Blast response and safety evaluation of a composite column for use as key element in structural systems

This paper presents the blast response, damage mechanism and evaluation of residual load capacity of a concrete–steel composite (CSC) column using dynamic computer simulation techniques. This study is an integral part of a comprehensive research program which investigated the vulnerability of structural framing systems to catastrophic and progressive collapse under blast loading and is intended to provide design information on blast mitigation and safety evaluation of load bearing vulnerable columns that are key elements in a building. The performance of the CSC column is compared with that of a reinforced concrete (RC) column with the same dimensions and steel ratio. Results demonstrate the superior performance of the CSC column, compared to the RC column in terms of residual load carrying capacity, and its potential for use as a key element in structural systems. The procedure and results presented herein can be used in the design and safety evaluation of key elements of multi-storey buildings for mitigating the impact of blast loads.

Active awareness : supporting the intentional disclosure of awareness information in collaborative systems

This thesis opens up the design space for awareness research in CSCW and HCI. By challenging the prevalent understanding of roles in awareness processes and exploring different mechanisms for actively engaging users in the awareness process, this thesis provides a better understanding of the complexity of these processes and suggests practical solutions for designing and implementing systems that support active awareness. Mutual awareness, a prominent research topic in the fields of Computer-Supported Cooperative Work (CSCW) and Human-Computer Interaction (HCI) refers to a fundamental aspect of a person’s work: their ability to gain a better understanding of a situation by perceiving and interpreting their co-workers actions. Technologically-mediated awareness, used to support co-workers across distributed settings, distinguishes between the roles of the actor, whose actions are often limited to being the target of an automated data gathering processes, and the receiver, who wants to be made aware of the actors’ actions. This receiver-centric view of awareness, focusing on helping receivers to deal with complex sets of awareness information, stands in stark contrast to our understanding of awareness as social process involving complex interactions between both actors and receivers. It fails to take into account an actors’ intimate understanding of their own activities and the contribution that this subjective understanding could make in providing richer awareness information. In this thesis I challenge the prevalent receiver-centric notion of awareness, and explore the conceptual foundations, design, implementation and evaluation of an alternative active awareness approach by making the following five contributions. Firstly, I identify the limitations of existing awareness research and solicit further evidence to support the notion of active awareness. I analyse ethnographic workplace studies that demonstrate how actors engage in an intricate interplay involving the monitoring of their co-workers progress and displaying aspects of their activities that may be of relevance to others. The examination of a large body of awareness research reveals that while disclosing information is a common practice in face-to-face collaborative settings it has been neglected in implementations of technically mediated awareness. Based on these considerations, I introduce the notion of intentional disclosure to describe the action of users actively and deliberately contributing awareness information. I consider challenges and potential solutions for the design of active awareness. I compare a range of systems, each allowing users to share information about their activities at various levels of detail. I discuss one of the main challenges to active awareness: that disclosing information about activities requires some degree of effort. I discuss various representations of effort in collaborative work. These considerations reveal that there is a trade-off between the richness of awareness information and the effort required to provide this information. I propose a framework for active awareness, aimed to help designers to understand the scope and limitations of different types of intentional disclosure. I draw on the identified richness/effort trade-off to develop two types of intentional disclosure, both of which aim to facilitate the disclosure of information while reducing the effort required to do so. For both of these approaches, direct and indirect disclosure, I delineate how they differ from related approaches and define a set of design criteria that is intended to guide their implementation. I demonstrate how the framework of active awareness can be practically applied by building two proof-of-concept prototypes that implement direct and indirect disclosure respectively. AnyBiff, implementing direct disclosure, allows users to create, share and use shared representations of activities in order to express their current actions and intentions. SphereX, implementing indirect disclosure, represents shared areas of interests or working context, and links sets of activities to these representations. Lastly, I present the results of the qualitative evaluation of the two prototypes and analyse the results with regard to the extent to which they implemented their respective disclosure mechanisms and supported active awareness. Both systems were deployed and tested in real world environments. The results for AnyBiff showed that users developed a wide range of activity representations, some unanticipated, and actively used the system to disclose information. The results further highlighted a number of design considerations relating to the relationship between awareness and communication, and the role of ambiguity. The evaluation of SphereX validated the feasibility of the indirect disclosure approach. However, the study highlighted the challenges of implementing cross-application awareness support and translating the concept to users. The study resulted in design recommendations aimed to improve the implementation of future systems.

Introduction to the special issue on next generation network architectures, protocols, theory, systems and applications

This special issue of Networking Science focuses on Next Generation Network (NGN) that enables the deployment of access independent services over converged fixed and mobile networks. NGN is a packet-based network and uses the Internet protocol (IP) to transport the various types of traffic (voice, video, data and signalling). NGN facilitates easy adoption of distributed computing applications by providing high speed connectivity in a converged networked environment. It also makes end user devices and applications highly intelligent and efficient by empowering them with programmability and remote configuration options. However, there are a number of important challenges in provisioning next generation network technologies in a converged communication environment. Some preliminary challenges include those that relate to QoS, switching and routing, management and control, and security which must be addressed on an urgent or emergency basis. The consideration of architectural issues in the design and pro- vision of secure services for NGN deserves special attention and hence is the main theme of this special issue.

Crowdsourcing interactions : using crowdsourcing for evaluating interactive information retrieval systems

In the field of information retrieval (IR), researchers and practitioners are often faced with a demand for valid approaches to evaluate the performance of retrieval systems. The Cranfield experiment paradigm has been dominant for the in-vitro evaluation of IR systems. Alternative to this paradigm, laboratory-based user studies have been widely used to evaluate interactive information retrieval (IIR) systems, and at the same time investigate users’ information searching behaviours. Major drawbacks of laboratory-based user studies for evaluating IIR systems include the high monetary and temporal costs involved in setting up and running those experiments, the lack of heterogeneity amongst the user population and the limited scale of the experiments, which usually involve a relatively restricted set of users. In this paper, we propose an alternative experimental methodology to laboratory-based user studies. Our novel experimental methodology uses a crowdsourcing platform as a means of engaging study participants. Through crowdsourcing, our experimental methodology can capture user interactions and searching behaviours at a lower cost, with more data, and within a shorter period than traditional laboratory-based user studies, and therefore can be used to assess the performances of IIR systems. In this article, we show the characteristic differences of our approach with respect to traditional IIR experimental and evaluation procedures. We also perform a use case study comparing crowdsourcing-based evaluation with laboratory-based evaluation of IIR systems, which can serve as a tutorial for setting up crowdsourcing-based IIR evaluations.

Exploring a biomimicry based approach and key barriers to evolving water infrastructure systems

Access to clean water is essential for human life and a critical issue facing much of modern society, especially as a result of the 21st Century triad of challenges – population growth, resource scarcity and pollution – which contribute to the rising complexity of providing adequate access to this essential resource for large parts of society. As such, there is now an increasing need for innovative solutions to source, treat and distribute water to cities across the globe. This position paper explores biomimicry – emulating natural form, function, process and systems – as an alternative and sustainable design approach to traditional water infrastructure systems. The key barriers to innovations such as biomimicry are summarised, indicating that regulatory and economic grounds are some of the major hindrances to integrating alternative design approaches in the water sector in developed countries. This paper examines some of the benefits of moving past these barriers to develop sustainable, efficient and resilient solutions that provide adequate access to water in the face of contemporary challenges.

Anionic migration reactions in aromatic systems effected by collisional activation : Deprotonated anilides containing methoxycarbonyl substituents

Long-range cross-ring reactions are of minor importance in the collision-induced mass spectra (MS/MS) of [M - H]- ions of CH2OCO-C6H4-NHCOR systems: e.g. the loss of 'CD3CO2CH3' from CH3OCO-C6H4-(N) over bar COCD3. Major processes involve (i) losses of radicals to form stable radical anions, e.g. loss of a ring hydrogen atom and losses from the ester (CH3 ., CH3O . and . CO2CH3), (ii) losses of neutral molecules from the amide moiety [e.g. CO (R = H) and CH2CO (R = CH3), and proximity effects when the two substituents are ortho [e.g. loss of (CH3OD+CO2) from o-CH3OCO-C6H4 (N) over bar COCD3].

A method for risk analysis across governance systems : a great barrier reef case study

Healthy governance systems are key to delivering sound environmental management outcomes from global to local scales. There are, however, surprisingly few risk assessment methods that can pinpoint those domains and sub-domains within governance systems that are most likely to influence good environmental outcomes at any particular scale, or those if absent or dysfunctional, most likely to prevent effective environmental management. This paper proposes a new risk assessment method for analysing governance systems. This method is then tested through its preliminary application to a significant real-world context: governance as it relates to the health of Australia's Great Barrier Reef (GBR). The GBR exists at a supra-regional scale along most of the north eastern coast of Australia. Brodie et al (2012 Mar. Pollut. Bull. 65 81-100) have recently reviewed the state and trend of the health of the GBR, finding that overall trends remain of significant concern. At the same time, official international concern over the governance of the reef has recently been signalled globally by the International Union for the Conservation of Nature (IUCN). These environmental and political contexts make the GBR an ideal candidate for use in testing and reviewing the application of improved tools for governance risk assessment. © 2013 IOP Publishing Ltd.

Viewpoint : social and economic dimensions of involving savanna communities in carbon management systems

In this paper we discuss the social, economic and institutional aspects of the development of carbon management systems within Australia's tropical savannas. Land-use values in savanna landscapes are changing as a result of changing economic markets, greater recognition of native title, and growing social demands and expectations for tourism, recreation and conservation. In addition, there is increasing interest in developing markets and policy arrangements for greenhouse gas abatement, carbon sequestration and carbon trade in savannas. We argue that for carbon management to lead to national greenhouse outcomes, attention must be paid to social, economic and institutional issues in environmental planning and policy arrangements. From an economic perspective, the financial impact of carbon management on savanna enterprises will depend on appropriate and available policy mechanisms, unit price for carbon, landscape condition, existing management strategies and abatement measurements used. Local social and cultural features of communities and regions may enhance or constrain the implementation of carbon abatement strategies, depending on how they are perceived. In terms of institutional arrangements, policies and plans must support and enable carbon management. We identify three areas that require priority investigation and adjustment: regional planning arrangements, property rights, and rules for accounting at enterprise and regional scales. We conclude that the best potential for managing for carbon will be achieved while managing for range of other natural resource management outcomes, especially where managing for carbon delivers collateral benefits to enterprises.

A detailed investigation of nominally 2-D radical-farming scramjet combustion

This paper reports on an investigation of the flow/chemistry coupling inside a nominally two-dimensional inlet-fuelled scramjet configuration. The experiments were conducted at a freestream Mach number of 7.3 and a total flow enthalpy of 4.3MJ/kg corresponding to a Mach 9.7 flight condition. The phenomenon of radical-farming has been studied in detail using two-dimensional OH* chemiluminescence imaging and emission spectroscopy. High signal levels of excited OH (OH*) were detected behind the first shock reflections inside the combustion chamber upstream of any measurable pressure rise from combustion, which occurred towards the rear of the combustor. The production of OH in the first hot pocket initiates the ignition process and then accelerates the combustion process in the next downstream hot pocket. This was confirmed by numerical simulations of premixed hydrogen/air flow through the scramjet. Chemical kinetics analyses reveal that the ignition process is governed by the interaction between various reaction groups leading to a chainbranching explosion for low mean temperature and pressure combustion flowfields.

Response to “Comment on ‘Indications of energetic consequences of decoherence at short times for scattering from open quantum systems���” [AIP Advances 1, 049101 (2011)]

The Comment by Mayers and Reiter criticizes our work on two counts. Firstly, it is claimed that the quantum decoherence effects that we report in consequence of our experimental analysis of neutron Compton scattering from H in gaseous H2 are not, as we maintain, outside the framework of conventional neutron scatteringtheory. Secondly, it is claimed that we did not really observe such effects, owing to a faulty analysis of the experimental data, which are claimed to be in agreement with conventional theory. We focus in this response on the critical issue of the reliability of our experimental results and analysis. Using the same standard Vesuvio instrument programs used by Mayers et al., we show that, if the experimental results for H in gaseous H2 are in agreement with conventional theory, then those for D in gaseous D2 obtained in the same way cannot be, and vice-versa. We expose a flaw in the calibration methodology used by Mayers et al. that leads to the present disagreement over the behaviour of H, namely the ad hoc adjustment of the measured H peak positions in TOF during the calibration of Vesuvio so that agreement is obtained with the expectation of conventional theory. We briefly address the question of the necessity to apply the theory of open quantum systems.

Indications of energetic consequences of decoherence at short times for scattering from open quantum systems

Decoherence of quantum entangled particles is observed in most systems, and is usually caused by system-environment interactions. Disentangling two subsystems A and B of a quantum systemAB is tantamount to erasure of quantum phase relations between A and B. It is widely believed that this erasure is an innocuous process, which e.g. does not affect the energies of A and B. Surprisingly, recent theoretical investigations by different groups showed that disentangling two systems, i.e. their decoherence, can cause an increase of their energies. Applying this result to the context of neutronCompton scattering from H2 molecules, we provide for the first time experimental evidence which supports this prediction. The results reveal that the neutron-proton collision leading to the cleavage of the H-H bond in the sub-femtosecond timescale is accompanied by larger energy transfer (by about 3%) than conventional theory predicts. It is proposed to interpreted the results by considering the neutron-proton collisional system as an entangled open quantum system being subject to decoherence owing to the interactions with the “environment” (i.e., two electrons plus second proton of H2).

High pressure in situ diffraction studies of metal–hydrogen systems

“Hybrid” hydrogen storage, where hydrogen is stored in both the solid material and as a high pressure gas in the void volume of the tank can improve overall system efficiency by up to 50% compared to either compressed hydrogen or solid materials alone. Thermodynamically, high equilibrium hydrogen pressures in metal–hydrogen systems correspond to low enthalpies of hydrogen absorption–desorption. This decreases the calorimetric effects of the hydride formation–decomposition processes which can assist in achieving high rates of heat exchange during hydrogen loading—removing the bottleneck in achieving low charging times and improving overall hydrogen storage efficiency of large hydrogen stores. Two systems with hydrogenation enthalpies close to −20 kJ/mol H2 were studied to investigate the hydrogenation mechanism and kinetics: CeNi5–D2 and ZrFe2−xAlx (x = 0.02; 0.04; 0.20)–D2. The structure of the intermetallics and their hydrides were studied by in situ neutron powder diffraction at pressures up to 1000 bar and complementary X-ray diffraction. The deuteration of the hexagonal CeNi5 intermetallic resulted in CeNi5D6.3 with a volume expansion of 30.1%. Deuterium absorption filled three different types of interstices, Ce2Ni2 and Ni4 tetrahedra, and Ce2Ni3 half-octahedra and was accompanied by a valence change for Ce. Significant hysteresis was observed between deuterium absorption and desorption which profoundly decreased on a second absorption cycle. For the Al-modified Laves-type C15 ZrFe2−xAlx intermetallics, deuteration showed very fast kinetics of H/D exchange and resulted in a volume increase of the FCC unit cells of 23.5% for ZrFe1.98Al0.02D2.9(1). Deuterium content, hysteresis of H/D uptake and release, unit cell expansion and stability of the hydrides systematically change with the amount of Al content. In the deuteride D atoms exclusively occupy the Zr2(Fe,Al)2 tetrahedra. Observed interatomic distances are Zr–D = 1.98–2.11; (Fe, Al)–D = 1.70–1.75A˚ . Hydrogenation slightly increases the magnetic moment of the Fe atoms in ZrFe1.98Al0.02 and ZrFe1.96Al0.04 from 1.9 �B at room temperature for the alloy to 2.2 �B for its deuteride.

A Triple Bottom Line Planning Tool for Measuring Sustainability : A Systems Approach to Sustainability Using the Australian Dairy Industry as a Case Study

Sustainability is a key driver for decisions in the management and future development of organisations and industries. However, quantifying and comparing sustainability across the triple bottom line (TBL) of economy, environment and social impact, has been problematic. There is a need for a tool which can measure the complex interactions within and between the environmental, economic and social systems which affect the sustainability of an industry in a transparent, consistent and comparable way. The authors acknowledge that there are currently numerous ways in which sustainability is measured and multiple methodologies in how these measurement tools were designed. The purpose of this book is to showcase how Bayesian network modelling can be used to identify and measure environmental, economic and social sustainability variables and to understand their impact on and interaction with each other. This book introduces the Sustainability Scorecard, and describes it through a case study on sustainability of the Australian dairy industry. This study was conducted in collaboration with the Australian dairy industry.

On the maturity of open source BPM systems

In this Article, Petia Wohed, Arthur H. M. ter Hofstede, Nick Russell, Birger Andersson, and Wil M. P. van der Aalst present the results of their examination of existing open source BPM systems. Their conclusions are illuminating for both Open Source developers as well as the user community. Read their Article for the details of their study.

On power minimisation and SNR maximisation of distributed beamforming in cooperative communication systems

A comparison of relay power minimisation subject to received signal-to-noise ratio (SNR) at the receiver and SNR maximisation subject to the total transmitted power of relays for a typical wireless network with distributed beamforming is presented. It is desirable to maximise receiver quality-of-service (QoS) and also to minimise the cost of transmission in terms of power. Hence, these two optimisation problems are very common and have been addressed separately in the literature. It is shown that SNR maximisation subject to power constraint and power minimisation subject to SNR constraint yield the same results for a typical wireless network. It proves that either one of the optimisation approaches is sufficient.