Sliding Mode Control Design via Piecewise Smooth Lipschitz Surfaces based on Contingent Cone Criteria

Xin Huo,Kemao Ma,Kai Zheng 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.4

In order to improve flexibility of sliding mode control (SMC) for a class of nonlinear systems, a new control design method is proposed in this paper. The sliding surface is extended to be a generic Lipschitz continuous surface instead of a smooth one, with which different characteristics of sliding motion may be realized. Due to the nonsmoothness of the sliding surface, the control design problem is discussed in the framework of Filippov’s differential inclusion, by analyzing the geometric properties of the nonsmooth surface. Discontinuous control laws are presented based on new contingent cone criteria, which steer all of the trajectories of the closed-loop system to reach the piecewise smooth sliding surface in finite time.

China`s Codification of Conflicts Law: Latest Efforts

( Zheng Xin Huo ) 서울대학교 법학연구소 2010 서울대학교 法學 Vol.51 No.3

This article provides a systematic introduction to and an in-depth analysis of the draft of the "Act on Application of Laws in Civil Matters involving Foreign Elements" (the Draft) which represents the latest efforts of Chinese scholars for codification of Chinese Conflicts Law and serves as a blueprint for the National People`s Congress to enact China`s first conflicts code. Part one of the article provides an overview of the status quo of Chinese private international law from the perspective of legislation, judicial practice and theory. Part two introduces the background and major features of the Draft. Part Three provides a comprehensive exegesis of the important issues of the Draft, and puts forward corresponding suggestions. In Part four, the article concludes that the Draft is, symbolically, a major achievement made by Chinese scholars, but still requires further improvement and modification.

Novel RGO and Concave Cube Cu2O Co-modified BiVO4 Nanosheets with Enhanced Photocatalytic and Surface Adsorption Performances of Tetracycline

Xin Gao,마창창,Wei Ma,Rongru Chen,Yang Liu,Zhi Liu,Zhi Zhu,Pengwei Huo,Yongsheng Yan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.2

A novel ternary Cu2O/BiVO4/RGO photocatalyst is successfully constructed by hydrothermal and evaporation-induced method, and it exhibits superior photocatalytic performance for degradation tetracycline (TC). Meanwhile, the visible light absorption range of composite photocatalyst is effectively broadened by the formation of heterojunction with narrow band gap semiconductor Cu2O. And the separation efficiency of the photogenerated electron–hole pairs is significantly enhanced by the synergistic effect of Cu2O and RGO. More importantly, the adsorption of TC by ternary Cu2O/BiVO4/RGO possesses high adsorption capacity, which is 23.73 times higher than that of pure BiVO4. Additionally, the possible reaction mechanism is clearly revealed by radical trapping experiment, electron spin-resonance (ESR) spectroscopy. This work provides a new insight to design a photocatalyst with excellent adsorption to remove organic contaminants in water.

Primary School Students` Understanding of Equation Structure and the Meaning of Equal Sign: A Chinese Sample Study

( Xin Rong Yang ),( Yu Jia Huo ),( Yan Xiong Yan ) 한국수학교육학회 2014 수학교육연구 Vol.18 No.4

This paper reports findings from a written assessment which was designed to investigate Chinese primary school students`` understanding of the equal sign and equation structure. The investigation included a sample of 110 Grade 3, 112 Grade 4, and 110 Grade 5 students from four schools in China. Significant differences were identified among the three grades and no gender differences were found. The majority of Grades 3 and 4 students were found to view the equal sign as a place indicator meaning "write the answer here" or "do something like computation", that is, holding an operational view of the equal sign. A part of Grade 5 students were found to be able to interpret the equal sign as meaning "the same as", that is, holding a relational view of the equal sign. In addition, even though it was difficult for Grade 3 students to recognize the underlying structure in arithmetic equation, quite a number of Grades 4 and 5 students were able to recognize the underlying structure on some tasks. Findings in this study suggest that Chinese primary school students demonstrate a relational understanding of the equal sign and a strong structural sense of equations in an earlier grade. Moreover, what found in the study support the argument that students`` understanding of the equal sign is influenced by the context in which the equal sign is presented.

Biosynthesis of Novel Glucosides Geldanamycin Analogs by Enzymatic Synthesis

( Qiang Huo ),( Hong Mei Li ),( Jae Kyoung Lee ),( Jing Li ),( Tao Ma ),( Xin Yu Zhang ),( Yi Qun Dai ),( Young Soo Hong ),( Cheng Zhu Wu ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

Two new glucosides (1 and 2) of geldanamycin (GA) analogs were obtained from in vitro glycosylation by UDP-glycosyltransferase (YjiC). Based on spectroscopic (HR-ESI-MS, 1D, and 2D-NMR) analyses, the glucosides were elucidated as 4,5-dihydro-7-O-descarbamoyl-7- hydroxyl GA-7-O-β-D-glucoside (1) and ACDL3172-18-O-β-D-glucoside (2). Furthermore, the water solubility of compounds 1 and 2 was about 215.2 and 90.7 times higher respectively, than that of the substrates. Among compounds 1-4, only 3 showed weak antiproliferative activity against four human tumor cell lines: MDA-MB-231, SMMC7721, HepG2, and SW480 (IC50: 13.6, 15.1, 31.8, and 22.7 μM, respectively).

CNC tool path generation for freeform surface machining based on preferred feed direction field

Guanying Huo,Xin Jiang,Cheng Su,Zehong Lu,Yuwen Sun,Zhiming Zheng,Deyi Xue 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.5

This paper presents a novel method to generate three-axis CNC tool paths for machining freeform surfaces based on a preferred feed direction field. This research was initiated from a fluid dynamics behavior that the energy loss can be reduced when the streamlines of fluid and the small grooves on a surface are in the same directions. In this research, the fluid streamlines above the surface are defined by a collection of vectors. These vectors are regularized into a grid of vectors, and these regularized vectors are further projected onto the tangent planes of a grid of points on the surface to create the preferred feed direction field. Based on the parametric model of the surface, the vectors on the tangent planes of the surface are mapped into vectors in the parametric domain. A scalar function is constructed such that the isolines of this scalar function and the preferred feed direction vectors in the parametric domain are in the same directions. A group of isolines of the scalar function are identified and these isolines are mapped back onto the 3-D surface as the created tool paths considering the tolerance requirement. The developed method has been applied to generate the tool paths for machining surfaces of a compressor blade.

Intrapleural or Intraperitoneal Lobaplatin for Treatment of Patients with Malignant Pleural Effusion or Ascites

Huang, Xin-En,Wei, Guo-Li,Huo, Jie-Ge,Wang, Xiao-Ning,Lu, Yan-Yan,Wu, Xue-Yan,Liu, Jin,Xiang, Jin,Feng, Ji-Feng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Aims: To explore efficacy and side effects of intrapleural or intraperitoneal lobaplatin for treating patients with malignant pleural or peritoneal effusions. Methods: Patients in Jiangsu Cancer Hospital and Research Institute with cytologically confirmed solid tumors complicated with malignant pleural effusion or ascites were enrolled into this study. Lobaplatin (20-30 $mg/m^2$) was intrapleurally or intraperitoneally infused for patients with malignant pleural effusion or ascites. Results: From 2012 to 2013, intrapleural or intraperitonea lobaplatin was administered for patients with colorectal or uterus cancer who were previous treated for malignant pleural effusion or ascites. Partial response was achieved for them. Main side effects were nausea/vomiting, and bone marrow suppression. No treatment related deaths occurred. Conclusion: Intrapleural or intraperitoneal infusion of lobaplatin is a safe treatment for patients with malignant pleural effusion or ascites, and the treatment efficacy is encouraging.

Apatinib as a Third-Line Treatment for HER2-Positive Metastatic Gastric Cancer: A Multi-Center Single-Arm Cohort Study

Zhang, Xin,Huo, Haoran,Nie, Yanan,Xue, Jiadong,Yuan, Zengjiang,Zhang, Zhenyi The Korean Gastric Cancer Association 2022 Journal of gastric cancer Vol.22 No.4

Purpose: Treatment options are limited after the failure of first-and second-line treatments in patients with HER2⁺ metastatic gastric cancer (mGC). The present study aimed to explore the efficacy, safety, and prognostic factors of apatinib efficacy as a third-line therapy for patients with human epithelial growth factor receptor 2-positive (HER2⁺) mGC. Materials and Methods: A total of 59 HER2⁺ mGC patients who received apatinib as third-line therapy were retrospectively enrolled in this two-center, single-arm, cohort study; the clinical response, survival data, and adverse events were retrieved. Results: The median progression-free survival (PFS) was 5.2 months (95% confidence interval [CI], 3.9-6.5), and the median overall survival (OS) was 8.2 months (95% CI, 6.6-9.8) Furthermore, forward stepwise multivariate Cox regression analysis showed that a higher Eastern Cooperative Oncology Group performance status score and multiple metastases were independently correlated with decreased PFS and OS (both P<0.05). The main adverse events were leukopenia (45.8%), hypertension (44.1%), thrombocytopenia (39.0%), hand-foot syndrome (37.3%), and elevated transaminase (33.9%). Grade 3 adverse events mainly included hypertension (5.1%) and neutropenia (5.1%); grade 4 adverse events did not occur. Conclusions: Apatinib is efficient and well tolerated in patients with HER2⁺ mGC as a third-line treatment, suggesting that it may be a candidate of choice for these patients.

A Learning Control Strategy for Robot-assisted Bathing via Impedance Sliding Mode Technique With Non-repetitive Tasks

Yuexuan Xu,Xin Guo,Bokai Xuan,Hao Sun,Gaowei Zhang,Jian Li,Xingyu Huo,Zhifeng Gu 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

This paper investigates an impedance-based iterative learning sliding mode control scheme for robotassisted bathing, taking into consideration scenarios with unknown model parameters. Initially, the utilization ofimpedance control is not confined to merely adjusting the desired trajectory but is also instrumental in ensuringactive compliance control during the robot-assisted bathing procedure. Furthermore, an iterative learning control(ILC) is devised to estimate the iteration-invariant dynamic parameters, which are intricate and challenging to precisely ascertain in practical applications. To mitigate the effect of divergent initial conditions in ILC, a trajectoryreconstruction method is introduced, thus ensuring the convergence of tracking errors even when starting from random initial states. Moreover, an adaptive sliding mode control mechanism is proposed to counteract non-parametricexternal disturbances and the torque generated through human-machine interaction during the bathing process. Theconvergence of the double closed-loop system in both the time and iterative domains is demonstrated through theapplication of the composite energy function method. Eventually, the efficacy and superiority of the control strategyoutlined in this paper are jointly verified through co-simulation employing MATLAB and ADAMS.

Parameter Identification for a Quadrotor Helicopter Using Multivariable Extremum Seeking Algorithm

Weizhen Liu,Xin Huo,Jinkun Liu,Libin Wang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

Parameter identification for a quadrotor helicopter is challenging from a theoretical point of view. In this paper, a closed-loop multivariable extremum seeking algorithm (MESA) is proposed for a nonlinear quadrotor helicopter parameter identification with two groups of input data. The proposed scheme is universally applicable to the closed-loop identification for cross-coupling multivariable processes where the identification problem is formulated as a minimization of a cost function. As the gradients of the performance parameters are obtained by step response experiments, the whole system searches along the negative gradient of the cost function until the reference trajectory or point is derived. Since the cost function is treated as a mapping from the model parameters, then the parameters can be identified online and in a real-time manner. The procedure of the identification algorithm is presented, and its effectiveness is illustrated by numerical simulations.