Guided wave inspection is a form of ultrasonic testing used for non-destructive testing (NDT). Guided waves are capable of propagating long distances bounded by the geometries of the specimen, such as pipes and plates. The technique is commercially used to detect defects in pipelines and is capable of a full volumetric screening many metres (often up to around 100m) from one location. Fundamental axisymmetric wave modes are used to inspect pipelines and are used to quantify defects and features. However, as the technology has progressed, a demand for improving defect sensitivity, spatial resolution and developing the technology into new fields has been recognised. Operating at medium range frequencies is one possibility that could provide the increase in defect sensitivity and spatial resolution required that may not be achieved at low range frequencies. The use of higher order wave modes could also provide additional information useful for defect sizing. Guided wave inspection is a complex ultrasonic technique due to the many wave modes that exist and testing at medium range frequencies requires some challenges to be overcome. The research presented here investigates the potential of using the second order torsional wave mode at medium range frequencies and provides a new sizing technique that for some applications is likely to offer advancement in guided wave inspection and monitoring. The approach firstly included the design and implementation of a setup for analysing the complex signal responses in order to access the higher order torsional wave mode T(0,2) for defect sizing. An efficient method of using FEA has been presented using segmented models to provide the capability of analysing defects with small increment changes that could not be achieved using a full 3D model of the pipe. Using a pipe segment to virtually represent the full pipe also allowed small changes in defect size to be investigated, which would otherwise be extremely difficult to accurately machine experimentally. The FEA modelling technique is also based on broadband signals in comparison to the conventional approach of using narrowband signals and is capable of obtaining a wide frequency spectrum from one model, which significantly reduces the number of models needed to conduct a frequency analysis. Following on from this work, a high density transducer array was developed and compared against a conventional transducer array used in guided wave inspection for the purpose of medium range frequency inspection, which can also be applied to conventional low range frequency inspection. Finally, a new defect sizing method using T(0,2) is presented, which is capable of predicting the depth using peak amplitude responses from spectral analysis and by comparing this to the cut-off frequency of the remaining wall thickness of the defect. The technique has the potential to improve defect sizing, defect sensitivity, increase spatial resolution, and increase the performance of medium range inspection.

It is expected that increasing amounts of distributed generation (DG) will be connected to the power system in the future. Advances in technology, deregulation in the market and the changes brought about by the government in many countries to end the monopoly of the vertically integrated power utilities led to the birth of this new technology. The other incentive being the alternative energy sources which are becoming more cost effective. Although there are many advantages with the interconnection of the DG into the network, there are many problems that it brings with its interconnection. There are many issues to be considered for the interconnection of DG?s, like the sizing and siting of the DG. The size and site of the DG will have an effect on the voltages and operations of the distribution power system. Since it is necessary that the voltages be within a specified limit, this problem of the siting and sizing of the DG has taken top priority. This thesis discusses a procedure for evaluating the impact of the site, size of the DG and also a change in the loading conditions of the system before and after the reconfiguration of the system due to the fault. This contingency analysis work is validated using the I 13 and I 37 node distribution feeder. Many feasible combinations of the size and site of a DG are analyzed, which resulted in large number of data, while the load flow is run for each feasible combination. The results and trends are presented.

In this work, a size optimization approach for utility-scale solar photovoltaic (PV) systems is proposed. The purpose of the method is to determine the optimal solar energy generation capacity and optimal location by the minimizing total system cost subject to the constraint that the system reliability requirements. Due to the stochastic characteristic of the solar irradiation, the reliability performance of a power system with PV generation is quite different from the one with only conventional generation. Basically, generation adequacy level of power systems containing solar energy is evaluated by reliability assessment and the most widely used reliability index is the loss of load probability (LOLP). The value of LOLP depends on various factors such as power output of the PV system, outage rate of generating facilities and the system load profile. To obtain the LOLP, the Monte Carlo method is applied to simulate the reliability performance of the solar penetrated power system. The total system cost model consists of the system installation cost, mitigation cost, and saving fuel and operation cost. Mitigation cost is accomplished with N-1 contingency analysis. The cost function minimization process is implemented in Genetic Algorithm toolbox, which has the ability to search the global optimum with relative computational simplicity. / Master of Science

Hardware sizing has come to play an important role when designing and implementing business critical applications because it is crucial that the existing or defined business and application requirements are interpreted into an appropriate hardware configuration. If it is not done correctly, it may destabilize the environment which means interruptions and unplanned downtimes that in turn will cause business loosing not only vital revenue but also customer confidence in the process. This is one of the reasons for why hardware sizing has become a discipline of its own and as such, each combination of workload and hardware configuration is treated differently. Many application vendors have their own set of tools and recommendations to perform the sizing. Once the sizing is performed, the results can be mapped to hardware that is already benchmarked. This also means the hardware can be configured specially to support the application workload in question. It also implies that sizing is one of the major activities when creating a technical architecture where it is used to select the right hardware.   The purpose of this document is to perform a complete sizing exercise based on the requirements for a mission critical business application and then translate them into an appropriate hardware configuration. Furthermore, a set of sizing methodologies and tools are analyzed in detail as well in order to give an as vendor neutral view as possible. Specific requirements such as high availability, scalability and other important areas are also taken into consideration when designing and creating the hardware architecture.