A Statistical Analysis of Multipath Interference for Impulse Radio UWB Systems

In this paper, we develop a statistical characterization of the multipath interference in an Impulse Radio (IR)-UWB system, considering the standardized IEEE 802.15.4a channel model. In such systems, the chip length has to be carefully tuned as all the propagation paths located beyond this limit can cause interframe/intersymbol interferences (IFI/ISI). Our approach aims at computing the probability density function (PDF) of the power of all multipath components with delays larger than the chip time, so as to prevent such interferences. Exact analytical expressions are derived first for the probability that the chip length falls into a particular cluster of the multipath propagation model and for the statistics of the number of paths spread over several contiguous clusters. A power delay profile (PDP) approximation is then used to evaluate the total interference power as the problem appears to be mathematically intractable. Using the proposed closed-form expressions, and assuming minimal prior information on the channel state, a rapid update of the chip time value is enabled so as to control the signal to interference plus noise ratio.Comment: 17 pages, 9 figures; submitted to the Journal of the Franklin Institute on Sept. 24, 201

Momentum-sector-selective metal-insulator transition in the eight-site dynamical mean-field approximation to the Hubbard model in two dimensions

We explore the momentum-sector-selective metal insulator transitions recently found in the eight - site dynamical cluster approximation to the two-dimensional Hubbard model. The phase diagram in the space of interaction and second-neighbor hopping is established. The initial transitions from Fermi-liquid like to sector-selective phases are found to be of second order, caused by the continuous opening of an energy gap whereas the other transitions are found to be of first order. In the sector-selective phase the Fermi surface regions which are not gapped are found to have a non-Fermi-liquid self-energy. We demonstrate that the phenomenon is not caused by the Van Hove divergence in the density of states. The sector-selective and insulating phases are characterized by a cluster spin correlation function that is strongly peaked at the commensurate antiferromagnetic wave vector $(\pi,\pi)$ but the model has no nematic instability. Comparison to dynamical mean-field studies on smaller clusters is made

Floristic composition of Azorean littoral rock pools.

43rd European Marine Biology Symposium”. Ponta Delgada, Açores, 8-12 de Setembro de 2008

Intergenerational correlations in size at birth and the contribution of environmental factors: The Uppsala Birth Cohort Multigenerational Study, Sweden, 1915-2002.

Sizes at birth of parents and their children are known to be correlated, reflecting in part the influence of fetal and maternal genes. Sociodemographic factors, regarded as aspects of the shared environment across generations, would also be expected to contribute, but evidence is limited. In the present study, the authors aimed to quantify the role of the shared environment in explaining intergenerational correlations in birth weight and length by using data across 3 consecutive generations from the Uppsala Birth Cohort Multigenerational Study in Uppsala, Sweden. That study included birth and sociodemographic data on 7,657 singletons born in Uppsala in 1915-1929 (generation 1) and their grandchildren (generation 3). Standard regression and biometric models were used to study the correlations in size at birth of generation 1-generation 3 pairs. The data showed stronger correlations in maternal pairs than in paternal pairs for birth weight (0.125 vs. 0.096, P = 0.02) but not for birth length (0.097 vs. 0.093, P = 0.77). These correlations were not reduced by adjustment for sociodemographic factors in regression models. In contrast, significant shared-environment contributions to the intergenerational correlations were identified in biometric models, averaging 14% for both birth measures. These models assumed a common latent factor for the sociodemographic variables. The present results show that the shared environment moderately but significantly contributes to intergenerational correlations

Computational tools for strain optimization by tuning the optimal level of gene expression

In this work, a plug-in for the OptFlux Metabolic Engineering platform is presented, implementing methods that allow the identification of sets of genes to over/under express, relatively to their wild type levels. The optimization methods used are Simulated Annealing and Evolutionary Algorithms, working with a novel representation and operators. This overcomes the limitations of previous approaches based solely on gene knockouts, bringing new avenues for Biotechnology, fostering the discovery of genetic manipulations able to increase the production of certain compounds using a host microbe. The plug-in is made freely available together with appropriate documentation.Support of FCT and Programa COMPETE (ref. PTDC/EIA-EIA/ 115176/2009)

Enhancing Teaching & Learning of Software Engineering in an International Environment

A fundamental artifact of any academic research isthe data used as the basis of that research effort. A group ofresearchers, from institutions in multiple territories, hasembarked on an ambitious research project that is initially aimedat enhancing the teaching of software engineering for four-yearundergraduate programs. The research project details a set ofworkshops, for which the objective is the capture of data that willbe the basis of the research effort. The first of these workshopswas held in August of 2011, and is reported on in this paper. Theworkshop comprised software engineering educators andrepresentatives from the information technology industry. Thedata collection task sought to identify a set of topics that areconsidered suitable for teaching software engineering, along withidentification of the years and depth at which these topics shouldbe taught. The use of technology in the curriculum design processis seen as an important step forward and this issue is alsodiscussed

Unitary representations of rational Cherednik algebras and Hecke algebras

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 49-50).We begin the study of unitary representations in the lowest weight category of rational Cherednik algebras of complex reflection groups. We provide the complete classification of unitary representations for the symmetric group, the dihedral group, as well as some additional partial results. We also study the unitary representations of Hecke algebras of complex reflection groups and provide a complete classification in the case of the symmetric group. We conclude that the KZ functor defined in [16] preserves unitarity in type A. Finally, we formulate a few conjectures concerning the classification of unitary representations for other types and the preservation of unitarity by the KZ functor and the restriction functors defined in [2].by Emanuel Stoica.Ph.D

Wewenang Pemerintah dalam Pembubaran Organisasi Masyarakat

Civil Society Organization (CSO) is an organization founded and formed by the community voluntarily based on the similarity of aspirations, wills, needs, interests and objectives to participate in development in order to achieve the objectives of the Unitary State of the Republic of Indonesia (NKRI). But many established organizations are not based on the common vision and mission required by the government. The emergence of a number of radical organizations that perform anarchist actions make people feel uneasy about the actions of mass organizations that commit acts of violence by using the pretext of religion as a justification reason. The Government in this case has considerable authority in Law No. 17 of 2013 on Civil Society Organizations where the ultimate estuary is the revocation of registered certificate which affects the dissolution of problematic community organizations. With the authority granted to the government, it is suggested that the government should be able to crack down on mass organizations which generate problematic causes and break public orders. Keywords: Government Power, Dissolution Of Civil Society Organization, Right to Associatio