Protection of distributed generation interfaced networks

With the rapid increase in electrical energy demand, power generation in the form of distributed generation is becoming more important. However, the connections of distributed generators (DGs) to a distribution network or a microgrid can create several protection issues. The protection of these networks using protective devices based only on current is a challenging task due to the change in fault current levels and fault current direction. The isolation of a faulted segment from such networks will be difficult if converter interfaced DGs are connected as these DGs limit their output currents during the fault. Furthermore, if DG sources are intermittent, the current sensing protective relays are difficult to set since fault current changes with time depending on the availability of DG sources. The system restoration after a fault occurs is also a challenging protection issue in a converter interfaced DG connected distribution network or a microgrid. Usually, all the DGs will be disconnected immediately after a fault in the network. The safety of personnel and equipment of the distribution network, reclosing with DGs and arc extinction are the major reasons for these DG disconnections. In this thesis, an inverse time admittance (ITA) relay is proposed to protect a distribution network or a microgrid which has several converter interfaced DG connections. The ITA relay is capable of detecting faults and isolating a faulted segment from the network, allowing unfaulted segments to operate either in grid connected or islanded mode operations. The relay does not make the tripping decision based on only the fault current. It also uses the voltage at the relay location. Therefore, the ITA relay can be used effectively in a DG connected network in which fault current level is low or fault current level changes with time. Different case studies are considered to evaluate the performance of the ITA relays in comparison to some of the existing protection schemes. The relay performance is evaluated in different types of distribution networks: radial, the IEEE 34 node test feeder and a mesh network. The results are validated through PSCAD simulations and MATLAB calculations. Several experimental tests are carried out to validate the numerical results in a laboratory test feeder by implementing the ITA relay in LabVIEW. Furthermore, a novel control strategy based on fold back current control is proposed for a converter interfaced DG to overcome the problems associated with the system restoration. The control strategy enables the self extinction of arc if the fault is a temporary arc fault. This also helps in self system restoration if DG capacity is sufficient to supply the load. The coordination with reclosers without disconnecting the DGs from the network is discussed. This results in increased reliability in the network by reduction of customer outages.

Volcanology and petrology of submarine volcanoes of the New Hebrides island arc

The New Hebrides Island Arc, an intra-oceanic island chain in the southwest Pacific, is formed by subduction of the Indo-Australian Plate beneath the Pacific Plate. The southern end of the New Hebrides Island Arc is an ideal location to study the magmatic and tectonic interaction of an emerging island arc as this part of the island chain is less than 3 million years old. A tectonically complex island arc, it exhibits a change in relative subduction rate from ~12cm/yr to 6 cm/yr before transitioning to a left-lateral strike slip zone at its southern end. Two submarine volcanic fields, Gemini-Oscostar and Volsmar, occur at this transition from normal arc subduction to sinistral strike slip movement. Multi-beam bathymetry and dredge samples collected during the 2004 CoTroVE cruise onboard the RV Southern Surveyor help define the relationship between magmatism and tectonics, and the source for these two submarine volcanic fields. Gemini-Oscostar volcanic field (GOVF), dominated by northwest-oriented normal faults, has mature polygenetic stratovolcanoes with evidence for explosive subaqueous eruptions and homogeneous monogenetic scoria cones. Volsmar volcanic field (VVF), located 30 km south of GOVF, exhibits a conjugate set of northwest and eastwest-oriented normal faults, with two polygenetic stratovolcanoes and numerous monogenetic scoria cones. A deep water caldera provides evidence for explosive eruptions at 1500m below sea level in the VVF. Both volcanic fields are dominated by low-K island arc tholeiites and basaltic andesites with calcalkalic andesite and dacite being found only in the GOVF. Geochemical signatures of both volcanic fields continue the along-arc trend of decreasing K2O with both volcanic fields being similar to the New Hebrides central chain lavas. Lavas from both fields display a slight depletion in high field strength elements and heavy rare earth elements, and slight enrichments in large-ion lithophile elements and light rare earth elements with respect to N-MORB mantle. Sr and Nd isotope data correlate with heavy rare earth and high field strength element data to show that both fields are derived from depleted mantle. Pb isotopes define Pacific MORB mantle sources and are consistent with isotopic variation along the New Hebrides Island Arc. Pb isotopes show no evidence for sediment contamination; the subduction component enrichment is therefore a slab-derived enrichment. There is a subtle spatial variation in source chemistry which sees a northerly trend of decreasing enrichment of slab-derived fluids.

Beam steering with high front-to-back ratio and high directivity on small platforms using decoupled antenna pairs

Beam steering with high front-to-back ratio and high directivity on a small platform is proposed. Two closely spaced antenna pairs with eigenmode port decoupling are used as the basic radiating elements. Two orthogonal radiation patterns are obtained for each antenna pair. High front-to-back ratio and high directivity are achieved by combining the two orthogonal radiation patterns. With an infinite groundplane, a front-to-back ratio of 21 dB with a directivity of 9.8 dB can be achieved. Beam steering, at the expense of a slight decrease in directivity, is achieved by placing the two antenna pairs 0.5λ apart. The simulated half power beamwidth is 58°. A prototype was designed and the 2-D radiation patterns were measured. The prototype supports three directions of beam steering. The half power beamwidth was measured as 46°, 48°, and 50° for the three respective beam directions. The measured front-to-back ratio in azimuth plane is 8.5 dB, 8.0 dB and 7.6 dB, respectively.

Culture and creative industries in Australia

It has been argued that the origins of modern creative industries policies can be found in Australia. The Creative Nation national cultural policy statement released by the Labor government headed by the Prime Minister Paul Keating in 1994 sought an original synthesis of arts and media policies that was outwardly looking, identifying the opportunities presented by what were then new digital media technologies, and clearly stated the economic opportunities presented by promotion of what were referred to at the time as the cultural industries. Several commentators have identified the influence that Creative Nation had on the Blair Labour government when it came to power in the United Kingdom in 1997. Faced with the question of how to revitalise the once-mighty industrial cities of the U.K. after the Conservative government, the Department of Culture, Media and Sport drew upon policy documents such as Australia’s Creative Nation, as well as the experience of local governments in these cities, in looking to the cultural sectors to spearhead new jobs growth, as well as re-branding the cities as cultural or creative cities in a post-industrial economic landscape. This growing alignment of culture and economics, that has been a characteristic of creative industries policies as they have developed in Australia, Britain, East Asia and Europe, marks an interesting shift in the traditional focus of arts and cultural policy as compensatory to the economic domain. The first Chair of what would become the Arts Council of Great Britain (now the Arts Council of England) was the famous economist John Maynard Keynes. In the First Annual Report of the Arts Council for 1945-1946, prepared in the latter stages of the Second World War, Keynes proposed that “the day is not far off when the economic problem will take the back seat where it belongs, and the arena of the heart and the head will be occupied or reoccupied, by our real problems — the problems of life and of human relations, of creation and behaviour and religion”. 中文摘要 1994年工黨執政時期澳洲總理基挺（Paul Keating）發表創意的國家（The Creative Nation）的文化政策聲明堪稱是澳洲現代創意產業的起源，該聲明試圖將藝術與媒體政策結合在一起，其目的在面向海外，為新數位媒體技術尋找機會。聲明中明確指出要推動文化產業為經濟帶來機會。「文化政策也是經濟政策。文化創造財富與附加價值，對創新、行銷與設計有重要貢獻，是我們工業的標誌（badge）。我們創意的層次實際上決定了我們適應新經濟imperatives的能力。文化本身就是項重要出口，是其他產品出口的主要附件（essential accompaniment）。文化吸引觀光與學生，也是我們經濟成功之關鍵。」 創意產業的策略是構建藝術、媒體與資訊電信科技的網絡以利文化產業在國家創新政策策略中擁有一席之地。此一策略最早是由1990年代末英國布萊爾（Tony Blair）的新工黨政府所採行，其後歐洲聯盟、澳洲、紐西蘭、新加坡、台灣、南韓與中國。

Bouncing back : the role of design in facilitating students to understand and deal with adversity

After state-wide flooding and a category-5 tropical cyclone, three-quarters of the state of Queensland was declared a disaster zone in early 2011. This deluge of adversity had a significant impact on university students, a few weeks prior to the start of the academic semester. The purpose of this paper is to examine the role that design plays in facilitating students to understand and respond to, adversity. The participants of this study were second and fourth year architectural design students at a large Australian University, in Queensland. As a part of their core architectural design studies, students were required to provide architectural responses to the recent catastrophic events in Queensland. Qualitative data was obtained through student surveys, work design work submitted by students and a survey of guests who attending an exhibition of the student work. The results of this research showed that the students produced more than just the required set of architectural drawings, process journals and models, but also recognition of the important role that the affective dimension of the flooding event and the design process played in helping them to both understand and respond to, adversity. They held the ‘real world’ experience and practical aspect of the assessment in higher regard than their typical focus on aesthetics and the making of iconic design. Perhaps most importantly, the students recognised that this process allowed them to have a voice, and a means to respond to adversity through the powerful language of design.

Bouncing back : Resilient design for Brisbane - Exhibition

"Bouncing Back: Resilient Design for Brisbane" was an opportunity for QUT students to communicate their inspiring design responses to adversity, to the larger Brisbane community. The exhibition demonstrates new and innovative ways of thinking about our cities, and how they are built to be resilient and to suit extreme environmental conditions. The challenge for architecture students is to address the state of architecture as a reflection of today's world and to consider how design fits into the 21st century. Students have explored notions of 'Urban Resilience' from multiple perspectives, including emergency design while facing flooding, flood proof housing and urban designs.

Sky high and back again : the evolution of simulation-based design from aerospace to construction

Emerging from the challenge to reduce energy consumption in buildings is a need for research and development into the more effective use of simulation as a decision-support tool. Despite significant research, persistent limitations in process and software inhibit the integration of energy simulation in early architectural design. This paper presents a green star case study to highlight the obstacles commonly encountered with current integration strategies. It then examines simulation-based design in the aerospace industry, which has overcome similar limitations. Finally, it proposes a design system based on this contrasting approach, coupling parametric modelling and energy simulation software for rapid and iterative performance assessment of early design options.

Arc voltage behavior in GMAW-P under different drop transfer modes

Purpose: Experimental measurements have been made to investigate meaning of the change in voltage for the pulse gas metal arc welding (GMAW-P) process operating under different drop transfer modes. Design/methodology/approach: Welding experiments with different values of pulsing parameter and simultaneous recording of high speed camera pictures and welding signals (such as current and voltage) were used to identify different drop transfer modes in GMAW-P. The investigation is based on the synchronization of welding signals and high speed camera to study the behaviour of voltage signal under different drop transfer modes. Findings: The results reveal that the welding arc is significantly affected by the molten droplet detachment. In fact, results indicate that sudden increase and drop in voltage just before and after the drop detachment can be used to characterize the voltage behaviour of different drop transfer mode in GMAW-P. Research limitations/implications: The results show that voltage signal carry rich information about different drop transfer occurring in GMAW-P. Hence it’s possible to detect different drop transfer modes. Future work should concentrate on development of filters for detection of different drop transfer modes. Originality/value: Determination of drop transfer mode with GMAW-P is crucial for the appropriate selection of pulse welding parameters. As change in drop transfer mode results in poor weld quality in GMAW-P, so in order to estimate the working parameters and ensure stable GMAW-P understanding the voltage behaviour of different drop transfer modes in GMAW-P will be useful. However, in case of GMAW-P hardly any attempt is made to analyse the behaviour of voltage signal for different drop transfer modes. This paper analyses the voltage signal behaviour of different drop transfer modes for GMAW-P.

Murray-Darling basin governance : the focus of the law

The legal arrangements for the management of the Murray-Darling Basin in Australia have changed significantly over the years. The Constitution of the Commonwealth has led to the legal arrangements for the management of the Murray-Darling Basin. The Water Act 2000 of Queensland aimed at advancing sustainable management and efficient use of water and other resources by establishing a system for the planning, allocation and use of water. The Water Management Act 2000 of New South Wales ensures the sustainable and integrated management of the water resources of the state benefiting the present and future generations. The Natural Resources Management Act 2004 of South Australia applies to water resources and to other natural resources. The Act aimed at assisting the achievement of ecologically sustainable development in the state.

Effectiveness of powered hospital bed movers for reducing physiological strain and back muscle activation

Battery powered bed movers are becoming increasingly common within the hospital setting. The use of powered bed movers is believed to result in reduced physical efforts required by health care workers, which may be associated with a decreased risk of occupation related injuries. However, little work has been conducted assessing how powered bed movers impact on levels of physiological strain and muscle activation for the user. The muscular efforts associated with moving hospital beds using three different methods; manual pushing, StaminaLift Bed Mover (SBM) and Gzunda Bed Mover (GBM)were measured on six male subjects. Fourteen muscles were assessed moving a weighted hospital bed along a standardized route in an Australian hospital environment. Trunk inclination and upper spine acceleration were also quantified. Powered bed movers exhibited significantly lower muscle activation levels than manual pushing for the majority of muscles. When using the SBM, users adopted a more upright posture which was maintained while performing different tasks (e.g. turning a corner, entering a lift), while trunk inclination varied considerably for manual pushing and the GBM. The reduction in lower back muscular activation levels and the load reducing effect of a more upright posture may result in lower incidence of lower back injury.

A software framework for risk-aware business process management

With the large diffusion of Business Process Managemen (BPM) automation suites, the possibility of managing process-related risks arises. This paper introduces an innovative framework for process-related risk management and describes a working implementation realized by extending the YAWL system. The framework covers three aspects of risk management: risk monitoring, risk prevention, and risk mitigation. Risk monitoring functionality is provided using a sensor-based architecture, where sensors are defined at design time and used at run-time for monitoring purposes. Risk prevention functionality is provided in the form of suggestions about what should be executed, by who, and how, through the use of decision trees. Finally, risk mitigation functionality is provided as a sequence of remedial actions (e.g. reallocating, skipping, rolling back of a work item) that should be executed to restore the process to a normal situation.