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11.
G. Bilalbegović 《Zeitschrift für Physik B Condensed Matter》1987,69(1):117-120
The interfacial tension of a three-dimensional Ising model in the whole temperature region is calculated by the real-space renormalisation group methods. The cumulant and the finite-cluster approximations with different projection rules are used. The results are consistent with expected low-temperature and global behaviour of the interfacial tension in the three-dimensional model. 相似文献
12.
The IR finite one-loop box scalar integral with massless internal lines has been recalculated. The result is very compact,
simple and valid for arbitrary values of the relevant kinematic variables. It is given in terms of only two dilogarithms and
a few logarithms, all of very simple arguments.
Received: 31 January 2002 / Published online: 26 April 2002 相似文献
13.
Dragomir Ž. Đoković 《Combinatorica》1994,14(3):375-377
No Hadamard matrices of order 956 appear in the literature. In this note we construct two such matrices. They are both of Goethals-Seidel type. As a consequence of this and of a result of Seberry and Yamada, we conclude that there exist 4-Williamson type matrices of order 1913.This work was supported by NSERC of Canada Grants A-5285 and EQP0107539. 相似文献
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We analyze the polarization changes introduced by a rotated Dove prism on the linearly polarized light, using the Jones calculus and the exact ray trace analysis. The state of polarization changes from the linear to a mildly elliptical one when a plane wave front passes through a rotated Dove prism: its semi-major axis is nearly parallel to the input plane of polarization, for any angle of prism rotation. The interferogram contrast remains high for all shearing angles in spite of polarization changes when the Dove prism is incorporated into a rotational shearing interferometer. These results are confirmed experimentally. 相似文献
16.
Skantze Petter; Ilic Marija; Gubina Andrej 《IMA Journal of Management Mathematics》2004,15(4):291-319
The restructuring of the electric utilities industry has forcedindustry participants to rethink their approach to a numberof decision processes. To manage risk and plan investment ingeneration assets, as well as to examine the efficient expansionof the current transmission grid, one needs to have a clearunderstanding of the interaction between the grid propertiesand the behaviour of the regional power markets. In this paperwe discuss a fundamental modelling approach which extracts thestochastic properties of electricity prices by modelling theimpact of physical and economic drivers affecting the production,delivery, and consumption of electricity. If the fundamentalinputs are directly observable, we can use historical data tocalibrate the model parameters. In the case of electricity,this simple and abundant set of training data can make a crucialdifference. We present the bid-based stochastic model (BSM) and look intoits application to valuing of financial derivatives, especiallyoptions based on the locational spread in electricity pricebetween two markets. The advantage of the bid-based model isthat one is able to link the capacity of the transmission line,in megawatts, directly to the correlation between electricityprices at the end nodes. This leads us to a valuation methodfor a locational spread option, the financial equivalent ofa physical transmission right. The model represents an improvementover standard spread option formulation in that it accountsfor the effect of the nonlinear flows in the transmission networkon the correlation and distribution of locational prices. Wealso address the question of whether financial transmissionrights can be replicated with a dynamic portfolio of forwardcontracts at the end nodes. This poses the possibility of model-based arbitrage betweenexisting forward markets and the emerging transmission rightsmarkets. Furthermore, it allows users to simulate the effectof transmission outages or expansion. For example, a for-profittransmission provider who is contemplating addition of a newtransmission line between two markets needs to know whetherhe will be able to recover the fixed cost of investing in theline by selling transmission rights to market participants.By calibrating the bid-based model according to current pricelevels and adding the capacity of the new transmission line,the transmission owner can simulate future cash flows and estimatethe profitability of the investment. 相似文献
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Marijana ?aković Zora Popović 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):m507-m509
In the title compound, [Ni(N3)2(C6H6N2O)2], the NiII atom lies on an inversion centre. The distorted octahedral nickel(II) coordination environment contains two planar trans-related N,O-chelating picolinamide ligands in one plane and two monodentate azide ligands perpendicular to this plane. Molecules are linked into a three-dimensional framework by N—H...N hydrogen bonds. 相似文献
20.
Miodrag M. Spalević 《Numerical Algorithms》2007,46(3):253-264
We have recently proposed a very simple numerical method for constructing the averaged Gaussian quadrature formulas. These
formulas exist in many more cases than the real positive Gauss–Kronrod formulas. In this note we try to answer whether the
averaged Gaussian formulas are an adequate alternative to the corresponding Gauss–Kronrod quadrature formulas, to estimate
the remainder term of a Gaussian rule. 相似文献