Suboptimal Relational Tree Configuration and Robust Control Based on the Leader-follower Model for Self-organizing Systems Without GPS Support

Zhi-gang Xiong,Ya-Song Luo,Zhong Liu,Zhi-kun Liu 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.4

This paper surveys the formation acquisition and maintenance of multi-agent systems, while the communication graph is obtained without human designations. Given that all agents move along unpredictable paths during formation acquisition, the systems adopt the leader-follower model. For better expression of the graph construction, a relational tree is introduced to describe the follower-leader pairs. Then, a distributed method is proposed for suboptimal relational tree configuration. By utilizing particle swarm optimization (PSO), the search for follower-leader pairs is converted to permutation optimization. Based on principal component analysis (PCA), the entire group is divided into several small groups, and the optimization can be implemented in each group, thus releasing the computation burden. To acquire the formation defined by the suboptimal relational tree, a second nonlinear controller subject to the loss of GPS information is established. The controller takes the reference in the local velocity frame as inputs, and proportional and differential components are introduced to provide a soft control. In addition, adaptive parameters are designed for robust control. By tuning the parameters autonomously, self-organized systems can work well in various scenarios even without manual adjustment of parameters. Mathematical and numerical analyses are conducted to prove the feasibility of the proposed strategy.

Email Spam Filtering Based on the MNMF Algorithm

Zun-xiong Liu,Shan-shan Tian,Zhi-qiang Huang,Jiang-wei Liu 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.1

Content-based email spam filtering is a challenging problem in which emails are often represented as high-dimensional data. This paper proposes an approach to email spam filtering based on max-margin semi-NMF (MNMF). MNMF combines the ideas of semi-NMF and max-margin and performs dimension reduction and classification simultaneously. In MNMF, we employ the same approach as Semi-NMF to update the coefficient matrix (while the other parameters are fixed) instead of quadratic programming. Simulation experiments were performed on two public Chinese email corpuses. The results show that MNMF is much faster and performs much better than support vector machine (SVM) classifiers that use features extracted by principal component analysis or linear discriminant analysis, and the MNMF method also outperforms SVM classification schemes in combination with feature extractions based on NMF and Semi-NMF

Recurrence Season Impacts the Survival of Epithelial Ovarian Cancer Patients

Liu, Xiao-Hui,Man, Ya-Nan,Wu, Xiong-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Background: Several studies indicated that the diagnosis season affects the prognosis of some cancers, such as examples in the prostate, colon and breast. This retrospective study aimed to investigate whether the diagnosis and recurrent season impacts the prognosis of epithelial ovarian cancer patients. Methods: From January 2005 to August 2010, 161 epithelial ovarian cancer patients were analyzed and followed up until August 2013. Kaplan-Meier survival curves and the log-rank test were used to make the survival analysis. Multivariate analysis was conducted to identify independent prognostic factors. Results: The prognostic factors of overall survival in epithelial ovarian cancer patients included age, clinical stage, pathological type, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles. Moreover, clinical stage, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles also impacted the progression-free survival of epithelial ovarian cancer patients. The diagnosis season did not have a significantly relationship with the survival of operable epithelial ovarian cancer patients. Median overall survival of patients with recurrent month from April to November was 47 months, which was longer (P < 0.001) than that of patients with recurrence month from December to March (19 months). Median progression-free survival of patients with recurrence month from April to November and December to March was 20 and 8 months, respectively (P < 0.001). Conclusion: The recurrence season impacts the survival of epithelial ovarian cancer patients. However, the diagnosed season does not appear to exert a significant influence.

Actinorugispora endophytica gen. nov., sp. nov., an actinomycete isolated from Daucus carota.

Liu, Min-Jiao,Zhu, Wen-Yong,Li, Jie,Zhao, Guo-Zhen,Xiong, Zhi,Park, Dong-Jin,Hozzein, Wael N,Kim, Chang-Jin,Li, Wen-Jun Society for General Microbiology 2015 International journal of systematic and evolutiona Vol.65 No.8

<P>An actinomycete strain, designated YIM 690008T, was isolated from Daucus carota collected from South Korea and its taxonomic position was investigated by using a polyphasic approach. The strain grew well on most media tested and no diffusible pigment was produced. The aerial mycelium formed wrinkled single spores and short spore chains, some of which were branched. The whole-cell hydrolysates contained meso-diaminopimelic acid, glucose, mannose, ribose, galactose and rhamnose. The predominant menaquinones were MK-10(H4), MK-10(H6), MK-10(H8) and MK-10(H2). The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannosides, some unknown phospholipids, glycolipids and polar lipids. The major fatty acids were i-C16?:?0, ai-C17?:?0 and C18?:?1ω9c. The DNA G+C content of the genomic DNA was 63.1?mol%. Phylogenetic analysis indicated that the isolate belongs to the family Nocardiopsaceae. However, based on phenotypic, chemotaxonomic and genotypic data, it was concluded that strain YIM 690008T represents a novel genus and novel species of the family Nocardiopsaceae, for which the name Actinorugispora endophytica gen. nov., sp. nov. (type strain YIM 690008T?=?DSM 46770T?=?JCM 30099T?=?KCTC 29480T) is proposed.</P>

Inhibition of cancer cell growth and migration by dihydroxynaphthyl aryl ketones

Wei Xiong,Yun-Feng Li,Shan Liu,Ting Chen,Hong-Tao Zhang,Zhi-Bin Yang,Ying-Ying Ding,De-Pei Gao,Guan-Shun Wang,Jian Dong,Jian Dong 대한독성 유전단백체 학회 2016 Molecular & cellular toxicology Vol.12 No.4

Dihydroxynaphthyl aryl ketones 1-5 exhibit activity as tubulin polymerization inhibitors by targeting the colchicine binding site of microtubules making them potential anticancer drugs. Therefore, analogues 1-5 have been evaluated for their cytotoxic activity against the cancer cell lines DU-145 (prostate), T24 (bladder) and MCF-7 (breast). notable differences in biological activity were observed for compounds 1-5, most likely related to the nature of the aryl substituent bonded to the carbonyl group. among the tested compounds, only compound 5 showed selectivity for cancer cells over healthy, non-transformed cells. T24 cancer cells treated with compound 5 presented a concentration-dependent decrease in cell proliferation and a loss of migration ability. The cytotoxicity of compounds 1-5 on the selected cell-based assays is discussed in terms of it lipophilicity and polarizability parameters.

Experimental Study on Shear Transfer Performance of Uncracked Monolithic Steel Fiber Concrete

Qing Zhi,Jingang Xiong,Wenjie Yang,Sha Liu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.12

Shear transfer performance at interface of steel fiber reinforced concrete (SFRC) is of great importance that many factors influence the shear transfer performance of SFRC such as concrete strength and aggregate interlock, reinforcement dowel action and steel fiber. Many studies have focused on part of the factors. The shear transfer performance of uncracked monolithic SFRC is studied in this paper by considering the combined effects of cohesion, clamping stress, confined stress, reinforcement, and steel fiber. Thus, this study presents a series of direct shear tests by Z-type push-off specimens. The direct shear strength, failure mode and failure process of plain SFRC and reinforced SFRC are studied, and their shear stress-slip and shear stress-crack width responses of the tested specimens are obtained. Test results showed that reinforcement and steel fibers can improve the ductile behavior and shear strength of the shear interface simultaneously. And shear stress-slip and –crack curves of the test specimens with those combined effects are strongly nonlinear. Finally, based on the existing shear strength calculation model and the test results of this paper, a shear transfer calculation formula of SFRC interface is proposed and verified according to the Mohr Coulomb failure criteria.

Dynamics of Microbial Community Structure, Function and Assembly Mechanism with Increasing Stand Age of Slash Pine (Pinus elliottii) Plantations in Houtian Sandy Area, South China

Zhang Xiaoyang,Xiong Si-Yi,Wu Xiukun,Zeng Bei-Bei,Mo Yang-Mei,Deng Zhi-Cheng,Wei Qi,Gao Yang,Cui Licao,Liu Jianping,Long Haozhi 한국미생물학회 2023 The journal of microbiology Vol.61 No.11

Establishing slash pine plantations is the primary method for restoring sandification land in the Houtian area of South China. However, the microbial variation pattern with increasing stand age remains unclear. In this study, we investigated microbial community structure and function in bare sandy land and four stand age gradients, exploring ecological processes that determine their assembly. We did not observe a significant increase in the absolute abundance of bacteria or fungi with stand age. Bacterial communities were dominated by Chloroflexi, Actinobacteria, Proteobacteria, and Acidobacteria; the relative abundance of Chloroflexi significantly declined while Proteobacteria and Acidobacteria significantly increased with stand age. Fungal communities showed succession at the genus level, with Pisolithus most abundant in soils of younger stands (1- and 6-year-old). Turnover of fungal communities was primarily driven by stochastic processes; both deterministic and stochastic processes influenced the assembly of bacterial communities, with the relative importance of stochastic processes gradually increasing with stand age. Bacterial and fungal communities showed the strongest correlation with the diameter at breast height, followed by soil available phosphorus and water content. Notably, there was a significant increase in the relative abundance of functional groups involved in nitrogen fixation and uptake as stand age increased. Overall, this study highlights the important effects of slash pine stand age on microbial communities in sandy lands and suggests attention to the nitrogen and phosphorus requirements of slash pine plantations in the later stages of sandy management.

Functional Conservation of an AGAMOUS Orthologous Gene Controlling Reproductive Organ Development in the Gymnosperm Species Taxus chinensis var. mairei

Yongjun Fei,Zhi-Xiong Liu,Hai-Yan Xiong,Lai-Yun Li 한국식물학회 2018 Journal of Plant Biology Vol.61 No.1

Arabidopsis AGAMOUS (AG) has roles in specifying reproductive organ (stamens and carpels) identity, floral meristem determinacy, and repression of A-function. To investigate possible roles of AG orthologous genes in gymnosperm species and evolution of C function, we isolated and identified AG orthologous gene TcAG from Taxus chinensis var. mairei (family Taxaceae, order Coniferales), a member of the last divergant lineage from higher Conifer that sisters to Gnetales. Sequence alignment and phylogenetic analysis grouped TcAG into the gymnosperm AG lineage. TcAG was expressed in both developing male and female cones, but there was no expression in juvenile leaves. Ectopic expression of TcAG in an Arabidopsis ag mutant produced flowers with the third whorl petaloid stamen and fourth whorl normal carpel, but failed to convert first whorl sepals into carpeloid organs and second whorl petals into stamenoid organs. A 35S::TcAG transgenic Arabidopsis ag mutant had very early flowering, and produced a misshapen inflorescence with a shortened floral axis. Our results suggest that establishment of the complete C-function occurred gradually during AG lineage evolution even in gymnosperms.

Membrane surface charge and morphological and mechanical properties of young and old erythrocytes

Xing-Yao Chen,Yao-Xiong Huang,Wen-jing Liu,Zhi-jian Yuan 한국물리학회 2007 Current Applied Physics Vol.7 No.s1

ditions were studied as a function of cell age. The young and old cells were separated from fresh rabbit blood by using Percoll densitygradients. A novel multi-dimensional microscope was employed to perform real-time, non-invasivein situmeasurements on the mem-brane bending elastic modulus and the cell shape and size. A phase-analysis micro-electrophoresis laser scattering technique was usedto measure the surface charge density. The results show that the membrane Zeta potential of red blood cells is reduced when they become.

Rapid preparation and characterization of chitosan nanoparticles for oligonucleotide

Mu-hua Cheng,Yao-xiong Huang,Han-jian Zhou,Zhi Liu,Jian-fang Li 한국물리학회 2010 Current Applied Physics Vol.10 No.3

Chitosan is regarded as one of the potential candidates as a gene carrier. However, the poor solubility of chitosan is the major limiting factor in its utilization as a gene carrier. The purpose of this study was to simplify the method of preparing the nanoparticles of chitosan linked with antisense oligonucleotide (asON). The main step was preparing the derivatives of chitosan phosphate (CSP) in order to easily dissolve in aqueous solution. The nanoparticles were formed using a simple mixed method for CSP and asON, and the nanoparticle’s forming condition was optimized so that the nanoparticle’s characterization could be examined. Results showed that it was simple to make the nanoparticles under the optimal condition of 2:1 M proportion of CSP and asON. The size of the nanoparticles was 102.6 ± 12.0 nm, its zeta potential was 1.45 ± 1.75, and the encapsulated ratio of the chitosan crosslinked the asON was 87.6 ± 3.5%. The infrared spectra and electron microscope displayed that chitosan may combine with the asON to form equirotal nanoparticles. In conclusion, it was simple and feasible to form chitosan nanoparticles for asON using the CSP, and the CSP can efficiently encapsulate asON.