Information and communication in a networked infosphere: a review of concepts and application in social branding

This paper aims at providing a contribution to the comprehensive review of the impact of information and communication, and their supporting technologies, in the current transformation of human life in the infosphere. The paper also offers an ex- ample of the power of new social approaches to the use of information and commu- nication technologies to foster new working models in organizations by presenting the main outcomes of a research project on social branding. A discussion about some trends of the future impact of new information and communication technologies in the infosphere is also included

Dynamic whole-body motion generation under rigid contacts and other unilateral constraints

The most widely used technique for generating wholebody motions on a humanoid robot accounting for various tasks and constraints is inverse kinematics. Based on the task-function approach, this class of methods enables the coordination of robot movements to execute several tasks in parallel and account for the sensor feedback in real time, thanks to the low computation cost. To some extent, it also enables us to deal with some of the robot constraints (e.g., joint limits or visibility) and manage the quasi-static balance of the robot. In order to fully use the whole range of possible motions, this paper proposes extending the task-function approach to handle the full dynamics of the robot multibody along with any constraint written as equality or inequality of the state and control variables. The definition of multiple objectives is made possible by ordering them inside a strict hierarchy. Several models of contact with the environment can be implemented in the framework. We propose a reduced formulation of the multiple rigid planar contact that keeps a low computation cost. The efficiency of this approach is illustrated by presenting several multicontact dynamic motions in simulation and on the real HRP-2 robot

How triathletes mount their bikes after first transition (T1). A proposal of classification

A proposal is submit for the classification referring to the different ways in which triathletes mount their bikes to start pedalling. This action happens at the end of the transition area (T1) after having gone across on foot, with the bikes at their side, or, led across by hand, in a specific way (Fernández, Romero, Merino and April, 2015). These are unique aspects of this sport, compared to other sports in which a bike is also used. The purpose of this research was concentrates in describing and classifying the motor behaviours that occur at the end of the transition area, in front of the “judge’s line”. This study was bassed on participants of 3 Spanish Elite Championships of different distances (407 triathletes). It was filmed in the moment when they picked up their bikes, passed through the transition area and mounted their bikes. Eleven different ways were discovered on how to mount a bike when passing the judge’s line.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Inverse results for weighted Harborth constants

For a finite abelian group $(G,+)$ the Harborth constant is defined as the smallest integer $\ell$ such that each squarefree sequence over $G$ of length $\ell$ has a subsequence of length equal to the exponent of $G$ whose terms sum to $0$. The plus-minus weighted Harborth constant is defined in the same way except that the existence of a plus-minus weighted subsum equaling $0$ is required, that is, when forming the sum one can chose a sign for each term. The inverse problem associated to these constants is the problem of determining the structure of squarefree sequences of maximal length that do not yet have such a zero-subsum. We solve the inverse problems associated to these constant for certain groups, in particular for groups that are the direct sum of a cyclic group and a group of order two. Moreover, we obtain some results for the plus-minus weighted Erd\H{o}s--Ginzburg--Ziv constant

Optimized Cell Planning for Network Slicing in Heterogeneous Wireless Communication Networks

We propose a cell planning scheme to maximize the resource efficiency of a wireless communication network while considering quality-of-service requirements imposed by different mobile services. In dense and heterogeneous cellular 5G networks, the available time-frequency resources are orthogonally partitioned among different slices, which are serviced by the cells. The proposed scheme achieves a joint optimization of the resource distribution between network slices, the allocation of cells to operate on different slices, and the allocation of users to cells. Since the original problem formulation is computationally intractable, we propose a convex inner approximation. Simulations show that the proposed approach optimizes the resource efficiency and enables a service-centric network design paradigm.Comment: This article has been accepted for publication in a future issue of the IEEE Communications Letters, https://ieeexplore.ieee.org/document/8368293, (c) 2018 IEE

La agencia nacional de contratación: Unificación administrativa de la contratación pública colombiana

18 páginasEl área de contratación es una de las más activas dentro de la administración pública. En Colombia, mediante el decreto 4170 del 3 de noviembre de 2011 se creó la Agencia Nacional de Contratación, organismo gubernamental especializado, encargado de centralizar y administrar la contratación pública nacional. La ausencia de un control eficaz y especializado a sido factor de corrupción en la contratación de grandes proyectos de obra pública principalmente, lo que además de resentir los recursos púbicos ha retrasado el desarrollo infraestructura nacional. De otra parte, la legislación ha sido improvisada e inestable, problema relacionado a una ausencia de unidad institucional que ha impedido una gestión eficiente y económica para el estado contratante como para los particulares oferentes.Especialización en Contratación EstatalEspecialista en Contratación Estata

Complex dynamics in simple systems with seasonal parameter oscillations

We study systems with periodically oscillating parameters that can give way to complex periodic or non periodic orbits. Performing the long time limit, we can define ergodic averages such as Lyapunov exponents, where a negative maximal Lyapunov exponent corresponds to a stable periodic orbit. By this, extremely complicated periodic orbits composed of contracting and expanding phases appear in a natural way. Employing the technique of $\epsilon$-uncertain points, we find that values of the control parameters supporting such periodic motion are densely embedded in a set of values for which the motion is chaotic. When a tiny amount of noise is coupled to the system, dynamics with positive and with negative non-trivial Lyapunov exponents are indistinguishable. We discuss two physical systems, an oscillatory flow inside a duct and a dripping faucet with variable water supply, where such a mechanism seems to be responsible for a complicated alternation of laminar and turbulent phases.Comment: New version with major change

Constraints on Ho\u159ava gravity from binary black hole observations

Ho\u159ava gravity breaks Lorentz symmetry by introducing a preferred spacetime foliation, which is defined by a timelike dynamical scalar field, the khronon. The presence of this preferred foliation makes black hole solutions more complicated than in General Relativity, with the appearance of multiple distinct event horizons: a matter horizon for light/matter fields; a spin-0 horizon for the scalar excitations of the khronon; a spin-2 horizon for tensorial gravitational waves; and even, at least in spherical symmetry, a universal horizon for instantaneously propagating modes appearing in the ultraviolet. We study how black hole solutions in Ho\u159ava gravity change when the black hole is allowed to move with low velocity relative to the preferred foliation. These slowly moving solutions are a crucial ingredient to compute black hole "sensitivities" and predict gravitational wave emission (and, in particular, dipolar radiation) from the inspiral of binary black hole systems. We find that for generic values of the theory's three dimensionless coupling constants, slowly moving black holes present curvature singularities at the universal horizon. Singularities at the spin-0 horizon also arise unless one waives the requirement of asymptotic flatness at spatial infinity. Nevertheless, we have verified that at least in a one-dimensional subset of the (three-dimensional) parameter space of the theory's coupling constants, slowly moving black holes are regular everywhere, even though they coincide with the general-relativistic ones (thus implying, in particular, the absence of dipolar gravitational radiation). Remarkably, this subset of the parameter space essentially coincides with the one selected by the recent constraints from GW170817 and by solar system tests