Development of a novel forward dynamic programming method for weather routing

This paper presents a novel forward dynamic programming method for weather routing to minimise ship fuel consumption during a voyage. Compared with traditional weather routing methods which only optimise the ship's heading, while the engine power or propeller rotation speed is set as a constant throughout the voyage, this new method considers both the ship power settings and heading controls. A float state technique is used to reduce the iterations required during optimisation and thus save computation time. This new method could lead to quasiglobal optimal routing in comparison with the traditional weather routing methods

Ophthalmological Manifestations of Oculocutaneous and Ocular Albinism: Current Perspectives

Albinism describes a heterogeneous group of genetically determined disorders characterized by disrupted synthesis of melanin and a range of developmental ocular abnormalities. The main ocular features common to both oculocutaneous albinism (OCA), and ocular albinism (OA) include reduced visual acuity, refractive errors, foveal hypoplasia, congenital nystagmus, iris and fundus hypopigmentation and visual pathway misrouting, but clinical signs vary and there is phenotypic overlap with other pathologies. This study reviews the prevalence, genetics and ocular manifestations of OCA and OA, including abnormal development of the optic chiasm. The role of visual electrophysiology in the detection of chiasmal dysfunction and visual pathway misrouting is emphasized, highlighting how age-associated changes in visual evoked potential (VEP) test results must be considered to enable accurate diagnosis, and illustrated further by the inclusion of novel VEP data in genetically confirmed cases. Differential diagnosis is considered in the context of suspected retinal and other disorders, including rare syndromes that may masquerade as albinism

Fuel Saving in Coastal Areas: A Case Study of the Oslo Fjord

Fossil fuels such as marine diesel oil (MDO) account for a significant part of the shipping industry’s total operating costs and have a certain negative impact on the environment. Maritime transport emits around 1000 million tonnes of CO2 annually and is responsible for about 2.5% of global greenhouse gas emissions. To focus on fuel saving is therefore important for both economic and environmental reasons. It is indicative that ship owners are now using weather routeing to save fuel and reduce emissions, particularly on long passages. In coastal areas, navigation is limited by traffic rules. This study examines whether fuel consumption can be reduced with current routeing in confined coastal areas, in this case a relatively short voyage in the Oslo Fjord, Norway. An advanced bridge simulator is used, where different current fields from a high-resolution ocean model are implemented. The results reveal that if the voyage is conducted on a typical field with following currents, instead of a typical counter current field, the travel time will be reduced by 12% for a typical vessel with speed through water set to 16.7 knots. On following currents, the vessel speed can be reduced to 15.7 knots and the voyage is completed within the same time as if no currents are present. This implies approximately a 15% reduction in fuel consumption for the vessel tested. The results also reveal that fuel consumption can be reduced if the vessel is operated within most favourable or least unfavourable currents inside the main traffic lanes