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Improving Public Health Multidimensional Services through the Use of Smart Cloud Model
Li Kai,Yang Hua,Zhang Yunlong,Yang Zhehan,Zhu Yan,XinYing,Meng Qun 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.8
To better understand the practical applications of smart cloud technology in response to public services improvement, this paper researches the application results of Smart Cloud Model Based Public Health Multidimensional Services (SCMBPHMS). Different from the previous studies that focused on the details, this paper establishes a relatively macroscopic large model of SCMBPHMS, we have established a knowledge model based on artificial neural network on the model data processing to sense various users’ data acquisition habits of SCMBPHMS and let Public Health Smart Cloud Service (PHSCS) gaining the function of intelligent mining and data intelligent classification via training library. Finally, we give the example of some important features of SCMBPHMS via PHP language. In future, SCMBPHMS combined with the Residents' Health Card will greatly influence the quality of Public Healthcare Services
Li, Kai,Li, Sheng,Zhao, De-You Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.3
The visualizing energy flow and control in vibrating stiffened plates with a cutout are studied using finite element method. The vibration intensity, vibration energy and strain energy distribution of stiffened plates with cutout at different excitation frequencies are calculated respectively and visualized for the various cases. The cases of different size and boundaries conditions of cutouts are also investigated. It is found that the cutout or opening completely changes the paths and distributions of the energy flow in stiffened plate. The magnitude of energy flow is significantly larger at the edges near the cutout boundary. The position of maximum strain energy distribution is not corresponding to the position of maximum vibrational energy. Furthermore, the energy-based control using constrained damping layer (CDL) for vibration suppression is also analyzed. According to the energy distribution maps, the CDL patches are applied to the locations that have higher energy distribution at the targeted mode of vibration. The energy-based CDL treatments have produced significant attenuation of the vibration energy and strain energy. The present energy visualization technique and energy-based CDL treatments can be extended to the vibration control of vehicles structures.
Li, Kai,Dong, Zhenhua,Wang, Xiaodong,Peng, Chao,Deng, Fujin,Guerrero, Josep,Vasquez, Juan The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.1
A novel strategy based on a zero common mode voltage pulse-width modulation (ZCMV-PWM) technique and zero-sequence circulating current (ZSCC) feedback control is proposed in this study to eliminate ZSCCs between three-level neutral point clamped (NPC) voltage source inverters, with common AC and DC buses, that are operating in parallel. First, an equivalent model of ZSCC in a three-phase three-level NPC inverter paralleled system is developed. Second, on the basis of the analysis of the excitation source of ZSCCs, i.e., the difference in common mode voltages (CMVs) between paralleled inverters, the ZCMV-PWM method is presented to reduce CMVs, and a simple electric circuit is adopted to control ZSCCs and neutral point potential. Finally, simulation and experiment are conducted to illustrate effectiveness of the proposed strategy. Results show that ZSCCs between paralleled inverters can be eliminated effectively under steady and dynamic states. Moreover, the proposed strategy exhibits the advantage of not requiring carrier synchronization. It can be utilized in inverters with different types of filter.
Performance Analysis of Three-Phase Phase-Locked Loops for Distorted and Unbalanced Grids
Li, Kai,Bo, An,Zheng, Hong,Sun, Ningbo The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.1
This paper studies the performances of five typical Phase-locked Loops (PLLs) for distorted and unbalanced grid, which are the Decoupled Double Synchronous Reference Frame PLL (DDSRF-PLL), Double Second-Order Generalized Integrator PLL (DSOGI-PLL), Double Second-Order Generalized Integrator Frequency-Lock Loop (DSOGI-FLL), Double Inverse Park Transformation PLL (DIPT-PLL) and Complex Coefficient Filter based PLL (CCF-PLL). Firstly, the principles of each method are meticulously analyzed and their unified small-signal models are proposed to reveal their interior relations and design control parameters. Then the performances are compared by simulations and experiments to investigate their dynamic and steady-state performances under the conditions of a grid voltage with a negative sequence component, a voltage drop and a frequency step. Finally, the merits and drawbacks of each PLL are given. The compared results provide a guide for the application of current control, low voltage ride through (LVRT), and unintentional islanding detection.
A nested algorithm of truss topology optimization for maximum plastic shakedown loading capacity
Li Kai,Cheng Gengdong 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.2
This paper proposes a nested algorithm for truss topology optimization under plastic shakedown theory, which aims at maximizing the shakedown loading capacity. The nested algorithm consists of shakedown analysis and sensitivity-based optimization. Analytical sensitivity of shakedown load with respect to the design variables is derived in a concise form for the first time in conjunction with the adjoint variable scheme. A primal-dual shakedown algorithm is implemented for the determination of the shakedown load limit of structures and adjoint variables needed in the sensitivity analysis. The ground structure approach is applied to formulate the optimization problem for determining the optimized topology and cross-sections of the truss structure. Based on the analytical sensitivity above, the nested algorithm of truss structure topology optimization can be done efficiently by a gradient-based mathematical programming algorithm. Through independent shakedown analysis and optimization processes, the proposed approach facilitates the computation scale and efficiency for large-scale structure optimization design. Several numerical examples involving two- and three-dimensional truss illustrate the effectiveness of the proposed approach.
Likai Xia,Manchala Narasimhulu,Xin Li,심재진,이용록 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.3
This paper describes a new synthetic approach for biologically interesting geranylated acetophenones. The first total syntheses of 1-(5-geranyloxy-7-hydroxy-2,2-dimethyl-2H-chromen-8-yl)ethanone and 1-[5-geranyloxy-7-hydroxy-2- methyl-2-(4-methylpent-3-enyl)-2H-chromen-8-yl]ethanone, isolated from Melicope semecarpifolia, were carried out starting from commercially available 2,4,6-trihydroxyacetophenone.
Likai Xia,이용록 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.8
This paper describes efficient synthetic approaches for isolating biologically interesting natural pyranochalcones and their unnatural derivatives from Mallotus Philippensis. The key strategies involve ethylenediamine diacetate-catalyzed benzopyran formation reactions and base-catalyzed aldol reactions.
Likai Xia,이용록,김성홍,류원석 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.5
A novel and efficient method for the synthesis of 2,3-dihydrofurans bearing a variety of substituents on the dihydrofuran ring was achieved by the reaction of cyclic diazodicarbonyl compounds with styrene and vinyl acetate. The key strategy was AgBF_4/[Bmim]BF_4-catalyzed [3+2] cycloaddition. The synthesized dihydrofurans with an acetate group were further converted to the corresponding 3-acylfurans