Observer-based Actuator Fault Detection and Robust Tolerant Control for Vehicle Platoons

Xiaomin Liu,Maode Yan,Panpan Yang,Jiacheng Song 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4

This paper investigates the actuator fault detection and tolerant control problem for vehicle platoons with partial loss of effectiveness and bias faults. Considering the inherent coupling between the control input and the nonlinear term in the actuator, a decoupled observer based fault detection algorithm with time-varying threshold is developed to decide whether the actuator fault occurs in the platoon. Then, by employing radial basis function neural networks (RBF NNs) and backstepping control method, an adaptive robust fault-tolerant control (FTC) scheme is proposed, which is proved to be capable of achieving the safety, stability and tracking performance of vehicle platoons in the presence of actuator fault. Simulation studies illustrate the effectiveness of the proposed method.

Horizontal dynamic modeling and vibration characteristic analysis for nonlinear coupling systems of high-speed elevators and guide rails

Danlong Song,Peng Zhang,Yuanhao Wang,Chunhua Du,Xiaomin Lu,Kai Liu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.2

To study the horizontal vibration characteristics of high-speed elevators, a 6-DOF horizontal dynamic model of the nonlinear coupling system of guide rails, guide shoes, and elevator cabin was established. Four kinds of guide rail excitation models, namely, sinusoidal, triangular, stepped, and pulsed excitation, were established through an error and contact analysis of guide rails and rollers. The factors that influenced the horizontal vibration response, such as excitation models, stiffness of guide shoes, and cabin parameters, were analyzed by solving the vibration acceleration of the coupling system. Vibration acceleration was measured through experiments to verify the theoretical results. The vibration acceleration of the no-load elevator under stepped excitation was the largest. Reducing the stiffness of the guide shoes and straightness error of guide rails, reasonably arranging the spacing between the guide shoes at the top and bottom of the cabin, and increasing the cabin weight were beneficial to reducing the horizontal vibration response of the elevator cabin.

Outcomes of Anti-CD19 CAR-T Treatment of Pediatric B-ALL with Bone Marrow and Extramedullary Relapse

Xinyu Wan,Xiaomin Yang,Fan Yang,Tianyi Wang,Lixia Ding,Lili Song,Yan Miao,Xiang Wang,Yani Ma,Chengjuan Luo,Jingyan Tang,Longjun Gu,Jing Chen,Yanjing Tang,Jun Lu,Benshang Li 대한암학회 2022 Cancer Research and Treatment Vol.54 No.3

PurposeAnti-CD19 chimeric antigen receptor T-cell immunotherapy (19CAR-T) has achieved impressive clinical results in adult and pediatric relapsed/refractory (r/r) B-lineage acute lymphoblastic leukemia (B-ALL). However, the application and effect of CAR-T therapy in B-ALL patients with extramedullary relapse are rarely issued even disqualified in some clinical trials. Here, we examined the efficacy of 19CAR-T in patients with both bone marrow and extramedullary involvement.Materials and MethodsCAR-T cells were generated by transfection of primary human T lymphocytes with a lentiviral vector expressing anti-CD19 single chain antibody fragments (scFvs) with the cytoplasmic domains of 4-1BB and CD3ζ, and used to infuse patients diagnosed as having r/r B-ALL with extramedullary origination. Clinical responses were evaluated by the use of bone marrow aspiration, imaging, and flow cytometry. ResultsEight patients received 19CAR-T infusion and all attained complete remission (CR). Only one patient was bridged to hematopoietic stem cell transplantation (HSCT). Although three patients relapsed after infusion, they received 19/22CAR-T infusion sequentially and attained a second remission. To date, five patients are in continuous CR and all eight patients are still alive. The mean follow-up time was 21.9 months, while the 24-month estimated event-free survival is 51.4%. Conclusion19CAR-T therapy can lead to clinical remission for extramedullary relapsed pediatric B-ALL patients. However, the problem of CD19+ relapses after CAR-T remained to be solved. For patients relapsing after CAR-T, a second CAR-T therapy creates another opportunity for remission for subsequent HSCT.

Enhanced Online Strip Crown Prediction Model Based on KCGAN-ELM for Imbalanced Dataset

Xiaoke Hu,Xiaomin Zhou,Hongfei Liu,Hechuan Song,Shuaikun Wang,Hongjia Zhang 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.25 No.8

The strip crown directly affects the quality of strip steel. To enhance online crown control and product quality, an accurate and efficient strip crown prediction model is crucial. The accuracy of the prediction model is determined by the algorithm and dataset used in the modeling process. The accuracy can be enhanced by increasing algorithm complexity but it does not meet the requirements of online applications. Besides, the datasets collected for strip crown prediction are usually imbalanced, which impacts the modeling accuracy. In this paper, an enhanced strip crown prediction model based on KCGAN-ELM is established. A new hybrid algorithm KCGAN is proposed to deal with the imbalanced datasets. ELM is used to establish the strip crown prediction model. To meet the requirements of online applications, incremental learning is introduced, enabling the prediction model to update in real-time based on new production data. On this basis, an update strategy is devised to ensure the prediction model can maintain qualified prediction ability during the updating process. The experiment results indicate that the model trained with the dataset processed by KCGAN demonstrates a significantly enhanced prediction accuracy, achieving an RMSE of 2.86 μm and an R2 value of 0.97. The proposed update strategy enhances the stability of prediction capability during the model updating process.

Use of Ecosystem Flux Data and a Simulation Model to Examine Seasonal Drought Effects on a Subtropical Coniferous Forest

Na Mi,Guirui Yu,Wuefa Wen,Xiaomin Sun,Shusen Wang,Leiming Zhang,Xia Song 한국기상학회 2009 Asia-Pacific Journal of Atmospheric Sciences Vol.45 No.2

The Qianyanzhou (QYZ) forest site is located in the mid-subtropical region under typical subtropical continentalmonsoon climate. Despite its plentiful water and heat resources, changes in their seasonal distributions result in frequent occurrences of seasonal drought, influencing both the structure and function of forest ecosystems. In order to examine the effects of drought stress on energy and water fluxes and the related physiological processes, we used tower flux measurements from 2003 and 2004 from the QYZ site and the ecosystemmodel EALCO (Ecological Assimilation of Land and Climate Observations). The model explained almost 90%of the variance in the daily LE for both years; whereas 71%and 55% of the variance in H for 2003 and 2004, respectively. Simulations suggested that, during the 2003 summer drought, about 80% of water extraction by roots occurred below 0.45 m, and canopy stomatal conductance decreased in response to soil dryness at a threshold r (relative water content) of 0.5 m. The response of canopy stomatal conductance appeared to be linked to the soil water exposed to themajority of the roots, even if substantialwater was being extracted fromgreater depth. The decrease of canopy stomatal conductance made the ratio of transpiration to ET relatively constant along the years with only a small difference. The different extent of the seasonal drought resulted in different water fluxes for the two years with more distinct influence on evaporation than on transpiration.

Modeling and Virtual Screening of Antisense Peptides Targeting the Divergent Region of Tumor-Associated MT1-MMP Protein

Bowen Tan,Yijie Zhou,Zhilei Song,Yinxuan Peng,Fang Wu,Yue Kang,Xiaomin Liu,Li Zeng,Tingting Huang,Zongying Liu,Lili Xiong,Zhiyun Guo,Jian Cui,Canquan Mao 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.9

Membrane type-1 matrix metalloproteinase (MT1-MMP; also known as MMP14) is a key enzyme involved in tumor invasion and metastasis, and is a potential target for drug discovery for cancer therapy. However, till now there is no MT1-MMP- or MMP-based anticancer drugs in the market mainly because of the high conservation of the MMP family and also because there is no elucidated crystal structure for the mature MT1-MMP. The modeling of the three-dimensional structure of mature MT1-MMP and the finding of MT1-MMP targeted peptides by virtual screening are highly desired. In this study, the three-dimensional structure of mature MT1-MMP is constructed by homology and de novo modeling and later rationalized and optimized by molecular dynamics simulations. An antisense peptide library was constructed against the divergent sense peptide DEGTEEET in the specific region of MT1-MMP, which was found by multiple alignment of the whole MMP family. The antisense peptide library was virtually screened against the constructed three-dimensional model of MT1-MMP. The top 20 novel peptides were further studied, which were found well docked with MT1-MMP at the region of DEGTEEET, again confirming their specific binding to MT1-MMP. Preliminary study of one of the top-ranked peptide SFLLSPFV showed that it could inhibit the viabilities of MG63 and MDA-MB-231 tumor cells. We thus not only successfully modeled the three-dimensional structure of mature MT1-MMP but also provided a new way for the finding of peptide candidates targeting MT1-MMP based on antisense peptide library.

The clinical outcomes of fresh versus frozen embryos transfer in women ≥40 years with poor ovarian response

Conghui Liu,Yu Li,Hong Jiang,Yingchun Liu,Xiaomin Song 대한산부인과학회 2021 Obstetrics & Gynecology Science Vol.64 No.3

ObjectiveTo compare the clinical outcomes of fresh embryo transfers (ETs) and frozen-thawed embryo transfers (FETs) after afreeze-all cycle in women ≥40 years old with poor ovarian response (POR). MethodsWe performed a single-center, retrospective, case-control study of patients who underwent in vitro fertilizationbetween January 2014 and June 2019. We included a total of 192 patients aged 40 years or older from whom 3 orfewer oocytes had been retrieved and who were receiving cleavage-stage ET in this study. Of these patients, 101 and91 patients underwent fresh ET and FET, respectively. The primary outcome was the live birth rate (LBR) after thefirst ET. Logistic regression analysis was used to compare the IVF outcomes and neonatal characteristics between thefresh ET and FET groups, adjusting for maternal age, body mass index, luteinizing hormone, and the number of goodquality embryos transferred. ResultsThe mean maternal ages and number of oocytes retrieved (43.2 years and 2.3 in both groups, P=0.902 and P=0.927,respectively) were similar in the fresh ET and FET groups. No significant difference was observed between the LBRsof the fresh ET and FET groups (adjusted odds ratio, 1.28; 95% confidence interval, 0.29–5.70). The clinical pregnancyand miscarriage rates, and neonatal characteristics (birth weights and premature infant rates) were similar betweenthe 2 groups. ConclusionsFET after the freeze-all strategy had no beneficial impact on the clinical outcomes of women ≥40 years with POR.

The role of CTNNB1 and LEF1 in feather follicles development of Anser cygnoides and Anser anser

Yue Sun,Yuxuan Zhou,Petunia Msuthwana,Jing Liu,Chang Liu,Cornelius Tlotliso Sello,Yupu Song,Ziqiang Feng,Shengyi Li,Wei Yang,Yunpeng Xu,Xiaomin Yan,Chuanghang Li,Yujian Sui,Jingtao Hu,Yongfeng Sun 한국유전학회 2020 Genes & Genomics Vol.42 No.7

Background Wingless-types/beta-catenin (Wnt/β-catenin) signaling pathway is one of the most extensively studied transcriptional cascades involved in various types of organogenesis including embryonic and postnatal development. Downy feather quantity is primarily affected by follicular development and gene regulations. Objective This research was aimed to investigate the role of catenin beta-1(CTNNB1) and lymphoid enhancerbinding factor-1 (LEF1) on feather follicles development at different developmental stages. Methods Fluorescence quantitative PCR, Western-blot and immunohistochemical methods were used in Anser cygnoides and Anser anser embryos (E12, E13 E18, and E28) and after birth gosling stages (G18, G48, G88) for gene expression analysis. Results CTNNB1 and LEF1 genes were expressed in Anser cygnoides and Anser anser at different embryonic and after-birth gosling developmental stages and the expression levels were significantly different in different stages (p < 0.05). The mRNA expression of CTNNB1 and LEF1 genes reached the highest level at D88 in Anser cygnoides, while the highest expression levels were at D18 and D88 in Anser anser, and the expression levels of CTNNB1 genes at D88 in all embryonic stages were significantly lower than after-birth stages. CTNNB1 and LEF1 protein expression were the highest at E12 and E28 for Anser cygnoides feather follicles development. While at a similar stage for Anser anser, the expression of CTNNB1 and LEF1 protein was the highest at D48 and D18. Protein expression at embryonic stages was in the epidermis (E) and the hair basal plate (P), the expression site for after-birth stages was in the dermal papilla (DP). Conclusion Our study illustrated that CTNNB1 and LEF1 has an impact on Anser cygnoides and Anser anser feather follicles growth and development.