Now showing 1 - 9 of 9
  • Publication
    Dynamic Non-DGPS positional accuracy performance between recreational and professional GPS receivers
    (Taylor and Francis, 2007-09-25) ; ;
    The purpose of this study was to measure and evaluate the dynamic non-differential positional accuracy of two global positioning systems (GPS) receivers. The two receivers used were the Trimble GeoXT handheld and the Garmin GPSMAP 76. Both units are single-frequency, twelve-channel GPS receivers. The units were tested for horizontal root mean square (HRMS) positional accuracy without real–time differential correction in the dynamic mode by recording the movements of an articulated truck across the Irish road network. The units were operated with their external magnetic-mounted antenna. The two antennas were fitted side by side to the cab of the truck. The articulated truck was a DAF XF95 model, 4 × 2 tractor unit with a tri-axle road-friendly air suspension Fruehauf curtain side trailer measuring 13.6 metres (m) in length and 4.2 m in height from the ground. Routes were travelled from the east of Ireland to the south and south–west of the country on six separate occasions during August 2005 giving a total of six consecutive routes. Over 50 hours of data, totalling approximately 6000 data points, sampled at 30 second intervals, were recorded for each of the GPS units. Of these 50 hours, over 30 hours were recorded as dynamic points, totalling approximately 4000 sampling points. The HRMS accuracy was measured at a confidence level of 63%. The HRMS results for the Trimble GeoXT ranged from about 6.9 m for the Cork 1 route to 3.2 m for the Cork 2 route (Table 1). Results for the Garmin GPSMAP76 varied from a much higher value of about 43.0 m for the Limerick 3 route to 56.9 m for the Cork 2 route (Table 1). With this highly variable level of positional accuracy between the two GPS units, it is clear which receiver unit can best be used for professional GPS data collection (Trimble GeoXT) and which is suitable for use as a recreational device (Garmin GPSMAP 76). The option to collect field data using inexpensive recreational GPS units may be sufficient for outdoor enthusiasts who simply require an occasional location fix of moderate (even uncertain) accuracy, but it is unlikely to be sufficient for the Geographical Information Systems (GIS) professional who requires consistently accurate locations of objects, lines and polygons so that data layers can be overlayed within a GIS. A position fix that is tens of metres in error can lead to distorted spatial data and hence incorrect decision making. In fact, for some applications, a very inaccurate position could be worse than no position fix at all.
      428Scopus© Citations 2
  • Publication
    An economic assessment of potential ethanol production pathways in Ireland
    An economic assessment was conducted on five biomass-to-ethanol production pathways utilising the feedstock: wheat, triticale, sugarbeet, miscanthus and straw. The analysis includes the costs and margins for all the stakeholders along the economic chain. This analysis reveals that under current market situations in Ireland, the production of ethanol under the same tax regime as petrol makes it difficult to compete against that fuel, with tax breaks, however, it can compete against petrol. On the other hand, even under favourable tax breaks it will be difficult for indigenously produced ethanol to compete against cheaper sources of imported ethanol. Therefore, the current transport fuel market has no economic reason to consume indigenously produced ethanol made from the indigenously grown feedstock analysed at a price that reflects all the stakeholders’ costs. To deliver a significant penetration of indigenous ethanol into the market would require some form of compulsory inclusion or else considerable financial supports to feedstock and ethanol producers.
      734Scopus© Citations 12
  • Publication
    Timber haulage routing in Ireland: an analysis using GIS and GPS
    Since the late 1980s, GIS (geographical information systems) have evolved to fully enable the range of capabilities needed in transportation routing, research and management. The objective of this paper was to analyse the designation of articulated haulage routes from one central depot to various destinations around the country of Ireland in terms of road class, distance, speed and travel time and compare the results with simulated routes generated within the GIS. The analysis incorporated a digitised road map of Ireland, where the GPS routes could be overlayed, together with ESRI’s (Environmental Systems Research Institute Inc., CA) ArcGIS software. The ArcInfo Network Analyst Tool (NAT) was used to compare routes generated by Dijkstra’s routing algorithm with the actual GPS routes in terms of road classifications, distance, speed and journey time of the route selected i.e. 'destination planning', a term used here to describe the shortest optimum route based on road class, road length, road speed and route journey time. Results showed that the shortest path (in terms of distance) determined by the NAT did not replicate the actual GPS routes. However, when the NAT was manipulated and used to determine the routes based on road classes i.e. routing to higher classes of roads and not distance (by applying a cost weighting within the geometric network), then the GPS routes were over 90% similar with what was modelled within the GIS. This may allow the GIS alone to be used in the network analysis of truck routing and in particular, timber truck routing from forest harvesting site to destination timber mill in Ireland and incorporate the use of GPS for other advantages such as real-time tracking and monitoring of timber movement.
      829Scopus© Citations 49
  • Publication
    Minimizing Distress on Flexible Pavements Using Variable Tire Pressure
    (American Society of Civil Engineers, 2001-06) ; ; ;
    The potential of variable tire pressure technology to minimize distress on flexible pavements with thin asphalt surfacing layers and peat soil subgrade was evaluated using in-situ stress-strain data. Pavement interfacial strains and corresponding subgrade stresses imposed by a three-axle truck were measured and used to estimate the fatigue life of the surfacing layer. Three levels of truck wheel loads in combination with four tire inflation pressures (350, 490, 630, and 770 kPa) were used to evaluate the potential distress by the single steering wheel and rear dual wheels in tandem. Results suggest that lateral strain due to the single steering wheel is the most critical to fatigue failure, which is influenced by the viscoelastic nature of asphalt, and therefore truck speed and axle configuration are important. Lower tire pressures increased the fatigue life of the surfacing layer with respect to the rear dual wheels and the steering wheel by up to 200 and 300%, respectively. Haulage trucks with systems for managing variable tire pressure such as the central tire inflation systems may therefore enhance the serviceability of pavements overlying peat or other soft soil foundations.
    Scopus© Citations 51  880
  • Publication
    Performance Accuracy Of Low‐Cost Dynamic Non‐Differential GPS on Articulated Trucks
    (American Society of Agricultural and Biological Engineers, 2007) ; ;
    The purpose of this study was to evaluate the positional accuracy of dynamic non‐differential global positioning system (Non DGPS) for tracking articulated trucks across the Irish road network. The study was carried out using a Trimble GeoXT handheld GPS unit in the non‐differential mode. The data was logged through Environmental Systems Research Institute (ESRI) ArcPad software. The GPS unit was operated in conjunction with an external magnetic antenna that was fitted to the cab of the articulated truck. The articulated truck was a DAF 95XF model, 4×2 tractor unit with a Fruehauf manufactured tri‐axle curtain side trailer measuring 13.6 m in length and 4.2 m from the ground. Routes were traveled from the east of Ireland to the south and southwest of the country on three separate occasions during August 2005 giving a total of six consecutive routes. Over 50 h of data, totaling approximately 6,000 data points, sampled at 30‐s intervals were recorded. Of these 50 h, over 30 h were recorded as dynamic points totaling approximately 4,000 sampling points. The Horizontal Root Mean Square (HRMS) accuracy was measured at a confidence of 63%. Results ranged from 6.9 m for the Cork 1 route to 3.2 m for the Cork 2 route. With this high level of positional accuracy available, it will be more than adequate to use low‐cost non‐differential GPS to track position and movement of timber trucks across the Irish public road network.
      470
  • Publication
    Monitoring environmental parameters in poultry production facilities
    (Institute for Process and Particle Engineering, Graz University of Technology, Austria, 2013-04) ; ; ;
    Increases in fuel and feed prices are placing a significant burden on the poultry industry in Ireland and worldwide. For producers to meet their financial targets, increased performance and output is a key issue, now more than ever. To optimise performance in broiler production houses, the effect of environmental and air quality parameters on bird performance and energy consumption must be known to allow farmers make informed management decisions. This paper concentrates on the application precision livestock farming sensors to develop recommendations for improved bird performance and energy consumption in broiler production farms in Ireland.   Air temperature, relative humidity, light, air speed and air quality (in particular CO2 and NH3 concentrations) are identified as important parameters for improving bird performance and energy consumption in broiler production houses. Several of these parameters (temperature, relative humidity, CO2 and NH3) were monitored on two farms during the study over the initial 2 weeks of the production cycle. Air quality was often overlooked during the production process, as farmers struggled to limit high heating and feed costs. However, elevated levels of CO2 (>3000 ppm) did not appear to affect broiler growth rates. Additionally, a strong correlation was observed between relative humidity and NH3 (R2 = 0.86 - 0.92). Producers tend to use relative humidity as an indication for NH3 levels and the research shown in this study confirms the close relationship between the two parameters. It is recommended that further data should be gathered from producing units and novel performance technologies should also be investigated.
      5654
  • Publication
    Development of a Spatial Decision Support System (SDSS) for Route Costing Calculations within the Irish Timber Haulage Sector
    (American Society of Agricultural and Biological Engineers, 2008) ; ;
    Since the 1970s, decision support systems (DSS) have become popular as computer technology has developed. A DSS aims to support the solving of specific problems with both human and computer techniques. The purpose of this research was to design and develop a DSS for application to cost and revenue calculations of contracted timber haulage in Ireland. The DSS allows the costs and revenue of timber haulage to be calculated on a daily basis and on a route-specific basis. This implies that the user interface allows certain criteria to be selected, such as truck configuration, truck model, engine size, horsepower, and design gross vehicle weight. Both the revenue and running costs are directly related to the payload weight and the distance traveled. To generate the routes traveled and provide a sophisticated interface for spatial road map information, a Geographic Information System (GIS) was used; ESRI's ArcView 8.3 provides its own application programming in the form of Visual Basic for Applications (VBA).
      577
  • Publication
    A preliminary investigation on face recognition as a biometric identifier of sheep
    (The American Society of Agricultural and Biological Engineers, 2007) ; ; ; ;
    The suitability of face recognition was investigated as a biometric-based identifier for sheep using a holistic analysis of face images by the independent components technique. Algorithm training was performed independently on several normalized face images from 50 sheep (sets of two, three, and four training images per sheep). The performance of this technique was assessed on a separate set of images (three normalized face images per sheep) using the cosine distance classifier. When 180 to 200 components were extracted, the recognition rate was as high as 95.3% to 96%. As expected, fewer independent components reduced the recognition rate, while a higher number of training images per sheep improved it. Although our results have demonstrated the potential of face recognition as a non-invasive, inexpensive, and accurate novel biometric identifier of sheep, further work should aim at improving recognition rates on a larger set of sheep faces.
      916
  • Publication
    Autonomous Winter Wheat Variety Selection System
    (Journal of Advanced Agricultural Technologies, 2017-06) ; ;
    Public and private organizations have been investing significant financial and human resources to develop crop varieties suitable for different commercial destinations, regional characteristics and agronomic factors. The high number of variables and consequent complex analysis are factors that make the task of selecting a specific crop variety, that best fulfill the particularities of a given farm, a challenging one. In this scenario, this work proposes a ranking/decision method to deal with the stochastic problem of select a winter wheat variety, taking into account the random factors that influence in the specific decision. The system evaluates the commercial destination, site-specific and agronomic importance of varieties treats, such as resistance to diseases and lodging, to output a list of best winter wheat varieties choices, for a particular situation. The system's accuracy has been verified by experts of crop science, where a number of random outcomes were tested against specialist opinion.
      408