357 research outputs found

    Strong efficiency improvement of SOI-LEDs through carrier confinement

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    Contemporary silicon light-emitting diodes in silicon-on-insulator (SOI) technology suffer from poor efficiency compared to their bulk-silicon counterparts. In this letter, we present a new device structure where the carrier injection takes place through silicon slabs of only a few nanometer thick. Its external quantum efficiency of 1.4 • 10−4 at room temperature, with a spectrum peaking at 1130 nm, is almost two orders higher than reported thus far on SOI. The structure diminishes the dominant role of nonradiative recombination at the n+ and p+contacts, by confining the injected carriers in an SOI peninsula.\ud With this approach, a compact infrared light source can be fabricated using standard semiconductor processing steps.\u

    Open and Notorious: Adverse Possession and Immigration Reform

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    We suggest that there are reasons to support the patriation of undocumented immigrants without invoking sentimentality, generosity or amnesty, all of which tend to elicit commensurate sanctions and indignance. Instead, we want to confront directly the seemingly airtight presumption of illegality. We will depend in our argument upon a concept in property law. The concept is adverse possession, and in some form or other, it exists in most legal systems throughout the world. Simply put, adverse possession allows a proprietary claim to individuals who have occupied property that is not initially theirs. We will show how the concept of adverse possession can assist immigration progressives to face the legality issue rather than sidestep it, in so doing strengthen the argument for a humane and rational immigration policy

    Energy harvesting over Rician fading channel: A performance analysis for half-duplex bidirectional sensor networks under hardware impairments

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    In this paper, a rigorous analysis of the performance of time-switching energy harvesting strategy that is applied for a half-duplex bidirectional wireless sensor network with intermediate relay over a Rician fading channel is presented to provide the exact-form expressions of the outage probability, achievable throughput and the symbol-error-rate (SER) of the system under the hardware impairment condition. Using the proposed probabilistic models for wireless channels between mobile nodes as well as for the hardware noises, we derive the outage probability of the system, and then the throughput and SER can be obtained as a result. Both exact analysis and asymptotic analysis at high signal-power-to-noise-ratio regime are provided. Monte Carlo simulation is also conducted to verify the analysis. This work confirms the effectiveness of energy harvesting applied in wireless sensor networks over a Rician fading channel, and can provide an insightful understanding about the effect of various parameters on the system performance.Web of Science186art. no. 1781

    Artificial intelligent based teaching and learning approaches: A comprehensive review

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    The goal of this study is to investigate the potential effects that Artificial intelligence (AI) could have on education. The narrative and framework for investigating AI that emerged from the preliminary research served as the basis for the study’s emphasis, which was narrowed down to the use of AI and its effects on administration, instruction, and student learning. According to the findings, artificial intelligence has seen widespread adoption and use in education, particularly by educational institutions and in various contexts and applications. The development of AI began with computers and technologies related to computers; it then progressed to web-based and online intelligent education systems; and finally, it applied embedded computer systems in conjunction with other technologies, humanoid robots, and web-based chatbots to execute instructor tasks and functions either independently or in partnership with instructors. By utilizing these platforms, educators have been able to accomplish a variety of administrative tasks. In addition, because the systems rely on machine learning and flexibility, the curriculum and content have been modified to match the needs of students. This has led to improved learning outcomes in the form of higher uptake and retention rates

    Two-way half duplex decode and forward relaying network with hardware impairment over Rician fading channel: system performance analysis

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    In this paper, the system performance analysis of a two-way decode and forward (DF) relaying network over the Rician fading environment under hardware impairment effect is proposed, analyzed and demonstrated. In this analysis, the analytical mathematical expressions of the achievable throughput, the outage probability, and ergodic capacity were proposed, analyzed and demonstrated. After that, the effect of various system parameters on the system performance is deeply studied with closed-form expressions for the system performance. Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the closed-form expressions. The numerical results demonstrated and convinced the effect of the system parameters on the system performance of the two-way DF relaying network. The results show that the analytical mathematical and simulated results match for all possible parameter values.Web of Science242787

    A Text-based Approach For Link Prediction on Wikipedia Articles

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    This paper present our work in the DSAA 2023 Challenge about Link Prediction for Wikipedia Articles. We use traditional machine learning models with POS tags (part-of-speech tags) features extracted from text to train the classification model for predicting whether two nodes has the link. Then, we use these tags to test on various machine learning models. We obtained the results by F1 score at 0.99999 and got 7th place in the competition. Our source code is publicly available at this link: https://github.com/Tam1032/DSAA2023-Challenge-Link-prediction-DS-UIT_SATComment: Accepted by DSAA 2023 Conference in the DSAA Student Competition Sectio

    On how religions could accidentally incite lies and violence: folktales as a cultural transmitter

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    Folklore has a critical role as a cultural transmitter, all the while being a socially accepted medium for the expressions of culturally contradicting wishes and conducts. In this study of Vietnamese folktales, through the use of Bayesian multilevel modeling and the Markov chain Monte Carlo technique, we offer empirical evidence for how the interplay between religious teachings (Confucianism, Buddhism, and Taoism) and deviant behaviors (lying and violence) could affect a folktale’s outcome. The findings indicate that characters who lie and/or commit violent acts tend to have bad endings, as intuition would dictate, but when they are associated with any of the above Three Teachings, the final endings may vary. Positive outcomes are seen in cases where characters associated with Confucianism lie and characters associated with Buddhism act violently. The results supplement the worldwide literature on discrepancies between folklore and real-life conduct, as well as on the contradictory human behaviors vis-à-vis religious teachings. Overall, the study highlights the complexity of human decision-making, especially beyond the folklore realm

    Adjustment of Vietnamese labour market in time of economic fluctuations and structural changes

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    Dans cet article, nous examinons les ajustements du marché du travail aux fluctuations économiques, compte tenu des transformations structurelles en cours ainsi que des changements à court terme. Nous utilisons pour cela des données des recensements de la population ou publiées dans les annuaires statistiques de l’Office Général de la Statistique pour les séries à long terme, et les enquêtes emploi conduites entre 2007 à 2012 pour les données à court terme. Cet article souligne la profonde transformation du marché du travail au cours des dernières décennies. La population active a doublé en 25 ans et la part de l'agriculture est passée en dessous du seuil de 50 %. L’absorption de l'offre de travail a donc été l'un des principaux défis pour l'économie vietnamienne sur cette période. Le secteur des entreprises familiales agricoles et non-agricoles a été le principal pourvoyeur d'emplois au cours de ces années. Le marché du travail s'est adapté au récent ralentissement économique à travers différents canaux. Le chômage est resté stable mais le nombre de personnes inactives a augmenté. La quantité de travail a également été affectée par une réduction significative du nombre d'heures travaillées. Alors que le secteur non agricole a généré plus d'emplois pour les travailleurs qualifiés, un flux de travailleurs non-qualifiés vers l’agriculture a été observé. En raison de facteurs démographiques, l'absorption de l'offre de travail et la création de nouveaux emplois ne sont plus le principal problème. En revanche, l’évolution récente du marché du travail appelle à la mise en oeuvre de politiques structurelles en vue d’améliorer les conditions de travail, la période étant particulièrement favorable pour mener ces politiques puisque le Vietnam profite actuellement du dividende démographique
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