5,454 research outputs found

    Optimal monetary impulse-response functions in a matching model

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    The effects on ex ante optima of a lag in seeing monetary realizations are studied using a matching model of money. The main new ingredient in the model is meetings in which producers have more information than consumers. A consequence is that increases in the amount of money that occur with small enough probability can have negative impact effects on output, because it is optimal to shut down trade in such low probability meetings rather than have lower output when high probability realizations occur. The information lag also produces prices that do not respond much to current monetary realizations.Money supply ; Prices ; Production (Economic theory)

    Optimal Monetary Impulse-Response Functions in a Matching Model

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    The effects on ex ante optima of a lag in seeing monetary realizations are studied using a matching model of money. The main new ingredient in the model is meetings in which producers have more information than consumers. A consequence is that increases in the amount of money that occur with small enough probability can have negative impact effects on output, because it is optimal to shut down trade in such low probability meetings rather than have lower output when high probability realizations occur. The information lag also produces prices that do not respond much to current monetary realizations.

    Real-Time Planning with Multi-Fidelity Models for Agile Flights in Unknown Environments

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    Autonomous navigation through unknown environments is a challenging task that entails real-time localization, perception, planning, and control. UAVs with this capability have begun to emerge in the literature with advances in lightweight sensing and computing. Although the planning methodologies vary from platform to platform, many algorithms adopt a hierarchical planning architecture where a slow, low-fidelity global planner guides a fast, high-fidelity local planner. However, in unknown environments, this approach can lead to erratic or unstable behavior due to the interaction between the global planner, whose solution is changing constantly, and the local planner; a consequence of not capturing higher-order dynamics in the global plan. This work proposes a planning framework in which multi-fidelity models are used to reduce the discrepancy between the local and global planner. Our approach uses high-, medium-, and low-fidelity models to compose a path that captures higher-order dynamics while remaining computationally tractable. In addition, we address the interaction between a fast planner and a slower mapper by considering the sensor data not yet fused into the map during the collision check. This novel mapping and planning framework for agile flights is validated in simulation and hardware experiments, showing replanning times of 5-40 ms in cluttered environments.Comment: ICRA 201

    Diversity and biosynthetic potential of culturable microbes associated with toxic marine animals

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    Tetrodotoxin (TTX) is a neurotoxin that has been reported from taxonomically diverse organisms across 14 different phyla. The biogenic origin of tetrodotoxin is still disputed, however, TTX biosynthesis by host-associated bacteria has been reported. An investigation into the culturable microbial populations from the TTX-associated blue-ringed octopus Hapalochlaena sp. and sea slug Pleurobranchaea maculata revealed a surprisingly high microbial diversity. Although TTX was not detected among the cultured isolates, PCR screening identifiedsome natural product biosynthesis genes putatively involved in its assembly. This study is the first to report on the microbial diversity of culturable communities from H. maculosa and P. maculata and common natural product biosynthesis genes from their microbiota. We also reassess the production of TTX reported from three bacterial strains isolated from the TTX-containing gastropod Nassarius semiplicatus

    Systematic Regional Planning for Multiple Objective Natural Resource Management. A Case Study in the South Australian River Murray Corridor.

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    The aim of this study is to assess the feasibility of different policy options for encouraging the large scale NRM actions required for achieving stated regional resource condition targets for NRM. To achieve this, the concept of systematic regional planning is developed to identify geographic priorities for NRM actions that most cost effectively meet multiple-objective regional targets based on established biophysical and economic principles.Water;Australia;Rivers;Biodiversity;Natural Resource Management;Revegetation

    Exploring the Cost Effectiveness of Land Conservation Auctions and Payment Policies

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    Until recently public efforts to encourage conservation on private land in many countries has primarily been through uniform payment policies. Auctions are increasingly used as a payment mechanism to acquire public benefits such as conservation actions that provide environmental improvements on private land (e.g. the US Conservation Reserve Program (CRP). The economic rationale for use of auctions is that they create decentralised incentives to offer bids at close to the true landholder opportunity costs, even when the implementing agency holds little information about these opportunity costs. This paper assesses the cost of a case study auction relative to four payment policies that use varying levels of information strategically to reduce rent payment and to prioritise funding based on environmental value. The results suggest that the estimated cost savings achievable with the discriminant price auction for conservation contracts depends on the policy to which the auction outcomes are compared. Auction cost savings are likely to be greatest when compared to policy alternatives involving little effort to discriminate amongst offers based on differences in landholder opportunity costs. A further key finding is that, for this case study, most of the savings resulting from the discriminant price auction could be attributed to the use of the environmental benefits index in project ranking and selection.Land Economics/Use,
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