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991.
Giampio Bracchi Chiara Francalanci 《Computational & Mathematical Organization Theory》1997,3(3):173-198
This paper proposes a formal model of information processing inorganizations. The model takes a process view of organizations and includesboth structural and IS features of processes. Two structural properties areconsidered, networking and parallelism. Information systems are representedin terms of quantity of information used and level of informationcustomization allowed. Process performance is measured in terms of totalinformation processing capacity and flexibility afforded by a process. Therelationship between structural and information system choices and processperformance is studied by simulating the model for a range of values. Thepaper derives a set of propositions describing the independent and combinedimpact of structural and information system choices on performance. The results suggest the predominance of networking over parallelism and ofinformation customization over information quantity in determininginformation processing capacity. They also show a negative effect ofnetworking on process flexibility and an amplifying effect of networking onthe benefits of information customization. Overall, the findings validatethe interdependence between structural and information system variables indetermining process performance. 相似文献
992.
S. R. Nasyrov 《Siberian Mathematical Journal》2008,49(5):894-910
We obtain some estimates for the distortions of the moduli of quadrilaterals, the reduced moduli, and Robin capacities depending on the variation of the boundary of a domain. We show that for sufficiently smooth variations of the boundary the corresponding variations of the moduli and capacities are proportional to the area of the variable part of the domain in some extremal metric. We apply these results to studying the generalized Lavrent’ev problem of finding the shape of an infinitely thin airfoil of given length with the maximal aerodynamical lift under some restriction on the curvature of the airfoil. 相似文献
993.
Ronald Adelmann Petra Mela Marat O. Gallyamov Helmut Keul Martin Möller 《Journal of polymer science. Part A, Polymer chemistry》2009,47(5):1274-1283
P(BMA‐co‐HEMA‐spiropyran) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization of butyl methacrylate (BMA) and 2‐(trimethylsilyloxy)‐ethyl methacrylate (HEMA‐TMS), removal of the TMS‐protective groups, and the polymer analogous esterification of the hydroxyethyl side chains with a spiropyran containing a carboxylic acid group. UV‐induced conformational changes of the synthesized macromolecules and low‐molecular‐weight spiropyran molecules were studied. Rate constants and half‐life times of the ring closure reaction from zwitterionic merocyanine to the spiropyran species were determined in the presence and absence of mica‐dispersed particles in toluene both with the free spiropyran and the polymer‐bound spiropyran. Scanning force microscopy was used to visualize the conformation of spiropyran‐decorated single macromolecular chains and agglomerated polymer‐bound merocyanine adsorbed on mica. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1274–1283, 2009 相似文献
994.
The thermo-viscoplastic behavior of three metals is characterized in a large range of loading conditions by using a new phenomenological
constitutive model. The flow stress is decomposed into the sum of an effective stress with an internal stress depending upon
an internal parameter which describes the strain hardening effect. The evolution of the internal stress is sensitive to the
history of strain-rate and temperature. A systematic method is used for determining the model’s parameters. The model predictions
show a good correlation with experimental data. Temperature history effects are especially analyzed. 相似文献
995.
Xiaoze Jiang Jingyan Zhang Yueming Zhou Jian Xu Shiyong Liu 《Journal of polymer science. Part A, Polymer chemistry》2008,46(3):860-871
Double hydrophilic diblock copolymer, poly(N,N‐dimethylacrylamide)‐b‐poly(N‐isopropylacrylamide‐co‐3‐azidopropylacrylamide) (PDMA‐b‐P(NIPAM‐co‐AzPAM), containing azide moieties in one of the blocks was synthesized via consecutive reversible addition‐fragmentation chain transfer polymerization. The obtained diblock copolymer molecularly dissolves in aqueous solution at room temperature, and can further supramolecularly self‐assemble into core‐shell nanoparticles consisting of thermoresponsive P(NIPAM‐co‐AzPAM) cores and water‐soluble PDMA coronas above the lower critical solution temperature of P(NIPAM‐co‐AzPAM) block. As the micelle cores contain reactive azide residues, core crosslinking can be facilely achieved upon addition of difunctional propargyl ether via click chemistry. In an alternate approach in which the PDMA‐b‐P(NIPAM‐co‐AzPAM) diblock copolymer was dissolved in a common organic solvent (DMF), the core‐crosslinked (CCL) micelles can be fabricated via “click” crosslinking upon addition of propargyl ether and subsequent dialysis against water. CCL micelles prepared by the latter approach typically possess larger sizes and broader size distributions, compared with that obtained by the former one. In both cases, the obtained (CCL) micelles possess thermoresponsive cores, and the swelling/shrinking of which can be finely tuned with temperature, rendering them as excellent candidates as intelligent drug nanocarriers. Because of the high efficiency and quite mild conditions of click reactions, we expect that this strategy can be generalized for the structural fixation of other self‐assembled nanostructures. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 860–871, 2008 相似文献
996.
997.
This paper applies financial option valuation methods to new wireless network capacity investment decision timing. In particular, we consider the case of network capacity for cellular telephone service. Given a cluster of base stations (with a certain traffic capacity per base station), we determine when it is optimal to increase capacity for each of the base stations contained in the cluster. We express this in terms of the fraction of total cluster capacity in use, i.e. we calculate the optimal time to upgrade in terms of the ratio of observed usage to existing capacity. We study the optimal decision problem of adding new capacity in the presence of stochastic wireless demand for services. A four factor algorithm is developed, based on a real options formulation. Numerical examples are provided to illustrate various aspects of the model. 相似文献
998.
资源区经济与资源环境承载力与可持续发展研究 总被引:1,自引:0,他引:1
承载力理论与可持续发展理论密切相关,是可持续发展理论的一个重要组成部分.本文以系统思想为指导,从理论上分析了经济与环境、资源发展的关系;通过实证分析,对资源区进行了定性和定量的研究. 相似文献
999.
采用定向棱镜谐振腔、半圆柱面LD阵列交错侧向泵浦两根串接NdYAG激光棒、热传导冷却结构,研制出了一台工程实用的全固化激光器.定向棱镜腔内振荡光线平行于光轴的对称位置交换穿行,匀化了增益,降低了模序数;同时,定向棱镜准相位共轭特性和自准直作用在一定程度上修正波前畸变、热光楔以及热致双折射,保证了大的动态范围内热稳定性,改善了光束质量.激光器采用Cr4+YAG被动调Q,在室温条件下,工作电流为53 A、频率10 Hz时,1.06 μm单脉冲激光能量高于150 mJ、脉宽9 ns、输出稳定度±3%、束散度2.5 mrad且光轴指向稳定,远场分布近似相干平顶高斯光束. 相似文献
1000.
Conditions are studied under which the contribution of the singular part of a measure to the (1,p)-capacity of an arbitrary condenser is zero. 相似文献