Chapter Machine Learning Techniques to Mitigate Nonlinear Phase Noise in Moderate Baud Rate Optical Communication Systems

Nonlinear phase noise (NLPN) is the most common impairment that degrades the performance of radio-over-fiber networks. The effect of NLPN in the constellation diagram consists of a shape distortion of symbols that increases the symbol error rate due to symbol overlapping when using a conventional demodulation grid. Symbol shape characterization was obtained experimentally at a moderate baud rate (250 MBd) for constellations impaired by phase noise due to a mismatch between the optical carrier and the transmitted radio frequency signal. Machine learning algorithms have become a powerful tool to perform monitoring and to identify and mitigate distortions introduced in both the electrical and optical domains. Clustering-based demodulation assisted with Voronoi contours enables the definition of non-Gaussian boundaries to provide flexible demodulation of 16-QAM and 4+12 PSK modulation formats. Phase-offset and in-phase and quadrature imbalance may be detected on the received constellation and compensated by applying thresholding boundaries obtained from impairment characterization through statistical analysis. Experimental results show increased tolerance to the optical signal-to-noise ratio (OSNR) obtained from clustering methods based on k-means and fuzzy c-means Gustafson-Kessel algorithms. Improvements of 3.2 dB for 16-QAM, and 1.4 dB for 4+12 PSK in the OSNR scale as a function of the bit error rate are obtained without requiring additional compensation algorithms

Dominant Folding Pathways of a WW Domain

We investigate the folding mechanism of the WW domain Fip35 using a realistic atomistic force field by applying the Dominant Reaction Pathways (DRP) approach. We find evidence for the existence of two folding pathways, which differ by the order of formation of the two hairpins. This result is consistent with the analysis of the experimental data on the folding kinetics of WW domains and with the results obtained from large-scale molecular dynamics (MD) simulations of this system. Free-energy calculations performed in two coarse-grained models support the robustness of our results and suggest that the qualitative structure of the dominant paths are mostly shaped by the native interactions. Computing a folding trajectory in atomistic detail only required about one hour on 48 CPU's. The gain in computational efficiency opens the door to a systematic investigation of the folding pathways of a large number of globular proteins

Plan de negocios para una empresa dedicada al servicio de intermediaci?n entre conductores y pasajeros de servicio de transporte p?blico individual (taxi) a trav?s de una plataforma tecnol?gica : aplicaci?n movil para smartphone

El presente plan de negocio consiste en la prestaci?n de servicio de intermediaci?n entre conductores y pasajeros de servicio de transporte p?blico individual (taxi) a trav?s de una plataforma tecnol?gica (aplicaci?n m?vil para smartphone), teniendo en consideraci?n adicionar a partir del segundo a?o el servicio de publicidad e investigaci?n de mercado, dirigido a las empresas anunciantes y a las que a?n no anuncian, utilizando como herramienta las unidades de transporte de servicio p?blico individual (taxis). Estas unidades ser?n adecuadas para el fin del modelo de negocio adicional. El modelo de negocio propone un portafolio de opciones como publicidad a trav?s de pantallas t?ctiles al interior del veh?culo, publicidad en la luna posterior del veh?culo mediante viniles removibles, aplicaci?n de encuestas y prueba de productos durante el trayecto de viaje del usuario y publicidad mediante folletos. El modelo de negocio adicional se basar? en alianzas estrat?gicas con agencias de publicidad, las cuales ofrecer?n dentro de su abanico de opciones los servicios mencionados a sus clientes. Por otro lado, el servicio de intermediaci?n se realizar? mediante una aplicaci?n m?vil que se descargar? f?cilmente en los dispositivos m?viles, las comisiones que se pagar?n a los conductores ser?n las m?s bajas del mercado permiti?ndoles obtener mayores ganancias por cada servicio, y cuyas tarifas ser?n atractivas para el mercado. El principal ingreso provendr? del servicio de intermediaci?n de taxi ya que representa el 90% de ingresos y el servicio de publicidad e investigaci?n solo el 10%

Dise?o, procura, construcci?n y puesta en marcha de la ampliaci?n del taller de mantenimiento - fase A

El proyecto de ?Dise?o, procura, construcci?n y puesta en marcha de taller de mantenimiento Fase A?, considera incrementar la flota de camiones de 80 a 120 para el a?o 2025, y como consecuencia, la capacidad del actual taller de mantenimiento quedar? subdimensionada; siendo necesario ampliar sus instalaciones para garantizar la confiabilidad y disponibilidad mec?nica de los camiones mineros. Incluye el desarrollo de ingenier?a b?sica, ingenier?a de detalle, contrataciones, adquisici?n de equipos, suministro de materiales, construcci?n y puesta en marcha de la ampliaci?n del taller de mantenimiento que brinden servicio a los equipos de la flota minera. El alcance del trabajo incluye la ejecuci?n de trabajos tempranos en el patio de rescate y en la plataforma principal del taller, construcci?n de construcci?n de plataformas y accesos, desmontaje de instalaciones existentes, construcci?n de 7 bah?as de mantenimiento de camiones, infraestructura auxiliar, instalaci?n de redes de servicio, precomisionamiento y cominsionamiento. Para una adecuada ejecuci?n y entrega del proyecto, se desarrollan los planes de gesti?n de proyectos siguiendo los lineamientos de la gu?a est?ndar del PMBOK y 6ta. Edici?n, los cuales describen la metodolog?a, actividades y consideraciones que deber? tener el equipo para la gesti?n exitosa de este proyect

Quantum Pair Creation of Soliton Domain Walls

A large body of experimental evidence suggests that the decay of the false vacuum, accompanied by quantum pair creation of soliton domain walls, can occur in a variety of condensed matter systems. Examples include nucleation of charge soliton pairs in density waves [eg. J. H. Miller, Jr. et al., Phys. Rev. Lett. 84, 1555 (2000)] and flux soliton pairs in long Josephon junctions. Recently, Dias and Lemos [J. Math. Phys. 42, 3292 (2001)] have argued that the mass $m$ of the soliton should be interpreted as a line density and a surface density, respectively, for (2+1)-D and (3+1)-D systems in the expression for the pair production rate. As the transverse dimensions are increased and the total mass (energy) becomes large, thermal activation becomes suppressed, so quantum processes can dominate even at relatively high temperatures. This paper will discuss both experimental evidence and theoretical arguments for the existence of high-temperature collective quantum phenomena

Industrial Policies in Colombia

This paper surveys and analyzes industrial policies in Colombia, finding extensive use of productive development policies (PDPs) and despite claims of only moderate government intervention. Rarely explicitly associated with the need to address market failures, PDPs are instead associated with economic reactivation and vaguely defined competitiveness. There are also PDPs that address government failures considered unlikely to be corrected by first-best interventions. Colombia has made progress, however, in structuring an institutional setting for PDP design that is sufficiently linked with private sector groups to elicit information on constraints and opportunities that require government intervention. Nonetheless, the overall set of PDPs in place still lacks coherence and is not always guided by the policy requests of the private sector more widely defined

The Presidency and the Executive Branch in Latin America: What We Know and What We Need to Know

The presidential politics literature depicts presidents either as all- powerful actors or figureheads and seeks to explain outcomes accordingly. Th e president and the executive branch are nonetheless usually treated as black boxes, particularly i n developing countries, even though the presidency has evolved into an extremely complex branch of government. While these developments have been studied in the U nited States, far less i s known in other countries, particularly in Latin America, where presi dential systems have been considered the source of all goods and evils. To help close the knowledge gap and explore differences in policymaking characteristics not only between Latin America and the US but also across Latin American countries, this paper s ummarizes the vast literature on the organization and resources of the Executive Branch in the Americas and sets a research agenda for the study of Latin American presidencies.Fil: Bonvecchi, Alejandro. Universidad Torcuato Di Tella. Departamento de Ciencia Política y Estudios Internacionales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scartascini, Juan Carlos. Banco Interamericano de Desarrollo; Estados Unido