344,563 research outputs found
Pattern avoidance in partial permutations
No full textMotivated by the concept of partial words, we introduce an analogous concept of partial permutations. A partial permutation of length n with k holes is a sequence of symbols in which each of the symbols from the set {1,2,...,n-k} appears exactly once, while the remaining k symbols of are "holes". We introduce pattern-avoidance in partial permutations and prove that most of the previous results on Wilf equivalence of permutation patterns can be extended to partial permutations with an arbitrary number of holes. We also show that Baxter permutations of a given length k correspond to a Wilf-type equivalence class with respect to partial permutations with (k-2) holes. Lastly, we enumerate the partial permutations of length n with k holes avoiding a given pattern of length at most four, for each n >= k >= 1
Experimental investigation into the propagation of partial discharge pulses in transformers
No full textAn experimental investigation into the propagation behaviour of partial discharge (PD) pulses in a continuous disc type 6.6kV transformer winding is described in this paper. PD pulses were injected into the winding using a calibrator and the resulting current signals at the line and neutral end terminals measured using wide band current transformers. The location of the troughs (or zeros) in the frequency spectra of the measured signals change in accordance with the position of the injected pulse. The crests (or poles) in the spectra convey information about the resonance frequencies of the winding and are not affected by the position of the injected pulse. The measured spectra are compared with the spectra generated by a simulation model and although differences exist the overall shape and location of the poles and zeros are similar
Global extrapolation procedures for linear partial differential equations
No full textGlobal extrapolation procedures, in space and time are considered for the numerical Solution of linear partial differential equations. Global extrapolation procedures in time only are reviewed.
The procedures are tested on three problems from the literature, one of which has a nonlinear source term
The Partial Distribution: Definition, Properties and Applications in Economy
No full textIn this discussed draft, we want to present the Partial Distribution (F.Dai, 2001) for discussing. We compare the partial distribution with lognormal and levy distribution. Though the levy distribution is better to describe the prices distribution of stock and stock indexes in a moderately large volatility range, the lognormal is better in a region of low values of volatility. We shall try to elucidate that the Partial Distribution is better than lognormal distribution in many respects. From partial distribution, we can acquire lots of interesting results, such as, describing the probability that stock price become zero if corresponding company collapses or the commodity price become zero if it lapses, expressing the average selling price of a commodity or stocks as the cost and average profits, and offering the accurate analytic model of American puts options pricing, etc. there are some related studies in appendix.partial distribution, economic analysis, commodity pricing, American puts option, accurate pricing formula
Partial Cooperation and Non-Signatories Multiple Decision
No full textIn this paper we investigate partial cooperation between a portion of the players and the rest of the players who do not cooperate and play a Nash game having multiple equilibria. Some properties of the partial cooperative equilibrium are studied and applied to a public goods situation.noncooperative games, cooperation, public goods games
A family of difference schemes for fourth order parabolic partial differential equations
No full textA family of methods is developed for the numerical solution of fourth
order parabolic partial differential equations in one- and two-space
variables. The methods are seen to evolve from multiderivative methods
for second order ordinary differential equations.
The methods are tested on three model problems, with constant
coefficients and variable coefficients, which have appeared in the literature
The numerical solution of elliptic and parabolic partial differential equations with boundary singularities
No full textA general numerical method is described for the solution of linear elliptic and parabolic partial differential equations in the presence of boundary singularities. The method is suitable for use with either a finite-difference or finite element scheme. Modified approximations for the derivatives are developed using the local analytical form of the singularity. General guidelines are given showing how the local analytical form can be found and how the modified approximations can be developed for many problems of mathematical physics. These guidelines are based on the reduction of the differential equation to the form Δu = gu + f. The potential problem treated by Motz and Woods is taken as a numerical example. The numerical results compare favourably with those obtained by other techniques
A model of university choice: an exploratory approach
No full textIn order to attract the best students, institutions of higher education need to understand how students select colleges and universities (Kotler and Fox, 1995). Understanding the choice process of a university is an instrument with high potential for developing universities marketing strategies (Plank and Chiagouris, 1997). Although many studies have tried to investigate which criteria students use to select a college or university, few have tried to analyse this trough a model that allows the interaction of all these criteria. This study presents a model of university choice, analysed through structural equations modelling using the Partial Least Squares approach.Marketing; student recruitment and selection; high institution development; strategic planning
Incentives for Partial Acquisitions and Real Market Concentration
No full textWe analyze the incentives of a controlling shareholder of a firm to acquire, directly or indirectly through his firm, shares in a competitor. We charaterize the conditions under which these partial acquisitions as well as the equilibrium toehold and its nature: controlling or silent. We find that while this shareholder gains, the acquisition is detrimental to minority shareholders of his firm, or of the target, or even of both. We show that the incentives are enhanced if the dominant shareholder initially holds silent stakes in rivals while controlling interests may discourage them. Moreover, we find that partial acquisitions always lead to a decrease in the joint profit of the two firms involved, and an increase in competitor's profits as the market becomes less competitive.horizontal partial acquisitions ; real market concentration ; dominant shareholder ; minority shareholders ; silent interests.
Extrapolation techniques for first order hyperbolic partial differential equations
No full textA uniform grid of step size h is superimposed on the space variable x in the first order hyperbolic partial differential equation ∂u/∂t + a ∂u/∂x = 0 (a > 0, x > 0, t > 0). The space derivative is approximated by its backward difference and central difference replacements and the resulting linear systems of first order ordinary differential equations are solved employing Padé approximants to the exponential function.
A number of difference schemes for solving the hyperbolic equation are thus developed and each is extrapolated to give higher order accuracy.
The schemes, and their extrapolated forms, are applied to two problems, one of which has a discontinuity in the solution across a characteristic
- …
