FROM QUANTITATIVE EXPANSION TO QUALITATIVE ENHANCEMENT:THEME TRANSFORMATION OF COMPULSORY EDUCATION IN RURAL CHINA

Yu-you QIN,Haibo YU 한국교육행정학회 2011 한국교육행정학회 학술연구발표회논문집 Vol.2011 No.2

Impulsive Output Consensus of Networked Passive Systems

Haibo Jiang,Liping Zhang,Jianjiang Yu,Caigen Zhou 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.6

In this paper, we study the problem of impulsive output consensus of multi-agent dynamical systems, where each agent is a passive system. Firstly, an impulsive control protocol is designed for networked passive systems based on the local information of agents. Secondly, sufficient conditions are derived to guarantee the output consensus of the multi-agent dynamical systems for the network with fixed and switching topologies, respectively. Finally numerical simulations are included to show the effectiveness of our theoretical results.

Consensus of Multi-agent Systems with Dead-zone Nonlinearity

Haibo Jiang,Liping Zhang,Jianjiang Yu,Caigen Zhou 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.4

In this paper, we investigate the consensus problem of multi-agent systems with dead-zone nonlinearity over undirected networks. Firstly, a control protocol is designed based on the local infor-mation of agents. Then by LaSalle’s invariance principle for non-smooth systems, we prove that if the undirected graph is connected then the consensus is achieved by the proposed control protocol. Sec-ondly, sufficient conditions are given to guarantee the consensus of multi-agent systems with dead-zone nonlinearity and switching topologies by Lyapunov method. Finally, numerical simulations show the effectiveness of our theoretical results.

Prediction of the Development of Pulmonary Fibrosis Using Serial Thin-Section CT and Clinical Features in Patients Discharged after Treatment for COVID-19 Pneumonia

Yu Minhua,Liu Ying,Xu Dan,Zhang Rongguo,Lan Lan,Xu Haibo 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.6

Objective: To identify predictors of pulmonary fibrosis development by combining follow-up thin-section CT findings and clinical features in patients discharged after treatment for COVID-19. Materials and Methods: This retrospective study involved 32 confirmed COVID-19 patients who were divided into two groups according to the evidence of fibrosis on their latest follow-up CT imaging. Clinical data and CT imaging features of all the patients in different stages were collected and analyzed for comparison. Results: The latest follow-up CT imaging showed fibrosis in 14 patients (male, 12; female, 2) and no fibrosis in 18 patients (male, 10; female, 8). Compared with the non-fibrosis group, the fibrosis group was older (median age: 54.0 years vs. 37.0 years, p = 0.008), and the median levels of C-reactive protein (53.4 mg/L vs. 10.0 mg/L, p = 0.002) and interleukin-6 (79.7 pg/L vs. 11.2 pg/L, p = 0.04) were also higher. The fibrosis group had a longer-term of hospitalization (19.5 days vs. 10.0 days, p = 0.001), pulsed steroid therapy (11.0 days vs. 5.0 days, p < 0.001), and antiviral therapy (12.0 days vs. 6.5 days, p = 0.012). More patients on the worst-state CT scan had an irregular interface (59.4% vs. 34.4%, p = 0.045) and a parenchymal band (71.9% vs. 28.1%, p < 0.001). On initial CT imaging, the irregular interface (57.1%) and parenchymal band (50.0%) were more common in the fibrosis group. On the worst-state CT imaging, interstitial thickening (78.6%), air bronchogram (57.1%), irregular interface (85.7%), coarse reticular pattern (28.6%), parenchymal band (92.9%), and pleural effusion (42.9%) were more common in the fibrosis group. Conclusion: Fibrosis was more likely to develop in patients with severe clinical conditions, especially in patients with high inflammatory indicators. Interstitial thickening, irregular interface, coarse reticular pattern, and parenchymal band manifested in the process of the disease may be predictors of pulmonary fibrosis. Irregular interface and parenchymal band could predict the formation of pulmonary fibrosis early.

Earth Pressure and Internal Forces of Tunnel Lining in Jet Grouting Reinforced Mud Stratum

Haibo Jiang,Shunhua Zhou,Honggui Di,Weitao Ye,Zhi Liu,Yu Zhao 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.10

In this study, field measurements of the earth pressures and the main reinforcement strains were carried out at three shield tunnel linings in mud stratum reinforced by vertical jet-grouted piles during tunnel construction and post-construction. The measured strains were used to back-calculate the linings' internal forces. The measured earth pressures and the back-calculated internal forces were compared to corresponding design values. The results indicate that the earth pressure and the internal forces increased rapidly, before exhibiting a fluctuating decrease and finally a long-term slow change, after lining assembly. The vertical jet-grouted piles were beneficial to mobilise the soil arching effect and led to the real earth pressure on the lining significantly smaller than the full overburden pressure, even with a relatively shallow buried depth. The vertical jet-grouted piles intensified the influence of backfill grouting on the earth pressure and caused the lining segments near the backfill grouting holes to continuously bear more radial pressure in the long-term. The resultant internal forces during lining assembly were large, and the Conventional Model failed to consider this element of the internal forces. The findings can provide a reference for the design and the construction of similar projects.

A high-resolution timescale for the Miocene Shanwang diatomaceous shale lagerstätte (China): development of Wavelet Scale Series Analysis for cyclostratigraphy

Jifeng Yu,Xinlong Pang,Wenzhao Fu,Jason Hilton,Mingmei Liang,Zongkai Jiang,Xiuli Zhao,Wenyan Qiao,Suo Shi,Diandong Zhang,Huitao Cao,Haibo Jia,Yadong Wang,Xiaoke Hu,Rui Zhang 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.5

The Miocene aged Shanwang Formation from the Shanwang National Geopark in China represents a succession of lacustrine diatomaceous shales containing an abundant and diverse biota with lagerstätte fossilization of soft tissues. To date, the Shanwang Formation has not been investigated for cyclostratigraphy nor has it been dated with high precision methods. Now we use thorium data as a paleoenvironmental and paleoclimatic proxy to conduct a detailed cyclostratigraphic analysis. A new and simple cyclostratigraphic method, Wavelet Scale Series Analysis (WSSA) is developed to recognize Milankovitch cycles. A total of three short eccentricity and fifteen precession cycles are identified; obliquity cycles are not apparent. In the sedimentary succession, the corresponding precession and short eccentricity cycles are 1.17 m and 4.98 m thick respectively, with this verified by Correlation Coefficient (COCO) analysis and Multitaper-Method (MTM) spectral analysis. We estimate the studied interval was deposited over a duration of 0.3 Myr with a depositional rate of c. 5.7 cm/kyr. Paleomagnetic and radio isotope dating data shows that the diatomaceous shale was deposited during Chron C5En, which places it at approximately 18.5 Ma during the Burdigalian stage of the Early Miocene, rather than in the Middle Miocene as previously thought. The Shanwang lagerstätte biota therefore predates the Middle Miocene Climate Optimum (MMCO) and did not form within it. The geological time scale with a high resolution of 20 kyr was set accordingly.

Effect of Ionic Liquids on the Fibril-Formation and Gel Properties of Grass Carp (Ctenopharyngodon idellus) Skin Collagen

Zhongwei Zhai,Haibo Wang,Benmei Wei,Peiwen Yu,Chengzhi Xu,Lang He,Juntao Zhang,Yuling Xu 한국고분자학회 2018 Macromolecular Research Vol.26 No.7

Self-assembled environment of collagen is one of the important factors for improving and regulating the properties of collagen-based biomaterials. This study aimed to investigate the effect of ionic liquids (ILs) on the fibril-formation and gel properties of grass carp (Ctenopharyngodon idellus) skin collagen. Fibrillogenic kinetics analysis showed that the collagen self-assembly can be suppressed by the introduction of ILs, and the inhibitory effect is influenced by concentration and types of ILs. Scanning electron microscopy test indicated that the assembled collagen fibrils in the presence of ILs had bigger diameters than that in the conventional buffer. Differential scanning calorimetry analysis revealed that the thermal stability of collagen fibrils can be significantly increased when self-assembly is performed in the presence of ILs. Moreover, the introduction of ILs enhanced the mechanical strength of collagen gels. Finding from this work provides a new idea for improving the performance of fish-sourced collagen biomaterials.

A Tower-Shaped Three-Dimensional Piezoelectric Energy Harvester for Low-Level and Low-Frequency Vibration

Xiaoxiang Wei,Haibo Zhao,Junjie Yu,Yiming Zhong,Yanlin Liao,Shiwei Shi,Peihong Wang 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.5

The multiple forms of vibration exist in an ambient environment diffusely and already become a considerable object for energy harvesting. However, how to effectively extract low-level, low-frequency, and multi-directional vibration from the ambient environment is becoming a key issue in the field of energy harvesting. To solve this issue, a tower-shaped piezoelectric vibration energy harvester (TS-PVEH) is reported. Finite element simulation indicates that TS-PVEH works in two fundamental modes, i.e., its in-plane and out-of-plane vibration modes. Meanwhile, simulation results show that the natural frequency of TS-PVEH is 3.39 Hz, 3.40 Hz, and 11.50 Hz, respectively; and the experiments also verified that. By virtue of the tower structure of TS-PVEH, the device is pretty sensitive to three-dimensional vibration. At a low level of acceleration 1 m/s 2 , the maximum load power of TS-PVEH is 65.8 μW in out-of-plane mode and 17.2 μW in in-plane mode, respectively. Furthermore, the effects of the PVDF connection mode on the output performance of TS-PVEH were studied in detail, and comparative experimental results show that a reasonable connection of PVDF can improve energy harvesting efficiency. The proposed TS-PVEH is expected to be used to scavenge energy from multi-dimensional, low-level, and low-frequency vibrations that present in an ambient environment.

Influence of raw material grain composition on the properties of fused silica ceramics

Qingtao Wang,Sen Li,Huaqin Yu,Fengzhi Li,Huijun Xu,Haibo Qiao,Juncheng Liu,Qingyang Du 한양대학교 세라믹연구소 2017 Journal of Ceramic Processing Research Vol.18 No.8

Fused silica ceramics were prepared by slip casting method with various particle sizes (d50 ≈ 2.31 μm, 19.79 μm, and 71.46 μm)from three types of fused silica powder. The influence of raw material grain composition on the viscosity of slurry, bulk density,porosity, water absorption, and flexural strength of the fused silica ceramics was investigated. The slurry viscosity wasmeasured by an XND-1 viscometer. The bulk density, porosity, and water absorption of the sintered samples were obtainedby the Archimedes method. The flexural strength was measured by a three-point bending test. The phase composition andmicrostructure of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Theresults show that when the grain composition was 5 : 3 : 2, slurry viscosity was 150.79 mPa·s with solid content of 75%, thefused silica ceramic particles were packed most tightly and demonstrate bulk density of 2.02 g/cm3, porosity of 6.99%, waterabsorption of 3.47%, and flexural strength of 51.27 MPa.

Motion planning and simulation verification of a hydraulic hexapod robot based on reducing energy/flow consumption

Zongquan Deng,Yiqun Liu,Liang Ding,Haibo Gao,Haitao Yu,Zhen Liu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.10

Minimizing the energy and flow consumption is significant to realize the locomotion of a hydraulically actuated hexapod robot formobile field applications. This paper proposes a low energy cost foot trajectory planning method to realize a constant velocity of the bodyand optimize the power and flow consumption of a hexapod robot. A dephased gait generating method is also proposed to decrease theflow demand. A simulation platform for hexapod robots was developed using C++ and based on the vortex physics engine. Power andflow consumption models were derived to verify the proposed methods. The simulation platform was used to verify the effectiveness ofthe proposed methods at optimizing the power and flow consumption.