545 research outputs found

    Fuel Optimization in Multiple Diesel Driven Generator Power Plants

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    This paper presents two fuel optimization approaches for independent power producer (IPP) power plants consisting of multiple diesel driven generator sets (DGs). The optimization approaches utilize assumed information about the fuel consumption characteristics of each DG in an effort to demonstrate the potential benefits of acquiring such information. Reasonable variations in fuel consumption characteristics are based on measurements of a DG during restricted air filter flow operation. The two approaches are: (i) a gradient search approach capable of finding the optimal power generation for each DG in a fixed selection of DGs accommodating a given plant power reference and (ii) a genetic algorithm approach further capable of determining the optimal selection of DGs to operate in an IPP power plant. Both approaches show notable potential benefits, in terms of fuel savings, compared to current market-leading solutions

    WISH-R- a fast and efficient tool for construction of epistatic networks for complex traits and diseases

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    Abstract Background Genetic epistasis is an often-overlooked area in the study of the genomics of complex traits. Genome-wide association studies are a useful tool for revealing potential causal genetic variants, but in this context, epistasis is generally ignored. Data complexity and interpretation issues make it difficult to process and interpret epistasis. As the number of interaction grows exponentially with the number of variants, computational limitation is a bottleneck. Gene Network based strategies have been successful in integrating biological data and identifying relevant hub genes and pathways related to complex traits. In this study, epistatic interactions and network-based analysis are combined in the Weighted Interaction SNP hub (WISH) method and implemented in an efficient and easy to use R package. Results The WISH R package (WISH-R) was developed to calculate epistatic interactions on a genome-wide level based on genomic data. It is easy to use and install, and works on regular genomic data. The package filters data based on linkage disequilibrium and calculates epistatic interaction coefficients between SNP pairs based on a parallelized efficient linear model and generalized linear model implementations. Normalized epistatic coefficients are analyzed in a network framework, alleviating multiple testing issues and integrating biological signal to identify modules and pathways related to complex traits. Functions for visualizing results and testing runtimes are also provided. Conclusion The WISH-R package is an efficient implementation for analyzing genome-wide epistasis for complex diseases and traits. It includes methods and strategies for analyzing epistasis from initial data filtering until final data interpretation. WISH offers a new way to analyze genomic data by combining epistasis and network based analysis in one method and provides options for visualizations. This alleviates many of the existing hurdles in the analysis of genomic interactions

    Fuel Optimization in Multiple Diesel Driven Generator Power Plants

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    This paper presents two fuel optimization approaches for independent power producer (IPP) power plants consisting of multiple diesel driven generator sets (DGs). The optimization approaches utilize assumed information about the fuel consumption characteristics of each DG in an effort to demonstrate the potential benefits of acquiring such information. Reasonable variations in fuel consumption characteristics are based on measurements of a DG during restricted air filter flow operation. The two approaches are: (i) a gradient search approach capable of finding the optimal power generation for each DG in a fixed selection of DGs accommodating a given plant power reference and (ii) a genetic algorithm approach further capable of determining the optimal selection of DGs to operate in an IPP power plant. Both approaches show notable potential benefits, in terms of fuel savings, compared to current market-leading solutions

    The Maximum Significant Wave Height in the Southern North Sea

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    Development of a harmonised soil profile analytical database for Europe:a resource for supporting regional soil management

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    Soil mapping is an essential method for obtaining a spatial overview of soil resources that are increasingly threatened by environmental change and population pressure. Despite recent advances in digital soil-mapping techniques based on inference, such methods are still immature for large-scale soil mapping. During the 1970s, 1980s and 1990s, soil scientists constructed a harmonised soil map of Europe (1:1 000 000) based on national soil maps. Despite this extraordinary regional overview of the spatial distribution of European soil types, crude assumptions about soil properties were necessary for translating the maps into thematic information relevant to management. To support modellers with analytical data connected to the soil map, the European Soil Bureau Network (ESBW) commissioned the development of the soil profile analytical database for Europe (SPADE) in the late 1980s. This database contains soil analytical data based on a standardised set of soil analytical methods across the European countries. Here, we review the principles adopted for developing the SPADE database during the past five decades, the work towards fulfilling the milestones of full geographic coverage for dominant soils in all the European countries (SPADE level 1) and the addition of secondary soil types (SPADE level 2). We illustrate the application of the database by showing the distribution of the root zone capacity and by estimating the soil organic carbon (SOC) stocks at a depth of 1 m for Europe to be 60Ă—1015 g. The increased accuracy, potentially obtained by including secondary soil types (level 2), is shown in a case study to estimate SOC stocks in Denmark. Until data from systematic cross-European soil-sampling programmes have sufficient spatial coverage for reliable data interpolation, integrating national soil maps and locally assessed analytical data into a harmonised database remains a powerful resource to support soil resources management at regional and continental scales by providing a platform to guide sustainable soil management and food production

    Model for a Universe described by a non-minimally coupled scalar field and interacting dark matter

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    In this work it is investigated the evolution of a Universe where a scalar field, non-minimally coupled to space-time curvature, plays the role of quintessence and drives the Universe to a present accelerated expansion. A non-relativistic dark matter constituent that interacts directly with dark energy is also considered, where the dark matter particle mass is assumed to be proportional to the value of the scalar field. Two models for dark matter pressure are considered: the usual one, pressureless, and another that comes from a thermodynamic theory and relates the pressure with the coupling between the scalar field and the curvature scalar. Although the model has a strong dependence on the initial conditions, it is shown that the mixture consisted of dark components plus baryonic matter and radiation can reproduce the expected red-shift behavior of the deceleration parameter, density parameters and luminosity distance.Comment: 11 pages and 6 figures. To appear in GR

    Performance of a Spectral Wind-Wave Model in Shallow Water

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    On Higher Order Gravities, Their Analogy to GR, and Dimensional Dependent Version of Duff's Trace Anomaly Relation

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    An almost brief, though lengthy, review introduction about the long history of higher order gravities and their applications, as employed in the literature, is provided. We review the analogous procedure between higher order gravities and GR, as described in our previous works, in order to highlight its important achievements. Amongst which are presentation of an easy classification of higher order Lagrangians and its employment as a \emph{criteria} in order to distinguish correct metric theories of gravity. For example, it does not permit the inclusion of only one of the second order Lagrangians in \emph{isolation}. But, it does allow the inclusion of the cosmological term. We also discuss on the compatibility of our procedure and the Mach idea. We derive a dimensional dependent version of Duff's trace anomaly relation, which in \emph{four}-dimension is the same as the usual Duff relation. The Lanczos Lagrangian satisfies this new constraint in \emph{any} dimension. The square of the Weyl tensor identically satisfies it independent of dimension, however, this Lagrangian satisfies the previous relation only in three and four dimensions.Comment: 30 pages, added reference

    Friedmann Equation and Stability of Inflationary Higher Derivative Gravity

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    Stability analysis on the De Sitter universe in pure gravity theory is known to be useful in many aspects. We first show how to complete the proof of an earlier argument based on a redundant field equation. It is shown further that the stability condition applies to k≠0k \ne 0 Friedmann-Robertson-Walker spaces based on the non-redundant Friedmann equation derived from a simple effective Lagrangian. We show how to derive this expression for the Friedmann equation of pure gravity theory. This expression is also generalized to include scalar field interactions.Comment: Revtex, 6 pages, Add two more references, some typos correcte
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