Fixed Time Event-triggered Tracking Control for Interconnected Nonlinear Uncertain Systems: An Observer-based Approach

Panpan Yang,Xingwen Chen,Xiangmo Zhao,Maode Yan 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

The fixed time event-triggered tracking control for interconnected nonlinear uncertain systems, whose state variables are unmeasurable, is investigated via an observer-based approach. The unmeasurable states are estimated by the designed neural observer under the fixed time stability criterion, and the uncertain interconnections are compensated by a smooth function. Then, a novel tracking error-based event-triggered strategy is employed to reduce the communication frequency of the control signal. By means of radial basis function (RBF) neural networks (NNs) to approximate the unknown nonlinearities, a fixed time event-triggered controller is designed to guarantee the convergence of tracking error to the origin in a fixed time. Finally, the proposed technique is verified by some numerical simulations.

Analysis of Global Sagittal Postural Patterns in Asymptomatic Chinese Adults

Panpan Hu,Miao Yu,Zhuoran Sun,Weishi Li,Liang Jiang,Feng Wei,Xiaoguang Liu,Zhongqiang Chen,Zhongjun Liu 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.2

Study Design: A prospective imaging study. Purpose: To characterize the distribution of the global sagittal postural patterns in asymptomatic Chinese adults using Roussouly classification. Overview of Literature: The norms of sagittal parameters in asymptomatic Chinese population have been previously described, but no report described their global sagittal postural patterns as characterized by Roussouly classification. Methods: A cohort of 272 asymptomatic Chinese adults was recruited. Data was assimilated by reviewing the films for each subject. Sagittal parameters were measured and sagittal postural patterns were then determined according to Roussouly classification. The pattern distributions were compared across genders within the study cohort. We also compared the data across different ethnicities from our study and a previous study to further characterize Chinese sagittal postures. Results: The cohort included 161 males and 111 females, with mean age of 23.2±4.4 years. The average descriptive results were as below: pelvic incidence (PI) 46.4°±9.6°, thoracic kyphosis (TK) 24.2°±9.0°, lumbar lordosis (LL) 50.6°±10.6°, sacral slope (SS) 37.2°±7.6°, pelvic tilt (PT) 9.4°±6.8°, spinosacral angle (SSA) 131.1°±7.5° and sagittal vertical axis (SVA) 17.24±32.36 mm. Despite a significant difference between two genders in LL, PI, SSA, and SVA, no difference was found in the distribution of Roussouly types among them. 47.8% of our cohort belonged to Roussouly type 3, while type 1, 2 and 4 comprised 23.2%, 14.0% and 15.1% of the subjects, respectively. Roussouly classification was capable of categorizing sagittal parameters except for the PT. This study also found that 4.4% of the recruited subjects belonged to the C7-anterior subgroup. Conclusions: From a characterization of the sagittal postural patterns of asymptomatic Chinese adults using Roussouly classification, the distribution was similar between Chinese males and females; however, from a cross-study comparison, it was different between asymptomatic Chinese and Caucasian adults, with a higher proportion of Roussouly type 3 in Chinese adults.

Potential rocky desertification simulation for the karst plateau area using CA-Markov model

Panpan Zhang,Yuanman Hu,Duning Xiao,Xiuzhen Li,Jie Yin 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

It has been recognized that karst rocky desertification is one of the most serious geo-ecological problem in Southwestern China. Understanding the development trend of karst rocky desertification is of fundamental importance in rocky desertification management and control. More attention should be paid to karst areas with potential rocky desertification. In this paper, ARFGIS software was used to discribe the historical and current situation of potential rocky desertification spatial pattern in the middle and lower reaches of houzhai stream, a typical karst plateau area. Remote sensing images from the study area, Remote sensing images from the study area, collected in 1987,1955 and 2004 were used for spatial pattern simulation of potential rocky desertification subdivided into six types: none, extreme slightly, slightly, moderately, severely and extreme severely. The result showed that the potential rocky desertification landscape distributed unevenly; a little more than half of the are showed gradual rocky desertification trend and about 60% of those regions had emarkable rocky desertification trend; Slightly potential rocky desertification was increasing all the time, while the other five types of potential rocky desertification had different change tendencies during different states. Then based on CA-Markov model, the potential rocky desertification spatial pattern was predicted. Verification with investigation based on map in 2004 indicated that 87.2% of the simulation was consistant with real data. therefore the model is robust in prediction potential rocky desertification spatial pattern in this study area.

MODULATION OF PTCDA NANOSTRUCTURE AND OPTICAL PROPERTY: DEPENDENCE ON GROWTH TEMPERATURE

PANPAN GUO,FAQIANG XU,Wenhua Zhang,LINGYUN LIU,KAI WANG,YUYAN HAN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.6

3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) nanostructures with di®erent mor-phologies are prepared on glass substrates at di®erent substrate temperature ( T s Þ in a molecularbeam epitaxy (MBE) system. Scanning/transmission/scanning transmission electron microscopy(SEM/TEM/STEM), X-ray di®raction (XRD), selected area electron di®raction (SAED) andnanobeam di®raction (NBD) techniques are employed in the systematical characterizations of thenanostructures. It is found that the PTCDA nanosheets (NSs), nanowires and nanorods are facileto produce at T s ¼ 350?C, 330?C and 240?C, respectively; the continuous ¯lms are obtained at180?C and 50?C. XRD studies indicate that only the ? -phase polymorph is formed regardless ofthe T s. SAED and NBD results show that the nanowire and NS are single crystalline. The opticalproperties of the prepared PTCDA nanostructures are also found to be in°uenced by T s and arecorrelated with the crystal quality and size. PTCDA nanowires and NSs exhibit an obviousredshift and broadening in the adsorption spectra, and enhanced emission intensity. Theimproved optical properties facilitate potential applications of these nanostructures in organicoptoelectronic devices.

Enhancement of Gas Permeability for CH4/N2 Separation Membranes by Blending SBS to Pebax Polymers

Panpan Guan,Jujie Luo,Wei Li,Ziqin Si 한국고분자학회 2017 Macromolecular Research Vol.25 No.10

Three poly(ether-b-amide) (Pebax) membranes with different polyamide (PA) contents were prepared to study CH4/N2 gas separation property. The increase in CH4 and N2 gas permeability was observed with the lowering of PA content. It was attributed to the decreased fraction of impermeable crystalline PA regions and the decrease in the crystallinity of the semi-crystalline PA phase of Pebax membranes. This result is consistent with the previous reports on other gases for Pebax membranes. To lower the crystallinity and higher the CH4 permeability, 10wt% poly(styrene-b-butadiene-b-styrene) (SBS) block copolymer was blended with Pebax. For single gas permeation test, we demonstrated that CH4 permeability of the Pebax/SBS blend membrane is 60% higher than that of Pebax, reaching 106 Barrer at 55 °C. In CH4 and N2 mixed gas permeation test, up to 26 vol% of CH4 could be obtained from passing 10 vol% CH4 of CH4/N2 mixed gas through the Pebax/SBS membranes, demonstrating that Pebax based membranes could potentially be applied to the enrichment of CH4 for the coal-bed methane (CBM).

RESEARCH ARTICLES : Gene-Based Markers for the Tomato Yellow Leaf Curl Virus Resistance Gene Ty-3

( Panpan Dong ),( Koeun Han ),( Muhammad Irfan Siddique ),( Jin Kyung Kwon ),( Meiai Zhao ),( Fu Wang ),( Byoung Cheorl Kang ) 한국육종학회 2016 Plant Breeding and Biotechnology Vol.4 No.1

The viral disease induced by Tomato yellow leaf curl virus (TYLCV) reduces tomato (Solanum lycopersicum) yield significantly in tropical and subtropical regions. A number of loci, including Ty-1 to Ty-5, conferring resistance to TYLCV have been described and introgressed into modern tomato cultivars. The availability of molecular markers linked to these genes would expedite the introgression of TYLCV resistance into commercial cultivars. In the present study, we developed gene-based markers linked to the Ty-3 gene using a segregating population derived from a cross between the TYLCV-resistant line S. lycopersicum ‘A45’ and the susceptible line S. lycopersicum ‘A39’. Agrobacterium-mediated screening was used to test TYLCV resistance of plants in the segregating population, and the resistance was evaluated by a visual scoring method and polymerase chain reaction analysis. By comparing sequences of the Ty-3 genes of the resistant and susceptible lines, two high-resolution melting (HRM) markers (Ty3-HRM1 and Ty3-HRM2) and one sequence characterized amplified region (SCAR) marker (Ty3-SCAR1) were developed. The HRM markers were based on single nucleotide polymorphisms at the 13th exon and the 15th intron, whereas the SCAR marker was based on a 246-bp deletion in the 16th intron. These gene-based markers will be useful tools for marker-assisted selection in breeding programs to improve TYLCV resistance of tomato.

Fabrication of dual-coated graphene oxide nanosheets by polypyrrole and poly(ionic liquid) and their enhanced electrorheological responses

Panpan Chen,Qianqian Cheng,Li-Min Wang,Ying Dan Liu,최형진 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.69 No.-

A two-dimensional composite material, poly(ionic liquid)-modified graphene oxide/polypyrrole (GO/PPy/PIL) multilayered nanosheets, was fabricated and applied as a new electrorheological (ER) material. The morphological differences between the single- and dual-coated nanosheets were confirmed using scanning electron microscopy and transmission electron microscopy. Rheological properties measured using a rotational rheometer indicated that the GO/PPy/PIL composite nanosheets exhibited relatively high ER effect under a certain electric field strength than the GO/PPy nanosheets because of the universal PIL second coating. The dual-coated nanosheets also showed a higher applicable electric field strength due to the semiconductive properties of the thick PIL layer.

A Novel Control Algorithm for the Self-organized Fission Behavior of Flocking System with Time Delay

Panpan Yang,Mingyong Liu,Xiaokang Lei,Cheng Song 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.4

This paper studies the self-organized fission control problem for flocking system with time delay. Bothconstant and time-varying time delay cases are considered. Firstly, a novel information coupling degree (ICD) basedfission control algorithm, which is able to split a coherent flock into multiple sub-groups under conflict externalstimuli, is proposed. Then, for the case of constant time delay, the sufficient conditions for the fission controlalgorithm is derived using Lyapunov-Razumikhin theorem. For the case of time-varying time delay, Lyapunov-Krasovskii functional method is adopted to obtain the sufficient conditions for the fission control algorithm in termsof linear matrix inequalities (LMIs). Finally, numerical simulations are provided to illustrate the effectiveness ofthe theoretical results.

Separation of Rh(III) from the Mixed Chloride Solutions Containing Pt(IV) and Pd(II) by Extraction with Alamine336

Panpan Sun,Myungho Lee,이만승 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.7

Solvent extraction experiments of Pt(IV), Pd(II) and Rh(III) by Alamine336 were performed from the mixed chloride solutions. In the HCl concentration range from 1 to 5 M, most of Pt and Pd were extracted from the mixed solutions. However,the extraction percentage of Rh was much smaller than that of Pt and Pd. Lower concentration of Alamine336 in strong HCl solution led to higher separation factor of Rh from Pt and Pd. Adding SnCl2 to the mixed solutions increased the extraction percentage of Rh, while the extraction percentage of Pt and Pd was little affected. Our results showed that selective separation of Rh or coextraction of the three platinum group metals from the mixed solution would be possible by adjusting the extraction conditions.

Consensus Based Control Algorithm for Nonlinear Vehicle Platoons in the Presence of Time Delay

Panpan Yang,Ye Tang,Maode Yan,Xu Zhu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.3

The platoon control problem for nonlinear vehicles in the presence of time delay is investigated in thispaper, where both constant time delay and time-varying delay cases are considered. A linearized third-order vehicledynamic model is firstly derived by deploying the exact feedback linearization technique and the vehicle platooncontrol problem is converted into a consensus-seeking problem. Then, a consensus based vehicle platoon controlalgorithm with time delay is proposed, which drives vehicles to form an equally spaced platoon with the samevelocity. By deploying the Lyapunov-Razumikhin theorem, the upper bound of time delay for vehicle platoon withconstant time delay is derived and the sufficient conditions that guarantee the stability of the vehicle platoon areobtained. Meanwhile, the sufficient conditions that ensure the stability of vehicle platoon with time-varying delayare acquired via the Lyapunov-Krasovskii theorem. Numerical demonstrations verify the feasibility and correctnessof the theoretical results.