A Study on the Production of Realistic Expression Animation Based on Training Mode

Zhang Gao-he(장가오허),Kim Ki-hong(김기홍),Hou Zheng-dong(후정동) 한국콘텐츠학회 2022 한국콘텐츠학회 종합학술대회 논문집 Vol.2022 No.7

Low-stiffness spring element constraint boundary condition method for machining deformation simulation

He-chuan Song,Yi-du Zhang,Qiong Wu,Han-jun Gao 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.10

The 3-2-1 constraint principle has been widely applied as the boundary conditions for the finite element method (FEM) to simulate machining deformation of aerospace structure components. However, this principle is inconsistent with the actual contact surface between workpieces and worktables because it provides only three constraint points. These points have rarely been studied in terms of positions and distances. In addition, the applicability of the principle is limited for the workpiece with geometric centers difficult to find or centers without nodes. Therefore, this study proposed a new boundary condition method, low-stiffness spring element constraint method (SECM), drawing on FEM theories and related mechanic theories. With the method proposed this study established the FE model of machining deformation, and then compared the simulation results with both the analytical results and the experimental results of milling and deformation measurements. Good agreement is found between the three results. Finally, this study examined the effect of the three constraint points on simulation of the 3-2-1 principle in terms of point positions and distances. A comparison between SECM and the 3-2-1 principle revealed that SECM is closer to the actual working conditions and more reliable with wider application, which suggests that SECM can replace the 3-2-1 principle as the boundary conditions for the workpiece.

Effective length of counterpoise wire under lightning current

He, Jinliang,Gao, Yanqing,Zeng, Rong,Zou, Jun,Liang, Xidong,Zhang, Bo,Lee, Jaebok,Chang, S. IEEE 2005 IEEE transactions on power delivery Vol.20 No.2

In a high soil resistivity area, counterpoise wires are applied to decrease the grounding resistance of tower grounding devices. If the conductor of counterpoise wire is very long, although the power frequency grounding resistance of the tower grounding device is decreased, the lightning protection performance of the transmission line is still not good. The influences of the length of grounding electrodes on the lightning transient characteristic were analyzed. The dynamic and nonlinear effect of soil ionization around the grounding electrode was considered in the analysis model of transient characteristics for the grounding electrodes under lightning impulse. The counterpoise wire has an effective length when lightning passes through it. When the length of a grounding electrode exceeds the effective length, the grounding conductor will not be utilized effectively. The simulating experiments were performed to analyze influences of the length of the counterpoise wire on the impulse characteristics. The formulae to calculate the impulse effective lengths of counterpoise wires were proposed. The model proposed in the paper has been validated by comparing the numerical results with experimental tests.

Chinese Word Sense Disambiguation Based on Beam Search

Zhang Chun-Xiang,He Shan,Gao Xue-Yao,Lu Zhi-Mao 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.11

Research on word sense disambiguation (WSD) is of great importance in natural language processing. In this paper, a new method based on beam search algorithm for Chinese WSD is proposed. By mining potential knowledge between phrase and semantic category in a sentence, this approach can construct its semantic network. It searches an optimal semantic category sequence from a Chinese sentence's semantic network with beam search algorithm, so that correct meanings of ambiguous words can be found from the optimal sequence. Experiments show that a better WSD performance is gotten.

Effect of compressible membrane's nonlinear stress-strain behavior on spiral case structure

Zhang, Qi-Ling,Wu, He-Gao Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.1

With an active structural involvement in spiral case structure (SCS) that is always the design and research focus of hydroelectric power plant (HPP), the compressible membrane sandwiched between steel spiral case and surrounding reinforced concrete was often assumed to be linear elastic material in conventional design analysis of SCS. Unfortunately considerable previous studies have proved that the foam material serving as membrane exhibits essentially nonlinear mechanical behavior. In order to clarify the effect of membrane (foam) material's nonlinear stress-strain behavior on SCS, this work performed a case study on SCS with a compressible membrane using the ABAQUS code after a sound calibration of the employed constitutive model describing foam material. In view of the successful capture of fitted stress-strain curve of test by the FEM program, we recommend an application and dissemination of the simulation technique employed in this work for membrane material description to structural designers of SCS. Even more important, the case study argues that taking into account the nonlinear stress-strain response of membrane material in loading process is definitely essential. However, we hold it unnecessary to consider the membrane material's hysteresis and additionally, employment of nonlinear elastic model for membrane material description is adequate to the structural design of SCS. Understanding and accepting these concepts will help to analyze and predict the structural performance of SCS more accurately in design effort.

Efficacy of an adhesive nanopesticide on insect pests of rice in field trials

Gao Yunhao,Li Donglin,Li Dongyang,Xu Pengfei,Mao Kaikai,Zhang Yunhua,Qin Xueying,Tang Tao,Wan Hu,Li Jianhong,Guo Mingcheng,He Shun 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

Nanopesticides with antiwashing capacity on leaves are the most promising new approaches for sustainable pest management and have been fully evaluated in the laboratory. However, few studies have tested these nanopesticides on pests, and their efficacy under field conditions has not been investigated. In this study, an adhesive hollow mesoporous silica hybrid with well-defined spherical shape and good monodispersity was used as a nanocarrier of cyantraniliprole (CNAP) to fabricate an adhesive nanopesticide (CNAP-HMS-PDAAM). The control efficacy of CNAP-HMS-PDAAM was tested under field conditions. The results indicated that the efficacy of four doses of CNAP-HMS-PDAAM (30.0–69.0 g a.i./ha) against Cnaphalocrocis medinalis (Guénee) 3, 7, and 14 days after spraying did not significantly differ from that of Benevia (34.5 g a.i./ha). Twenty-eight days after spraying, the efficacy of all four doses of CNAP-HMS-PDAAM was significantly better than that of Benevia. Additionally, the efficacy of CNAP-HMS-PDAAM at doses of 34.5, 39.0 and 69.0 g a.i./ha against Chilo suppressalis (Walker) were significantly higher than that of Benevia (34.5 g a.i./ha). Thus, CNAP-HMS-PDAAM showed long-term control efficacies against C. medinalis (Guénee) and C. suppressalis (Walker), mainly due to its strong adhesive property on rice leaves and its sustained release properties. In addition, the nanocarriers showed good biocompatibility and had no obvious influence on the growth of rice.

Power Control Strategies for Single-Phase Voltage-Controlled Inverters with an Enhanced PLL

Gao, Jiayuan,Zhao, Jinbin,He, Chaojie,Zhang, Shuaitao,Li, Fen The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1

For maintaining a reliable and secure power system, this paper describes the design and implement of a single-phase grid-connected inverter with an enhanced phase-locked loop (PLL) and excellent power control performance. For designing the enhanced PLL and power regulator, a full-bridge voltage-controlled inverter (VCI) is investigated. When the grid frequency deviates from its reference values, the output frequency of the VCI is unstable with an oscillation of 2 doubling harmonics. The reason for this oscillation is analyzed mathematically. This oscillation leads to an injection of harmonics into the grid and even causes an output active power oscillation of the VCI. For eliminating the oscillation caused by a PLL, an oscillation compensation method is proposed. With the proposed method, the VCI maintains the original PLL control characteristics and improves the PLL robustness under grid frequency deviations. On the basis of the above analysis, a power regulator with the primary frequency and voltage modulation characteristics is analyzed and designed. Meanwhile, a small-signal model of the power loops is established to determine the control parameters. The VCI can accurately output target power and has primary frequency and voltage modulation characteristics that can provide active and reactive power compensation to the grid. Finally, simulation and experimental results are given to verify the idea.

Indirect-direct band gap transition through electric tuning in bilayer MoS2.

Zhang, Z Y,Si, M S,Wang, Y H,Gao, X P,Sung, Dongchul,Hong, Suklyun,He, Junjie American Institute of Physics 2014 The Journal of chemical physics Vol.140 No.17

<P>We investigate the electronic properties of bilayer MoS2 exposed to an external electric field by using first-principles calculations. It is found that a larger interlayer distance, referring to that by standard density functional theory (DFT) with respect to that by DFT with empirical dispersion corrections, makes indirect-direct band gap transition possible by electric control. We show that external electric field effectively manipulates the valence band contrast between the K- and γ-valleys by forming built-in electric dipole fields, which realizes an indirect-direct transition before a semiconductor-metal transition happens. Our results provide a novel efficient access to tune the electronic properties of two-dimensional layered materials.</P>

Phosphodiesterase 4D contributes to angiotensin II-induced abdominal aortic aneurysm through smooth muscle cell apoptosis

Gao Ran,Guo Wenjun,Fan Tianfei,Pang Junling,Hou Yangfeng,Feng Xiaohang,Li Bolun,Ge Weipeng,Fan Tianhui,Zhang Tiantian,Lu Jiakai,Jing He,Jin Mu,Yan Chen,Wang Jing 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Abdominal aortic aneurysm (AAA) is a permanent expansion of the abdominal aorta that has a high mortality but limited treatment options. Phosphodiesterase (PDE) 4 family members are cAMP-specific hydrolyzing enzymes and have four isoforms (PDE4A-PDE4D). Several pan-PDE4 inhibitors are used clinically. However, the regulation and function of PDE4 in AAA remain largely unknown. Herein, we showed that PDE4D expression is upregulated in human and angiotensin II-induced mouse AAA tissues using RT-PCR, western blotting, and immunohistochemical staining. Furthermore, smooth muscle cell (SMC)-specific Pde4d knockout mice showed significantly reduced vascular destabilization and AAA development in an experimental AAA model. The PDE4 inhibitor rolipram also suppressed vascular pathogenesis and AAA formation in mice. In addition, PDE4D deficiency inhibited caspase 3 cleavage and SMC apoptosis in vivo and in vitro, as shown by bulk RNA-seq, western blotting, flow cytometry and TUNEL staining. Mechanistic studies revealed that PDE4D promotes apoptosis by suppressing the activation of cAMP-activated protein kinase A (PKA) instead of the exchange protein directly activated by cAMP (Epac). Additionally, the phosphorylation of BCL2-antagonist of cell death (Bad) was reversed by PDE4D siRNA in vitro, which indicates that PDE4D regulates SMC apoptosis via the cAMP-PKA-pBad axis. Overall, these findings indicate that PDE4D upregulation in SMCs plays a causative role in AAA development and suggest that pharmacological inhibition of PDE4 may represent a potential therapeutic strategy.

Model Predictive Torque Control of Surface Mounted Permanent Magnet Synchronous Motor Drives with Voltage Cost Functions

Zhang, Xiaoguang,Hou, Benshuai,He, Yikang,Gao, Dawei The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

In this paper, a model predictive torque control (MPTC) without the use of a weighting factor for surface mounted permanent-magnet synchronous machine (SPMSM) drive systems is presented. Firstly, the desired voltage vector is predicted in real time according to the principles of deadbeat torque and flux control. Then the sector of this desired voltage vector is determined. The complete enumeration for testing all of the feasible voltage vectors is avoided by testing only the candidate vectors contained in the sector. This means that only two voltage vectors in the sector need to be tested for selecting the optimal voltage vector in each control period. Thus, the calculation time can be reduced when compared with the conventional enumeration method. On the other hand, a novel cost function that only includes the dq-axis voltage errors between the desired voltage and candidate voltage is designed to eliminate the weighting factor used in the conventional MPTC. Thus, the control complexity caused by the tuning of the weighting factor is effectively decreased when compared with the conventional MPTC. Simulation and experimental investigation have been carried out to verify the proposed method.