Twin-Delayed Deep Deterministic Policy Gradient for altitude control of a flying-wing aircraft with an uncertain aerodynamic model

Recent research on the Flying V - a flying-wing long-range passenger aircraft - shows that its airframe design is 25% more aerodynamically efficient than a conventional tube-and-wing airframe. The Flying V is therefore a promising contribution towards reduction in climate impact of long-haul flights. However, some design aspects of the Flying V...

Real-time collision risk based safety management for vessel traffic in busy ports and waterways

Regional risk analysis and management of maritime accidents is one of the fundamental tasks for maritime safety management. With the heavy and complicated maritime traffic in the ports and waterways, accidents, especially ship collision accidents, have been continuously posing threats to the maritime transportation system. To achieve effective...

An epsilon-constraint-based exact multi-objective optimization approach for the ship schedule recovery problem in liner shipping

Time management is crucial for liner shipping services. A variety of unexpected events can disrupt liner shipping schedules. A real-time port capacity analysis and rescheduling the original ship operations would be necessary to counteract the negative effects of such disruptions. Different ship schedule recovery options can be adopted in...

Collision prevention of ship towing operation under environmental disturbance

Towing operations are highly reliant on the experience of the towing operators. Safety concerns arise when towing operations are subjected to environmental disturbances and dynamic traffic conditions. However, a systematic framework and approaches to enhance the safety and automation of towing operations remain lacking. This work proposes a...

Innovations in Coastline Management With Natural and Nature-Based Features (NNBF): Lessons Learned From Three Case Studies

Coastal communities around the world are facing increased coastal flooding and shoreline erosion from factors such as sea-level rise and unsustainable development practices. Coastal engineers and managers often rely on gray infrastructure such as seawalls, levees and breakwaters, but are increasingly seeking to incorporate more sustainable...

Interaction characteristics between multi-port hybrid DC circuit breaker and MVDC distribution system under diversified working conditions

Due to the progressive penetration and usage of renewable sources and loads based on power electronics, medium voltage direct current (MVDC) distribution system is getting broad attention. Direct current circuit breakers (DCCBs) are of vital importance for the reliability and flexibility of power system. With features of low cost and micro...

Automatic Docking for Underactuated Ships Based on Multi-Objective Nonlinear Model Predictive Control

Autonomous shipping refers to the ability of a ship to independently control its own actions while transporting cargo from one port to another, which places higher requirements on ship motion control methods. When a ship enters a port, it is important to ensure that the ship sails from the fairway area to the assigned position at the berth...

A novel bi-level distributed dynamic optimization method of ship fleets energy consumption

The optimization of ship energy consumption is attracting a great deal of attention, as societies seek to save energy and reduce emissions. Shipping companies are more concerned with the energy consumption of a ship fleet, as opposed to that of a single ship. Because the energy consumption of a fleet is influenced by multiple factors...

Relational model of accidents and vessel traffic using AIS Data and GIS: A case study of the Western port of Shenzhen City

Following the growth in global trade activities, vessel traffic has increased dramatically in some busy waterways and ports. However, such increments have made it more complex to manage the regional vessel traffic, which can increase the risk of an accident in the area. To model and analyze the relationship between vessel traffic and maritime...

Coordinated planning of inland vessels for large seaports

Seaports are crucial nodes in international trade and transport. Some of the cargoes arriving at seaports are transshipped to other ports, while others are transported to inland destinations. Every time an inland container vessel enters the port, it calls at many different terminals spread over the port area. Two coordination problems exist in...

A hybrid electromagnetics-circuit simulation method exploiting discontinuous Galerkin time domain finite element method

A hybrid electromagnetics (EM)-circuit simulation method employing the discontinuous Galerkin finite element time domain method (DGFETD) is developed to model single lumped port networks comprised of both linear and non-linear elements. The whole computational domain is split into two subsystems. One is the EM subsystem that is analyzed by the...

AMulti-jurisdiction Case Study of 3D Cadastre in Shenzhen, China as Experiment using the LADM

With the increasing urban population, and the urban exploitation and utilization, especially in the subsurface and the air, various spaces above and below each other are built and belonging to different owners or users. Although the traditional 2D cadastre still plays a dominant role in land administration, urban resource and space management,...