502 research outputs found
Channel code division multiple access and its multilevel structured LDPC based instantiation
No full textIn this paper, we introduce and outline the concept of Channel Code Division Multiple Access (CCDMA) using a design example based on the recently proposed Multilevel Structured (MLS) LDPC codes. We succeeded in making the memory requirements of the multi-user transceiver to become practically independent of the total number of users supported by the system as well as ascertain that each user benefits from the same Quality of Service (QoS). Finally, we will demonstrate that despite their beneficial compact structure, the proposed MLS LDPC codes do not suffer from any Bit Error Ratio (BER) or Block Error Ratio (BLER) performance degradation, when compared to an otherwise identical benchmarker scheme using significantly more complex LDPC codes having pseudo-random parity-check matrices
Generalized MIMO transmit preprocessing using pilot symbol assisted rateless codes
No full textIn this paper, we propose a generalized multiple-input multiple-output (MIMO) transmit preprocessing system, where both the channel coding and the linear MIMO transmit precoding components exploit the knowledge of the channel. Moreover, we also propose a novel technique, hereby referred to as pilot symbol assisted rateless (PSAR) coding, where a predetermined fraction of binary pilot symbols is interspersed with the channel-coded bits at the channel coding stage, instead of multiplexing the pilots with the data symbols at the modulation stage, as in classic pilot symbol assisted modulation (PSAM). We will subsequently demonstrate that the PSAR code-aided transmit preprocessing scheme succeeds in gleaning more beneficial knowledge from the inserted pilots, because the pilot bits are not only useful for estimating the channel at the receiver, but they are also beneficial in terms of significantly reducing the computational complexity of the rateless channel decoder
Multilevel structured low-density parity-check codes for AWGN and Rayleigh channels
No full textWe propose a novel class of protograph low-density parity-check (LDPC) codes having a combinatorial rather than a random structure, which are termed multilevel-structured (MLS) LDPC codes. It is demonstrated that they posses a strikingly simple structure and, thus, benefit from reduced storage requirements, hardware-friendly implementations, and low-complexity encoding. Our simulation results provided for both additive white Gaussian noise (AWGN) and uncorrelated Rayleigh (UR) channels demonstrate that these advantages accrue without compromising the attainable bit error ratio (BER) and block error ratio (BLER) performance, when compared with their previously proposed more complex random-construction-based counterparts, as well as with other structured codes of the same length
Saving a Tree Genus: Researchers Are Working Toward an Ash Hybrid Resistant to Emerald Ash Borer
No full textAuthor Institution (Herms): Department of Entomology, The Ohio State University; Author Institution (Bonello): Department of Plant Pathology, The Ohio State Universit
Design of low-density parity-check codes: An overview
No full textThis article provides an overview of the conflicting design tradeoffs of low-density parity-check (LDPC) codes and thus advocates a more holistic approach to their design for wireless channels. We reveal some of the intricate interdependencies of the LDPC code parameters and hence recommend designing codes that strike an attractive tradeoff concerning a number of desirable attributes, rather than simply designing codes that closely approach capacity but possess less-attractive hardware implementations
The role of Crassostrea gigas (Thunberg, 1793) in the vertical microplastic transfer: A plankton-benthos linkage laboratory protocol
No full textMicroplastics are nowadays recognized as one of the most important pollution sources in the aquatic environment. Their presence has been investigated and certified in various parts of the globe and, most importantly, in a wide variety of species belonging to different trophic levels. However, the process of microplastics vertical distribution among the trophic chains is yet to be disclosed, especially when approaching the plankton-benthos linkage and its consequences in terms of plastic particles transfer from the water column to the benthic biota and environment. We propose a laboratory protocol that simulates microplastics inclusion in organic matter and their subsequent ingestion by the Pacific Oyster Crassostrea gigas (Thunberg, 1793) by the mean of Na-alginate microspheres containing synthetic microplastics. The bivalve sorting mechanisms were also tested by providing phytoplanktonic microalgae and evaluating their proficiency in feeding selectivity. Overall, the Pacific oyster specimens exposed to organic coated microplastics ingested a third (0.1 MP/h vs. 0.3 MP/h) of plastic particles whenever microalgae were available in solution under the same conditions
Older men learning through religious and political affiliations : case studies from Malta
No full textThis article examines two case studies from Malta that focus on older men learning through informal channels. The first case study investigated the role of a community-based organisation – namely, a religious confraternity dedicated to ‘Our Lady of Immaculate Conception’ of the village of Mqabba – as an avenue for informal learning activities for older men. The second case study investigated the connection between affiliation in the Labour Party Veterans’ branch of the Labour Party (Malta) and informal learning. The case studies were carried out by employing a qualitative-methodological framework whereby data was collected through semi-structured interviews. The intent was to reveal the perceived interests and expectations regarding what would be considered a satisfying lifestyle in the context of membership of older men in both organisations. Findings reveal the benefits that older men enjoy through participation in such organisations, including increased levels of independence, improved social participation, and positive effects on participants’ self-esteem and personal confidence. Informants report that membership also contributed to their mental and physical health and to increased activity. Many underlined how participation aided them in escaping boredom and keeping in touch with the outside world. Findings also reveal that only a few informants were simultaneously involved in organisations and activities not related to their religious and political affiliations, which highlights the importance of both informal learning channels in helping older men lead successful and active livespeer-reviewe
Rip currents investigation on a Ligurian pocket beach, NW Mediterranean
No full textWave-induced currents play a key role in coastal sedimentary and hydrodynamics processes, and in particular, rip currents are probably the most widely studied aspect. Rip currents are characterized by a strong seaward-directed flow, which can transport sediments, planktonic organisms, nutrients, pollutants, and suspended material. However, rip currents are also a hazard for beachgoers and constitute a well known risk to bathers. Several studies have been conducted to describe rip current dynamics and their implications along oceanic beaches, although only a few studies have considered rip dynamics along Mediterranean coasts. This study is an accurate investigation of rip current development in the Levanto pocket beach (Ligurian sea, NW Italy). Coastal video-monitoring, coastal modelling, field surveys, and laboratory analysis are well known methodologies used to study the behaviour of rip currents, but each has its limitations. To overcome this problem, we propose an integrated approach where different tools are integrated among these to obtain mutual validation among several different approaches. The results show how the rip currents investigated in this study can reach and exceed velocities of 1 ms−1, comparable with those of oceanic rip currents, and how these are a key component in the coastal processes that occur along a Mediterranean pocket beach
Charmaine Bonello, Boys, early literacy and children’s rights in a postcolonial context [book review]
No full textIt is high time that we beat the boredom and unease some
boys equate with reading and writing. The author,
Charmaine Bonello, is a mother of two boys, an educator
with many years of experience with boys in the early years,
an advocate of children’s rights, a researcher and lecturer
within the Faculty of Education of the University of Malta.
Through this publication, she invites readers to listen to
the unheard voices of the boys in her study. She firmly
believes that all children deserve, and have a right, to an
excellent and meaningful reading experience so they may
become passionate about reading and writing. To capture
these voices Bonello held focus group interviews with 14
boys, aged 5 to 6 years (Year 1 in Primary School) old
within three State Schools in Malta.
In Chapter 1, Bonello presents the historical,
cultural, social and economic context for the study. The
researcher’s values, beliefs, attitudes and work experience
guided her to conduct a mixed method case study which
explores boys’ underachievement in literacy in early years
education in Malta. Although the participants were young
boys, elements of the context in which they live can be
traced much further back in time. [excerpt]peer-reviewe
Le rôle de l’Intelligence Artificielle dans l’exploration des limites de l’humain : La Bête (2023) de Bertrand Bonello
No full textThis study analyzes the image of Artificial Intelligence (AI) in Bertrand Bonello\u27s film La Bête (2023), using an approach that combines cinematographic analysis and genetic criticism. It focuses on the genesis and exogenesis of the film, based on the pre-production document “Découpage LA BÊTE,” which was kindly shared by the director. A loose adaptation of Henry James\u27 short novel The Beast in the Jungle (1903), La Bête explores one of its major themes: the emotional dimension that distinguishes humans from machines. Invisible yet omnipresent, AI questions the relationship between the creator and his work, as well as the role of “artificial persons” in contemporary society. Through complex, non-linear narration, unsettling visual effects, and a mix of cinematic genres, Bonello presents a science fiction work that depicts a near future where AI dominates the world. The figure of AI, which elicits both fascination and repulsion, raises questions about the impact of new technologies on everyday life and challenges the boundaries of human identity.Cette étude analyse l’image de l’Intelligence Artificielle (IA) dans le film La Bête (2023) de Bertrand Bonello, en utilisant une approche combinant analyse cinématographique et critique génétique. L’étude s’intéresse à la genèse et à l’exogenèse du film, en se basant sur le document de préproduction « Découpage LA BÊTE », aimablement partagé par le réalisateur. Adaptation libre du court roman La Bête dans la jungle (1903) d\u27Henry James, La Bête reprend l’un de ses thèmes majeurs : la dimension affective qui distingue l’humain des machines. Invisible mais omniprésente, l\u27IA interroge la relation entre le créateur et son œuvre, et le rôle des « personnes artificielles » dans la société contemporaine. À travers une narration complexe et non-linéaire, des effets visuels déstabilisants et un mélange des genres cinématographiques, Bonello propose une œuvre de science-fiction qui représente un futur proche où l\u27IA gouverne le monde. La figure de l\u27IA, qui suscite à la fois fascination et répulsion, soulève des questionnements sur l\u27impact des nouvelles technologies dans la vie quotidienne, et interroge les frontières de l’identité humaine
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