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Skill-based robot programming is commonly used in manufacturing automation to provide non-expert users with flexible ways to specify various robot tasks in the robot workspace. However, non-experts typically are unaware of the capability of the robot system, such as the applicability and the quality of the skill and parameters they specify. Users may have to wait until runtime to find inappropriate parameter settings and other errors in platform-specific specifications, making robot programming difficult. How to develop a robot programming system that can allow non-expert users to specify robot tasks with only basic knowledge of the robot's capability during task programming is a significant problem. Although existing works tackle this problem by pre-embedding experts' knowledge of the robot skills and system and only expose what users can specify in the programming, incorporating the sensing-based capability of the robot system is not well studied. Without sufficient ability for detection or monitoring, a robot system may be late in capturing execution faults that could drastically reduce performance or cause a catastrophic system crash. In this dissertation, we shall address the above issue by the following. (1) We introduce a programming system framework that incorporates the sensing-based capability of the robot system to generate guidance suggestions in assisting non-expert users in specifying effective robot programs. (2) We develop several components for the system. LASSO is a programming tool designed to construct spatial information of target objects for robot skills. The SQRP system extracts the spatial and temporal requirements from a robot skill to compute sensing-based capability. We further develop the SQGS system for users to define fine-grained requirements for sensing-based capability and provide guidance suggestions for parameter selection and environment reconfiguration. Ultimately, we develop the SensingRG system to extend our framework to include more complicated robot skills and tasks. (3) We evaluate the efficacy of our system framework by conducting a user study on a real-world robot task and demonstrate our framework on a real-world robot toy assembly task to show generalizability.

In comparison with PWM converters, resonant converters are gaining increasing popularity for cases in which efficiency and power density are at a premium. However, the lack of an accurate small-signal model has become an impediment to performance optimization. Many modeling attempts have been made to date. Besides the discrete time-domain modeling, most continuous-time modeling approaches are based on fundamental approximation, and are thus unable to provide sufficient accuracy for practical use. An equivalent circuit model was proposed by Yang, which works well for series resonant converters (SRCs) with high Q (quality factor), but which is inadequate for LLC resonant converters. Furthermore, the model is rather complicated, with system orders that are as high as five and seven for the SRC and LLC converter, respectively. The crux of the modeling difficulty is due to the underlying assumption based on the use of a band-pass filter for the resonant tank in conjunction with a low-pass output filter, which is not the case for most practical applications. The matter is further complicated by the presence of a rectifier, which is a nonlinearity that mixes and matches the original modulation frequency. Thus, the modulation signal becomes intractable when using a frequency-domain modeling approach. This dissertation proposes an extended describing function modeling that is based on a Fourier analysis on the continuous-time-domain waveforms. Therefore, all important contributions from harmonics are taken into account. This modeling approach is demonstrated on the frequency-controlled SRC and LLC converters. The modeling is further extended to, with great accuracy, a charge-controlled LLC converter. In the case of frequency control, a simple third-order equivalent circuit model is provided with high accuracy up to half of the switching frequency. The simplified low-frequency model consists of a double pole and a pair of right-half-plane (RHP) zeros. The double pole, when operated at a high switching frequency, manifests the property of a well-known beat frequency between the switching frequency and the resonant frequency. As the switching frequency approaches the resonant frequency of the tank, a new pair of poles is formed, representing the interaction of the resonant tank and the output filter. The pair of RHP zeros, which contributes to additional phase delay, was not recognized in earlier modeling attempts. In the case of charge control, a simple second-order equivalent circuit model is provided. With capacitor voltage feedback, the order of the system is reduced. Consequently, the resonant tank behaves as an equivalent current source and the tank property is characterized by a single pole. The other low-frequency pole represents the output capacitor and the load. However, the capacitor voltage feedback cannot eliminate the high-frequency poles and the RHP zeros. These RHP zeros may be an impediment for high-bandwidth design if not properly treated. Based on the proposed model, these unwanted RHP zeros can be mitigated by either changing the resonant tank design or by proper feedback compensation. The accurate model is essential for a high-performance high-bandwidth LLC converter.

Since the modern Refugee and Humanitarian Programme began in 1977, around 14,000 refugees have been granted residency in Australia every year, with Muslim communities now representing more than 50 per cent of the intake. Most of these refugees entering Australia speak little, if any, English, have little or no education in their first language, and most do not possess employment skills or qualifications valued in the Australian workplace. The Federal Government thus offers them English language training within the Adult Migrant English Programme (AMEP) and the Skills for Education and Employment (SEE) programme. These programmes aim to provide refugee migrants with enough English proficiency to gain employment in Australia, and to successfully participate socially and economically in Australian society. However, there has been only limited research specifically centred on these Federal English training programmes. In particular, there have been no in-depth studies centred on the opinions of the actual refugee clients attending these programmes. The research in this thesis thus investigates the perspectives of a group of eight male Muslim refugees on the effectiveness of the Federal English Language Training Programmes in facilitating their settlement and employment in Australia. Male Muslim refugees were chosen as participants as they represent a particularly disadvantaged, but under-researched, minority social group in Australian society. A qualitative research design and methodology was adopted for this research, framed within a socio-critical (transformative) research paradigm. Data was collected using in-depth, semi- structured interviews, and then analysed and described using the theoretical framework of Pierre Bourdieu’s conceptual tools of field, capital and habitus. The findings from this research suggest that there may be a number of key problems with the language training programmes. Most of the refugees in the study failed to find consistent employment, and many entered a repetitive cycle of intermittent attendance at the English training programmes. Additionally, many of the participants reached only a basic proficiency in oral English communication, making little or no progress in their literacy acquisition, and thus they were generally unable to complete any vocational qualifications.