Optimization of variable blank holder force based on a sharing niching RBF neural network and an improved NSGA-II algorithm

Yan-Min Xie,Wei Tang,Fei Zhang,Bei-Bei Pan,Yaopeng Yue,Meiqiang Feng 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.2

Variable blank holder force (VBHF) is an important process parameter in sheet metal forming. The purpose of this study is to propose a sharing niching radial basis function (SNRBF) neural network for VBHF optimization. Two methods are put forward to improve the prediction accuracy of a RBF neural network. (1) A RBF neural network is trained by a sharing niching technique to achieve global optimal nodes. (2) In Latin hypercube design, Spearman correlation analysis is employed to decrease sample correlation. In addition, in order to improve the performance of the non-dominated sorting genetic algorithm (NSGA-II), excellent individuals in each class of non-dominated individuals are selected by employing immune operators. Based on the Spearman correlation analysis and the Latin hypercube method, training samples are generated and numerical simulations are performed for a double C part. The surrogate models between VBHF and forming quality are constructed by a SNRBF neural network. The Pareto frontier solutions are achieved by employing the improved NSGA-II algorithm. Grey relational analysis is applied to determine the optimal VBHF loading trajectory. The results show decreased wrinkles in the optimized forming part and greater uniformity in the plastic deformation by employing the optimized VBHF, thereby leading to improvement in the forming quality of the double C.

Study on NO enhanced absorption using FeIIEDTA in (NH4)2SO3 solution

Bei Yan,Jiehong Yang,Meng Guo,Gongda Chen,Zhao Li,Shuangchen Ma 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

In order to improve the performance of NO reductive removal using (NH4)2SO3 solution, a mixed solution of FeIIEDTA and (NH4)2SO3 was chosen as absorbing liquid for strengthening NO absorption in the bubbling reaction tower. The mechanism of NO removal using the mixture solution was analyzed, and the species transformation of FeIIEDTA was explored. The effects of pH, reaction temperature, FeIIEDTA concentration, concentrations of NO and SO2 on NO removal efficiency were investigated. The NO removal efficiency can exceed 80% under the optimum experimental conditions.

Experimental study on FeIICit enhanced absorption of NO in (NH4)2SO3 solution

Bei Yan,Jiehong Yang,Meng Guo,Sijie Zhu,Weijing Yu,Shuangchen Ma 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

FeIICit and (NH4)2SO3 mixed solution was selected as denitrification absorbent, and enhanced absorptionof NO was studied in a bubbling reaction column. The results show that, the highest NO removalefficiency achieved under the molar ratio of FeII to Cit was 1:2, NO removal efficiency decreased slightlywith the increase of pH in the range of experimental pH, the NO removal efficiency reduced with theincrease of temperature. NO removal efficiency increased slightly with the increasing concentrations ofimport NO, but decreased with the increasing gas flow rate. Validated experiment was carried out underthe optimum conditions in the double columns, the NO removal efficiency reached up to 71.66% within1 min and 48.14% within 6 min.

An Experimental and Numerical Investigation on the Twist Springback of Transformation Induced Plasticity 780 Steel Based on Different Hardening Models

Yan-Min Xie,Ren-Yong Huang,Wei Tang,Bei-Bei Pan,Fei Zhang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.4

Investigation on twist springback is important to improve the accuracy of forming parts. In this paper, a double C rail made of transformation induced plasticity 780 (TRIP 780) steel is designed, and the stamping and twist springback are simulated with ABAQUS based on three different hardening models (including Ziegler, Johnson-Cook and combined hardening models). A new index for calculating the twist springback is proposed, which is based on the angle between two end section lines of the double C rail. The experimental results of twist springback are compared with the calculation results from three different hardening models. The calculation results based on combined hardening model are the closest to the experiment data. In order to compensate twist springback, a curved surface die is designed based on the geometric shape of the double C rail after twist springback. The stamping and twist springback are simulated based on the curved surface die and combined hardening model, and the twist springback is decreased obviously after compensation, which shows that the compensation of twist springback is effective.

Development of Origanum vulgare Cell Suspension Culture to Produce Polyphenols and the Stimulation Effect of Salicylic Acid Elicitation and Phenylalanine Feeding

Yan-Ping Li,Dao-Bang Tang,Xiao-Qiang Wang,Meng Wang,Qing-Feng Zhang,Yuan Liu,Bei-Yun Shen,Jiguang Chen,Zhongping Yin 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.3

Three types of calli were induced from Origanum vulgare (O. vulgare) aseptic seedlings, and the friable calli with white appearance and high growth rate were further screened and used to develop cell suspension culture to produce polyphenols. Murashige and Skoog (MS) medium with 3.0 mg/L Kinetin (KT) and 0.5 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) was suitable for both O. vulgare cells growth and polyphenols accumulation. To further enhance the polyphenols accumulation, O. vulgare cells were treated by phenylalanine (Phe) feeding and salicylic acid (SA) elicitation. Compared with the individual Phe feeding and SA elicitation, SA elicitation combined with Phe feeding showed a much better promotion effect on the polyphenols synthesis in O. vulgare cells, especially rosmarinic acid (RosA) accumulation. With the combined treatment of 200 μM SA and 100 μM Phe, total polyphenols content and yield were 41.36 mg/g and 752.93 mg/L, respectively. RosA content and yield reached 31.25 mg/g and 570.37 mg/L, which were 5.44 and 5.47 times that of the control. Furthermore, the total polyphenols extracted from the cultured cells treated by SA elicitation combined with Phe feeding displayed a much higher antioxidant capacity than that of untreated cells, meanwhile its 1,1-diphenyl-2- trinitrophenyl hydrazine (DPPH) and superoxide anion radical-scavenging activity were much stronger than that of vitamin C. What’s more, our results also showed that RosA was the principal contributor to the fine antioxidant capacity of the total polyphenols extracted from the SA and Phe treated cells. Our research indicated that SA elicitation combined with Phe feeding significantly improved the polyphenols yield and antioxidant capacity of the cultured O. vulgare cells, and therefore has a promising application prospect in natural polyphenols production.

Fault detection based on polygon area statistics of transformation matrix identified from combined moving window data

Bei Wang,Xuefeng Yan,Yongfei Jin 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.2

Principal component analysis (PCA) has been widely used in monitoring industrial processes, but it is still necessary to make improvements in having a timely and effective access to variation information. It is known that the transformation matrix generated from real-time PCA model indicates inner relations between original variables and new produced components, so this matrix would be different when modeling data deviate due to the change of the operating condition. Based on this theory, this paper proposes a novel real-time monitoring approach which utilizes polygon area method to measure the variation degree of the transformation matrices and then constructs a statistic for monitoring purpose. The on-line data are collected through a combined moving window (CMW), containing both normal and monitored data. To evaluate the performance of the proposed method, a simple numerical simulation, the CSTR process and the classic Tennessee Eastman process are employed for illustration, with some PCA-based methods used for comparison.

Signal Processing and Development Process Based on “MOOC + SPOC + Flipped Classroom”

( Bei Qiao ),( Yan Mi ) 한국정보처리학회 2024 Journal of information processing systems Vol.20 No.1

The hybrid teaching approach of “MOOC + SPOC + Flipped Classroom” overcomes the constraints of time and space that are typically associated with traditional teaching methods, thus compensating for the shortcomings of traditional approaches. These changes in education are driven by the “Internet+” wave and the growing popularity of online teaching. The “MOOC + SPOC + Flipped Classroom” hybrid teaching mode can successfully compensate for the drawbacks of traditional teaching methods, thereby overcoming their restrictions. By defining relevant concepts, one can distill the key characteristics of the “MOOC + SPOC + Flipped Classroom” hybrid teaching mode. Formative assessment was employed to thoroughly evaluate the effectiveness of this teaching approach. By leveraging the advantages of massive open online course (MOOC), small private online course (SPOC), and flipped classroom, the “MOOC +SPOC + Flipped Classroom” teaching mode incorporates real-time student assessment through peer evaluation, computer-aided evaluation, and teacher evaluation. This mode promotes the simultaneous development of theoretical knowledge and practical skills, helping students to establish strong foundations while fostering their practical abilities. While the traditional teaching method remains fruitful, the convenience of today's network allows the teaching profession to continually evolve. The traditional teaching mode heavily relies on teachers, making it impossible to conduct lessons without them. However, the development of MOOC enables students to seek knowledge online from their preferred teachers, rather than solely relying on their assigned instructors.

Fault detection and identification using a Kullback-Leibler divergence based multi-block principal component analysis and bayesian inference

Bei Wang,Xuefeng Yan,Qingchao Jiang 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.6

Considering the huge number of variables in plant-wide process monitoring and complex relationships(linear, nonlinear, partial correlation, or independence) among these variables, multivariate statistical process monitoring(MSPM) performance may be deteriorated especially by the independent variables. Meanwhile, whether related variableskeep high concordance during the variation process is still a question. Under this circumstance, a multi-block technologybased on mathematical statistics method, Kullback-Leibler Divergence, is proposed to put the variables having similarstatistical characteristics into the same block, and then build principal component analysis (PCA) models in each lowdimensionalsubspace. Bayesian inference is also employed to combine the monitoring results from each sub-blockinto the final monitoring statistics. Additionally, a novel fault diagnosis approach is developed for fault identification. The superiority of the proposed method is demonstrated by applications on a simple simulated multivariate processand the Tennessee Eastman benchmark process.

Combined Effects of Six Cytokine Gene Polymorphisms and SNP-SNP Interactions on Hepatocellular Carcinoma Risk in Southern Guangxi, China

Bei, Chun-Hua,Bai, Hua,Yu, Hong-Ping,Yang, Yan,Liang, Qing-Qing,Deng, Ying-Ying,Tan, Sheng-Kui,Qiu, Xiao-Qiang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Cytokine gene single nucleotide polymorphisms (SNPs) are involved in the genesis and progression of hepatocellular carcinoma (HCC). We hypothesized that combined effects of cytokine gene SNPs and SNP-SNP interactions are associated with HCC risk. Six SNPs in cytokine genes (IL-2, IFN-${\gamma}$, IL-$1{\beta}$, IL-6, and IL-10) were genotyped in a study of 720 Chinese HCC cases and 784 cancer-free controls. Although none of these SNPs individually had a significant effect on the risk of HCC, we found that the combined effects of these six SNPs may contribute to HCC risk (OR=1.821, 95% CI=1.078-3.075). This risk was pronounced among smokers, drinkers, and hepatitis B virus carriers. A SNP-SNP interaction between IL-2-330 and IFN-${\gamma}$-1615 was associated with an increased HCC risk (OR=1.078, 95% CI=1.022-1.136). In conclusion, combined effects of SNPs and SNP-SNP interactions in cytokine genes may contribute to HCC risk.

Monitoring the Ecology of Bacillus During Daqu Incubation, a Fermentation Starter, Using Culture-Dependent and Culture-Independent Methods

( Yan Zheng ),( Xiao Wei Zheng ),( Bei Zhong Han ),( Jian Shu Han ),( M J Robert Nout ),( Jing Yu Chen ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.5

Daqu, a traditional fermentation starter, has been used to produce attractively flavored foods such as vinegar and Chinese liquor for thousands of years. Although Bacillus spp. are one of the dominant microorganisms in Daqu, more precise information is needed to reveal why and how Bacillus became dominant in Daqu, and next, to assess the impact of Bacillus sp. on Daqu and its derived products. We combined culture-dependent and culture-independent methods to study the ecology of Bacillus during Daqu incubation. Throughout the incubation, 67 presumptive Bacillus spp. isolates were obtained, 52 of which were confirmed by 16S rDNA sequencing. The identified organisms belonged to 8 Bacillus species: B. licheniformis, B. subtilis, B. amyloliquefaciens, B. cereus, B. circulans, B. megaterium, B. pumilus, and B. anthracis. A primer set specific for Bacillus and related genera was used in a selective PCR study, followed by a nested DGGE PCR targeting the V9 region of the 16S rDNA. Species identified from the PCR-DGGE fingerprints were related to B. licheniformis, B. subtilis, B. amyloliquefaciens, B. pumilus, B. benzoevorans, and B. foraminis. The predominant species was found to be B. licheniformis. Certain B. licheniformis strains exhibited potent antimicrobial activities. The greatest species diversity occurred at the Liangmei stage of Daqu incubation. To date, we lack sufficient knowledge of Bacillus distribution in Daqu. Elucidating the ecology of Bacillus during Daqu incubation would enable the impact of Bacillus on Daqu to be accessed, and the quality and stabilization of Daqu-derived products to be optimized.