Vertical Coordination by Contracts in Agribusiness - An Empirical Research in the Hungarian Dairy Sector

In some cases spot markets failure to govern to whole or a part of the marketing channel effectively and contractual relations are gaining more importance. It is especially true in case of agricultural markets, since these markets became more differentiated and market players are vulnerable in most of the cases. Examination of Hungarian dairy sector is an actual issue, so that one could understand how contractual systems work in the situation when crises appear thanks to governance insufficiency. Our research’s aims are to present a theoretically structured framework of contracting arrangements of milk producers based on Transaction Cost Economics’ (TCE) predictions and economics of contracting and an empirical analysis of the key determinants of governance structure between farmers and dairy processors in Hungary. The source of the research is a theoretical argument based partly on review of Hungarian and international literature on relevant market channels, economics of contracting and governance structures. These gave the theoretical determinants of testable prepositions. In the framework of a postal survey in the second quarter of 2005 we carried out a survey among milk producers. A total of 300 questionnaires containing closed and open questions were sent out for milk producers, 65 of them could have been evaluated. The results have been structured, electronically converted for applying SPSS-software. The data base has been analysed by employing multivariate techniques (cluster analysis, linear regression, multidimensional scaling, etc). First, to be able to decide the number of clusters, we applied a hierarchical clustering. The formation of starting clusters was made by giving the number of the future groups which based on hierarchical cluster method and dendrogram. Hence asset specific investment, price determination and bargaining power proved to be significant in dividing the cases into three groups focusing on governance structure. We revealed the main characteristics of clusters focusing on con-tracting attributes. Groups’ means comparison obtains the result that there is no significant difference in partner change, neither in the whole sample nor in the sub-groups. Unlike from this, the reasons for selling to a particular buyer are different in the clusters, the most important factors are reliability, valid contract and the ones based on geographic reasons. The variables mentioned above were suitable for further investigations, so with the help of linear regression we attempted to see their effect on the contract period. Taking into consideration the t-values of the variables, neither asset specific investment and bargaining power, nor price determination have role in the explanation of contract period. Since the variables applied in the whole survey measure same theoretical concepts, we had the possibility to reduce their number by multidimensional scaling. The aim of this scaling is to gain information about the differences among the respondents reducing the dimensions of the variables. The goodness of fit was good in case of three and two dimensions, so we found that the six-dimensional space can be reduced into two or three dimensions without giving up the differences among cases.Contracts, dairy sector, governance structure, vertical co-ordination, agribusiness, producers’ group, co-operation, transaction cost economics, Hungary

Mean-Field- and Classical Limit of Many-Body Schr\"odinger Dynamics for Bosons

We present a new proof of the convergence of the N-particle Schroedinger dynamics for bosons towards the dynamics generated by the Hartree equation in the mean-field limit. For a restricted class of two-body interactions, we obtain convergence estimates uniform in the Planck constant , up to an exponentially small remainder. For h=0, the classical dynamics in the mean-field limit is given by the Vlasov equation.Comment: Latex 2e, 18 page

Control and stabilization for the wave equation in an expanding domain

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The analytic structure of 2D Euler flow at short times

Using a very high precision spectral calculation applied to the incompressible and inviscid flow with initial condition $\psi_0(x_1, x_2) = \cos x_1+\cos 2x_2$, we find that the width $\delta(t)$ of its analyticity strip follows a $\ln(1/t)$ law at short times over eight decades. The asymptotic equation governing the structure of spatial complex-space singularities at short times (Frisch, Matsumoto and Bec 2003, J.Stat.Phys. 113, 761--781) is solved by a high-precision expansion method. Strong numerical evidence is obtained that singularities have infinite vorticity and lie on a complex manifold which is constructed explicitly as an envelope of analyticity disks.Comment: 19 pages, 14 figures, published versio

Ideal evolution of MHD turbulence when imposing Taylor-Green symmetries

We investigate the ideal and incompressible magnetohydrodynamic (MHD) equations in three space dimensions for the development of potentially singular structures. The methodology consists in implementing the four-fold symmetries of the Taylor-Green vortex generalized to MHD, leading to substantial computer time and memory savings at a given resolution; we also use a re-gridding method that allows for lower-resolution runs at early times, with no loss of spectral accuracy. One magnetic configuration is examined at an equivalent resolution of $6144^3$ points, and three different configurations on grids of $4096^3$ points. At the highest resolution, two different current and vorticity sheet systems are found to collide, producing two successive accelerations in the development of small scales. At the latest time, a convergence of magnetic field lines to the location of maximum current is probably leading locally to a strong bending and directional variability of such lines. A novel analytical method, based on sharp analysis inequalities, is used to assess the validity of the finite-time singularity scenario. This method allows one to rule out spurious singularities by evaluating the rate at which the logarithmic decrement of the analyticity-strip method goes to zero. The result is that the finite-time singularity scenario cannot be ruled out, and the singularity time could be somewhere between $t=2.33$ and $t=2.70.$ More robust conclusions will require higher resolution runs and grid-point interpolation measurements of maximum current and vorticity.Comment: 18 pages, 13 figures, 2 tables; submitted to Physical Review

Relative entropy and the stability of shocks and contact discontinuities for systems of conservation laws with non BV perturbations

We develop a theory based on relative entropy to show the uniqueness and L^2 stability (up to a translation) of extremal entropic Rankine-Hugoniot discontinuities for systems of conservation laws (typically 1-shocks, n-shocks, 1-contact discontinuities and n-contact discontinuities of large amplitude) among bounded entropic weak solutions having an additional trace property. The existence of a convex entropy is needed. No BV estimate is needed on the weak solutions considered. The theory holds without smallness condition. The assumptions are quite general. For instance, strict hyperbolicity is not needed globally. For fluid mechanics, the theory handles solutions with vacuum.Comment: 29 page

Determinants of The Fear of The Pandemic and Its Effect on Voting Behavior Among Young Adult Filipinos in The Next Presidential Election

With COVID-19 severely impacting several aspects of society, the upcoming 2022 Philippine Presidential Elections will be the first to take place under such unique circumstances. This study provides information on how various determinants of fear of COVID-19 affect the voting behavior of young adult Filipinos. This study utilized a survey consisting of five sections composed of sociodemographic questionnaire, Multidimensional Scale of Perceived Social Support, Core Dimensions of Spirituality Questionnaire, Fear of COVID-19 Scale and a question about political participation. The results showed that individuals with a higher level of social support and higher level of spirituality were more likely to conform to the political ideals of their respective environments (i.e. family & religious institutions) and were more likely to participate in the elections, along with individuals with higher levels of fea

Quasivariational solutions for first order quasilinear equations with gradient constraint

We prove the existence of solutions for an evolution quasi-variational inequality with a first order quasilinear operator and a variable convex set, which is characterized by a constraint on the absolute value of the gradient that depends on the solution itself. The only required assumption on the nonlinearity of this constraint is its continuity and positivity. The method relies on an appropriate parabolic regularization and suitable {\em a priori} estimates. We obtain also the existence of stationary solutions, by studying the asymptotic behaviour in time. In the variational case, corresponding to a constraint independent of the solution, we also give uniqueness results

The Hartree limit of Born's ensemble for the ground state of a bosonic atom or ion

The non-relativistic bosonic ground state is studied for quantum N-body systems with Coulomb interactions, modeling atoms or ions made of N "bosonic point electrons" bound to an atomic point nucleus of Z "electron" charges, treated in Born--Oppenheimer approximation. It is shown that the (negative) ground state energy E(Z,N) yields the monotonically growing function (E(l N,N) over N cubed). By adapting an argument of Hogreve, it is shown that its limit as N to infinity for l > l* is governed by Hartree theory, with the rescaled bosonic ground state wave function factoring into an infinite product of identical one-body wave functions determined by the Hartree equation. The proof resembles the construction of the thermodynamic mean-field limit of the classical ensembles with thermodynamically unstable interactions, except that here the ensemble is Born's, with the absolute square of the ground state wave function as ensemble probability density function, with the Fisher information functional in the variational principle for Born's ensemble playing the role of the negative of the Gibbs entropy functional in the free-energy variational principle for the classical petit-canonical configurational ensemble.Comment: Corrected version. Accepted for publication in Journal of Mathematical Physic

Internal Anisotropy of Collision Cascades

We investigate the internal anisotropy of collision cascades arising from the branching structure. We show that the global fractal dimension cannot give an adequate description of the geometrical structure of cascades because it is insensitive to the internal anisotropy. In order to give a more elaborate description we introduce an angular correlation function, which takes into account the direction of the local growth of the branches of the cascades. It is demonstrated that the angular correlation function gives a quantitative description of the directionality and the interrelation of branches. The power law decay of the angular correlation is evidenced and characterized by an exponent and an angular correlation length different from the radius of gyration. It is demonstrated that the overlapping of subcascades has a strong effect on the angular correlation.Comment: RevteX, 8 pages, 6 .eps figures include