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991.
Dobrila Petrovic Ying Xie Keith Burnham Radivoj Petrovic 《European Journal of Operational Research》2008
This paper considers a single product inventory control in a Distribution Supply Chain (DSC). The DSC operates in the presence of uncertainty in customer demands. The demands are described by imprecise linguistic expressions that are modelled by discrete fuzzy sets. Inventories at each facility within the DSC are replenished by applying periodic review policies with optimal order up-to-quantities. Fuzzy customer demands imply fuzziness in inventory positions at the end of review intervals and in incurred relevant costs per unit time interval. The determination of the minimum of defuzzified total cost of the DSC is a complex problem which is solved by applying decomposition; the original problem is decomposed into a number of simpler independent optimisation subproblems, where each retailer and the warehouse determine their optimum periodic reviews and order up-to-quantities. An iterative coordination mechanism is proposed for changing the review periods and order up-to-quantities for each retailer and the warehouse in such a way that all parties within the DSC are satisfied with respect to total incurred costs per unit time interval. Coordination is performed by introducing fuzzy constraints on review periods and fuzzy tolerances on retailers and warehouse costs in local optimisation subproblems. 相似文献
992.
本文介绍空腔靶设计的物理思想、及能量吸收特性、X光转换特性和堵腔特性的实验研究方法,给出了实验观察到的一系列物理现象,通过对现象的分析而得出空腔靶的能量吸收和X光转换明显优于平面靶;利用相对孔径较大的聚焦透镜打空腔靶有利于改善靶的能量吸收和转换特性的结论。 相似文献
993.
994.
995.
An HPLC method with polarographic detection for the trace determination of artemether in plasma and whole blood was developed and applied to pharmacokinetic and clinical pharmacological studies. The method showed high sensitivity and selectivity because of the easy reduction of the peroxide linkage of artemether at the mercury drop electrode. The detection limit was 10 ng and the detector response was linear over the range of 10 ng to 1 microgram artemether injected onto the column. The largest relative standard deviation of 10 replicate measurements of standard solutions (concentrations of 10 ng/mL-1 microgram/mL) was 8%. The recovery from whole blood and plasma of added drug (concentrations of 15-480 ng/mL) was 71-100%. 相似文献
996.
997.
The template-directed fabrication of highly-ordered porous film is of significant importance in implementation of the photonic band gap structure. The paper reports a simple and effective method to improve the electrodeposition of metal porous film by utilizing highly-ordered polystyrene spheres (PSs) template. By surface-modification method, the hydrophobic property of the PSs template surfaces was changed into hydrophilic one. It was demonstrated that the surface modification process enhanced the permeability of the electrolyte solution in the nanometer-sized voids of the colloidal template. The homogeneously deposited copper film with the highly-ordered voids in size of less than 500 nm was successfully obtained. In addition, it was found that large defects, such as microcracks in the template, strongly influenced the macroporous films quality. An obvious preferential growth in the cracked area was observed. 相似文献
998.
This paper is concerned with coupled linear forward-backward stochastic differential equations(FBSDEs, for short). When the homogeneous coefficients are deterministic(the non-homogeneous coefficients can be random), we obtain an Lp-result(p > 2), including the existence and uniqueness of the p-th power integrable solution, a p-th power estimate, and a related continuous dependence property of the solution on the coefficients, for coupled linear FBSDEs in the monotonicity framework ... 相似文献
999.
Xiangdong Xie 《Mathematische Zeitschrift》2008,259(2):249-253
We establish a Bowen type rigidity theorem for the fundamental group of a noncompact hyperbolic manifold of finite volume
(with dimension at least 3).
相似文献
1000.
Photoionization Detector for Portable Rapid GC 总被引:1,自引:0,他引:1
With the development of portable rapid gas chromatography (GC) for environmental monitoring the photoionization detector (PID)
has potential application. The frequent calibration required and the relatively large dead volume have limited the use of
the PID, however. An improved PID which resolves these problems is proposed in this paper. Compared with a commercial instrument,
signal generation, the main aspect of the improved PID, has also been optimized. In the improved PID the sample is directed
to flow across the lamp window, rather than toward the lamp, and a new, simple automatic self-cleaning technique, which effectively
eliminates contaminants and substantially reduces drift, has also been adopted. Use of new electrodes has effectively reduced
the background noise and dead volume of the PID. As a result of this new design the PID should be more compatible with rapid
portable GC in environmental monitoring, because of elimination of most of the tedious cleaning and calibration previously
necessary. 相似文献