In this paper, a novel finite-time fault-tolerant trajectory tracking controller is created to render a marine vehicle to enhance tracking performance in the presence of complex unknown variables, including model uncertainties, environmental disturbances, and actuator faults. An adaptive fault-tolerant finite-time sliding mode controller is designed by introducing adaptive control techniques, the non-singular fast terminal sliding mode (NSFTSM) function, and a radial base function (RBF) neural network. The radial base function neural network (RBFNN) is developed to eliminate the influences of model uncertainties and environmental disturbances. A fault compensation by integrating the adaption technique is designed to reduce the effects of actuator faults and approximation errors. Suffering from uncertainties and actuator faults, the proposed finite-time tracking controller can track the desired trajectory with high precision. Simulation results and compared simulations indicate the efficiency and superiority of the proposed controller.

为优化养老机构配置,构建了兼顾公平和效率的养老机构空间配置优化模型.以上海市闵行区为例,采用改进遗传算法与GIS技术,分析现有养老机构在空间分布和规模上的合理性.在对老年人口数量预测的基础上优化养老机构配置,提出优化方案,并探讨方案的合理性和模型求解算法的优越性.结果表明:研究区现有养老机构缺口大,部分机构偏离最佳区位.有3所养老机构在现有区位运行欠合理,部分养老机构需适当调整规模,需增设13所养老机构.优化后的养老机构配置方案公平性提高59.71％,居民出行效率提高47.30％,投资者经济效率提高7.25％.在优化过程中,改进遗传算法的求解精度和求解效率优于传统的粒子群算法、模拟退火算法和一般遗传算法.

This paper studies the fuzzy finite-time nonsingular terminal sliding mode (FTNTSM) control problem for state/error-constrained and uncertain Euler-Lagrange systems with several contributions: (1) a modified FTNTSM manifold is designed to ensure finite-time stabilization of error dynamics and prescribed tracking accuracy; (2) a new barrier Lyapunov function (BLF) candidate, not only intended for sliding mode control design, but also devoted to constraint satisfaction, is constructed. The BLF candidate is a universal one, as it works uniformly for both constrained and unconstrained systems without changing the control structure; and (3) a fuzzy logic system is employed to dynamically compensate modeling inaccuracies and external disturbances. Meanwhile, a terminal dynamics-based gradient descent algorithm with an accelerated learning process is established to train the weight online. Numerical simulations on a robot manipulator demonstrate the theoretical findings.

ABSTRACT In this paper, a finite-time control method has been proposed for underactuated unmanned surface vehicles (USVs) with external disturbances in order to implement trajectory tracking control. Considering the complexity of the marine environment and the high-accuracy and rapidity required by USVs to complete complex marine missions, such as water quality detection, underwater pipe-laying, rescue operations and so on, a novel hierarchical sliding mode base on non-singular terminal sliding mode control (NTSMC) method is designed for underactuated USVs to ensure that all tracking error can faster converge to a neighbourhood around zero within finite time and address effectively the singularity problem which always exist in terminal sliding mode control (TSMC). The underactuated problem is addressed by hierarchical sliding mode technique. Meanwhile, the dynamic surface control (DSC) is employed to address the explosion problem of computational complexity in traditional method. Further, a novel finite-time disturbance observer (FDO) is devised to estimate accurately the unknown environmental disturbances and for practicality, a saturation constraint function is used to limit the input of the controller. Finally, the effectiveness and stability of the proposed method are validated by simulations and comparisons.

首先,基于实物期权构建PPP项目价值评估模型,用以确定项目未来价值,明确项目特许期调整区间;接着,考虑再谈判双方压力因子的不同以及谈判破裂的可能性,建立非对称压力讨价还价博弈模型;最后,以某污水处理项目为例进行模型应用分析.结果表明,非对称信息下,参与再谈判的双方收益不确定,社会资本在谈判中存在"先发制人"优势,政府可通过释放谈判信号获得优势,双方的心理状态也会影响再谈判的博弈结果,政府谈判采取"对半砍价"策略较为有利.

Formation control of unmanned surface vehicles (USVs) can perform numerous complex tasks effectively which are difficult or impossible for a single USV in highly dynamic waters. In this paper, a novel formation control method based on the leader-follower method considering the heading angle of leader has been proposed. When turning, the formation is divided into inner side and outer side, naturally. Specifically, due to the characteristics of large inertia and underactuated, USVs on the inside with a shorter desired trajectory so that untimely braking can lead to the collision of members. On the contrary, USVs located on the outside need to travel longer. Inappropriate control strategy is easy to cause the failure even damage of the whole formation control system. First, the virtual structure of the formation was determined based on the number and shape of formation. Then, the track points of followers have been generated by linear translation combining formation structure and heading angle of leader. Further, the smooth and continuous of trajectory generated have been guaranteed by constructing an optimization function of minimum snap between adjacent trajectory points. When the formation travels in a straight line, the algorithm does not work, but works when turning. Finally, the proposed method has been verified by simulation experiments.

This paper is focused on the stabilization of Takagi–Sugeno fuzzy model-based Markovian jump systems with the aid of a delayed state observer. Due to network-induced constraints in the communication channel, a delay partition method combined with an event-triggered mechanism is proposed to design the observer. Then, a novel integral sliding surface is designed, based on which sliding mode dynamics is obtained. Further, according to stochastic stability theory, feasible conditions are provided to ensure the sliding mode dynamics and the error dynamics have an H∞ attenuate level γ. The challenge is to deal with the issue that transition rates may be totally unknown. Moreover, an observer-based sliding mode controller is constructed to ensure the finite-time reachability of the predefined sliding surface. Finally, a numerical example based on a robotic manipulator is given to verify the effectiveness of the proposed method.

In this paper, a leader–follower formation control strategy is presented based on adaptive neural network and disturbance observer, which is aimed at resolving model uncertainties as well as the time-varying disturbances for autonomous underactuated surface vessels. The model uncertainties which can be expressed by unknown nonlinear functions are approximated and compensated by the adaptive neural network. The disturbance observer introduced can estimate time-varying disturbances and compensate them to the feedforward control loop, so as to make the external time-varying disturbances suppressed and the robustness of controller against the disturbances improved. The dynamic surface control technology is applied in the procedure of designing the controller through utilizing the backstepping method, which solves the computational explosion of the derivative of virtual control signals. Finally, through Lyapunov analysis, the stability of adaptive neural formation control system is proved and all the error signals uniformly converge to a very small range ultimately. The excellent performance of the presented formation control strategy is demonstrated through numerical simulations.

ABSTRACT The trajectory tracking method for an unmanned surface vehicle (USV) using integral terminal sliding mode integral backstepping adaptive control (ITSMIBAC) scheme is presented in this paper, which takes into account external disturbances and uncertain model parameters. Furthermore, finite-time convergence and excellent track tracking effect are guaranteed by the differential equations that is made up of the integral terminal sliding mode function. In particular, a backstepping method adding integral term is used to ensure the globally asymptotic stability of system and make the differential equations to converge to zero. The upper bound of the disturbances including external disturbances and uncertain model parameters is estimated by an adaptive control law. Finally, the effectiveness and the feasibility of the proposed controller are demonstrated by numerical example and comparison result through tracking circular orbit.

科学评价养老设施空间可达性是其合理配置的基础.基于地理信息系统(GIS)技术,纳入养老设施规模等级因素,采用高斯两步移动搜索(2SFCA)法对上海市中心城区养老设施的空间可达性进行了测算,并采用空间自相关分析探讨了养老设施空间可达性和老年人口密度的关系.结果表明:上海市中心城区各街道养老设施的可达性分布不均,整体上呈现南高北低的分布格局;各区中型养老设施空间可达性稍优于大型养老设施,且均明显优于小型养老设施.未来应充分考虑上海市中心城区地理特征、交通网络和人口分布特点进一步合理配置养老设施.研究结果为上海市养老设施的配置和优化提供了决策依据.

以我国19个邻避设施PPP项目为研究样本,采用扎根理论方法分析邻避设施PPP项目风险.通过数据收集和编码,构建关键风险体系,并对风险间的关联性进行阐释,基于研究结果提出风险防范启示:强化政府契约意识、完善论证评估机制;考虑多元利益诉求,构建动态调整机制;重视公众参与,引入绩效评价机制.

为了解邻避设施PPP项目中公共部门、私人部门和公众的行为选择及其影响因素,将演化博弈方法与系统动力学方法相结合开展研究.首先,在三方具有有限理性的前提下,构建三方演化博弈模型,对三方主体的互动行为及稳定状态进行分析;然后,在此基础上采用系统动力学方法对三方演化博弈过程进行动态模拟仿真,研究各种不确定性因素对博弈演化过程的影响,为制定相关政策提供依据;最后,根据仿真结果提出对策建议.仿真结果表明,三方主体的策略选择由多个外部变量因素共同作用,通过改变仿真系统中的外部变量取值,系统最终能达到(政府积极监管、企业积极努力、公众参与监督)的均衡状态;在三方博弈过程中,政府起引导作用,公众的监督作用不容忽视,合理的惩罚方案有助于减少企业机会主义行为.因此,可从构建多主体协调机制、重视公众参与监督、构建社会监督保障体系、设计合理的激励方案等方面促进邻避设施PPP项目顺利开展.

There exist great risks in the construction of deep foundation pit. In order to know the key risks affecting the construction of deep foundation pit, we put forward an improved failure mode and effect analysis (FMEA) method which combined 2-tuple linguistic and grey relational analysis (GRA). Based on the traditional FMEA method, the linguistic assessment information by decision makers is represented by means of 2-tuple linguistic variables and the multi-granularity issue is taken into account. Furthermore, the risks are ranked by using GRA. A deep foundation pit construction project is taken as an example to demonstrate and validate the proposed method. By using the improved FMEA approach,the most critical risks in deep foundation pit construction process can be identified. The proposed method overcomes the inherent weaknesses of the traditional FMEA method and provides a reliable and distinguishable risk ranking system by considering the weight of risk factors and decision behavior of decision makers. Compared with the traditional FMEA method, the proposed method can deal with the language information more precisely,reduce the information distortion and loss,and improve the precision and reliability of the risk ranking.The study provides a comprehensive risk identification and evaluation tool for the risk analysis of deep foundation pit construction.

综合考虑政府、居民、投资者3方需求,构建带约束多目标的养老机构配置优化模型,基于改进免疫算法和GIS技术,对上海市虹口区养老机构的配置优化问题进行研究,分析研究区现有养老机构在空间分布和规模配置上的合理性,提出优化配置方案.研究表明:研究区现有养老机构数量缺口较大、部分养老机构偏离最佳区位、规模与需求存在较大差距;3所位于江湾镇街道的养老机构在现有区位运行欠合理;为充分满足居民养老需求,需在虹口区南部地区增设15所养老机构;通过与一般免疫算法、遗传算法、粒子群算法、模拟退火算法得到的优化结果对比可知,改进免疫算法在此优化问题中的求解效率分别提高45％,38.89％,21.43％,46.34％,求解精度分别提高1.61％,2.73％,5.80％,6.91％.

Medical services are the basic requirement of the public and are closely related to public health.The rationality of the layout and spatial accessibility of medical facilities are closely related to the right of the public to healthcare.Spatial accessibility of medical facilities represents the convenience for residents to obtain medical services.Using GIS and an improved potential model that introduces population scale factor and medical facility grade influence coefficient to traditional potential model,the spatial accessibility of urban medical facilities in Yangpu District of Shanghai was studied.By applying a spatial interpolation method,accessibility of medical facilities of Yangpu District in 2016 was obtained.Moreover,hotspot analysis was used for the cluster analysis of spatial accessibility.The results indicate that the spatial accessibility of urban medical facilities in different community of Yangpu District varies.The spatial accessibility in the central area of Yangpu District is higher than that of other areas.Spatial accessibility is relatively high in Daqiao subdistrict,Dinghai Road subdistrict,and some areas of Yinxing subdistrict.Hospitals of the same grade in the subdistricts of the central area are so closely located that medical resources are of high concentration in these areas.Overall,spatial accessibility of tertiary hospitals is better than secondary and primary hospitals in Yangpu.The improved potential model can evaluate the spatial accessibility of urban medical facilities reasonably by integrating population in demands,travel impedance between residential areas and medical facilities,and the influence of medical facility grade on residents' choice of medical services.By using GIS,the difference of spatial accessibility of urban medical facilities can be visualized.Furthermore,areas with insufficient medical resources can be defined.The results can not only enrich public facility spatial planning theory,but also provide references for the decision making of relevant government departments.

为进一步激发民间有效投资活力、促进经济持续健康发展,政府大力推广PPP模式,尤其鼓励社会资本进入基础设施及服务领域.截至2016年年底,全国入库PPP(Public-private partnership)项目共计11260个,投资额达到13.5万亿元.其中,生态建设与环境保护行业的PPP项目签约率位于各行业PPP项目前列,其中城市污水处理项目备受重视.关于城市污水PPP项目的处理价格存在多种不确定因素,会影响政府最初对污水处理价格补贴的合理性.本文用敏感性分析方法对影响PPP合同价格的各不确定性因素进行分析,提出了动态调价模型,并以上海市某污水处理厂为例进行案例分析,以期对建立有效的PPP项目动态调价机制提供思路和对策.

基于非期望产出的SBM方向性距离函数,对中国30个省份2004—2014年间碳排放约束下的建筑业环境效率及其分解进行测算.研究表明:碳排放和机械设备无效率是建筑业环境无效率的主要来源;建筑业环境效率水平呈"东高西低"的分布格局.

In order to study the influence factors and the behavioral options of government and people whose house will be dismantled during the demolition process, an evolutionary game model is established based on the assumption that both the government and the households have bounded rationality.The interaction mechanism between the government and households and the stable state are discussed according to the established model.Furthermore, a system dynamics model is established and the dynamic influence on behavioral options of different factors is analyzed by data simulation.The simulation results show that the administrative cost and the deficiency of public credibility have significant impact on government decision-making.The results also indicate that the compensation cost and the fighting cost affect the behavioral options of the households.Therefore, the government should design reasonable compensation mechanisms, enhance communication with households and improve the public credibility in demolition projects.

Based on data envelopment analysis (DEA) and Malmquist index,the spatial differences and temporal changes of infrastructure investment efficiency for 287 cities at prefecture level and above are evaluated.The reasons for the change of investment efficiency are analyzed according to the decomposed indices of efficiency.The results indicate that the total investment efficiency of urban infrastructure in China is at medium level now.Infrastructure investment efficiency is closely related to the regional economic development level,city administrative grade and urban scale.The cities in different region have different situation of return to scale and the impact of scale efficiency on overall efficiency are larger than that of pure technical efficiency.From 2003 to 2012,the urban infrastructure investment efficiency decreased first and then increased steadily.Technical improvement makes a great contribution to the increase of Malmquist productivity index.

In order to properly evaluate the port logistics services capacity,a combination evaluation model is proposed.Firstly,five evaluation methods are used to evaluate the logistics capability and Kendall-W coefficient is used to test the coherence of results obtained by different methods.Then,four combined methods are applied to combine the results and Spearman rank coefficient is used for getting the final result.Finally,15 ports are discussed as a case study to demonstrate the merit of the integrated framework.This study provides a new approach to assess the port logistics capacity.