Modeling, Identification and Control of a Redundant Planar 2-DOF Parallel Manipulator

Yao-Xin Zhang,Shuang Cong,Wei-Wei Shang,Ze-Xiang Li,Shi-Long Jiang 대한전기학회 2007 International Journal of Control, Automation, and Vol.5 No.5

In this paper, the dynamic controller design problem of a redundant planar 2-dof parallel manipulator is studied. Using the Euler-Lagrange equation, we formulate the dynamic model of the parallel manipulator in the joint space and propose an augmented PD controller with forward dynamic compensation for the parallel manipulator. By formulating the controller in the joint space, we eliminate the complex computation of the Jacobian matrix of joint angles with end-effector coordinate. So with less computation, our controller is easier to implement, and a shorter sampling period can be achieved, which makes the controller more suitable for high-speed motion control. Furthermore, with the combination of static friction model and viscous friction model, the active joint friction of the parallel manipulator is studied and compensated in the controller. Based on the dynamic parameters of the parallel manipulator evaluated by direct measurement and identification, motion control experiments are implemented. With the experiments, the validity of the dynamic model is proved and the performance of the controller is evaluated. Experiment results show that, with forward dynamic compensation, the augmented PD controller can improve the tracking performance of the parallel manipulator over the simple PD controller.

A Fast Rough Mode Decision Algorithm for HEVC

Yao, Wei-Xin,Yang, Dan,Lu, Gui-Fu,Wang, Jun Korea Information Processing Society 2019 Journal of information processing systems Vol.15 No.3

HEVC is the high efficiency video coding standard, which provides better coding efficiency contrasted with the other video coding standard. But at the same time the computational complexity increases drastically. Thirty-five kinds of intra-prediction modes are defined in HEVC, while 9 kinds of intra prediction modes are defined in H.264/AVC. This paper proposes a fast rough mode decision (RMD) algorithm which adopts the smoothness of the up-reference pixels and the left-reference pixels to decrease the computational complexity. The three step search method is implemented in RMD process. The experimental results compared with HM13.0 indicate that the proposed algorithm can save 39.7% of the encoding time, while Bjontegaard delta bitrate (BDBR) is increased slightly by 1.35% and Bjontegaard delta peak signal-to-noise ratio (BDPSNR) loss is negligible.

A Fast Rough Mode Decision Algorithm for HEVC

Wei-Xin Yao,Dan Yang,Gui-Fu Lu,Jun Wang 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.3

HEVC is the high efficiency video coding standard, which provides better coding efficiency contrasted with theother video coding standard. But at the same time the computational complexity increases drastically. Thirtyfivekinds of intra-prediction modes are defined in HEVC, while 9 kinds of intra prediction modes are definedin H.264/AVC. This paper proposes a fast rough mode decision (RMD) algorithm which adopts the smoothnessof the up-reference pixels and the left-reference pixels to decrease the computational complexity. The three stepsearch method is implemented in RMD process. The experimental results compared with HM13.0 indicate thatthe proposed algorithm can save 39.7% of the encoding time, while Bjontegaard delta bitrate (BDBR) isincreased slightly by 1.35% and Bjontegaard delta peak signal-to-noise ratio (BDPSNR) loss is negligible.

A Fast Inter-prediction Mode Decision Algorithm for HEVC Based on Spatial-Temporal Correlation

Wei-Xin Yao,Dan Yang 한국정보처리학회 2022 Journal of information processing systems Vol.18 No.2

Many new techniques have been adopted in HEVC (High efficiency video coding) standard, such as quadtreestructuredcoding unit (CU), prediction unit (PU) partition, 35 intra-mode, and so on. To reduce computationalcomplexity, the paper proposes two optimization algorithms which include fast CU depth range decision andfast PU partition mode decision. Firstly, depth range of CU is predicted according to spatial-temporalcorrelation. Secondly, we utilize the depth difference between the current CU and CU corresponding to thesame position of adjacent frame for PU mode range selection. The number of traversal candidate modes isreduced. The experiment result shows the proposed algorithm obtains a lot of time reducing, and the loss ofcoding efficiency is inappreciable.

Caveolin-₁ is involved in high glucose accelerated human glomerular mesangial cell senescence

( Xin Feng ),( Wei Gao ),( Yao Li ) 대한내과학회 2017 The Korean Journal of Internal Medicine Vol.32 No.5

Background/Aims: We demonstrated the role of caveolin-₁ involved in high glu-cose (HG)-induced glomerular mesangial cells (GMCs) senescence. Methods: HG was used to stimulate GMCs. The telomere lengths were analyzed by Southern blot. β-Galactosidase staining was determined. The expressions of caveolin-1 and P₅₃ proteins were determined by Western blot. Results: Treatment with high concentrations of glucose induced GMC senescence accompanied by shortened telomere length and increase of β-galactosidase stain-ing as well as P₅₃ protein, which was abrogated after application of caveolin-₁- siRNA. Conclusions: This study proved that HG induced cell senescence in GMCs. The caveolin-₁ is involved in HG-induced mesangial cell senescence, and blocking ca-veolin-₁ significantly reduced cell senescence. The effect of caveolin-1 is mediated by P₅₃ pathway.

Numerical simulation of flow and heat transfer characteristic in straight-through labyrinth seals of aeroengines under eccentric and rotating conditions

Xin Wei,Zhaohui Yao,Feng Jin,Zhixiong Wang,Honghu Ji 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.6

In order to investigate the leakage and heat transfer of eccentric labyrinth seals, the flow and heat transfer process of eccentric and rotating straight-through labyrinth seals were numerically simulated. The research results show that the influence of eccentricity and rotation on the leakage coefficient is very small, and the change range is less than 2 %. Under the condition of non-eccentricity, the influence of rotating speed on the leakage coefficient depends on the rotating Taylor number. When the Taylor number is greater than 34.2, the leakage coefficient decreases slightly with the increase of rotating speed. At the same pressure ratio and rotating speed, the average Nusselt number of stator is greater than that of rotor. With the increase of eccentricty, the average Nusselt number of the section with larger clearance increases gradually, while the average Nusselt number of the section with smaller clearance decreases gradually.

Study of Increment Proportional Guidance Law for High Maneuvering Target

Yao Jun,Wei Zhou Fei,Wang Xin 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.6

For the inadequacies of the classical proportional navigation law, the mathematical model of increment proportional navigation law is established in this paper. According to the mathematical model comes to attacking targets uniform linear motion trajectory simulation. The trajectory simulation of classical proportional navigation law and incremental proportional navigation law about attacking high maneuvering target are compared. Simulation results show that incremental proportional navigation law can reduce the meet time, and stabilize the missile desired normal overload beating phenomenon in the end of the curve, also it can hit the high maneuvering target in the design requirements, and its performance is superior to classical proportional navigation law.

Performance and Applicability Analysis of Recognizing Microseismic Waveforms Using Neural Networks in Tunnel Engineering

Wei Zhang,Xin Bi,Lei Hu,Pengxiang Li,Zhibin Yao 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.2

The sudden and harmful nature of rockbursts in tunnels necessitates an accurate and applicable method for automatically recognizing rock fracture signals during rockburst microseismic (MS) monitoring. In this paper, the performance and applicability of recognizing MS waveforms using an artificial neural network (ANN) and a deep neural network (DNN) were studied in tunnels excavated by different methods. The results show that ANN performs very well in recognizing rock fracturing waveforms with a signal-to-noise ratio (SNR) ≥ 3 but has a low accuracy for those with an SNR < 3. The DNN also performs well for waveforms with SNR ≥3, and has a relatively high accuracy for waveforms with SNR < 3. The ANN model can be used in tunnels excavated by drilling and blasting (D&B) since there are fewer “small” rock fracturing events. The DNN model is applicable in tunnels excavated by the tunnel boring machine (TBM), recognizing more “small” events. In addition, the ANN model is a better choice, with fewer training samples at the initial stage of monitoring working. With continuous monitoring, the DNN model can be used to ensure and improve the accuracy. These results lay a foundation for automatic rockburst MS monitoring techniques in tunnel engineering.

GSTM1 Polymorphisms and Lung Cancer Risk in the Chinese Population: a Meta-Analysis Based on 47 Studies

Chen, Xin-Ping,Xu, Wei-Hua,Xu, Da-Feng,Xie, Xian-He,Yao, Jia,Fu, Sheng-Miao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Although a number of studies have been conducted on the association between GSTM1 polymorphisms and lung cancer in China, this association remains elusive and controversial. To clarify the effects of GSTM1 polymorphisms on the risk of lung cancer, a meta-analysis was performed in the Chinese population. Related studies were identified from PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM) up to 5th April 2014. A total of 45 articles (47 studies) including 6,623 cases and 7,865 controls were involved in this meta-analysis. Overall, a significant association (OR = 1.45, 95%CI: 1.32-1.60) was found between the null GSTM1 and lung cancer risk when all studies in Chinese population pooled into the meta-analysis. In subgroup analyses stratified by quality score, geographic area and source of controls, the same results were observed under all the models. This meta-analysis showed that the null GSTM1 may be a potential biomarker for lung cancer risk in Chinese, but further studies with gene-gene and gene-environment interactions are required for definite conclusions.

Construction of a genetic linkage map and QTL mapping of agronomic traits in Auricularia auricula-judae

Li-Xin Lu,Fang-Jie Yao,Peng Wang,Ming Fang,You-Min Zhang,Wei-Tong Zhang,Xiang-Hui Kong,Jia Lu 한국미생물학회 2017 The journal of microbiology Vol.55 No.10

Auricularia auricula-judae is a traditional edible fungus that is cultivated widely in China. In this study, a genetic linkage map for A. auricula-judae was constructed using a mapping population consisting of 138 monokaryons derived from a hybrid strain (A119-5). The monokaryotic parent strains A14-5 and A18-119 were derived from two cultivated varieties, A14 (Qihei No. 1) and A18 (Qihei No. 2), respectively. In total, 130 simple sequence repeat markers were mapped. These markers were developed using the whole genome sequence of A. auricula-judae and amplified in A14-5, A18- 119, and the mapping population. The map consisted of 11 linkage groups (LGs) spanning 854 cM, with an average interval length of 6.57 cM. A testcross population was derived from crossing between the monokaryon A184-57 (from the wild strain A184 as a tester strain) and the mapping population. Important agronomic trait-related QTLs, including mycelium growth rate on potato dextrose agar for the mapping population, mycelium growth rate on potato dextrose agar and sawdust for the testcross population, growth period (days from inoculation to fruiting body harvesting), and yield for the testcross population, were identified using the composite interval mapping method. Six mycelium growth raterelated QTLs were identified on LG1 and LG4, two growth period-related QTLs were identified on LG2, and three yieldrelated QTLs were identified on LG2 and LG6. The results showed no linkage relationship between mycelium growth rate and growth period. The present study provides a foundation for locating genes for important agronomic characteristics in A. auricula-judae in the future.