大吨位沉船打捞多体系统耦合水动力特性研究

双驳船抬吊法是大吨位沉船打捞中主要采用方法之一。两艘驳船、难船构成的系统具有尺度大、间距小等特点,波浪环境形成复杂水动力耦合效应,基于势流理论,增加人工阻尼修正其粘性影响,利用AQWA软件开展单驳船、两驳船约束其一、两驳船耦合三种状态多体系统水动力数值预报研究,重点分析不同状态下驳船运动响应及波浪载荷,探讨了驳船约束模式、浪向角及周期对驳船水动力影响规律,探明了浪向角与周期对驳船耦合水动力及运动响应不利干扰,对指导沉船打捞多体系统的空间布局与作业海况具有重要意义。     

江海直达驳的实船营运试验分析

该文就江海直达驳矿石运输系统的可行性,以实船作营运模拟试验,从试验结果的分析中提出了开发江海直达驳船型等应注意的问题。     

Comparison of energy demands of drone-based and ground-based parcel delivery services

Drones are one of the most intensively studied technologies in logistics in recent years. They combine technological features matching current trends in transport industry and society like autonomy, flexibility, and agility. Among the various concepts for using drones in logistics, parcel delivery is one of the most popular application scenarios. Companies like Amazon test drones particularly for last-mile delivery intending to achieve both reducing total cost and increasing customer satisfaction by fast deliveries. As drones are electric vehicles, they are also often claimed to be an eco-friendly mean of transportation.In this paper an energy consumption model for drones is proposed to describe the energy demand for drone deliveries depending on environmental conditions and the flight pattern. The model is used to simulate the energy demand of a stationary parcel delivery system which serves a set customers from a depot. The energy consumed by drones is compared to the energy demand of Diesel trucks and electric trucks serving the same customers from the same depot.The results indicate that switching to a solely drone-based parcel delivery system is not worthwhile from an energetic perspective in most scenarios. A stationary drone-based parcel delivery system requires more energy than a truck-based parcel delivery system particularly in urban areas where customer density is high and truck tours are comparatively short. In rather rural settings with long distances between customers, a drone-based parcel delivery system creates an energy demand comparable to a parcel delivery system with electric trucks provided environmental conditions are moderate.     

Modelling energy consumption of electric freight vehicles in urban pickup/delivery operations: analysis and estimation on a real-world dataset

Electric Freight Vehicles (EFVs) are a promising and increasingly popular alternative to conventional trucks in urban pickup/delivery operations. A key concerned research topic is to develop trip-based Tank-to-Wheel (TTW) analyses/models for EFVs energy consumption: notably, there are just a few studies in this area. Leveraging an earlier research on passenger electric vehicles, this paper aims at filling this gap by proposing a microscopic backward highly-resolved power-based EFVs energy consumption model (EFVs-ECM). The model is estimated and validated against real-world data, collected on a fleet of five EFVs in the city centre of Rome, for a total of 144 observed trips between subsequent pickup/delivery stops. Different model specifications are tested and contrasted, with promising results, in line with previous findings on electric passenger vehicles.     

深水航道BIM设计成果交付平台研发与应用

针对深水航道BIM应用存在多源数据文件格式难以统一、大范围场景与小型构件并存难以展现、成果交付效率低下等问题,进行深水航道工程BIM设计成果交付平台的研究。采用统一建模标准、轻量化BIM模型、开发应用平台等方法,解决了该类工程成果交付难的问题。研究成果表明深水航道较其他工程更具专业独特性,须定制适合其专业模型特征与特性展示方式的BIM应用平台,方能实现基础设施领域深水航道BIM设计成果的有效交付。研究成果已应用于连云港港30万吨级航道二期工程并取得良好效果,为该行业BIM全流程的后续应用打下理论基础。     

Vehicle routing with roaming delivery locations

We propose the vehicle routing problem with roaming delivery locations (VRPRDL) to model an innovation in last-mile delivery where a customer’s order is delivered to the trunk of his car. We develop construction and improvement heuristics for the VRPRDL based on two problem-specific techniques: (1) efficiently optimizing the delivery locations for a fixed customer delivery sequence and (2) efficiently switching a predecessor’s or successor’s delivery location during the insertion or deletion of a customer in a route. Furthermore, we conduct an extensive computation study to assess and quantify the benefits of trunk delivery in a variety of settings. The study reveals that a significant reduction in total distance travelled can be achieved, especially when trunk delivery is combined with traditional home delivery, which has both economic and environmental benefits.     

Reducing carbon emission of pickup and delivery using integrated scheduling

Integrated scheduling is a powerful way to reduce carbon emission of pickup and delivery because the vehicle loading efficiency can be improved. Our study investigates theoretically the potential carbon emission reduction brought by integrated scheduling, and develops the upper and lower bounds. To demonstrate the practical advantage of carbon emission reduction brought by integrated scheduling, we use the real application of pickup and delivery, i.e., “picking up and delivering customers to airport” (PDCA). Using based-on-set-partitioning formulation, we accurately obtain the minimal carbon emissions of non-integrated scheduling and integrated scheduling. We conclude that integrated scheduling reduces carbon emission by approximate 10.8%. However, the cost in integrated scheduling may be more than before, which causes a company unwilling to accept integrated scheduling. The acceptable integrated scheduling is proposed. We identify the situations under which carbon emission can be efficiently reduced in acceptable integrated scheduling based on the extensive experiments of PDCA.     

基于车流结构的计重收费可变附加值模型研究

计重收费是一种最主要的货车收费形式。为了分析货车流对公路交通的影响,均衡货车交通量的时空分布,需对传统计重收费方式进行优化。分析车流结构对公路使用寿命、通行能力、交通安全的影响,建立可变附加值模型,并分别对按车型收费、轮轴收费、计重收费、可变附加值计重收费4种方式在不同车流结构或货车总质量下的100km收费额度进行对比分析。分析表明,若按车型收费,在货车总质量和流量较小的情况下适用性较好;而按可变附加值计重收费则可更加合理地反映货车对道路及交通流的影响。     

"LUCKY ANGEL"半潜驳的锚泊设计

近年来随着海上工程项目的增多,人们对半潜驳的需求也日益增加,然而要使半潜驳真正发挥其部分潜入水中以便承载结构物的作用,合理有效的锚泊定位是不可缺少的一部分。该文详细介绍了“LUCKY AN-GEL”半潜驳的锚泊设计过程及分析方法,该方法不仅适用于半潜驳,也可以应用于类似的工程船。     

有限元程序在重特大件运输中的运用

以一艘载重15 000 t的大型半潜式甲板驳船(重任1602)装载4个超大型沉箱为例,采用直接计算法,利用国际上相关成熟的有限元程序(Ansys),进行局部结构强度计算,并对计算结果进行了分析和评估,提出了操作和结构加强建议。