Priority Queue VLSI Architecture for Sequential Decoder of Polar Codes

<div>The VLSI architectures for stack or priority queue (PQ) are required in the implementation of stack or sequential decoders of polar codes. Such type of decoders provide good BER performance keeping complexity low. Extracting the best and the worst paths from PQ is the most complex operation in terms of both latency and complexity, because this operation requires full search along priority queue. In this work we propose a low latency and low complexity parallel hardware architecture for PQ, which is based on the systolic sorter and simplified sorting primitives. The simulation results show that just small BER degradation is introduced compared to ideal full sorting networks. Proposed PQ architecture is implemented in FPGA, the synthesis results are presented for all components of PQ.</div>

Priority Queue VLSI Architecture for Sequential Decoder of Polar Codes

<div>The VLSI architectures for stack or priority queue (PQ) are required in the implementation of stack or sequential decoders of polar codes. Such type of decoders provide good BER performance keeping complexity low. Extracting the best and the worst paths from PQ is the most complex operation in terms of both latency and complexity, because this operation requires full search along priority queue. In this work we propose a low latency and low complexity parallel hardware architecture for PQ, which is based on the systolic sorter and simplified sorting primitives. The simulation results show that just small BER degradation is introduced compared to ideal full sorting networks. Proposed PQ architecture is implemented in FPGA, the synthesis results are presented for all components of PQ.</div>

Timeliness of routine childhood vaccination in low- and middle-income countries, 1978–2021: Protocol for a scoping review to map methodologic gaps and determinants

The literature on the timeliness of childhood vaccination (i.e. vaccination at the earliest appropriate age) in low-and middle-income countries has important measurement and methodological issues that may limit their usefulness and cross comparison. We aim to conduct a comprehensive scoping review to map the existing literature with a key focus on how the literature on vaccination timeliness has evolved, how it has been defined or measured, and what determinants have been explored in the period spanning the last four decades. This scoping review protocol was developed based on the guidance for scoping reviews from the Joanna Briggs Institute. We will include English and French language peer-reviewed publications and grey literature on the timeliness of routine childhood vaccination in low-and middle-income countries published between January 1978 through to 2021. A three-step search strategy that involves an initial search of two databases to refine the keywords, a full search of all included electronic databases, and screening of references of previous studies for relevant articles missing from our full search will be employed. The search will be conducted in five electronic databases: MEDLINE, EMBASE, Global Health, CINAHL and Web of Science. Google search will also be conducted to identify relevant grey literature on vaccination timeliness. All retrieved titles from the search will be imported into Endnote X9.3.3 (Clarivate Analytics) and deduplicated. Two reviewers will screen the titles, abstracts and full texts of publications for eligibility using Rayyan–the web based application for screening articles for systematic reviews. Using a tailored data extraction template, we will extract relevant information from eligible studies. The study team will analyse the extracted data using descriptive statistical methods and thematic analysis. The results will be presented using tables, while charts and maps will be used to aid the visualisation of the key findings and themes. The proposed review will generate evidence on key methodological gaps in the literature on timeliness of childhood vaccination. Such evidence would shape the direction of future research, and assist immunisation programme managers and country-level stakeholders to address the needs of their national immunisation system.

LOCATE: a prospective evaluation of the value of Leveraging Ongoing Citation Acquisition Techniques for living Evidence syntheses

Background Living systematic reviews (LSRs) can expedite evidence synthesis by incorporating new evidence in real time. However, the methods needed to identify new studies in a timely manner are not well established. Objectives To explore the value of complementary search approaches in terms of search performance, impact on results and conclusions, screening workload, and feasibility compared to the reference standard. Methods We developed three complementary search approaches for a systematic review on treatments for bronchiolitis: Automated Full Search, PubMed Similar Articles, and Scopus Citing References. These were automated to retrieve results monthly; pairs of reviewers screened the records and commented on feasibility. After 1 year, we conducted a full update search (reference standard). For each complementary approach, we compared search performance (proportion missed, number needed to read [NNR]) and reviewer workload (number of records screened, time required) to the reference standard. We investigated the impact of the new trials on the effect estimate and certainty of evidence for the primary outcomes. We summarized comments about feasibility. Results Via the reference standard, reviewers screened 505 titles/abstracts, 24 full texts, and identified four new trials (NNR 127; 12.4 h). Of the complementary approaches, only the Automated Full Search located all four trials; these were located 6 to 12 months sooner than via the reference standard but did not alter the results nor certainty in the evidence. The Automated Full Search was the most resource-intensive approach (816 records screened; NNR 204; 17.1 h). The PubMed Similar Articles and Scopus Citing References approaches located far fewer records (452 and 244, respectively), thereby requiring less screening time (9.4 and 5.2 h); however, each approach located only one of the four new trials. Reviewers found it feasible and convenient to conduct monthly screening for searches of this yield (median 15–65 records/month). Conclusions The Automated Full Search was the most resource-intensive approach, but also the only to locate all of the newly published trials. Although the monthly screening time for the PubMed Similar Articles and Scopus Citing Articles was far less, most relevant records were missed. These approaches were feasible to integrate into reviewer work processes. Systematic review registration Open Science Framework. 10.17605/OSF.IO/6M28H.

Motion Estimation for Gray Level Videos Using Different Block Matching Algorithms

Motion Estimation (ME) is a very important operation in video coding. In order to reduce complexity of computations involved in ME and to increase quality of this process, many Block Matching Motion Estimation (BMME) Algorithms are proposed. The aim of this paper is to compare between these algorithms and find the best one. Seven BMME algorithms are used in this paper. The performance of each algorithm is evaluated for different types of motion to determine the best one of these algorithms. The evaluation is based on search points, and Peak Signal to Noise Ratio (PSNR). The simulation shows that Hexagonal Search is faster than all other Block Matching (BM) algorithms used in this paper regardless the type of video because it requires less number of search points to evaluate motion vectors for the video sequence. It requires 11.2424 average search point (SP) for small motions and 13.9708 for fast motions. It also gives a good quality that is close enough to the quality given by Full Search

EVOLUTIONARY METHODS AND GENETIC ALGORITHMS FOR NUMERICAL CALCULATION OF THE OPTIMAL DESIGN OF NON-RIGID ROAD SURFACES

В статье представлена оптимизационная модель для расчета конструкций нежестких дорожных одежд, обосновано применение эволюционных алгоритмов в сочетании с полным перебором и параллельными вычислениями и описан разработанный гибридный генетический алгоритм The article presents an optimization model for calculating structures of non-rigid road surfaces, justifies the use of evolutionary algorithms in combination with full search and parallel calculations, and describes the developed hybrid genetic algorithm for optimizing the design of non-rigid road surfaces at the cost of materials of structural layers.

Fast Search Method Based on Vector Quantization for Raman Spectroscopy Identification

In spectroscopy, matching a measured spectrum to a reference spectrum in a large database is often computationally intensive. To solve this problem, we propose a novel fast search algorithm that finds the most similar spectrum in the database. The proposed method is based on principal component transformation and provides results equivalent to the traditional full search method. To reduce the search range, hierarchical clustering is employed, which divides the spectral data into multiple clusters according to the similarity of the spectrum, allowing the search to start at the cluster closest to the input spectrum. Furthermore, a pilot search was applied in advance to further accelerate the search. Experimental results show that the proposed method requires only a small fraction of the computational complexity required by the full search, and it outperforms the previous methods.

Reward Does Not Modulate the Preview Benefit in Visual Search

Preview benefit refers to faster search for a target when a subset of distractors is seen prior to the search display. We investigated whether reward modulates this effect. Participants identified a target among non-targets on each trial. On “preview” trials, placeholders occupied half the search array positions prior to the onset of the full array. On “non-preview” trials, no placeholders preceded the full search array. On preview trials, the target could appear at either a placeholder position (old-target-location condition) or a position where no placeholder had been (new-target-location condition). Critically, the color of the stimulus array indicated whether participants would earn reward for a correct response. We found a typical preview benefit, but no evidence that reward modulated this effect, despite a manipulation check showing that stimuli in the reward-signaling color tended to capture attention on catch trials. The results suggest that reward learning does not modulate the preview benefit.

LOCATE: A Prospective Evaluation of the Value of Leveraging Ongoing Citation Acquisition Techniques for Living Evidence Syntheses

Background. Living systematic reviews (LSRs) can expedite evidence synthesis by incorporating new evidence in real time. However, the methods needed to identify new studies in a timely manner are not well established. Objectives. To explore the value of complementary search approaches in terms of search performance, impact on results and conclusions, screening workload and feasibility compared to the reference standard.Methods. We developed three complementary search approaches for a systematic review on treatments for bronchiolitis: Automated Full Search, Pubmed Similar Articles, and Scopus Citing References. These were automated to retrieve results monthly; pairs of reviewers screened the records and commented on feasibility. After one year, we conducted a full update search (reference standard). For each complementary approach, we compared search performance (proportion missed, number needed to read [NNR]) and reviewer workload (number of records screened, time required) to the reference standard. We investigated the impact of the new trials on the effect estimate and certainty of evidence for the primary outcomes. We summarized comments about feasibility. Results. Via the reference standard, reviewers screened 505 titles/abstracts, 24 full texts, and identified four new trials (NNR 126.6; 12.4 hours). Of the complementary approaches, only the Automated Full Search located all four trials; these were located six to 12 months sooner than via the reference standard but did not alter the results nor certainty in the evidence. The Automated Full Search was the most resource-intensive approach (816 records screened; NNR 204.1; 17.1 hours). The Pubmed Similar Articles and Scopus Citing References approaches located far fewer records (452 and 244, respectively), thereby requiring less screening time (9.4 and 5.2 hours); however, each approach located only one of the four new trials. Reviewers found it feasible and convenient to conduct monthly screening for searches of this yield (median 15-65 records/month). Conclusions. The Automated Full Search was the most resource-intensive approach, but also the only to locate all of the newly published trials. Although the monthly screening time for the Pubmed Similar Articles and Scopus Citing Articles was far less, most relevant records were missed. These approaches were feasible to integrate into reviewer work processes.Study Protocol. Posted 25 October 2018 on the Open Science Framework, https://osf.io/wxebg/ doi: 10.17605/OSF.IO/6M28H.