339 research outputs found

    Survey of the Farm Management, Focusing on the Regional Difference and Cattle Farming in Burkina Faso

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    In Burkina Faso the history using of cattle as draft power for cultivation is not long. This study was conducted to investigate the farm management, focusing on the regional difference and the presence of cattle farming in the country. Interview was carried out on 30 farms from B Province in the Centre-West Region consisting of 8 non-cattle owners (BNs) and 22 cattle owners (BCs), and on 9 farms of cattle owners from H Province in the Haut-Bassins Region (HCs) in November 2013. The average household sizes of BNs, BCs and HCs were 16.5, 27.2 and 31.3, respectively. The ratios of BNs, BCs and HCs having income sources from livestock farming equivalent to or more than crop farming were 25, 50 and 67%, respectively. The average cattle number of BCs was 8.6 and that of HCs was 50.8. The average planted areas of BNs, BCs and HCs were 4.9, 12.0 and 7.0 ha, respectively. The BCs and BNs had large planted area of millet, rice, sorghum and peanut, on the other hand, planted area of maize, sesame seed, cotton and vegetables was large in HCs. The gross income from the crop farming of BNs and BCs were 95,000 and 114,000 FCFA/year, respectively, which were higher than that of HCs: 59,000 FCFA/year. The gross income and profit from cattle farming of HCs were twice and thrice as high as those of BCs, respectively. The ratio of the gross income from cattle farming to that from total farming of BCs and HCs were high, 72 and 80%, respectively. The results suggested that cattle farming contributed to the profit of farmers in B Province, who had a low profit margin of the crop and vegetable farming due to the constraints of soil condition and climate results from the limit of precipitation

    A propensity criterion for networking in an array of coupled chaotic systems

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    We examine the mutual synchronization of a one dimensional chain of chaotic identical objects in the presence of a stimulus applied to the first site. We first describe the characteristics of the local elements, and then the process whereby a global nontrivial behaviour emerges. A propensity criterion for networking is introduced, consisting in the coexistence within the attractor of a localized chaotic region, which displays high sensitivity to external stimuli,and an island of stability, which provides a reliable coupling signal to the neighbors in the chain. Based on this criterion we compare homoclinic chaos, recently explored in lasers and conjectured to be typical of a single neuron, with Lorenz chaos.Comment: 4 pages, 3 figure

    A note on a class of problems for a higher-order fully nonlinear equation under one-sided Nagumo-type condition

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    The purpose of this work is to establish existence and location results for the higher order fully nonlinear differential equation u⁽ⁿ⁾(t)=f(t,u(t),u′(t),…,u⁽ⁿ⁻¹⁾(t)), n≥2, with the boundary conditions u^{(i)}(a) = A, for i=0,⋯,n-3, u⁽ⁿ⁻¹⁾(a) = B, u⁽ⁿ⁻¹⁾(b)=C or u^{(i)}(a)=A, for i=0,⋯,n-3, c₁u⁽ⁿ⁻²⁾(a)-c₂u⁽ⁿ⁻¹⁾(a)=B, c₃u⁽ⁿ⁻²⁾(b)+c₄u⁽ⁿ⁻¹⁾(b)=C, with A_{i},B,C∈R, for i=0,⋯,n-3, and c₁, c₂, c₃, c₄ real positive constants. It is assumed that f:[a,b]×Rⁿ⁻¹→R is a continuous function satisfying one-sided Nagumo-type conditions which allows an asymmetric unbounded behavior on the nonlinearity. The arguments are based on Leray-Schauder topological degree and lower and upper solutions method

    Delay Induced Excitability

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    We analyse the stochastic dynamics of a bistable system under the influence of time-delayed feedback. Assuming an asymmetric potential, we show the existence of a regime in which the systems dynamic displays excitability by calculating the relevant residence time distributions and correlation times. Experimentally we then observe this behaviour in the polarization dynamics of a vertical cavity surface emitting laser with opto-electronic feedback. Extending these observations to two-dimensional systems with dispersive coupling we finally show numerically that delay induced excitability can lead to the appearance of propagating wave-fronts and spirals.Comment: 5 pages, 6 figure

    Constructing solutions to the Bj\"orling problem for isothermic surfaces by structure preserving discretization

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    In this article, we study an analog of the Bj\"orling problem for isothermic surfaces (that are more general than minimal surfaces): given a real analytic curve γ\gamma in R3{\mathbb R}^3, and two analytic non-vanishing orthogonal vector fields vv and ww along γ\gamma, find an isothermic surface that is tangent to γ\gamma and that has vv and ww as principal directions of curvature. We prove that solutions to that problem can be obtained by constructing a family of discrete isothermic surfaces (in the sense of Bobenko and Pinkall) from data that is sampled along γ\gamma, and passing to the limit of vanishing mesh size. The proof relies on a rephrasing of the Gauss-Codazzi-system as analytic Cauchy problem and an in-depth-analysis of its discretization which is induced from the geometry of discrete isothermic surfaces. The discrete-to-continuous limit is carried out for the Christoffel and the Darboux transformations as well.Comment: 29 pages, some figure

    Effect Of Planting Device And Seed Sorting On Yield Of Maize

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    ABSTRACT: Experiments were conducted at the CSIR-Crops Research Experimental station at Kumasi, Ghana, to determine the effects of seed sorting and planting device on yield of maize in the 2014 major growing season. Two jab planters were used to plant sorted and unsorted seeds. The control treatment was cutlass planting of unsorted seed. One of the jab planters was imported from China; and the other was fabricated in Ghana. The experimental design was a randomized complete block with 3 replications. Planting one hectare of maize with the Chinese planter took about 10 hours, 36 minutes; the local planter took 12 hours 39 minutes, whilst cutlass took 29 hours 36 minutes. Seed sorting and planting device had no significant effect on maize yield. However it was faster, cheaper and economically more viable to plant with jab planter than with cutlass

    Invariance Conditions for Nonlinear Dynamical Systems

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    Recently, Horv\'ath, Song, and Terlaky [\emph{A novel unified approach to invariance condition of dynamical system, submitted to Applied Mathematics and Computation}] proposed a novel unified approach to study, i.e., invariance conditions, sufficient and necessary conditions, under which some convex sets are invariant sets for linear dynamical systems. In this paper, by utilizing analogous methodology, we generalize the results for nonlinear dynamical systems. First, the Theorems of Alternatives, i.e., the nonlinear Farkas lemma and the \emph{S}-lemma, together with Nagumo's Theorem are utilized to derive invariance conditions for discrete and continuous systems. Only standard assumptions are needed to establish invariance of broadly used convex sets, including polyhedral and ellipsoidal sets. Second, we establish an optimization framework to computationally verify the derived invariance conditions. Finally, we derive analogous invariance conditions without any conditions

    A Singular Differential Equation Stemming from an Optimal Control Problem in Financial Economics

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    We consider the ordinary differential equation x2u′′=axu′+bu−c(u′−1)2,x∈(0,x0), with a∈R,b∈R , c>0 and the singular initial condition u(0)=0, which in financial economics describes optimal disposal of an asset in a market with liquidity effects. It is shown in the paper that if a+b0 then there are infinitely many continuous solutions with indistinguishable asymptotics near 0. Moreover, it is proved that in the latter case there is precisely one solution u corresponding to the choice x 0=∞ which is such that 0≤u(x)≤x for all x>0, and that this solution is strictly increasing and concave
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