29,287 research outputs found

    Applying trait-based models to achieve functional targets for theory-driven ecological restoration

    Get PDF
    Manipulating community assemblages to achieve functional targets is a key component of restoring degraded ecosystems. The response-and-effect trait framework provides a conceptual foundation for translating restoration goals into functional trait targets, but a quantitative framework has been lacking for translating trait targets into assemblages of species that practitioners can actually manipulate. This study describes new trait-based models that can be used to generate ranges of species abundances to test theories about which traits, which trait values and which species assemblages are most effective for achieving functional outcomes. These models are generalisable, flexible tools that can be widely applied across many terrestrial ecosystems. Examples illustrate how the framework generates assemblages of indigenous species to (1) achieve desired community responses by applying the theories of environmental filtering, limiting similarity and competitive hierarchies, or (2) achieve desired effects on ecosystem functions by applying the theories of mass ratios and niche complementarity. Experimental applications of this framework will advance our understanding of how to set functional trait targets to achieve the desired restoration goals. A trait-based framework provides restoration ecology with a robust scaffold on which to apply fundamental ecological theory to maintain resilient and functioning ecosystems in a rapidly changing world

    An introduction to the constraints-led approach to learning in outdoor education

    Get PDF
    Participation in outdoor education is underpinned by a learner's ability to acquire skills in activities such as canoeing, bushwalking and skiing and consequently the outdoor leader is often required to facilitate skill acquisition and motor learning. As such, outdoor leaders might benefit from an appropriate and tested model on how the learner acquires skills in order to design appropriate learning contexts. This paper introduces an approach to skill acquisition based on ecological psychology and dynamical systems theory called the constraints-led approach to skills acquisition. We propose that this student-centred approach is an ideal perspective for the outdoor leader to design effective learning settings. Furthermore, this open style of facilitation is also congruent with learning models that focus on other concepts such as teamwork and leadership

    Automatic allocation of safety requirements to components of a software product line

    Get PDF
    Safety critical systems developed as part of a product line must still comply with safety standards. Standards use the concept of Safety Integrity Levels (SILs) to drive the assignment of system safety requirements to components of a system under design. However, for a Software Product Line (SPL), the safety requirements that need to be allocated to a component may vary in different products. Variation in design can indeed change the possible hazards incurred in each product, their causes, and can alter the safety requirements placed on individual components in different SPL products. Establishing common SILs for components of a large scale SPL by considering all possible usage scenarios, is desirable for economies of scale, but it also poses challenges to the safety engineering process. In this paper, we propose a method for automatic allocation of SILs to components of a product line. The approach is applied to a Hybrid Braking System SPL design

    Historical forest biomass dynamics modelled with Landsat spectral trajectories

    Get PDF
    Acknowledgements National Forest Inventory data are available online, provided by Ministerio de Agricultura, Alimentación y Medio Ambiente (España). Landsat images are available online, provided by the USGS.Peer reviewedPostprin

    Sources of real and nominal exchange rate fluctuations in transition economies

    Get PDF
    This paper provides an empirical inquiry into the sources of movements of the real and nominal exchange rates in Hungary and Poland for during the 1990:01-1998:02 period. We decompose the exchange rate movements into those attributable to real and nominal shocks, we find that (1) nominal shocks have played a significant role in Poland, but not in Hungary, in explaining real exchange rate movements during the transition period. Instead, real shocks have dominated real exchange movements in Hungary and (2) nominal shocks explain almost all of nominal exchange rate movements in Poland and a sizable portion of nominal exchange rate movements in Hungary. These results are compared with the findings of Lastrapes (1992) and Enders and Lee (1997) for industrial countries. Finally, policy implications of the empirical results as well their lessons for modeling exchange rates in transition economies are discussed.Poland ; Hungary ; Econometric models

    Case Study on Design Management: Inefficiencies and Possible Remedies

    Get PDF
    Delivering better products with a reduced lead time and less resources has become the primary focus of design management. The aim of this work is to revisit typical design management inefficiencies and discuss possible remedies for these problems. To this end, a case study and interviews with seven Estonian architects were carried out. The data obtained was analyzed within the framework of the transformation-flow-value theory of production. Despite its failure to deliver customer value, a single-minded transformation view of operations has been the dominant approach taken in design management and processes, leading to inefficiencies in design practices

    Perturbation Analysis for Robust Damage Detection with Application to Multifunctional Aircraft Structures

    Get PDF
    The most widely known form of multifunctional aircraft structure is smart structures for structural health monitoring (SHM). The aim is to provide automated systems whose purposes are to identify and to characterize possible damage within structures by using a network of actuators and sensors. Unfortunately, environmental and operational variability render many of the proposed damage detection methods difficult to successfully be applied. In this paper, an original robust damage detection approach using output-only vibration data is proposed. It is based on independent component analysis and matrix perturbation analysis, where an analytical threshold is proposed to get rid of statistical assumptions usually performed in damage detection approach. The effectiveness of the proposed SHM method is demonstrated numerically using finite element simulations and experimentally through a conformal load-bearing antenna structure and composite plates instrumented with piezoelectric ceramic materials.FUI MSIE (Pole Astech

    A diversity-based approach to requirements tracing in new product development.

    Get PDF
    Production models emerged in recent times have stressed the need to face complex production contexts, characterized in particular by the rise in internal and environmental variability. In this work, a stylization of some elements concerning analysis and design of new products is given, and in particular those that involve definition and transfer phases in the development of innovative goods, where change and variability in requirements along development process are often high. This analysis has a twofold goal: first, to supply a conceptual frame for the close examination of some dynamics of requirement's integration into an artifact's design, in order to give account of their variability along development cycle; on the other side, to propose an approach based on simple similarity metrics, to be applied to linguistic descriptions of artifacts in the early phases of development process, in order to identify components in an artifact that undergo larger variability and therefore are to be paid more attention in the subsequent phases of life cycle.
    corecore