Farhad Mortezapour Shiri^1,*, Ehsan Ahmadi², Mohammadreza Rezaee¹, Thinagaran Perumal¹

Journal on Artificial Intelligence, Vol.6, pp. 85-103, 2024, DOI:10.32604/jai.2024.048911

Abstract Automatic detection of student engagement levels from videos, which is a spatio-temporal classification problem is crucial for enhancing the quality of online education. This paper addresses this challenge by proposing four novel hybrid end-to-end deep learning models designed for the automatic detection of student engagement levels in e-learning videos. The evaluation of these models utilizes the DAiSEE dataset, a public repository capturing student affective states in e-learning scenarios. The initial model integrates EfficientNetV2-L with Gated Recurrent Unit (GRU) and attains an accuracy of 61.45%. Subsequently, the second model combines EfficientNetV2-L with bidirectional GRU (Bi-GRU), yielding an accuracy of 61.56%. The… More >

Qing Zhu^1,*, Linlin Gu^1,2, Huijie Lin^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 577-591, 2024, DOI:10.32604/cmes.2023.043307

Abstract With the rapid development of electric power systems, load estimation plays an important role in system operation and planning. Usually, load estimation techniques contain traditional, time series, regression analysis-based, and machine learning-based estimation. Since the machine learning-based method can lead to better performance, in this paper, a deep learning-based load estimation algorithm using image fingerprint and attention mechanism is proposed. First, an image fingerprint construction is proposed for training data. After the data preprocessing, the training data matrix is constructed by the cyclic shift and cubic spline interpolation. Then, the linear mapping and the gray-color transformation method are proposed to… More >

JIA SHAO^1,2, CAN ZHANG², YAONAN TANG², AIQIN HE², WEIPEI ZHU^1,*

BIOCELL, Vol.48, No.4, pp. 571-580, 2024, DOI:10.32604/biocell.2024.049092

Abstract Objective: Previous studies indicated that aberrant circular RNA (circRNA) expression affects gene expression regulatory networks, leading to the aberrant activation of tumor pathways and promoting tumor cell growth. However, the expression, clinical significance, and effects on cell propagation, invasion, and dissemination of circRNA_001896 in cervical cancer (CC) tissues remain unclear. Methods: The Gene Expression Omnibus (GEO) datasets (GSE113696 and GSE102686) were used to examine differential circRNA expression in CC and adjacent tissues. The expression of circRNA_001896 was detected in 72 CC patients using fluorescence quantitative PCR. Correlation analysis with clinical pathological features was performed through COX multivariate and univariate analysis.… More >

YARA ALZGHOUL, HALA J. BANI ISSA, AHMAD K. SANAJLEH, TAQWA ALABDUH, FATIMAH RABABAH, MAHA AL-SHDAIFAT, EJLAL ABU-EL-RUB^*, FATIMAH ALMAHASNEH, RAMADA R. KHASAWNEH, AYMAN ALZU’BI, HUTHAIFA MAGABLEH

BIOCELL, Vol.48, No.4, pp. 559-569, 2024, DOI:10.32604/biocell.2024.048056

Abstract Mesenchymal stem cells (MSCs) are ideal candidates for treating many cardiovascular diseases. MSCs can modify the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities, which are essential to restore heart function. MSCs can be easily isolated from different sources, including bone marrow, adipose tissues, umbilical cord, and dental pulp. MSCs from various sources differ in their regenerative and therapeutic abilities for cardiovascular disorders. In this review, we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function. More >

Moumouni Sidibé^1,2,*, Augustin K. N. Aoudji¹, Yaya Issifou Moumouni^3,*, Issa Sacko⁴, Idelphonse Saliou¹, Bourema Koné², Achille Ephrem Assogbadjo⁵, Afio Zannou¹

Revue Internationale de Géomatique, Vol.33, pp. 51-76, 2024, DOI:10.32604/rig.2024.045505

Abstract Land use dynamics is a prerequisite for identifying natural resource management constraints, the evolution of agrarian practices and population growth. The objective of this research is to improve knowledge of the dynamics of agricultural land use in the dryland (Cinzana) and cotton (Kléla) areas of Mali. The methodology used consisted of planimetric data collection and diachronic analysis using Landsat TM (Thematic Mapper) satellite images from 2000 and OLI (Operational Land Image) from 2020. Degradation and deforestation rates of natural formations were calculated on the one hand, and on the other hand, the speed and intensity of changes were evaluated using… More > Graphic Abstract

SACHIN SINGH^a, MUKTI TYAGI^a,*, AJAY KUMAR TYAGI^a, PRAVEEN KUMAR KAICKER^a, LALIT VARSHNEY^b

Journal of Polymer Materials, Vol.36, No.4, pp. 305-321, 2019, DOI:10.32381/JPM.2019.36.04.2

Abstract Graphite is the most suitable material as dry lubricant. However, its application as a lubricant is limited with necessity of moisture vapors. Alternatively, polytetrafluoroethylene (PTFE) has an excellent lubrication property but does not have mechanical characteristics. The effect of gamma radiation doses on the lubrication behavior of graphite –PTFE (Inoflon A-408) system has been studied using (TR-TW-30L) tribotester with thrust washer attachment. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Improved tribological properties of graphite –PTFE system showed by decrease in coefficient of friction and wear. SEM-EDX, XRD and contact angle analysis confirm fluorination of… More >

KEMIN WANG, LIFEI HE

Journal of Polymer Materials, Vol.36, No.3, pp. 253-260, 2019, DOI:10.32381/JPM.2019.36.03.5

Abstract This study proposes a simple approach for the fabrication of microspherical catalysts with a hierarchical porous structure. The cross-linked porous microspheres with catalytic ability were prepared directly from small-molecular monomers via low-temperature phase-separation photopolymerization of water/oil suspension. The morphology, pore size, chemical structure, and thermal stability of the obtained porous microspheres were characterized by SEM, Mercury Intrusion Porosimetry, FTIR, and TGA. The porous microspheres directly served as an acid catalyst for the condensation reaction of benzaldehyde and ethylene glycol, which exhibited superior catalytic activity and recyclability. The results indicated that such porous microspheres have great potential in the application of… More >

YAN WANG^A, LI-FANG ZHANG^A,B,C,*, XIAO-QI WANG^B

Journal of Polymer Materials, Vol.37, No.1-2, pp. 77-89, 2020, DOI:10.32381/JPM.2020.37.1-2.6

Abstract The effect of 18-crown-6 ether (18C6) on the anionic polymerization of ε-caprolactone (ε -CL) using potassium tert-butoxide (t-BuOK) as the initiator was studied. The experimental results showed that 18C6 in combination with t-BuOK exhibited high selectivity for ring opening relative to trans-esterification and improved control toward the ROP of ε-CL, producing poly(ε- caprolactone) (PCL) with much higher molecular weight and relatively narrow distribution compared to those using t-BuOK alone as the initiator.The influences of reaction conditions, such as monomer concentration, monomer/initiator molar ratio, and [18C6]/[t-BuOK] molar ratio, as well as reaction temperature and time on the polymerization have been examined… More >

ZHAO JUN^a, LIU AIQIN^a, ZHOU HONG^a, LUO JUN^b,*, AND LIU YUAN^b,*

Journal of Polymer Materials, Vol.37, No.1-2, pp. 29-42, 2020, DOI:10.32381/JPM.2020.37.1-2.3

Abstract Heteroatoms (N, O, and F) and hydrogen groups are important elements for forming the H-bonds. It is well known that a large number of hydrogen groups are formed after curing reaction of epoxy. However, literatures about epoxy resins containing heteroaromatic ring and the H-bonds after cure reaction of the epoxy resins are seldom published. To bridge the gap, a kind of new epoxy monomer containing pyridine ring (EMP) has been synthesized in this work, andit is further cured by 4,4-diaminodiphenyl methane (DDM). The properties of cured EMP/ DDM are evaluated by DSC, DMA, and static contact angle measurement. Moreover, the… More >

BAOHAI PAN^1,2, JUNCHENG HUANG¹, LAI CHEN², FEI LIU^1,*, CHEN JING, HAINING NA^1,*, JIN ZHU¹

Journal of Polymer Materials, Vol.37, No.1-2, pp. 17-27, 2020, DOI:10.32381/JPM.2020.37.1-2.2

Abstract A switchable CO₂ /1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)/dimethyl sulfoxide (DMSO) solvent system is applied to prepare corn cellulose film with controllable mechanical property. By use of the switchable CO₂ /DBU/DMSO system, a rather simple process concerning reacted dissolution and heated precipitation controlled by addition and releasing of CO₂ respectively, to prepare corn cellulose film, is formed. Results exhibit the degree of dissolution of corn cellulose is easily controlled just by adjusting the feeding amount of DBU in the switchable solvent system. Accordingly, some undissolved part of corn cellulose with relative high crystallinity can be appropriately retained to contribute to the improvement of mechanical… More >