1,720,967 research outputs found
Signal processing algorithms for multiuser MIMO relay communication systems
Full text linkThe increasing demand for mobile applications such as streaming media, software updates, and location-based services involving group communications has prompted the need for wireless communication technologies that can support reliable high data rates. However, wireless channel is subject to signal fading that severely degrades the system spectral efficiency. By exploiting the spatial diversity, multiple-input multiple-output (MIMO) techniques can provide both theoretically attractive and technically practical solutions to combat channel fading. Moreover, in the case of long source-destination distance, single or multiple MIMO relay node(s) is necessary to combat the pathloss and/or shadowing effects of wireless channel and relay signals from the source to the destination.In this thesis, we focus on multiuser MIMO relay systems. We first present joint source, relay, and receiver optimization algorithms for the uplink system based on the minimum mean-squared error (MMSE) criterion subjecting to individual power constraints at the source and the relay nodes. The proposed algorithms outperform the existing techniques in terms of both MSE and bit-error-rate (BER). Next, in the downlink system, we consider multicasting multiple data streams among a group of users with the aid of a relay node, where all the nodes are equipped with multiple antennas. The downlink system performance is optimized subjecting to both power constraints at the source and the relay nodes and quality-of-service (QoS) constraints at the receivers.Then we present the duality between the uplink and the downlink of a multi-hop MIMO relay system. Based on this duality, we propose an optimal design of the source precoding matrix and relay amplifying matrices for multi-hop MIMO relay system with a nonlinear dirty paper coding (DPC)- based transmitter at the source node. The proposed nonlinear transmitter algorithm outperforms the existing decision feedback equalizer (DFE)-based receiver schemes.Multiuser MIMO relaying is then considered in an interference system where a group of transmitters communicate simultaneously with their desired destination nodes with the aid of multiple relay nodes, all equipped with multiple antennas. Transmit-relay-receive beamforming technique is exploited to minimize the total source and relay transmit power in conjunction with transmit power control such that a minimum QoS threshold is maintained at each receiver. The proposed scheme generalizes the existing single-hop MIMO interference systems and the single-antenna, dual-hop interference relay systems to the dual-hop interference MIMO relay systems with any number of source, relay, and destination nodes, all equipped with multiple antennas.The above algorithms are developed assuming that the instantaneous channel state information (CSI) knowledge of both the source-relay link and the relay-destination link is available at the scheduler. However, in practical relay communication systems, the instantaneous CSI is unknown, and therefore, has to be estimated. Hence, we finally propose a bandwidth efficient MIMO channel estimation algorithm that provides the destination node with full knowledge of all channel matrices involved in a dual-hop MIMO communication. The proposed approach attains smaller channel estimation error and is applicable for both one-way and two-way MIMO relay systems
Gerakan sosial muhammadiyah di era reformasi
No full textGerakan Aksi Bela Islam menunjukan kemampuan umat Islam dalam berdemokrasi di Indonesia sebagai negara demokrasi terbesar ketiga di dunia. Gerakan sosial dengan ciri solidaritas untuk suatu penentangan yang sama ditunjukan dengan cara mengagumkan lewat aksi Bela Islam. Namun banyaknya tudingan aksi ini bernuansa politis, membuat beberapa organisasi besar Islam menyatakan tidak melibatkan diri secara langsung dalam gerakan tersebut, salah satunya adalah Muhammadiyah. Muhammadiyah yang dikenal sebagai organisasi Islam yang berperan secara kultural lewat pendidikan, kesehatan dan pelayanan sosial, harus mengambil peran sebagai civil society di tengah kondisi umat Islam di Indonesia saat itu. Tulisan ini mengurai bagaimana organisasi besar Islam Muhammadiyah mengambil sikap dan cara berbeda dengan menyatakan diri tidak terlibat secara langsung secara keorganisasian. Menggunakan teori mobilisasi sumberdaya yang menjadi salah satu faktor dalam gerakan sosial, ditemukan bahwa sumber daya Muhammadiyah turut serta dalam gerakan sosial yang terwujud dalam Aksi Bela Islam. Para warga Muhammadiyah, fasilitas dan ketokohan dari para tokoh Muhammadiyah ikut menyukseskan gerakan Aksi Bela Islam. Muhammdiyah telah mengambil cara lain berperan sebagai civil society dengan ikut secara tidak langsung dalam gerakan sosial bersama organisasi-organisasi Islam lainnya. Penelitian ini menggunakan metode kualitatif
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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