Research on Production Scheduling Optimization of Flexible Job Shop Production with Buffer Capacity Limitation Based on the Improved Gene Expression Programming Algorithm

Daliang Chang,Haibo Shi,Chao Han,Fu Meng 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.12

This study proposes a method to combine the improved gene expression programming (IGEP) and buffer-local scheduling to solve the optimization problem of flexible job shop production scheduling with buffer capacity limitation (BLFJSP). The IGEP algorithm was first used for the overall optimization and later combined with the flexible job shop production mode to design a multi-gene chromosome coding method to realize the overall optimization of the production schedule using the genetic biological evolution function. Furthermore, when the algorithm fell into a local extremum, the Jaccard similarity coefficient method was used to filter the approximate chromosomes, and the historical excellent chromosome backtracking method was used to increase the diversity of the population. Lastly, we designed the local scheduling rules of the job in and out of the buffer area. Based on the IGEP algorithm and considering the influence of buffer capacity limitation on the scheduling scheme, the final production scheduling scheme was generated by dual optimization methods aiming at minimizing blocking time and minimizing maximum completion time. Based on the actual production data of an assembly manufacturing company, multiple sets of simulation programs were designed to validate the IGEP algorithm for solving the optimization problem of BLFJSP.

Polystyrene-b-poly(oligo(ethylene oxide) Monomethyl Ether Methacrylate)-b-polystyrene Triblock Copolymers as Potential Carriers for Hydrophobic Drugs

You, Qianqian,Chang, Haibo,Guo, Qipeng,Zhang, Yudong,Zhang, Puyu Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.2

A simple and effective method is introduced to synthesize a series of polystyrene-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-b-polystyrene (PSt-b-POEOMA-b-PSt) triblock copolymers. The structures of PSt-b-POEOMA-b-PSt copolymers were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance ($^1H$ NMR) spectroscopy. The molecular weight and molecular weight distribution of the copolymer were measured by gel permeation chromatography (GPC). Furthermore, the self-assembling and drug-loaded behaviours of three different ratios of PSt-b-POEOMA-b-PSt were studied. These copolymers could readily self-assemble into micelles in aqueous solution. The vitamin E-loaded copolymer micelles were produced by the dialysis method. The micelle size and core-shell structure of the block copolymer micelles and the drug-loaded micelles were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The thermal properties of the copolymer micelles before and after drug-loaded were investigated by different scanning calorimetry (DSC). The results show that the micelle size is slightly increased with increasing the content of hydrophobic segments and the micelles are still core-shell spherical structures after drug-loaded. Moreover, the glass transition temperature (Tg) of polystyrene is reduced after the drug loaded. The drug loading content (DLC) of the copolymer micelles is 70%-80% by ultraviolet (UV) photolithography analysis. These properties indicate the micelles self-assembled from PSt-b-POEOMA-b-PSt copolymers would have potential as carriers for the encapsulation of hydrophobic drugs.

Polystyrene-b-poly(oligo(ethylene oxide) Monomethyl Ether Methacrylate)-b-polystyrene Triblock Copolymers as Potential Carriers for Hydrophobic Drugs

Qianqian You,Haibo Chang,Qipeng Guo,Yudong Zhang,Puyu Zhang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.2

A simple and effective method is introduced to synthesize a series of polystyrene-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-b-polystyrene (PSt-b-POEOMA-b-PSt) triblock copolymers. The structures of PSt-b-POEOMA-b-PSt copolymers were characterized by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopy. The molecular weight and molecular weight distribution of the copolymer were measured by gel permeation chromatography (GPC). Furthermore£¨the self-assembling and drug-loaded behaviours of three different ratios of PSt-b-POEOMA-b-PSt were studied. These copolymers could readily self-assemble into micelles in aqueous solution. The vitamin E-loaded copolymer micelles were produced by the dialysis method. The micelle size and core-shell structure of the block copolymer micelles and the drug-loaded micelles were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The thermal properties of the copolymer micelles before and after drug-loaded were investigated by different scanning calorimetry (DSC). The results show that the micelle size is slightly increased with increasing the content of hydrophobic segments and the micelles are still core-shell spherical structures after drug-loaded. Moreover, the glass transition temperature (Tg) of polystyrene is reduced after the drug loaded. The drug loading content (DLC) of the copolymer micelles is 70%-80% by ultraviolet (UV) photolithography analysis. These properties indicate the micelles self-assembled from PSt-b- POEOMA-b- PSt copolymers would have potential as carriers for the encapsulation of hydrophobic drugs.

Q-learning Algorithm Based Multi-Agent Coordinated Control Method for Microgrids

Yuanyuan Xi,Liuchen Chang,Meiqin Mao,Peng Jin,Nikos Hatziargyriou,Haibo Xu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper proposes a Q-learning algorithm (Q-LA) based multi-agent coordinated control method for microgrids. By the method, Q-LA is adopted to calculate the power to be regulated, which is called the microgrid regulation error (MRE), in secondary control for real-time operation. And the generation schedule of distributed generators (DGs) as well as batteries is modified in real time with the MRE by the fuzzy theory and particle swarm optimization method, taking the economy and environmental benefits into consideration together. The simulation platform of Q-LA based multi-agent hybrid energy management system for microgrid (HEMS-MG) is established in C++ Builder. The simulation results verify the effectiveness and feasibility of the proposed method.

A Single-Stage High Gain Current Source Inverter for Grid-Connected Photovoltaic System

Meiqin Mao,Yajun Zheng,Liuchen Chang,Haibo Xu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

The output voltage range of PV cells is widely influenced by the environment factors, such as temperature, solar radiation, etc. The lower output voltage of solar array can hardly meet the requirements for grid-connected operation of the system. To achieve high voltage gain and a steady ac output voltage in spite of the low dc input voltage, this paper presents a novel single-stage high gain current source inverter (CSI). The topology of the proposed inverter is derived from conventional tri-state current source inverter by introducing an impedance network with two symmetrical inductors and diodes separately. Theoretical analysis of operation modes and high voltage gain performance for the proposed inverter is presented, followed by the simulation of the proposed inverter in grid-connected photovoltaic (PV) system carried out on MATLAB.

Defect-Induced Epitaxial Growth for Efficient Solar Hydrogen Production

Zhang, Kan,Kim, Jung Kyu,Park, Bumsu,Qian, Shifeng,Jin, Bingjun,Sheng, Xiaowei,Zeng, Haibo,Shin, Hyunjung,Oh, Sang Ho,Lee, Chang-Lyoul,Park, Jong Hyeok American Chemical Society 2017 Nano letters Vol.17 No.11

<P>Epitaxial growth suffers from the mismatches in lattice and dangling bonds arising from different crystal structures or unit cell parameters. Here, we demonstrate the epitaxial growth of 2D MoS2 ribbon on 1D CdS nanowires (NWs) via surface and subsurface defects. The interstitial Cd-0 in the (1(2)over-bar10) crystal plane of the [0001]-oriented CdS NWs are found to serve as nucleation sites for interatomically bonded [001]-oriented MoS2, where the perfect lattice match (similar to 99.7%) between the(10(1)over-bar1) plane of CdS and the (002)-faceted in-plane MoS2 result in coaxial MoS2 ribbon/CdS NWs heterojunction. The coaxial but heterotropic epitaxial MoS2 ribbon on the surface of CdS NWs induces delocalized interface states that facilitate charge transport and the reduced surface state. A less than 5-fold ribbon width of MoS2 as hydrogen evolution cocatalyst exhibits a similar to 10-fold H-2 evolution enhancement than state of the art Pt in an acidi electrolyte, and apparent quantum yields of 79.7% at 420 nm 53.1% at 450 nm, and 9.67% at 520 nm, respectively.</P>