The Astro-WISE optical image pipeline     

John P. McFarland  Gijs Verdoes-Kleijn  Gert Sikkema  Ewout M. Helmich  Danny R. Boxhoorn  Edwin A. Valentijn 《Experimental Astronomy》2013,35(1-2):45-78

We have designed and implemented a novel way to process wide-field astronomical data within a distributed environment of hardware resources and humanpower. The system is characterized by integration of archiving, calibration, and post-calibration analysis of data from raw, through intermediate, to final data products. It is a true integration thanks to complete linking of data lineage from the final catalogs back to the raw data. This paper describes the pipeline processing of optical wide-field astronomical data from the WFI (http://www.eso.org/lasilla/instruments/wfi/) and OmegaCAM (http://www.astro-wise.org/~omegacam/) instruments using the Astro-WISE information system (the Astro-WISE Environment or simply AWE). This information system is an environment of hardware resources and humanpower distributed over Europe. AWE is characterized by integration of archiving, data calibration, post-calibration analysis, and archiving of raw, intermediate, and final data products. The true integration enables a complete data processing cycle from the raw data up to the publication of science-ready catalogs. The advantages of this system for very large datasets are in the areas of: survey operations management, quality control, calibration analyses, and massive processing.  相似文献   

Forest dynamics and the importance of place in western Honduras     

Danny Redo  J.O. Joby Bass  Andrew C. Millington 《Applied geography (Sevenoaks, England)》2009,29(1):91-110

Analyses of landscape change using remotely sensed satellite imagery constitute a large component of forest transition research, allowing for assessments of large areas. In the western highlands of Honduras is an area of complex forest dynamics (～45,000 ha) that has seen significant forest regeneration in recent years. However, analysis of the larger region (～500,000 ha) shows net forest loss. The comparative aspects highlight the importance of site selection and scale in forest transition analysis, a process often ignored in the land-use and land-cover change (LULCC) and forest transition literature. Results also highlight the importance of analyzing human-induced fragmentation at a variety of selected sites and a range of spatial scales, and producing quality, accurate forest cover and change maps.  相似文献   

Trace elements in tissues of cetacean species rarely stranded along the Israeli Mediterranean coast     

Efrat Shoham-Frider  Dan Kerem  Mia Roditi-Elasar  Oz Goffman  Danny Morick  Olga Yoffe  Nurit Kress 《Marine pollution bulletin》2014

In this paper we present the concentrations of Hg, Cd, Se, Pb, Cu, Mn, Zn and Fe in organs of 6 non-common specimens of cetaceans that were stranded along the Israeli Mediterranean coast (IMC), during 2002–2010: two fin whales, one minke whale, one Cuvier’s beaked whale, one rough-toothed dolphin, and one Risso’s dolphin. Most of the specimens were calves stranded by accident. Concentrations of Hg and Cd were low in tissues of the baleen whales and higher in the toothed whales, with maximum concentrations of 1067 mg kg⁻¹ Hg in the liver of the Risso’s dolphin and 29 mg kg⁻¹ Cd in the kidney of the Cuvier’s beaked whale. As far as we are aware, this is the first report of trace elements in baleen whales in the Eastern Mediterranean, and the first report of trace elements in minke whale and rough-toothed dolphin in the Mediterranean.  相似文献   

Changes in atmospheric circulation and the Arctic Oscillation preserved within a millennial length reconstruction of summer cloud cover from northern Fennoscandia   总被引：3，自引：3，他引：0  

Giles H. F. Young  Danny McCarroll  Neil J. Loader  Mary H. Gagen  Andreas J. Kirchhefer  Joanne C. Demmler 《Climate Dynamics》2012,39(1-2):495-507

Cloud cover currently represents the single greatest source of uncertainty in General Circulation Models. Stable carbon isotope ratios (δ¹³C) from tree-rings, in areas of low moisture stress, are likely to be primarily controlled by photosynthetically active radiation (PAR), and therefore should provide a proxy record for cloud cover or sunshine; indeed this association has previously been demonstrated experimentally for Scots pine in Fennoscandia, with sunlight explaining ca 90% of the variance in photosynthesis and temperature only ca 4%. We present a statistically verifiable 1011-year reconstruction of cloud cover from a well replicated, annually-resolved δ¹³C record from Forfjord in coastal northwestern Norway. This reconstruction exhibits considerable variability in cloud cover over the past millennium, including extended sunny periods during the cool seventeenth and eighteenth centuries and warm cloudy periods during the eleventh, early fifteenth and twentieth centuries. We find that while a generally positive relationship persists between sunshine and temperature at high-frequency, at lower (multi-decadal) frequencies the relationship is more often a negative one, with cool periods being sunny (most notably the Little Ice Age period from 1600 to 1750 CE) and warm periods more cloudy (e.g. the mediaeval and the twentieth century). We conclude that these long-term changes may be caused by changes in the dominant circulation mode, likely to be associated with the Arctic Oscillation. There is also strong circumstantial evidence that prolonged periods of high summer cloud cover, with low PAR and probably high precipitation, may be in part responsible for major European famines caused by crop failures.  相似文献   

Influence of Random Inclusion of Synthetic Wicks Fibers of Hair on the Behavior of Clayey Soils     

Armand Sylvain Ludovic Wouatong  Wamba Danny Love Djukem  François Ngapgue  Valentine Katte  Véronique Kamgang Kabeyene Beyala 《Geotechnical and Geological Engineering》2017,35(6):2637-2646

Several soil improvement methods are used to enhance the engineering properties of soil, among which, reinforcement by fibers is considered as an effective ground improvement method because of its cost effectiveness, and easy adaptability. The present investigation chooses synthetic wick and vinifera raphia fibers as reinforcement. The synthetic wick fiber was randomly included into the soil at four different percentages i.e. 0, 2, 4, 6% by volume of raw soil. Vinifera raphia fiber was used at one percentage (4%) as control. The main objective of this research is to focus on the strength behavior of clayey soil reinforced with randomly included synthetic wick fiber. The physical and mineralogical characterization was carried out on ten soil samples. The compression, flexion, abrasion, water absorption and capillarity tests were performed on synthetic wick reinforced specimens with various fiber contents. The results of these tests have clearly shown an improvement in the compression strength values from 1.65 to 2.84 MPa for the wicks fibers, and the flexural strength values which varied between 1.08 and 1.96 MPa. Hence, the waste of synthetic wick fibers is therefore an efficient reinforcement for compressed earth blocks, which are very significant for construction of durable and economic infrastructures.  相似文献   

Spectral filtering as a method of visualising and removing striped artefacts in digital elevation data     

Katherine Arrell  Steve Wise  Jo Wood  Danny Donoghue 《地球表面变化过程与地形》2008,33(6):943-961

Spectral filtering was compared with traditional mean spatial filters to assess their ability to identify and remove striped artefacts in digital elevation data. The techniques were applied to two datasets: a 100 m contour derived digital elevation model (DEM) of southern Norway and a 2 m LiDAR DSM of the Lake District, UK. Both datasets contained diagonal data artefacts that were found to propagate into subsequent terrain analysis. Spectral filtering used fast Fourier transformation (FFT) frequency data to identify these data artefacts in both datasets. These were removed from the data by applying a cut filter, prior to the inverse transform. Spectral filtering showed considerable advantages over mean spatial filters, when both the absolute and spatial distribution of elevation changes made were examined. Elevation changes from the spectral filtering were restricted to frequencies removed by the cut filter, were small in magnitude and consequently avoided any global smoothing. Spectral filtering was found to avoid the smoothing of kernel based data editing, and provided a more informative measure of data artefacts present in the FFT frequency domain. Artefacts were found to be heterogeneous through the surfaces, a result of their strong correlations with spatially autocorrelated variables: landcover and landsurface geometry. Spectral filtering performed better on the 100 m DEM, where signal and artefact were clearly distinguishable in the frequency data. Spectrally filtered digital elevation datasets were found to provide a superior and more precise representation of the landsurface and be a more appropriate dataset for any subsequent geomorphological applications. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

P. R. Van Gardingen, G. M. Foody, and P. J. Curran (eds.), Scaling-Up from Cell to Landscape     

L. D. Danny Harvey 《Climatic change》1999,42(2):485-487

  相似文献   

Urban reactions to the global warming issue: Agenda setting in Toronto and Chicago   总被引：1，自引：0，他引：1  

W. Henry Lambright  Stanley A. Chjangnon  L. D. Danny Harvey 《Climatic change》1996,34(3-4):463-478

Little research has been done about what cities could or should do concerning potential global warming. A few cities have adopted programs to deal with impacts they perceive may occur, and a worldwide network of 100 cities involved with CO₂ reduction has recently emerged. Global warming is a new issue for cities and most are only dimly aware of how it may affect them. Toronto, through the efforts of a few leaders, has become a pioneer in the development of an urban response program to global warming. It has charged a city agency to deal with global warming issues, in particular emissions reduction. Chicago is aware of the issue and is concerned about the negative impacts global warming could produce. While behind Toronto, Chicago is moving forward in a number of areas. These two cities illuminate the policy-making process for global warming at the urban level and the role {atpolicy entrepreneurs} can play at this level. In comparing the two cities, a common model of policy development is utilized.  相似文献   

A physical model for the simulation of bioturbation and its comparison to experiments with oligochaetes     

Sanat Mohanty  Danny D. Reible  K. T. Valsaraj  L. J. Thibodeaux 《Estuaries and Coasts》1998,21(2):255-262

  相似文献   

Alkoxyquinoline O-dealkylation: A new fluorimetric assay for hydrocarbon-induced cytochrome P450 in fish     

M. Danny Burke  Douglas Brown  Richard T. Mayer  Dominic F.J. Houlihan 《Marine environmental research》1995,39(1-4)

The O-dealkylation of a new series of substrates, the alkoxyquinolines, provides a new easy fluorimetric assay for measuring the induction of cytochrome P450 by polycyclic aromatic hydrocarbons and drilling mud oil in fish. Expression of the results as a ratio between the inducible butyloxyquinoline O-dealkylation (BuQOD) activity and the non-inducible benzyloxyquinoline O-dealkylation (BeQOD) activity (i.e. the ‘BuQOD:-BeQOD quotient’) maximises the degree of induction measured and minimises the degree of inter-animal variation.  相似文献