336,230 research outputs found

    Influence of different soil preparation techniques on organically grown strawberries

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    From June 2005 till June 2007 different soil preparation techniques like chiselling and advance sowing of medicinal plants and green manuring were proofed for their influence on reducing plant losses of strawberries caused by root diseases like Phytophthora species and Verticillium dahliae. The variants were combined with potted plants and Frigos. The experiment took place on an organic fruit farm near Stuttgart, Germany, with the strawberry variety ´Elsanta´. Focused on root diseases, habit and yield chiselling combined with Frigos and green manuring combined with potted plants showed the best results. Generally the marketable yield was often below yields from conventional cultivation. This project is granted by Bundesprogramm Ökologischer Landbau (BÖL, FKZ 03OE087: 2004-2006, FKZ 06OE221: 2007-2009). It includes also experiments about cutting techniques at raspberries, plant protection at black- and gooseberries and weed control at blueberries and black currants. The part of weed control is carried out by ÖON Jork (Germany)

    Policy rationales for electronic information systems : an area of ambiguity

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    Child welfare and protection (CWP) has engaged in the introduction of Electronic Information Systems (EIS), such as electronic recording, assessment and decision- making tools. It has been argued that EIS have adverse consequences in which gov- ernments are conceived as homogeneous entities that install EIS for self-interested purposes. Consequently, research focuses on how social workers evade/reshape the sometimes pernicious effects of EIS. Insufficient attention has been given to the gov- ernmental perspective and to why governments install EIS. In this article, we contrib- ute to this debate by performing semi-structured interviews with policy actors (directors, policy advisers and staff members) in the field of CWP in Flanders. Asked about their rationales for installing EIS, they spoke of administrative, policy, care and economic reasons. However, while advocating these EIS, they also expressed a critical attitude concerning the usefulness of EIS, hoping that practitioners would move back and forth between governmental demands and day-to-day realities, to establish a more responsive social work. This ambiguous situation in which policy makers seem to be both strong supporters and critics of EIS at the same time is captivating, since it seems no longer necessary to perceive governments as a homogeneous bogeyman and social work as a victim

    A comparative analysis of executive information systems in organisations in South Africa and Spain

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    Executive Information Systems (EIS) grew out of the information needs of executives and are designed to serve the needs of users in strategic planning and decision-making. EIS are high risk information technology (IT) implementation projects. With the emergence of global information technologies, existing paradigms are being altered which are spawning new considerations for IT implementation. Web-based technologies are causing a revisit to existing IT implementation models, including those for EIS. The authors compare two recent survey studies of EIS implementation in well-established organisations in South Africa and Spain. From a comparative analysis, the authors report six identified similarities and three differences in EIS in these countries

    Particle Efficient Importance Sampling

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    The efficient importance sampling (EIS) method is a general principle for the numerical evaluation of high-dimensional integrals that uses the sequential structure of target integrands to build variance minimising importance samplers. Despite a number of successful applications in high dimensions, it is well known that importance sampling strategies are subject to an exponential growth in variance as the dimension of the integration increases. We solve this problem by recognising that the EIS framework has an offline sequential Monte Carlo interpretation. The particle EIS method is based on non-standard resampling weights that take into account the look-ahead construction of the importance sampler. We apply the method for a range of univariate and bivariate stochastic volatility specifications. We also develop a new application of the EIS approach to state space models with Student's t state innovations. Our results show that the particle EIS method strongly outperforms both the standard EIS method and particle filters for likelihood evaluation in high dimensions. Moreover, the ratio between the variances of the particle EIS and particle filter methods remains stable as the time series dimension increases. We illustrate the efficiency of the method for Bayesian inference using the particle marginal Metropolis-Hastings and importance sampling squared algorithms

    Underflight calibration of SOHO/CDS and Hinode/EIS with EUNIS-07

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    Flights of Goddard Space Flight Center's Extreme-Ultraviolet Normal-Incidence Spectrograph (EUNIS) sounding rocket in 2006 and 2007 provided updated radiometric calibrations for SOHO/CDS and Hinode/EIS. EUNIS carried two independent imaging spectrographs covering wavebands of 300-370 A in first order and 170-205 A in second order. After each flight, end-to-end radiometric calibrations of the rocket payload were carried out in the same facility used for pre-launch calibrations of CDS and EIS. During the 2007 flight, EUNIS, SOHO CDS and Hinode EIS observed the same solar locations, allowing the EUNIS calibrations to be directly applied to both CDS and EIS. The measured CDS NIS 1 line intensities calibrated with the standard (version 4) responsivities with the standard long-term corrections are found to be too low by a factor of 1.5 due to the decrease in responsivity. The EIS calibration update is performed in two ways. One is using the direct calibration transfer of the calibrated EUNIS-07 short wavelength (SW) channel. The other is using the insensitive line pairs, in which one member was observed by EUNIS-07 long wavelength (LW) channel and the other by EIS in either LW or SW waveband. Measurements from both methods are in good agreement, and confirm (within the measurement uncertainties) the EIS responsivity measured directly before the instrument's launch. The measurements also suggest that the EIS responsivity decreased by a factor of about 1.2 after the first year of operation. The shape of the EIS SW response curve obtained by EUNIS-07 is consistent with the one measured in laboratory prior to launch. The absolute value of the quiet-Sun He II 304 A intensity measured by EUNIS-07 is consistent with the radiance measured by CDS NIS in quiet regions near the disk center and the solar minimum irradiance obtained by CDS NIS and SDO/EVE recently.Comment: 16 pages, 14 figures, 5 tables, accepted by ApJ Supplement (Sep. 2011

    On Modeling and Analyzing Cost Factors in Information Systems Engineering

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    Introducing enterprise information systems (EIS) is usually associated with high costs. It is therefore crucial to understand those factors that determine or influence these costs. Though software cost estimation has received considerable attention during the last decades, it is difficult to apply existing approaches to EIS. This difficulty particularly stems from the inability of these methods to deal with the dynamic interactions of the many technological, organizational and projectdriven cost factors which specifically arise in the context of EIS. Picking up this problem, we introduce the EcoPOST framework to investigate the complex cost structures of EIS engineering projects through qualitative cost evaluation models. This paper extends previously described concepts and introduces design rules and guidelines for cost evaluation models in order to enhance the development of meaningful and useful EcoPOST cost evaluation models. A case study illustrates the benefits of our approach. Most important, our EcoPOST framework is an important tool supporting EIS engineers in gaining a better understanding of the critical factors determining the costs of EIS engineering projects

    Environmental and Regional Problems of Contaminated Sites

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    Environmental Economics and Policy, Land Economics/Use,

    Parallel Evolution of Quasi-separatrix Layers and Active Region Upflows

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    Persistent plasma upflows were observed with Hinode's EUV Imaging Spectrometer (EIS) at the edges of active region (AR) 10978 as it crossed the solar disk. We analyze the evolution of the photospheric magnetic and velocity fields of the AR, model its coronal magnetic field, and compute the location of magnetic null-points and quasi-sepratrix layers (QSLs) searching for the origin of EIS upflows. Magnetic reconnection at the computed null points cannot explain all of the observed EIS upflow regions. However, EIS upflows and QSLs are found to evolve in parallel, both temporarily and spatially. Sections of two sets of QSLs, called outer and inner, are found associated to EIS upflow streams having different characteristics. The reconnection process in the outer QSLs is forced by a large-scale photospheric flow pattern which is present in the AR for several days. We propose a scenario in which upflows are observed provided a large enough asymmetry in plasma pressure exists between the pre-reconnection loops and for as long as a photospheric forcing is at work. A similar mechanism operates in the inner QSLs, in this case, it is forced by the emergence and evolution of the bipoles between the two main AR polarities. Our findings provide strong support to the results from previous individual case studies investigating the role of magnetic reconnection at QSLs as the origin of the upflowing plasma. Furthermore, we propose that persistent reconnection along QSLs does not only drive the EIS upflows, but it is also responsible for a continuous metric radio noise-storm observed in AR 10978 along its disk transit by the Nan\c{c}ay Radio Heliograph.Comment: 29 pages, 10 figure
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