Resonant Parameter Design of Asymmetrical CLLC-Type DC Transformer with Robust Voltage Gain

Jingjing Huang,Xin Zhang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In the renewable energy system, the asymmetrical CLLC-type resonant DC transformer (ACLLC-type DCT) has been widely applied due to its high power-density and low-cost control. Whereas, the main circuit parameters are varying with operation power and temperature in practice, especially at the high-frequency condition. Therefore, the circuit parameters must be properly designed to achieve the robust voltage conversion gain (VCG) when adopting the open-loop scheme. To solve the above problems, this paper presents a special parameters design approach for DCT. In the proposed approach, all unknown parameters are replaced with two equivalent variables with the help of the mathematical model simplifications. Subsequently, a two-stage procedure is introduced to complete the parameters design based on the robust VCG requirement. At last, the proposed method is validated in a DCT based prototype.

An Efficient Reactive Power Regulation based DPC Method for AC/DC Converters

Huang Jingjing,Sun Yuangang,Tong Xiangqian,Li Ning 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

To eliminate the cyclical fluctuation problems of the reactive power existing in the traditional direct power control (DPC), a novel method is proposed for the threephase voltage source AC/DC converter. It employs two switching tables to select the proper switching states according to the instantaneous reactive power deviations. The design principle of the switching tables is provided to ensure the efficient reactive power regulation. Moreover, it should guarantee the steady characteristic of the converter system. The simulation model established under the MATLAB/Simulink environment and the experiment were presented to compare the characteristics obtained by the proposed strategy with that obtained by the traditional DPC strategy. The results show that the ac current obtained by the proposed strategy has the much lower total harmonic distortion rate (THD), and the fluctuation range of the reactive power has the more than two times reduction.

SINGLE STEP REAL-VALUED ITERATIVE METHOD FOR LINEAR SYSTEM OF EQUATIONS WITH COMPLEX SYMMETRIC MATRICES

JingJing Cui,ZhengGe Huang,BeiBei Li,XiaoFeng Xie 대한수학회 2023 대한수학회보 Vol.60 No.5

For solving complex symmetric positive definite linear systems, we propose a single step real-valued (SSR) iterative method, which does not involve the complex arithmetic. The upper bound on the spectral radius of the iteration matrix of the SSR method is given and its convergence properties are analyzed. In addition, the quasi-optimal parameter which minimizes the upper bound for the spectral radius of the proposed method is computed. Finally, numerical experiments are given to demonstrate the effectiveness and robustness of the propose methods.

Evaluating the efficiency of treatment comparison in crossover design by allocating subjects based on ranked auxiliary variable

Huang, Yisong,Samawi, Hani M.,Vogel, Robert,Yin, Jingjing,Gato, Worlanyo Eric,Linder, Daniel F. The Korean Statistical Society 2016 Communications for statistical applications and me Vol.23 No.6

The validity of statistical inference depends on proper randomization methods. However, even with proper randomization, we can have imbalanced with respect to important characteristics. In this paper, we introduce a method based on ranked auxiliary variables for treatment allocation in crossover designs using Latin squares models. We evaluate the improvement of the efficiency in treatment comparisons using the proposed method. Our simulation study reveals that our proposed method provides a more powerful test compared to simple randomization with the same sample size. The proposed method is illustrated by conducting an experiment to compare two different concentrations of titanium dioxide nanofiber (TDNF) on rats for the purpose of comparing weight gain.

Push-out tests on stud shear connectors with constrained structure of steel-concrete composite beams

Jingjing Qi,Zuwei Xie,Hua Cao,Zhi Huang,Weirong Lv,Weihua Shi 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.6

The stud shear connector is the main force transfer member in the steel-concrete composite member, and the mechanical behavior is very complicated in the concrete. The concrete around the stud is subjected to the pry-out local pressure concentration of the stud, which can easily produce splitting mirco-cracks. In order to solve the problem of pry-out local splitting of stud shear connector, a kind of stud shear connector with constraint measure is proposed in this paper. Through the push-out test, the interface shear behavior of the new stud shear connector between steel and concrete flange plate was studied, and the difference between the new stud shear connector and the traditional stud connector was compared. The results show that the stud shear connector with constraint measure can effectively avoid the adverse effect of local pressure splitting by relying on its own constraint measure. The shear stiffness of the interface between steel and concrete flange plates is greatly improved, which provides a theoretical basis for the design of strong connection coefficient of steel-concrete composite structures.

Subspace Aided Fault-tolerant Control for Distributed Homogeneous Systems with Symmetric Interconnection Pattern

Jingjing Gao,Xu Yang,Jian Huang,Kaixiang Peng 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.1

Stimulated by the enhancing requirements for system safety as well as process reliability in industrial processes, this paper investigates a subspace aided fault-tolerant control scheme for distributed homogeneous systems with symmetric interconnection pattern. To this end, a decomposition approach is first addressed to show how to convert and decompose the original distributed homogeneous system into a set of independent subsystems. Then, for the independent subsystems, offline subspace predictive controllers and recursive fault-tolerant subspace predictive controllers are designed respectively in a decentralized way. Finally, the controllers designed for the independent subsystems are converted back to the original distributed homogeneous system to achieve its faulttolerant control goal. The effectiveness of the proposed scheme is demonstrated by a case study on a multi-area interconnected power system.

Metabolomics reveals potential plateau adaptability by regulating inflammatory response and oxidative stress-related metabolism and energy metabolism pathways in yak

( Meizhou Huang ),( Xin Zhang ),( Wenjun Yan ),( Jingjing Liu ),( Hui Wang ) 한국축산학회 2022 한국축산학회지 Vol.64 No.1

Species are facing strong selection pressures to adapt to inhospitable high-altitude environments. Yaks are a valuable species and an iconic symbol of the Qinghai-Tibet Plateau. Extensive studies of high-altitude adaptation have been conducted, but few have focused on metabolism. In the present study, we determined the differences in the serum metabolomics between yaks and the closely related species of low-altitude yellow cattle and dairy cows. We generated high-quality metabolite profiling data for 36 samples derived from the three species, and a clear separation trend was obtained between yaks and the other animals from principal component analysis. In addition, we identified a total of 63 differentially expressed metabolites among the three species. Functional analysis revealed that differentially expressed metabolites were related to the innate immune activation, oxidative stress-related metabolism, and energy metabolism in yaks, which indicates the important roles of metabolites in high-altitude adaptation in yaks. The results provide new insights into the mechanism of adaptation or acclimatization to high-altitude environments in yaks and hypoxia-related diseases in humans.

Long-term Survivals, Toxicities and the Role of Chemotherapy in Early-Stage Nasopharyngeal Carcinoma Patients Treated with Intensity-modulated Radiation Therapy: A Retrospective Study with 15-year Follow-up

Lin Wang,Jingjing Miao,Huageng Huang,Boyu Chen,Xiao Xiao,Manyi Zhu,Yingshan Liang,Weiwei Xiao,Shaomin Huang,Yinglin Peng,Xiaowu Deng,Xing Lv,Weixiong Xia,Yanqun Xiang,Xiang Guo,Fei Han,Chong Zhao 대한암학회 2022 Cancer Research and Treatment Vol.54 No.1

Purpose This study was aimed to investigate long-term survivals and toxicities of early-stage nasopharyngeal carcinoma (NPC) in endemic area, evaluating the role of chemotherapy in stage II patients. Materials and Methods Totally 187 patients with newly diagnosed NPC and restaged American Joint Committee on Cancer/ International Union Against Cancer 8th T1-2N0-1M0 were retrospectively recruited. All received intensity-modulated radiotherapy (IMRT)±chemotherapy (CT) from 2001 to 2010. Results With 15.7-year median follow-up, 10-year locoregional recurrence-free survival, distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS) were 93.3%, 93.5%, 92.9% and 88.2%, respectively. Multivariable analyses showed cervical lymph nodes positive and pre-treatment prognostic nutritional index ≥ 52.0 could independently predict DMFS (p=0.036 and p=0.011), DSS (p=0.014 and p=0.026), and OS (p=0.002 and p < 0.001); Charlson comorbidity index < 3 points could predict DSS (p=0.011); age > 45 years (p=0.002) and pre-treatment lactate dehydrogenase ≥ 240 U/L (p < 0.001) predicted OS. No grade 4 late toxicity happened; grade 3 late toxicities included subcutaneous fibrosis (4.3%), deafness or otitis (4.8%), skin dystrophy (2.1%), and xerostomia (1.1%). No differences on survivals were shown between IMRT+CT vs. IMRT alone in stage II patients, even in T2N1M0 (p > 0.05). Unsurprising, patients in IMRT+CT had more acute gastrointestinal reaction, myelosuppression, mucositis, late ear toxicity, and cranial nerve injury (all p < 0.05) than IMRT alone group. Conclusion Superior tumor control and satisfying long-term outcomes could be achieved with IMRT in early-stage NPC with mild late toxicities. As CT would bring more toxicities, it should be carefully performed to stage II patients.

An efficient Automatic Modulation Classification method based on the Convolution Adaptive Noise Reduction network

Bai Haihai,Huang Ming,Yang Jingjing 한국통신학회 2023 ICT Express Vol.9 No.5

Due to the influence of noise in the received signal in non-cooperative communication, it is difficult for existing Automatic modulation classification methods to balance classification accuracy and model complexity. This paper proposes a novel Convolutional Adaptive Noise Reduction (CANR) network, which consists of an Adaptive Noise Reduction (ANR) module and a Convolutional Feature Extraction (CFE) module. The ANR and CFE modules denoise the combined input and capture the spatiotemporal features in the time series. Experiments on benchmark datasets show that the proposed network has the fewest training parameters and state-of-the-art recognition accuracy under the same conditions.

Breathing-based Continuous Non-intrusive User Verification Leveraging Commodity WiFi

Huan Dai,Jingjing Jiang,Jiaju Ma,He Huang,Hongbo Liu 한국통신학회 2022 Journal of communications and networks Vol.24 No.2

This paper opens up a new pathway of the utilityof breathing pattern for user verification. We demonstrate thatit is possible to capture people’s breathing pattern leveragingcommodity WiFi devices. While prior solutions for biometricsbaseduser recognition usually require dedicated devices (e.g.,video cameras or IR sensors), this paper introduces the firstgeneral, low-cost breathing-based user verification system usingcommodity WiFi devices. The proposed system is based onthe fact that the breathing pattern always keeps consistentfor the same user but distinct among different people. Ourinnovative method successfully extracts the breathing patternof different people based on channel state information of WiFisignal to facilitate user verification. The prototype study usingtwo commodity WiFi devices can differentiate people with anaverage verification accuracy over 90%, suggesting that ourbreathing-based user verification system using commerical offthe-shelf (COTS) WiFi is promising to be one of the most criticalmethods in biometrics.