Partial-Data Superimposed Training with Data Precoding for OFDM Systems

Superimposed training (ST) is a recently addressed technique used for channel estimation where known training sequences are arithmetically added to data symbols, avoiding the use of dedicated pilot subcarriers, and thus, increasing the available bandwidth compared with traditional pilot symbol assisted modulation schemes. However, the system handles data interference over channel estimation as a result of the ST process; also, data detection is degraded by pilot interference. Recent ST methods have analyzed the data interference and presented schemes that deal with it. We propose a novel superimposed model over a precoded data scheme, named partial-data superimposed training (PDST), where an interference control factor assigns the adequate information level to be added to the training sequence in orthogonal frequency division multiplexing systems. Also, a data detection method is introduced to improve the symbol error rate performance. Moreover, a capacity analysis of the system has been derived. Finally, simulation results confirm that performance of PDST is superior to previous proposals

Satisfacción laboral en asesores telefónicos de un call center del distrito de Surco, 2021

El presente estudio tuvo por objetivo determinar las diferencias significativas respecto a Satisfacción laboral según sexo en asesores telefónicos de un Call Center del distrito de Surco, 2021. El enfoque empleado es el cuantitativo, con un diseño no experimental, corte transversal y de tipo descriptivo comparativo. La muestra es de tipo censal y estuvo compuesta por 90 trabajadores, de ambos sexos; como instrumento para la recolección de datos se empleó, el Cuestionario de Satisfacción Laboral de Gosalvez (2019). Los resultados revelaron que no se evidencian diferencias significativas respecto a la Satisfacción laboral según el sexo de los asesores telefónicos p=958 (p>.05) y en cuanto a los factores de la Satisfacción Laboral evaluados, se obtuvo que en Desarrollo Profesional p=.780 (p>.05) no se evidencia diferencias significativas respecto al sexo del asesor, mientras que Clima Organizacional p=.040 (p<.05) y Condiciones Laborales p=.031 (p<.05) se evidencian diferencias significativas según el sexo, donde resultan que las mujeres están más satisfechas que los hombre

Background, Systematic Review, Challenges and Outlook

Publisher Copyright: © 2013 IEEE. This research is supported by the Digital Manufacturing and Design Training Network (DiManD) project funded by the European Union through the Marie Skłodowska-Curie Innovative Training Networks (H2020-MSCA-ITN-2018) under grant agreement no. 814078The concept of smart manufacturing has attracted huge attention in the last years as an answer to the increasing complexity, heterogeneity, and dynamism of manufacturing ecosystems. This vision embraces the notion of autonomous and self-organized elements, capable of self-management and self-decision-making under a context-aware and intelligent infrastructure. While dealing with dynamic and uncertain environments, these solutions are also contributing to generating social impact and introducing sustainability into the industrial equation thanks to the development of task-specific resources that can be easily adapted, re-used, and shared. A lot of research under the context of self-organization in smart manufacturing has been produced in the last decade considering different methodologies and developed under different contexts. Most of these works are still in the conceptual or experimental stage and have been developed under different application scenarios. Thus, it is necessary to evaluate their design principles and potentiate their results. The objective of this paper is threefold. First, to introduce the main ideas behind self-organization in smart manufacturing. Then, through a systematic literature review, describe the current status in terms of technological and implementation details, mechanisms used, and some of the potential future research directions. Finally, the presentation of an outlook that summarizes the main results of this work and their interrelation to facilitate the development of self-organized manufacturing solutions. By providing a holistic overview of the field, we expect that this work can be used by academics and practitioners as a guide to generate awareness of possible requirements, industrial challenges, and opportunities that future self-organizing solutions can have towards a smart manufacturing transition.publishersversionpublishe

Vulnerabilidades de seguridad en el servicio de internet de banda ancha en redes hfc: impacto y posibles soluciones

El servicio de Internet de banda ancha de las redes hibridas fibra-coaxial es vulnerable en la actualidad en nuestro país debido a diferentes métodos de acceso no autorizado al servicio; con este trabajo se analizarán los problemas de seguridad de estas redes. Se realizara una revisión de los métodos de acceso no autorizado al servicio y proporcionaremos diversas soluciones para prevenir y evitar estos problemas de seguridad, mejorando el control sobre el servicio prestado al cliente, incrementando la disponibilidad de ancho de banda al usuario que paga por dicho servicio, y permitiendo al proveedor ofrecer el servicio a más clientes así como una mejoría en su calidad del servicio En la actualidad está muy difundido en todo el mundo el acceso a Internet de banda ancha por medio de redes HFC siendo las vulnerabilidades de seguridad de este sistema por tanto un problema global. Por lo tanto la aplicación de las recomendaciones dada en esta investigación será de una magnifica ayuda para combatir el acceso no autorizado al servicio así como del uso indebido del mismo y su crecimiento

Enabling Technologies, Frameworks and Applications

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14-Angeloyloxycacalohastine from Psacalium peltatum

The title compound [systematic name: (9-meth­oxy-3,5-dimethyl-5,6-dihydro­naphtho­[2,3-b]furan-4-yl)methyl 2-meth­yl­but-2-enoate], C21H24O4, was isolated from matarique, or Psacalium peltatum (Kunth). The structure is almost planar. The angelo­yloxy group makes an angle of 62.08 (2)° with the furan­oeremophilane skeleton. The carbonyl O atom is disordered between two positions with a 76:24 ratio. The mol­ecules in the crystal are joined by very weak C—H—O inter­actions in the ac plane

A Measurement Study of Online Tracking and Advertising in Ibero-America

The ability of the online marketing industry to track and profile users’ Web-browsing activity is what enables effective, tailored-made advertising services. The intrusiveness of these practices and the increasing invasiveness of digital advertising, however, have raised serious concerns regarding user privacy. Although the level of ubiquity of tracking and advertising has been investigated in top-world sites based in North America and Western Europe, the extent to which those practices are carried out in territories with less or no legal coverage —in terms of data protection— has not been studied so far. In this work, we present the first detailed measurement of online tracking and advertising conducted to date in one of those regions, namely, Ibero-America, by analyzing local websites (e.g., education and government sites). In doing so, our measurement study aims to find out how user location as well as the type of publisher may impact on tracking and advertising and thus user privacy. Lastly, our thorough, extensive analysis also explores whether differences are appreciated between Latin America and the EU with regard to the third-party tracking conducted from and towards the corresponding countries

Parameter identification of periodical signals: Application to measurement and analysis of ocean wave forces

This article presents an approach based on state observers to identify the parameters of an unknown periodic force exerted on a mechanical system. This approach comprises two stages and can be executed in real time by using only displacement measurements. The first stage goal is the estimation of the coefficients of a Fourier series that approximates the periodic force. From the estimated coefficients, the phase and the amplitude of the signal can be simultaneously computed; and from the estimated force, in a second stage, the frequencies of the signal can be estimated. To perform the tasks at each stage, two state observers were designed. To show the applicability of the proposed approach, the reconstruction of a wave force affecting a marine structure as well as the computation of the amplitude and phase of its spectral components was taken as case of study. The performance of the state observer was examined by means of simulations and off-line tests carried out with experimental data. Such data were obtained by executing laboratory tests and measuring waves in the Caribbean sea