Performance analysis of PTP components for IEC 61850 process bus applications

New substation automation applications, such as sampled value process buses and synchrophasors, require sampling accuracy of 1 µs or better. The Precision Time Protocol (PTP), IEEE Std 1588, achieves this level of performance and integrates well into Ethernet based substation networks. This paper takes a systematic approach to the performance evaluation of commercially available PTP devices (grandmaster, slave, transparent and boundary clocks) from a variety of manufacturers. The ``error budget'' is set by the performance requirements of each application. The ``expenditure'' of this error budget by each component is valuable information for a system designer. The component information is used to design a synchronization system that meets the overall functional requirements. The quantitative performance data presented shows that this testing is effective and informative. Results from testing PTP performance in the presence of sampled value process bus traffic demonstrate the benefit of a ``bottom up'' component testing approach combined with ``top down'' system verification tests. A test method that uses a precision Ethernet capture card, rather than dedicated PTP test sets, to determine the Correction Field Error of transparent clocks is presented. This test is particularly relevant for highly loaded Ethernet networks with stringent timing requirements. The methods presented can be used for development purposes by manufacturers, or by system integrators for acceptance testing. A sampled value process bus was used as the test application for the systematic approach described in this paper. The test approach was applied, components were selected, and the system performance verified to meet the application's requirements. Systematic testing, as presented in this paper, is applicable to a range of industries that use, rather than develop, PTP for time transfer.

An interactive and adaptive building layer : strategies for allowing people to become advanced building-users

This paper reports outcomes of a pilot study to develop a conceptual framework to allow people to retrofit a building-layer to gain better control of their own built- environments. The study was initiated by the realisation that discussions surrounding the improvement of building performances tend to be about top-down technological solutions rather than to help and encourage bottom-up involvement of building-users. While users are the ultimate beneficiaries and their feedback is always appreciated, their direct involvements in managing buildings would often be regarded as obstruction or distraction. This is largely because casual interventions by uninformed building-users tend to disrupt the system. Some earlier researches showed however that direct and active participation of users could improve the building performance if appropriate training and/or systems were introduced. We also speculate this in long run would also make the built environment more sustainable. With this in mind, we looked for opportunities to retrofit our own office with an interactive layer to study how we could introduce ad-hoc systems for building-users. The aim of this paper is to describe our vision and initial attempts followed by discussion.

Custom digital workflows : a new framework for design analysis integration

Flexible information exchange is critical to successful design-analysis integration, but current top-down, standards-based and model-oriented strategies impose restrictions that contradicts this flexibility. In this article we present a bottom-up, user-controlled and process-oriented approach to linking design and analysis applications that is more responsive to the varied needs of designers and design teams. Drawing on research into scientific workflows, we present a framework for integration that capitalises on advances in cloud computing to connect discrete tools via flexible and distributed process networks. We then discuss how a shared mapping process that is flexible and user friendly supports non-programmers in creating these custom connections. Adopting a services-oriented system architecture, we propose a web-based platform that enables data, semantics and models to be shared on the fly. We then discuss potential challenges and opportunities for its development as a flexible, visual, collaborative, scalable and open system.

Custom digital workflows : a new framework for design analysis integration

Flexible information exchange is critical to successful design integration, but current top-down, standards-based and model-oriented strategies impose restrictions that are contradictory to this flexibility. In this paper we present a bottom-up, user-controlled and process-oriented approach to linking design and analysis applications that is more responsive to the varied needs of designers and design teams. Drawing on research into scientific workflows, we present a framework for integration that capitalises on advances in cloud computing to connect discrete tools via flexible and distributed process networks. Adopting a services-oriented system architecture, we propose a web-based platform that enables data, semantics and models to be shared on the fly. We discuss potential challenges and opportunities for the development thereof as a flexible, visual, collaborative, scalable and open system.

Catalysing design principles through the dreaming of sustainable subtropical cityscapes : the collaborative construction of new place identities

This paper addresses the question of how to open up pathways and build capacity to facilitate the movement towards sustainable sub-tropical cities. The focus is on outlining a collaborative planning and co-design process that can help catalyse the emergence of sustainable place-habitats and so re-weave and colour anew the tapestry of our sub-tropical cities. Cities are portrayed as self-organising complex adaptive system phenomena, being constantly re-shaped by local and global social-political, environmental, cultural and economic forces as well as planning regimes. While constructing a sustainable city is at essence a design process incorporating new sustainable practices and legislation to reinforce their use, these steps are necessary but not sufficient. Sustainable sub-tropical city-making could be re-thought as a dreaming-re-storying process. This paper explores a new co-design process, which can channel collaborative efforts around re-inventing sustainable place-habitats across the cityscape. A further outcome of this co-design process is the alignment of the emergent design principles and planning actions that can trigger the re-storying of a new sustainable sub-tropical city. Besides a new co-design process, we also advocate the building of sub-tropical city learning networks to facilitate the cross-fertilization for Dreaming sustainable sub-tropical cities.

A critical assessment of the Australian OHS accreditation system's "Body of Knowledge (BoK)"

In response to an increasing perception of poor OHS consultancy quality amongst the Australian public, regulator and OHS professionals, the Safety Institute Australia (SIA) was tasked by the Victorian government to establish an accreditation process for OHS professionals. The OHS accreditation board decided to base its accreditation on a core "body of knowledge" (BoK), against which applicants are assesssed. While the foundation and structure of the BoK is unclear, the BoK consists of a collection of essays from a variety of invited authors. The BoK comprises about 811 pages in 34 chapters, with significant redundancy and considerable subjective components. The SIA BoK is benchmarked against two international best-practices, the German "Core Definition, Object Catalog and Research Domains of Labour Science (Ergonomics)" (Luzcak, Volpert, Raeithel & Schwier, 1989)(100 pages) and the American "Core Competency Model" for the "Master's Degree in Public Health" (Association of Schools of Public Health, 2006) (21 pages). Both "core definition" and "core competency model" are on a comparative level to the BoK. While the German expert panel consisted of 14 eminent professors, the American panel consisted of 135 members, organized in 6 groups chaired by discipline leading academics. The Australian approach employed a broad approach, where 137 professionals, consultants, emerging academics and academics contributed to 8 workshops. Both the German and the American panels maintained an open communication amongst members and with the discipline community throughout the process, whereas SIA applied an open and directed peer-review process. Moreover, the German process involved an analysis of all congress content and journal publications in the scientific domain in a set timeframe, which were then systematically clustered. These results were further expanded by structured interviews with 38 professors in the discpline, grasping their research and teaching practice. The American workgroup however assumed core scientific areas, underlying the domain. Based upon the a-priori assumption, they then established well defined competencies across all areas using a modified Delphi process. Although the BoK attempts to explore the knowledge in the OHS domain without an imposed structure in a bottom-up approach, it does not result in a structured systematic of the science. We conclude that the outcome of the German, rigorous academic approach, and the US American democratic approach under unambiguous academic leadership both outperform the Australian advocacy group approach. This product was determined for both structure and content of the taxonomy delivered through the processes.

Participatory approach to support community development of rural craftspeople

This paper presents a case study of the participatory project in the Jombang glass bead craft industry. Economic instability has brought significant business challenges in the community. The involvement of outsiders to collaborate with craftspeople in order to support business innovation as well as strengthen the social capital in the community is essential. However, facilitating a rural community to formulate and implement bottom-up planning needs an integrated approach. In this paper, we explain a participatory project in the rural craftspeople community that resulted in a collective action. The project aimed at uniting and empowering rural craftspeople focusing on the unique skills and knowledge of participants. There are some aspects influencing the success of collective action: the ability to understand the local political situation; the role of facilitators to respect and support the unique potential of craftspeople; and the economic benefit of the program.

Characterising one-to-one conservatoire teaching : Some implications of a quantitative analysis

Despite the significant recent growth in research relating to instrumental, vocal and composition tuition in higher education, little is known about the diversity of approaches that characterise one-to-one teaching in the Conservatoire, and what counts as optimal practice for educating 21st-century musicians. Through analysis of video-recorded one-to-one lessons that draws on a ‘bottom up’ methodology for characterising pedagogical practices (Taylor, 2012; Taylor et al, 2012), this paper provides empirical evidence about the nature of one-to-one pedagogy in one Australian institution. The research aims (1) to enable a better understanding of current one-to-one conservatoire teaching; and (2) to build and improve upon existing teaching practice using authentic insights gained through systematic investigation. The authors hope the research will lead to a better understanding of the diversity and efficacy of the pedagogical practice within the specific context in which the study was conducted, and beyond, to Conservatoire pedagogy generally.

Life-history constraints in grassland plant species : a growth-defence trade-off is the norm

Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade-off possibilities. The competition-defence hypothesis posits a trade-off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth-defence hypothesis suggests that strong competitors for nutrients are also defended against enemies, at a cost to growth rate. We tested these hypotheses using observations of 706 plant populations of over 500 species before and following identical fertilisation and fencing treatments at 39 grassland sites worldwide. Strong positive covariance in species responses to both treatments provided support for a growth-defence trade-off: populations that increased with the removal of nutrient limitation (poor competitors) also increased following removal of consumers. This result held globally across 4 years within plant life-history groups and within the majority of individual sites. Thus, a growth-defence trade-off appears to be the norm, and mechanisms maintaining grassland biodiversity may operate within this constraint.

Agent-based model of passenger flows in airport terminals

Passenger flow studies in airport terminals have shown consistent statistical relationships between airport spatial layout and pedestrian movement, facilitating prediction of movement from terminal designs. However, these studies are done at an aggregate level and do not incorporate how individual passengers make decisions at a microscopic level. Therefore, they do not explain the formation of complex movement flows. In addition, existing models mostly focus on standard airport processing procedures such as immigration and security, but seldom consider discretionary activities of passengers, and thus are not able to truly describe the full range of passenger flows within airport terminals. As the route-choice decision-making of passengers involves many uncertain factors within the airport terminals, the mechanisms to fulfill the capacity of managing the route-choice have proven difficult to acquire and quantify. Could the study of cognitive factors of passengers (i.e. human mental preferences of deciding which on-airport facility to use) be useful to tackle these issues? Assuming the movement in virtual simulated environments can be analogous to movement in real environments, passenger behaviour dynamics can be similar to those generated in virtual experiments. Three levels of dynamics have been devised for motion control: the localised field, tactical level, and strategic level. A localised field refers to basic motion capabilities, such as walking speed, direction and avoidance of obstacles. The other two fields represent cognitive route-choice decision-making. This research views passenger flow problems via a "bottom-up approach", regarding individual passengers as independent intelligent agents who can behave autonomously and are able to interact with others and the ambient environment. In this regard, passenger flow formation becomes an emergent phenomenon of large numbers of passengers interacting with others. In the thesis, first, the passenger flow in airport terminals was investigated. Discretionary activities of passengers were integrated with standard processing procedures in the research. The localised field for passenger motion dynamics was constructed by a devised force-based model. Next, advanced traits of passengers (such as their desire to shop, their comfort with technology and their willingness to ask for assistance) were formulated to facilitate tactical route-choice decision-making. The traits consist of quantified measures of mental preferences of passengers when they travel through airport terminals. Each category of the traits indicates a decision which passengers may take. They were inferred through a Bayesian network model by analysing the probabilities based on currently available data. Route-choice decision-making was finalised by calculating corresponding utility results based on those probabilities observed. Three sorts of simulation outcomes were generated: namely, queuing length before checkpoints, average dwell time of passengers at service facilities, and instantaneous space utilisation. Queuing length reflects the number of passengers who are in a queue. Long queues no doubt cause significant delay in processing procedures. The dwell time of each passenger agent at the service facilities were recorded. The overall dwell time of passenger agents at typical facility areas were analysed so as to demonstrate portions of utilisation in the temporal aspect. For the spatial aspect, the number of passenger agents who were dwelling within specific terminal areas can be used to estimate service rates. All outcomes demonstrated specific results by typical simulated passenger flows. They directly reflect terminal capacity. The simulation results strongly suggest that integrating discretionary activities of passengers makes the passenger flows more intuitive, observing probabilities of mental preferences by inferring advanced traits make up an approach capable of carrying out tactical route-choice decision-making. On the whole, the research studied passenger flows in airport terminals by an agent-based model, which investigated individual characteristics of passengers and their impact on psychological route-choice decisions of passengers. Finally, intuitive passenger flows in airport terminals were able to be realised in simulation.

A dynamic approach for evaluating earthwork hauls in construction

A graph theoretic approach is developed for accurately computing haulage costs in earthwork projects. This is vital as haulage is a predominant factor in the real cost of earthworks. A variety of metrics can be used in our approach, but a fuel consumption proxy is recommended. This approach is novel as it considers the constantly changing terrain that results from cutting and filling activities and replaces inaccurate “static” calculations that have been used previously. The approach is also capable of efficiently correcting the violation of top down cutting and bottom up filling conditions that can be found in existing earthwork assignments and sequences. This approach assumes that the project site is partitioned into uniform blocks. A directed graph is then utilised to describe the terrain surface. This digraph is altered after each cut and fill, in order to reflect the true state of the terrain. A shortest path algorithm is successively applied to calculate the cost of each haul and these costs are summed to provide a total cost of haulage

Vote with your feet : hyperlocal polling for urban screens

Vote with Your Feet is a hyperlocal polling tool for urban screens that lets users express their opinion on current affairs. Similar to vox populi interviews on TV, it is meant to reflect the mindset of the community and its diversity. It shows one Yes/No question at a time and lets the user vote by stepping with their foot on one of two physical buttons. By not only displaying the local but also national results (taken from newspaper polls or TV news), it creates a sense of place and can spark offline conversations as well as making people think about their own opinion. As a tangible media installation that bridges physical and digital urban layers, the project empowers citizens and facilitates a bottom-up approach in terms of stimulating opinions and decision making (rather than broadcasting or automating). In a second iteration of the design, we want to encourage users to submit their own questions.

Enterprise social networks : a business model perspective

Enterprise Social Networks continue to be adopted by organisations looking to increase collaboration between employees, customers and industry partners. Offering a varied range of features and functionality, this technology can be distinguished by the underlying business models that providers of this software deploy. This study identifies and describes the different business models through an analysis of leading Enterprise Social Networks: Yammer, Chatter, SharePoint, Connections, Jive, Facebook and Twitter. A key contribution of this research is the identification of consumer and corporate models as extreme approaches. These findings align well with research on the adoption of Enterprise Social Networks that has discussed bottom-up and top-down approaches. Of specific interest are hybrid models that wrap a corporate model within a consumer model and may, therefore, provide synergies on both models. From a broader perspective, this can be seen as the merging of the corporate and consumer markets for IT products and services.

Regulating online : participant-driven approaches

This thesis considers and evaluates different approaches to regulating online gaming communities, including traditional top-down regulation, as well as bottom-up and hybrid forms led by participants. I examine the regulatory environment in both the video game and gambling industries through case studies of the science fiction, massively multiplayer game Eve Online and offshore gambling platforms and their community sites. I identify that the participant driven approach to regulation sometimes used in the offshore gambling industry was dependent on a number of factors, notably the strength of the community and the risks to platform operators of negative publicity. By subsequently comparing this to the video gaming industry, I suggest that participant driven processes may be an appropriate way to resolve disputes in the games industry, and show how these are – to a limited extent – already being applied.

Don't think but look : a Gestalt interactionist approach to legal thinking

We propose here a new approach to legal thinking that is based on principles of Gestalt perception. Using a Gestalt view of perception, which sees perception as the process of building a conceptual representation of the given stimulus, we articulate legal thinking as the process of building a representation for the given facts of a case. We propose a model in which top-down and bottom-up processes interact together to build arguments (or representations) in legal thinking. We discuss some implications of our approach, especially with respect to modeling precedential reasoning and creativity in legal thinking.