1,721,178 research outputs found
DSP based CD and PMD Equalization Techniques in PDM-QPSK and PDM-16-QAM Receivers
No full textDigitale kohärente faseroptische Transmission mit Polarisationsmultiplex (polarization division multiplex, PDM) im Zusammenspiel mit Quadraturmodulation (quadrature amplitude modulation, QAM), QPSK (quadrature phase shift keying, Quadratur-Phasenmodulation) und 16-QAM steigert die spektrale Effektivität von optischen Netzwerken. In dieser Hinsicht gibt ein kohärenter Empfänger mit Polarisationsdiversität eine Darstellung des optischen Feldes in den elektrischen Bereich. Das vereinfacht effektiv die auf digitaler Signalverarbeitung (digital signal processing, DSP) basierende Kompensation von faseroptischen Beeinträchtigungen. Die Signalqualität ist bei Langstrecken und hoher Symbolrate beachtlich verschlechtert aufgrund von chromatischer Dispersion (chromatic dispersion, CD) und Polarisationsdispersion (polarization mode dispersion, PMD). Ein zweistufiger Ansatz zum Ausgleich ist erforderlich für eine effektive Kompensation dieser Störungen durch den Übertragungskanal im digitalen Bereich. In der ersten Stufe erfolgt die Kompensation der CD und deren Abschätzung für unkompensierte Kanäle mit viel CD. Dann, in der zweiten Stufe, wird mit einem Filter mit mehreren Ein- und Ausgängen (multiple-input multiple-output, MIMO) die PMD und die restliche CD kompensiert. Diese Dissertation zielt ab auf die umfangreiche Untersuchung, Entwicklung und Optimierung von DSP-basierten Techniken zur Kompensation von CD und PMD. Robuste DSP-Werkzeuge wurden vorgeschlagen, welche auf Simulationsegebnisse und Verhaltensanalysen bei 112 Gb/s PDM-QPSK und 224 Gb/s PDM-16-QAM basieren. In dieser Hinsicht trägt diese Dissertation die folgenden Arbeiten bei: Effiziente DSP-basierte CD-Entzerrung wurde untersucht und optimiert. DSP-basierte CD-Kompensationsverfahren wurden erweitert, um adaptiv zu sein gemäß den Anforderungen der modernen dynamischen ...Digital coherent fiberoptic transmission employing polarization-division multiplexing (PDM) along with the quadrature amplitude modulation (QAM) techniques, QPSK (quadrature phase shift keying) and 16-QAM, enhances spectral efficiency of optical networks. In this respect, polarization diversity coherent receiver gives a representation of the optical field in the electrical domain. This facilitates efficient digital signal processing (DSP) based compensation of fiberoptic transmission impairments. The signal quality is significantly impaired in long-haul transmission fiber links at a high symbol rate because of chromatic dispersion (CD) and polarization mode dispersion (PMD). A two-stage equalization approach is needed for efficient compensation of these channel impairments in the digital domain. In the first stage, CD compensation and estimation is required for uncompensated links with large amount of CD. Furthermore, as second stage, multiple-input multiple-output (MIMO) equalization is required for PMD and residual CD compensation. This Ph.D. work aims at extensive investigation, development and optimization of DSP based equalization techniques for the compensation of CD and PMD. Robust DSP tools have been proposed based on the simulation results and performance analysis of 112 Gb/s PDM-QPSK and 224 Gb/s PDM-16-QAM systems. In this perspective, this Ph.D. dissertation contributes the following work: Efficient DSP based CD equalization has been investigated and optimized. DSP based CD compensation methods have been extended to be adaptive as per the requirements of modern dynamic channel switching concept. Improved MIMO equalizers have been proposed and investigated for the compensation of PMD and residual CD.von M.Sc. Muhammad Fawad Panhwar; Erster Gutachter: Prof. Dr.-Ing. Reinhold Noé, Zweiter Gutachter: Prof. Dr. Peter SchreierTag der Verteidigung: 10.05.2016Universität Paderborn, Univ., Dissertation, 201
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
Health system capacity and readiness for delivery of integrated non-communicable disease services in primary health care: A qualitative analysis of the Ethiopian experience
Full text linkBackground
Non-communicable diseases (NCDs) now account for about 71% and 32% of all the deaths globally and in Ethiopia. Primary health care (PHC) is a vital instrument to address the ever-increasing burden of NCDs and is the best strategy for delivering integrated and equitable NCD care. We explored the capacity and readiness of Ethiopia’s PHC system to deliver integrated, people-centred NCD services.
Methods
A qualitative study was conducted in two regions and Federal Ministry of Health, Addis Ababa, Ethiopia. We carried out twenty-two key informant interviews with national and regional policymakers, officials from a partner organisation, woreda/district health office managers and coordinators, and PHC workers. Data were coded and thematically analysed using the World Health Organization (WHO) Operational Framework for PHC.
Results
Although the rising NCD burden is well recognised in Ethiopia, and the country has NCD-specific strategies and some interventions in place, we identified critical gaps in several levers of the WHO Operational Framework. Many compared the under-investment in NCDs contrasted with Ethiopia’s successful PHC models established for maternal and child health and communicable disease programs. Insufficient political commitment and leadership required to integrate NCD services at the PHC level and weaknesses in governance structures, inter-sectoral coordination, and funding for NCDs were identified as significant barriers to strengthening PHC capacity to address NCDs. Among the operational-focussed levers, fragmented information management systems and inadequate equipment and medicines were identified as critical bottlenecks. The PHC workforce was also considered insufficiently skilled and supported to provide NCD services in PHC facilities.
Conclusion
Strengthening NCD prevention and control through PHC in Ethiopia requires greater political commitment and investment at all health system levels. Prior success strategies with other PHC programs could be adapted and applied to NCD policies and practice, giving due consideration for the unique nature of the NCD program
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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