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Miguel A. Goberna Mercedes Larriqueta Virginia N. Vera de Serio 《Journal of Computational and Applied Mathematics》2008
Many mathematical programming models arising in practice present a block structure in their constraint systems. Consequently, the feasibility of these problems depends on whether the intersection of the solution sets of each of those blocks is empty or not. The existence theorems allow to decide when the intersection of non-empty sets in the Euclidean space, which are the solution sets of systems of (possibly infinite) inequalities, is empty or not. In those situations where the data (i.e., the constraints) can be affected by some kind of perturbations, the problem consists of determining whether the relative position of the sets is preserved by sufficiently small perturbations or not. This paper focuses on the stability of the non-empty (empty) intersection of the solutions of some given systems, which can be seen as the images of set-valued mappings. We give sufficient conditions for the stability, and necessary ones as well; in particular we consider (semi-infinite) convex systems and also linear systems. In this last case we discuss the distance to ill-posedness. 相似文献
84.
Vincenzo Cunsolo Elisa Cairone Rosaria Saletti Vera Muccilli Salvatore Foti 《Rapid communications in mass spectrometry : RCM》2009,23(13):1907-1916
Two coeluting components, with experimentally measured Mr values of 25529 and 24606 Da, were identified by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) and mass spectrometric analysis in the dephosphorylated casein fraction of a milk sample collected from an individual donkey belonging to the Ragusano breed of the east of Sicily. By coupling enzymatic digestions, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) and RP‐HPLC/nano‐electrospray ionization tandem mass spectrometry (nESI‐MS/MS) analysis, the two proteins were identified as donkey β‐CNs and their sequences characterized completely, using the two known β‐CNs from mare as references. The two donkey β‐CNs, showing a mass difference of 923 Da, differ by the presence of the domain E27SITHINK34 in the full‐length component (Mr 25529 Da). In comparison with the mare's β‐CNs used as reference, they present nine amino acid substitutions: L→S37, R→H52, S→N81, P→V84, L→V91, R→Q203, P→L/I206, L→F210 and A→P219. Together, these substitutions account for the increase of 18 Da in the Mr of the donkey β‐CNs with respect to the counterparts from the mare. The molecular mass determination by ESI‐MS for the phosphorylated proteins showed that the full‐length component was composed of highly multi‐phosphorylated isoforms with five to seven phosphate groups. By analogy with the homologous mare's β‐CNs, the full‐length (226 amino acids) β‐CN was termed variant A, whereas the shorter (218 amino acids) β‐CN was termed variant AΔ5. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
85.
Lubov' V. Snegur Yury S. Nekrasov Nataliya S. Sergeeva Zhanna V. Zhilina Vera V Gumenyuk Zoya A. Starikova Alexander A. Simenel Nataliya B. Morozova Irina K. Sviridova Valery N. Babin 《应用有机金属化学》2008,22(2):139-147
The toxicity of ferrocenylethyl benzotriazole ( 1 ) and other ferrocene compounds including ferrocenylmethyl benzimidazoles ( 4,5,6,11 ), ferricenium salts ( 3,9,10 ) and ferrocenylmethyl adenine ( 7 ), was studied. All ferrocene complexes under investigation showed low or medium toxicities. On the basis of an earlier model of chemical carcinogenesis, the antitumor activity of ferrocenylalkyl azoles 1, 8 and ferricenium salts 9, 10 was studied in vivo in the so‐called sub‐capsular test on human tumors. This effectiveness was compared with that of cisplatin. A series of ferrocenylalkyl azoles were synthesized by interacting azoles either with α‐hydroxyalkyl ferrocenes FcC(OH)R1R2 in organic solvent in the presence of aqueous HBF4 in quantitative yields or with trimethyl(aminomethyl)ferrocene iodide in an aqueous‐basic medium in good yields. The X‐ray determinations of molecular and crystal structures of α‐(1‐benzotriazolyl)ethylferrocene ( 1 ) and α‐(1‐naphthatriazolyl)ethylferrocene ( 12 ) were performed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
86.
This paper contributes to the supply chain contracts literature in economics and operations by performing qualitative sensitivity analysis of a wholesale price contract in a two-echelon supply chain setting. Order-theory tools are used to derive sufficient conditions for monotonicity of contract parameters.The upstream supplier is modeled as a Stackelberg leader. The supplier is assumed to have complete information about the costs and revenue function of the downstream retailer. It is shown that an equilibrium wholesale price weakly increases with an increase in the supplier production cost rate, but it may increase or decrease with an increase in the retailer cost rate. As either the supplier production cost or the retailer cost increases, the supplier profit decreases weakly. Additional sensitivity analysis is performed assuming certain properties of the retailer revenue function.Several well-known results in the supply chain contracting literature can be considered as special cases of the more general theorems developed here. In particular, this paper reexamines the analysis of a newsvendor supply chain problem by Lariviere and Porteus [Lariviere, M.A., Porteus, E.L., 2001. Selling to the newsvendor: An analysis of price-only contracts. Manufacturing & Service Operations Management 3, 293–305]. This paper generalizes and extends their work, by establishing properties of the newsvendor demand distribution that guarantee monotonicity of the contract parameters, without requiring a unique contract solution. 相似文献
87.
Antonio Vera López 《Israel Journal of Mathematics》1986,56(2):179-187
We get new properties of the numbersr G(xN) = |{Cl G (g)|Cl G (g)∩xN ≠ Ø} (whereG is a finite group andN is a normal subgroup ofG) that are useful in the analysis of the classification of the finite groups according to the number of conjugacy classes. 相似文献
88.
We report an analysis of two different clays from the region of Umbria (Italy): 1. potteries found one inside and the other
outside the town of Todi, dating from the end of the IV century B. C., 2. bond clays of Bagnara (Nocera Umbra) and Colfiorito
(Foligno) dating V century B.C. 相似文献
89.
Nenad Mladenović Milan Dražić Vera Kovačevic-Vujčić Mirjana Čangalović 《European Journal of Operational Research》2008
We suggest a new heuristic for solving unconstrained continuous optimization problems. It is based on a generalized version of the variable neighborhood search metaheuristic. Different neighborhoods and distributions, induced from different metrics are ranked and used to get random points in the shaking step. We also propose VNS for solving constrained optimization problems. The constraints are handled using exterior point penalty functions within an algorithm that combines sequential and exact penalty transformations. The extensive computer analysis that includes the comparison with genetic algorithm and some other approaches on standard test functions are given. With our approach we obtain encouraging results. 相似文献
90.