Function Approximation Technique Based Adaptive Control for Chaos Synchronization between Different Systems with Unknown Dynamics

Yujie Wang,Yang Bai,Mikhail Svinin 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.8

This paper presents a function approximation technique based immersion and invariance adaptive controller for chaos synchronization between nonidentical systems with unknown dynamics. In the proposed control scheme, the control system is reconstructed as the combination of a controllable linear system and a variation term from the original system. The variation term is treated as time-varying uncertainty and approximated by a group of weighted chosen basis functions. The immersion and invariance methodology is employed to design the adaptivecontrol law such that both the synchronization error and uncertainty estimation error converge to zero. Two typical chaos synchronization problems are used in numerical simulations to verify the effectiveness and superiority of the proposed controller.

Blood lipids and all-cause mortality among old people: the Chinese Longitudinal Healthy Longevity Survey 2008-2018

Wang Rongxi,Yu Xiaoyue,Wang Zhiqiang,Liu Yujie,Chen Hui,Liu Shangbin,XU CHENG,Chen Yingjie,Xia Danni,Ge Xin,Chang Ruijie,Xu Gang,Xiang Mi,Wang Ying,Shen Tian,Hu Fan,Cai Yong 한국역학회 2022 Epidemiology and Health Vol.44 No.-

OBJECTIVES: Proper blood lipid levels are essential for survival in older adults, but inconsistent relationships have been reported between blood lipids and all-cause mortality in the elderly. METHODS: This retrospective longitudinal study analyzed data from 1,067 Chinese older adults enrolled in the Chinese Longitudinal Healthy Longevity Survey collected in 2008 and followed up until death or December 31, 2018. The outcome was allcause mortality. Multivariate Cox regression analyses were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with stratification by age (60-80, 80-100, or ≥ 100 years) for further analysis. The survival probability according to lipid profile quartiles was calculated using Kaplan-Meier curves and the log-rank test. RESULTS: The participants’ mean age was 84.84 years, and 57.0% were female. In total, 578 individuals died, and 277 were lost to follow-up. The mean total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels were higher among those who died than among those who survived. Participants in the second HDL-C quartile and the highest LDL-C and triglyceride (TG) quartiles had 28% higher, 23% lower, and 49% lower risks of all-cause mortality, respectively. After further adjustment, the associations remained except for HDL-C, and additional associations were observed between all-cause mortality and the third TC and LDL-C quartiles and the second TG quartile (HR, 1.44; 95% CI, 1.01 to 2.06; HR, 0.68; 95% CI, 0.49 to 0.94; HR, 0.79; 95% CI, 0.62 to 0.99, respectively). CONCLUSIONS: Older adults should maintain an LDL-C level of 1.91-2.47 mmol/L and a TG level of no less than 1.66 mmol/L.

Bacterial Population in Intestines of Litopenaeus vannamei Fed Different Probiotics or Probiotic Supernatant

( Yujie Sha ),( Mei Liu ),( Baojie Wang ),( Keyong Jiang ),( Cancan Qi ),( Lei Wang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.10

The interactions of microbiota in the gut play an important role in promoting or maintaining the health of hosts. In this study, in order to investigate and compare the effects of dietary supplementation with Lactobacillus pentosus HC-2 (HC-2), Enterococcus faecium NRW-2, or the bacteria-free supernatant of a HC-2 culture on the bacterial composition of Litopenaeus vannamei, Illumina sequencing of the V1-V2 region of the 16S rRNA gene was used. The results showed that unique species exclusively existed in specific dietary groups, and the abundance of Actinobacteria was significantly increased in the intestinal bacterial community of shrimp fed with the bacteria-free supernatant of an HC-2 culture compared with the control. In addition, the histology of intestines of the shrimp from the four dietary groups was also described, but no obvious improvements in the intestinal histology were observed. The findings in this work will help to promote the understanding of the roles of intestinal bacteria in shrimps when fed with probiotics or probiotic supernatant.

Surface Modification of Flax Fibers with Isocyanate and Its Effects on Fiber/Epoxy Interfacial Properties

Wanru Wang,Rao Fu,Qi Deng,Xinyuan Wang,Yujie Wang,Zhao Zhang,Guijun Xian 한국섬유공학회 2020 Fibers and polymers Vol.21 No.12

Natural fiber reinforced polymer composite has been widely used in various industry fields. Natural fibertreatment can effectively improve its mechanical and durability properties, and expands its applications. In the present study,isocyanate was proposed to treat flax fibers in order to reduce the hydrophilic properties of the fibers, and to enhance thebonding of flax fiber to epoxy matrix. The isocyanate treated fabric was evaluated with fourier transform infra-red (FTIR),scanning electron microscopy (SEM) and water uptake. The effects of the fiber treatment on the mechanical properties of flaxfabric reinforced epoxy (FFRP) plates were investigated. FTIR and SEM analysis indicated that isocyanate reacts with flaxfiber, forming a thin polymer layer on the fiber surface. The water absorption test showed that isocyanate treatment decreasedthe water uptake of the flax fabric by 4-18 times compared to the control fabric. The flexural and tensile strength of FFRPwith isocyanate solution treated fabrics were enhanced more than 20 %, attributed to the improved adhesion of fiber to epoxy. Based on the above results, the treatment method of flax fiber with isocyanate is considered as an effective approach toimprove both hydrothermal ageing resistance and mechanical properties of FFRPs.

Enhanced Photoelectrochemical Water Splitting and Photocatalytic Water Oxidation of Cu2O Nanocube-Loaded BiVO4 Nanocrystal Heterostructures

Wenzhong Wang,Weiwei Zhang,Shan Meng,Lujie Jia,Miao Tan,Chenchun Hao,Yujie Liang,JUN WANG,Bin Zou 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.6

Reducing the fast recombination of photogenerated electron-hole pairsof semiconductor photocatalyst is very important to improve itsphotocatalysis. In this paper we fabricate Cu2O nanocube-decoratedBiVO4 nanocrystal (denoted as BiVO4@Cu2O nanocrystal@nanocube)heterostructure photocatalyst by coupling n-type BiVO4 with p-type Cu2O. The BiVO4@Cu2O nanocrystal@nanocube photocatalysts show superiorphotocatalytic activities in photoelectrochemical (PEC) activity andphotocatalytic water oxidation to BiVO4 photocatalysts under visible lightillumination. The BiVO4@Cu2O nanocrystal@nanocube heterostructureelectrode achieves the highest photocurrent density of ~ 10 μA cm−2 at 0 Vversus Ag/AgCl, 5 times higher than that of BiVO4 nanocrystal electrode (~ 2 μA cm−2). The light induced evolution rate of O2generation for BiVO4@Cu2O nanocrystal@nanocube heterostructures is as high as 150 μmol h−1100 mg cat−1, more than 3times higher than that (48 μmol h−1100 mg cat−1) of BiVO4 nanocrystals. The enhanced photocatalysis activities of theBiVO4@Cu2O nanocrystal@nanocube photocatalysts are attributed to the efficient separation of the photoexcited electron-holepairs caused by inner electronic field (IEF) of p-n junction. This study opens up new opportunities in designing photoactivematerials with highly enhanced performance for solar energy conversion.

Controversy on necessity of cobalt in nickel-rich cathode materials for lithium-ion batteries

Rui Wang,Lifan Wang,Yujie Fan,Woochul Yang,Chun Zhan,Liu Guicheng 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

Since the layered oxide LiCoO2 as the cathode material for commercial Li ion batteries, especially, nickelrichlayered oxide cathode materials are consolidating their status as the cathode material of choice andenabling a significant success of the passenger electric vehicle industry. Generally, cobalt in cathodes hasbeen considered necessary in enhancing electrochemical performance. However, they are still facing criticalchallenges in further commercialization. For instance, cobalt caused more severe structural degradationand capacity degradation at high potential. Additionally, it triggered O2 and heat release, whicheventually cause the interfacial instability and thermal instability of the cathode materials. Prior studiesalso confirmed that cobalt plays double-edged roles in cathodes, and questioned its necessity. Meanwhile, not only is it facing a roadblock caused by high-cost restrictions, but more importantly,50% of world mine production originates from copper-cobalt ore in the Democratic Republic of theCongo (DRC), where geopolitical instability and harsh working conditions could halt cobalt exports. Therefore, many studies have explored the possibility of cobalt-free materials. This review shed newlights on understanding the role of cobalt and reveals the perspectives of technical challenges in currentstate by the practical aspect for cobalt-free cathode materials, thereby helping to advance the futuredevelopment of next-generation low-cost and long-calendar-life batteries.

Pedestrian Detection Algorithm Combining HOG and SLBP

Aili Wang,Mingxiao Wang,Jitao Zhang,Yuji Iwahori,Bo Wang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.10

In order to solve the problem of pedestrian detection performance, the described operator was improved. In this paper, semantic local binary pattern (SLBP) and histogram of oriented gradient (HOG) are combined as new feature operator. This feature method would enrich the information and enhance the detection performance. And then histogram intersection kernel support vector machine (HIKSVM) classifier is trained by the augment feature. Because the time cost is too large by the conventional SVM. HIKSVM could make up this drawback, and significantly reduce the training time. The experiments on the INRIA pedestrian dataset show that the method obtained significant improvement in accuracy comparing to HOG descriptors.

基于语料库的英美大学招生简章比较分析

王余杰(Yujie Wang),梅勇(Yong Mei) YIXIN 출판사 2024 Journal of Humanities and Social Sciences Vol.2 No.1

招生简章是学生了解学校和进行申请或报考的重要依据。本文基于语料库,借用TagAnt、AntConc 以及WordSmith 三种软件,从类符/形符比、词汇密度、高频词、主题词、搭配、词长分析、平均句长分别对比分析了英美两国排名前十大学的招生简章,并辅以具体实例。研究发现两国大学招生简章中的高频词均以虚词为主,而主题词的选用以及搭配则有所差异。此外,在词汇使用上,美国大学招生简章更为丰富多样;而在句子使用上,英国大学招生简章长难句更多。 Enrollment prospectus is an important basis for applicants to know about the school and to apply or register. Based on the corpus, TagAnt, AntConc and WordSmith, this study uses specific examples to compare the enrollment prospectus of the top ten universities in the United Kingdom and the United States from the aspects of type/token ratio, lexical density, high frequency words, subject words, collocations, word length and average sentence length. The study finds that the high frequency words of the enrollment prospectus in two countries both focus on empty words, while the subject words and collocations are different. In terms of the word use, US universities are more diversified, while the sentences of the enrollment prospectus in UK universities are longer and more complex, which reflects the different language culture between the two countries.

The Response of Plant Photosynthesis and Stomatal Conductance to Fine Particulate Matter (PM2.5) based on Leaf Factors Analyzing

Yifan Li,Yujie Wang,Bin Wang,Yunqi Wang,Weiqing Yu 한국식물학회 2019 Journal of Plant Biology Vol.62 No.2

The effects of particles on the photosynthesis ofvegetation, which is a sink for fine particulate matter (PM2.5)deposition, are still not well understood. Here, we carried outindoor measurements to evaluate the variation dynamics ofnet photosynthetic rate and stomatal conductance of fourplant species with different leaf characteristics under differentPM2.5 levels. Then tree leaves were sampled and the grooveproportion, leaf trichome density, stomatal density and stomatalsize were quantitatively studied by scanning electron microscopy(SEM). The stomatal conductance of the 4 species had aclose positive correlation with photosynthetic rate. Netphotosynthetic rate and stomatal conductance declined overtime at elevated PM2.5, and the rate of the decline becamemore rapid with higher concentration of PM2.5. The inhibitingeffect might be caused by the closure of the stomata and thedecrease of stomatal conductance, which was proved by thereduction of the stomatal size of under the condition of PM2.5pollution. Leaf trichome and groove seemed to show aprotective role for plants from PM2.5 exposure and be responsiblefor the difference of photosynthetic rate and stomatal conductanceunder the condition of PM2.5 pollution. The higher grooveproportion and the presence of trichomes on the leaf surfacein Neolitsea aurata and Lindera kwangtungensis absorbedsome particulate matters and buffered the effect of PM2.5pollution on stomata.

A national survey on how to improve traditional Chinese medicine learning internationally: Perceptions from both teachers and students

Zhu Yu-Hang,Yan Wu,Hao Zhang,Yanfei Zhao,Yule Ren,Wei Hu,Pan Li,Huiyi Wang,Ying Wang,Boda Zhang,Yujie Wang,Hongwen Yuan,Jiping Zhang,Wenqiang Li,Yufang Zhao,Jie Zhao,Yedong Shi,Yanye Shu,Xiao Zhang,Ya 한국한의학연구원 2022 Integrative Medicine Research Vol.11 No.4

Background With the increasing popularity of traditional Chinese medicine (TCM) by the global community, how to teach basic knowledge of TCM to international students and improve the teaching quality are important issues for teachers of TCM. The present study was to analyze the perceptions from both students and teachers on how to improve TCM learning internationally. Methods A cross-sectional national survey was conducted at 23 universities/colleges across China. A structured, self-reported on-line questionnaire was administered to 34 Chinese teachers who taught TCM course in English and to 1016 international undergraduates who were enrolled in the TCM course in China between 2017 and 2021. Results Thirty-three (97.1%) teachers and 900 (88.6%) undergraduates agreed Chinese culture should be fully integrated into TCM courses. All teachers and 944 (92.9%) undergraduates thought that TCM had important significance in the clinical practice. All teachers and 995 (97.9%) undergraduates agreed that modern research of TCM is valuable. Thirty-three (97.1%) teachers and 959 (94.4%) undergraduates thought comparing traditional medicine in different countries with TCM can help the students better understand TCM. Thirty-two (94.1%) teachers and 962 (94.7%) undergraduates agreed on the use of practical teaching method with case reports. From the perceptions of the undergraduates, the top three beneficial learning styles were practice (34.3%), teacher's lectures (32.5%), case studies (10.4%). The first choice of learning mode was attending to face-to-face teaching (82.3%). The top three interesting contents were acupuncture (75.5%), Chinese herbal medicine (63.8%), and massage (55.0%). Conclusion To improve TCM learning among international undergraduates majoring in conventional medicine, integration of Chinese culture into TCM course, comparison of traditional medicine in different countries with TCM, application of the teaching method with case reports, and emphasization of clinical practice as well as modern research on TCM should be fully considered.