Data dependent input control for origin–destination demand estimation using observability analysis

In this paper, we address the observability issue of static O–D estimation based on link counts. Unlike most classic observability analyses that relied only on network topological relationships, our analysis incorporates the actual values of input parameters, thus including network operational relations as well. We first analyze possible mathematical properties of an O–D estimation problem with different data input. We then propose a modeling approach based on mixed-integer program for selecting model input that ensures observability and estimation quality. Through establishing a stronger connection between observability analysis and the corresponding estimation problem, the proposed method aims to improve estimation quality while reducing reliance on erroneous data.     

海洋平台海洋平台常用流量计的选型分析

文章主要介绍了海洋平台常用流量计的原理和特点,结合海洋平台的特点叙述了流量计选型时的注意事项,并给出了海洋平台常用流量计的选型原则和计算方法,为海洋平台选出最合适的流量计提供了一种方案。     

A carbon footprint-based closed-loop supply chain model under uncertainty with risk analysis: A case study

The management of products’ end-of-life and the recovery of used products has gained significant importance in recent years. In this paper, we address the carbon footprint-based problem that arises in a closed-loop supply chain where returned products are collected from customers. These returned products can either be disposed of or be remanufactured to be resold as new ones. Given this environment, an optimization model for a closed-loop supply chain (CLSC) in which carbon emission is expressed in terms of environmental constraints, i.e., carbon emission constraints, is developed. These constraints aim to limit the carbon emission per unit of product supplied with different transportation modes. Here, we design a closed-loop network where capacity limits, single-item management and uncertainty on product demands and returns are considered. First, fuzzy mathematical programming is introduced for uncertain modeling. Then, the statistical approach to the possibility to synthesize fuzzy information is utilized. Therefore, using a defined possibilistic mean and variance, we transform the proposed fuzzy mathematical model into a crisp form to facilitate efficient computation and analysis. Finally, the risk caused by violating the estimated resource constraints is analyzed so that decision makers (DMs) can trade off between the expected cost savings and the expected risk. We utilize data from a company located in Iran.     

大城市中小学周边地区交通拥堵问题分析与解决策略

交通拥堵已经成为我国大城市的一种社会问题,它与每一个人都息息相关,如何更好地处理这种问题,使其减少对人们出行的影响,成为值得每一个人思考的问题。针对大中型城市中的交通拥堵其中的一种现象进行深入的剖析,系统介绍交通拥堵的成因,有针对性地提出如何改善中小学周边地区交通拥堵现象的一些观点和做法。     

基于职业能力的高职会计实践教学体系的重构

文章通过分析高职会计专业构建实践教学体系的必要性入手，分析会计职业能力的内涵，从会计课程体系、实训项目体系、实训项目教学设计三个方面探索了现代高职会计实践教学体系的构建，拓展会计实践教学的实训资源，完善构建实践教学体系的机制。     

递进式连锁经营管理专业实践教学改革研究——基于加盟创业项目视角

连锁经营管理专业人才培养目标大多定位在一线服务员或基层管理者，所培养的学生必须具备较强的连锁专业能力和创业能力，而大多数高职院校培养出来的学生在这些方面所表现出来的能力却差强人意，尤其是创业能力方面。本文提出将加盟创业项目贯穿于连锁经营管理实践教学全过程，按照“仿真训练-校内孵化-校内模拟-市场全真”四个阶段，形成一个递进式的实践教学流程，从而促使学生的专业能力和创业能力实现递进式提升。     

基于传播模型的非机动车违规过街行为研究

为研究信号交叉口非机动车违规过街行为，选取西安市的7个信号交叉口，通过视频拍摄获取资料，应用复杂网络来分析非机动车网络的结构特征和演化规律.建立了交叉口非机动车网络，基于SI模型的基本思想，提出了非机动车违规过街行为的传播模型.并通过python程序进行模拟分析，在不同的网络结构和不同的传播率下，获取了非机动车违规过街的行为趋势.结果表明：随着等待时间的增加，一旦有骑行者闯红灯，更多的骑行者将加入到违规过街的行列；在内向度和外向度方面，电动自行车均高于普通自行车；非机动车违规行为随着传播率及非机动车流量的增加而增加.     

Design,analysis and performance evaluation of a third order distributed protocol for platooning in the presence of time-varying delays and switching topologies

This paper is concerned with the problem of designing a decentralized consensus protocol for platooning of non-identical vehicles in the presence of heterogeneous time-varying communication delays. The proposed control protocol makes use of a state feedback and to this aim drivetrain dynamics are modeled as third-order linear systems. Necessary and sufficient conditions for convergence and exponential stability, derived by using an appropriate Krasovskii functional, demonstrate the ability of the platoon in reaching the required regime with an exponentially bounded behavior. The proposed LMI-based approach allows to estimate both delay margin and decay rate. Moreover, convergence is proven under switching communication network topologies by means of a Lyapunov-Razumikhin function, and the assessment of a string stable behavior has been also theoretically investigated. High-fidelity simulations with Plexe show the effectiveness of the theoretical results in different driving conditions and in the presence of external disturbances and communication impairment. Different communication channel models are used in the validation stage to further prove robustness of the proposed methodology with respect hard delay and packets losses.     

立交隧道相互作用三维数值模拟与实测对比研究

以温福铁路琯头岭隧道下穿同三高速公路隧道为例,研究新建下穿隧道与既有隧道工程之间相互影响的问题。采用ANSYS有限元软件,模拟上覆公路隧道和下穿铁路隧道的位移和应力变化情况,并与现场监控量测结果对比,得到以下结果:下穿隧道拱顶沉降量较小,水平收敛值较大,下穿隧道立交段拱腰和边墙是需要重点支护的对象;上覆隧道在立交段下沉值变大,变化幅度为仰拱边墙拱腰拱顶,隧道中部和下部水平收敛值变化较大;受下穿隧道开挖影响,立交隧道上覆地层受力产生不均匀变化,造成扭矩存在,地面水平位移整体呈现"8"字形,立交隧道的建设对地层产生了较大的转动扰动。