25,345 research outputs found

    Constraining the Number of Positive Responses in Adaptive, Non-Adaptive, and Two-Stage Group Testing

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    Group testing is a well known search problem that consists in detecting the defective members of a set of objects O by performing tests on properly chosen subsets (pools) of the given set O. In classical group testing the goal is to find all defectives by using as few tests as possible. We consider a variant of classical group testing in which one is concerned not only with minimizing the total number of tests but aims also at reducing the number of tests involving defective elements. The rationale behind this search model is that in many practical applications the devices used for the tests are subject to deterioration due to exposure to or interaction with the defective elements. In this paper we consider adaptive, non-adaptive and two-stage group testing. For all three considered scenarios, we derive upper and lower bounds on the number of "yes" responses that must be admitted by any strategy performing at most a certain number t of tests. In particular, for the adaptive case we provide an algorithm that uses a number of "yes" responses that exceeds the given lower bound by a small constant. Interestingly, this bound can be asymptotically attained also by our two-stage algorithm, which is a phenomenon analogous to the one occurring in classical group testing. For the non-adaptive scenario we give almost matching upper and lower bounds on the number of "yes" responses. In particular, we give two constructions both achieving the same asymptotic bound. An interesting feature of one of these constructions is that it is an explicit construction. The bounds for the non-adaptive and the two-stage cases follow from the bounds on the optimal sizes of new variants of d-cover free families and (p,d)-cover free families introduced in this paper, which we believe may be of interest also in other contexts

    Integrating knowledge accross disciplines. Experiences from the NeWater project

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    The starting question for this deliverable was how to create a new adaptive management concept that can integrate insights from various disciplines and connect people from different institutional backgrounds. From literature research and empirical research on the NeWater project we identified challenges for cross-disciplinary knowledge integration, we evaluated interventions for connecting multiple knowledge frames, we analyzed the process of group model building with UML and formulated recommendations. Cross-disciplinary research has arisen from a growing number of complex problems for which knowledge of a single scientific discipline or societal field is insufficient, but presents important challenges: (1) collaboration and integration of knowledge requires in depth discussions that are timeconsuming; (2) the recursive process of problem structuring and restructuring is often at odds with the sequential planning of project activities; (3) participation and mutual learning are crucial but need to be carefully structured and sequenced; and (4) management and leadership faces the difficult challenge of balancing in depth exploration with timely delivery of tangible results. We conclude with the following general recommendations for large cross-disciplinary projects: (1) including a preparatory proposal phase for thorough exploration of opportunities of between researchers and stakeholders (2) flexible funding, planning and operational arrangements to allow for a recursive research process; (3) a project size that allows frequent interaction opportunities between researchers and between researchers and stakeholders to allow for mutual learning and in depth exploration; and (4) enhancing learning opportunities from one project to the next

    Review of Key Stage 2 testing, assessment and accountability Progress Report

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    Job Satisfaction and Subjective Well-Being As Determinants of Job Adaptation

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    An important controversy in the literature on employee withdrawal/adaptation concerns whether job satisfaction predicts behaviors that are manifestations of this construct. Although the area has not lacked for empirical research, Hulin (1991) has argued that several unresolved issues have limited the generalizations we can make about the role of job satisfaction in influencing isolated work behaviors. Hulin (1991) hypothesized that there is a general construct underlying many adaptive behaviors, including job withdrawal. When this general construct is assessed through combination of individual behaviors, the ability of constructs such as job satisfaction to influence job adaptation was hypothesized to increase over the prediction of specific behaviors. In the present study, individual behaviors thought to represent the adaptation construct were obtained through three different sources of data. Job satisfaction, subjective well-being, and other variables were hypothesized to influence the adaptation construct within the framework of a causal model. Results indicated support for both the job adaptation construct and its relation to job satisfaction and subjective well-being

    Adaptive Governance and Evolving Solutions to Natural Resource Conflicts

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    New Zealand is facing increasing challenges in managing natural resources (land, freshwater, marine space and air quality) under pressures from domestic (population growth, agricultural intensification, cultural expectations) and international (climate change) sources. These challenges can be described in terms of managing ‘wicked problems’; i.e. problems that may not be understood fully until they have been solved, where stakeholders have different world views and frames for understanding the problem, the constraints affecting the problem and the resources required to solve it change over time, and no complete solution is ever actually found. Adaptive governance addresses wicked problems through a framework to engage stakeholders in a participative process to create a long term vision. The vision must identify competing goals and a process for balancing them over time that acknowledges conflicts cannot always be resolved in a single lasting decision. Circumstances, goals and priorities can all vary over time and by region. The Resource Management Act can be seen as an adaptive governance structure where frameworks for resources such as water may take years to evolve and decades to fully implement. Adaptive management is about delivery through an incremental/experimental approach, limits on the certainty that governments can provide and stakeholders can demand, and flexibility in processes and results. In New Zealand it also requires balancing central government expertise and resources, with local authorities which can reflect local goals and knowledge, but have varying resources and can face quite distinct issues of widely differing severity. It is important to signal the incremental, overlapping, iterative and time-consuming nature of the work involved in developing and implementing adaptive governance and management frameworks. Managing the expectations of those involved as to the nature of the process and their role in it, and the scope and timing of likely outcomes, is key to sustaining participation.Adaptive capacity; governance; resilience

    Supporting evidence-based adaptation decision-making in South Australia: a synthesis of climate change adaptation research

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    This research synthesis provides policy-makers and practitioners with an understanding of the building blocks for effective adaptation decision-making, as evidenced through the NCCARF research program. It synthesised a portfolio of adaptation research for each Australian state and territory and addressing the complex relationships between research and policy development.   Each state and territory synthesis report directs users to research relevant identified priorities
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