The scattering map in two coupled piecewise-smooth systems, with numerical application to rocking blocks

We consider a non-autonomous dynamical system formed by coupling two piecewise-smooth systems in \RR^2 through a non-autonomous periodic perturbation. We study the dynamics around one of the heteroclinic orbits of one of the piecewise-smooth systems. In the unperturbed case, the system possesses two $C^0$ normally hyperbolic invariant manifolds of dimension two with a couple of three dimensional heteroclinic manifolds between them. These heteroclinic manifolds are foliated by heteroclinic connections between $C^0$ tori located at the same energy levels. By means of the {\em impact map} we prove the persistence of these objects under perturbation. In addition, we provide sufficient conditions of the existence of transversal heteroclinic intersections through the existence of simple zeros of Melnikov-like functions. The heteroclinic manifolds allow us to define the {\em scattering map}, which links asymptotic dynamics in the invariant manifolds through heteroclinic connections. First order properties of this map provide sufficient conditions for the asymptotic dynamics to be located in different energy levels in the perturbed invariant manifolds. Hence we have an essential tool for the construction of a heteroclinic skeleton which, when followed, can lead to the existence of Arnol'd diffusion: trajectories that, on large time scales, destabilize the system by further accumulating energy. We validate all the theoretical results with detailed numerical computations of a mechanical system with impacts, formed by the linkage of two rocking blocks with a spring

Widening the focus on informal entrepreneurship through the lens of intersectionality

The article explores the struggle of those involve with the entrepreneurial activities in the informal economy, within the challenging socio-economic environments. It investigates the extent to which intersectionality through structural, disciplinary, hegemonic and interpersonal power associated with poor, marginalised groups influence their entrepreneurial actions and rights collectively. Studies either view entrepreneurs through an informality lens, as marginalised populations engaged in low‐quality activities, or through a formality lens, as engaged in relatively higher quality entrepreneurial activities more as a necessity choice. The aim of this paper is to evaluate critically these explanations through intersectionality power in relation to waste pickers entrepreneurs in the informal sector in Colombia

"Fitting in" vs "standing out": How Social Enterprises Engage with Stakeholders to Legitimise their Hybrid Position

We investigate how social enterprises actively engage with their stakeholders to legitimise their hybrid position in addressing both social and businesses audience. This is particularly important in their effort to capturing stability (expectation to ‘fit in’) within an emerging field and at the same time to address change and growth (expectation to ‘stand out’) with their limited resources, in order to be profitable enterprises, while creating social value. We analyse in-depth interviews to senior members of twenty-one UK-based social enterprises, and we find that for many SEs involved in legitimisation exercise through the supportive system, collective system, and stakeholders' impression. By outlining the integrated framework on stakeholder engagement for hybrid legitimacy, we found that (i) legitimisation exercise through collective sharing of SE identity help to build SE image and legitimise SE socially driven mission, while (ii) legitimisation through supportive system (resources and business advantage) help building credibility by demonstrating SE capability to grow economically

Mean-Reverting Stochastic Processes, Evaluation of Forward Prices and Interest Rates

We consider mean-reverting stochastic processes and build self-consistent models for forward price dynamics and some applications in power industries. These models are built using the ideas and equations of stochastic differential geometry in order to close the system of equations for the forward prices and their volatility. Some analytical solutions are presented in the one factor case and for specific regular forward price/interest rates volatility. Those models will also play a role of initial conditions for a stochastic process describing forward price and interest rates volatility. Subsequently, the curved manifold of the internal space i.e. a discrete version of the bond term space (the space of bond maturing) is constructed. The dynamics of the point of this internal space that correspond to a portfolio of different bonds is studied. The analysis of the discount bond forward rate dynamics, for which we employed the Stratonovich approach, permitted us to calculate analytically the regular and the stochastic volatilities. We compare our results with those known from the literature.: Stochastic Differential Geometry, Mean-Reverting Stochastic Processes and Term Structure of Specific (Some) Economic/Finance Instruments

Quantifying Flexibility Real Options Calculus

We expose a real options theory as a tool for quantifying the value of the operating flexibility of real assets. Additionally, we have pointed out that this theory is an appropriated methodology for determining optimal operating policies, and provide an example of successful application of our approach to power industries, specifically to valuate the power plant of electricity. In particular by increasing the volatility of prices will eventually lead to higher assets values.real options, Black-Scholes Approach, Wiener processes, stochastic processes, Quantifying Flexibility, volatility

A polynomial rooting approach for synchronization in multipath channels using antenna arrays

The estimation of the delay of a known training signal received by an antenna array in a multipath channel is addressed. The effect of the co-channel interference is taken into account by including a term with unknown spatial correlation. The channel is modeled as an unstructured FIR filter. The exact maximum likelihood (ML) solution for this problem is derived, but it does not have a simple dependence on the delay. An approximate estimator that is asymptotically equivalent to the exact one is presented. Using an appropriate reparameterization, it is shown that the delay estimate is obtained by rooting a low-order polynomial, which may be of interest in applications where fast feedforward synchronization is needed.Peer ReviewedPostprint (published version

The Prenegotiation Phase on International Trade in Services Negotiations: A Case Study on North/South Issues Negotiations

Only after four years of prenegotiations did the Uruguay Round of Multilateral Trade Negotiations take place in 1986. This paper analyzes the prenegotiation phase on international trade in services by focusing on a North-South perspective of the underlying economics of international trade in services and the diplomatic exercise this prenegotiation phase set off. The factors during the prenegotiation phase which led to the launch of the Uruguay Round of negotiations are dissected as well as how the prenegotiation phase weakened the GATT’s long standing positive reputation. An overview of the important economic issues which will influence the General Agreement on Trade in Services (GATS) is included

A comparison of hot and cold processing of pork for fresh, cured and smoked, and emulsified meat products

Cured hams and bellies, vacuum packaged fresh pork loins, and emulsion type sausages (bologna) were processed using cold (conventional) and hot processing. Fresh cut yields, cooking losses (hams, bellies, sausages), pH, water holding capacity, emulsion capacity, tenderness (loin chops), purge (loin roasts), distortion (bellies), color (fresh pork loin), juiciness and flavor (bologna) were compared to determine the effect of the two treatments on these physical and sensory properties. There were no significant differences in fresh cut yields, cooking losses, water holding capacity, emulsion capacity, tenderness, purge, color, fresh and cured belly areas, or bologna juiciness and flavor. But, hot processed carcasses had lower belly and sausage cooking losses, shear values, and purge, and higher water holding capacity, and emulsion capacity than the cold processed carcasses. Hot processed carcasses had significantly higher pH (P\u3c0.05), wider fresh and cured bellies (P\u3c0.01) than cold processed carcasses. Fresh and cured cold processed bellies were longer (P\u3c0.01) than the hot processed carcasses