1,720,990 research outputs found
Partial Spatial Coupling of LDPC Codes: Reducing the Gap to Capacity by Improving the Rate
No full textA different approach for constructing protograph-based spatially coupled low-density parity-check (SC-LDPC) codes is proposed. Instead of lifting multiple copies of an identical SC-LDPC protograph at the lifting stage of code construction, we divide the copies into fractions α ∈ [0,1] SC-LDPC protographs and β = 1-α uncoupled sequence of block LDPC protographs. The permutations in the edge bundles formed by two different protograph structures follow the multi-edge-type framework. The rate loss associated with SC-LDPC codes is reduced, and we obtain code ensembles with flexible rates, by varying β. We call these codes partial spatially coupled (PSC) LDPC codes, and through density evolution, we show that for data transmission over the binary erasure channel, the gap between channel capacity and thresholds of these codes is smaller as compared to SC-LDPC codes. The main bottleneck in the practical implementation of SC-LDPC codes is the rate loss. Conventionally, the rate loss can be reduced by taking large coupling length L , which however increases the decoding complexity. The proposed PSC-LDPC codes mitigate this tradeoff. Furthermore, these codes can also be decoded by the windowed decoder (WD), and through Monte Carlo simulations, we show that the WD performance of PSC-LDPC codes is better than that of SC-LDPC codes.
One-Step Ahead Decoding for Symmetric Block-Wise Concatenated BCH Codes
No full textSymmetric block-wise concatenated Bose-Chaudhuri-Hocquenghem (SBC-BCH) codes are known to provide strong error-correcting performance with an iterative hard-decision decoding (IHDD). This work shows that some properties of SBC-BCH codes allow one to readily increase the error-correcting capability of constituent BCH codes by one, i.e., from t to t+1 , which greatly improves the error-rate performance of SBC-BCH codes. To this end, we propose a new decoding algorithm that utilizes structural features of SBC-BCH codes in conjunction with an extension of the Berlekamp-Massey (BM) algorithm, namely the one-step-ahead (OSA) BM algorithm. This combination enables us to reduce the computational complexity and combat the inherent decoding ambiguity associated with the OSA-BM algorithm. Furthermore, we develop an analytical framework to evaluate the average number of candidate codewords returned by the OSA-BM algorithm and derive an upper bound on the probability of ambiguity. Then, we propose a decoding algorithm, called OSA-aided IHDD and conduct extensive performance evaluations and comparisons for error-correcting systems employing SBC-BCH codes with the proposed decoding algorithm. The performance evaluations show that the proposed OSA-aided IHDD considerably improves the error-rate performance in both the waterfall and error-floor regions.
A Novel Design Method of High Throughput Blockchain for 6G Networks: Performance Analysis and Optimization Model
No full textSharing is undoubtedly one of the most important features of 6G networks, and blockchain can provide an extended trust-as-a-service (TAAS) distributed sharing solution for 6G networks. However, as a special distributed technology system, blockchain naturally needs to face the "impossible triangle " problem: in the case of ensuring security and decentralization, scalability will inevitably become the Achilles heel of the blockchain system. This article will design a high-throughput blockchain system for 6G networks to achieve trusted sharing and efficient scheduling of network infrastructure, assist future networks in integrating an open Internet architecture, and realize the combination of openness and distributed control. We adopt a shard blockchain design and incorporate digital twins and federated learning; formulate an optimization model for maximizing the throughput of the blockchain network by getting the optimal number of shards, also analyzing other factors affecting the throughput such as service distribution; propose a security performance analysis model for the blockchain network to describe the measures taken against the Byzantine attacks on the network. Analysis and simulation results show that the transaction throughput of the proposed method can reach more than 30 times larger than that of a nonsharding scheme. They also show that when one-third of the nodes in the system are attacked, the consensus of the system is hardly affected; even if the number of nodes being attacked at the same time reaches half of the total number of nodes, the probability of the occurrence of failed shards is still less than 10<^>{-4} , and the system still has good survivability.
sj-pdf-1-mde-10.1177_23821205231170522 - Supplemental material for An Approach to Leadership Development and Patient Safety and Quality Improvement Education in the Context of Professional Identity Formation in Pre-Clinical Medical Students
No full textSupplemental material, sj-pdf-1-mde-10.1177_23821205231170522 for An Approach to Leadership Development and Patient Safety and Quality Improvement Education in the Context of Professional Identity Formation in
Pre-Clinical Medical Students by Hamza Inayat, Jacqueline Torti, Juliya Hemmett, Lorelei Lingard, Brandon Chau, Ali Inayat, Jason L. Elzinga and Nabil Sultan in Journal of Medical Education and Curricular Development</p
sj-pdf-3-mde-10.1177_23821205231170522 - Supplemental material for An Approach to Leadership Development and Patient Safety and Quality Improvement Education in the Context of Professional Identity Formation in Pre-Clinical Medical Students
No full textSupplemental material, sj-pdf-3-mde-10.1177_23821205231170522 for An Approach to Leadership Development and Patient Safety and Quality Improvement Education in the Context of Professional Identity Formation in
Pre-Clinical Medical Students by Hamza Inayat, Jacqueline Torti, Juliya Hemmett, Lorelei Lingard, Brandon Chau, Ali Inayat, Jason L. Elzinga and Nabil Sultan in Journal of Medical Education and Curricular Development</p
sj-pdf-2-mde-10.1177_23821205231170522 - Supplemental material for An Approach to Leadership Development and Patient Safety and Quality Improvement Education in the Context of Professional Identity Formation in Pre-Clinical Medical Students
No full textSupplemental material, sj-pdf-2-mde-10.1177_23821205231170522 for An Approach to Leadership Development and Patient Safety and Quality Improvement Education in the Context of Professional Identity Formation in
Pre-Clinical Medical Students by Hamza Inayat, Jacqueline Torti, Juliya Hemmett, Lorelei Lingard, Brandon Chau, Ali Inayat, Jason L. Elzinga and Nabil Sultan in Journal of Medical Education and Curricular Development</p
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
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