1,048 research outputs found

    A Bandit Approach to Online Pricing for Heterogeneous Edge Resource Allocation

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    Edge Computing (EC) offers a superior user experience by positioning cloud resources in close proximity to end users. The challenge of allocating edge resources efficiently while maximizing profit for the EC platform remains a sophisticated problem, especially with the added complexity of the online arrival of resource requests. To address this challenge, we propose to cast the problem as a multi-armed bandit problem and develop two novel online pricing mechanisms, the Kullback-Leibler Upper Confidence Bound (KL-UCB) algorithm and the Min-Max Optimal algorithm, for heterogeneous edge resource allocation. These mechanisms operate in real-time and do not require prior knowledge of demand distribution, which can be difficult to obtain in practice. The proposed posted pricing schemes allow users to select and pay for their preferred resources, with the platform dynamically adjusting resource prices based on observed historical data. Numerical results show the advantages of the proposed mechanisms compared to several benchmark schemes derived from traditional bandit algorithms, including the Epsilon-Greedy, basic UCB, and Thompson Sampling algorithms

    Synthesis and Photocatalytic Activity for Toluene Removal of CDs/TiO2 - Zeolite Y

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    Hydrothermally synthesized carbon nanodots (CDs) were impregnated on TiO2. The product (CDs/TiO2) was mechanically mixed with zeolite Y for application in toluene photocatalytic oxidation reaction under UV radiation. Material properties of the samples were investigated by different methods. Toluene vapor was chosen as a typical volatile organic compound to investigate the performance of CDs/TiO2 – zeolite Y photocatalyst when these technological parameters were changed: toluene concentration, gas flow rate, humidity and UV light intensity. In each reaction, only one parameter was changed and the remaining conditions were fixed. The toluene concentrations at the beginning and the end of each reaction were analyzed with the use of gas chromatography (GC). The results of different reaction conditions show the trends for toluene treatment of the CDs/TiO2 – zeolite Y catalyst, thereby providing specific explanations for these trends. The experiments also show that toluene removal is highest when the toluene concentration in the inlet gas is 314 ppmv, the flow rate is 3 L/h, the humidity is 60%, and the catalyst (CDs/TiO2 – zeolite Y composite with 70% zeolite in weight) is illuminated by 4 UV lamps. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

    Vietnam's visa policy for tourists

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    States employ travel visa as an instrument to leverage on visitor arrivals for various reasons. In tourism, visa plays a crucial role in facilitating potential and last-minute tourists’ decision making process. This paper focuses on the Vietnamese government’s visa policy in the context of tourism development. Adopting an economic approach, this paper reviews key achievements in tourist immigration policies and examines the challenges that deter tourists from visiting the country. This study purports that a stronger national strategy pertaining to simplification of visa processing and streamlining common visa entry union with neighboring countries within the AEC 2015 framework will translate to gains for Vietnamese tourism. __________________________________________________ Key words: economic approach, national visa policy, tourism developmen

    Validity of two physical activity questionnaires (IPAQ and PAQA) for Vietnamese adolescents in rural and urban areas

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    <p>Abstract</p> <p>Background</p> <p>Although physical activity is recognised to be an important determinant of health and nutritional status, few instruments have been developed to assess physical activity in developing countries. The aim of this study was to compare the validity of the short form of the International Physical Activity Questionnaire (IPAQ) and a locally adapted version of the Physical Activity Questionnaire for Adolescents (PAQA) for use in school going adolescents in rural and urban areas in Vietnam.</p> <p>Methods</p> <p>Sixteen year old adolescents from rural areas (n = 137) and urban areas (n = 90) completed the questionnaires in 2006. Test-retest reliability was assessed by comparing registrations after 2 weeks. Criterion validity was assessed by comparison with 7 days continuous accelerometer logging. Validity of the two methods was assessed using Spearman correlation coefficient, intra class correlation coefficients (ICC) and Kappa statistics.</p> <p>Results</p> <p>Reliability of both questionnaires was poor for both the IPAQ (ICC = 0.37) and the PAQA (ICC = 0.40). Criterion validity of both questionnaires was acceptable and similar for the IPAQ (ρ = 0.21) and the PAQA (ρ = 0.27) but a significantly lower validity was observed in rural areas. Both forms poorly estimated time spent on light, moderate and vigorous physical activity. Agreement of both questionnaires to classify individuals was also low but the IPAQ performed better than the PAQA.</p> <p>Conclusion</p> <p>Both questionnaires have a similar and overall poor validity to be used as a population instrument in Vietnam. Low reliability and classification properties in rural areas call for further research for specific use in such settings.</p

    Factors influencing to use of Bluezone

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    This study aims to understand the main factors and their influence on the behavioral intention of users about using Bluezone. Surveys are sent to users through the Google Form tool. Experimental results through analysis of exploratory factors on 224 survey subjects show that there are 4 main factors affecting user behavior. Structural equation modeling indicates that trust, performance expectations, effort expectations, and social influence have a positive impact on behavioral intention of using BluezoneComment: in Vietnamese languag

    Drug-Related Problems in Prescribing for Pediatric Outpatients in Vietnam

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    BACKGROUND: Our study was conducted to determine the prevalence of drug-related problems (DRPs) in outpatient prescriptions, the impact of DRPs on treatment efficacy, safety, and cost, and the determinants of DRPs in prescribing for pediatric outpatients in Vietnam. METHODS: A retrospective cross-sectional study was conducted on pediatric outpatients at a pediatric hospital in Can Tho, Vietnam. DRPs were classified according to the Pharmaceutical Care Network Europe classification (PCNE) of 2020. The study determined prevalence of DRPs and their impacts on efficacy, safety, and cost. Multivariate regression was used to identify the determinants of DRPs. RESULTS: The study included 4339 patients (mean age 4.3, 55.8% male), with a total of 3994 DRPs, averaging 0.92 DRP/prescription. The proportion of prescriptions with at least one DRP was 65.7%. DRPs included inappropriate drug selection (35.6%), wrong time of dosing relative to meals (35.6%), inappropriate dosage form (9.3%), inappropriate indication (7.1%), and drug-drug interactions (0.3%). The consensus of experts was average when evaluating each aspect of efficiency reduction, safety reduction, and treatment cost increase, with Fleiss' coefficients of 0.558, 0.511, and 0.541, respectively (p < 0.001). Regarding prescriptions, 50.1% were assessed as reducing safety. The figures for increased costs and decreased treatment effectiveness were 29.0% and 23.9%, respectively. Patients who were ≤2 years old were more likely to have DRPs than patients aged 2 to 6 years old (OR = 0.696; 95% CI = 0.599-0.809) and patients aged over 6 years old (OR = 0.801; 95% CI = 0.672-0.955). Patients who had respiratory system disease were more likely to have DRPs than patients suffering from other diseases (OR = 0.715; 95% CI = 0.607-0.843). Patients with comorbidities were less likely to have DRPs than patients with no comorbidities (OR = 1.421; 95% CI = 1.219-1.655). Patients prescribed ≥5 drugs were more likely to have DRPs than patients who took fewer drugs (OR = 3.677; 95% CI = 2.907-4.650). CONCLUSION: The proportion of prescriptions in at least one DRP was quite high. Further studies should evaluate clinical significance and appropriate interventions, such as providing drug information and consulting doctors about DRPs

    Temporal and spatial transcriptional regulation of phytohormone metabolism during seed development in barley (Hordeum vulgare L.)

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    Plant hormones play important roles in seed development; however, transcriptional regulation of their metabolism and levels of the respective bioactive forms during barley seed development is poorly understood. To this end, this study performed a comprehensive analysis of changes in the expression patterns phytohormone metabolism genes and levels of the respective bioactive forms in the embryo and endosperm tissues. Our study showed the presence of elevated levels of abscisic acid (ABA), bioactive forms of gibberellins (GAs), jasmonate (JA) and cytokinins (CKs), auxin and salicylic acid (SA) in the endosperm and embryo tissues at early stage of seed filling (SF). The levels of all hormones in both tissues, except that of ABA, decreased to low levels during SF. In contrast, embryonic ABA level increased during SF and peaked at physiological maturity (PM) while the endospermic ABA was maintained at a similar level observed during SF. Although its level decreased high amount of ABA was still present in the embryo during post-PM. We detected low levels of ABA in the endosperm and all the other hormones in both tissues during post-PM phase except the relatively higher levels of jasmonoyl-isoleucine and SA detected at late stage of post-PM. Our data also showed that spatiotemporal changes in the levels of plant hormones during barley seed development are mediated by the expression of specific genes involved in their respective metabolic pathways. These results indicate that seed development in barley is mediated by spatiotemporal modulation in the metabolism and levels of plant hormones

    Anatomy of autoantibody production: Dominant localization of antibody-producing cells to T cell zones in fas-deficient mice

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    AbstractThe goal of this study was to examine the in vivo site of autoantibody production in normal and autoimmune-prone mice. B cells were identified in tissue sections with IgM- and IgG2a-specific riboprobes that readily distinguished resting cells from antibody-forming cells (AFC). In normal mice, the few identifiable IgG2a-secreting cells were found in the red pulp. By contrast, in Ipr mice exceedingly high numbers of IgG2a and autoantibody-producing cells were found deep within the T cell-rich periarteriolar lymphoid sheaths (PALS). This unusual anatomic location of autoantibody-secreting B cells is unique to Fas dysregulated strains, since IgG2a-producing cells in MRL/+ and (SWR × NZB)F1 mice were found predominantly in the red pulp or outer PALS, similar to normal mice. Furthermore, analysis of spleens from Ipr and non-Ipr anti-DNA immunoglobulin transgenic mice revealed dramatic accumulation of Tg+ cells in the inner PALS only in Ipr mice. These data suggest that in the absence of Fas, autoreactive B cells accumulate in T cell-rich zones, and this anatomic feature may contribute to autoantibody production

    UIT-Saviors at MEDVQA-GI 2023: Improving Multimodal Learning with Image Enhancement for Gastrointestinal Visual Question Answering

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    In recent years, artificial intelligence has played an important role in medicine and disease diagnosis, with many applications to be mentioned, one of which is Medical Visual Question Answering (MedVQA). By combining computer vision and natural language processing, MedVQA systems can assist experts in extracting relevant information from medical image based on a given question and providing precise diagnostic answers. The ImageCLEFmed-MEDVQA-GI-2023 challenge carried out visual question answering task in the gastrointestinal domain, which includes gastroscopy and colonoscopy images. Our team approached Task 1 of the challenge by proposing a multimodal learning method with image enhancement to improve the VQA performance on gastrointestinal images. The multimodal architecture is set up with BERT encoder and different pre-trained vision models based on convolutional neural network (CNN) and Transformer architecture for features extraction from question and endoscopy image. The result of this study highlights the dominance of Transformer-based vision models over the CNNs and demonstrates the effectiveness of the image enhancement process, with six out of the eight vision models achieving better F1-Score. Our best method, which takes advantages of BERT+BEiT fusion and image enhancement, achieves up to 87.25% accuracy and 91.85% F1-Score on the development test set, while also producing good result on the private test set with accuracy of 82.01%.Comment: ImageCLEF2023 published version: https://ceur-ws.org/Vol-3497/paper-129.pd
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