Study on the Influence of Parallel Fuzzy PID Control on the Regulating System of a Bulb Tubular Turbine Generator Unit

Wang Rongxin,An Aimin,Wen Yongan,Song Houbin 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

This article presents a parallel fuzzy PID control strategy on a bulb tubular turbine generator unit for improving the robust control performance. First, the nonlinear model of a bulb tubular turbine generator unit is built in MATLAB/Simulink, and the PID controller parameters are adjusted under rated head. Then, an integrated fuzzy logic PID controller is designed to regulate the hydraulic turbine unit. The eff ectiveness and robustness capability of the proposed controller are evaluated in four independent experiments: starting process, load rejection, frequency tracking and frequency interference. The experimental results validate that the proposed controller can signifi cantly improve the response performance of the speed of hydraulic turbine units. The coeffi cient mutation experiment reveals that the robustness of the system has been improved obviously, and unique contributions of the work can provide a reference for the optimal control of bulb tubular turbine generator units.

Numerical Investigation of Cracks at Girder Ends of Prefabricated Post-Tensioned Prestressed Concrete I-Girders

Aimin Yuan,Tongyi Wang,Jinjian Gu,Xinge Miao,Jianrong Xu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

Prefabricated post-tensioned prestressed concrete (PTC) girders with high degrees of prestressing have been developed continuously in recent bridge designs to reach longer spans, higher quality, and larger load-bearing capacity. However, during the prefabrication process, several inclined and horizontal cracks were observed at the ends of a new style post-tensioned concrete girder, which could have a negative impact on the girders' longevity. In this study, a nonlinear finite element analysis technique was utilized to illustrate how concrete reacts and the mechanisms behind typical cracking patterns during the actual post-tensioning sequence. The prestressing load of a PTC girder was simulated with an improved cooling temperature method that accounts for immediate prestress losses. The field of principle tensile strain patterns and primary strain trajectories explained the overall mechanism underlying typical cracking behaviors. The results showed that the horizontal cracks under the anchorage plate (behavior 1) were generated by the bursting force, whereas the inclined cracks (behavior 2) and the horizontal cracks between the strands N1 and N2 anchor plates (behavior 3) were caused due to the spalling force. The effects of self-weight, girder end forms, as well as the transfer length of the prestressing strands, were discussed. The result demonstrates that both the self-weight and girder end shapes have a considerable effect on the behaviors of the anchorage zone. It is suggested that the transfer length of the anchor head be greater than 26 times of strand diameter to achieve the same effective stresses as the theoretical values.

Crystallization and Mechanical Properties of Glass Fiber Reinforced Polypropylene Composites Molded by Rapid Heat Cycle Molding

Aimin Zhang,Guoqun Zhao,Jialong Chai,Junji Hou,Chunxia Yang,Guilong Wang 한국섬유공학회 2020 Fibers and polymers Vol.21 No.12

The crystalline behavior and mechanical properties of PP/GF (glass fibers) composites molded by rapid heat cyclemolding (RHCM) and conventional injection molding (CIM) were compared. SEM, DSC and XRD were utilized to studycrystallization behavior of PP and PP/GF composites. Furthermore, universal testing machine was employed to investigatethe mechanical properties. Results proved that higher degree of crystallinity and larger crystal size can be obtained in RHCMin comparison to CIM. GF can induce more crystal nuclei and then reduce the crystal size due to shear stress which isgenerated in polymer matrix around fibers. Nucleating agent (NA) has a positive effect on refine grains. The average crystaldiameter of PP/NA/30 %GF is about 1.7 μm which is one-tenth of PP/30 %GF (14 μm) in RHCM. XRD tests illustrated thatα-form crystal is the main crystal type for PP and PP/GF composites in RHCM and CIM. However, there is a little β-formcrystal in RHCM for PP/GF composites without NA. NA accelerates the formation of α-form crystal and restrains theemergence of β-form crystal. The plastic parts obtained in RHCM exhibited higher strength and modulus compared with thatobtained in CIM for both tensile and flexural tests.

An Enzymolysis-Assisted Agrobacterium tumefaciens-Mediated Transformation Method for the Yeast-Like Cells of Tremella fuciformis

( Yuanyuan Wang ),( Danyun Xu ),( Xueyan Sun ),( Lisheng Zheng ),( Liguo Chen ),( Aimin Ma ) 한국균학회 2019 Mycobiology Vol.47 No.1

Agrobacterium tumefaciens-mediated transformation (ATMT), as a simple and versatile method, achieves successful transformation in the yeast-like cells (YLCs) of Tremella fuciformis with lower efficiency. Establishment of a more efficient transformation system of YLCs is important for functional genomics research and biotechnological application. In this study, an enzymolysis-assisted ATMT method was developed. The degradation degree of YLCs depends on the concentration and digestion time of Lywallzyme. Lower concentration (_0.1%) of Lywallzyme was capable of formation of limited wounds on the surface of YLCs and has less influence on their growth. In addition, there is no significant difference of YLCs growth among groups treated with 0.1% Lywallzyme for different time. The binary vector pGEH under the control of T. fuciformis glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter was utilized to transform the enzymolytic wounded YLCs with different concentrations and digestion time. The results of PCR, Southern blot, quantitative real-time PCR (qRT-PCR) and fluorescence microscopy revealed that the T-DNA was integrated into the YLCs genome, suggesting an efficient enzymolysis-assisted ATMT method of YLCs was established. The highest transformation frequency reached 1200 transformants per 10⁶ YLCs by 0.05% (w/v) Lywallzyme digestion for 15 min, and the transformants were genetically stable. Compared with the mechanical wounding methods, enzymolytic wounding is thought to be a tender, safer and more effective method.

Yet another Hybrid Strategy for Auto-tuning SpMV on GPUs

Zhaohui Wang,Xiaojie Qiu,Aimin Zhang,Yichao Cheng,Yi Peng,Sun Sun 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.5

Sparse matrix-vector multiplication (SpMV) is a key linear algebra algorithm and is widely used in many application domains. Besides multi-core architecture, there is also extensive research focusing on accelerating SpMV on many-core Graphics Processing Units (GPUs). SpMV computations have many indirect and irregular memory accesses, and load imbalance could occur while mapping computations onto single-instruction, multiple-data (SIMD) GPUs. SpMV is highly memory bandwidth-bound, though GPUs have massive computational resources, the performance of SpMV on GPUs is still unsatisfying. In this paper, we present a new hybrid strategy for auto-tuning SpMV on GPUs. Our strategy combines the advantages of row-major storage and column-major storage. Like many other strategies, we reordered a given sparse matrix according to row lengths in decreasing order. In order to be more adaptive and efficient, we proposed a new hybrid Blocked CSR and JDS (BCJ) format based on original CSR and JDS. BCJ splits a sparse matrix into a denser part and a sparser part after reordering and uses different kernels to process the corresponding part. And we proposed corresponding auto-tuning framework to help transforming matrix and launching kernels according to the sparsity characteristics of the matrix. A CUDA implementation of BCJ outperforms the original formats significantly on a broad range of unstructured sparse matrices.

A Rapid and Effective Colony PCR Procedure for Screening Transformants in Several Common Mushrooms

( Yuanyuan Wang ),( Danyun Xu ),( Dongmei Liu ),( Xueyan Sun ),( Yue Chen ),( Lisheng Zheng ),( Liguo Chen ),( Aimin Ma ) 한국균학회 2019 Mycobiology Vol.47 No.3

In the post-genomic era, gene function analysis has attracted much attention. Transformation is often needed to investigate gene function. In this study, an easy, rapid, reliable, and cost-effective colony polymerase chain reaction (PCR) method for screening mushroom transformants was developed: picking up a suitable amount of transformant’s tissue (1-10 lg) to 20 ll 0.25% Lywallzyme solution, and vortexing for 10 s followed by incubation at 34 ℃ for 15 min. Finally, 2 ll of the suspension was used as templates to perform PCR and single target bands were successfully amplified from respective transformants of Tremella fuciformis, Pleurotus ostreatus, and Pleurotus tuber-regium. This procedure could be widely employed for screening transformants in mushroom transformation experiments.

Synthesis of CNx nanocrystals and nanotubes on Co/Ni-covered substrate by nitrogen-atom-beam-assisted pulsed laser ablation

Ning Xu,Aimin Wu,Fuming Li,Hao Lin,Jiada Wu,Peinan Wang,Yuancheng Du,Zhifeng Ying 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.32

CNx nanocrystals and nanotubes were synthesized on Co/Ni-covered Si(100) wafers using a nitrogen-atom-beam-assisted pulsed laser ablation deposition method. Transimission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy showed that nanometer-sized CNx nanocrystals and nanotubes were contained in the as-deposited lms. The co-catalyzation by the cobalt and nickel in the synthesis process is considered to play an important role in the formation of CNx nanocrystals and nanotubes. The reasons for the formation of CNx nanocrystals and nanotubes have been analyzed.

Catalytic Ozonation of Phenol in Aqueous Solution by Co₃O₄ Nanoparticles

Dong, Yuming,Wang, Guangli,Jiang, Pingping,Zhang, Aimin,Yue, Lin,Zhang, Xiaoming Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.10

The degradation efficiencies of phenol in aqueous solution were studied by semi-continuous experiments in the processes of ozone alone, ozone/bulky $Co_3O_4$ and ozone/$Co_3O_4$ nanoparticles. Catalyst samples (bulky $Co_3O_4$ and $Co_3O_4$ nanoparticles) were characterized by X-ray diffraction and transmission electron microscopy. The Brunauer-Emmett-Teller surface area, $pH_{pzc}$ and the density of surface hydroxyl groups of the two catalyst samples were also measured. The catalytic activity of $Co_3O_4$ nanoparticles was investigated for the removal of phenol in aqueous solutions under different reaction temperatures. Tert-butyl alcohol had little effect on the catalytic ozonation processes. Based on these results, the possible catalytic ozonation mechanism of phenol by $Co_3O_4$ nanoparticles was proposed as a reaction process between ozone molecules and pollutants.

Rolling Bearing Incipient Fault Detection via Optimized VMD Using Mode Mutual Information

Shuai Tan,Aimin Wang,Hongbo Shi,Lei Guo 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.4

The complete failure of the rolling bearing is a deterioration process from the incipient weak fault to the severe fault, thus it is important to alarm when the incipient fault appear. This work presents a novel incipient bearing fault diagnosis framework using mode mutual information (MMI) based fitness function, variational mode decomposition (VMD), and cuckoo search (CS) algorithm. MMI based fitness function is proposed in order to obtain the optimal combinations of the VMD parameters. Therefore, the optimal parameters of VMD can be obtained by CS algorithm using proposed fitness function. Afterwards, a vibration signal is decomposed into a set of modes using the optimal VMD, and the kurtosis value of all modes are calculated. The envelop of the mode with maximum kurtosis value between modes and raw signal is computed as the input vector of the stacked denoised autoencoder (SDAE). Comparisons have been conducted via SDAE to evaluate the performance by using EMD and the fixedparameter VMD. The experimental results demonstrate that the proposed method is more effective in extracting the incipient bearing fault characteristics.

An Adjustable Sleep Scheduling Framework for WSN

Yanheng Liu,Lei Zhang,Aimin Wang,Dayang Sun 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.3