Distributed Formation Control of Quadrotor UAVs Based on Rotation Matrices without Linear Velocity Feedback

Yanjie Chen,Jiacheng Liang,Zhiqiang Miao,Yaonan Wang 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.10

This paper considers the problem of the formation control for multiple underactuated quadrotor UAVs without linear velocity measurements. The objective of this paper is expected to realize smooth formation performances for a quadrotor group. A distributed formation controller is designed directly using rotation matrices to obviate the singularities associated with the Euler-angles or the ambiguity of quaternions. A two-step procedure isadopted for the control development after transforming the dynamics of each quadrotor into a new form. At first, an intermediary control variable is introduced to achieve the formation control, where some auxiliary systems are designed in the presence of lacking linear velocity measurements. Then, based on the thrust force and reference angular velocity decoded from the intermediary control variable, the torque input of each quadrotor is proposed for angular velocity tracking. The case of formation control with a virtual leader is also investigated, where at least one quadrotor has the information of the leader. The asymptotic stability of the proposed control system is analyzed by Lyapunov-like tools, and the effectiveness of the proposed control method is verified by simulation studies. Thesimulation results show that the proposed method can guide the quadrotor group to form the desired formation smoothly without linear velocity feedback, which has great potentials for the UAV group to execute the challenging mission in hostile environments.

Chinese herbal medicines on cognitive function and activity of daily living in senior adults with Alzheimer's disease: a systematic review and meta-analysis

Yanjie Zhang,Kyoungmin Noh,송욱 한국한의학연구원 2019 Integrative Medicine Research Vol.8 No.2

Background: This systematic review was performed to investigate the effects of Chinese herbal nedicine (CHM) on cognitive function and activity of daily living (ADL) in individuals with Alzheimer's disease. Methods: Five electronic databases (Medline, Embase, Cinahl, PsycArticles, and CNKI) were searched from inception to January 2019. Randomized controlled trials (RCTs) assessing the effect of CHM on cognition and activity of daily living in adults with Alzheimer's disease were included. We pooled the effects size using the Comprehensive Meta-Analysis Software. Cochrane risk of bias tool was used to evaluate the study quality. Results: Twenty-five RCTs (1855 individuals with AD) were included in this review. Overall findings of this meta-analysis indicated that CHM improved the cognitive function (SMD = 0.66, 95% CI [0.44, 0.89], I2 = 77.9%, p < 0.001) and ADL (SMD = 0.38, 95% CI [0.25, 0.49], I2 = 35.3%, p < 0.001) compared with conventional drugs. No publication biases were observed on both cognitive function and ADL. Conclusion: CHM may have potential effects for improving cognitive function and ADL for individuals with AD compared with conventional drug therapies. However, the evidence is limited because of high risk of bias of the included trials.

How Household Roles Influence Individuals’ Travel Mode Choice under Intra-household Interactions?

Yanjie Ji,Yang Liu,Qiyang Liu,Baohong He,Yu Cao 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

The household is usually an essential element for activity-based travel decision-making of individuals. From the perspective of household context, activities are often allocated to individuals based on their household roles, thereby affecting individuals’ travel behavior. By defining the household role using spatial-temporal constraints which are associated with individual activities and household activities, this paper investigates the travel mode choice of individuals considering the effect of different household roles. The descriptive statistics of the household roles and their corresponding travel mode choice are presented using the data from Kunming, China. The statistical results show that the modal splits between females and males perform a significant difference in the same household roles. Furthermore, the travel mode choice of females and males are estimated separately using multinomial logistic regression model. The results show that those who face more space-time constraints associated with household tasks are less willing to travel by car. While with the increase of commuting constraints, household heads, especially female-heads, tend to use car to meet the travel demands of household activity. Besides, individuals’ age, education level, the number of cars and bikes in household also have a significant impact on travel mode choices of individuals.

An efficient k-continuous line drawing using the traveling salesman problem

Yanjie Zhou,Gyu M. Lee 한국경영과학회 2016 한국경영과학회 학술대회논문집 Vol.2016 No.4

Effects of Li2CO3 on the sintering behavior and piezoelectric properties of Bi2O3-excess (Bi0.5Na0.5)0.94Ba0.06TiO3 ceramics

Yanjie Zhang,Ruiqing Chu,Zhi-Jun Xu,Qian Chen,Yong Liu,Guangchao Zhang 한국물리학회 2012 Current Applied Physics Vol.12 No.1

(Bi0.5Na0.5)0.94Ba0.06TiO3 ceramics doped with Li2CO3 and Bi2O3 as sintering aids were manufactured, and their micro structural, dielectric and piezoelectric properties were investigated. All specimens could be well sintered at a low-temperature of 1080 ℃. The bulk density of the specimens doped with a small amount of Li2CO3 was enhanced. The dielectric and piezoelectric properties of ceramics were investigated with different amounts of Li2CO3 substitutions. High electrical properties of d33 ¼ 167 pC/N,kp ¼ 0.34, Pr ¼ 40 mC/cm2 and Ec ¼ 38 kV/cm were obtained from the specimen containing 0.1 mol% of Li2CO3 sintered at 1080 ℃.

Output Feedback Stabilization for a Class of Cascade Nonlinear ODEPDE Systems

Yanjie Chang,Tongjun Sun,Xianfu Zhang,Xiandong Chen 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.7

In this paper, the output feedback stabilization problem is studied for a class of cascade nonlinear ODEPDE systems. The nonlinear terms of ODE-subsystem are assumed to be bounded by a known constant multiplied by unmeasured states, and PDE-subsystem is a diffusion equation. Especially, the unstable diffusion equation is considered. Based on the low gain observer and a series of transformations, the output feedback stabilization problem is converted into designing proper gain parameters. Furthermore, the stability of the closed-loop system is analyzed by Lyapunov theorem. Finally, two numerical examples are given to demonstrate the effectiveness of the proposed control strategy.

An Examination of the Factors that Influence Drivers’ Willingness to Use the Parking Guidance Information

Yanjie Ji,Pengming Fu,P.T. Blythe,W. Guo,Wei Wang 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.7

Parking Guidance and Information (PGI) System becomes highly favorable for reducing circulating traffic and making efficient use of existing parking facilities. This paper is to examine the factors influence drivers’ willingness to use PGI. Factor analysis and the Structure Equation Model (SEM) were used to identify the latent attitudinal factors and the sensitivity of the factors was judged by Bayesian network. The heterogeneity of the factors was explored based on driver’s gender, age, driving years, education and travel frequency. The results show that drivers’ willingness to use PGI is significantly correlated to five attitudinal factors: perception of existing PGIs, difficulty in parking, confidence in the accuracy of the information, easy acquisition of information and information attributes. Male drivers, younger drivers, novice drivers and drivers who travel less frequently have lower level of willingness to use PGI.

Laproscopic Liver Resection for Hepatocellular Carcinoma: 5-Year Experience at a Single Center

( Yanjie Xu ),( Dong Hee Ryu ),( Jae-woon Choi ),( Hanlim Choi ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Laparoscopic liver resection for hepatocellular carcinoma(HCC) has become an increasingly popular operation, even in the presence of liver cirrhosis. Here we evaluate the outcomes of laparoscopic liver resection for HCC at a single center. Methods: From November 2011 to August 2016, 24 patients with HCC underwent various laparoscopic liver resection at a single institution. The operation was performed by one team of surgeons. The clinical data of these patients were retrospectively reviewed and analyzed by reviewing the medical records, radiologic images and pathologic reports. Results: The mean age of the patients was 58 years(range 41-80 years) and 22 patients were men. The types of resection were resection of one segment (7 cases), resection of two segments (9 cases), resection of three segments (2 cases) and four segments (6 cases). The mean tumor size was 3.4 cm (range 0.8-10 cm). The mean resection margin was 17.9 mm (range 1-50 mm). The median follow-up duration was 29 months (range 4-45 months). The 3-year overall survival rates were 83.3%. Conclusions: Laparoscopic liver resection for HCC is feasible, safe with good oncologic outcomes. Major liver resection is possible with improved surgeon’s skill and experience.

A Gene Cluster for the Biosynthesis of Dibenzodioxocinons in the Endophyte Pestalotiopsis microspora, a Taxol Producer

( Yanjie Liu ),( Longfei Chen ),( Qiaohong Xie ),( Xi Yu ),( Anqing Duan ),( Yamin Lin ),( Biyun Xiang ),( Xiaoran Hao ),( Wanwan Chen ),( Xudong Zhu ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.10

The fungal products dibenzodioxocinones promise a novel class of inhibitors against cholesterol ester transfer protein (CEPT). Knowledge as to their biosynthesis is scarce. In this report, we characterized four more dibenzodioxocinones, which along with a previously described member pestalotiollide B, delimit the dominant spectrum of secondary metabolites in P. microspora. Through mRNA-seq profiling in gα1Δ, a process that halts the production of the dibenzodioxocinones, a gene cluster harboring 21 genes including a polyketide synthase, designated as pks8, was defined. Disruption of genes in the cluster led to loss of the compounds, concluding the anticipated role in the biosynthesis of the chemicals. The biosynthetic route to dibenzodioxocinones was temporarily speculated. This study reveals the genetic basis underlying the biosynthesis of dibenzodioxocinone in fungi, and may facilitate the practice for yield improvement in the drug development arena.

Comparative gene expression profiling reveals key pathways and genes different in skin epidermal stem cells and corneal epithelial cells

Yanjie Guo,Weini Wu,Xiya Ma,Mingyan Shi,Xueyi Yang 한국유전학회 2019 Genes & Genomics Vol.41 No.6

Background Corneal epithelial cells (CECs) are required for corneal transparency and visual function, and corneal injuries may cause corneal blindness. Skin epidermal stem cells (SESCs), which share the same origin with CECs and have the potential of multi-directional differentiation are ideal seed cells for tissue engineered corneal construction to treat corneal blindness. Objective This study aims to investigate critical genes and pathways that may modulate the transdifferentiation from SESCs to CECs. Methods Isolated SESCs and CECs were used for gene expression analysis by microarray. GO and KEGG pathway of differently expressed genes (DEGs) were enriched using DAVID. The protein–protein interaction (PPI) network were then constructed using Cytoscape and highly interconnected module was subsequently isolated from the network by Molecular Complex Detection. Expression of the hub genes and other selected genes were then verified by qRT-PCR. Results We found 112 upregulated and 105 downregulated genes in CECs compared with SESCs. These DEGs were significantly enriched in focal adhesion, PI3K–Akt and TNF signaling pathway. Highly interconnected module of PPI network contains ten genes. Further regulatory network of these genes showed that ESR1 and SLC2A4 were hub genes. Conclusion Our study identified gene expression in SESCs and CECs and suggested that several crucial genes and pathways may play critical roles in transdifferentiation from SESCs to CECs. It may help uncover molecular mechanisms and offer a foundation for promoting tissue-engineered cornea into clinical application.