845 research outputs found

    Public participation and willingness to cooperate in common-pool resource management: a field experiment with fishing communities in Brazil

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    The primary evidence about the factors determining successful self-governance of common-pool resources (CPR) has come from case studies. More recently, this observational evidence has been complemented by insights from economic experiments. Here we advance a third approach in which the role of local deliberation about the management of a fishery resource is investigated in a field experiment. Using three control and three treatment communities in a freshwater fishery, we tested if participation in developing specific measures for community-based sustainable CPR management increased the willingness to contribute to the implementation of these measures. Each community was also exposed to information about their community leader's advice about the proposed measures. Both participation and leader advice affected the willingness of participants to contribute to one of three concrete proposals. However, the strongest influence on individual willingness to contribute was exerted by the individual beliefs about the cooperation of others in CPR management. --local deliberation,participatory research,willingness to contribute,beliefs,fishing resources,field experiment

    The influence of geometry on the stress distribution in joints

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    The Camp View of Inflation Forecasts

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    Analyzing sample moments of survey forecasts, we derive disagreement and un- certainty measures for the short- and medium term inflation outlook. The latter provide insights into the development of inflation forecast uncertainty in the context of a changing macroeconomic environment since the beginning of 2008. Motivated by the debate on the role of monetary aggregates and cyclical variables describing a Phillips-curve logic, we develop a macroeconomic indicator spread which is assumed to drive forecasters’ judgments. Empirical evidence suggests procyclical dynamics between disagreement among forecasters, individual forecast uncertainty and the macro-spread. We call this approach the camp view of inflation forecasts and show that camps form up whenever the spread widens.monetary policy, survey forecasts, inflation uncertainty, heterogenous beliefs and expectations, monetary aggregates

    Spectral Estimates and Non-Selfadjoint Perturbations of Spheroidal Wave Operators

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    We derive a spectral representation for the oblate spheroidal wave operator which is holomorphic in the aspherical parameter Ω\Omega in a neighborhood of the real line. For real Ω\Omega, estimates are derived for all eigenvalue gaps uniformly in Ω\Omega. The proof of the gap estimates is based on detailed estimates for complex solutions of the Riccati equation. The spectral representation for complex Ω\Omega is derived using the theory of slightly non-selfadjoint perturbations.Comment: 33 pages, LaTeX, 3 figures, typo in Lemma 4.1 corrected (published version

    Local reference filter for life-long vision aided inertial navigation

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    Filter based system state estimation is widely used for hard-realtime applications. In long-term filter operation the estimation of unobservable system states can lead to numerical instability due to unbounded state uncertainties. We introduce a filter concept that estimates system states in respect to changing local references instead of one global reference. In this way unbounded state covariances can be reset in a consistent way. We show how local reference (LR) filtering can be integrated into filter prediction to be used in square root filter implementations. The concept of LR-filtering is applied to the problem of vision aided inertial navigation (LR-INS). The results of a simulated 24 h quadrotor flight using the LR-INS demonstrate longterm filter stability. Real quadrotor flight experiments show the usability of the LR-INS for a highly dynamic system with limited computational resources

    Driving style for better fuel economy

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    Driving style has emerged as an important determinant of fuel economy. There is now evidence that driving style can be influenced to improve fuel economy as well as other aspects such as safety. However, it is not clear which are the most appropriate and influential factors that affect an individual's, or a group's, driving style with respect to improving fuel economy. In this paper, such factors were identified from the literature and by way of driver training programmes for fuel economy. The factors were then categorised under driver factors, operating the vehicle, vehicle dynamics and driver awareness. The influences of the factors on fuel economy were prioritised using a multi-criteria analysis method called the analytical hierarchy process to determine their relative importance. It was found that driver awareness, measured in terms of culture change and better management, was considered the most influential category. The second most influential category of factors concerned operating the vehicle or vehicle control where acceleration and speed were dominant. The driver-related factors were considered to have the least influence on fuel economy. The results can be used to improve interventions such as driver training by emphasising the most influential driving factors. </jats:p

    State-of-the-art in managing reliability in mega railway projects.:A systematic literature review

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    Mega Railway Projects (MRPs) are expensive and account for an increasing per-centage of many a nation’s annual infrastructure expenditure. These MRPs fre-quently exceed their budget and schedule. The challenge of achieving reliability or availability targets stands out as a contributing factor to these overruns. A robust and targeted Reliability, Availability, and Maintainability (RAM) process, which covers systems and subsystems that comprise the railway, that is imbedded in the project from the outset and that is managed throughout the life cycle of the project, is crucial for success. However, a RAM process for MRPs is not readily available. While BS EN 50126-11sets out the required RAM related tasks there is no guidance on how these tasks are to be undertaken or managed. This omission is likely to increase the challenge faced by RAM or Systems engineers as they put forth their case for ring-fenced funds and labour at the outset of an MRP. It is therefore important that RAM on an MRP is reviewed so that next steps in devel-oping robust RAM process plan guidelines can be determined. The authors of this paper discuss why RAM is undertaken and the conceptualisation of RAM along with its fundamental features. Its application on railways focusing on RAM techni-ques and BS EN 50126-1 is outlined. A Systematic Literature Review (SLR) is under-taken to show the state-of-the-art by using a meta and content analysis within the context of railway systems, RAM techniques, RAM standards and Reliability levels. Furthermore, a set of Derived RAM requirements (DRR) based on BS EN 50126-1 are derived to determine the critical areas of RAM and are thus recommended for further development by researchers or RAM practitioner

    The camp view of inflation forecasts

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    Analyzing sample moments of survey forecasts, we derive disagreement and un- certainty measures for the short- and medium term inflation outlook. The latter provide insights into the development of inflation forecast uncertainty in the context of a changing macroeconomic environment since the beginning of 2008. Motivated by the debate on the role of monetary aggregates and cyclical variables describing a Phillips-curve logic, we develop a macroeconomic indicator spread which is assumed to drive forecasters? judgments. Empirical evidence suggests procyclical dynamics between disagreement among forecasters, individual forecast uncertainty and the macro-spread. We call this approach the camp view of inflation forecasts and show that camps form up whenever the spread widens
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