Le Matematiche (Dipartimento di Matematica e Informatica, Università degli Studi di Catania)
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Surfaces of general type with vanishing geometric genus from double planes
Full text linkWe show how to construct some old and new surfaces of general typewith vanishing geometric genus from double planes,by computing explicit equations of their branch curves
Nef vector bundles on a projective space with first Chern class 3 and second Chern class 8
Full text linkWe describe nef vector bundles on a projective space with first Chern class three and second Chern class eight over an algebraically closed field of characteristic zero by giving them a minimal resolution in terms of a full strong exceptional collection of line bundles
Coefficient estimates for a certain subclass of bi-univalent functions
Full text linkIn the present investigation, we find estimates on the coefficients |a₂| and |a₃| for functions in the function class S_{Σ}(λ,h). The results presented in this paper improve or generalize the recent work of Magesh and Yamini
The Rubin\u27s q-wavelet packets
Full text linkUsing the q-harmonic analysis associated with the q-Rubin operator, we study three types of q-wavelet packets and their corresponding q-wavelet transforms. We give for these wavelet transforms the related Plancherel and inversion formulas as well as their q-scale discrete scaling functions
Addendum to "The convex hull-like property and supported images of open sets"
Full text linkIn this addendum, we remark that, applying Theorem 1.5 of [2] jointly with a very recent result by J. Saint Raymond ([3]), one can remarkably improve Theorem 3.3 of [2]
Sufficient condition for generalized Sakaguchi type spiral-like functions
Full text linkIn the present paper, the author defines a class of analytic generalized Sakaguchi type spiral-like functions on the open unit disk U and obtain certain sufficient condition for functions to be in this class. Several corollaries and consequences of the main results are also considered
A deterministic inventory model for non-instantaneous deteriorating items with ramp-type demand rate and shortages under permissible delay in payments
Full text linkIn this paper, we propose an appropriate inventory model for a non-instantaneous deteriorating items having Ramp-type demand rate with time dependent deterioration rate. In this model, the shortages are allowed and, which is partially backlogged. The backlogging rate is variable and time dependent on the waiting time for the next replenishment. One of the best tools for delaying cash outflow of any cash-strapped or new retail business is the trade credit or delay in payments available from suppliers. This model serves in minimizing the total inventory cost by finding an optimal replenishment policy. Some useful lemmas have been delineated to illustrate the optimal solution. Several numerical examples are given to test and verify the theoretical results. The sensitivity analysis of the optimal solution with respect to major parameters is developed. Finally, the managerial implications and conclusion are presented
A Fractional Landesman-Lazer type problem set on \R^{N}
Full text linkBy using the abstract version of Struwe’s monotonicity-trick we prove the existence of a positive solution to the problem.
Existence and multiplicity of non-zero solutions for the Neumann problem via spherical maxima
Full text linkIn this paper, we are interested inthe existence and multiplicity of non-zerosolutions for a two-point boundary value problems subject to Neumannconditions. Our approach is based on a result on spherical maxima sharing the same Lagrange multiplier that was established recently by Ricceri
Minimal edge colorings of class 2 graphs and double graphs
Full text linkA proper edge coloring of a class 2 graph G is minimal if it contains a color class of cardinality equal to the resistance r(G) of G, which is the minimum number of edges that have to be removed from G to obtain a graph which is Δ(G)-edge colorable, where Δ(G) is the maximum degree of G. In this paper using some properties of minimal edge colorings of a class 2 graph and the notion of reflective edge colorings of the direct product of two graphs, we are able to prove that the double graph of a class 2 graph is of class 1. This result, recently conjectured, is moreover extended to some generalized double graphs