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51.
We study N-queues single-server fluid polling systems, where a fluid is continuously flowing into the queues at queue-dependent rates. When visiting and serving a queue, the server reduces the amount of fluid in the queue at a queue-dependent rate. Switching from queue i to queue j requires two random-duration steps: (i) departing queue i, and (ii) reaching queue j. The length of time the server resides in a queue depends on the service regime. We consider three main regimes: Exhaustive, Gated, and Globally-Gated. Two polling procedures are analyzed: (i) cyclic and (ii) probabilistic. Under steady-state, we derive the Laplace–Stieltjes transform (LST), mean, and second moment of the amount of flow at each queue at polling instants, as well as at an arbitrary moment. We further calculate the LST and mean of the “waiting time” of a drop at each queue and derive expressions for the mean total load in the system for the various service regimes. Finally, we explore optimal switching procedures. 相似文献
52.
53.
Sutapa Ghosh Jason D. Jennissen Xing-Ping Liu Fatih M. Uckun 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):76-78
The title compounds, C16H15BrN3O3+·Cl−·CH4O (WHI–P154) and C16H16N3O3+·Cl− (WHI–P180), are potent inhibitors [WHI–P154 with IC50 = 5.6 µM and WHI–P180 with IC50 = 4.0 µM for epidermal growth factor receptor (EGFR) kinase inhibition] of the EGFR tyrosine kinase as well as Janus Kinase 3. The molecular structures of these compounds are very similar except for the dihedral angle between the anilino and quinazoline moieties which is 1.10 (5)° for WHI–P154, and 45.66 (6) and 25.29 (7)° for the two molecules of WHI–P180 in the asymmetric unit. The nitrogen at the N3 position is protonated in both structures and participates in hydrogen bonding with the chlorine anions. 相似文献
54.
Most macroeconomic time series are reported on a quarterly basis. However, in many cases, official statistical agencies report annual (or ‘year-on-year’) growth rates rather than the quarterly data themselves. In this paper, we demonstrate how to recover seasonally adjusted quarterly growth rates from annual growth rates that are reported quarterly. As an illustration, we apply the technique to the highly seasonal UK Retail Sales series. Using only the annual growth rates calculated from the underlying data, we find that our procedure generates estimated seasonally adjusted quarterly growth rates that are almost indistinguishable from the ‘true’ seasonally adjusted quarterly growth rates. 相似文献
55.
Avcı Davut Altürk Sümeyye Sönmez Fatih Tamer Ömer Başoğlu Adil Atalay Yusuf Zengin Kurt Belma Dege Necmi 《Molecular diversity》2021,25(1):171-189
Molecular Diversity - The World Health Organization (WHO) report shows that diabetes mellitus (DM) will be one of the ten deadly diseases in the near future. The best way to prevent DM is to... 相似文献
56.
Selçuk Demir Hamide Merve Çepni Małgorzata Hołyńska Muammer Kavanoz Fatih Yilmaz Yunus Zorlu 《Journal of Coordination Chemistry》2017,70(19):3422-3433
Via an oxidation reaction of Cu(I) iodide with pyridine-2,6-dicarboxylic acid (H2L) in DMF three copper(II) complexes, [(CH3)2NH2]2[CuL2] (1), K2[CuL2]?H2L?H2O (2) and [Cu(L)(H2O)]n (3), were synthesized and characterized. The structures of 1–3 were determined by single crystal X-ray diffraction studies. In-situ DMF decomposition produces dimethylamine base under solvothermal conditions and a proton transfer reaction takes place for the complex formation of 1. 3-D networks are stabilized in 1 and 2 via hydrogen bonds. Complex 3 is a 1-D coordination polymer with Cu-O semi-coordination bonds. Thermal decomposition of the complexes results in the corresponding metal oxides. Also, the electrochemical behavior of 1 was determined to be a metal-centered and diffusion-controlled, one-electron reduction process. 相似文献
57.
The effects of gamma irradiation on crystallization kinetics and microhardness properties of the Li2O–Al2O3–SiO2 (LAS) glass–ceramic sample have been investigated. The glass–ceramic was irradiated to γ-source 60Co of 0.7 MGy. The crystallization kinetics of the irradiated and non-irradiated samples were characterized using differential
scanning calorimetry. The crystallization kinetics and microhardness properties of the glass–ceramic changed the gamma irradiation,
and the high dose of gamma irradiation affects significantly the crystallization kinetics and microhardness properties of
the Li2O–Al2O3–SiO2 glass–ceramic sample. 相似文献
58.
Güneş Y Polat MF Sahin E Fleming FF Altundas R 《The Journal of organic chemistry》2010,75(21):7092-7098
Quaternary oxonitriles are stereoselectively generated from the union of five-, six-, and seven-membered 2-chloroalkenecarbonitriles with chiral alcohols via a Claisen rearrangement. The strategy rests on a new conjugate addition-elimination of allylic alkoxides to 2-chlorocycloalkenecarbonitriles to afford substituted 2-alkoxyalkenenitriles. Subsequent thermolysis unmasks a cyclic oxonitrile while selectively forming a new quaternary center with enantiomeric ratios typically greater than 9:1. The overall alkylation strategy addresses the challenge of enantioselectively generating hindered, quaternary centers while simultaneously installing ketone, nitrile, and olefin functionalities. 相似文献
59.
Ezhil Jothinathan Kim VanmeenselJef Vleugels Tamara KharlamovaVladislav Sadykov Svetlana PavlovaGeorgia Sourkouni Christian SzepanskiChristos Argirusis Omer Van der Biest 《Solid State Ionics》2011,192(1):419-423
Apatite type rare earth silicates are being extensively studied as electrolyte material for intermediate temperature solid oxide fuel cells (SOFC). In this paper we presents results on synthesis of Al and/or Fe-doped ATLS, the design of compatible anode materials, thermal expansion properties and co-sintering of half-cells from expansion matched materials using the advanced pulsed electric current sintering (PECS) technique. The issues related to the co-sintering of half cells have been addressed successfully by the combined use of nano powders and PECS. 相似文献
60.
This paper presents a novel discrete artificial bee colony (DABC) algorithm for solving the multi-objective flexible job shop scheduling problem with maintenance activities. Performance criteria considered are the maximum completion time so called makespan, the total workload of machines and the workload of the critical machine. Unlike the original ABC algorithm, the proposed DABC algorithm presents a unique solution representation where a food source is represented by two discrete vectors and tabu search (TS) is applied to each food source to generate neighboring food sources for the employed bees, onlooker bees, and scout bees. An efficient initialization scheme is introduced to construct the initial population with a certain level of quality and diversity. A self-adaptive strategy is adopted to enable the DABC algorithm with learning ability for producing neighboring solutions in different promising regions whereas an external Pareto archive set is designed to record the non-dominated solutions found so far. Furthermore, a novel decoding method is also presented to tackle maintenance activities in schedules generated. The proposed DABC algorithm is tested on a set of the well-known benchmark instances from the existing literature. Through a detailed analysis of experimental results, the highly effective and efficient performance of the proposed DABC algorithm is shown against the best performing algorithms from the literature. 相似文献