Generic one round group key exchange in the standard model

Minimizing complexity of group key exchange (GKE) protocols is an important milestone towards their practical deployment. An interesting approach to achieve this goal is to simplify the design of GKE protocols by using generic building blocks. In this paper we investigate the possibility of founding GKE protocols based on a primitive called multi key encapsulation mechanism (mKEM) and describe advantages and limitations of this approach. In particular, we show how to design a one-round GKE protocol which satisfies the classical requirement of authenticated key exchange (AKE) security, yet without forward secrecy. As a result, we obtain the first one-round GKE protocol secure in the standard model. We also conduct our analysis using recent formal models that take into account both outsider and insider attacks as well as the notion of key compromise impersonation resilience (KCIR). In contrast to previous models we show how to model both outsider and insider KCIR within the definition of mutual authentication. Our analysis additionally implies that the insider security compiler by Katz and Shin from ACM CCS 2005 can be used to achieve more than what is shown in the original work, namely both outsider and insider KCIR.

Exploiting medical hierarchies for concept-based information retrieval

Search technologies are critical to enable clinical sta to rapidly and e ectively access patient information contained in free-text medical records. Medical search is challenging as terms in the query are often general but those in rel- evant documents are very speci c, leading to granularity mismatch. In this paper we propose to tackle granularity mismatch by exploiting subsumption relationships de ned in formal medical domain knowledge resources. In symbolic reasoning, a subsumption (or `is-a') relationship is a parent-child rela- tionship where one concept is a subset of another concept. Subsumed concepts are included in the retrieval function. In addition, we investigate a number of initial methods for combining weights of query concepts and those of subsumed concepts. Subsumption relationships were found to provide strong indication of relevant information; their inclusion in retrieval functions yields performance improvements. This result motivates the development of formal models of rela- tionships between medical concepts for retrieval purposes.

The Quantum Probability Ranking Principle for Information Retrieval

While the Probability Ranking Principle for Information Retrieval provides the basis for formal models, it makes a very strong assumption regarding the dependence between documents. However, it has been observed that in real situations this assumption does not always hold. In this paper we propose a reformulation of the Probability Ranking Principle based on quantum theory. Quantum probability theory naturally includes interference effects between events. We posit that this interference captures the dependency between the judgement of document relevance. The outcome is a more sophisticated principle, the Quantum Probability Ranking Principle, that provides a more sensitive ranking which caters for interference/dependence between documents’ relevance.

Workflow patterns as a means to model task succession in games – a preliminary case study

Over about the last decade, people involved in game development have noted the need for more formal models and tools to support the design phase of games. It is argued that the present lack of such formal tools is currently hindering knowledge transfer among designers. Formal visual languages, on the other hand, can help to more effectively express, abstract and communicate game design concepts. Moreover, formal tools can assist in the prototyping phase, allowing designers to reason about and simulate game mechanics on an abstract level. In this paper we present an initial investigation into whether workflow patterns – which have already proven to be effective for modeling business processes – are a suitable way to model task succession in games. Our preliminary results suggest that workflow patterns show promise in this regard but some limitations, especially in regard to time constraints, currently restrict their potential.

Legal mechanisms for maximising community engagement with formal evacuation messaging: How well are these understood?

Study/Objective This program of research examines the effectiveness of legal mechanisms as motivators to maximise engagement and compliance with evacuation messages. This study is based on the understanding that the presence of legislative requirements, as well as sanctions and incentives encapsulated in law, can have a positive impact in achieving compliance. Our objective is to examine whether the current Australian legal frameworks, which incorporate evacuation during disasters, are an effective structure that is properly understood by those who enforce and those who are required to comply. Background In Australia, most jurisdictions have enacted legislation that encapsulates the power to evacuate and the ability to enforce compliance, either by the use of force or imposition of penalty. However, citizens still choose to not evacuate. Methods This program of research incorporates theoretical and doctrinal methodologies for reviewing literature and legislation in the Australia context. The aim of the research is to determine whether further clarity is required to create an understanding of the powers to evacuate, as well as greater public awareness of these powers. Results & Conclusion Legislators suggest that powers of evacuation can be ineffective if they are impractical to enforce. In Australia, there may also be confusion about from which legislative instrument the power to evacuate derives, and therefore whether there is a corresponding ability to enforce compliance through the use of force or imposition of a penalty. Equally, communities may lack awareness and understanding of the powers of agencies to enforce compliance. We seek to investigate whether this is the case, and whether even if greater awareness existed, it would act as an incentive to comply.

Bayesian hybrid algorithms and models : implementation and associated issues

This thesis addresses computational challenges arising from Bayesian analysis of complex real-world problems. Many of the models and algorithms designed for such analysis are ‘hybrid’ in nature, in that they are a composition of components for which their individual properties may be easily described but the performance of the model or algorithm as a whole is less well understood. The aim of this research project is to after a better understanding of the performance of hybrid models and algorithms. The goal of this thesis is to analyse the computational aspects of hybrid models and hybrid algorithms in the Bayesian context. The first objective of the research focuses on computational aspects of hybrid models, notably a continuous finite mixture of t-distributions. In the mixture model, an inference of interest is the number of components, as this may relate to both the quality of model fit to data and the computational workload. The analysis of t-mixtures using Markov chain Monte Carlo (MCMC) is described and the model is compared to the Normal case based on the goodness of fit. Through simulation studies, it is demonstrated that the t-mixture model can be more flexible and more parsimonious in terms of number of components, particularly for skewed and heavytailed data. The study also reveals important computational issues associated with the use of t-mixtures, which have not been adequately considered in the literature. The second objective of the research focuses on computational aspects of hybrid algorithms for Bayesian analysis. Two approaches will be considered: a formal comparison of the performance of a range of hybrid algorithms and a theoretical investigation of the performance of one of these algorithms in high dimensions. For the first approach, the delayed rejection algorithm, the pinball sampler, the Metropolis adjusted Langevin algorithm, and the hybrid version of the population Monte Carlo (PMC) algorithm are selected as a set of examples of hybrid algorithms. Statistical literature shows how statistical efficiency is often the only criteria for an efficient algorithm. In this thesis the algorithms are also considered and compared from a more practical perspective. This extends to the study of how individual algorithms contribute to the overall efficiency of hybrid algorithms, and highlights weaknesses that may be introduced by the combination process of these components in a single algorithm. The second approach to considering computational aspects of hybrid algorithms involves an investigation of the performance of the PMC in high dimensions. It is well known that as a model becomes more complex, computation may become increasingly difficult in real time. In particular the importance sampling based algorithms, including the PMC, are known to be unstable in high dimensions. This thesis examines the PMC algorithm in a simplified setting, a single step of the general sampling, and explores a fundamental problem that occurs in applying importance sampling to a high-dimensional problem. The precision of the computed estimate from the simplified setting is measured by the asymptotic variance of the estimate under conditions on the importance function. Additionally, the exponential growth of the asymptotic variance with the dimension is demonstrated and we illustrates that the optimal covariance matrix for the importance function can be estimated in a special case.

Fundamentals of process integration

Technologies and languages for integrated processes are a relatively recent innovation. Over that period many divergent waves of innovation have transformed process integration. Like sockets and distributed objects, early workflow systems ordered programming interfaces that connected the process modelling layer to any middleware. BPM systems emerged later, connecting the modelling world to middleware through components. While BPM systems increased ease of use (modelling convenience), long-standing and complex interactions involving many process instances remained di±cult to model. Enterprise Service Buses (ESBs), followed, connecting process models to heterogeneous forms of middleware. ESBs, however, generally forced modellers to choose a particular underlying middleware and to stick to it, despite their ability to connect with many forms of middleware. Furthermore ESBs encourage process integrations to be modelled on their own, logically separate from the process model. This can lead to the inability to reason about long standing conversations at the process layer. Technologies and languages for process integration generally lack formality. This has led to arbitrariness in the underlying language building blocks. Conceptual holes exist in a range of technologies and languages for process integration and this can lead to customer dissatisfaction and failure to bring integration projects to reach their potential. Standards for process integration share similar fundamental flaws to languages and technologies. Standards are also in direct competition with other standards causing a lack of clarity. Thus the area of greatest risk in a BPM project remains process integration, despite major advancements in the technology base. This research examines some fundamental aspects of communication middleware and how these fundamental building blocks of integration can be brought to the process modelling layer in a technology agnostic manner. This way process modelling can be conceptually complete without becoming stuck in a particular middleware technology. Coloured Petri nets are used to define a formal semantics for the fundamental aspects of communication middleware. They provide the means to define and model the dynamic aspects of various integration middleware. Process integration patterns are used as a tool to codify common problems to be solved. Object Role Modelling is a formal modelling technique that was used to define the syntax of a proposed process integration language. This thesis provides several contributions to the field of process integration. It proposes a framework defining the key notions of integration middleware. This framework provides a conceptual foundation upon which a process integration language could be built. The thesis defines an architecture that allows various forms of middleware to be aggregated and reasoned about at the process layer. This thesis provides a comprehensive set of process integration patterns. These constitute a benchmark for the kinds of problems a process integration language must support. The thesis proposes a process integration modelling language and a partial implementation that is able to enact the language. A process integration pilot project in a German hospital is brie°y described at the end of the thesis. The pilot is based on ideas in this thesis.

Tests and Models of Non-compositional Concepts

The question of under what conditions conceptual representation is compositional remains debatable within cognitive science. This paper proposes a well developed mathematical apparatus for a probabilistic representation of concepts, drawing upon methods developed in quantum theory to propose a formal test that can determine whether a specific conceptual combination is compositional, or not. This test examines a joint probability distribution modeling the combination, asking whether or not it is factorizable. Empirical studies indicate that some combinations should be considered non-compositionally.

Emergent innovation through the co-evolution of informal and formal media economies

Well-established distinctions between amateur and professional are blurring as the impact of social media, changes in cultural consumption, and crises in copyright industries’ business models are felt across society and economy. I call this the increasingly rapid co-evolution of the formal market and informal household sectors and analyse it through the concept of ‘social network markets’ – individual choices are made on the basis of other’s choices and such networked preferencing is enhanced by the growing ubiquity of social media platforms. This may allow us better to understand sources of disruption and innovation in audiovisual production and distribution in wealthy Western markets which are as significant as those posed by informal practices outside the West. I examine what is happening around the monetization and professionalization of online video (YouTube, for example) and the socialization of professional production strategies (transmedia, for example) as innovation from the margins.

Emergency Health Services (EHS) : demand and service delivery models. monograph 3 : patients’ reasons and perceptions

Executive Summary Emergency health is a critical component of Australia’s health system and emergency departments (EDs) are increasingly congested from growing demand and blocked access to inpatient beds. The Emergency Health Services Queensland (EHSQ) study aims to identify the factors driving increased demand for emergency health and to evaluate strategies which may safely reduce the future demand growth. This monograph addresses the perspectives of users of both ambulance services and EDs. The research reported here aimed to identify the perspectives of users of emergency health services, both ambulance services and public hospital Emergency Departments and to identify the factors that they took into consideration when exercising their choice of location for acute health care. A cross-sectional survey design was used involving a survey of patients or their carers presenting to the EDs of a stratified sample of eight hospitals. A specific purpose questionnaire was developed based on a novel theoretical model which had been derived from analysis of the literature (Monograph 1). Two survey versions were developed: one for adult patients (self-complete); and one for children (to be completed by parents/guardians). The questionnaires measured perceptions of social support, health status, illness severity, self-efficacy; beliefs and attitudes towards ED and ambulance services; reasons for using these services, and actions taken prior to the service request. The survey was conducted at a stratified sample of eight hospitals representing major cities (four), inner regional (two) and outer regional and remote (two). Due to practical limitations, data were collected for ambulance and ED users within hospital EDs, while patients were waiting for or under treatment. A sample size quota was determined for each ED based on their 2009/10 presentation volumes. The data collection was conducted by four members of the research team and a group of eight interviewers between March and May 2011 (corresponding to autumn season). Of the total of 1608 patients in all eight emergency departments the interviewers were able to approach 1361 (85%) patients and seek their consent to participate in the study. In total, 911 valid surveys were available for analysis (response rate= 67%). These studies demonstrate that patients elected to attend hospital EDs in a considered fashion after weighing up alternatives and there is no evidence of deliberate or ill-informed misuse. • Patients attending ED have high levels of social support and self-efficacy that speak to the considered and purposeful nature of the exercise of choice. • About one third of patients have new conditions while two thirds have chronic illnesses • More than half the attendees (53.1%) had consulted a healthcare professional prior to making the decision. • The decision to seek urgent care at an ED was mostly constructed around the patient’s perception of the urgency and severity of their illness, reinforced by a strong perception that the hospital ED was the correct location for them (better specialised staff, better care for my condition, other options not as suitable). • 33% of the respondent held private hospital insurance but nevertheless attended a public hospital ED. Similarly patients exercised considered and rational judgements in their choice to seek help from the ambulance service. • The decision to call for ambulance assistance was based on a strong perception about the severity of the illness (too severe to use other means of transport) and that other options were not considered appropriate. • The decision also appeared influenced by a perception that the ambulance provided appropriate access to the ED which was considered most appropriate for their particular condition (too severe to go elsewhere, all facilities in one spot, better specialised and better care). • In 43.8% of cases a health care professional advised use of the ambulance. • Only a small number of people perceived that ambulance should be freely available regardless of severity or appropriateness. These findings confirm a growing understanding that the choice of professional emergency health care services is not made lightly but rather made by reasonable people exercising a judgement which is influenced by public awareness of the risks of acute health and which is most often informed by health professionals. It is also made on the basis of a rational weighing up of alternatives and a deliberate and considered choice to seek assistance from a service which the patient perceived was most appropriate to their needs at that time. These findings add weight to dispensing with public perceptions that ED and ambulance congestion is a result of inappropriate choice by patients. The challenge for health services is to better understand the patient’s needs and to design and validate services that meet those needs. The failure of our health system to do so should not be grounds for blaming the patient, claiming inappropriate patient choices.

Indexing and efficient instance-based retrieval of process models using untanglings

Process-Aware Information Systems (PAISs) support executions of operational processes that involve people, resources, and software applications on the basis of process models. Process models describe vast, often infinite, amounts of process instances, i.e., workflows supported by the systems. With the increasing adoption of PAISs, large process model repositories emerged in companies and public organizations. These repositories constitute significant information resources. Accurate and efficient retrieval of process models and/or process instances from such repositories is interesting for multiple reasons, e.g., searching for similar models/instances, filtering, reuse, standardization, process compliance checking, verification of formal properties, etc. This paper proposes a technique for indexing process models that relies on their alternative representations, called untanglings. We show the use of untanglings for retrieval of process models based on process instances that they specify via a solution to the total executability problem. Experiments with industrial process models testify that the proposed retrieval approach is up to three orders of magnitude faster than the state of the art.

Managing and learning with multiple models: Objectives and optimization algorithms

The quality of environmental decisions should be gauged according to managers' objectives. Management objectives generally seek to maximize quantifiable measures of system benefit, for instance population growth rate. Reaching these goals often requires a certain degree of learning about the system. Learning can occur by using management action in combination with a monitoring system. Furthermore, actions can be chosen strategically to obtain specific kinds of information. Formal decision making tools can choose actions to favor such learning in two ways: implicitly via the optimization algorithm that is used when there is a management objective (for instance, when using adaptive management), or explicitly by quantifying knowledge and using it as the fundamental project objective, an approach new to conservation.This paper outlines three conservation project objectives - a pure management objective, a pure learning objective, and an objective that is a weighted mixture of these two. We use eight optimization algorithms to choose actions that meet project objectives and illustrate them in a simulated conservation project. The algorithms provide a taxonomy of decision making tools in conservation management when there is uncertainty surrounding competing models of system function. The algorithms build upon each other such that their differences are highlighted and practitioners may see where their decision making tools can be improved. © 2010 Elsevier Ltd.

Improving wound management for residents in Residential Aged Care Facilities: National dissemination and implementation of the evidence based Champions for Skin Integrity Program

Overview The incidence of skin tears, pressure injuries and chronic wounds increases with age [1-4] and therefore is a serious issue for staff and residents in Residential Aged Care Facilities (RACFs). A pilot project funded in Round 2 of the Encouraging Best Practice in Residential Aged Care (EBPRAC) program by the then Australian Government Department of Health and Ageing found that a substantial proportion of residents in aged care facilities experienced pressure injuries, skin tears or chronic wounds. It also found the implementation of the evidence based Champions for Skin Integrity (CSI) model of wound care was successful in significantly decreasing the prevalence and severity of wounds in residents, improving staff skills and knowledge of evidence based wound management, increasing staff confidence with wound management, increasing implementation of evidence based wound management and prevention strategies, and increasing staff awareness of their roles in evidence based wound care at all levels [5]. Importantly, during the project, the project team developed a resource kit on evidence based wound management. Two critical recommendations resulting from the project were that: - The CSI model or a similar strategic approach should be implemented in RACFs to facilitate the uptake of evidence based wound management and prevention - The resource kit on evidence based wound management should be made available to all Residential Aged Care Facilities and interested parties A proposal to disseminate or rollout the CSI model of wound care to all RACFs across Australia was submitted to the department in 2012. The department approved funding from the Aged Care Services Improvement Healthy Ageing Grant (ACSIHAG) at the same time as the Round 3 of the Encouraging Better Practice in Aged Care (EBPAC) program. The dissemination involved two crucial elements: 1. The updating, refining and distribution of a Champions for Skin Integrity Resource Kit, more commonly known as a CSI Resource Kit and 2. The presentation of intensive one day Promoting Healthy Skin “Train the Trainer” workshops in all capital cities and major regional towns across Australia Due to demand, the department agreed to fund a second round of workshops focussing on regional centres and the completion date was extended to accommodate the workshops. Later, the department also decided to host a departmental website for a number of clinical domains, including wound management, so that staff from the residential aged care sector had easy access to a central repository of helpful clinical resource material that could be used for improving the health and wellbeing of their older adults, consumers and carers. CSI Resource Kit Upgrade and Distribution: At the start of the project, a full evidence review was carried out on the material produced during the EBPRAC-CSI Stage 1 project and the relevant evidence based changes were made to the documentation. At the same time participants in the EBPRAC-CSI Stage 1 project were interviewed for advice on how to improve the resource material. Following this the documentation, included in the kit, was sent to independent experts for peer review. When this process was finalised, a learning designer and QUT’s Visual Communications Services were engaged to completely refine and update the design of the resources, and combined resource kit with the goal of keeping the overall size of the kit suitable for bookshelf mounting and the cost at reasonable levels. Both goals were achieved in that the kit is about the same size as a 25 mm A4 binder and costs between $19.00 and $28.00 per kit depending on the size of the print run. The dissemination of the updated CSI resource kit was an outstanding success. Demand for the kits was so great that a second print run of 2,000 kits was arranged on top of the initial print run of 4,000 kits. All RACFs across Australia were issued with a kit, some 2,740 in total. Since the initial distribution another 1,100 requests for kits has been fulfilled as well as 1,619 kits being distributed to participants at the Promoting Healthy Skin workshops. As the project was winding up a final request email was sent to all workshop participants asking if they required additional kits or resources to distribute the remaining kits and resources. This has resulted in requests for 200 additional kits and resources. Feedback from the residential aged care sector and other clinical providers who have interest in wound care has been very positive regarding the utility of the kit, (see Appendix 4). Promoting Healthy Skin Workshops The workshops also exceeded the project team’s initial objective. Our goal of providing workshop training for staff from one in four facilities and 450 participants was exceeded, with overwhelming demand for workshop places resulting in the need to provide a second round of workshops across Australia. At the completion of the second round, 37 workshops had been given, with 1286 participants, representing 835 facilities. A number of strategies were used to promote the workshops ranging from invitations included in the kit, to postcard mail-outs, broadcast emailing to all facilities and aged care networks and to articles and paid advertising in aged care journals. The most effective method, by far, was directly phoning the facilities. This enabled the caller to contact the relevant staff member and enlist their support for the workshop. As this is a labour intensive exercise, it was only used where numbers needed bolstering, with one venue rising from 3 registrants before the calls to 53 registrants after. The workshops were aimed at staff who had the interest and the capability of implementing evidence-based wound management within their facility or organisation. This targeting was successful in that a large proportion (68%) of participants were Registered Nurses, Nurse Managers, Educators or Consultants. Twenty percent were Endorsed Enrolled Nurses with the remaining 12% being made up of Personal Care Workers or Allied Health Professionals. To facilitate long term sustainability, the workshop employed train-the-trainer strategies. Feedback from the EBPRAC-CSI Stage 1 interviews was used in the development of workshop content. In addition, feedback from the workshop conducted at the end of the EBPRAC-CSI Stage 1 project suggested that change management and leadership training should be included in the workshops. The program was trialled in the first workshop conducted in Brisbane and then rolled out across Australia. Participants were asked to complete pre and post workshop surveys at the beginning and end of the workshop to determine how knowledge and confidence improved over the day. Results from the pre and post surveys showed significant improvements in the level of confidence in attendees’ ability to implement evidence based wound management. The results also indicated a significant increase in the level of confidence in ability to implement change within their facility or organisation. This is an important indication that the inclusion of change management/leadership training with clinical instruction can increase staff capacity and confidence in translating evidence into practice. To encourage the transfer of the evidence based content of the workshop into practice, participants were asked to prepare an Action Plan to be followed by a simple one page progress report three months after the workshop. These reports ranged from simple (e.g. skin moisturising to prevent skin tears), to complex implementation plans for introducing the CSI model across the whole organisation. Outcomes described in the project reports included decreased prevalence of skin tears, pressure injuries and chronic wounds, along with increased staff and resident knowledge and resident comfort. As stated above, some organisations prepared large, complex plans to roll out the CSI model across their organisation. These plans included a review of the organisation’s wound care system, policies and procedures, the creation of new processes, the education of staff and clients, uploading education and resource material onto internal electronic platforms and setting up formal review and evaluation processes. The CSI Resources have been enthusiastically sought and incorporated into multiple health care settings, including aged care, acute care, Medicare Local intranets (e.g. Map of Medicine e-pathways), primary health care, community and home care organisations, education providers and New Zealand aged and community health providers. Recommendations: Recommendations for RACFs, aged care and health service providers and government  Skin integrity and the evidence-practice gap in this area should be recognised as a major health issue for health service providers for older adults, with wounds experienced by up to 50% of residents in aged care settings (Edwards et al. 2010). Implementation of evidence based wound care through the Champions for Skin Integrity model in this and the pilot project has demonstrated the prevalence of wounds, wound healing times and wound infections can be halved.  A national program and Centre for Evidence Based Wound Management should be established to: - expand the reach of the model to other aged care facilities and health service providers for older adults - sustain the uptake of models such as the Champions for Skin Integrity (CSI) model - ensure current resources, expertise and training are available for consumers and health care professionals to promote skin integrity for all older adults  Evidence based resources for the CSI program and similar projects should be reviewed and updated every 3 – 4 years as per NH&MRC recommendations  Leadership and change management training is fundamental to increasing staff capacity, at all levels, to promote within-organisation dissemination of skills and knowledge gained from projects providing evidence based training Recommendations for future national dissemination projects  A formal program of opportunities for small groups of like projects to share information and resources, coordinate activities and synergise education programs interactively would benefit future national dissemination projects - Future workshop programs could explore an incentive program to optimise attendance and reduce ‘no shows’ - Future projects should build in the capacity and funding for increased follow-up with workshop attendees, to explore the reasons behind those who are unable to translate workshop learnings into the workplace and identify factors to address these barriers.

Normative requirements for regulatory compliance: An abstract formal framework

By definition, regulatory rules (in legal context called norms) intend to achieve specific behaviour from business processes, and might be relevant to the whole or part of a business process. They can impose conditions on different aspects of process models, e.g., control-flow, data and resources etc. Based on the rules sets, norms can be classified into various classes and sub-classes according to their effects. This paper presents an abstract framework consisting of a list of norms and a generic compliance checking approach on the idea of (possible) execution of processes. The proposed framework is independent of any existing formalism, and provides a conceptually rich and exhaustive ontology and semantics of norms needed for business process compliance checking. The possible uses of the proposed framework include to compare different compliance management frameworks (CMFs).