1,994 research outputs found

    An integrated decision support environment for organisational decision making

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    Traditional decision support systems are based on the paradigm of a single decision maker working at a stand-alone computer or terminal who has a specific decision to make with a specific goal in mind. Organisational decision support systems aim to support decision makers at all levels of an organisation (from executive, middle management managers to operators), who have a variety of decisions to make, with different priorities, often in a distributed environment. Such systems are designed and developed with extra functionality to meet the challenge. This paper proposes an Integrated Decision Support Environment (IDSE) for organisational decision making. The IDSE is designed and developed based on distributed client/server networking, with a combination of tight and loose integration approaches for information exchange and communication. The prototype of the IDSE demonstrates a good balance between flexibility and reliability

    Knowledge re-use for decision support

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    Effective decision support has already been identified as a fundamental requirement for the realisation of Network Enabled Capability. Decision making itself is a knowledge-intensive process, and it is known that right decisions can only be reached based on decision maker's good judgement, which in turn is based on sufficient knowledge. It is not unusual for decision makers to make incorrect decisions because of insufficient knowledge. However, it is not always possible for decision makers to have all the knowledge needed for making decisions in complex situations without external support. The re-use of knowledge has been identified as providing an important contribution to such support, and this paper considers one, hitherto unexplored, aspect of how this may be achieved. This paper is concerned with the computational view of knowledge re-use to establish an understanding of a knowledge-based system for decision support. The paper explores knowledge re-use for decision support from two perspectives: knowledge provider's and knowledge re-user's. Key issues and challenges of knowledge re-use are identified from both perspectives. A structural model for knowledge re-use is proposed with initial evaluation through empirical study of both experienced and novice decision maker's behaviour in reusing knowledge to make decisions. The proposed structural model for knowledge re-use captures five main elements (knowledge re-uers, knowledge types, knowledge sources, environment, and integration strategies) as well as the relationships between the elements, which forms a foundation for constructing a knowledge-based decision support system. The paper suggests that further research should be investigating the relationship between knowledge re-use and learning to achieve intelligent decision support

    Effective Dynamic Range in Measurements with Flash Analog-to-Digital Convertor

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    Flash Analog to Digital Convertor (FADC) is frequently used in nuclear and particle physics experiments, often as the major component in big multi-channel systems. The large data volume makes the optimization of operating parameters necessary. This article reports a study of a method to extend the dynamic range of an 8-bit FADC from the nominal 28\rm{2^8} value. By comparing the integrated pulse area with that of a reference profile, good energy reconstruction and event identification can be achieved on saturated events from CsI(Tl) crystal scintillators. The effective dynamic range can be extended by at least 4 more bits. The algorithm is generic and is expected to be applicable to other detector systems with FADC readout.Comment: 19 pages, 1 table, 10 figure

    The impact of resources on decision making

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    Decision making is a significant activity within industry and although much attention has been paid to the manner in which goals impact on how decision making is executed, there has been less focus on the impact decision making resources can have. This article describes an experiment that sought to provide greater insight into the impact that resources can have on how decision making is executed. Investigated variables included the experience levels of decision makers and the quality and availability of information resources. The experiment provided insights into the variety of impacts that resources can have upon decision making, manifested through the evolution of the approaches, methods, and processes used within it. The findings illustrated that there could be an impact on the decision-making process but not on the method or approach, the method and process but not the approach, or the approach, method, and process. In addition, resources were observed to have multiple impacts, which can emerge in different timescales. Given these findings, research is suggested into the development of resource-impact models that would describe the relationships existing between the decision-making activity and resources, together with the development of techniques for reasoning using these models. This would enhance the development of systems that could offer improved levels of decision support through managing the impact of resources on decision making

    Low-dimensional long-range topological structure in the QCD vacuum

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    Lattice topological charge associated with Ginsparg-Wilson fermions exhibits generic topological stability over quantum ensemble of configurations contributing to the QCD path integral. Moreover, the underlying chiral symmetry leads to the suppression of ultraviolet noise in the associated topological charge densities ("chiral smoothing"). This provides a solid foundation for the direct study of the role of topological charge fluctuations in the physics of QCD vacuum. Using these tools it was recently demonstrated that: (a) there is a well-defined space-time structure (order) in topological charge density (defined through overlap fermions) for typical configurations contributing to QCD path integral; (b) this fundamental structure is low-dimensional, exhibiting sign-coherent behavior on subsets of dimension less than four and not less than one; (c) the structure has a long-range global character (spreading over maximal space-time distances) and is built around the locally one-dimensional network of strong fields (skeleton). In this talk we elaborate on certain aspects and implications of these results.Comment: 3 pages, 1 figure; Lattice2003(topology

    SU(3) lattice gauge theory with a mixed fundamental and adjoint plaquette action: Lattice artefacts

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    We study the four-dimensional SU(3) gauge model with a fundamental and an adjoint plaquette term in the action. We investigate whether corrections to scaling can be reduced by using a negative value of the adjoint coupling. To this end, we have studied the finite temperature phase transition, the static potential and the mass of the 0^{++} glueball. In order to compute these quantities we have implemented variance reduced estimators that have been proposed recently. Corrections to scaling are analysed in dimensionless combinations such as T_c/\sqrt{\sigma} and m_{0^{++}}/T_c. We find that indeed the lattice artefacts in e.g. m_{0^{++}}/T_c can be reduced considerably compared with the pure Wilson (fundamental) gauge action at the same lattice spacing.Comment: 36 pages, 12 figure

    High Spin Glueballs from the Lattice

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    We discuss the principles underlying higher spin glueball calculations on the lattice. For that purpose, we develop numerical techniques to rotate Wilson loops by arbitrary angles in lattice gauge theories close to the continuum. As a first application, we compute the glueball spectrum of the SU(2) gauge theory in 2+1 dimensions for both parities and for spins ranging from 0 up to 4 inclusive. We measure glueball angular wave functions directly, decomposing them in Fourier modes and extrapolating the Fourier coefficients to the continuum. This allows a reliable labelling of the continuum states and gives insight into the way rotation symmetry is recovered. As one of our results, we demonstrate that the D=2+1 SU(2) glueball conventionally labelled as J^P = 0^- is in fact 4^- and that the lightest ``J=1'' state has, in fact, spin 3.Comment: Minor changes in the text; the spin 4 glueball mass is taken further out in Euclidean time at higher beta values. 41 pages, 20 figure

    Spaceborne SAR attitude steering method for smart imaging mode

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    The current spaceborne synthetic aperture radar systems are operated to illuminate the scene along the satellite flying direction. However, in many cases, the interested areas are not parallel to the flying direction, so an innovative smart imaging mode is acquired, which can be employed for illuminating scene along a given direction. A novel three-axis attitude steering method is proposed for smart imaging mode. First, mathematical model of the attitude steering is built by considering the restrictive conditions of zero-Doppler centroid requirement and the position of interested area. Then, an iterative optimisation algorithm is designed to calculate the three-axis steering angles. Finally, experiment results using the satellite tool kit tool validate the proposed methods well, especially in the case of coastline imaging

    Search for Oscillation of the Electron-Capture Decay Probability of 142^{142}Pm

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    We have searched for time modulation of the electron capture decay probability of 142^{142}Pm in an attempt to confirm a recent claim from a group at the Gesellschaft f\"{u}r Schwerionenforschung (GSI). We produced 142^{142}Pm via the 124^{124}Sn(23^{23}Na, 5n)142^{142}Pm reaction at the Berkeley 88-Inch Cyclotron with a bombardment time short compared to the reported modulation period. Isotope selection by the Berkeley Gas-filled Separator is followed by implantation and a long period of monitoring the 142^{142}Nd Kα_{\alpha} x-rays from the daughter. The decay time spectrum of the x-rays is well-described by a simple exponential and the measured half-life of 40.68(53) seconds is consistent with the accepted value. We observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by Litvinov {\it et al.} (Phys. Lett. B 664 (2008) 162; arXiv:0801.2079 [nucl-ex]). A literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in 142^{142}Eu electron-capture decay. A reanalysis of the published data shows no oscillatory behavior.Comment: 12 pages (double-spaced), 6 figure
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