321 research outputs found

    Effects of Data Standardization on Hyperparameter Optimization with the Grid Search Algorithm Based on Deep Learning: A Case Study of Electric Load Forecasting

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    This study investigates data standardization methods based on the grid search (GS) algorithm for energy load forecasting, including zero-mean, min-max, max, decimal, sigmoid, softmax, median, and robust, to determine the hyperparameters of deep learning (DL) models. The considered DL models are the convolutional neural network (CNN) and long short-term memory network (LSTMN). The procedure is made over (i) setting the configuration for CNN and LSTMN, (ii) establishing the hyperparameter values of CNN and LSTMN models based on epoch, batch, optimizer, dropout, filters, and kernel, (iii) using eight data standardization methods to standardize the input data, and (iv) using the GS algorithm to search the optimal hyperparameters based on the mean absolute error (MAE) and mean absolute percent error (MAPE) indexes. The effectiveness of the proposed method is verified on the power load data of the Australian state of Queensland and Vietnamese Ho Chi Minh city. The simulation results show that the proposed data standardization methods are appropriate, except for the zero-mean and min-max methods

    Building a Conceptual Framework for Using Big Data Analytics in the Banking Sector

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    CC BY-NC-ND 4.0Big Data and Big Data Analytics (BDA) are becoming trending technologies of the future. This topic has garnered considerable interest from researchers and businesses. However, BDA research in the banking sector has proven to be extremely limited and mixed. Addressing the challenges of BDA application and laying the foundation for BDA to improve banking efficiency raises significant questions about strategic management in the banking sector. Through a systematic review of the literature and a case study in Hungarian banks, this study intends to address the major inconsistencies in existing ideas about BDA applications. This study also proposes a conceptual model to evaluate the impact of factors influencing the use of BDA in the banking sector and investigates whether BDA affects the performance of banks. Our study finds that the use of BDA in the banking sector has to be aligned with the creation of dynamic capabilities that positively and directly affect banking in terms of the market and operational performance. Meanwhile, the dynamic capabilities created by BDA usage have a moderating impact on bank performance through improved risk management performance. Furthermore, this research helps managers focus on key factors, namely technological infrastructures, Big Data skills, data quality, and top management support, to boost the efficiency of using BDA

    PURIFICATION OF PHOSPHOGYPSUM FOR USE AS CEMENT RETARDER BY SULPHURIC ACID TREATMENT

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    Phosphogypsum is a by-product of the wet phosphoric acid production. In this study, chemical compositions of phosphogypsum waste (PG) in Hai Phong diammonium phosphate plant (DAP1) and Lao Cai diammonium phosphate plant (DAP2) in Vietnam were surveyed for the purpose of gypsum recovery by P2O5, F removal to meet TCVN11833 for use treated gypsum as cement retarder. Studies of impurities P2O5, F, TOC removal by sulfuric acid 10 % at 28 0C was presented. The results found that the combination of a low concentration of sulfuric acid treatment, washing, lime neutralizing, and thermal treatment was successful in Phoshogypsum treatment for use as cement retarder. The cement test proved that treated PG could partially replace natural gypsum as a retarder.Keywords:  phosphogypsum treatment, phosphorus pentoxide removal, calcium sulfate transition phase, cement retarder.

    Microfluidic Chip for Trapping Magnetic Nanoparticles and Heating in Terms of Biological Analysis

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    In this study, we reported the results of the design and the fabrication a planar coil in copper (square, a = 10 mm, 15mm high, 90 turns), these planar coils were integrated in a microfluidic chip for trapping magnetic nanoparticles and local heating applications. A small thermocouple (type K, 1 mm tip size) was put directly on top of the micro-channel in poly(dimethyl-siloxane) in order to measure the temperature inside the channel during applying current. The design of planar coils was based on optimizing the results of the magnetic calculation. The most suitable value of the magnetic field generated by the coil was calculated by ANSYS® software corresponded to the different distances from the coil surface to the micro-channel bottom (magnetic field strength Hmax = 825 A/m). The magnetic filed and heating relationship was balanced in order to manipulating the trapping magnetic nanoparticles and heating process. This design of the microfluidic chip can be used to develop a complex microfluidic chip using magnetic nanoparticles

    Digital Economy: A Comparative Study in ASEAN

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    Current medical product development for diagnosis, surgical planning and treatment in the areas of Neurosurgery, Orthopeadic and Dental-Cranio-Maxillofacial surgery in Vietnam

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    With the population of 86 million and good GDP growth in recent decades, the medical market in Vietnam is growing fast. However, most of the medical technology products are imported, and the number of locally manufactured ones is limited and they do not have the high competition capability in term of quality, quantity and types. In this paper, the current product development in Vietnam for diagnosis, surgical planning and treatment in the areas of Rehabilitation, Neurosurgery, Orthopeadic and Dental-Cranio-Maxillofacial surgery is presented. A roadmap for medical technology development in Vietnam is propose

    Effect of Polypyrrole on the Electrical, Dielectric and Mechanical Properties of Waterborne Epoxy Coatings

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    In this context, conducting composite based on waterborne epoxy system and polypyrrole (PPy) was investigated. The polypyrrole was synthesized by chemical oxidation polymerization. Its morphology and chemical structure were confirmed by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Then, PPy was well-dispersed in the epoxy coating and had a good compatibility with the matrix. The effects of PPy on dielectric, electrical and mechanical properties of epoxy/PPy composites was examined. The dielectric constant and electrical conductivity of the coatings increased with addition of PPy fillers. Over to 15 wt. % of PPy loading, the volume resistivity of samples slightly decreased from 6.7 × 1010 to 1.5 × 1010 Ω cm. In contrast, the presence of PPy diminished both impact and abrasion resistance of the epoxy/PPy composites, down to 160 kg cm and 10.2 L/mil, respectively, but they stayed acceptable for the coatings. The results reveal that the epoxy containing polypyrrole is suitable for various electrical and dielectric applications

    Electrosynthesis of a poly(1,5-diaminonaphthalene) - polypyrrole nanowire bilayer for trichlorfon insecticide biosensing

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    In this study, an acetylcholinesterase enzyme biosensor was developed based on a bilayer of poly(1,5-diaminonaphthalene) and polypyrrole nanowire structures modifying carbon screen-printed electrodes (SPEs). A polypyrrole nanowire inner layer was electrodeposited on the surface of SPEs to enhance conductivity and specific areas. A poly(1,5-diaminonaphthalene) outer layer was used for immobilizing acetylcholinesterase through glutaraldehyde agent. On the basis of the inhibition of organophosphate pesticides on the enzymatic activity of acetylcholinesterase enzyme, the acetylcholinesterase-immobilized bilayer of the conductive polymer electrode was designed for electrochemical determination of trichlorfon insecticide, one of the popular organophosphate pesticides. Keywords. Acetylcholinesterase, biosensors, poly(1,5-diaminonaphthalene), polypyrrole nanowire, trichlorfon

    Insight into the effect of zinc oxide nanoparticles coated multi-walled carbon nanotubes (ZnO/MWCNTs) on the thermal conductivity of epoxy nanocomposite as an electrical-insulating coating

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    The effect of zinc oxide (ZnO) nanoparticles on the thermal conductivity of zinc oxide/multi-walled carbon nanotubes (ZnO/MWCNTs) nanocomposite electrical-insulating coating was investigated. ZnO/MWCNTs was prepared by sol–gel method and incorporated into the epoxy matrix by ultrasonic-mechanical mixing to form the nanocomposite (ZnO/MWCNTs/epoxy). The SEM, XRD, and TGA analysis results showed that ZnO nanoparticles with 3–4 nm size formed layers on MWCNTs wires with a 10-nm diameter. The formed ZnO/CNT nanofillers had a diameter about 20–40 nm and had a highly homogeneous dispersion in the epoxy matrix. The thermal property of the nanocomposites was examined by the thermal imaging method. It was found that both MWCNTs and ZnO/MWCNTs nanofillers have significantly enhanced the thermal conduction of composites even at a low content load of 0.25 wt%. The thermal conductivity of ZnO/MWCNTs/epoxy and MWCNTs/epoxy composites was 0.62 and 1.09 Wm−1 K−1 respectively. The formation of ZnO nanoparticles on MWCNTs was thus led to a decreasing of about 43% in thermal conductivity of the composite. However, the thermal conduction of the ZnO/MWCNTs/epoxy composite is significantly improved about 210% compared to that of neat epoxy. These results proposed a useful method to modify the surface of MWCNTs for the fabrication of epoxy nanocomposite where electrical-insulating and thermal conducting are both required. The composite was applied as an insulating edge coating for capacitive deionization electrodes

    Защита стальных поверхностей покрытиями на основе полиуретана и кремнийорганических соединений

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    Coatings of oligomethylsiloxane resin (OMES) and hydrolyzed heptadecafluorotetrahydrodecyltrimethoxysi-lane (HFS) oligomers were obtained by the spin-coating method on polyurethane (PU) - modified steel substrates. Their wettability and tribological properties were studied. It was found that the modification of the PU layer with silicon organic compounds increases its hydrophobicity and wear resistance. The water contact angles are 63.1° for a PU coating, 81.2° for PU/OMES and 115.8° for PU/HFS.Методом центрифугирования на стальных подложках, модифицированных полиуретаном (ПУ) сформированы покрытия олигометилсилоксановой смолы (ОМЕС) и олигомеров гидролизованного гептадекафтор-тетрагидродецилтриметоксисилана (ГФС), изучена их смачиваемость и трибологические свойства. Установлено, что модификация слоя ПУ кремнийорганическими соединениями увеличивает его гидрофобность и износоустойчивость. Краевые углы смачивания водой составляют для покрытий из ПУ - 63,1°, ПУ/ОМЕС - 81,2° и ПУ/ГФС - 115,8°
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