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FL-FN-MOGA Based Traffic Signal Control

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Journal of Systems Engineering and Electronics 2003年第3期14卷 14-23页

作者： Wei Wu & zhang Yi department of Automation, tsinghua university, beij.ng 100084, P. R. china department of Automation Tsinghua University Beijing 100084 P. R. China

In this paper, a traffic signal control method based on fuzzy logic (FL), fuzzy-neuro (FN) and multi-objective genetic algorithms (MOGA) for an isolated four-approach intersection with through and left-turning movements is presented. This method has an adaptive signal timing ability, and can make adjustments to signal timing in response to observed *** 'urgency degree' term, which can describe the different user's demand for green time is used in decision-making by which strategy of signal timing can be determined. Using a fuzzy logic controller, we can determine whether to extend or terminate the current signal phase and select the sequences of phases. In this paper, a method based on fuzzy-neuro can be used to predict traffic parameters used in fuzzy logic controller. The feasibility of using a multi-objective genetic algorithm ( MOGA) to find a group of optimizing sets of parameters for fuzzy logic controller depending on different objects is also demonstrated. Simulation results show that the proposed methed is effecfive to adjust the signal timing in response to changing traffic conditions on a real-time basis, and the controller can produce lower vehicle delays and percentage of stopped vehicles than a traffic-actuated controller.

关键词： Traffic signal control Fuzzy logic Fuzzy-neuro Multi-objective genetic algorithms.

Strategies for development of clean energy in china

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Petroleum Science 2008年第2期5卷 183-188页

作者： Yang Zhen zhang Hongliang department of Environmental sciences and Engineering Tsinghua University Beijing 100084 China

A development framework of clean energy in china is put forward based on core development strategy, technology support, and policy and laws support. In this framework, the priority development and strategic backup of ... 详细信息

关键词： china clean energy strategy framework

Research Development of Endocrine Disrupting Chemicals(EDCs) in Water in china

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Biomedical and Environmental sciences 2003年第1期16卷 62-67页

作者： HOng ZHOU, XIAO-JIAN zhang, AND ZHAN-SHEng WAngdepartment of Environmental sciences and Engineer, tsinghua university, beij.ng 100084, china department of Environmental sciences and Engineer Tsinghua University Beijing 100084 Chin

More and more importance has been attached to the problem of endocrine disrupting chemicals (EDCs) since 1960s. This article elaborates the recent research progress of EDCs in water and the trends in the near future i... 详细信息

关键词： Endocrine disrupting chemicals Source water Alkylphenols Phthalates Atrazine

Effect of Coarse Aggregate Size on Relationship between Stress and Crack Opening in Normal and High Strength Concretes

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Journal of Materials Science & Technology 2005年第5期21卷 85-94页

作者： Jun zhang Qian LIU and Lin WAngDepaxtment of Civil Engineering, tsinghua university, beij.ng 100084, china department of Civil Engineering Tsinghua University Beijing 100084 China

Fine and coarse aggregates play an important role in the fracture of concrete. However, quantitative informationavailable on the effect of the coarse aggregate size on the fracture properties of concrete is still limited. In the presentpaper, the effect of coarse aggregate size (single grade of 5~10, 10~16, 16~20 and 20~25 mm) on stress-crackopening (σ-ω) relation in normal and high strength concretes (compressive strength of 40 and 80 MPa, respectively)was studied. The investigation was based on three-point bending tests implemented by fictitious crack analysis. Theresult shows that coarse aggregate size and cement matrix strength significantly influence the shape of σ-ω *** a given total aggregate content, in normal strength concrete, smaller size of aggregate leads to a high tensilestrength and a sharp stress drop after the peak stress. The smaller the coarse aggregate, the steeper the σ-ω *** contrast, in high strength concrete, the effect of aggregate size on σ-ω relation almost vanishes. A similar σ-ωrelation is obtained for the concrete except for the case of 20~25 mm coarse aggregate size. The stress drop afterthe peak stress is more significant for high strength concrete than that for normal strength concrete. Meanwhile, thesmaller the coarse aggregate size, the higher the flexural strength. Fracture energy and characteristic length increasewith increasing coarse aggregate size in both normal and high strength concretes.

关键词： Aggregate size Stress-crack opening relation Fracture energy Bending test

CO_2 Mitigation in Coal Gasification Cogeneration Systems with Integration of the Shift Reaction, CO_2 Absorption and Methanol Production

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Journal of Thermal Science 2004年第3期13卷 193-198页

作者： Yuanyuan DUAN Jin zhang Key Laboratory of Thermal Science and Power Engineering, department of Thermal Engineering, tsinghua university, beij.ng 100084, china Key Laboratory of Thermal Science and Power Engineering Department of Thermal Engineering Tsinghua University Beijing China

Cogeneration of electricity and liquid fuel can achieve higher efficiencies than electricity generation alone in Integrated Gasification Combined Cycle (IGCC), and cogeneration systems are also expected to mitigate CO2 emissions. A proposed methanol-electricity cogeneration system was analyzed in this paper using exergy method to evaluate the specified system. A simple cogeneration scheme and a complicated scheme including the shift reaction and CO2 removal were compared. The results show that the complicated scheme consumes more energy, but has a higher methanol synthesis ratio with partial capture of *** those methanol and electricity cogeneration systems, the CO2 mitigation is not merely an additional process that consumes energy and reduces the overall efficiency, but is integrated into the methanol production.

关键词： cogeneration system methanol synthesis CO2 mitigation exergy analysis

Measurement of Mean Burst Period in WallTurbulence by Wavelet Analysis

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Communications in Nonlinear Science and Numerical Simulation 1999年第3期4卷 3-5页

作者： Li LI Chunxiao XU Zhaoshun zhang and Guialang CUI(department of Engineering Mechanics, tsinghua university, beij.ng 100084, china) department of Engineering Mechanics Tsinghua University Beijing 100084 China

IntroductionInwallturbulence,theejectionoflow-speedfluidfromthewallandthesweepofth***urst,andwhentheflowisbursting,therealwaysea... 详细信息

IntroductionInwallturbulence,theejectionoflow-speedfluidfromthewallandthesweepofth***urst,andwhentheflowisbursting,therealwaysea...

关键词： turbulence burst phenomena wavelet analysis

Non-linear Identification Based on the Method of Gauss Functions

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Communications in Nonlinear Science and Numerical Simulation 1997年第3期2卷 39-44页

作者： Qing zhang & Chongde LU (department of Thermal Engineering, tsinghua university ,beij.ng, 100084) department of Thermal Engineering Tsinghua University Beijing 100084 China

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关键词： identification the method of gauss functions whole optimization

The application of event-tree based approach in long-term crude oil scheduling

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Science china Chemistry 2010年第6期53卷 1445-1452页

作者： ZOU LaiXi,LI ChuFu,zhang Ming & HE XiaoRong department of Chemical Engineering,tsinghua university,beij.ng 100084,china 1. department of Chemical Engineering Tsinghua University Beijing 100084 China

This paper addresses the problem of optimal operation in long-term crude oil scheduling,which involves unloading crude oil from vessels,transferring it to charging tanks and feeding it to the distillation *** application of a new approach for modeling and optimization of long-term crude oil scheduling is presented and the event-tree based modeling method that is very different from mathematical programming is *** approach is developed on the basis of natural language modeling and continuous time *** triggered rules,decomposition strategy,depth-first search algorithm and pruning strategy are adopted to improve the efficiency of searching the optimum *** approach is successfully applied to an industrial-size problem over a horizon of 4 weeks,involving 7 vessels,6 storage tanks,6 charging tanks,2 crude oil distillation units,and 6 crude oil *** CPU (AMD 3000+,2.0GHz) solving time is less than 70 seconds.

关键词： crude oil scheduling modeling and optimization event-tree based depth-first search algorithm

Study on Bonding of Steel-mushy Al-7graphite

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Journal of university of Science and Technology beij.ng 2001年第4期8卷 283-285页

作者： Peng zhang, Yunhui Du, Daben Zeng department of Mechanical Engineering tsinghua university. beij.ng 100084, china Tsing Hua Univ Dept Mech Engn Beijing 100084 Peoples R China

The bonding of steel-mushy Al-7graphite was studied. The relationship between interfacial shear strength of bonding plate and solid fraction of Al-7graphite mushy was obtained, and the interfacial structure of bonding plate was determined. The results showed that: under the condition of 500 degreesC for preheat temperature of steel plate and 10 mm/s for rolling speed, the largest interfacial shear strength of bonding plate was 70.1 MPa when solid fraction of Al-7graphite mushy was 34.6%.

关键词： interfacial shear strength solid fraction interfacial structure