A model for companies to overcome US–China conflict on international trade

This article aims to study international trade specificity and the main activities of Chinese companies in US markets. It addresses the strategic tools of companies and their application in a global and very competitive market, framed by public policies and governments’ strategies. It explores the principles of the internal and external environment of the countries. The main research question is: what are the dimensions of a model to potentiate the US–China Companies? The principal methodology used in this research was a literature review, and the analysis was based on the papers that research the theme US and China trade relations. The findings reflect that international trade is conditioned by the government politics, and there are several other obstacles that a US or Chinese company need to overcome: (a) economic forces; (b) technological forces; (c) political–legal forces; (d) sociocultural forces; and (e) physical forces.info:eu-repo/semantics/publishedVersio

A simple deterministic self-organized critical system

We introduce a new continuous cellular automaton that presents self-organized criticality. It is one-dimensional, totally deterministic, without any kind of embedded randomness, not even in the initial conditions. This system is in the same universality class as the Oslo rice pile system, boundary driven interface depinning and the train model for earthquakes. Although the system is chaotic, in the thermodynamic limit chaos occurs only in a microscopic level.Comment: System slightly modified. New results on Liapunov exponents. Submitted for publication (8 pages

Spin filtering in nanowire directional coupler

The spin transport characteristics of a nanowire directional electronic coupler have been evaluated theoretically via a transfer matrix approach. The application of a gate field in the region of mixing allows for control of spin current through the different leads of the coupler via the Rashba spin-orbit interaction. The combination of spin-orbit interaction and applied gate voltages on different legs of the coupler give rise to a controllable modulation of the spin polarization. Both structural factors and field strength tuning lead to a rich phenomenology that could be exploited in spintronic devices.Comment: 9 pages, 4 figure

Two-dimensional quantum spin-1/2 Heisenberg model with competing interactions

We study the quantum spin-1/2 Heisenberg model in two dimensions, interacting through a nearest-neighbor antiferromagnetic exchange ($J$) and a ferromagnetic dipolar-like interaction ($J_d$), using double-time Green's function, decoupled within the random phase approximation (RPA). We obtain the dependence of $k_B T_c/J_d$ as a function of frustration parameter $\delta$, where $T_c$ is the ferromagnetic (F) transition temperature and $\delta$ is the ratio between the strengths of the exchange and dipolar interaction (i.e., $\delta = J/J_d$). The transition temperature between the F and paramagnetic phases decreases with $\delta$, as expected, but goes to zero at a finite value of this parameter, namely $\delta = \delta_c = \pi /8$. At T=0 (quantum phase transition), we analyze the critical parameter $\delta_c(p)$ for the general case of an exchange interaction in the form $J_{ij}=J_d/r_{ij}^{p}$, where ferromagnetic and antiferromagnetic phases are present.Comment: 4 pages, 1 figur

Mapping the educational and career paths of youth workers

info:eu-repo/semantics/publishedVersio