Adaptive Multi-class Segmentation Model of Aggregate Image Based on Improved Sparrow Search Algorithm

Mengfei Wang,Weixing Wang,Sheng Feng,Limin Li 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.2

Aggregates play the skeleton and supporting role in the construction field, high-precision measurement and high-efficiency analysis of aggregates are frequently employed to evaluate the project quality. Aiming at the unbalanced operation time and segmentation accuracy for multi-class segmentation algorithms of aggregate images, a Chaotic Sparrow Search Algorithm (CSSA) is put forward to optimize it. In this algorithm, the chaotic map is combined with the sinusoidal dynamic weight and the elite mutation strategies; and it is firstly proposed to promote the SSA’s optimization accuracy and stability without reducing the SSA’s speed. The CSSA is utilized to optimize the popular multi-class segmentation algorithm-Multiple Entropy Thresholding (MET). By taking three METs as objective functions, i.e., Kapur Entropy, Minimum-cross Entropy and Renyi Entropy, the CSSA is implemented to quickly and automatically calculate the extreme value of the function and get the corresponding correct thresholds. The image adaptive multi-class segmentation model is called CSSA-MET. In order to comprehensively evaluate it, a new parameter I based on the segmentation accuracy and processing speed is constructed. The results reveal that the CSSA outperforms the other seven methods of optimization performance, as well as the quality evaluation of aggregate images segmented by the CSSA-MET, and the speed and accuracy are balanced. In particular, the highest I value can be obtained when the CSSA is applied to optimize the Renyi Entropy, which indicates that this combination is more suitable for segmenting the aggregate images.

Fluorination of dichlorodifluoromethane to synthesize tetrafluoromethane over Cr_2O_3–AlF_3 catalyst

Wenzhi Jia,Mengfei Luo,Lingyun Jin,Yuejuan Wang,Jiqing Lu 한국공업화학회 2011 Journal of Industrial and Engineering Chemistry Vol.17 No.3

A series of Cr_2O_3–AlF_3 catalysts with different Cr_2O_3 contents were prepared by a deposition–precipitation method for the fluorination of dichlorodifluoromethane (CCl_2F_2) to synthesize tetrafluoromethane (CF4). The highest activity was obtained on the Cr_2O_3–AlF_3 catalyst containing 61.2 wt.% of Cr_2O_3, with the CF_4 yield of 94% at 400℃. X-ray diffraction (XRD) and Raman spectroscopy results indicated the presence of bulk Cr_2O_3 and a-AlF_3 phases in the catalysts. Ammonia temperature programmed desorption (NH3-TPD) and Fourier transformation infrared spectroscopy (FTIR) of pyridine chemisorption revealed strong Lewis acidity of the catalysts. The Cr species and Lewis acid in the Cr_2O_3–AlF_3 catalysts were the active sites of fluorination and dismutation reaction of CCl_2F_2, respectively. This indicated bi-function catalytic performance of Cr_2O_3–AlF_3 catalysts for fluorination and dismutation reaction.

ICT1 deficiency leads to reduced oxygen resistance due to the cell wall damage in S. cerevisiae

Zhu Hong,Wang Mengfei,Zhou Hua,Cai Heng 한국유전학회 2022 Genes & Genomics Vol.44 No.8

Background: Disruption of ICT1 has been known to cause a significant deficiency in the phospholipid composition which is necessary for cell stress adaptation. However, the effects of ICT1 deletion on antioxidant research are not clear. Objective: Construct a knockout strain to investigate the efficacy of ICT1 on antioxidant activity. Methods: The antioxidant-related genes and phospholipid-related genes were determined by RT-PCR, the cell wall shape was observed by TME, and CWI pathway phosphorylation experiments were also analyzed by HPLC. Results: The expression of antioxidant related genes and phospholipid-related genes has a slight reduction compared to the wild type. The cell wall was observed impaired with apparent CWI pathway phosphorylation weakening in the mutant. Conclusion: These findings indicate the role of ICT1 on antioxidant activity because it not only directly affects phospholipid composition but also further leads to the activation of CWI.

Observing the Characteristics of Multi-Activity Trip Chain and Its Influencing Mechanism

Linbo Li,Mengfei Cao,Jiajun Yin,Yanli Wang,Sabyasachee Mishra 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.11

Understanding mechanism of daily activity trip chain especially multi-activity trip chain is significant for travel demand management and urban redevelopment. This paper explores the multi-activity trip chain behavior from both individual attributes and spatial attributes. Multi- activity trip chain is identified from people’s full-day travel diaries, then categorized into multi-activity intermittent trip chain and continuous trip chain to distinguish the characteristics and influencing factors of different chains. Using resident travel survey data of Xiaoshan District of Hangzhou, China, multinomial logistic regression model, transition probability matrix and activity analysis methods are employed to make analyses. Findings include: 1) making multi-activity trip chain can achieve multiple purposes with less average travel time for each purpose, but public transit is less used. 2) The choices of single or multi-activity trip chain and multi-activity intermittent or continuous trip chain are mainly affected by different individual attributes such as occupation, education, household income, etc. Moreover, household registration, driver’s license, gender, and household car ownership are related to the choice of activity sequence. 3) For typical trip chain with purposes of work, shopping/dining, and home, activity sequence is also obviously influenced by spatial distance between origin and destination, especially for the chain of work-shopping/dining-home.

Improved biodegradation of polyvinyl alcohol by hybrid nanoflowers of degrading enzymes from Bacillus niacini

Hongjie Bian,Gaoyang Wang,Mengfei Cao,Ziyuan Wang,Jiandong Cui 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.6

Polyvinyl alcohol (PVA) is a synthetic polymer that is difficult to degrade in nature. In this study, we synthesized PVA-degrading enzymes (PVAase)-Cu3(PO4)2 hybrid nanoflowers by using crude PVAase from Bacillus niacini for PVA degradation. The influences of PVAase concentration, Cu2+ concentration, and incubation time on the nucleation and activity of the PVAase hybrid nanoflower were investigated. The maximal activity recovery of the PVAase hybrid nanoflower was approximately 85% at 0.25 mg/mL of PVAase, 0.36mM Cu2+, and 72 h incubation time. The optimum temperature and pH of PVAase did not change before and after immobilization. Compared with free PVAase, the PVAase hybrid nanoflower showed high thermal stability and storage stability. Additionally, the PVAase hybrid nanoflower displayed excellent reusability after eight cycles and promising PVA degradability, indicating its potential application in PVA degradation.

Complete Mitochondrial Genome of the Chagas Disease Vector, Triatoma rubrofasciata

Li Dong,Xiaoling Ma,Mengfei Wang,Dan Zhu,Yuebiao Feng,Yi Zhang,Jingwen Wang 대한기생충학열대의학회 2018 The Korean Journal of Parasitology Vol.56 No.5

Triatoma rubrofasciata is a wide-spread vector of Chagas disease in Americas. In this study, we completed the mitochondrial genome sequencing of T. rubrofasciata. The total length of T. rubrofasciata mitochondrial genome was 17,150 bp with the base composition of 40.4% A, 11.6% G, 29.4% T and 18.6% C. It included 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one control region. We constructed a phylogenetic tree on the 13 protein-coding genes of T. rubrofasciata and other 13 closely related species to show their phylogenic relationship. The determination of T. rubrofasciata mitogenome would play an important role in understanding the genetic diversity and evolution of triatomine bugs.

A new green alternative solvent for extracting echinacoside and acteoside from Cistanche deserticola based on ternary natural deep eutectic solvent

Fang Nie,Changyin Feng,Naveed Ahmad,Mengfei Tian,Qinglong Liu,Weihao Wang,Ziqi Lin,Chunying Li,Chunjian Zhao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

Echinacoside and acteoside, the representative constituents of Cistanche deserticola Y. C. Ma (C. deserticola),are known for its many important biological activities. In this study, a novel ternary natural deepeutectic solvent (NADES) (citric acid, fructose and glucose in a 1:2:1 molar ratio, 30 % water content)was obtained through the adjustment and optimization of single-factor experiments. And through theBox-Behnken design optimization, the optimal extraction conditions were obtained, at the moment,the yields of echinacoside and acteoside were 6.16 and 2.13 mg/g, respectively. In addition, through computermolecular simulation, it was found that there are strong hydrogen bonds and interactions betweenthe molecules of NADES, and the hydrogen bonds, van der Waals forces and p-p interactions played animportant role in the extraction of echinacoside and acteoside from C. deserticola by NADES. Finally, comparedwith the traditional method, NADES ultrasound-assisted extraction of echinacoside and acteosidehas a shorter time (15 min), the maximum extraction yield is 1.54–2.86 times and 1.26–2.52 times thanthat of traditional extraction methods for echinacoside and acteoside, respectively. This study demonstratesthat NADES can provides a new direction for developing new sustainable alternatives, improvinggreen extraction process and efficiency for extracting natural active substances.