In the process of concept design of offshore platforms, it is necessary to select the best from feasible alternatives through comparison and filter. The criterion set, used to evaluate and select the satisfying altern...In the process of concept design of offshore platforms, it is necessary to select the best from feasible alternatives through comparison and filter. The criterion set, used to evaluate and select the satisfying alternative, consists of many qualitative and quantitative factors. Therefore, the selection is a problem of multicriteria and semi-structural decision-making. Different from traditional methods in semi-structural decision-making, a new framework and methodology is presented in this paper for evaluation of offshore platform alternatives. First, the criterion set is established for the evaluation of alternatives. Next, the approach is studied to construct the relative membership degree matrix, in which both qualitative and quantitative factors are consistent with the uniform calculating standard. And then a new weight-assessing method is developed for calculation of the weights based on the relative membership degree matrix.Finally, a multi-hierarchy fuzzy optimum model is adopted to select the satisfying offshore platform alternative. A case study shows that the new framework and methodology are scientific, reasonable and easy to use in practice.展开更多
A Three-Scale Fuzzy Analytical Hierarchy Process (T-FAHP) is proposed by introducing the Three-Scale Analyti-
cal Hierarchy Process (T-AHP) and the trapezoid fuzzy number. A multi-objective optimization model based on...A Three-Scale Fuzzy Analytical Hierarchy Process (T-FAHP) is proposed by introducing the Three-Scale Analyti-
cal Hierarchy Process (T-AHP) and the trapezoid fuzzy number. A multi-objective optimization model based on the
T-FAHP is presented subsequently, in which many factors influencing the lectotype of offshore platform are taken intoaccount synthetically, such as the original investment, the maintenance cost, the ability of resisting fatigue and corrosion,the construction period, the threat to the environment, and so on. With this method, the experts can give the relatively precise ranking weight of each index and at the same time the requirement of consistence checking can be met. The result
of a calculation example shows that the T-FAHP is practical.展开更多
Three new species are described and another is recognized in Campyloneurum. Two species occur in Mexico to El Salvador and the others two are present in Nicaragua, Costa Rica and Panama. The new species are Campyloneu...Three new species are described and another is recognized in Campyloneurum. Two species occur in Mexico to El Salvador and the others two are present in Nicaragua, Costa Rica and Panama. The new species are Campyloneurum acutum A. Rojas, C. leoniae A. Rojas and C. madrense A. Rojas. The first species differs from C. xalapense by broader rhizome scales, acute to attenuate blade apex, commonly two series of areoles between parallel veins, commonly one sori per areole and hydathodes absent or few evident. Campyloneurum leoniae differs from C. irregulare by more compact and non-pruinose rhizomes, thinner stipes, relatively broader, thinner and more opaque laminae, and distribution at lower elevations. Campyloneurum madrense is different to C. angustifolium because it has narrower and darker rhizome scales with denticulate margin, long scales cells and distributed at lower elevations. Finally, Campylonerum pittieri is here recognized as valid species and it differs from the similar C. amphostenon by longer rhizomes with appressed scales that have a patent, long acuminate apices, relative broader laminae, veins evident and distribution at higher elevations.展开更多
基金The work was financially supported by the National Natural Science Foundation of China (Grant No. 59179376)
文摘In the process of concept design of offshore platforms, it is necessary to select the best from feasible alternatives through comparison and filter. The criterion set, used to evaluate and select the satisfying alternative, consists of many qualitative and quantitative factors. Therefore, the selection is a problem of multicriteria and semi-structural decision-making. Different from traditional methods in semi-structural decision-making, a new framework and methodology is presented in this paper for evaluation of offshore platform alternatives. First, the criterion set is established for the evaluation of alternatives. Next, the approach is studied to construct the relative membership degree matrix, in which both qualitative and quantitative factors are consistent with the uniform calculating standard. And then a new weight-assessing method is developed for calculation of the weights based on the relative membership degree matrix.Finally, a multi-hierarchy fuzzy optimum model is adopted to select the satisfying offshore platform alternative. A case study shows that the new framework and methodology are scientific, reasonable and easy to use in practice.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.59895410)
文摘A Three-Scale Fuzzy Analytical Hierarchy Process (T-FAHP) is proposed by introducing the Three-Scale Analyti-
cal Hierarchy Process (T-AHP) and the trapezoid fuzzy number. A multi-objective optimization model based on the
T-FAHP is presented subsequently, in which many factors influencing the lectotype of offshore platform are taken intoaccount synthetically, such as the original investment, the maintenance cost, the ability of resisting fatigue and corrosion,the construction period, the threat to the environment, and so on. With this method, the experts can give the relatively precise ranking weight of each index and at the same time the requirement of consistence checking can be met. The result
of a calculation example shows that the T-FAHP is practical.
文摘Three new species are described and another is recognized in Campyloneurum. Two species occur in Mexico to El Salvador and the others two are present in Nicaragua, Costa Rica and Panama. The new species are Campyloneurum acutum A. Rojas, C. leoniae A. Rojas and C. madrense A. Rojas. The first species differs from C. xalapense by broader rhizome scales, acute to attenuate blade apex, commonly two series of areoles between parallel veins, commonly one sori per areole and hydathodes absent or few evident. Campyloneurum leoniae differs from C. irregulare by more compact and non-pruinose rhizomes, thinner stipes, relatively broader, thinner and more opaque laminae, and distribution at lower elevations. Campyloneurum madrense is different to C. angustifolium because it has narrower and darker rhizome scales with denticulate margin, long scales cells and distributed at lower elevations. Finally, Campylonerum pittieri is here recognized as valid species and it differs from the similar C. amphostenon by longer rhizomes with appressed scales that have a patent, long acuminate apices, relative broader laminae, veins evident and distribution at higher elevations.
