중국의 도시형 자기부상열차 개발과 상용화 현황

Guobin Lin,한형석 한국철도학회 2014 철도저널 Vol.17 No.6

Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets

Guobin Luo,Wenbin Xu,Jinshan Yang,Yang Li,Liyang Zhang,Yizhen Wang,Cong Lin,Yonggen Zhang 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.5

Objective: This trial was performed to examine the effects of ruminally degradable starch (RDS) levels in total mixed ration (TMR) with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Methods: Eight multiparous Holstein cows (body weight [BW]: 717±63 kg; days in milk [DIM]: 169±29) were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS) or 72.1% ruminally degradable starch (% of total starch, high RDS). Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. Results: The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Conclusion: Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

Fuzzy adaptive control particle swarm optimization based on T-S fuzzy model of maglev vehicle suspension system

Chen Chen,Junqi Xu,Guobin Lin,Yougang Sun,Dinggang Gao 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.1

At present, with the gradual promotion of Maglev vehicles, the stability of the suspension system has gradually become a hotspot. During the operation of Maglev vehicles, vibration may be caused by external disturbances such as track irregularity, non-directional wind load and load variation. When the vibration amplitude is within the controllable range of the current parameters, the restraint effect can be achieved and the stable convergence can be formed. However, when the vibration amplitude exceeds the current controllable range, the maglev vehicle may break the track or even lose stability. In order to solve the possible adverse effects of external disturbances on the stability of the system, a T-S fuzzy model considering both parameter uncertainties and external disturbances is constructed, and a relatively mature fuzzy adaptive control method is used for suspension control. However, considering the tracking performance of the system control parameters and the response speed of the parameter changes when the external disturbance changes, the particle swarm optimization (PSO) algorithm is used to optimize the system. The effectiveness of the optimized fuzzy adaptive control law in coordinating the closed-loop stability of the suspension system is proved in terms of response speed and convergence performance. Based on linear matrix inequality (LMI), the control response region satisfying the control performance after optimization is defined, and Lyapunov method is adopted to prove the stability of the optimized algorithm in controlling vehicle fluctuation operation. The simulation and experimental results show that the fuzzy adaptive control algorithm optimized by particle swarm optimization can further improve the speed of parameter optimization and the tracking performance of the system in the face of external disturbances and internal system parameter perturbations within a given range of control parameters. Compared with previous control strategies, the controller can greatly improve the response speed and the closed-loop information updating ability of the system in the face of disturbances, so that the system has stronger robustness and faster dynamic response.

Multiple damage detection of maglev rail joints using time-frequency spectrogram and convolutional neural network

Yi-Qing Ni,Su-Mei Wang,Gao-Feng Jiang,Yang Lu,Guobin Lin,Hong-Liang Pan,Junqi Xu,Shuo Hao 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.4

Maglev rail joints are vital components serving as connections between the adjacent F-type rail sections in maglev guideway. Damage to maglev rail joints such as bolt looseness may result in rough suspension gap fluctuation, failure of suspension control, and even sudden clash between the electromagnets and F-type rail. The condition monitoring of maglev rail joints is therefore highly desirable to maintain safe operation of maglev. In this connection, an online damage detection approach based on three-dimensional (3D) convolutional neural network (CNN) and time-frequency characterization is developed for simultaneous detection of multiple damage of maglev rail joints in this paper. The training and testing data used for condition evaluation of maglev rail joints consist of two months of acceleration recordings, which were acquired in-situ from different rail joints by an integrated online monitoring system during a maglev train running on a test line. Short-time Fourier transform (STFT) method is applied to transform the raw monitoring data into time-frequency spectrograms (TFS). Three CNN architectures, i.e., small-sized CNN (S-CNN), middle-sized CNN (M-CNN), and large-sized CNN (L-CNN), are configured for trial calculation and the M-CNN model with excellent prediction accuracy and high computational efficiency is finally optioned for multiple damage detection of maglev rail joints. Results show that the rail joints in three different conditions (bolt-loosenesscaused rail step, misalignment-caused lateral dislocation, and normal condition) are successfully identified by the proposed approach, even when using data collected from rail joints from which no data were used in the CNN training. The capability of the proposed method is further examined by using the data collected after the loosed bolts have been replaced. In addition, by comparison with the results of CNN using frequency spectrum and traditional neural network using TFS, the proposed TFSCNN framework is proven more accurate and robust for multiple damage detection of maglev rail joints.

Dual-Responsive Cross-Linked Micelles from Amphiphilic Four-Arm Star Copolymers with Different Block Ratios for Triggering DOX Release

Yunwei Huang,Yanzhe Li,Zilun Tang,Qiuping Su,Tingting Liao,Yuxin Gu,Xiaofeng Lin,Xihong Zu,Wenjing Lin,Guobin Yi 한국고분자학회 2020 Macromolecular Research Vol.28 No.8

The four-arm star copolymers poly(methacrylic acid)-poly(2-hydroxyethyl methacrylate-disulfide~)-poly(poly(ethylene glycol) methyl ether methacrylate) (4AS-PMAAx-(PHEMA-SS~)y-PPEGMAz) with four different block ratios were synthesized and could self-assembled into cross-linked polymer micelles for the exploration of the structure-property relationship. The cross-linked polymer micelles in aqueous solution had low critical micelle concentration (CMC) values (1.9-4.6 mg/L), which exhibited better stability than non-cross-linked micelles. The CMC value decreased with the increase of the length of inner PMAA core and hydrophobic PHEMA cross-linked middle layer. The blank and doxorubicin (DOX)- loaded micelles with different block ratios were prepared by dialysis with the particle sizes of 120-240 nm. The longer inner PMAA core and cross-linked middle layer enhanced the drug loading content (DLC) results and led to relatively bigger particle sizes of polymer micelles. The in vitro DOX release data revealed that DOX-loaded micelles had low DOX cumulative release percentages of 18-37% after 110 h at pH 7.4, but up to 83-90% when introducing reductant GSH at pH 5.0. The 4AS-PMAA21.2-(PHEMASS~) 13.1-PPEGMA5.1 micelles with the longest PMAA core had the largest cumulative release of 90.1%. The DOX release process and mechanism of the micelles at different conditions fitted well with the semi-empirical equation. Overall, the results demonstrated that the block ratios and pH/redox-responsiveness of these four-arm star copolymers could be well-controlled and their self-assembled cross-linked micelles as anticancer drug carrier system could be improved by optimizing the different ratios.