Surface Mesh Generation in Parametric Space Using a Riemannian Surface Definition

Cui Dai,Zhaoxue Wang,Liang Dong,Yiping Chen,Junfeng Qiu 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.2

In order to solve the problem of generating distortion elements in the mapping from parameter space to real space, and the boundary coincidence of the mesh generated by the software quality, an approach for parametric surface mesh generation based on Riemannian metric, combined with Delaunay triangulation and AFT is proposed. In our algorithm, the boundary curves are discretized based on the proximity and curvature of the curves in the model after derivation the correlation of curve length between parametric space and real space. Background meshes of parametric space were generated by using improved AFT, and could improve the efficient of the algorithm and control element sizing and metric values. When background mesh of parametric space were refined, to counteract mapping distortion, the traditional Delaunay incremental insertion kernel is replaced by inserting the center of triangle circumscribed ellipse, and the algorithm for locating ellipse center and judging whether nodes within ellipse. In this paper, the details of the surface mesh generated by the algorithm are introduced in detail. The algorithm proposed in this paper has the characteristics of reliable algorithm, high mesh generation efficiency and mesh quality. Finally, the reliability of the proposed algorithm is verified by an example of surface mesh generation.

Economic Low-Carbon Clean Dispatching of Power System Containing P2G Considering the Comprehensive Influence of Multi-Price Factor

Cui Dai,Ge Weichun,Zhao Wenguang,Jiang Feng,Zhang Yushi 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.1

Power-to-gas (P2G) technique realizes the two-way coupling for the integrated electricity and natural gas systems, which provides an eff ective way for wind power accommodation based on its operating characteristic. Therefore, a new economic low-carbon clean dispatching of power system containing the power to gas (P2G) considering the comprehensive infl uence of the multi-price factor is proposed. Firstly, the P2G operation and carbon trading mechanism models are established. Secondly, the goal is to minimize the sum of thermal power generation costs, gas turbine power generation costs, carbon trading cost, wind abandonment penalty cost, and P2G operating costs and taking into account the comprehensive impact of multiple price factors and the security constraints of the natural gas network and the power network. Then, the improved particle swarm optimization algorithm is used to solve the model. Finally, the rationality and eff ectiveness of the proposed model are verifi ed through the analysis of calculation examples, and it is proved that the conversion of electricity to gas can eff ectively improve the wind power absorption capacity of the grid, which provides a reference for the low-carbon dispatch operation of the integrated energy system.

Cavitation state identification of centrifugal pump based on CEEMD-DRSN

Dai Cui,Hu Siyuan,Zhang Yuhang,Chen Zeyu,Dong Liang 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4

Centrifugal pumps are a crucial part of nuclear power plants, and their dependable and safe operation is crucial to the security of the entire facility. Cavitation will cause the centrifugal pump to violently vibration with the large number of vacuoles generated, which not only affect the hydraulic performance of the centrifugal pump but also cause structural damage to the impeller, seriously affecting the operational safety of nuclear power plants. A closed cavitation test bench of a centrifugal pump is constructed, and a method for precisely identifying the cavitation state is proposed based on Complementary Ensemble Empirical Mode Decomposition (CEEMD) and Deep Residual Shrinkage Network (DRSN). First, we compared the cavitation sensitivity of pressure fluctuation, vibration, and liquid-borne noise and decomposed the liquid-borne noise by CEEMD to capture cavitation characteristics. The decomposition results are sent into a 12-layer deep residual shrinkage network (DRSN) for cavitation identification training. The results demonstrate that the liquid-borne noise signal is the most cavitation-sensitive signal, and the accuracy of CEEMD-DRSN to identify cavitation at different stages of centrifugal pumps arrives at 94.61%

Correction to: Economic Low‑Carbon Clean Dispatching of Power System Containing P2G Considering the Comprehensive Influence of Multi‑Price Factor

Cui Dai,Ge Weichun,Zhao Wenguang,Jiang Feng,Zhang Yushi 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.6

Constituents and their DPPH Scavenging Activities from the Leaves of Alnus hirsuta (Spach) Rupr.

Dai, Yinghui,Thuong, Phuong Thien,Hung, Tran Manh,Jin, Wenyi,Cui, Zheng,Bae, Ki-Hwan The Korean Society of Medicinal Crop Science 2005 한국약용작물학회지 Vol.13 No.2

Phytochemical study on the EtOAc fraction from a MeOH extract of the leaves of Alnus hirsuta Rupr. led to the isolation of nine compounds betulin (1), betulinic acid (2), hirsutanonol (3), hirsutenone (4), quercetin (5), avicularin (6), gallic acid (7), hyperin (8), and daucosterol (9). Among them, six compounds 1, 2, 57, and 9 are report from this plant for the first time. All isolated compounds were evaluated for their antioxidant activity using DPPH radical scavenging capacity and inhibition effect on mitochondrial lipid peroxidation. Six phenolic compounds 3-8 were found to have potent antioxidant activity. Of which, compounds 3, 4 and 5 showed significant free radical scavenging activity with the $IC_{50}$ values of $18.3\;{\pm}\;2.5,\;15.7\;{\pm}\;3.8\;and\;23.5\;{\pm}\;3.1\;{\mu}m$, respectively. In addition, the compounds 3-8 exhibited inhibition effect on the mitochondrial lipid peroxidation with the $IC_{50}$ values of $88.0\;{\pm}\;6.5,\;12.6\;{\pm}\;1.2,\;8.0 \;{\pm}\;1.1,\;58.5\;{\pm}\;4.3,\;173.6\;{\pm}\;15.2,\;and\;75.0\; {\pm}\; 6.7\;{\mu}m$, respectively.

Chk2 Regulates Cell Cycle Progression during Mouse Oocyte Maturation and Early Embryo Development

Dai, Xiao-Xin,Duan, Xing,Liu, Hong-Lin,Cui, Xiang-Shun,Kim, Nam-Hyung,Sun, Shao-Chen Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.2

As a tumor suppressor homologue during mitosis, Chk2 is involved in replication checkpoints, DNA repair, and cell cycle arrest, although its functions during mouse oocyte meiosis and early embryo development remain uncertain. We investigated the functions of Chk2 during mouse oocyte maturation and early embryo development. Chk2 exhibited a dynamic localization pattern; Chk2 expression was restricted to germinal vesicles at the germinal vesicle (GV) stage, was associated with centromeres at pro-metaphase I (Pro-MI), and localized to spindle poles at metaphase I (MI). Disrupting Chk2 activity resulted in cell cycle progression defects. First, inhibitor-treated oocytes were arrested at the GV stage and failed to undergo germinal vesicle breakdown (GVBD); this could be rescued after Chk2 inhibition release. Second, Chk2 inhibition after oocyte GVBD caused MI arrest. Third, the first cleavage of early embryo development was disrupted by Chk2 inhibition. Additionally, in inhibitor-treated oocytes, checkpoint protein Bub3 expression was consistently localized at centromeres at the MI stage, which indicated that the spindle assembly checkpoint (SAC) was activated. Moreover, disrupting Chk2 activity in oocytes caused severe chromosome misalignments and spindle disruption. In inhibitor-treated oocytes, centrosome protein ${\gamma}$-tubulin and Polo-like kinase 1 (Plk1) were dissociated from spindle poles. These results indicated that Chk2 regulated cell cycle progression and spindle assembly during mouse oocyte maturation and early embryo development.

Protective action of 9-hydroxypinoresinol against oxidative damage in brain of mice challenged with kainic acid

Cui, Hui Song,Sok, Dai-Eun,Min, Byung Sun,Kim, Mee Ree Pharmaceutical Society of Great Britain 2007 Journal of pharmacy and pharmacology Vol.59 No.4

A Detection Framework of Malicious Code Based on Multi-Classifiers Ensemble

Chao Dai,Jianmin Pang,Feng Yue,Pingfei Cui,Di Sun,Liang Zhu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.6

Malicious code detection is one of the important missions of malicious code analysis. Current researches on the detection of malicious code mostly focused on single classifier, whereas the single classifier is not suitable for the detection based on features of different types. We utilized multi-classifiers ensemble based on fuzzy integral to improve the accuracy of the detection framework. A framework based on the Choquet fuzzy integral was proposed to fuse the analysis results of the base classifiers with different features. And the genetic algorithm was used to obtain the fuzzy measure. Finally, the result of Choquet fuzzy integral was compared to a threshold predefined to determine the maliciousness of binary code. Experiment showed that the framework proposed in this paper could be used to determine the maliciousness of binary code more accurately.

Facile synthesis of imprinted submicroparticles blend polyvinylidene fluoride membranes at ambient temperature for selective adsorption of methyl p-hydroxybenzoate

Yanhua Cui,Minjia Meng,Dongshu Sun,Yan Liu,Jianming Pan,Xiaohui Dai,Yongsheng Yan 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.3

We developed a simple phase inversion technique to prepare molecularly imprinted membrane (MIM) at room temperature for membrane selective adsorption and separation of methyl p-hydroxybenzoate (M4HB). The prepared SMIP-MIM was characterized by SEM, FT-IR, TGA. Compared with non-imprinted membrane (NIM1-5) adsorbent, SMIP-MIM1-5 adsorbent with high specific surface area and showed higher binding capacity, faster kinetic and better selectively adsorption capacity for M4HB. The maximum isotherm adsorption capacity for M4HB of SMIPMIM4 was 3.519mg·g−1, and the experimental data was well fitted to the slips model by multiple analysis. The maximum kinetic adsorption capacity and equilibrium adsorption time for SMIP-MIM4 were 1.335mg·g−1 and 160 min, respectively. The mechanism for dynamic adsorption of M4HB onto SMIP-MIM4 was found to follow pseudo-firstorder model and pseudo-second-order model. Additionally, the permeability separation factor of SMIP-MIM4 for M4HB compared to a structural analogues methyl 2-hydroxybenzoate (M2HB) could reach 2.847. The adsorption capacity of SMIP-MIM4 for M4HB and M2HB was 0.549mg·cm−2 and 1.563mg·cm−2, respectively. The adsorption behavior of M4HB through SMIP-MIM4 followed the retarded permeation mechanism.

中国大学教育服务品质、学习成果对教育满意度的影响研究

崔文(Cui-Wen),李昌大(Lee, Chang-Dai) 한국국제회계학회 2018 국제회계연구 Vol.0 No.78

Today, the core achievements of university education are changing from how many students are exported to society and how much education services are provided to improve the university`s service quality, education service and learning outcomes. In particular, universities should shift from provider-centered thinking to consumer-centered thinking. Therefore, this study examined the relationship between educational satisfaction, learning outcome, and quality of education service in Yanbian University in China. The findings showed that factors such as university credibility, service consciousness and enthusiasm, lecture competency, educational facilities, welfare facilities and traffic conditions have positive effects on educational satisfaction. However, the moderation effect of learning outcomes on the quality of education service and the satisfaction of education was less than expected. As a result of the study, Yanbian University should be built and improve the service quality of the school by improving the satisfaction of the students, to grasp the service demand and trend of students and parents, to improve the education service system.