检索结果-内蒙古大学图书馆

OPTIMIZATION OF URBAN MINI-BUS STOP SPACING: A CASE STUDY OF SHANGHAI (CHINA)

TEHNICKI VJESNIK-TECHNICAL GAZETTE 2017年第3期24卷 949-955页

作者： Zhu, Zhenjun Guo, Xiucheng Chen, Hongsheng Zeng, Jun Wu, Jiangling Southeast Univ Sch Transportat Jiangsu Prov Collaborat Innovat Ctr Modern Traff Jiangsu Key Lab Urban ITS Si Pai Lou 2 Nanjing 210096 Jiangsu Peoples R China Southeast Univ Sch Transportat Si Pai Lou 2 Nanjing 210096 Jiangsu Peoples R China Southeast Univ Sch Architecture Si Pai Lou 2 Nanjing 210096 Jiangsu Peoples R China Changan Univ Sch Highway Middle Sect South 2 Ring Rd Xian 710064 Peoples R China

In recent years, the mini-bus service has gained a rapid development, while the reasonable stop spacing is significant to improve residents' travel efficiency. In order to locate the mini-bus stops practically, this paper firstly proposes a mathematical model based on Voronoi Diagrams to minimize residents' total travel time. Improved Wilson-Han-Powell sequential quadratic programming (SQP) technique is employed to solve the model. Based on Geographic Information Systems (GIS), the Cartesian coordinate system is used to calculate the walking distance between mini-bus stops and origins or destinations, which cannot be directly measured. Secondly, based on the actual situation, this paper proposes modification methods for adjusting mini-bus stops. The validity and usefulness of the methodology is tested through applying it to a real case in Shanghai (China). The calculation results suggest that the model deals well with the mini-bus stop spacing problem.

关键词： mini-bus service modification methods optimization model sequential quadratic programming stop spacing Voronoi Diagrams

来源：评论

学校读者我要写书评

暂无评论

Application of SQP algorithm for fluorescence tomography with the time-domain equation of radiative transfer

引用

JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2017年 193卷 21-30页

作者： Qiao, Yao-Bin Qi, Hong Ren, Ya-Tao Sun, Jian-Ping Ruan, Li-Ming Harbin Inst Technol Sch Energy Sci & Engn 92West Dazhi St Harbin 150001 Peoples R China

A reconstruction scheme for the fluorescence tomography is investigated based on the time-domain radiative transfer equation (TD-RTE). Two coupled TD-RTES, which can provide considerable measurement data, are used as the forward model and solved by the discrete ordinate method. The sequential quadratic programming (SQP) is employed to build the reconstruction scheme for solving the inverse problem. The gradient of objective function is calculated efficiently by the adjoint equation technique. Considering the ill-posed nature of the inverse problem, the regularization term based on the generalized Gaussian Markov random field (GGMRF) model is adopted to enhance the reconstructed image. Influence of the initial guess, contrast, noisy data, and shape of the fluorescent target are analyzed. Simulated results show that the proposed algorithm performs efficiently and accurately on reconstructing the distribution of the fluorescence yield. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Time-domain equation of radiative transfer Fluorescence tomography Adjoint equation sequential quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Optimal rate control under geologic uncertainty: water flood and EOR processes

引用

OPTIMIZATION AND ENGINEERING 2017年第1期18卷 63-86页

作者： Taware, Satyajit Alhuthali, Ahmed H. Sharma, Mohan Datta-Gupta, Akhil Chevron Energy Technol Co Houston TX 77002 USA Saudi Aramco Dhahran Saudi Arabia Natl IOR Ctr Norway Stavanger Norway Texas A&M Univ College Stn TX USA

Much of the current world oil production comes from mature and partially depleted fields. Increasing the ultimate oil recovery from these fields is critical for meeting growing energy demands in the coming years. Many secondary oil recovery methods have been developed to improve oil recovery after primary depletion. The most widely used is water flooding because it is effective and relatively inexpensive to implement. However, the presence of reservoir heterogeneities, for example high permeability channels, can lead to premature breakthrough and poor sweep efficiency, resulting in reduced oil recovery. One way to improve the sweep efficiency is flood front management via the optimal allocation of production and injection rates. In this paper, we propose an optimal rate control strategy to maximize sweep efficiency and accelerate production during water flooding and EOR processes, in particular, polymer flooding and CO2 injection. We describe our approach and the underlying mathematical formulation, and then we illustrate its power using field-scale examples. We demonstrate the practical feasibility of our method in realistic production scenarios using a 3D synthetic benchmark field example, the Brugge field. We also use stochastic optimization to take geological uncertainty into consideration. The value of using multiple realizations in improving the robustness of the optimization in terms of oil recovery and enhancing NPV is clearly illustrated by the 3D example.

关键词： Reservoir managament Rate optimization Production optimization sequential quadratic programming Enhanced oil recovery Waterflood

来源：评论

学校读者我要写书评

暂无评论

Predictive planning of optimal velocity and state of charge trajectories for hybrid electric vehicles

引用

CONTROL ENGINEERING PRACTICE 2017年 61卷 229-243页

作者： Heppeler, Gunter Sonntag, Marcus Wohlhaupter, Uli Sawodny, Oliver Univ Stuttgart Inst Syst Dynam Waldburstr 17-19 D-70569 Stuttgart Germany Daimler AG Stuttgart Germany

The combination of electric motors and internal combustion engines in hybrid electric vehicles (HEV) can considerably improve the fuel efficiency compared to conventional vehicles. In order to use its full potential, a predictive intelligent control system using information about impending driving situations has to be developed, to determine the optimal gear shifting strategy and the torque split between the combustion engine and the electric motor. To further increase fuel efficiency, the vehicle velocity can be used as an additional degree of freedom and the development of a predictive algorithm calculating good choices for all degrees of freedom over time is necessary. In this paper, an optimization-based algorithm for combined energy management and economic driving over a limited horizon is proposed. The results are compared with results from an offline calculation, which determine the overall fuel savings potential through the use of a discrete dynamic programming algorithm. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Hybrid vehicles Dynamic programming sequential quadratic programming Energy management Potential analysis Velocity optimization Predictive control Economic driving

来源：评论

学校读者我要写书评

暂无评论

Reinforcement Learning-Based Optimal Flat Spin Recovery for Unmanned Aerial Vehicle

引用

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2017年第4期40卷 1074-1081页

作者： Kim, Donghae Oh, Gyeongtaek Seo, Yongjun Kim, Youdan Seoul Natl Univ Dept Mech & Aerosp Engn Seoul 08826 South Korea Seoul Natl Univ Dept Mech & Aerosp Engn Inst Adv Aerosp Technol Seoul 08826 South Korea

A study proposed an reinforcement learning (RL)-based optimal controller to recover the aircraft from flat spin mode to steady level flight in minimum time. Stable upset modes including flat spin were investigated via a bifurcation diagram (BD). A two-phase controller including an RL block was designed, angular velocity was attenuated to a safe margin, and in the second phase, the attitude controller restored the aircraft to level flight. The performance of the proposed controller was demonstrated by comparing the numerical simulation result to that of the optimal trajectory obtained by a sequential quadratic programming (SQP) and a genetic algorithm (GA).

关键词： UAV Reinforcement Learning Elevator Deflection Ailerons Sideslip Angle Trajectory Optimization Level Flight sequential quadratic programming Nonlinear programming Linear quadratic Regulator

来源：评论

学校读者我要写书评

暂无评论

Signal censoring and fusing with system-level communication constraints in multistatic radar: a J-divergence and Bhattacharyya distance-based approach

引用

IET RADAR SONAR AND NAVIGATION 2017年第12期11卷 1802-1814页

作者： Cao, Ding Zhou, Shenghua Liu, Hongwei Liu, Jun Zang, Huikai Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Shaanxi Peoples R China Xidian Univ Collaborat Innovat Ctr Informat Sensing & Underst Xian 710071 Shaanxi Peoples R China

Decentralised detection using censored observations is an effective way to mitigate communication constraints where each sensor only transmits the informative' observations to a fusion centre (FC), and censors those deemed uninformative'. In this study, a censoring rule is used at each spatial diversity channel such that only the observation exceeding a local threshold is transmitted, where the local threshold controls the communication rate. In particular, the authors consider a scenario where there exists a communication constraint at the FC. To design a proper communication bandwidth allocation (CBA) algorithm, two Ali-Silvey distance measures, i.e. the J-divergence (JD) and Bhattacharyya distance (BD), are utilised as objective functions to achieve a manageable optimisation procedure for designing local thresholds. The CBA algorithm is proposed by solving a constrained non-linear programming problem through the sequential quadratic programming method. Besides, the detection performance is analysed under the censoring scheme, given the optimised local thresholds. Numerical results indicate that the two Ali-Silvey distance-based algorithms can outperform the uniform bandwidth allocation strategy;meanwhile, the BD-based method performs better at high signal-to-noise scenarios but slightly worse at low, compared with the JD-based method.

关键词： radar signal processing sensor fusion telecommunication control bandwidth allocation diversity reception optimisation signal censoring signal fusing system-level communication constraints multistatic radar J-divergence Bhattacharyya distance decentralised detection communication constraint mitigation informative observations fusion centre spatial diversity channel local threshold communication rate control communication bandwidth allocation Ali-Silvey distance measures optimisation procedure constrained nonlinear programming problem sequential quadratic programming

来源：评论

学校读者我要写书评

暂无评论

Optimal design of extractive distillation for acetic acid dehydration with N-methyl acetamide

引用

CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION 2017年 120卷 301-316页

作者： You, Xinqiang Gu, Jinglian Peng, Changjun Rodriguez-Donis, Ivonne Liu, Honglai East China Univ Sci & Technol State Key Lab Chem Engn Shanghai 200237 Peoples R China East China Univ Sci & Technol Dept Chem Shanghai 200237 Peoples R China Chongqing Univ Sch Chem & Chem Engn Chongqing 400044 Peoples R China Univ Toulouse INRA ENSIACET INPT Lab Chim Agroind Toulouse France

A distinctive strategy for entrainer recycling is proposed in this work for acetic acid (AA) dehydration by extractive distillation by using N methyl acetamide (NMA). The use of standard entrainers such as DMF or DMSO has the main drawback of forming an azeotrope with acetic acid. However, the vapour liquid equilibrium AA NMA exhibits a tangential pinch point at NMA end composition. The new strategy rises from the thermodynamic analysis of the ternary diagram that which involves no azeotrope. As a result, acetic acid with high purity can be obtained by the recycling of the entrainer with a relaxed constraint in its purity. Optimization studies are discussed by using two approaches: two-step optimization method with sequential quadratic programming (TSOM case) and the multi-objective genetic algorithm. The multi-objective genetic algorithm allowed the computation of the optimal acetic acid dehydration with an impurity of 3% in the recycled entrainer. Significant cost savings are achieved thanks to the optimization of both columns together. Energy consumption is reduced by 12.8% and 56.9% whereas TAC is saved by 28.4% and 56.3% compared with optimal case TSOM (impurity content 1%) and a published "Case Ref" (impurity content 0.01%), respectively.

关键词： Acetic acid dehydration Extractive distillation sequential quadratic programming Multi-objective optimization Genetic algorithm

来源：评论

学校读者我要写书评

暂无评论

Optimal Variable Amplitudes Input Shaping Control for Slew Maneuver of Flexible Spacecraft

引用

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2017年第12期40卷 3255-3263页

作者： Wang, Jie Li, Dongxu Jiang, Jianping Natl Univ Def Technol Coll Aerosp Sci & Engn 47 Yanwachi St Changsha 410073 Hunan Peoples R China

来源：评论

学校读者我要写书评

暂无评论

Improved sequential quadratic programming Algorithm of Reactive Voltage Optimization

Improved Sequential Quadratic Programming Algorithm of React...

引用

Asia-Pacific Power and Energy Engineering Conference (APPEEC)

作者： Wang Ke Wang Le Guangxi Power Grid Corp Nanning Power Supply Bur Nanning Peoples R China Guangxi Univ Sch Elect Engn Nanning Peoples R China

ISBN: (纸本)9781424462551

Apply sequential quadratic programming algorithm into large power system's reactive voltage optimization and introduce exact penalty function as algorithm improvement. Use improved global sequential quadratic programming algorithm to do the reactive power optimization algorithm to IEEE 30-bus system and IEEE 118-bus system. The result shows that the global sequential quadratic programming algorithm, with good global convergence, is effective on reactive power optimization algorithm.

关键词： sequential quadratic programming Reactive voltage optimization MATLAB

来源：评论

学校读者我要写书评

暂无评论

Assessing Accessibility of Main-Belt Asteroids Based on Gaussian Process Regression

引用

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2017年第5期40卷 1144-1154页

作者： Shang, Haibin Liu, Yuxin Beijing Inst Technol Sch Aerosp Engn Key Lab Dynam & Control Flight Vehicle Beijing 100081 Peoples R China Delft Univ Technol Fac Aerosp Engn NL-2629 HS Delft Netherlands

The main-belt asteroids are of great scientific interest and have become one of the primary targets of planetary exploration. In this paper, the accessibility of more than 600,000 main-belt asteroids is investigated. A computationally efficient approach based on Gaussian process regression is proposed to assess the accessibility. Two transfer models consisting of globally optimal two-impulse and Mars gravity-assist transfers are established, which would serve as a source of training samples for Gaussian process regression. The multistart and deflection technologies are incorporated into the numerical optimization solver to avoid local minima, thereby guaranteeing the quality of the training samples. The covariance function, as well as hyperparameters, which dominate the regression process, are chosen elaborately in terms of the correlation between samples. Numerical simulations demonstrate that the proposed method can achieve the accessibility assessment within tens of seconds, and the average relative error is only 1.33%. Mars gravity assist exhibits significant advantage in the accessibility of main-belt asteroids because it reduces the total velocity increment by an average of 1.23 km/s compared with the two-impulse transfer. Furthermore, it is observed that 3976 candidate targets have potential mission opportunities with a total velocity increment of less than 6 km/s.

关键词： Gaussian Process Asteroids Formation and Evolution of the Solar System Numerical Optimization Numerical Simulation sequential quadratic programming Earth Orbital Elements Interplanetary Mission Orbital Inclination

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：