A Simple and Fast Action Recognition Method Based on AdaBoost Algorithm

Xiaofei Ji,Lu Zhou,Ningli Qin,Yibo Li 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.8

A novel feature representation method based on AdaBoost algorithm is put forward for action recognition in this paper. The method can not only adequately describe action in complex scenarios, but also select the most discriminative sample subset from a large amount of raw features of training data. So it can realize a double result, that is, reduce the recognition computational complexity and achieve a good recognition accuracy. The pyramid histogram of oriented gradient feature (PHOG) descriptor is utilized to represent raw feature data. In order to select most discriminative samples subset, AdaBoost algorithm is used to extract the raw feature data. The nearest neighbor classifier algorithm is utilized to test the proposed method on the UCF Sports database. Experiment results show that the method not only achieve the better recognition rate but also greatly improve the speed of recognition.

Comparison of Biological Characteristics of Human Umbilical Cord Wharton’s Jelly-Derived Mesenchymal Stem Cells from Extremely Preterm and Term Infants

Huang Peng,Qin Xiaofei,Fan Chuiqin,Wang Manna,Chen Fuyi,Liao Maochuan,Zhong Huifeng,Wang Hongwu,Ma Lian 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.5

BACKGROUND: Despite the progress in perinatal-neonatal medicine, complications of extremely preterm infants continue to constitute the major adverse outcomes in neonatal intensive care unit. Human umbilical cord Wharton’s Jellyderived mesenchymal stem cells (HUMSCs) may offer new hope for the treatment of intractable neonatal disorders. This study will explore the functional differences of HUMSCs between extremely preterm and term infants. METHODS: UMSCs from 5 extremely preterm infants(weeks of gestation: 22?5 w,24?4 w,25?3 w,26 w,28 w) and 2 term infants(39 w,39?2 w) were isolated, and mesenchymal markers, pluripotent genes, proliferation rate were analyzed. HUVECs were injured by treated with LPS and repaired by co-cultured with HUMSCs of different gestational ages. RESULTS: All HUMSCs showed fibroblast-like adherence to plastic and positively expressed surface marker of CD105,CD73 and CD90, but did not expressed CD45,CD34,CD14,CD79a and HLA-DR; HUMSCs in extremely preterm exhibited significant increase in proliferation as evidenced by CCK8, pluripotency markers OCT-4 tested by RT-PCR also showed increase. Above all, in LPS induced co-cultured inflame systerm, HUMSCs in extremely preterm were more capable to promote wound healing and tube formation in HUVEC cultures, they promoted TGFb1 expression and inhibited IL6 expression. CONCLUSIONS: Our results suggest that HUMSCs from extremely preterm infants may be more suitable as candidates in cell therapy for the preterm infants.

Iterative coupling of precise integration FEM and TD-BEM for elastodynamic analysis

Lei, Weidong,Liu, Chun,Qin, Xiaofei,Chen, Rui Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.4

The iterative decomposition coupling formulation of the precise integration finite element method (FEM) and the time domain boundary element method (TD-BEM) is presented for elstodynamic problems. In the formulation, the FEM node and the BEM node are not required to be coincident on the common interface between FEM and BEM sub-domains, therefore, the FEM and BEM are independently discretized. The force and displacement converting matrices are used to transfer data between FEM and BEM nodes on the common interface between the FEM and BEM sub-domains, to renew the nodal variables in the process of the iterations for the un-coincident FEM node and BEM node. The iterative coupling formulation for elastodynamics in current paper is of high modeling accuracy, due to the semi-analytical solution incorporated in the precise integration finite element method. The decomposition coupling formulation for elastodynamics is verified by examples of a cantilever bar under a Heaviside-type force and a harmonic load.

공압 쿠션 실린더의 충격압 흡수를 위한 스프링형 니들밸브의 동특성에 관한 연구

이재구(J. G. Lee),Qin Xiaofei(X. F. Qin),이준(J. Lee),이재천(J. C. Lee),신현명(H. M. Shin) 유공압건설기계학회 2005 드라이브·컨트롤 Vol.2 No.1

Selection and evaluation of reference genes for quantitative real‐time PCR analysis in lac insect (Kerria lacca)

Wang Weiwei,Ling Xiaofei,Bashir Nawaz Haider,Lu Qin,Zhang Jinwen,Li Tichu,Chen Hang 한국곤충학회 2022 Entomological Research Vol.52 No.2

The screening and identification of suitable reference genes are key steps in experiments involving the quantitative real-time polymerase chain reaction. However, the reference genes of Kerria lacca, a lac insect with considerable economic significance, have not been investigated. In this study, we used five statistical algorithms (ΔCt, geNorm, NormFinder, BestKeeper, and RefFinder) to evaluate the stability of eight candidate reference genes (18S rRNA, 28S rRNA, β-ACT, EF1-α, RPL10, RPL13, RPS11,andRPS15) in different developmental stages and tissues of K. lacca and under dsRNA treatment. Our results showed that the most stable reference genes were 28S rRNA and RPS11 for the developmental stages, RPL13 and RPS11 for different tissues, and β-ACT and EF1-α for dsRNA treatments. Although the target genes FA S and 17β-HSD showed consistent expression profiles (alone or in combination) when normalized to the expression levels of the stable genes, those changed when the least stable reference gene (18S rRNA) was used. These results highlight that suitable reference genes should be chosen according to the specific experimental conditions used. The reliability and stability of different reference genes can provide a firm foundation for gene expression analysis in lac insects.

Preservation of allograft bone using a glycerol solution: a compilation of original preclinical research

Brian Samsell,Davorka Softic,Xiaofei Qin,Julie McLean,Payal Sohoni,Katrina Gonzales,Mark A. Moore 한국생체재료학회 2019 생체재료학회지 Vol.23 No.1

Background: Bone allografts are used in many orthopedic procedures to provide structural stability as well as an osteoconductive matrix for bone ingrowth and fusion. Traditionally, bone allografts have been preserved by either freezing or freeze-drying. Each of these preservation methods has some disadvantages: Frozen grafts require special shipping and storage conditions, and freeze-drying requires special lyophilization equipment and procedures that may impact biomechanical integrity. This report describes an alternate type of preservation using glycerol, which allows storage of fully-hydrated tissues at ambient temperature avoiding the potential complications from freeze-drying. Methods: In the in vitro three-point bend test, cortical bone was processed and frozen, freeze-dried, or treated with glycerol-based preservation (GBP). Load was applied to each graft at a rate of 2.71mm/min. The flexural strain, flexural strength, and flexural modulus were then calculated. In the in vitro axial compression test, iliac crest wedges, fibular segments, and Cloward dowels were processed and either freeze-dried or GBP treated. The compressive strength of the grafts were tested at time zero and after real time aging of 1, 4, and 5 years. In the in vivo rat calvarial defect assessment, freeze-dried, frozen, and GBP bone implants were compared after being implanted into a critical sized defect. Samples underwent histological and biomechanical evaluation. Results: Bone grafts subjected to GBP were found to be at least biomechanically equivalent to frozen bone while also being significantly less brittle than freeze-dried bone. GBP-preserved bone demonstrated significantly greater compressive strength than freeze-dried at multiple time points. Preclinical research performed in calvaric defect models found that GBP-preserved bone had similar osteoconductivity and biocompatibility to frozen and freeze-dried samples. Conclusion: Preclinical research demonstrated that glycerol–preservation of bone yields a material that maintains biomechanical strength while eliminating the need for extensive rehydration or thaw periods if used clinically. Additionally, in vivo evidence suggests no negative impact of glycerol-preservation on the ability of bone grafts to successfully participate in new bone formation and fusion.

Iterative coupling of precise integration FEM and TD-BEM for elastodynamic analysis

Weidong Lei,Chun Liu,Xiaofei Qin,Rui Chen 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.67 No.4

The iterative decomposition coupling formulation of the precise integration finite element method (FEM) and the time domain boundary element method (TD-BEM) is presented for elstodynamic problems. In the formulation, the FEM node and the BEM node are not required to be coincident on the common interface between FEM and BEM sub-domains, therefore, the FEM and BEM are independently discretized. The force and displacement converting matrices are used to transfer data between FEM and BEMnodes on the common interface between the FEM and BEM sub-domains, to renew the nodal variables in the process of the iterations for the un-coincident FEM node and BEM node. The iterative coupling formulation for elastodynamics in current paper is of high modeling accuracy, due to the semi-analytical solution incorporated in the precise integration finite element method. The decomposition coupling formulation for elastodynamics is verified by examples of a cantilever bar under a Heaviside-type force and a harmonic load.

Metagenomic analysis suggests unique gut‐microbiota composition and GH family constitution of Macrotermes annandalei

Cui Yongzhong,Wang Weiwei,Lu Qin,Wu Hai‐Xia,Ling Xiaofei,Liu Juan,Zhang Jinwen,Chen Hang 한국곤충학회 2022 Entomological Research Vol.52 No.3

Energy supply is a major concern of human survival and development, and that concern demands new sources of renewable clean energy. Cellulose, as a renewable energy material is affected by low activity and high cost of cellulose. Studies of cellulose degrading bacterial microbiota in insect intestine have revealed that these potential microbes can be used as a rich resource of cellulose degrading strains. Here, the present study involves metagenomic sequencing of intestinal microbes of Macrotermes annandalei by Illumina PE150 and a total of 401,190 scaftigs were obtained. Open Reading frame (ORF) species annotation showed that the largest proportion of them belong to the phylum of Bacteroides, followed by Protobacteia, Firmicutes and Mucoromycota. Mapping to the CAZy database indicates that 4,539 genes encoding of glycoside hydrolase belongs to 109 distinct CAZy families. The results provide a theoretical basis for exploring new candidate bacteria for efficient cellulose degradation to obtain high cellulose resource yield.