Air refueling optimisation for more agile and efficient military deployment operations

Strategic airlift is a crucial capability for any country that wants to protect its global interests around the world. Air refueling may offer more agile and efficient airlift capabilities by increasing cargo aircraft payload and shortening airlift time. We investigated whether air refueling can shorten the total time of an airlift operation and decrease the number of cargo aircraft sorties required in a deployment scenario, especially where the distance between origin and destination is within the range of cargo aircraft. We introduced two mathematical models to compare the total airlift time and number of cargo aircraft required for given origin-destination and tanker base locations and total freight to be moved. We optimised initial cargo and fuel amount for cargo aircraft along with rendezvous point coordinates to minimise total airlift time. We used a numerical example to show that substantial airlift time and cargo aircraft sortie savings are possible through air refueling.

Britain’s European Island-Empire, 1793–1815

This chapter explores the creation and maintenance of Britain’s European island empire during the wars against Revolutionary and Napoleonic France. It traces the initial establishment of island bases in the Mediterranean, North and Baltic Seas, outlining their importance to British trade and strategy. It explains how and why British war aims came to rely on these imperial possessions. Across the Mediterranean, the war came to be defined by the extension of island empires. British victory in 1814 owed much to these islands, lynchpins of its wider European strategy. In northern waters, the island of Heligoland acted as a rendezvous point for trade with the continent, and was a key site from which Napoleon’s ‘Continental System’ could be undermined. Britain’s European island empire proved itself to be a crucial part of Britain’s wider imperial network, and its significance would continue into the nineteenth century and the era of Pax Britannica.

Multicast Optimization And Recovery In Multihoming Environment

Reliability of multicasting is increasingly becoming an important issue as the number of end users continues to grow, their demand for reliable service increases. This thesis proposes a novel algorithm for creating a recovery model while optimizing both inter and intra domain bandwidth. This is achieved by creating a centralized rendezvous point within the intra domain topology. The rendezvous point will create a static multicast tree and it will avoid link congestion during inter-domain link failure. This algorithm also reduces link congestion surrounding the border routers. This is achieved by shifting the root of the multicast tree from the border router to the rendezvous point. This rendezvous point is then selected based on an optimization algorithm to reduce bandwidth congestion. A Steiner tree was used to optimize the intra domain links. The simulation results indicate up to 30% increase over conventional optimization algorithms which do not consider a rendezvous point model.

Multicast Optimization And Recovery In Multihoming Environment

Reliability of multicasting is increasingly becoming an important issue as the number of end users continues to grow, their demand for reliable service increases. This thesis proposes a novel algorithm for creating a recovery model while optimizing both inter and intra domain bandwidth. This is achieved by creating a centralized rendezvous point within the intra domain topology. The rendezvous point will create a static multicast tree and it will avoid link congestion during inter-domain link failure. This algorithm also reduces link congestion surrounding the border routers. This is achieved by shifting the root of the multicast tree from the border router to the rendezvous point. This rendezvous point is then selected based on an optimization algorithm to reduce bandwidth congestion. A Steiner tree was used to optimize the intra domain links. The simulation results indicate up to 30% increase over conventional optimization algorithms which do not consider a rendezvous point model.

Broadcast Event-Triggered Control Scheme for Multi-Agent Rendezvous Problem in a Mixed Communication Environment

This paper addresses the communication issue encountered by a hybrid controller when finding consensus in terms of the rendezvous target point in a broadcast and communication environment. This issue may result in a high level of computation and the utilization of agent resources when a continuous communication is required by agents to meet convergence requirements. Thus, an event-triggered system was integrated into the design of a broadcast and distributed consensus linear controller using the simultaneous perturbation stochastic algorithm (SPSA). The agent’s movement towards the rendezvous point is based on the broadcast value, whereas the next agent’s state position depends on the distributed local controller output. The communication error obtained during communication between the agent and neighbors is only added to the gradient approximation error of the SPSA if the event-triggered function is violated. As a result, in our model, the number of channel utilizations was lower and the agents’ performances were preserved. The efficiencies and effectiveness of the proposed controller have been compared with the traditional sampling broadcast time-triggered (BTT) approach. The time and iterations required by the broadcast event-triggered (BET) system were less than 40.42% and 21% on average as compared to BTT. The trajectory was not the same—the BET showed scattered movements at the initial stage, whereas BTT showed a linear movement. In terms of the number of channels, 28.91% of channels were preserved during the few hundred iterations. Consequently, a variety of hybrid controllers with event-triggered mechanisms can be proposed for other multi-agent motion coordination tasks.