then the aggregate model of IM is developed using the law of energy conservation. This aggregate model is used as a dynamic load model. For different simulation studies, especially in the area of voltage stability with reactive power compensation of an isolated hybrid power system, the transfer function of the composite load is required. The transfer function of the composite load is derived in this paper by successive derivation for the exponential model of static load and for the fifth and third order IM dynamic load model using state space model.

关键词: isolated hybrid power system (IHPS)     composite load model     static load     dynamic load     induction motor load model     aggregate load    

Digital twin-assisted gearbox dynamic model updating toward fault diagnosis

《机械工程前沿(英文)》 2023年 第18卷 第2期 doi: 10.1007/s11465-023-0748-0

摘要: One of the core challenges of intelligent fault diagnosis is that the diagnosis model requires numerous labeled training datasets to achieve satisfactory performance. Generating training data using a virtual model is a potential solution for addressing such a problem, and the construction of a high-fidelity virtual model is fundamental and critical for data generation. In this study, a digital twin-assisted dynamic model updating method for fault diagnosis is thus proposed to improve the fidelity and reliability of a virtual model, which can enhance the generated data quality. First, a virtual model is established to mirror the vibration response of a physical entity using a dynamic modeling method. Second, the modeling method is validated through a frequency analysis of the generated signal. Then, based on the signal similarity indicator, a physical–virtual signal interaction method is proposed to dynamically update the virtual model in which parameter sensitivity analysis, surrogate technique, and optimization algorithm are applied to increase the efficiency during the model updating. Finally, the proposed method is successfully applied to the dynamic model updating of a single-stage helical gearbox; the virtual data generated by this model can be used for gear fault diagnosis.

关键词: digital twin     gearbox     model construction     model updating     physical–virtual interaction    

Initiation of Setaria as a model plant

Xianmin DIAO,James SCHNABLE,Jeffrey L. BENNETZEN,Jiayang LI

《农业科学与工程前沿(英文)》 2014年 第1卷 第1期   页码 16-20 doi: 10.15302/J-FASE-2014011

摘要: Model organisms such as Arabidopsis ( ) and rice ( ) have proven essential for efficient scientific discovery and development of new methods. With the diversity of plant lineages, some important processes such as C photosynthesis are not found in either Arabidopsis or rice, so new model species are needed. Due to their small diploid genomes, short life cycles, self-pollination, small adult statures and prolific seed production, domesticated foxtail millet ( ) and its wild ancestor, green foxtail ( ), have recently been proposed as novel model species for functional genomics of the Panicoideae, especially for study of C photosynthesis. This review outlines the development of these species as model organisms, and discusses current challenges and future potential of a Setaria model.

关键词: Setaria     foxtail millet     C4 photosynthesis     model organism    

Methodologies for the establishment of an orthotopic transplantation model of ovarian cancer in mice

null

《医学前沿(英文)》 2014年 第8卷 第1期   页码 101-105 doi: 10.1007/s11684-014-0315-5

摘要:

This study used different methods to establish an animal model of orthotopic transplantation for ovarian cancer to provide an accurate simulation of the mechanism by which tumor occurs and develops in the human body. We implanted 4T1 breast cancer cells stably-transfected with luciferase into BALB/c mice by using three types of orthotopic transplantation methodologies: (1) cultured cells were directly injected into the mouse ovary; (2) cell suspension was initially implanted under the skin of the mouse neck; after tumor mass formed, the tumor was removed and ground into cell suspension, which was then injected into the mouse ovary; and (3) a subcutaneous tumor mass was first generated, removed, and cut into small pieces, which were directly implanted into the mouse ovary. After these models were established, in vivo luminescence imaging was performed. Results and data were compared among groups. Orthotopic transplantation model established with subcutaneous tumor piece implantation showed a better simulation of tumor development and invasion in mice. This model also displayed negligible response to artificial factors. This study successfully established an orthotopic transplantation model of ovarian cancer with high rates of tumor formation and metastasis by using subcutaneous tumor pieces. This study also provided a methodological basis for future establishment of an animal model of ovarian cancer in humans.

关键词: ovarian cancer     orthotopic transplantation     animal model    

Probabilistic model for vessel-bridge collisions in the Three Gorges Reservoir

Bo GENG , Hong WANG , Junjie WANG ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 279-285 doi: 10.1007/s11709-009-0044-z

摘要: Based on a field observation on vessel transit path of three bridges over the Yangtze River in the Three Gorges Reservoir, and an analysis of the geometric probabilistic model of transiting vessels in collision probability calculation, the aberrancy angle and vessel velocity probabilistic model related with impact force, a probabilistic model is established and also verified by goodness-of-fit test. The vessel transit path distribution can be expressed by the normal distribution model. For the Three Gorges Reservoir, the mean and standard deviation adopt 0.2 and 0.1, respectively ( is the channel width). The aberrancy angle distribution of vessels accepts maximum I distribution model, and its distribution parameters can be taken as 0.314 and 4.354. The velocity distribution of up-bound and down-bound vessels can also be expressed by the normal distribution model.

关键词: vessel-bridge collision     probabilistic model     parameter statistics    

The Construction of Tetrahedral Model of Engineering Ethical Evaluation

Jin Wang

《工程管理前沿(英文)》 2014年 第1卷 第1期   页码 62-70 doi: 10.15302/J-FEM-2014009

摘要: To achieve greatprojects, great attention should be attached to ethical issues of engineering. But endless immoralities in the field of engineering expose the lack of attention and the ineffectiveness of implementation of engineering ethical evaluation. The “Mirror” and the "Lamp" — these two metaphors used by M. H. Abrams vividly expose the differences in people's way of understanding which inspires author's study of the model of engineering ethical evaluation. With four elements of the project —artifact, engineer, user and environment, a tetrahedral model of integrity, strong restoring force and high stability is built. While their roles and responsibilities differ, each has to demonstrate a commitment to professional and ethical standards. In this model, four "Lamps" — i. e, four elements of engineering — in four corners provide light while four "Mirrors" — the result of reflection of four elements — reflect whether the tetrahedral model can truthfully evaluate the level of engineering ethics. The combination of the "Lamps" and "Mirrors" illuminates engineering ethical evaluation and leads to a plurality of evaluation standards, while simultaneously fostering both the avoidance of simple de-instrumentalization and the sustainability of ethical evaluation. Plurality of evaluation standards means the consideration of value differences in a multi-value state. The avoidance of de-instrumentalization means to prevent the engineer's expertise from fossilization. The sustainability of ethical evaluation accelerates the fulfillment of our dream, for the ultimate benefit of humankind. Ethical evaluation of the project not only helps more engineers to use expertise in pursuit of the public good, but also make more projects to meet people's short-term expectations and long-term cares.

关键词: tetrahedral model     ethical evaluation     engineering     Lamps and Mirrors    

河网水动力及综合水质模型的研究

张明亮,沈永明

《中国工程科学》 2008年 第10卷 第10期   页码 78-83

摘要:

采用Preissmann 4点隐式差分格式离散一维圣维南方程组,应用三级联解法求解河网水动力数学模型。基于河道-节点-河道算法的河网水质模型的求解特点,在WASP的水质模型理论基础上,建立了河网非稳态水动力综合生态水质数学模型,考虑了多个污染物变量的耦合计算、变量之间的相互转化和迁移。利用模型对4个河网算例进行验证。验证表明,水位和流量过程计算值与实测值吻合很好,各水质变量的计算值和实测值也符合较好,可见模型是合理可靠的,为河网的水质预测和管理提供了一个较为简便实用的工具。

关键词: Preissmann格式     河网     水动力模型     综合水质模型     WASP模型    

Extended model predictive control scheme for smooth path following of autonomous vehicles

《机械工程前沿(英文)》 2022年 第17卷 第1期   页码 4-4 doi: 10.1007/s11465-021-0660-4

摘要: This paper presents an extended model predictive control (MPC) scheme for implementing optimal path following of autonomous vehicles, which has multiple constraints and an integrated model of vehicle and road dynamics. Road curvature and inclination factors are used in the construction of the vehicle dynamic model to describe its lateral and roll dynamics accurately. Sideslip, rollover, and vehicle envelopes are used as multiple constraints in the MPC controller formulation. Then, an extended MPC method solved by differential evolution optimization algorithm is proposed to realize optimal smooth path following based on driving path features. Finally, simulation and real experiments are carried out to evaluate the feasibility and the effectiveness of the extended MPC scheme. Results indicate that the proposed method can obtain the smooth transition to follow the optimal drivable path and satisfy the lateral dynamic stability and environmental constraints, which can improve the path following quality for better ride comfort and road availability of autonomous vehicles.

关键词: autonomous vehicles     vehicle dynamic modeling     model predictive control     path following     optimization algorithm    

标题 作者 时间 类型 操作

The impacts of economic restructuring and technology upgrade on air quality and human health in Beijing-Tianjin-Hebei region in China

Chao Liu, Hancheng Dai, Lin Zhang, Changchun Feng

期刊论文

Standard model of knowledge representation

Wensheng YIN

期刊论文

张正彦:融合知识的预训练语言模型(2020年4月3日)

2022年04月18日

会议视频

受限空间火灾模型研究进展

郑昕,袁宏永

期刊论文

Elevated temperature creep model of parallel wire strands

期刊论文

Test-driven verification/validation of model transformations

László LENGYEL,Hassan CHARAF

期刊论文

Impact of crude distillation unit model accuracy on refinery production planning

Gang FU, Pedro A. Castillo CASTILLO, Vladimir MAHALEC

期刊论文

Estimation of composite load model with aggregate induction motor dynamic load for an isolated hybrid

Nitin Kumar SAXENA,Ashwani Kumar SHARMA

期刊论文

Digital twin-assisted gearbox dynamic model updating toward fault diagnosis

期刊论文

Initiation of Setaria as a model plant

Xianmin DIAO,James SCHNABLE,Jeffrey L. BENNETZEN,Jiayang LI

期刊论文

Methodologies for the establishment of an orthotopic transplantation model of ovarian cancer in mice

null

期刊论文

Probabilistic model for vessel-bridge collisions in the Three Gorges Reservoir

Bo GENG , Hong WANG , Junjie WANG ,

期刊论文

The Construction of Tetrahedral Model of Engineering Ethical Evaluation

Jin Wang

期刊论文

河网水动力及综合水质模型的研究

张明亮,沈永明

期刊论文

Extended model predictive control scheme for smooth path following of autonomous vehicles

期刊论文