3,598 research outputs found
Adaptive MBER space-time DFE assisted multiuser detection for SDMA systems
In this contribution we propose a space-time decision feedback equalization (ST-DFE) assisted multiuser detection (MUD) scheme for multiple antenna aided space division multiple access systems. A minimum bit error rate (MBER) design is invoked for the MUD, which is shown to be capable of improving the achievable bit error rate performance over that of the minimum mean square error (MMSE) design. An adaptive MBER ST-DFE-MUD is proposed using the least bit error rate algorithm, which is demonstrated to consistently outperform the least mean square (LMS) algorithm, while achieving a lower computational complexity than the LMS algorithm for the binary signalling scheme. Simulation results demonstrate that theMBER ST-DFE-MUD is more robust to channel estimation errors as well as to error propagation imposed by decision feedback errors, compared to the MMSE ST-DFE-MUD
Minimum Bit-Error Rate Design for Space-Time Equalisation-Based Multiuser Detection
A novel minimum bit-error rate (MBER) spaceâtime equalization (STE)-based multiuser detector (MUD) is proposed for multiple-receive-antenna-assisted space-division multiple-access systems. It is shown that the MBER-STE-aided MUD significantly outperforms the standard minimum mean-square error design in terms of the achievable bit-error rate (BER). Adaptive implementations of the MBER STE are considered, and both the block-data-based and sample-by-sample adaptive MBER algorithms are proposed. The latter, referred to as the least BER (LBER) algorithm, is compared with the most popular adaptive algorithm, known as the least mean square (LMS) algorithm. It is shown that in case of binary phase-shift keying, the computational complexity of the LBER-STE is about half of that required by the classic LMS-STE. Simulation results demonstrate that the LBER algorithm performs consistently better than the classic LMS algorithm, both in terms of its convergence speed and steady-state BER performance. Index TermsâAdaptive algorithm, minimum bit-error rate (MBER), multiuser detection (MUD), spaceâtime processing
Fading Performance Evaluation of Adaptive MSER Beamforming Receiver for QAM Systems
The ever-increasing demand for mobile communication capacity has motivated the development of adaptive antenna array assisted spatial processing techniques for bandwidth efficiency, high-throughput quadrature amplitude modulation (QAM) systems. We evaluate performance of adaptive beamforming assisted detection for QAM systems in Rayleigh fading environments. An adaptive minimum symbol error rate design, referred to as the least symbol error rate, is shown to be capable of successfully operating in fast fading conditions and to consistently outperform the conventional adaptive beamforming benchmarker based on the least mean square algorithm
âThey just don't understand usâ: The role of felt understanding in intergroup relations
This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this recordWe report 5 studies examining the unique role of felt understanding in intergroup relations. In intergroup terms, felt understanding is the belief that members of an outgroup understand and accept the perspectives of ingroup members, including ingroup membersâ beliefs, values, experiences, and self-definition/identity. In Studies 1 (ScotlandâU.K. relations; N = 5,033) and 2 (U.K.âEU relations; N = 861) felt understanding consistently and strongly predicted outcomes such as trust, action intentions, and political separatism, including participantsâ actual âBrexitâ referendum vote in Study 2. These effects were apparent even when controlling for outgroup stereotypes and metastereotypes. Felt understanding was a unique predictor of outgroup trust and forgiveness in Study 3 (CatholicâProtestant relations in Northern Ireland; N = 1,162), and was a powerful predictor of political separatism even when controlling for specific, relational appraisals including negative interdependence and identity threat in Study 4 (BasqueâSpanish relations; N = 205). Study 5 (N = 190) included a direct manipulation of felt understanding, which had predicted effects on evaluation of the outgroup and of ingroup-outgroup relations. Overall, the findings provide converging evidence for the critical role of felt understanding in intergroup relations. We discuss future research possibilities, including the emotional correlates of felt understanding, and its role in intergroup interactions
Stimulating the innovation potential of 'routine' workers through workplace learning
Governments worldwide seek to upgrade the âbasic skills' of employees deemed to have low literacy and numeracy, in order to enable their greater productivity and participation in workplace practices. A longitudinal investigation of such interventions in the United Kingdom has examined the effects on employees and on organizations of engaging in basic skills programmes offered in and through the workplace. âTrackingâ of employees in selected organizational contexts has highlighted ways in which interplay between formal and informal workplace learning can help to create the environments for employees in lower grade jobs to use and expand their skills. This workplace learning is a precondition, a stimulus and an essential ingredient for participation in employee-driven innovation, as workers engage with others to vary, and eventually to change, work practices. © 2010, SAGE Publications. All rights reserved
Antonio Gramsciâs impact on critical pedagogy
This paper provides an account of Antonio Gramsciâs impact on the area of critical pedagogy. It indicates the Gramscian influence on the thinking of major exponents of the field. It foregrounds Gramsci's ideas and then indicates how they have been taken up by a selection of critical pedagogy exponents who were chosen on the strength of their identification and engagement with Gramsci's ideas, some of them even having written entire essays on Gramsci. The essay concludes with a discussion concerning an aspect of Gramsci's concerns, the question of powerful knowledge, which, in the present author's view, provides a formidable challenge to critical pedagogues.peer-reviewe
The participation paradigm in audience research
As today's media simultaneously converge and diverge, fusing and hybridizing across digital services and platforms, some researchers argue that audiences are dead-long live the user! But for others, it is the complex interweaving of continuities and changes that demands attention, especially now that audiencing has become a vital mode of engaging with all dimensions of daily life. This article asks how we should research audiences in a digital networked age. I argue that, while many avenues are being actively pursued, many researchers are concentrating on the notion of participation, asking, on the one hand, what modes of participation are afforded to people by the particular media and communication infrastructures which mediate social, cultural or political spheres of life? And, on the other hand, how do people engage with, accede to, negotiate or contest this as they explore and invent new ways of connecting with each other through and around media? The features of this emerging participation paradigm of audience research are examined in this article
Towards Emotion Recognition: A Persistent Entropy Application
Emotion recognition and classification is a very active area of research. In
this paper, we present a first approach to emotion classification using
persistent entropy and support vector machines. A topology-based model is
applied to obtain a single real number from each raw signal. These data are
used as input of a support vector machine to classify signals into 8 different
emotions (calm, happy, sad, angry, fearful, disgust and surprised)
Supraglacial rivers on the northwest Greenland Ice Sheet, Devon Ice Cap, and Barnes Ice Cap mapped using Sentinel-2 imagery
Supraglacial rivers set efficacy and time lags by which surface meltwater is routed to the englacial, subglacial, and proglacial portions of ice masses. However, these hydrologic features remain poorly studied mainly because they are too narrow (typically <30âm) to be reliably delineated in conventional moderate-resolution satellite images (e.g., 30âm Landsat-8 imagery). This study demonstrates the utility of 10âm Sentinel-2 Multi-Spectral Instrument images to map supraglacial rivers on the northwest Greenland Ice Sheet, Devon Ice Cap, and Barnes Ice Cap, covering a total area of âŒ10,000 km2. Sentinel-2 and Landsat-8 both capture overall supraglacial drainage patterns, but Sentinel-2 images are superior to Landsat-8 images for delineating narrow and continuous supraglacial rivers. Sentinel-2 mapping across the three study areas reveals a variety of supraglacial drainage patterns. In northwest Greenland near Inglefield Land, subparallel supraglacial rivers up to 55âkm long drain meltwater directly off the ice sheet onto the proglacial zone. On the Devon and the Barnes ice caps, shorter supraglacial rivers (up to 15â30âkm long) are commonly interrupted by moulins, which drain internally drained catchments on the ice surface to subglacial systems. We conclude that Sentinel-2 offers strong potential for investigating supraglacial meltwater drainage patterns and improving our understanding of the hydrological conditions of ice masses globally
Polyphase midâlatitude glaciation on Mars:Chronology of the formation of superposed glacierâlike forms from craterâcount dating
Reconstructing Mars's glacial history informs understanding of its physical environment and past climate. The known distribution of viscous flow features (VFFs) containing water ice suggests that its midâlatitudes were glaciated during the Late Amazonian period (the last several hundred million years). The identification of a subgroup of VFFsâcalled superposed glacier like forms (SGLFs)âflowing onto other VFFs, indicates multiple glacial phases may have occurred during this time. To explore the history and spatial extent of these glaciations, we record the distribution of SGLFs globally and use impactâcrater counting to date the SGLFs and the VFFs onto which they flow. Our inventory expands the handful of SGLFs reported in earlier literature to include 320 located throughout the midâlatitudes. Our dating reveals these SGLFs to be much younger than their underlying VFFs, which implies a spatiallyâasynchronous glaciation. SGLFs have been forming since âŒ65 Ma, and their ages are clustered in two distinct groups around 2â20 and 45â65 Ma, whereas the ages of their underlying VFFs span the last âŒ300 Ma diffusely. We discuss these results in the light of wellâknown uncertainties with the craterâdating method and infer that while ice sheets decayed over the Late Amazonian period, alpine glaciers waxed and waned in at least two major cycles before their final demise approximately two million years ago
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