| 71. |
- Adelani, David Ifeoluwa, et al.
(författare)
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MasakhaNER: Named Entity Recognition for African Languages
- 2021
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Ingår i: Transactions of the Association for Computational Linguistics. - : MIT Press. - 2307-387X. ; 9, s. 1116-1131
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Tidskriftsartikel (refereegranskat)abstract
- We take a step towards addressing the under-representation of the African continent in NLP research by bringing together different stakeholders to create the first large, publicly available, high-quality dataset for named entity recognition (NER) in ten African languages. We detail the characteristics of these languages to help researchers and practitioners better understand the challenges they pose for NER tasks. We analyze our datasets and conduct an extensive empirical evaluation of state-of-the-art methods across both supervised and transfer learning settings. Finally, we release the data, code, and models to inspire future research on African NLP.
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| 72. |
- Adermark, Louise, 1974, et al.
(författare)
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Prospective association between use of electronic cigarettes and use of conventional cigarettes: a systematic review and meta-analysis
- 2021
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Ingår i: Erj Open Research. - Sheffield : European Respiratory Society (ERS). - 2312-0541. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of this systematic review and meta-analysis was to assess the association between e-cigarette use and subsequent initiation or recurrence of cigarette smoking. Data sources A systematic literature search was finalised on 11 November 2019 using PubMed (including MEDLINE), EMBASE, Cochrane Library, Scopus, PubMed Health, NICE Evidence Search, PROSPERO, CRD and PsycInfo. Study selection Studies were included if meeting the following criteria: reporting empirical results; longitudinal observational design with a minimum of 3 months of follow-up; including general population samples; allowing for the comparison between users and nonusers of e-cigarettes. Studies rated as having high risk of bias were excluded. Studies were independently assessed by at least two authors. The procedures described by PRISMA were followed, and the quality of evidence was rated using GRADE. Data synthesis 30 longitudinal studies from 22 different cohorts assessing e-cigarette use among nonsmokers or never-smokers at baseline, and subsequent use of cigarette smoking at follow-up, were included in this review. A random-effects meta-analysis based on 89076 participants showed a pooled unadjusted odds ratio (OR) of cigarette smoking among baseline nonsmoker e-cigarette users compared with nonusers of 4.68 (CI 3.64-6.02), while the adjusted OR was 3.37 (CI 2.68-4.24). These results were consistent irrespective of whether the outcome was measured as ever-smoking or as past 30-day smoking. The evidence was graded as moderate. Conclusions Use of e-cigarettes may predict the initiation or recurrence of cigarette smoking.
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| 73. |
- Adewumi, Oluwatosin, 1978-, et al.
(författare)
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Corpora Compared : The Case of the Swedish Gigaword & Wikipedia Corpora
- 2020
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Konferensbidrag (refereegranskat)abstract
- In this work, we show that the difference in performance of embeddings from differently sourced data for a given language can be due to other factors besides data size. Natural language processing (NLP) tasks usually perform better with embeddings from bigger corpora. However, broadness of covered domain and noise can play important roles. We evaluate embeddings based on two Swedish corpora: The Gigaword and Wikipedia, in analogy (intrinsic) tests and discover that the embeddings from the Wikipedia corpus generally outperform those from the Gigaword corpus, which is a bigger corpus. Downstream tests will be required to have a definite evaluation.
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| 74. |
- Adewumi, Oluwatosin, 1978-, et al.
(författare)
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Inner For-Loop for Speeding Up Blockchain Mining
- 2020
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Ingår i: Open Computer Science. - Poland : Walter de Gruyter. - 2299-1093. ; 10:1, s. 42-47
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the authors propose to increase the efficiency of blockchain mining by using a population-based approach. Blockchain relies on solving difficult mathematical problems as proof-of-work within a network before blocks are added to the chain. Brute force approach, advocated by some as the fastest algorithm for solving partial hash collisions and implemented in Bitcoin blockchain, implies exhaustive, sequential search. It involves incrementing the nonce (number) of the header by one, then taking a double SHA-256 hash at each instance and comparing it with a target value to ascertain if lower than that target. It excessively consumes both time and power. In this paper, the authors, therefore, suggest using an inner for-loop for the population-based approach. Comparison shows that it’s a slightly faster approach than brute force, with an average speed advantage of about 1.67% or 3,420 iterations per second and 73% of the time performing better. Also, we observed that the more the total particles deployed, the better the performance until a pivotal point. Furthermore, a recommendation on taming the excessive use of power by networks, like Bitcoin’s, by using penalty by consensus is suggested.
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| 75. |
- Adewumi, Oluwatosin, 1978-
(författare)
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Word Vector Representations using Shallow Neural Networks
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This work highlights some important factors for consideration when developing word vector representations and data-driven conversational systems. The neural network methods for creating word embeddings have gained more prominence than their older, count-based counterparts.However, there are still challenges, such as prolonged training time and the need for more data, especially with deep neural networks. Shallow neural networks with lesser depth appear to have the advantage of less complexity, however, they also face challenges, such as sub-optimal combination of hyper-parameters which produce sub-optimal models. This work, therefore, investigates the following research questions: "How importantly do hyper-parameters influence word embeddings’ performance?" and "What factors are important for developing ethical and robust conversational systems?" In answering the questions, various experiments were conducted using different datasets in different studies. The first study investigates, empirically, various hyper-parameter combinations for creating word vectors and their impact on a few natural language processing (NLP) downstream tasks: named entity recognition (NER) and sentiment analysis (SA). The study shows that optimal performance of embeddings for downstream \acrshort{nlp} tasks depends on the task at hand.It also shows that certain combinations give strong performance across the tasks chosen for the study. Furthermore, it shows that reasonably smaller corpora are sufficient or even produce better models in some cases and take less time to train and load. This is important, especially now that environmental considerations play prominent role in ethical research. Subsequent studies build on the findings of the first and explore the hyper-parameter combinations for Swedish and English embeddings for the downstream NER task. The second study presents the new Swedish analogy test set for evaluation of Swedish embeddings. Furthermore, it shows that character n-grams are useful for Swedish, a morphologically rich language. The third study shows that broad coverage of topics in a corpus appears to be important to produce better embeddings and that noise may be helpful in certain instances, though they are generally harmful. Hence, relatively smaller corpus can show better performance than a larger one, as demonstrated in the work with the smaller Swedish Wikipedia corpus against the Swedish Gigaword. The argument is made, in the final study (in answering the second question) from the point of view of the philosophy of science, that the near-elimination of the presence of unwanted bias in training data and the use of foralike the peer-review, conferences, and journals to provide the necessary avenues for criticism and feedback are instrumental for the development of ethical and robust conversational systems.
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| 76. |
- Adewumi, Tosin P., 1978-, et al.
(författare)
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The Challenge of Diacritics in Yorùbá Embeddings
- 2020
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Ingår i: ML4D 2020 Proceedings. - : Neural Information Processing Systems Foundation.
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Konferensbidrag (refereegranskat)abstract
- The major contributions of this work include the empirical establishment of a better performance for Yoruba embeddings from undiacritized (normalized) dataset and provision of new analogy sets for evaluation.The Yoruba language, being a tonal language, utilizes diacritics (tonal marks) in written form. We show that this affects embedding performance by creating embeddings from exactly the same Wikipedia dataset but with the second one normalized to be undiacritized. We further compare average intrinsic performance with two other work (using analogy test set & WordSim) and we obtain the best performance in WordSim and corresponding Spearman correlation.
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| 77. |
- Adewumi, Tosin P., 1978-, et al.
(författare)
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Vector Representations of Idioms in Chatbots
- 2020
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Ingår i: Proceedings. - : Chalmers University of Technology.
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Konferensbidrag (refereegranskat)abstract
- Open-domain chatbots have advanced but still have many gaps. My PhD aims to solve a few of those gaps by creating vector representations of idioms (figures of speech) that will be beneficial to chatbots and natural language processing (NLP), generally. In the process, new, optimal fastText embeddings in Swedish and English have been created and the first Swedish analogy test set, larger than the Google original, for intrinsic evaluation of Swedish embeddings has also been produced. Major milestones have been attained and others are soon to follow. The deliverables of this project will give NLP researchers the opportunity to measure the quality of Swedish embeddings easily and advance state-of-the-art (SotA) in NLP.
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| 78. |
- Adolfsson, Lars, et al.
(författare)
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Union of Scaphoid Waist Fractures in Adults Despite No or Minimal Immobilization : a Report of Five Cases
- 2020
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Ingår i: SN Comprehensive Clinical Medicine. - : Springer. - 2523-8973. ; 2:4, s. 491-495
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Tidskriftsartikel (refereegranskat)abstract
- Traditionally scaphoid waist fractures have been treated with a long period, 10–12 weeks, of immobilization in a plaster cast until radiological union. The long period of immobilization sometimes infers great discomfort for the patients. To avoid this, surgical treatment with screw fixation has for the last decade been advocated as an option also for undisplaced fractures. In this report, we present five cases with undisplaced scaphoid waist fractures that have healed both radiologically and clinically without any immobilization at all or after a very short period of protection in a cast. These observations challenge the current treatment guidelines.
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| 79. |
- Adom, P. K., et al.
(författare)
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Degree of financialization and energy efficiency in Sub-Saharan Africa: do institutions matter?
- 2020
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Ingår i: Financial Innovation. - : Springer Science and Business Media LLC. - 2199-4730. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- The United Nations Sustainable Development Goal 7 emphasizes the need for economies around the world to double their efforts in energy efficiency improvements. This is because improvements in energy efficiency can trigger economic growth and considered as one of the 'green' growth strategies due to its carbon free content. To this end, some empirical studies have investigated the nexus between economic growth and energy efficiency, but the effects of the latter on financial indicators have not been sufficiently studied in the literature, at least in developing economies like Africa. This study examines the effect of energy efficiency improvements on commercial bank profitability under different political regimes (i.e., autocratic and democratic political regimes); something previous literature had neglected. The study uses panel data, consisting of 43 African countries and the simultaneous System Generalized Method of Moments. We found that energy efficiency improvement is more likely to induce higher bank profitability in political institutions with the characteristics of centralization of power compared with those with decentralization of power. Furthermore, for the banking sector, the findings suggest that energy utilization behavior of clients should be included in the loan or credit valuation process. For the government, the agenda of energy efficiency should be aggressively pursued while taking cognizance of creating a political environment that weans itself from a 'grandfathering' behavior.
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| 80. |
- Adom, Philip Kofi, et al.
(författare)
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Energy poverty, development outcomes, and transition to green energy
- 2021
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Ingår i: Renewable Energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 178, s. 1337-1352
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Tidskriftsartikel (refereegranskat)abstract
- There is a close connection between energy and development outcomes. Therefore, energy constraints could adversely influence development outcomes. Consequently, building resilience to energy constraints could be one effective channel to improve development outcomes. This study analyses the effect of energy poverty, while considering the influence of green energy transition, on several development outcomes. Our approach delineates the short and long run dynamics of the net effects of energy poverty and renewable energy transition on development outcomes. First, as a direct effect, we find that energy poverty (renewable energy) has a negative (positive) effect on income, education, life expectancy, employment and mobile phone subscription and a positive (negative) effect on poverty, income inequality, sanitation risk and risk of drinking unsafe water. Conditioning the effect of energy poverty on renewable energy, we find that the transition to green energy partially compensates the adverse effects of energy poverty on the various development outcomes considered in this study. Further, we find that, for several of the development outcomes, the risk of inflated energy cost associated with renewable energy transitions in the short-term is likely to neutralise in the long run, except for income poverty and environmental risk factors. We discuss the policy implications.
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