849 resultados para network theory
Resumo:
Almost all metapopulation modelling assumes that connectivity between patches is only a function of distance, and is therefore symmetric. However, connectivity will not depend only on the distance between the patches, as some paths are easy to traverse, while others are difficult. When colonising organisms interact with the heterogeneous landscape between patches, connectivity patterns will invariably be asymmetric. There have been few attempts to theoretically assess the effects of asymmetric connectivity patterns on the dynamics of metapopulations. In this paper, we use the framework of complex networks to investigate whether metapopulation dynamics can be determined by directly analysing the asymmetric connectivity patterns that link the patches. Our analyses focus on “patch occupancy” metapopulation models, which only consider whether a patch is occupied or not. We propose three easily calculated network metrics: the “asymmetry” and “average path strength” of the connectivity pattern, and the “centrality” of each patch. Together, these metrics can be used to predict the length of time a metapopulation is expected to persist, and the relative contribution of each patch to a metapopulation’s viability. Our results clearly demonstrate the negative effect that asymmetry has on metapopulation persistence. Complex network analyses represent a useful new tool for understanding the dynamics of species existing in fragmented landscapes, particularly those existing in large metapopulations.
Resumo:
Calibration process in micro-simulation is an extremely complicated phenomenon. The difficulties are more prevalent if the process encompasses fitting aggregate and disaggregate parameters e.g. travel time and headway. The current practice in calibration is more at aggregate level, for example travel time comparison. Such practices are popular to assess network performance. Though these applications are significant there is another stream of micro-simulated calibration, at disaggregate level. This study will focus on such microcalibration exercise-key to better comprehend motorway traffic risk level, management of variable speed limit (VSL) and ramp metering (RM) techniques. Selected section of Pacific Motorway in Brisbane will be used as a case study. The discussion will primarily incorporate the critical issues encountered during parameter adjustment exercise (e.g. vehicular, driving behaviour) with reference to key traffic performance indicators like speed, lane distribution and headway; at specific motorway points. The endeavour is to highlight the utility and implications of such disaggregate level simulation for improved traffic prediction studies. The aspects of calibrating for points in comparison to that for whole of the network will also be briefly addressed to examine the critical issues such as the suitability of local calibration at global scale. The paper will be of interest to transport professionals in Australia/New Zealand where micro-simulation in particular at point level, is still comparatively a less explored territory in motorway management.
Resumo:
Calibration process in micro-simulation is an extremely complicated phenomenon. The difficulties are more prevalent if the process encompasses fitting aggregate and disaggregate parameters e.g. travel time and headway. The current practice in calibration is more at aggregate level, for example travel time comparison. Such practices are popular to assess network performance. Though these applications are significant there is another stream of micro-simulated calibration, at disaggregate level. This study will focus on such micro-calibration exercise-key to better comprehend motorway traffic risk level, management of variable speed limit (VSL) and ramp metering (RM) techniques. Selected section of Pacific Motorway in Brisbane will be used as a case study. The discussion will primarily incorporate the critical issues encountered during parameter adjustment exercise (e.g. vehicular, driving behaviour) with reference to key traffic performance indicators like speed, land distribution and headway; at specific motorway points. The endeavour is to highlight the utility and implications of such disaggregate level simulation for improved traffic prediction studies. The aspects of calibrating for points in comparison to that for whole of the network will also be briefly addressed to examine the critical issues such as the suitability of local calibration at global scale. The paper will be of interest to transport professionals in Australia/New Zealand where micro-simulation in particular at point level, is still comparatively a less explored territory in motorway management.
Resumo:
Measuring the business value that Internet technologies deliver for organisations has proven to be a difficult and elusive task, given their complexity and increased embeddedness within the value chain. Yet, despite the lack of empirical evidence that links the adoption of Information Technology (IT) with increased financial performance, many organisations continue to adopt new technologies at a rapid rate. This is evident in the widespread adoption of Web 2.0 online Social Networking Services (SNSs) such as Facebook, Twitter and YouTube. These new Internet based technologies, widely used for social purposes, are being employed by organisations to enhance their business communication processes. However, their use is yet to be correlated with an increase in business performance. Owing to the conflicting empirical evidence that links prior IT applications with increased business performance, IT, Information Systems (IS), and E-Business Model (EBM) research has increasingly looked to broader social and environmental factors as a means for examining and understanding the broader influences shaping IT, IS and E-Business (EB) adoption behaviour. Findings from these studies suggest that organisations adopt new technologies as a result of strong external pressures, rather than a clear measure of enhanced business value. In order to ascertain if this is the case with the adoption of SNSs, this study explores how organisations are creating value (and measuring that value) with the use of SNSs for business purposes, and the external pressures influencing their adoption. In doing so, it seeks to address two research questions: 1. What are the external pressures influencing organisations to adopt SNSs for business communication purposes? 2. Are SNSs providing increased business value for organisations, and if so, how is that value being captured and measured? Informed by the background literature fields of IT, IS, EBM, and Web 2.0, a three-tiered theoretical framework is developed that combines macro-societal, social and technological perspectives as possible causal mechanisms influencing the SNS adoption event. The macro societal view draws on the concept of Castells. (1996) network society and the behaviour of crowds, herds and swarms, to formulate a new explanatory concept of the network vortex. The social perspective draws on key components of institutional theory (DiMaggio & Powell, 1983, 1991), and the technical view draws from the organising vision concept developed by Swanson and Ramiller (1997). The study takes a critical realist approach, and conducts four stages of data collection and one stage of data coding and analysis. Stage 1 consisted of content analysis of websites and SNSs of many organisations, to identify the types of business purposes SNSs are being used for. Stage 2 also involved content analysis of organisational websites, in order to identify suitable sample organisations in which to conduct telephone interviews. Stage 3 consisted of conducting 18 in-depth, semi-structured telephone interviews within eight Australian organisations from the Media/Publishing and Galleries, Libraries, Archives and Museum (GLAM) industries. These sample organisations were considered leaders in the use of SNSs technologies. Stage 4 involved an SNS activity count of the organisations interviewed in Stage 3, in order to rate them as either Advanced Innovator (AI) organisations, or Learning Focussed (LF) organisations. A fifth stage of data coding and analysis of all four data collection stages was conducted, based on the theoretical framework developed for the study, and using QSR NVivo 8 software. The findings from this study reveal that SNSs have been adopted by organisations for the purpose of increasing business value, and as a result of strong social and macro-societal pressures. SNSs offer organisations a wide range of value enhancing opportunities that have broader benefits for customers and society. However, measuring the increased business value is difficult with traditional Return On Investment (ROI) mechanisms, ascertaining the need for new value capture and measurement rationales, to support the accountability of SNS adoption practices. The study also identified the presence of technical, social and macro-societal pressures, all of which influenced SNS adoption by organisations. These findings contribute important theoretical insight into the increased complexity of pressures influencing technology adoption rationales by organisations, and have important practical implications for practice, by reflecting the expanded global online networks in which organisations now operate. The limitations of the study include the small number of sample organisations in which interviews were conducted, its limited generalisability, and the small range of SNSs selected for the study. However, these were compensated in part by the expertise of the interviewees, and the global significance of the SNSs that were chosen. Future research could replicate the study to a larger sample from different industries, sectors and countries. It could also explore the life cycle of SNSs in a longitudinal study, and map how the technical, social and macro-societal pressures are emphasised through stages of the life cycle. The theoretical framework could also be applied to other social fad technology adoption studies.
Resumo:
Business Process Management (BPM) is a topic that continues to grow in significance as organisations seek to gain and sustain competitive advantage in an increasingly global environment. Despite anecdotal evidence of organisations improving performance by pursuing a BPM approach, there is little theory that explains and substantiates this relationship. This study provides the first theory on the progression and maturity of BPM Initiatives within organisations and provides a vital starting block upon which future research in this area can build. The Researcher starts by clearly defining three key terms (BPM Initiative, BPM Progression and BPM Maturity), showing the relationship between these three concepts and proposing their relationship with Organisational Performance. The Researcher then combines extant literature and use of the Delphi Technique and the case study method to explore the progression and measurement of the BPM Initiatives within organisations. The study builds upon the principles of general theories including the Punctuated Equilibrium Model and Dynamic Capabilities to present theory on BPM Progression and BPM Maturity. Using the BPM Capability Framework developed through an international Delphi study series, the Researcher shows how the specific organisational context influences which capability areas an organisation chooses to progress. By comparing five separate organisations over an extended time the Researcher is able to show that, despite this disparity, there is some evidence of consistency with regard to the capability areas progressed. This suggests that subsequent identification of progression paths may be possible. The study also shows that the approach and scope taken to BPM within each organisation is a likely predictor of such paths. These outcomes result in the proposal of a formative model for measuring BPM Maturity.
Resumo:
There is a lack of writing on the issue of the education rights of people with disabilities by authors of any theoretical persuasion. While the deficiency of theory may be explained by a variety of historical, philosophical and practical considerations, it is a deficiency which must be addressed. Otherwise, any statement of rights rings out as hollow rhetoric unsupported by sound reason and moral rectitude. This paper attempts to address this deficiency in education rights theory by postulating a communitarian theory of the education rights of people with disabilities. The theory is developed from communitarian writings on the role of education in democratic society. The communitarian school, like the community within which it nests, is inclusive. Schools both reflect and model the shape of communitarian society and have primary responsibility for teaching the knowledge and virtues which will allow citizens to belong to and function within society. Communitarians emphasise responsibilities, however, as the corollary of rights and require the individual good to yield to community good when the hard cases arise. The article not only explains the basis of the right to an inclusive education, therefore, but also engages with the difficult issue of when such a right may not be enforceable.
Resumo:
Queensland's new State Planning Policy for Coastal Protection, released in March and approved in April 2011 as part of the Queensland Coastal Plan, stipulates that local governments prepare and implement adaptation strategies for built up areas projected to be subject to coastal hazards between present day and 2100. Urban localities within the delineated coastal high hazard zone (as determined by models incorporating a 0.8 meter rise in sea level and a 10% increase in the maximum cyclone activity) will be required to re-evaluate their plans to accommodate growth, revising land use plans to minimise impacts of anticipated erosion and flooding on developed areas and infrastructure. While implementation of such strategies would aid in avoidance or minimisation of risk exposure, communities are likely to face significant challenges in such implementation, especially as development in Queensland is so intensely focussed upon its coasts with these new policies directing development away from highly desirable waterfront land. This paper examines models of planning theory to understand how we plan when faced with technically complex problems towards formulation of a framework for evaluating and improving practice.
Resumo:
The concept of knowledge-based urban development has first come to the urban planning and development agenda during the very last years of the 20th century as a promising paradigm to support the transformation process of cities into knowledge cities and their societies into knowledge societies. However, soon after the exponentially rapid advancements experienced, during the first decade of the 21st century, particularly, in the domains of economy, society, management and technology along with the severe impacts of climate change, have made the redefinition of the term a necessity. This paper, first, reports the findings of the review of the relatively short but dynamic history of urbanisation experiences of our cities around the globe. The paper, then, focuses on the 21st century urbanisation context and discusses the conceptual base of the knowledge-based development of cities and how this concept found application ground in many parts of the world. Following this, the paper speculates development of future cities by particularly highlighting potential challenges and opportunities that previously have not been fully considered. This paper, lastly, introduces and elaborates how relevant theories support the better conceptualisation of this relatively new, but rapidly emerging paradigm, and redefines it accordingly.
Resumo:
Using a thematic story telling approach which draws on ethnographic method, a grounded theory of protest movement continuity is presented. The grounded theory draws from theories and activist stories relating to the facilitative role of movement networks, social contagion theory and the cultural experience of activism. It highlights the contagious influence of protest networks in maintaining protest continuity over time and how this leads to common perceptions of development risk and opportunity within communities. It also reveals how communities use collective values and identity, social capital, emotional dynamics and symbolic artifacts to maintain protest continuity.
Resumo:
This article augments Resource Dependence Theory with Real Options reasoning in order to explain time bounds specification in strategic alliances. Whereas prior work has found about a 50/50 split between alliances that are time bound and those that are open-ended, their substantive differences and antecedents are ill understood. To address this, we suggest that the two alliance modes present different real options trade-offs in adaptation to environmental uncertainty: ceteris paribus, time-bound alliances are likely to provide abandonment options over open-ended alliances, but require additional investments to extend the alliance when this turns out to be desirable after formation. Open-ended alliances are likely to provide growth options over open-ended alliances, but they demand additional effort to abandon the alliance if post-formation circumstances so desire. Therefore, we expect time bounds specification to be a function of environmental uncertainty: organizations in more uncertain environments will be relatively more likely to place time bounds on their strategic alliances. Longitudinal archival and survey data collected amongst 39 industry clusters provides empirical support for our claims, which contribute to the recent renaissance of resource dependence theory by specifying the conditions under which organizations choose different time windows in strategic partnering.
Resumo:
Resilient organised crime groups survive and prosper despite law enforcement activity, criminal competition and market forces. Corrupt police networks, like any other crime network, must contain resiliency characteristics if they are to continue operation and avoid being closed down through detection and arrest of their members. This paper examines the resilience of a large corrupt police network, namely The Joke which operated in the Australian state of Queensland for a number of decades. The paper uses social network analysis tools to determine the resilient characteristics of the network. This paper also assumes that these characteristics will be different to those of mainstream organised crime groups because the police network operates within an established policing agency rather than as an independent entity hiding within the broader community.
Resumo:
There appears no shortage of theorists for preservice teacher education; however many ideas are abandoned without practical applications. Indeed, it can take years for theories to materialise into practice, if they materialise at all. The quality of preservice teacher education is central for enhancing an education system, and mentors’ roles can assist to shape preservice teachers’ development within the school context. Yet mentoring can be haphazard without being underpinned by a theoretical framework. A mentoring model (personal attributes, system requirements, pedagogical knowledge, modelling, and feedback) has emerged from research and the literature to guide mentors’ practices. This qualitative study investigates mentors’ pedagogical knowledge as one factor crucial to the mentoring process. More specifically, this study involves a questionnaire and audio-recorded focus group meetings with experienced mentors (n=14) who deliberated on devising practical applications for mentoring pedagogical knowledge. Findings revealed that these experienced mentors pinpointed practical applications around a mentor’s role for providing pedagogical knowledge to the mentee. These strategies were varied and demonstrated that any one mentoring practice may be approached from a number of different angles. Nevertheless, there were core mentoring practices in pedagogical knowledge such as showing the mentee how to plan for teaching, articulating classroom management approaches, and talking about how to connect learning to assessment. Mentors may require education on current mentoring practices with practical strategies that are linked to theoretical underpinnings.
Resumo:
The business environment across the globe is today characterised by three primary governance arrangements - bureaucracies, markets and networks. For organisations operating within each of these business contexts the terms of engagement in regard to negotiation are different. Rather than starting from a broad ‘how to’ approach or a specific cultural interface, Negotiating the Business Environment looks at governance arrangements within the business environment and at how such governance arrangements impact on how negotiation occurs. This text provides an Australian—not an overseas—perspective on negotiations that will be a welcome change for Australian students. Uniquely, it takes into account the context in which negotiations take place. Negotiating the Business Environment demonstrates how responding to business style in negotiations can effect successful outcomes. It include strong pedagogy including: key terms, key points, further reading lists, case studies, and end of chapter questions
Resumo:
Collaboration has been enacted as a core strategy by both the government and nongovernment sectors to address many of the intractable issues confronting contemporary society. The cult of collaboration has become so pervasive that it is now an elastic term referring generally to any form of ‘working together’. The lack of specificity about collaboration and its practice means that it risks being reduced to mere rhetoric without sustained practice or action. Drawing on an extensive data set (qualitative, quantitative) of broadly collaborative endeavours gathered over ten years in Queensland, Australia, this paper aims to fill out the black box of collaboration. Specifically it examines the drivers for collaboration, dominant structures and mechanisms adopted, what has worked and unintended consequences. In particular it investigates the skills and competencies required in an embeded collaborative endeavour within and across organisations. Social network analysis is applied to isolate the structural properties of collaborations over other forms of integration as well as highlighting key roles and tasks. Collaboration is found to be a distinctive form of working together, characterised by intense and interdependent relationships and exchanges, higher levels of cohesion (density) and requiring new ways of behaving, working, managing and leading. These elements are configured into a practice framework. Developing an empirical evidence base for collaboration structure, practice and strategy provides a useful foundation for theory extension. The paper concludes that for collaboration, to be successfully employed as a management strategy it must move beyond rhetoric and develop a coherent model for action.