6,052 research outputs found

    Applying MAPP Algorithm for Cooperative Path Finding in Urban Environments

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    The paper considers the problem of planning a set of non-conflict trajectories for the coalition of intelligent agents (mobile robots). Two divergent approaches, e.g. centralized and decentralized, are surveyed and analyzed. Decentralized planner - MAPP is described and applied to the task of finding trajectories for dozens UAVs performing nap-of-the-earth flight in urban environments. Results of the experimental studies provide an opportunity to claim that MAPP is a highly efficient planner for solving considered types of tasks

    Managing the Energy Trilemma in the Philippines

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    Background The transition to an energy mix with lower carbon emissions is hampered by the existence of the so-called Energy Trilemma. The primary consequence is a trade-off between various objectives of energy policy, e.g., equity and sustainability. This conflict can lead to policy gridlock if policymakers are unable to prioritize the goals. This paper proposes a framework and methodology to manage the trilemma by applying methods related to multi-criteria decision-making in order to assign weights to the various components of the trilemma. Results Following the International Energy Agency (IEA), an expanded concept of energy security is adopted and translates to a version of the trilemma different from that of the World Energy Council. This study takes into account autarky, price, supply, and carbon emissions. The values of these variables are generated by a software called PLEXOS and are incorporated in a welfare function. Trade-offs and complementarities among the four variables are taken into account by the equations in the PLEXOS model. Meanwhile, weights for each of the components of the trilemma are obtained using the Analytical Hierarchy Process. The experts interviewed for this exercise are considered hypothetical heads of the Philippine Department of Energy (DOE). Conclusion Two scenarios were compared: a market-based simulation and one where a carbon-tax was imposed. As expected, the carbon-tax leads to a fall in the level of carbon emissions but a rise in the cost of electricity. Because the demand for electricity has a higher price elasticity among lower income classes, the carbon-tax will worsen equity. Attempting to resolve the conflict among the goals of energy policy is difficult leading to a possible gridlock. Policy options can, however, be ranked using the values generated by the welfare function. The ranking clearly depends on the preference or priorities of the hypothetical head of the DOE but at least a decision could be reached. In this manner, trade-offs are measured and the trilemma can be managed even if it is not resolved

    Evaluating the Feed-in Tariff Policy in the Philippines

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    To address the problems of climate change and energy security, the Philippines enacted the Renewable Energy (RE) Act of 2008. The law mandated the Feed-In Tariff (FiT) policy, which was designed to provide a guaranteed fixed price to RE investors for 20 years to develop renewable technology. This paper aims to evaluate the effectiveness of the FiT policy in promoting renewable energy development in the Philippines by assessing its costs and benefits. Data show that while the FiT has led to an increase in RE generating capacity, the share of renewable energy in the country has been declining since 2011. The findings also suggest that the Philippines has incurred a net social cost from its implementation of the FiT.   Keywords: Feed-in Tariff, Electricity, Policy Evaluation, Philippines, Renewable Energy JEL Classifications: Q40, Q48 DOI: https://doi.org/10.32479/ijeep.1132

    VE-cadherin and claudin-5: it takes two to tango

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    Endothelial barrier function requires the adhesive activity of VE-cadherin and claudin-5, which are key components of adherens and tight endothelial junctions, respectively. Emerging evidence suggests that VE-cadherin controls claudin-5 expression by preventing the nuclear accumulation of FoxO1 and -catenin, which repress the claudin-5 promoter. This indicates that a crosstalk mechanism operates between these junctional structures

    Deposition of copper by plasma-enhanced atomic layer deposition using a novel N-Heterocyclic carbene precursor

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    Two novel N-heterocyclic carbene (NHC)-containing copper(I) amides are reported as atomic layer deposition (ALD) precursors. 1,3-Diisopropyl-imidazolin-2-ylidene copper hexamethyldisilazide (1) and 4,5-dimethyl-1,3-diisopropyl-imidazol-2-ylidene copper hexamethyldisilazide (2) were synthesized and structurally characterized. The thermal behavior of both compounds was studied by thermogravimetric analysis (TGA), and they were both found to be reasonably volatile compounds. Compound 1 had no residual mass in the TGA and showed long-term stability at temperatures as high as 130 °C, while 2 had a residual mass of 7.4%. Copper metal with good resistivity was deposited using 1 by plasma-enhanced atomic layer deposition. The precursor demonstrated self-limiting behavior indicative of ALD, and gave a growth rate of 0.2 Å/cycle. Compound 2 was unsuccessful as an ALD precursor under similar conditions. Density functional theory calculations showed that both compounds adsorb dissociatively onto a growing copper film as long as there is some atomic roughness, via cleavage of the Cu-carbene bond

    A multi-method approach for the integrative assessment of soil functions: Application on a coastal mountainous site of the Philippines

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    The projected increase of the world\u27s population and the sustainability challenges the agricultural sector is facing, call for the enhancement of multi-functionality in agriculture in order to simultaneously provide food while meeting environmental targets. Here, we use the Functional Land Management (FLM) framework to assess the supply of and the demand for soil functions to inform agri-environmental policy for Udalo, a mountainous site in the Philippines. As many emerging communities in developing nations, Udalo is on the cusp of rapid development due to the construction of a major road increasing its accessibility and attractiveness for land investment. We assessed the supply of four soil functions in relation to six land-use types and four slope categories. The function “productivity” was assessed by interviews with 128 farmers, “habitat for biodiversity” by a vegetation survey, and “soil conservation” and “water conservation” via a literature review. The demand for functions was first assessed from the “top-down” policy perspective via interviews and reviews of policy targets, then complemented by integrating the local “bottom-up” demands for functions. These were assessed by applying a Q methodology, providing insights in the prioritisation of functions from the perspective of 22 local actors. Maps of supply and demands were generated for each function: supply maps by overlaying land use and slope category, top-down demand maps from administrative zoning/land-use plans, and bottom-up demand maps from local actors designation of geomorphological areas. Our results revealed contrasting demands for functions, as well as a heterogeneous spatial distribution of supply and demands. Discrepancies emerged (i) between supply and demand, (ii) between bottom-up (local) demands and the top-down (policy driven) demand, and (iii) among local actors perspectives. Our study indicates that discrepancies are not necessarily conflicting, but can uncover pathways for defining compromises, representing attainable policy entry points. Not one single development model can meet the needs of every stakeholder; however, a combination of land uses and management strategies can meet divergent interests and allow for optimisation of functions. This integrative approach of FLM provides a socially embedded biophysical analysis and is a valuable tool for the design of customized land-use and agri-environmental policies

    Novel Escape Mutants Suggest an Extensive TRIM5α Binding Site Spanning the Entire Outer Surface of the Murine Leukemia Virus Capsid Protein

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    After entry into target cells, retroviruses encounter the host restriction factors such as Fv1 and TRIM5α. While it is clear that these factors target retrovirus capsid proteins (CA), recognition remains poorly defined in the absence of structural information. To better understand the binding interaction between TRIM5α and CA, we selected a panel of novel N-tropic murine leukaemia virus (N-MLV) escape mutants by a serial passage of replication competent N-MLV in rhesus macaque TRIM5α (rhTRIM5α)-positive cells using a small percentage of unrestricted cells to allow multiple rounds of virus replication. The newly identified mutations, many of which involve changes in charge, are distributed over the outer ‘top’ surface of N-MLV CA, including the N-terminal ÎČ-hairpin, and map up to 29 Ao apart. Biological characterisation with a number of restriction factors revealed that only one of the new mutations affects restriction by human TRIM5α, indicating significant differences in the binding interaction between N-MLV and the two TRIM5αs, whereas three of the mutations result in dual sensitivity to Fv1n and Fv1b. Structural studies of two mutants show that no major changes in the overall CA conformation are associated with escape from restriction. We conclude that interactions involving much, if not all, of the surface of CA are vital for TRIM5α binding
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