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Supplier selection is a complex task which assumes decision making in presence of many conflicting criteria and various parameters. If there are more than one decision maker, the problem shifts into a group context and it requires proper approach in mediating the decision making process and use of supporting multi-criteria methods and tools. This paper proposes group decision making approach for supplier selection based on analytic hierarchy process (AHP) that is combined with consensus convergence model, and two voting methods, non-preferential approval voting and preferential Borda count. Proposed approach utilized strengths of these methods thus enabling their adaption to the specific decision problem of supplier selection. An example of selecting a supplier of irrigation equipment in the company engaged in projecting, installing and maintenance of irrigation systems is used to explain and demonstrate how proposed approach can be implemented. Furthermore, this approach is viable as sufficiently general in supporting different selection processes in a field of water planning, management, and development and it can be adapted and applied on various group decision making problems. 相似文献
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Summary The three-dimensional cloud-resolving mesoscale model is used to simulate an individual Cb cloud in condition of real orography. We have conducted our numerical experiments over an area known as hail bearing clouds source. Once formed such clouds regenerate and propagate along the valley if the shallow layer of strong wind shear exists. The orographic effects on model Cb cloud are recognized through comparison of simulated cloud characteristics with those calculated for the flat terrain. Sensitivity experiments with respect to the wind shear layer depth are also conducted.Our results demonstrate the model capability to simulate well some observational Cb cloud characteristics. It is shown that the river valley is of essential importance for Cb cloud development. The most prominent features of the model cloud in this case are as follows: fast propagation along the river valley; considerable depth of the cold air nose with pronounced pulsation mechanism and intense cell regeneration at the leading edge of cold air outflow. Model and observed radar reflectivities in the vertical cross-section are in agreement. Some characteristics of surface cumulative rain precipitation are also well reproduced by the model. In contrast with the real orography case, the model cloud is more intense and it propagates freely in lateral direction for the flat terrain. The cell regeneration associated with forced updraft above the cold air nose is not pronounced in contrast with earlier considerations. Reflectivity pattern near the ground, having mainly bat-like wings, encircles much larger area with altitude compared to the case of real orography. Finally, the model cloud characteristics depend strongly on shear layer.Received June 2002; revised August 22, 2002; accepted October 1, 2002
Published online: April 10, 2003 相似文献
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Global changes in the marine environment and the continuing disposal of genotoxic xenobiotics are increasing the importance of environmental pollution monitoring and of biomonitoring programs. Current approaches focus on investigations at regional and local levels in an attempt to precisely define the nature and extent of any potential environmental crisis. We have initiated, for the first time, a long-term biomonitoring program focusing on the Croatian coast of the Adriatic Sea to contribute to a more detailed understanding of marine genotoxic effects using the mussels Mytilus galloprovincialis Lam., collected along the eastern Adriatic coast over a period of five years (1998-2002), as a key test organism. The integrity of DNA in its gill homogenate was examined by the Fast Micromethod. The strand scission factor (SSF) values, as a measure of DNA integrity, DNA damage or incomplete repair have been used for the ranking of sampling sites with respect to significant genotoxic stress due to the influence or effects of genotoxic xenobiotics. The region of Split (Kastela Bay) proved to be the area with the heaviest load of genotoxic agents. The investigation of harmful effects in the ecosystem based on biomonitoring of genetic and other agents, not only on local levels but also on a wider scale, is considered as an important step in marine environmental management. 相似文献
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Boštjan Podkrajšek Gorazd Berčič Janja Turšič Irena Grgić 《Journal of Atmospheric Chemistry》2004,47(3):287-303
The reaction kinetics of S(IV) autoxidation catalyzed by Mn(II) in the pH range 3–5 typical for atmospheric liquid water,
was investigated. For reactions with pH maintained constant during the reaction course, the predictions obtained by a simple
integral approach cover kinetic results only for concentrations of HSO
3
−
up to 0.2 mM at pH 4.5. Thus, a generalized simple kinetic model, which can be used for predicting the reaction kinetics
in wider concentration, pH and temperature ranges, was derived. This model is based on the assumption that the reaction rate
is proportional to the concentration of a transient manganese-sulfito complex formed in the initial step of a radical chain
mechanism. In the proposed power law rate equation
the concentration of complex is calculated from the stability constant K and concentrations of reactants at a specific reaction time. This rate equation adequately predicts the reaction kinetics
in the pH range 3–5, in the concentration ranges 0.1 ≤ [HSO
3
−
] ≤ 0.4 mM and 2 ≤ [Mn(II)] ≤ 14.6 μM. For the temperature range 15–35 °C, the estimated value for activation energy is 92.0
± 0.1 kJ mol−1 and the Gibbs free energy of formation of the manganese-sulfito complex is −20.4 ± 0.3 kJ mol−1. Furthermore, the kinetics for catalytic reactions with pH maintained constant during the reaction course as well as with
initial pH adjusted only at the start of the reaction, is described satisfactorily by the present model. 相似文献