A Dual-Population Memetic Algorithm for Minimizing Total Cost of Multi-Mode Resource-Constrained Project Scheduling

Zhi-Jie Chen,Chiuh-Cheng Chyu 대한산업공학회 2010 Industrial Engineeering & Management Systems Vol.9 No.2

Makespan and cost minimization are two important factors in project investment. This paper considers a multi-mode resource-constrained project scheduling problem with the objective of minimizing costs, subject to a deadline constraint. A number of studies have focused on minimizing makespan or resource availability cost with a specified deadline. This problem assumes a fixed cost for the availability of each renewable resource per period, and the project cost to be minimized is the sum of the variable cost associated with the execution mode of each activity. The presented memetic algorithm (MA) consists of three features: (1) a truncated branch and bound heuristic that serves as effective preprocessing in forming the initial population; (2) a strategy that maintains two populations, which respectively store deadline-feasible and infeasible solutions, enabling the MA to explore quality solutions in a broader resource-feasible space; (3) a repair-and-improvement local search scheme that refines each offspring and updates the two populations. The MA is tested via ProGen generated instances with problem sizes of 18, 20, and 30. The experimental results indicate that the MA performs exceptionally well in both effectiveness and efficiency using the optimal solutions or the current best solutions for the comparison standard.

A Dual-Population Memetic Algorithm for Minimizing Total Cost of Multi-Mode Resource-Constrained Project Scheduling

Chen, Zhi-Jie,Chyu, Chiuh-Cheng Korean Institute of Industrial Engineers 2010 Industrial Engineeering & Management Systems Vol.9 No.2

Makespan and cost minimization are two important factors in project investment. This paper considers a multi-mode resource-constrained project scheduling problem with the objective of minimizing costs, subject to a deadline constraint. A number of studies have focused on minimizing makespan or resource availability cost with a specified deadline. This problem assumes a fixed cost for the availability of each renewable resource per period, and the project cost to be minimized is the sum of the variable cost associated with the execution mode of each activity. The presented memetic algorithm (MA) consists of three features: (1) a truncated branch and bound heuristic that serves as effective preprocessing in forming the initial population; (2) a strategy that maintains two populations, which respectively store deadline-feasible and infeasible solutions, enabling the MA to explore quality solutions in a broader resource-feasible space; (3) a repair-and-improvement local search scheme that refines each offspring and updates the two populations. The MA is tested via ProGen generated instances with problem sizes of 18, 20, and 30. The experimental results indicate that the MA performs exceptionally well in both effectiveness and efficiency using the optimal solutions or the current best solutions for the comparison standard.

An Improved Method of Maximum Power Point Tracking Strategy for Wind Power Conversion System

CHEN Ran,CHEN Jie,CHEN Jia-wei,CHEN Zhi-hui,GONG Chun-ying,YAN Yang-guang 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

The turbine speed loop adjustment is the key link of the designing of the controller for the fixed pitch variable speed wind energy conversion systems (WECS). Because of the strong nonlinear, big inertia and mechanical damping characteristics, it’s difficult to designing the controller of the wind power systems. In this paper, a small signal model is present, and based on the analyzing; a wind turbine speed loop regulator is designed. Then, a method of tracking the peak power conversion system is proposed, which is independent of the turbine parameters and air density. At last, simulation system is built, and the results of the simulation experiments show that, the performance of the controller algorithm meet the requirements of the MPPT without wind measurement.

Post-fi re Behavior of Welded Hollow Spherical Joints Subjected to Eccentric Loads

Jie Lu,Hongbo Liu,Zhi-Hua Chen 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.2

Welded hollow spherical joints are widely used as a connection pattern in space lattice structures. Understanding the postfi re residual behavior of welded hollow spherical joints is crucial for fi re damage assessment of the space lattice structures. However, the post-fi re behavior of welded hollow spherical joints has not been explored in existing studies. In this paper, experimental and numerical studies were conducted to investigate the residual behavior of eccentrically loaded welded hollow spherical joints after fi re exposure. Eccentric compressive tests were performed on fi ve joint specimens after exposure to the ISO-834 standard fi re (including both heating and cooling phases), and three highest fi re temperatures, i.e., 600, 800, and 1000 °C, were considered. The temperature distributions in the specimens during the heating and cooling process and the related mechanical behavior of the specimens, such as load versus longitudinal displacement and rotation responses, load-bearing capacities, and strain distributions, were obtained and analyzed. Finite element analysis (FEA), including both heat transfer and mechanical analysis, were also developed using the ABAQUS software. Having validated the FE models against the experimental results, a design method was proposed on the basis of parametric studies to predict the residual load-bearing capacity of eccentrically loaded welded hollow spherical joints after fi re exposure.

Aberrant DNA Methylation of P16, MGMT, and hMLH1 Genes in Combination with MTHFR C677T Genetic Polymorphism and Folate Intake in Esophageal Squamous Cell Carcinoma

Chen, Jing,Huang, Zhi-Jie,Duan, Yu-Qin,Xiao, Xin-Rong,Jiang, Jian-Qing,Zhang, Ru Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Aim: The present case-control study was conducted to explore the association of MTHFR gene polymorphism and relations of P16, MGMT and HMLH1 to MTHFR and folate intake. Methods: A total of 257 cases of esophageal squamous cell carcinoma confirmed by histopathological examination were collected. Genotyping of P16, MGMT and HMLH1 was accomplished by methylation-specific polymerase chain reaction (PCR) after sodium bisulfate modification of DNA and the MTHFR C677T genetic polymorphism was detected by PCR-restriction fragment-length polymorphism (PCR-RFLP). Results: The proportions of DNA hypermethylation in P16, MGMT and hMLH1 in cancer tissues were significantly higher than in paracancerous normal tissue. The proportion of hypermethylation in at least one gene was 88.5% in cancer tissue, and was also significantly higher than that in paracancerous normal tissue. Our finding showed individuals with homozygotes (TT) of MTHFR C677T had significant risk of DNA hypermethylation of MGMT in cancer tissues, with an OR (95% CI) of 3.15 (1.12-6.87). Similarly, patients with high intake of folate also showed a slight high risk of DNA methylation of MGMT, with OR (95% CI) of 2.03 (1.05-4.57). Conclusion: Our study found the P16, MGMT and hMLH1 demonstrate a high proportion of hypermethylation in esophageal squamous cell cancer cancer tissues, which might be used as biomarkers for cancer detection.

Glulathione-S-transferases Gene Polymorphism in Prediction of Gastric Cancer Risk by Smoking and Helicobacter Pylori Infection Status

Jing, Chen,Huang, Zhi-Jie,Duan, Yu-Qin,Wang, Pei-Hong,Zhang, Ru,Luo, Ke-Shu,Xiao, Xin-Rong Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Aim: To evaluate the association of glutathione S-transferases gene polymorphisms with the risk of gastric cancer, with reference to smoking and Helicobacter pylori infection. Methods: We conducted a 1:1 matched case-control study with 410 gastric cancer cases and 410 cancer-free controls. Polymorphisms of GSTM1, GSTT1 and GSTP1 were determined using PCR-CTPP. Results: The GSTM1 and GSTT1 null genotypes were significantly associated with the risk of gastric cancer after adjusting for potential confounding factors (OR=1.68, 95% CI=1.32-2.23 for null GSTM1, OR=1.73; 95% CI=1.24-2.13 for null GSTT1). The combination of null GSTM1 and null GSTT1 conferred an elevated risk (OR=2.54, 95% CI=1.55-3.39). However, no association was found for GSTP1 polymorphism The smoking modified the association of GSTM1 and GSTT1 null genotypes with the risk of gastric cancer. Conclusion: GSTM1 and GSTT1 null genotypes are associated with increased risk of gastric cancer, and smoking modifies the association.

Evaluation and Comparison of the Solubility Models for Solute in Monosolvents

Min-jie Zhi,Wan-feng Chen,Yang-bo Xi 한국화학공학회 2024 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.62 No.1

The solubility of Cloxacillin sodium in ethanol, 1-propanol, isopropanol, and acetone solutions was measured at different temperatures. The melting property was also tested by using a differential scanning calorimeter (DSC). Then, the solubility data were fitted using Apelblat equation and λh equation, respectively. The Wilson model and NRTL model were not utilized to correlate the test data, since Cloxacillin sodium will decompose directly after melting. For comparison purposes, the four empirical models, i.e., Apelblat equation, λh equation, Wilson model and NRTL Model, were evaluated by using 1155 solubility curves of 103 solutes tested under different monosolvents and temperatures. The comparison results indicate that the Apelblat equation is superior to the others. Furthermore, a new method (named the calculation method) for determining the Apelblat equation using only three data points was proposed to solve the problem that there may not be enough solute in the determination of solubility. The log-logistic distribution function was used to further capture the trend of the correlation and to make better quantitative comparison between predicted data and the experimental ones for the Apelblat equation determined by different methods (fitting method or calculation method). It is found that the proposed calculation method not only greatly reduces the number of test data points, but also has satisfactory prediction accuracy.

Effect of Light with Different Wavelengths on Nostoc flagelliforme Cells in Liquid Culture

( Yu Jie Dai ),( Jing Li ),( Shu Mei Wei ),( Nan Chen ),( Yu Peng Xiao ),( Zhi Lei Tan ),( Shi Ru Jia ),( Nan Nan Yuan ),( Ning Tan ),( Yi Jie Song ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.4

The effects of lights with different wavelengths on the growth and the yield of extracellular polysaccharides of Nostoc flagelliforme cells were investigated in a liquid cultivation. N. flagelliforme cells were cultured for 16 days in 500 ml conical flasks containing BG11 culture medium under 27 μmol·m-2·s-1 of light intensity and 25oC on a rotary shaker (140 rpm). The chlorophyll a, phycocyanin, allophycocyanin, and phycoerythrin contents in N. flagelliforme cells under the lights of different wavelengths were also measured. It was found that the cell biomass and the yield of polysaccharide changed with different wavelengths of light. The biomass and the yield of extracellular polysaccharides under the red or violet light were higher than those under other light colors. Chlorophyll a, phycocyanin, and allophycocyanin are the main pigments in N. flagelliforme cells. The results showed that N. flagelliforme, like other cyanobacteria, has the ability of adjusting the contents and relative ratio of its pigments with the light quality. As a conclusion, N. flagelliforme cells favor red and violet lights and perform the complementary chromatic adaptation ability to acclimate to the changes of the light quality in the environment.

Identification and Association of SNPs in TBC1D1 Gene with Growth Traits in Two Rabbit Breeds

Yang, Zhi-Juan,Fu, Lu,Zhang, Gong-Wei,Yang, Yu,Chen, Shi-Yi,Wang, Jie,Lai, Song-Jia Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.11

The TBC1D1 plays a key role in body energy homeostasis by regulating the insulin-stimulated glucose uptake in skeletal muscle. The present study aimed to identify the association between genetic polymorphisms of TBC1D1 and body weight (BW) in rabbits. Among the total of 12 SNPs detected in all 20 exons, only one SNP was non-synonymous (c.214G>A. p.G72R) located in exon 1. c.214G>A was subsequently genotyped among 491 individuals from two rabbit breeds by the high-resolution melting method. Allele A was the predominant allele with frequencies of 0.7780 and 0.6678 in European white rabbit (EWR, n = 205) and New Zealand White rabbit (NZW, n = 286), respectively. The moderate polymorphism information content (0.25<PIC<0.50) was present in both breeds. The association analysis revealed that genotypes GA and AA had higher 35 d body weight (BW) than genotype GG in both EWR (p<0.01) and NEW (p<0.05). For the 56 d BW and 70 d BW traits, genotypes AA and GA were higher than genotype GG in both two breeds, the difference was not significant (p>0.05). Our results implied that the c.214G>A of TBC1D1 gene might be one of the candidate loci affecting the trait of 35 d BW in the rabbit.

Isoprenaline Induces Periostin Expression in Gastric Cancer

Lin Chen,Guo-Xiao Liu,Hong-Qing Xi,Xiao-Yan Sun,Zhi-Jun Geng,Shao-Wei Yang,Yan-Jie Lu,Bo Wei 연세대학교의과대학 2016 Yonsei medical journal Vol.57 No.3

Purpose: Periostin mediates critical steps in gastric cancer and is involved in various signaling pathways. However, the roles of periostin in promoting gastric cancer metastasis are not clear. The aim of this study was to investigate the relevance between periostinexpression and gastric cancer progression and the role of stress-related hormones in the regulation of cancer development and progression. Materials and Methods: Normal, cancerous and metastatic gastric tissues were collected from patients diagnosed with advanced gastric cancer. The in vivo expression of periostin was evaluated by in situ hybridization and immunofluorescent staining. Meanwhile,human gastric adenocarcinoma cell lines MKN-45 and BGC-803 were used to detect the in vitro expression of periostin by using quantitative real-time polymerase chain reaction (PCR) and western blotting. Results: Periostin is expressed in the stroma of the primary gastric tumors and metastases, but not in normal gastric tissue. In addition,we observed that periostin is located mainly in pericryptal fibroblasts, but not in the tumor cells, and strongly correlated to the expression of α-smooth muscle actin (SMA). Furthermore, the distribution patterns of periostin were broader as the clinical staging of tumors progressed. We also identified a role of stress-related signaling in promoting cancer development and progression,and found that isoprenaline upregulated expression levels of periostin in gastric cancer cells. Conclusion: These findings suggest that the distribution pattern of periostin was broader as the clinical staging of the tumor progressedand found that isoprenaline upregulated expression levels of periostin in gastric cancer cells.