http://hdl.handle.net/10468/5 Wed, 22 May 2013 11:53:43 GMT 2013-05-22T11:53:43Z http://hdl.handle.net/10468/1010 How much wind energy will be curtailed on the 2020 Irish power system? McGarrigle, E. V.; Deane, J. P.; Leahy, Paul G. This paper describes a model of the 2020 Irish electricity system which was developed and solved in a mixed integer programming, unit commitment and economic dispatch tool called PLEXOS. The model includes all generators on the island of Ireland, a simplified representation of the neighbouring British system including proposed wind capacity and interconnectors between the two systems. The level of wind curtailment is determined under varying levels of three influencing factors. The first factor is the amount of offshore wind, the second is the allowed limit of system non-synchronous penetration (SNSP) and the third is inclusion or exclusion of transmission constraints. A binding constraint, resulting from the 2020 EU renewable energy targets, is that 37% of generation comes from wind. When the SNSP limit was increased from 60% to 75% there was a reduction in wind curtailment from 14% to 7%, with a further reduction when the proportion of wind capacity installed offshore was increased. Wind curtailment in the range of SNSP limit of 70-100% is influenced primarily by the inclusion of transmission constraints. Large changes in the dispatch of conventional generators were also evident due to the imposition of SNSP limits and transmission constraints. Mon, 01 Jul 2013 00:00:00 GMT http://hdl.handle.net/10468/1010 2013-07-01T00:00:00Z http://hdl.handle.net/10468/887 Typical tropospheric aerosol backscatter profiles for Southern Ireland: The Cork Raman lidar McAuliffe, Michael A. P.; Ruth, Albert A. A Raman lidar instrument (UCLID) was established at the University College Cork as part of the European lidar network EARLINET. Raman backscatter coefficients, extinction coefficients and lidar ratios were measured within the period 28/08/2010 and 24/04/2011. Typical atmospheric scenarios over Southern Ireland in terms of the aerosol load in the planetary boundary layer are outlined. The lidar ratios found are typical for marine atmospheric condition (lidar ratio ca. 20–25 sr). The height of the planetary boundary layer is below 1000 m and therefore low in comparison to heights found at other lidar sites in Europe. On the 21st of April a large aerosol load was detected, which was assigned to a Saharan dust event based on HYSPLIT trajectories and DREAM forecasts along with the lidar ratio (70 sr) for the period concerned. The dust was found at two heights, pure dust at 2.5 km and dust mixing with pollution from 0.7 to 1.8 km with a lidar ratio of 40–50 sr. Fri, 01 Feb 2013 00:00:00 GMT http://hdl.handle.net/10468/887 2013-02-01T00:00:00Z http://hdl.handle.net/10468/719 A normalization-based approach to the mobility analysis of spatial compliant multi-beam modules Hao, Guangbo; Kong, Xianwen This paper presents a normalization-based approach to the mobility analysis of spatial compliant multi-beam modules to address the dimensional-inhomogeneity issue of motion/load. Firstly, two spatial non-tilted and tilted multi-beam modules, composed of uniform beams with symmetrical cross sections and same length, are proposed. Using a normalization technique, the compliance matrices of these spatial multi-beam modules are derived, from which the DOF (degrees-of-freedom) of the compliant modules can be obtained by direct observation and/or screw representation. The results are compared with those obtained without normalization. It is shown that the DOF of these compliant modules can be identified more easily using the proposed approach than the approach without normalization. Then, two spatial double non-tilted and tilted three-beam modules are proposed and analyzed for potential applications such as acting as building blocks of new compliant manipulators. The normalization-based approach can also be used for the mobility analysis of spatial compliant multi-sheet modules such as the parallelogram module and the four-sheet rotational module and the error analysis of spatial multi-beam modules with beams of compatible length. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10468/719 2013-01-01T00:00:00Z http://hdl.handle.net/10468/905 Planning the deployment of fault-tolerant wireless sensor networks Sitanayah, Lanny Since Wireless Sensor Networks (WSNs) are subject to failures, fault-tolerance becomes an important requirement for many WSN applications. Fault-tolerance can be enabled in different areas of WSN design and operation, including the Medium Access Control (MAC) layer and the initial topology design. To be robust to failures, a MAC protocol must be able to adapt to traffic fluctuations and topology dynamics. We design ER-MAC that can switch from energy-efficient operation in normal monitoring to reliable and fast delivery for emergency monitoring, and vice versa. It also can prioritise high priority packets and guarantee fair packet deliveries from all sensor nodes. Topology design supports fault-tolerance by ensuring that there are alternative acceptable routes to data sinks when failures occur. We provide solutions for four topology planning problems: Additional Relay Placement (ARP), Additional Backup Placement (ABP), Multiple Sink Placement (MSP), and Multiple Sink and Relay Placement (MSRP). Our solutions use a local search technique based on Greedy Randomized Adaptive Search Procedures (GRASP). GRASP-ARP deploys relays for (k,l)-sink-connectivity, where each sensor node must have k vertex-disjoint paths of length ≤ l. To count how many disjoint paths a node has, we propose Counting-Paths. GRASP-ABP deploys fewer relays than GRASP-ARP by focusing only on the most important nodes – those whose failure has the worst effect. To identify such nodes, we define Length-constrained Connectivity and Rerouting Centrality (l-CRC). Greedy-MSP and GRASP-MSP place minimal cost sinks to ensure that each sensor node in the network is double-covered, i.e. has two length-bounded paths to two sinks. Greedy-MSRP and GRASP-MSRP deploy sinks and relays with minimal cost to make the network double-covered and non-critical, i.e. all sensor nodes must have length-bounded alternative paths to sinks when an arbitrary sensor node fails. We then evaluate the fault-tolerance of each topology in data gathering simulations using ER-MAC. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10468/905 2013-01-01T00:00:00Z