4,896 research outputs found

    Designing learning activities to develop self-directed learning competency in teaching informatics

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    Currently, there are not many studies on teaching informatics in the direction of developing students鈥 self-directed learning (SDL) competency. The results of the survey with 235 informatics teachers in 42 provinces/cities across Vietnam showed that although they are very interested in teaching SDL, teachers are still confused about teaching methods and assessments. To improve the effectiveness of informatics teaching as well as develop SDL for students, the study proposed a method of teaching informatics in the direction of designing activities to guide students to create digital products by themselves. The pedagogical experiment on assessing SDL and learning outcomes was conducted on two experimental and control groups, selected from 87 10th grade students, in the first semester of the school year 2022-2023 at Cam Giang High school in Hai Duong, Vietnam. The results of SDL and test scores of the experimental class were higher than that of the control class (with p-value <0.005鈥 this difference is statistically significant). This proves that the method (creating of digital products) is effective, positively affecting students鈥 learning, helping students develop SDL competency

    Automatic History Matching for Adjusting Permeability Field of Fractured Basement Reservoir Simulation Model Using Seismic, Well Log, and Production Data

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    Developing automatic history matching (AHM) methods to replace the traditional manual history matching (MHM) approach in adjusting the permeability distribution of the reservoir simulation model has been studied by many authors. Because permeability values need to be evaluated at hundreds of thousands of grid cells in a typical reservoir simulation model, it is necessary to apply a reparameterization technique to allow the optimization algorithms to be implemented with fewer variables. In basic reparameterization techniques including zonation and pilot point methods, the calibrations are usually based solely on the production data with no systematic link to the geological and geophysical data, and therefore, the obtained permeability distribution may be not geologically consistent. Several other reparameterization techniques have attempted to preserve geological consistency by incorporating 4D seismic data; however, these techniques cannot be applied to our fractured basement reservoirs (FBRs) as they do not have 4D seismic data. Taking into account these challenges, in this study, an AHM methodology and workflow have been developed using a new reparameterization technique. This approach attempts to minimize the potential for geological nonconsistency of the calibrated results by linking the permeability to geophysical data. The proposed methodology can be applied to fields with only traditional geophysical data (3D seismic and conventional well logs). In the proposed workflow, the spatial distributions of seismic attributes and geomechanical properties were calculated and estimated from 3D seismic data and well logs, respectively. After that, a feed-forward artificial neural network (ANN) model trained by the back-propagation algorithm of the relationship between initial permeability with seismic attributes and geomechanical properties of their grid cell values is developed. Then, the calibration of the permeability distribution is performed by adjustment of the ANN model. Modification of the ANN model is performed using the simultaneous perturbation stochastic approximation (SPSA) algorithm to calibrate transmission coefficients in the ANN model to minimize the discrepancy between the simulated results and observed data. The developed methodology is applied to calibrate the permeability distribution of a simulation model of Bach Ho FBR in Vietnam. The effectiveness of the methodology is evident by comparing the historical matches with an available manually history-matched simulation model. The application shows that the proposed methodology could be considered as a suitable practical approach for adjusting the permeability distribution for FBR reservoir simulation models

    Useful treatment paradigms: Decompressive hemicraniectomy with hematoma evacuation in larger intracranial hemorrhage. Insights from a leading vietnamese hospital

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    Background and Purpose: Spontaneous intracerebral hemorrhage (SICH) bears a poor prognosis, with a 30-day mortality rate of 35%鈥52%. The mass effects of hematoma and surrounding edema in larger supratentorial SICH lead to an increased intracranial pressure (ICP) and subsequent brain herniation. Multiple trials have failed to prove the superiority of surgical evacuation over conservative methods. However, surgery in a carefully selected set of patients is beneficial in reducing mortality and limiting disability. The aim of this study was to investigate the effectiveness of decompressive hemicraniectomy (DHC) with hematoma evacuation for treating patients with larger supratentorial SICH. Methods: This was a retrospective study conducted at our hospital between December 2016 and April 2020. A total of 55 patients with large supratentorial SICH treated with DHC and hematoma evacuation during this period. Patient characteristics and clinical information were analyzed, including age, sex, Glasgow Coma Scale (GCS), stroke severity (e.g. National Institutes of Health Stroke Scale), computed tomography (CT) scan data (signs of herniation, side and size of hematoma, midline shift), the time interval between ictus and surgery, surgical characteristics, and time of ventilation. Outcome was assessed by modified Rankin Scale (mRS) at six months after surgery. Results: Fifty-five patients (82% males) were treated with DHC. The mean age was 55聽years. The median NIHSS (National Institutes of Health Stroke Scale) score at admission was 26 (range 9鈥32). Approximately two-thirds of the patients (69.1%) had hematoma located within the basal ganglia, while 30.9% had lobar hematomas. The median midline shift was 10.9聽mm (range 4鈥20聽mm). Intraventricular extensions were observed in 23 patients on the pre-operative CT scan. At discharge, the median mRS score was 5 (range 4鈥6), and 5 patients (9.1%) died. Six months after surgery, 17 patients (31%) had favorable outcomes (mRS scores 0鈥3), while the remaining patients had poor outcomes (mRS scores 4鈥6). The mortality rate was 25.5% (n聽=聽14 patients). In comparison to the poor outcome group, those with favorable outcomes had a significantly higher GCS score (mean, 9.5 [SD聽=聽2.5] vs 8.0 [SD聽=聽1.9]; p聽=聽0.013). Conversely, those who had poor outcomes were more likely to be older (mean 57.2 [SD聽=聽10.4] vs 49.7 [SD聽=聽10.7]; p聽=聽0.017) and had a larger hematoma volume (mean 95.8 [SD聽=聽32] vs 71.6 [SD聽=聽33.0]; p聽=聽0.018). Conclusions: Decompressive hemicraniectomy with hematoma evacuation could be beneficial for a selected group of young patients with large SICH

    Acceptance and User Experiences of a Wearable Device for the Management of Hospitalized Patients in COVID-19鈥揇esignated Wards in Ho Chi Minh City, Vietnam: Action Learning Project

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    BackgroundWearable devices have been used extensively both inside and outside of the hospital setting. During the COVID-19 pandemic, in some contexts, there was an increased need to remotely monitor pulse and saturated oxygen for patients due to the lack of staff and bedside monitors. ObjectiveA prototype of a remote monitoring system using wearable pulse oximeter devices was implemented at the Hospital for Tropical Diseases in Ho Chi Minh City, Vietnam, from August to December 2021. The aim of this work was to support the ongoing implementation of the remote monitoring system. MethodsWe used an action learning approach with rapid pragmatic methods, including informal discussions and observations as well as a feedback survey form designed based on the technology acceptance model to assess the use and acceptability of the system. Based on these results, we facilitated a meeting using user-centered design principles to explore user needs and ideas about its development in more detail. ResultsIn total, 21 users filled in the feedback form. The mean technology acceptance model scores ranged from 3.5 (for perceived ease of use) to 4.4 (for attitude) with behavioral intention (3.8) and perceived usefulness (4.2) scoring in between. Those working as nurses scored higher on perceived usefulness, attitude, and behavioral intention than did physicians. Based on informal discussions, we realized there was a mismatch between how we (ie, the research team) and the ward teams perceived the use and wider purpose of the technology. ConclusionsDesigning and implementing the devices to be more nurse-centric from their introduction could have helped to increase their efficiency and use during the complex pandemic period

    One-stage reconstruction of the massive overlying skin defect combined with total loss of extensor tendon in zones V and VI using a reverse pedicled radial forearm tendinocutaneous flap: A case report

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    Our case report involved a 36-year-old man who sustained injury during manual labor caused by a machine press. The patient had extensive fourth-degree burns in the right dorsal hand with total loss of extensor tendons in zones V and VI of the index, middle, and ring finger. We performed a reverse radial forearm tendinocutaneous flap (the radial artery flap permits the inclusion of three 鈥渟trips鈥 of vascularized tendons: brachioradialis, flexor carpi radialis, and palmaris longus) to cover his hand defects. Six months after the operation, the active extension of the index, middle, and ring metacarpophalangeal joints had recovered well. The patient is satisfied with the outcome

    Enhancing Indoor Robot Pedestrian Detection Using Improved PIXOR Backbone and Gaussian Heatmap Regression in 3D LiDAR Point Clouds

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    Accurate and robust pedestrian detection is fundamental for indoor robotic systems to navigate safely and seamlessly alongside humans in spatially constrained, unpredictable indoor environments. This paper presents a novel method, IRBGHR-PIXOR, a detection framework specifically engineered for pedestrian perception in indoor mobile robots. This novel approach employs an enhanced adaptation of the cutting-edge PIXOR model, integrating two pivotal augmentations: a remodeled convolutional backbone leveraging Inverted Residual Blocks (IRB) in unison with Gaussian Heatmap Regression (GHR), as well as a Modified Focal Loss (MFL) function to tackle data imbalance issues. The IRB component notably bolsters the network’s aptitude for processing intricate spatial representations generated from sparse 3D LiDAR scans. Meanwhile, integrating GHR further elevates accuracy by enabling precise localization of pedestrian subjects. This is achieved by modeling the probability distribution and predicting the central location of individuals in the point cloud data. Extensively evaluated on the large-scale JRDB dataset comprising intense scans from 16-beam Velodyne LiDAR sensors, IRBGHR-PIXOR accomplishes exceptional results, attaining 97.17% Average Precision (AP) at the 0.5 IOU threshold. Notably, this level of accuracy is achieved without significantly increasing model complexity. By enhancing algorithms to overcome challenges in confined indoor environments, this research paves the way for safe and effective deployment of autonomous technologies once encumbered by perceptual limitations in human-centered spaces. Nonetheless, evaluating performance in diverse edge cases and integration with complementary sensory cues promise continued progress. The developments contribute towards the vital capacity of reliable dynamic perception for next-generation robotic systems coexisting in human-centric environments

    Engineering functionalized Zr-MOFs as facile removal of indole: Experimental studies and first-principles modeling

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    Zr-based metal-organic frameworks (Zr-MOFs) are emerging as potential adsorbents for removing nitrogen contaminants in fuel and wastewater. Functionalized Zr-MOFs exhibited superior indole (IND) adsorption capacity than the original MOF, but the activity of the multiple adsorption sites has not been discussed. Through experiment measurement and Density Functional Theory (DFT) calculations, this research investigated the IND adsorption mechanism at various sites on Zr-BDC-NH2 and Zr-BDC-NO2. Based on the adsorption isotherm, the adhesion of IND with Zr-MOFs was determined via the Freundlich model. DFT results suggest that the IND adsorption occurred at highly active sites such as O-linker, 渭3-O-cluster, N-amine, and O-nitro via hydrogen and 蟺-hydrogen bonds. Furthermore, the binding energy at each adsorption site in Zr-BDC-NH2 is higher than in Zr-BDC-NO2. In addition to the hydrogen acceptor bond, the 蟺-hydrogen bond has also been analyzed through the electron density difference

    Solid-state crystallization, oxygen-vacancy rich mesopores and stable triad-silanol nests in ZSM-5 catalyst induced by electron-beam irradiation and calcination

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    Mesopores and silanol nests are known two technological keys that essentially control the catalytic performance of ZSM-5 zeolite. However, designing and controlling them without using chemicals so that the produced ZSM-5 can have strongly enhanced catalytic properties and more importantly can be applied at industrial scale have still been a big challenge up to now. The present study employed the 10 MeV electron beam (EB) generated from an industrial linear accelerator to introduce both the O-vacancy rich mesopores and stable triad-silanol nests in ZSM-5. The structural modification of irradiated ZSM-5 samples was explored by using SEM and FTIR combined with positron annihilation spectroscopy (PAS) including positron annihilation lifetime (PAL), Doppler broadening (DB) of electron鈥損ositron annihilation energy and electron momentum distribution (EMD). Obtained results indicated that EB irradiation could recover the defective-crystal structure as well as intensively modify the structures of ZSM-5. In particular, the mechanism for the solid-state crystallization and the formation of the O-vacancy rich mesopores (maximum size of 鈭4.5 nm) in ZSM-5 under the combined EB irradiation (10鈭110 kGy) and calcination (600 掳C) was, for the first time, proposed. The mechanism for the formation of stable triad-silanol nests in the channels of irradiated and calcined ZSM-5 zeolites was also explored. The present study, therefore, opens a new research path of applying both EB irradiation and calcination to produce ZSM-5 with novel features for industrial catalytic application at large-production scale