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21.
Ample fields play an important role in possibility theory. These fields of subsets of a universe, which are additionally closed under arbitrary unions, act as the natural domains for possibility measures. A set provided with an ample field is then called an ample space. In this paper we generalise Wang's notions of product ample field and product ample space. We make a topological study of ample spaces and their products, and introduce ample subspaces, extensions and one-point extensions of ample spaces. In this way, a first step towards a mathematical theory of possibilistic processes is made. 相似文献
22.
1IntroductionLetUandVbeRiemannianmanffolds,withthedimensionn1andn2respectively.UxVistheRiemannianproductofUandV.WedenotebyPandQtheprojectionmappingsofT(UxV)toTUaildTVrespectively.ThenwehaveWeputJ=P-Q.ItiseasytoseethatJ~=I.WedefineaRiemannianmetricofUxVbyg(X,Y)==g1(PX,PY) g2(QX,QY),wllereg1andg2areRiemannia11metricofUandVrespectively.ItfollowsthatBy7wedellotetheg'sLevi-Civitaconnection.ThenwecaneasilyseethatInfact,Frollltlledefillitiollofg,wecangetthatUalldVareallgeodesicsub… 相似文献
23.
K.B. Nichols M.A. Venkataramanan K.W. Ernstberger 《Mathematical and Computer Modelling》2005,42(13):1397-1410
A model for the product line selection and pricing problem (PLSP) is presented andthree solution procedures based on a genetic algorithm are developed to analyze the results based on consumer preference patterns. Since the PLSP model is nonlinear and integer, two of the solution procedures use genetic encoding to “relax” the NP hard model. The relaxations result in linear integer and shortest path models for the fitness evaluation which are solved using branch and bound and labeling algorithms, respectively. Performance of the quality of solutions generated by the procedures is evaluated for various problem sizes and customer preference structures. The results show that the genetic relaxations provide efficient and effective solution methodologies for the problem, when compared to the pure artificial intelligence technique of genetic search. The impact of the preference structure on the product line and the managerial implications of the solution characteristics generated by the genetic relaxations are also discussed. The models can be used to explicitly consider tradeoffs between marketing and operations concerns in designing a product line. 相似文献
24.
Nico M. Van Dijk 《商业与工业应用随机模型》1990,6(2):85-100
This paper studies a system of parallel service facilities or processors with mixed exponential and non-exponential queues, a non-exponential finite source input and interdependent arrival as well as departure blocking such as due to a common pool or shared resource. A concrete invariance condition upon the blocking protocol is provided. Under this condition the stationary busy source distribution is shown to be of an insensitive product form. The result unifies and extends known product form results as will be illustrated by several examples. 相似文献
25.
Saradhi Kalari Dattatraya A. Babar Uttam B. Karale Vitthal B. Makane Haridas B. Rode 《Tetrahedron letters》2017,58(29):2818-2821
A simple, mild, and ecofriendly protocol for a palladium-catalysed direct arylation of imidazo[1,2-a]pyridines with aryl halides on water is reported. This protocol does not require any ligand and tolerate variety of functional groups on both the coupling partners. The simple base KOH is highly efficient in this transformation. 相似文献
26.
碳四液化气在离子浸渍改性纳米HZSM-5沸石上的转化反应研究 总被引:1,自引:1,他引:0
在小型常压固定床反应器中研究了不同离子浸渍改性对纳米ZSM-5固体酸催化剂上丁烷和丁烯转化的影响.结果表明,混和碳四中异丁烷比正丁烷易转化,丁烯异构体的转化与其在原料中的含量有关.在贫烯烃原料中,丁烯倾向于生成.在富丁烯原料中,丁烯倾向于转化.但在两种情况下,产物中各丁烯含量大体上按异丁烯、顺反-丁烯-2和丁烯-1顺序递减.采用锌离子改性时异丁烷转化率提高、正丁烷转化率降低.锌离子改性有利于芳烃选择性,但是副产物甲烷和乙烷的产率也较高;铁离子改性对丁烷和丁烯的转化影响不大,但能减少甲烷和乙烷的生成,并提高芳烃选择性;与锌改性相比,锌钠双离子改性降低了异丁烷、正丁烷和丁烯-1的转化率,减少了芳烃产率,但能明显促进丙烯和丁烯的生成.上述结果为碳四液化气综合利用提供了有益信息. 相似文献
27.
28.
When products are coupled to the same cycle, the joint replenishment model (JRM) is used to determine optimal inventory levels, where the amount to order (for each item) is designed to minimize the joint holding and ordering costs based on a given demand. JRM studies assume that there is no substitution between items. However, this assumption is unrealistic in some settings where substitution cannot be ignored. This paper combines the separate works on substitution and joint replenishment and proposes a solution procedure for solving the joint replenishment model with substitution (JRMS) for two products within the framework of the classical economic order quantity model. We determine the optimal order quantities for each product taking into consideration substitution between them so that demand is partially met and the total cost associated with the delivery, holding, and shortage of the products is minimized. We also provide an extensive scenario analysis and draw insights. In particular, we shed some light on the role of substitution in reducing the fixed cost. We show that JRMS can result in substantial cost savings compared to the ordinary JRM. 相似文献
29.
SOME RESULTS ABOUT COVERING PROPERTIES OF PRODUCTS 总被引:3,自引:0,他引:3
SOME RESULTS ABOUT COVERING PROPERTIES OF PRODUCTS ¥JIANGJIGUANG;TENGHUIAbstract:Thefollowingresultsareproved:1.LetXbeascreen... 相似文献
30.
王立春 《数学物理学报(A辑)》2006,26(6):938-947
该文运用经验贝叶斯(empirical Bayes(简称EB))方法,在历史样本和当前样本均被另一个具有未知分布的变量随机右删失的条件下,构造了一个指数分布参数的经验贝叶斯估计并获得了它的渐近最优性.文章最后给出了一个例子和模拟结果. 相似文献