1,721,622 research outputs found
Heterogeneous integration in silicon photonics: opportunities and challenges: opinion
Full text linkAcknowledgments. The authors thank Tom Vanackere for assisting in drawing figures. The authors thank ePIXfab - the European silicon photonics alliance (https://epixfab.eu) for providing the data presented in this article
Implementierung von parallel-seriellen Filter-Strukturen auf Silizium micro-photonischer Plattform zur Kompensierung von Rest-Dispersion in optischen Kommunikationssystemen
No full textIn optischen Kommunikationssystemen besteht seit geraumer Zeit ein Interesse an der Definition optimaler Filterstrukturen. Eine rein-optische Implementierung solcher Filter eröffnet die Möglichkeit, Geschwindigkeitslimitierungen sowie den enormen Leistungsbedarf von elektronischen Filtern zu überwinden, insbesondere unabhängig von der Übertragungsrate. Integrierte optische Lösungen ermöglichen zusätzlich eine Integration in Empfängermodulen optischer Übertragungssysteme, wobei gerade eine Silizium-basierende Umsetzung den Vorteil der CMOS Kompatibilität gewährleistet, nicht zuletzt um eine Massentauglichkeit zu ermöglichen.
Die benötigten Module für solcher Filter sind Ringresonatoren, Bragg Gitter, Richtkoppler und Arrayed Waveguide Gratings (AWG). Für kohärent verbundene, Interferometer-basierte Filterstrukturen können diese Module in "voll-parallel" (AWG basierende) oder "voll-seriell" (Gitter-Filter) eingeteilt werden. Ein neuer Filteransatz wurde entworfen um die Vorteile des voll-parallelen mit dem voll-seriellen Filter zu verbinden, wobei der Name "parallel-serieller" Filter gewählt wurde. Diese Filterarchitektur hat das Potential, äußerst kompakte, hoch skalierbare Filter zu ermöglichen.
In dieser Arbeit wurde eine Mikro-Silizium-Photonische Implementierung eines solchen parallel-seriellen Filters zur Kompensierung von Restdispersion entworfen und hergestellt. Es wurde gezeigt, dass der parallel-serielle Filteransatz eine neue alternative ist, einige hundert ps/nm Restdispersion in hochbitratigen optischen Kommunikationssystemen zu kompensieren. Die Qualität des Filters ist über eine Emulation der gemessenen Filterkoeffizienten in einer kommerziellen Simulationsumgebung bestimmt worden. Ansätze zur weiteren Verbesserung des parallel-seriellen Filteransatzes wurden ferner aufgezeigt.In optical communication, there has been a continuous quest to determine an optimum filter architecture. Photonic implementation of a filter has the potential to overcome the electronic speed barrier and make the power consumption independent of the transmission rate. Integrated photonic implementation results in low power consumption and possible integration with the receiver module of a fiber optic transmission system. Furthermore, Silicon photonic implementation has the potential to bring CMOS compatibility, feasibility for mass-scale production and smaller footprint. Building blocks such as ring resonators, bragg gratings, directional couplers and Arrayed Waveguide Gratings (AWG) are employed to implement various filter schemes. For coherently connected interferometric schemes, the filter architectures can be categorized as fully-parallel (AWG based filters) or fully-serial (lattice filters). In an attempt to get the best out of both approaches, a new filter approach is conceived. Since this approach is based on the merger of fully-parallel and fully-serial approaches therefore it is termed as "Parallel-Serial". The proposed filter approach has potential to provide compact devices with possibility of easier scale-up. In this work, the micro-silicon photonic implementation of parallel-serial filter for tunable residual dispersion compensation is carried out. The results have shown that the parallel-serial filter approach provides a novel alternate to compensate few hundreds of ps/nm of residual dispersion for a high speed optical communication system. The effectiveness of the parallel-serial filter approach is determined by testing the performance of the fabricated devices in the emulation environment of a commercial software. Moreover, it has been shown that by modifying the design, the performance of the parallel-serial filter as a dispersion compensator can be improved further
Critical success factors of Malaysian Armed Forces digital library system / Abdul Rahim Abdul Rahman
Full text linkDigital Library System (DLS) refers to an online database that collects, creates, stores, distributes, and preserves digital objects, including text, images, video, and audio over a network. The present study aims to understand the critical success factors affecting user satisfaction and their continuous usage intention behaviour. This study employed updated DeLone and McLean IS Success Model (ISSM) and incorporated additional construct, namely perceived instrumental support to predict the critical success factors of Malaysian Armed Forces Digital Library System (MAFDLS). This study employed survey questionnaires to examine the research model and hypotheses developed. Five hundred twenty-four usable responses from military members who have accessed and used the digital library system were analysed using SPSS 25 and PLS 3.2.9. Within the context of military setting, it appears that perceived quality experience and perceived instrumental support as critical factors that triggered user satisfaction, net benefits and continuous usage intention behaviour. The findings specifically support that user satisfaction and net benefits play as sequential mediating roles between the perceived quality experience and continuous usage intention. In this study, perceived instrumental support affects user satisfaction and continuous usage and plays a moderating role between perceived quality experiences and user satisfaction. Hence, it is safe to say that users who are not satisfied with the system due to imperfect perceived quality experience factors would experience low difficulties. This study's perceived quality factors were MAF digital library environment, information relevance, system accessibility, navigation, and interface design. If they receive necessary instrumental supports from Malaysian Armed Forces Digital Library (MAFDL), this would increase users' perceptions of perceived instrumental support factors (such as education and training; technical support and communication support). While it is vital to satisfy the users' needs and satisfaction, Malaysian Armed Forces Digital Library (MAFDL) needs to bear in mind that not all group of users are the same. This study found that the different group specifics (such as geographical locations, level of experience and type of usage) have model effect differences as evidence to support that different group specifics have different perceptions of the overall digital library system evaluation criteria unique needs and opinions. The findings also uncover the potential challenges and issues faced by users when using the system. The results were synthesised, which would assist the management by re-strategizing the overall service delivery system by improving WebOPAC, KnowledgeBased Taxonomy, and MAF e-resource embedded in the system. The researcher produced strategic, tactical, and operational planning for future digital library system improvements based on full sampling or re-sampling group findings. Thus, the various planning of various levels of Malaysian Armed Forces (MAF) libraries was translated into a management action plan that acted as key performance indicators. This management action plan ensures that the military-users' needs are met to achieve a higher level of satisfaction on quality and instrumental support factors. It also meant getting higher organisational and individual impacts that benefit the users in having the system and having higher overall service delivery. In the end, it also meant to improve the continuous usage intention behaviour as the proxy to success behaviour of Malaysian Armed Forces Digital Library System (MAFDLS) future usage
12.5 Gbit/s discretely tunable InP-on-silicon filtered feedback laser with sub-nanosecond wavelength switching times
No full textIII-V-on-silicon filtered feedback discretely tunable laser with nanosecond switching times
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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
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