On the distribution of an effective channel estimator for multi-cell massive MIMO

Accurate channel estimation is of utmost importance for massive MIMO systems to provide significant improvements in spectral and energy efficiency. In this work, we present a study on the distribution of a simple but yet effective and practical channel estimator for multi-cell massive MIMO systems suffering from pilot-contamination. The proposed channel estimator performs well under moderate to aggressive pilot contamination scenarios without previous knowledge of the inter-cell large-scale channel coefficients and noise power, asymptotically approximating the performance of the linear MMSE estimator as the number of antennas increases. We prove that the distribution of the proposed channel estimator can be accurately approximated by the circularly-symmetric complex normal distribution, when the number of antennas, M, deployed at the base station is greater than 10

Channel estimation for massive MIMO TDD systems assuming pilot contamination and frequency selective fading

Channel estimation is crucial for massive multiple-input multiple-output (MIMO) systems to scale up multi-user MIMO, providing significant improvement in spectral and energy efficiency. In this paper, we present a simple and practical channel estimator for multipath multi-cell massive MIMO time division duplex systems with pilot contamination, which poses significant challenges to channel estimation. The proposed estimator addresses performance under moderate to strong pilot contamination without previous knowledge of the inter-cell large-scale fading coefficients and noise power. Additionally, we derive and assess an approximate analytical mean square error (MSE) expression for the proposed channel estimator. We show through simulations that the proposed estimator performs asymptotically as well as the minimum MSE estimator with respect to the number of antennas and multipath coefficients

On the application of massive mimo systems to machine type communications

This paper evaluates the feasibility of applying massive multiple-input multiple-output (MIMO) to tackle the uplink mixed-service communication problem. Under the assumption of an available physical narrowband shared channel, devised to exclusively consume data traffic from machine type communications (MTC) devices, the capacity (i.e., number of connected devices) of MTC networks and, in turn, that of the whole system, can be increased by clustering such devices and letting each cluster share the same time-frequency physical resource blocks. Following this research line, we study the possibility of employing sub-optimal linear detectors to the problem and present a simple and practical channel estimator that works without the previous knowledge of the large-scale channel coefficients. Our simulation results suggest that the proposed channel estimator performs asymptotically, as well as the MMSE estimator, with respect to the number of antennas and the uplink transmission power. Furthermore, the results also indicate that, as the number of antennas is made progressively larger, the performance of the sub-optimal linear detection methods approaches the perfect interference-cancellation bound. The findings presented in this paper shed light on and motivate for new and exciting research lines toward a better understanding of the use of massive MIMO in MTC networks

Channel estimation for massive MIMO TDD systems assuming pilot contamination and flat fading

Channel estimation is crucial for massive massive multiple-input multiple-output (MIMO) systems to scale up multi-user (MU) MIMO, providing great improvement in spectral and energy efficiency. This paper presents a simple and practical channel estimator for multi-cell MU massive MIMO time division duplex (TDD) systems with pilot contamination in flat Rayleigh fading channels, i.e., the gains of the channels follow the Rayleigh distribution. We also assume uncorrelated antennas. The proposed estimator addresses performance under moderate to strong pilot contamination without previous knowledge of the cross-cell large-scale channel coefficients. This estimator performs asymptotically as well as the minimum mean square error (MMSE) estimator with respect to the number of antennas. An approximate analytical mean square error (MSE) expression is also derived for the proposed estimator

Visual-vestibular and postural analysis of motion sickness, panic, and acrophobia

Trigger motion sickness and can also have a role in some anxiety disorders. We explore a method to detect individual sensitivity to visual-vestibular unusual patterns, which can signal a vulnerability to develop motion sickness and possibly anxiety disorders such as a fear of heights and panic. 65 undergraduate students were recruited for the purposes of this study as voluntary participants (44 females); average age 21.65 years (SD=2.84) with normal or corrected to normal vision, without vestibular or postural deficiencies. Panic was assessed with the Albany Panic and Phobia Questionnaire, Motion Sickness with the Motion Sickness Susceptibility Questionnaire and Acrophobia was assessed by means of the Acrophobia Questionnaire. The Sharpened Romberg Test was used to test participant’s postural balance. The Rod and Frame Test (RFT) measures the participant’s ability to align a rod to the vertical within a titled frame providing a measure of error in the perception of verticality by degrees. This test was changed to measure the error offered when a participant’s head was tilted, and to trace the error caused by manipulating the vestibular system input. The main findings show only motion sickness to be correlated with significant errors while performing a visual-vestibular challenging situation, and fear of heights is the only anxiety disorder connected with postural stability, although all disorders (fear of heights, panic and motion sickness) are correlated between each other in the self- report questionnaires. All disorders are correlated to each other in the surveys, and might have some common visual-vestibular origin, in theory. The rod and frame test was exclusively correlated with motion sickness whereas the postural stability test only displayed sensibility to acrophobia. Panic disorder was correlated to neither the RFT nor the Romberg. Although this method was initially employed to increase sensibility in order to detect anxiety disorders, it ended up showing its value in the detection of motion sickness.National funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653). FCT/3599-PPCDT/121494/PTGrant IF/00217/ 2013info:eu-repo/semantics/publishedVersio

Työkaluna huonekuvaukset : Case: Ikaalisten Kylpylä

Opinnäytetyön tarkoituksena oli saada Ikaalisten Kylpylälle uudet, päivitetyt ja hyvin toimivat huonekuvaukset kaikista neljästä hotellista. Toimeksiantaja on Ikaalisten Kylpylä. Työn tutkimusongelmia olivat mitä kaikkea huonekuvauksista pitäisi löytyä, jotta ne palvelisivat mahdollisimman hyvin vastaanoton ja myyntipalvelun henkilökuntaa sekä erityisesti asiakkaita. Ongelmana oli myös mitä vanhoihin huonekuvauksiin tulisi lisätä ja miten parantaa niiden informatiivisuutta. Alkuperäiset huonekuvaukset ovat 1990-luvun alkupuolelta ja ne ovat paperilla kansioissa. Teoreettisena viitekehyksenä työssä on Komppulan & Boxbergin (2005)kerroksinen tuote eli hotellihuone kerroksisena tuotteena. Kerroksinen tuote muodostuu ydinpalvelusta sekä lisäarvoa tuottavista liitännäis- ja lisäpalveluista. Näitä ovat avustavat palvelut ja tukipalvelut. Aineistona olivat jo valmiina olevat huonekuvaukset ja omat päivitykseni niihin. Lomakehaastattelun vastauksia käytettiin myös aineistona tässä työssä. Tiedonkeruumenetelmä oli omien päivitettyjen tietojen koonti itse suunniteltuun huonekuvauslomakkeeseen, oma havainnointi sekä lomakehaastattelun tekeminen. Tutkimusmenetelmä oli kvalitatiivinen eli laadullinen. Empiirinen osa toteutettiin tekemällä kyselytutkimus Ikaalisten Kylpylän vastaanoton työntekijöille. Kymmenen seitsemästätoista vastaanotossa ja myyntipalvelussa työskentelevästä vastasi kyselyyn. Lomakehaastattelu oli puolistrukturoitu. Se sisälsi sekä avoimia kysymyksiä että monivalintakysymyksiä. Lomakehaastattelu oli muodoltaan informoitu kysely. Lomakkeet jaettiin vastaajille etukäteen ja heille kerrottiin mikä tutkimuksen tarkoitus on. Tutkimuksen tuloksena uudet päivitetyt huonekuvaukset tehtiin sähköiseen muotoon tietokoneille kaikkien helposti ulottuville. Huonekuvauksista tehtiin myös paperiset versiot. Tutkimus osoitti huonekuvaukset tarpeellisiksi ja hyödyllisiksi huoneiden lukumäärän ja erilaisuuden vuoksi. Johtopäätöksenä voidaan sanoa, että huonekuvaukset ovat hyödyllisiä ja ne tulivat tarpeeseen. Kehitysideoita tähän opinnäytetyöhön liittyen voisivat olla vielä tarkemmat huonekuvaukset.The purpose of this thesis was to update Ikaalinen Spa’s room descriptions. New and updated room descriptions were made of all Ikaalinen Spa’s four Hotels. The client of the study was Ikaalinen Spa. The aim of the study was to define the contents of room descriptions so that they, in the best possible way, serve both the personnel of the receptions and the sales as well as customers in particular. Additionally, the descriptions were to be improved and made more informative. Original room descriptions were made in early 1990’s and they are only in paper files. The theoretical framework was Komppula & Boxberg’s (2005) layered product. In this case it was a hotel room as a layered product. Layered product consists of nuclear service and additional and supplementary services which produce surplus value. These latter are supporting services and remedial services. The research material used in this thesis consists of the old room descriptions and gathered updates to them. The results from the interview study were also used as material in this thesis. New self-designed question forms were used in finding updated details. The material was also gathered through subjective observation and conducting the interview study by a questionnaire designed for that purpose. The research method was qualitative. The empirical part of the thesis was carried out by an interview study in the form of a questionnaire to Ikaalinen Spa’s employees who worked in the reception and sales service. Ten out of seventeen answered to the questionnaire. The interview form was semistructured with both open and closed questions. The interview study was by form an informed questioning. Questionnaires were delivered to respondents beforehand and the respondents were informed of the purpose of the study. As a result of this thesis new room descriptions were made into electronic form. They are now located on computers and in paper files in reception and sales service. The study showed that room descriptions are necessary and useful because of the number of rooms and differences between rooms. Development ideas in regard to this thesis could be more specific room descriptions

Extracorporeal photopheresis for the treatment of graft rejection in 33 adult kidney transplant recipients

Background - Extracorporeal photopheresis (ECP) has shown encouraging results in the prevention of allograft rejection in heart transplantation. However, the role of ECP in kidney transplant (KT) rejection needs to be determined. Methods - This multicentre retrospective study included 33 KT recipients who were treated with ECP for allograft rejection (23 acute antibody-mediated rejections (AMRs), 2 chronic AMRs and 8 acute cellular rejections (ACRs)). The ECP indications were KT rejection in patients who were resistant to standard therapies (n = 18) or in patients for whom standard therapies were contraindicated because of concomitant infections or cancers (n = 15). Results - At 12 months (M12) post-ECP, 11 patients (33%) had a stabilization of kidney function with a graft survival rate of 61%. The Banff AMR score (g + ptc + v) was a risk factor for graft loss at M12 (HR 1.44 [1.01-2.05], p < 0.05). The factorial mixed data analysis identified 2 clusters. Patients with a functional graft at M12 tended to have cellular and/or chronic rejections. Patients with graft loss at M12 tended to have acute rejections and/or AMR; higher serum creatinine levels; DSA levels and histologic scores of AMR; and a longer delay between the rejection and ECP start than those of patients with functional grafts. Conclusions - ECP may be helpful to control ACR or moderate AMR in KT recipients presenting concomitant opportunistic infections or malignancies when it is initiated early

High variability within Candida albicans transcription factor RLM1: Isolates from vulvovaginal infections show a clear bias toward high molecular weight alleles

Previous studies have correlated the severity of recurrent vulvovaginal Candida infections (VVC) and balanitis in patients from China with the presence of some dominant genotypes at the ORF RLM1. Here we tested VVC vs non-VVC isolates from Portugal, Brazil and Greece and, although the same genotypes were identified in VVC isolates, they were present in only five out of 150 strains. However, this analysis showed that VVC isolates presented a higher percentage of genotypes with similar high molecular weight alleles, in comparison with strains isolated from other biological source

Discovery of thiazolo [5,4-c] isoquinoline based compounds as acetylcholinesterase inhibitors through computational target prediction, molecular docking and bioassay

We thank Nathalie Reichmann and Leendert Hamoen (University of Amsterdam) for critical reading of the manuscript, Ana Velic (Proteome Center Tübingen) for help with proteome analysis and Mike VanNieuwenhze (Indiana University) for the generous gift of HADA. This study was funded by the European Research Council through grant ERC‐2017‐CoG‐771709 (to MGP), by national funds through FCT– Fundação para a Ciência e a Tecnologia, PTDC/BIA‐MIC/6982/2020 (to HV); PTDC/BIA‐PLA/3432/2012 (to SRF); FCT through MOSTMICRO‐ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020) and FCT fellowship SFRH/BD/147052/2019 (to BMS); by the Swiss National National Foundation through P300P3_155346 (to AJ); by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska‐Curie grant agreement No 839596 (to SS) and by the European Molecular Biology Organization through award ALTF 673‐2018 (to SS). Figure 6D and Appendix Fig S7 were created with Biorender.com .A computer-aided drug design (CADD) approach was developed for a focused chemical library comprising a series of sixteen thiazolo[5,4-c]isoquinoline derivatives. Little is known about this group of heteroaromatic compounds, both from the point of view of their synthesis and their biological properties. First, our CADD approach included target prediction by Mondrian conformal prediction with the ChEMBL database. The acetylcholinesterase (AChE) was identified as having a high probability of thiazolo[5,4-c]isoquinolines being active against it. Secondly, the molecular docking predictions revealed four promising thiazoloisoquinolines (2, 7, 13 and 14) according to their prominent ligand-protein energy scores and relevant binding affinities with the AChE pocket residues. The subsequent in vitro evaluation of promising hits and related ones revealed a set of novel AChE inhibitors. Therefore, the findings reported herein may provide a new strategy for discovering novel AChE inhibitors.publishersversionpublishe