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1.
S. L. Hakimi 《Annals of Operations Research》1986,6(4):75-98
In competitive location theory, one wishes to optimally choose the locations ofr facilities to compete againstp existing facilities for providing service (or goods) to the customers who are at given discrete points (or nodes). One normally assumes that: (a) the level of demand of each customer is fixed (i.e. this demand is not a function of how far a customer is from a facility), and (b) the customer always uses the closest available facility. In this paper we study competitive locations when one or both of the above assumptions have been relaxed. In particular, we show that for each case and under certain assumptions, there exists a set of optimal locations which consists entirely of nodes.This work was supported by a National Science Foundation Grant ECS-8121741. 相似文献
2.
S. ZandiP. Kameli H. SalamatiH. Ahmadvand M. Hakimi 《Physica B: Condensed Matter》2011,406(17):3215-3218
In this investigation, ZnO nanoparticles were prepared by a simple and rapid method. This method is based on the short time solid state milling and calcinations of zinc acetate and citric acid powders. The samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, photoluminescence and UV-vis spectroscopy. It was shown that the calcination temperature significantly affected the particle size and optical properties of the synthesized ZnO nanoparticles. Calculation based on the XRD data shows that the average sizes of ZnO particles are in agreement with those from TEM images and the size of the particles increases on increasing the calcination temperature. Also the band gap of samples decreased from 3.29 to 3.23 eV on increasing the calcination temperature from 350 to 600 °C. Photoluminescence analyses show that many defects such as interstitial zinc, zinc vacancy and oxygen vacancy are responsible for the observed optical properties. 相似文献
3.
Bounds are given on the number of colors required to color the edges of a graph (multigraph) such that each color appears at each vertex v at most m(ν) times. The known results and proofs generalize in natural ways. Certain new edge-coloring problems, which have no counterparts when m(ν) = 1 for all ν ? V, are studied. 相似文献
4.
5.
O. Coutier‐Delgosha R. Fortes‐Patella J. L. Reboud N. Hakimi C. Hirsch 《国际流体数值方法杂志》2005,48(2):135-167
A computational method is proposed to simulate 3D unsteady cavitating flows in spatial turbopump inducers. It is based on the code FineTurbo, adapted to take into account two‐phase flow phenomena. The initial model is a time‐marching algorithm devoted to compressible flow, associated with a low‐speed preconditioner to treat low Mach number flows. The presented work covers the 3D implementation of a physical model developed in LEGI for several years to simulate 2D unsteady cavitating flows. It is based on a barotropic state law that relates the fluid density to the pressure variations. A modification of the preconditioner is proposed to treat efficiently as well highly compressible two‐phase flow areas as weakly compressible single‐phase flow conditions. The numerical model is applied to time‐accurate simulations of cavitating flow in spatial turbopump inducers. The first geometry is a 2D Venturi type section designed to simulate an inducer blade suction side. Results obtained with this simple test case, including the study of its general cavitating behaviour, numerical tests, and precise comparisons with previous experimental measurements inside the cavity, lead to a satisfactory validation of the model. A complete three‐dimensional rotating inducer geometry is then considered, and its quasi‐static behaviour in cavitating conditions is investigated. Numerical results are compared to experimental measurements and visualizations, and a promising agreement is obtained. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
6.
S. Louis Hakimi Edward F. Schmeichel 《Journal of Algorithms in Cognition, Informatics and Logic》1984,5(4):526-530
Consider a system of n units, at most t of which are faulty. An adaptive diagnosis algorithm is presented which uses a sequence of tests to identify a fault-free unit. The algorithm requires at most 2t − ν(t) tests, where ν(t) is the number of 1's in the binary representation of t. Moreover, many of the tests can be performed simultaneously. The previously best algorithms for the same purpose required 2t − 1 tests, none of which could be performed simultaneously. 相似文献
7.
S. Louis Hakimi 《Journal of Graph Theory》1997,24(1):81-83
This note presents a solution to the following problem posed by Chen, Schelp, and Šoltés: find a simple graph with the least number of vertices for which only the degrees of the vertices that appear an odd number of times are given. © 1997 John Wiley & Sons, Inc. 相似文献
8.
S. Syed Hakimi 《Journal of Radioanalytical and Nuclear Chemistry》1996,214(2):117-131
Soil column experiments have been conducted to treat liquid wastes from hospitals containing125I. Three sorbent samples of laterite clay materials with different contents of iron oxides (goethite, -FeOOH) and hydroxides were used to sorb anionic iodate. Post-treatment on effluent wastes with sodium hypochlorite (redox reagent) oxidized the iodide to the desirable iodate ion. Effluent pH after treatment ranges between 4.8 to 5.8, which does not vary much from the initial effluent pH of 4.5 before treatment. Results show that 90 to 97% sorption of iodine radionuclides with a decontamination factor ranges between 10–32 was obtained after the first two hours of experiments. Concentration has decreased from the initial 10 Bq/ml to concentration ranges of 0.3 to 0.9 Bq/ml. Batch experiments conducted using different sorbent masses of soils, show that there was a drop in sorption as the mass of soils fell below approximately 0 to 0.25 g. The sorption remains constant with the soil mass above 0.25 g. Another batch experiment using a different concentration shows that the adsorption capacity of the laterite soil was 1.1 Ci/g. The adsorption is about 96% with a distribution coefficient of 1170. 相似文献
9.
Mohammad Yazdanbakhsh Mohammad Hakimi Majid M. Heravi Roland Boese 《无机化学与普通化学杂志》2006,632(14):2201-2203
The reaction of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione with AgNO3 in methanol led to the complex [Ag(ATT)2]NO3 ( 2 ). 2 was characterized by elemental analyses, IR, 1HNMR and Raman spectroscopy as well as single‐crystal X‐ray diffraction. Crystal data for 2 at ?70 °C: space group P21/n with a = 1356.7(12), b = 770.4(7), c = 1475.2(12) pm, β = 111.730(15)°, Z = 4, R1 = 0.0402. 相似文献
10.
Zahra Mardani Mohammad Hakimi Keyvan Moeini Fabian Mohr 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(7):951-959
The reaction between 2‐[2‐(aminoethyl)amino]ethanol and pyridine‐2‐carbaldehyde in a 1:2 molar ratio affords a mixture containing 2‐({2‐[(pyridin‐2‐ylmethylidene)amino]ethyl}amino)ethanol (PMAE) and 2‐[2‐(pyridin‐2‐yl)oxazolidin‐3‐yl]‐N‐(pyridin‐2‐ylmethylidene)ethanamine (POPME). Treatment of this mixture with copper(II) chloride or cadmium(II) chloride gave trichlorido[(2‐hydroxyethyl)({2‐[(pyridin‐2‐ylmethylidene)amino]ethyl})azanium]copper(II) monohydrate, [Cu(C10H16N3O)Cl3]·H2O or [Cu(HPMAE)Cl3]·H2O, 1 , and dichlorido{2‐[2‐(pyridin‐2‐yl)oxazolidin‐3‐yl]‐N‐(pyridin‐2‐ylmethylidene)ethanamine}cadmium(II), [CdCl2(C16H18N4O)] or [CdCl2(POPME)], 2 , which were characterized by elemental analysis, FT–IR, Raman and 1H NMR spectroscopy and single‐crystal X‐ray diffraction. PMAE is potentially a tetradentate N3O‐donor ligand but coordinates to copper here as an N2 donor. In the structure of 1 , the geometry around the Cu atom is distorted square pyramidal. In 2 , the Cd atom has a distorted octahedral geometry. In addition to the hydrogen bonds, there are π–π stacking interactions between the pyridine rings in the crystal packing of 1 and 2 . The ability of PMAE, POPME and 1 to interact with ten selected biomolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B‐DNA) was investigated by docking studies and compared with doxorubicin. 相似文献