Now showing 1 - 5 of 5
  • Publication
    Analysis of End-Stop Parameters on the Performance of Heaving Point Absorber Wave Energy Convertors
    Wave energy converters (WEC) have the potential to generate a sizeable proportion of Ireland’s energy needs. Although there has been a great deal of research into WEC technology, no commercial devices exist at this time. One reason for this, has been underestimating the forces involved in the marine environment, and thus under designing components, especially power take off (PTO) systems. End stops are a crucial component of all moving body converters, which have rigid connections to PTOs. They are designed to protect the PTO mechanism by restricting the allowable travel distance. End stops, although vital components of WEC technology limit energy generation and thus must be taken into account in initial design. In this paper, a torus shaped point absorber moving against a monopile is numerically modelled in operational conditions using combined potential flow boundary element method and modified Morison's equation viscous drag. Two torus geometries are modelled, varying the radius and draft. The effect of various end-stop parameters on PTO forces and average annual energy generation are analysed. These parameters being; WEC travel distance, end stop distance and stiffness. Two separate Irish sites are analysed, a high energy site off the west coast and a medium energy site off the south coast. This paper aids WEC development by describing the performance effects of end stop design.
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  • Publication
    Health impacts of cycling in Dublin on individual cyclists and on the local population
    There is an emerging consensus that personal and societal health benefits in cycling largely outweigh the risks. However, there exists limited research into the health impacts experienced by individuals who take up cycling or the marginal societal benefits resulting from incremental uptake of cycling. This paper models and estimates the health impacts of individuals in Dublin taking up cycling. The paper utilizes the 2011 census data of Ireland and a Burden of Disease (BOD) approach is used to estimate health impacts on the individuals taking up cycling for their regular commute and on the rest of the local population separately. The health impact to an individual changing from private car to cycling ranged from a benefit of 0.033 Disability Adjusted Life Years (DALYs)/year to a loss of 0.003 DALYs/year. The marginal health impact to the local population ranged from no change to a benefit of 0.006 DALYs/year. Increases in cycling have a consistently positive impact on the health of the local population, regardless of the current modal split. The net expected health impacts to the individual cyclists are also positive in most cases. However, for some individuals in the 20–29 age group, the expected health impact may be small to negative, mainly due to a higher traffic collision risk. Where total impacts of scenarios are modelled the potential negative health impacts to some individuals may be masked by the overall positive health benefits of cycling to the local population. When promoting cycling as an alternative to driving to improve population health impacts, the risks to some cyclists should be managed and mitigated through safe road systems approaches.
    Scopus© Citations 14  364
  • Publication
    Dear Diary: Reports of Uncontrolled Experiments in Cork
    (Irish Transport Research Network, 2017-08-29) ; ; ; ;
    Perceived risks of cyclists is a deterrent for increasing cycling activity in a mixed mode network. This fact is particularly relevant for networks where cycling is becoming popular. This paper presents an uncontrolled study in Cork where a number of cyclists kept a diary log of incidents and perceptions of risk for a period of time while traveling. The risk ratings were carried out based on a 10 point scale and the results of this study avoid the Hawthrone Effect. The cyclists provided self-reported data on risk ratings related for a range of routes in Cork and this paper forms a first evidence base around the perception of safety of cyclists in Cork. Interactions with motorists, conflict points, condition of the infrastructure and other factors were investigated and the study attempts to provide a better insight to the perceived safety of cyclists in a city where interest and investment around cycling is on the rise. Several consistent themes emerged from the diary entries. These include, lack of awareness, lack of respect towards cyclists in a mixed mode network, lack of space and time given to the cyclists for manoeuvre, the state of cycling facilities, motor vehicles cutting across cyclists and late or no indication by motorists. The study provides insight to cyclist-vehicle interaction in an emerging cycling network and encourages further research in the area of culpability and risk ratings.
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  • Publication
    Protocols for Image Processing based Underwater Inspection of Infrastructure Elements
    Image processing can be an important tool for inspecting underwater infrastructure elements like bridge piers and pile wharves. Underwater inspection often relies on visual descriptions of divers who are not necessarily trained in specifics of structural degradation and the information may often be vague, prone to error or open to significant variation of interpretation. Underwater vehicles, on the other hand can be quite expensive to deal with for such inspections. Additionally, there is now significant encouragement globally towards the deployment of more offshore renewable wind turbines and wave devices and the requirement for underwater inspection can be expected to increase significantly in the coming years. While the merit of image processing based assessment of the condition of underwater structures is understood to a certain degree, there is no existing protocol on such image based methods. This paper discusses and describes an image processing protocol for underwater inspection of structures. A stereo imaging image processing method is considered in this regard and protocols are suggested for image storage, imaging, diving, and inspection. A combined underwater imaging protocol is finally presented which can be used for a variety of situations within a range of image scenes and environmental conditions affecting the imaging conditions. An example of detecting marine growth is presented of a structure in Cork Harbour, Ireland.
      259Scopus© Citations 5
  • Publication
    Inspection of Cycleways with DataCycle - Preliminary Results
    (Irish Transport Research Network, 2017-08-29) ; ; ;
    This paper presents the first inspection results using DataCycle, a first maintenance management system for cycleways in Ireland. DataCycle provides a system of inspection and assessment of cycleways, along with an inspection manual. As a first application of DataCycle, the inspection method and assessment is applied to two different cycling routes in Cork, Ireland. The first route is the Passage West to Rochestown cycle route, which has been developed along an old disused rail line and is in an area where cycling and walking for both leisure and commuting is possible. The second route is the Cork City to Ballincollig Cycleway. This is the main cyclist commuter route between Ballincollig and the city centre. It covers a distance of 6.4km. The cycle route is comprised of a segregated roadside cycleway and a shared footpath and cycle route in parts. The assessments compare and contrast these two distinct routes and demonstrates how a Cycleway Management System(CMS) in the form of DataCycle can be beneficial to managing this asset in a targeted manner. The ease of use, ability to align with existing maintenance management systems and the possibility of upscaling the system is highlighted. The results present typical outputs for some of the routes inspected implementing the cycleway management system with suggested intervention options. The work demonstrates how the developed system can be easily implemented for cycleways and encourages the use of such centralised maintenance system for cycleways throughout the country. A substantial inspection database for cycling facilities should allow for implementation of asset management methodologies, including cross-asset management formats.
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