Srinakharinwirot Science Journal Srinakharinwirot Science Journal Faculty of Science en-US Srinakharinwirot Science Journal 0857-1600 Buddhist Amulet Recognition by Using ResNet50 <p>The objective of this research is to develop a computer system which can recognize Buddhist amulet images. The system is called “Buddhist amulet recognition system (BARS)”. BARS consists of four main modules, namely: 1) dataset training, 2) image acquisition, 3) ResNet50 classification and 4) result presentation. The system dataset consists of 3,248 images belonging to 203 amulet types, with 16 images per type. The system analyzed both metal &amp; clay amulets, which consisted of 146 metal amulets and 57 clay ones. BARS employed the pre-training convolutional neural network (CNN) called “ResNet50” in MATLAB for recognizing Buddhist amulets. The accuracy, sensitivity, specificity and precision rates for the training dataset of BARS are 0.9998, 0.9879, 0.9999 and 0.9879, respectively. The system also conducted cross-validation on an untrained dataset, which has accuracy, sensitivity, specificity and precision rates of 0.9999, 0.9541, 0.9999 and 0.9541, respectively. The average training time is 3,183.2 seconds and the average access time is 1.34 second per image. Finally, this research compares the accuracy of ResNet18, ResNet50 and ResNet101, with the same amulet dataset.</p> Chomtip - Pornpanomchai Varin Pornpanomchai Copyright (c) 2022 Srinakharinwirot Science Journal 2022-12-30 2022-12-30 38 2 1 14 Clustering Performance Comparison in K-Mean Clustering Variations: A Fraud Detection Study <p>K-means clustering is a common clustering approach that is based on data partitioning. However, the k-means clustering has significant drawbacks, such as it is sensitive to deciding the initial condition. Several ways to improve the algorithm have been offered. To assess the algorithm's efficiency and correctness, the performance comparison should be evaluated. In this paper, several k-means algorithms, including random k-means, global k-means, and fast global k-means, were evaluated for their efficiency when applied to a fraud detection data set. The accuracy of each method and the Davies-Bouldin index was investigated for each algorithm to compare the clustering performance. The findings demonstrated that when a small number of groups was used, random k-means, global k-means, and fast global k-means gave similar clustering, but fast global k-means offered better errors when a big number of groups was used. Furthermore, global k-means took longer to execute than others.</p> Subhorn Khonthapagdee Nattaporn Chuenjarern Copyright (c) 2022 Srinakharinwirot Science Journal 2022-12-30 2022-12-30 38 2 15 25 Biflavonoids from Root Barks of Garcinia cowa with Radical Scavenging Activity <p>Plants of the Clusiaceae family have received considerable attention due to their availability of interesting secondary metabolites. We have previously collected a number of phytochemicals from the <em>Garcinia</em> species. In continuation of the search for new bioactive substances from Thai natural resources, we have found that the MeOH extract obtained from the root barks of <em>Garcinia cowa</em> Roxb., exhibited a significant antioxidative activity. Subsequently isolation, four compounds of the 3,8" linked biflavonoids were yielded and identified as (+) volkensiflavone (<strong>1</strong>), (+) morelloflavone (<strong>2</strong>), (+) spicataside (<strong>3</strong>), and (+) fukugiside (<strong>4</strong>). Their chemical structures were mainly elucidated by NMR data analysis and by comparison with the reported values. The antioxidant capacity of the isolates was tested using DPPH scavenging assay and compounds <strong>2 </strong>and<strong> 4 </strong>exhibited strong activity with IC<sub>50</sub> values of 8.85 and 19.65 μg/mL, respectively. The highest activity of compound <strong>2</strong> which was comparable to that of the positive control, revealed the importance of both phenolic hydroxyls at C-3 and C-4 on ring E of the biflavonoid framework.</p> Sunit Suksamran Pongsan Kornanan Audchara Saenkham Jannarin Nontakham Prayumat Onsrisawat Kulvadee Dolsophon Prasert Pattanaprateeb Copyright (c) 2022 Srinakharinwirot Science Journal 2022-12-30 2022-12-30 38 2 26 36 A DFT-based Analysis of Metals Adsorption on Chitosan Monomer <p>The generation of waste electrical and electronic equipment (WEEE or E-waste) has been noted as an increasing category of waste. In this work, the density functional theory (DFT) was used to investigate the adsorption process between chitosan (CS) and metals at the B3LYP level with 6-31G(d,p) and LANL2DZ basis sets. The effect of solvent was included using the polarizable continuum model (PCM) consisting of water. Ag<sup>+</sup>, As<sup>3+</sup>, Ba<sup>2+</sup>, Be<sup>2+</sup>, Cd<sup>2+</sup>, Co<sup>2+</sup>, Cr<sup>3+</sup>, Cu<sup>2+</sup>, Hg<sup>2+</sup>, Li<sup>+</sup>, Mn<sup>2+</sup>, Ni<sup>2+</sup>, Pb<sup>2+</sup>, Pd<sup>2+</sup>, Sb<sup>3+</sup>, Sn<sup>2+</sup>, Sr<sup>2+</sup>, Tl<sup>+</sup>, and Zn<sup>2+ </sup>have been selected to be studied because of high impact in E-waste. Different analyses were carried out: adsorption energy, HOMO-LUMO energy gaps, hardness, softness, frontier molecular orbitals, and molecular electrostatic potential (MEP), and all of which are necessary to predict the formation of complexes. The interaction between CS and metal species was shown in almost all cases as covalent partial. In addition, all metals were placed closeer to the nitrogen atom than the oxygen atom of CS because the charge density of the nitrogen is increased in the formation of the Schiff base. Finally, the monomer derived from CS has good stability in water and is, therefore, considered as a good material in the field of environmental pollution.</p> Malinee Promkatkaew Sunan Kitjaruwankul Supaporn Baiya Suree Tongwanichniyom Pornthip Boonsri Supa Hannongbua Copyright (c) 2022 Srinakharinwirot Science Journal 2022-12-30 2022-12-30 38 2 37 47 Molecular Design of the Triphenylamine Substitution on Isoindigo-Based as Promising Hole Transport Materials for Perovskite Solar Cell <p>The performance of perovskite solar cells (PSCs) controlling the hole mobility is the fundamental importance. The development of novel hole transport materials (HTMs) with good stability, low cost and high hole mobility for PSCs has attracted much attention for researchers. In this work, new isoindigo-based HTMs substituted with two triphenylamine (TPA) with the donor-acceptor-donor (D-A-D) architecture, were designed computationally. The effect of π-extension influence on the charge transfer process was investigated by insertingof two vinyl groups between acceptor and donor parts (D-π-A-π-D). The correlation between electronic structure and hole transport properties of the designed HTMs was determined by tuning the connection between donor and acceptor. The ground state of the HTMs was fully optimized by DFT method at B3LYP/6-31G(d,p), and the excited state, absorption and emission properties of the HTMs were carried out by using the TD-DFT at cam-B3LYP/6-31G(d,p) in dichloromethane solvent based on the conductor-like polarizable continuum model (C-PCM). The calculated HOMO, LUMO and band gap values of the HTMs showed higher values than that of MAPbI<sub>3</sub> (perovskite). Hence, the charge distribution in HOMO and LUMO of our designed structures could qualitatively predicted the carrier injection and transportation in the PSCs. The adsorption spectra were broader, indicating that the proposed HTMs absorbed a large amount of visible light, which might impact the electron delocalization. This designed HTMs would have the potential for synthesis of new HTMs.</p> Nachaphon Ngueanngam Tanchanok Chaivisuthangkura Nahathai Asawutmangkul Benchawan Jityuti Pornthip Boonsri Copyright (c) 2022 Srinakharinwirot Science Journal 2022-12-30 2022-12-30 38 2 48 61 Preparation of ZnO-SrO-B2O3 Glass Systems Doped with Dy2O3 for the White Light Emission Material Application <p>ZnO-SrO-B<sub>2</sub>O<sub>3 </sub>glasses doped with Dy<sup>3+ </sup>ions were prepared by a conventional melt quenching technique. The molar volume density and refractive index tends to increase with increasing of Dy<sub>2</sub>O<sub>3 </sub>concentration. The absorption bands show energy levels transition from <sup>6</sup>H<sub>15/2</sub> ground state to excited states such as 781 nm (<sup>6</sup>F<sub>3/2</sub>), 801 nm (<sup>6</sup>F<sub>5/2</sub>), 895 nm (<sup>6</sup>F<sub>7/2</sub>), 1083 nm (<sup>6</sup>F<sub>9/2</sub>), 1254 nm (<sup>6</sup>F<sub>11/2</sub>) and 1661 nm (<sup>6</sup>H<sub>11/2</sub>), and the intensity of the peak at 1254 nm is the highest. The excitation spectra of the 7 peaks glass sample were found in the wavelength range of 320-470 nm with the highest intensity peak at 386 nm. The emission spectra represent four emission bands, and all emission bands are over the visible range. The peak at 575 nm is the highest intensity peak. The CIE chromaticity (x,y) coordinates fall in the white light region of the CIE chromaticity diagram. The experimental decay time (τ<sub>exp</sub>) of <sup>6</sup>H<sub>13/2 </sub>transition of Dy<sup>3+</sup> ions obtained from the measurement tends to increase with increasing of Dy<sub>2</sub>O<sub>3 </sub>concentration. These results show the potential for use in white LED applications.</p> Rungsan Ruamnikhom Inamullah Khan Patarawagee Yasaka Jakrapong Kaewkhao Copyright (c) 2022 Srinakharinwirot Science Journal 2022-12-30 2022-12-30 38 2 62 71 Switching-Concentration Effect of Li2O and Al2O3 on Phosphate Glass Doped with Nd2O3 <p>The purpose of this study was to determine the switching-concentration effect of Li<sub>2</sub>O and Al<sub>2</sub>O<sub>3</sub> on phosphate glass doped with neodymium ions. The 64P<sub>2</sub>O<sub>5</sub>-20Li<sub>2</sub>O-15Al<sub>2</sub>O<sub>3</sub>-1Nd<sub>2</sub>O<sub>3</sub> glass was measured and analyzed for density, refractive index, absorption and near-infrared emission spectrum. The density and refractive index showed values of 2.5695 g/cm<sup>3 </sup>and 1.5236, respectively. The optical absorption was measured and showed twelve bands in the range of 300–1500 nm. It was observed that the most intense transition <sup>4</sup>I<sub>9/2</sub>→<sup>4</sup>G<sub>5/2</sub> was centered at around 581 nm, which was chosen to investigate the near-infrared emission spectrum. The intense band of emission spectrum with <sup>4</sup>F<sub>3/2</sub>→<sup>4</sup>I<sub>11/2 </sub>transition was shown in wavenumber at 9442.87 cm<sup>-1</sup> (1059 nm). The Judd-Ofelt and radiative parameters were calculated and collected to support the possibility of laser application.</p> chayani setiades sarumaha juniastel rajagukguk Natthakridta Chanthima Jakrapong Kaewkhao Copyright (c) 2022 Srinakharinwirot Science Journal 2022-12-30 2022-12-30 38 2 72 80