Effects of channel estimation on multiuser virtual MIMO-OFDMA relay-based networks

In this paper, a practical multi-user cooperative transmission scheme denoted as Virtual Maximum Ratio Transmission (VMRT) for Multiple-Input Multiple-Output - Orthogonal Frequency Division Multiple Access (MIMO-OFDMA) Relay-based networks is proposed and evaluated in the presence of a realistic channel estimation algorithm. It is shown that this scheme is robust against channel estimation errors and offers diversity and array gain keeping the complexity low, although the multi-user and multi-antenna channel estimation algorithm is simple and efficient. Diversity gains larger than 4 can be easily obtained with reduced number of relays. Thus, this scheme can be used to extend coverage or increase system throughput by using simple cooperative OFDMA-based relays

Effects of channel estimation on multiuser virtual MIMO-OFDMA relay-based networks

In this paper, a practical multi-user cooperative transmission scheme denoted as Virtual Maximum Ratio Transmission (VMRT) for Multiple-Input Multiple-Output - Orthogonal Frequency Division Multiple Access (MIMO-OFDMA) Relay-based networks is proposed and evaluated in the presence of a realistic channel estimation algorithm. It is shown that this scheme is robust against channel estimation errors and offers diversity and array gain keeping the complexity low, although the multi-user and multi-antenna channel estimation algorithm is simple and efficient. Diversity gains larger than 4 can be easily obtained with reduced number of relays. Thus, this scheme can be used to extend coverage or increase system throughput by using simple cooperative OFDMA-based relays

Effects of channel estimation on multiuser virtual MIMO-OFDMA relay-based networks

In this paper, a practical multi-user cooperative transmission scheme denoted as Virtual Maximum Ratio Transmission (VMRT) for Multiple-Input Multiple-Output - Orthogonal Frequency Division Multiple Access (MIMO-OFDMA) Relay-based networks is proposed and evaluated in the presence of a realistic channel estimation algorithm. It is shown that this scheme is robust against channel estimation errors and offers diversity and array gain keeping the complexity low, although the multi-user and multi-antenna channel estimation algorithm is simple and efficient. Diversity gains larger than 4 can be easily obtained with reduced number of relays. Thus, this scheme can be used to extend coverage or increase system throughput by using simple cooperative OFDMA-based relays

A new calculation method for the temperature of the components of composite slabs under fire

Composite steel-concrete slabs are structural elements composed of a profiled steel deck which acts as a permanent formwork to the concrete topping. This layer is commonly reinforced with individual rebars and an anti-crack mesh. The Annex D of the EN 1994-1-2 provides guidelines for the calculation of the temperature of the steel components of composite slabs subjected to the standard fire. However, no revisions were made to these calculation rules during the last years. This paper proposes a new method for the estimation of the temperature of the parts of the steel deck and the rebars as well. The proposed methodology is derived from numerical analyses using a 3-D finite element model, considering perfect thermal contact between the materials.info:eu-repo/semantics/publishedVersio

An event in the iberoamerican cooperation for the conservation and utilization of the zoogenetic resources

Between 1st and 4th of December, 2003; an event was celebrated in the city of Recife (Pernambuco, Brazil) congregating more than 200 researchers of 16 countries, to present results and discuss the last advances in the Iberoamerican Zoogenetics Resources Conservation and Utilization Area, taking into account contents over Genetics, Assisted reproduction, Rural development and Ethnology. In the present editorial a slight introduction is developed to locate the reader in the objectives, the contents and the development of the event, standing out the rule developed by the organizers, the supporters and the contributors.Del uno al cuatro de diciembre de 2003 se celebró en la ciudad de Recife (Pernambuco, Brasil) un evento que congregó a más de 200 investigadores de 16 países, para presentar resultados y discutir los últimos avances en el área de la conservación y utilización de los Recursos Zoogenéticos de Iberoamérica, tratándose contenidos sobre Genética, Reproducción asistida, Desarrollo rural, y Etnología principalmente. En la presente editorial se realiza una somera introducción para ubicar al lector en los objetivos, los contenidos y el desarrollo del evento, resaltando el papel desarrollado por los organizadores, patrocinadores y participantes

Designing a Novel System for the Introduction of Lubricant in Control Cables for the Automotive Industry

The increasing competitiveness installed in the automotive industry implies continuous improvements in all fields of knowledge and action. Thus, it is very important to be aware of the wastes generate across all the productive and logistics operations. In this regard, and considering the production process of command cables for the automotive industry, it was detected that a significant volume of lubricant is wasted during the task of introducing grease into the spiral used in the command cables utilized to drive the doors, windows and brakes of motor vehicles. The industrial operation was carefully followed leading to identify the main causes of the wastes and a brainstorming was carried out allowing the discussion of new ideas on how to overcome the problem. A novel equipment was developed, being also cared all the logistics around the supplying task. The new solution developed, as well as the redefinition of the logistic process of supplying the lubricating grease to the production lines, made it possible to make the process more flexible for the admission of different grease packs, as well as a better utilization of the existing grease in the reservoirs, resulting in a cut of grease waste by more than 70%. It was also produced a prototype of the grease supply system, which allowed validate the previously developed system.info:eu-repo/semantics/publishedVersio

Phosphorus removal by a fixed-bed hybrid polymer nanocomposite biofilm reactor

Eutrophication is one of the main challenges regarding the ecological quality of surface waters, phosphorus bioavailability being its main driver. In this context, a novel hybrid polymer nanocomposite (HPN-Pr) biofilm reactor aimed at integrated chemical phosphorus adsorption and biological removal was conceived. The assays pointed to removal of 1.2 mg P/g of reactive phosphorus and 1.01 mg P/g of total phosphorus under steady-state conditions. A mathematical adsorption–biological model was applied to predict reactor performance, which indicated that biological activity has a positive effect on reactor performance, increasing the amount of reactive phosphorus removed.The authors acknowledge the Portuguese Foundation for Science and Technology for the financial support under Project SFRH/BD/39085/2007

Erratum To: Quality Of Sweat Test (st) Based On The Proportion Of Sweat Sodium (na) And Sweat Chloride (cl) As Diagnostic Parameter Of Cystic Fibrosis: Are We On The Right Way?

During production of the original article [1] the Methods section included an incorrect sentence. The following sentence "For the analysis of variables with numerical distribution, Fisher's exact test and one-way analysis of variance were used" should be corrected as "For the analysis of variables with numerical distribution, Student's t-test and one-way analysis of variance were used". © The Author(s).12

A biphotons double slit experiment

In this paper we present a double slit experiment where two undistinguishable photons produced by type I PDC are sent each to a well defined slit. Data about the diffraction and interference patterns for coincidences are presented and discussed. An analysis of these data allows a first test of standard quantum mechanics against de Broglie-Bohm theory