Direct Adaptive Fuzzy Sliding Mode Control for Under-actuated Uncertain Systems

Shun-Feng Su,Yao-Chu Hsueh,Cio-Ping Tseng,Song-Shyong Chen,Yu-San Lin 한국지능시스템학회 2015 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.15 No.4

The development of the control algorithms for under-actuated systems is important. Decoupled sliding mode control has been successfully employed to control under-actuated systems in a decoupling manner with the use of sliding mode control. However, in such a control scheme, the system functions must be known. If there are uncertainties in those functions, the control performance may not be satisfactory. In this paper, the direct adaptive fuzzy sliding mode control is employed to control a class of under-actuated uncertain systems which can be regarded as a combination of several subsystems with one same control input. By using the hierarchical sliding control approach, a sliding control law is derived so as to make every subsystem stabilized at the same time. But, since the system considered is assumed to be uncertain, the sliding control law cannot be readily facilitated. Therefore, in the study, based on Lyapunov stable theory a fuzzy compensator is proposed to approximate the uncertain part of the sliding control law. From those simulations, it can be concluded that the proposed compensator can indeed cope with system uncertainties. Besides, it can be found that the proposed compensator also provide good robustness properties.

On Neural Fuzzy Systems

Shun-Feng Su,Jen-Wei Yeh 한국지능시스템학회 2014 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.14 No.4

Neural fuzzy system (NFS) is basically a fuzzy system that has been equipped with learning capability adapted from the learning idea used in neural networks. Due to their outstanding system modeling capability, NFS have been widely employed in various applications. In this article, we intend to discuss several ideas regarding the learning of NFS for modeling systems. The first issue discussed here is about structure learning techniques. Various ideas used in the literature are introduced and discussed. The second issue is about the use of recurrent networks in NFS to model dynamic systems. The discussion about the performance of such systems will be given. It can be found that such a delay feedback can only bring one order to the system not all possible order as claimed in the literature. Finally, the mechanisms and relative learning performance of with the use of the recursive least squares (RLS) algorithm are reported and discussed. The analyses will be on the effects of interactions among rules. Two kinds of systems are considered. They are the strict rules and generalized rules and have difference variances for membership functions. With those observations in our study, several suggestions regarding the use of the RLS algorithm in NFS are presented.

On the Prediction of Arresting Efficiency of Integral Buckle Arrestors for Deepwater Pipelines

Shun-feng Gong,Gen Li 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.4

Dedicated finite element models are developed to simulate the crossing of a pipeline integral buckle arrestor by a buckle propagating under the quasi-static, steady-state condition. In addition, broad parametric studies are conducted to identify the mechanism governing the arresting performance, which consider the geometric characteristics and material properties of the pipe and arrestor. Based upon the extensive study, the more reasonable empirical design formulas for the crossover pressure and the arresting efficiency are established by means of the partial fitting. Good agreements between the existing experimental results and the predictions demonstrate that the proposed empirical formula and the lower bound envelope line for the arresting efficiency provide a powerful design tool to estimate the arresting performance of such complex structure systems in engineering practices.

Low-dose diethylhexyl phthalate exposure does not impair the expressive patterns of epigenetics-related genes and DNA methylation of breast cancer-related genes in mouse mammary glands

Shun-Feng Cheng,Ling Li,Bo Li,Jing-Cai Liu,Fang-Nong Lai,Yong Zhao,Xi-Feng Zhang,Wei Shen,Lan Li 대한독성 유전단백체 학회 2018 Molecular & cellular toxicology Vol.14 No.2

Backgrounds: Di-(2-ethylhexyl) phthalate (DEHP), as an endocrine-disrupting chemical (EDC), is widely used in plasticizer and other productions. Ubiquitous human exposure to DEHP has been proposed to be a potential risk to public health. Developmental exposure to DEHP could alter epigenetic programming and result in adult-onset disease. Methods: In this study, we investigated whether DEHP exposure to pregnant mice affected epigenetic changes as a result of increase in breast cancer incidence. Results: Our results showed that the expression of total 143 epigenetics-related genes in mammary gland cells, have no significantly altered after short time and low-dose treated with DEHP from 0.5 days post-coitum (dpc) to 3.5 dpc of pregnant mice. DNA methylation status of some neoplastic development genes, such as EGFr, Esr1, Pgr, Fos and Rassf5 also had no obvious change. Conclusion: These finding showed no impact of DEHP on the expressive patterns of epigenetics-related genes and DNA methylation of breast cancer-related genes in pregnant mouse mammary gland cells.

Buckling response of offshore pipelines under combined tension and bending

Shun-feng Gong,Xing-yue Ni,Lin Yuan,Wei-liang Jin 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.6

Offshore pipelines have to withstand combined actions of tension and bending during deepwater installation, which can possibly lead to elliptical buckle and even catastrophic failure of whole pipeline. A 2D theoretical model initially proposed by Kyriakides and his co-workers which carried out buckling response analysis of elastic-plastic tubes under various load combinations, is further applied to investigate buckling behavior of offshore pipelines under combined tension and bending. In association with practical pipe-laying circumstances, two different types of loadings, i.e., bent over a rigid surface in the presence of tension, and bent freely in the presence of tension, are taken into account in present study. In order to verify the accuracy of the theoretical model, numerical simulations are implemented using a 3D finite element model within the framework of ABAQUS. Excellent agreement between the results validates the effectiveness of this theoretical method. Then, this theoretical model is used to study the effects of some important factors such as load type, loading path, geometric parameters and material properties etc. on buckling behavior of the pipes. Based upon parametric studies, a few significant conclusions are drawn, which offer a theoretical reference for design and installation monitoring of deepwater pipelines.

FSCB phosphorylation in mouse spermatozoa capacitation

( Shun Li Liu ),( Bing Ni ),( Xiang Wei Wang ),( Wen Qian Huo ),( Jun Zhang ),( Zhi Qiang Tian ),( Ze Min Huang ),( Yi Tian ),( Jun Tang ),( Yan Hua Zheng ),( Feng Shuo Jin ),( Yan Feng Li ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.8

It is generally accepted that spermatozoa capacitation is associated with protein kinase A-mediated tyrosine phosphorylation. In our previous study, we identified the fibrous sheath CABYR binding protein (FSCB), which was phosphorylated by PKA. However, the phosphorylation status of FSCB protein during spermatozoa capacitation should be further investigated. To this aim, in this study, we found that phosphorylation of this 270-kDa protein occurred as early as 1 min after mouse spermatozoa capacitation, which increased over time and remained stable after 60 min. Immunoprecipitation assays demonstrated that the tyrosine and Ser/Thr phosphorylation of FSCB occurred during spermatozoa capacitation. The extent of phosphorylation and was closely associated with the PKA activity and spermatozoa motility characteristics. FSCB phosphorylation could be induced by PKA agonist DB-cAMP, but was blocked by PKA antagonist H-89.Therefore, FSCB contributes to spermatozoa capacitation in a tyrosine-phosphorylated format, which may help in further elucidating the molecular mechanism of spermatozoa capacitation. [BMB reports 2011; 44(8): 541-546]

Buckling response of offshore pipelines under combined tension and bending

Gong, Shun-Feng,Ni, Xing-Yue,Yuan, Lin,Jin, Wei-Liang Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.6

Offshore pipelines have to withstand combined actions of tension and bending during deepwater installation, which can possibly lead to elliptical buckle and even catastrophic failure of whole pipeline. A 2D theoretical model initially proposed by Kyriakides and his co-workers which carried out buckling response analysis of elastic-plastic tubes under various load combinations, is further applied to investigate buckling behavior of offshore pipelines under combined tension and bending. In association with practical pipe-laying circumstances, two different types of loadings, i.e., bent over a rigid surface in the presence of tension, and bent freely in the presence of tension, are taken into account in present study. In order to verify the accuracy of the theoretical model, numerical simulations are implemented using a 3D finite element model within the framework of ABAQUS. Excellent agreement between the results validates the effectiveness of this theoretical method. Then, this theoretical model is used to study the effects of some important factors such as load type, loading path, geometric parameters and material properties etc. on buckling behavior of the pipes. Based upon parametric studies, a few significant conclusions are drawn, which offer a theoretical reference for design and installation monitoring of deepwater pipelines.

On Neural Fuzzy Systems

Su, Shun-Feng,Yeh, Jen-Wei Korean Institute of Intelligent Systems 2014 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.14 No.4

Neural fuzzy system (NFS) is basically a fuzzy system that has been equipped with learning capability adapted from the learning idea used in neural networks. Due to their outstanding system modeling capability, NFS have been widely employed in various applications. In this article, we intend to discuss several ideas regarding the learning of NFS for modeling systems. The first issue discussed here is about structure learning techniques. Various ideas used in the literature are introduced and discussed. The second issue is about the use of recurrent networks in NFS to model dynamic systems. The discussion about the performance of such systems will be given. It can be found that such a delay feedback can only bring one order to the system not all possible order as claimed in the literature. Finally, the mechanisms and relative learning performance of with the use of the recursive least squares (RLS) algorithm are reported and discussed. The analyses will be on the effects of interactions among rules. Two kinds of systems are considered. They are the strict rules and generalized rules and have difference variances for membership functions. With those observations in our study, several suggestions regarding the use of the RLS algorithm in NFS are presented.

Direct Adaptive Fuzzy Sliding Mode Control for Under-actuated Uncertain Systems

Su, Shun-Feng,Hsueh, Yao-Chu,Tseng, Cio-Ping,Chen, Song-Shyong,Lin, Yu-San Korean Institute of Intelligent Systems 2015 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.15 No.4

The development of the control algorithms for under-actuated systems is important. Decoupled sliding mode control has been successfully employed to control under-actuated systems in a decoupling manner with the use of sliding mode control. However, in such a control scheme, the system functions must be known. If there are uncertainties in those functions, the control performance may not be satisfactory.In this paper, the direct adaptive fuzzy sliding mode control is employed to control a class of under-actuated uncertain systems which can be regarded as a combination of several subsystems with one same control input. By using the hierarchical sliding control approach, a sliding control law is derived so as to make every subsystem stabilized at the same time. But, since the system considered is assumed to be uncertain, the sliding control law cannot be readily facilitated. Therefore, in the study, based on Lyapunov stable theory a fuzzy compensator is proposed to approximate the uncertain part of the sliding control law. From those simulations, it can be concluded that the proposed compensator can indeed cope with system uncertainties. Besides, it can be found that the proposed compensator also provide good robustness properties.

2022 Taiwan clinical multicenter expert consensus and recommendations for thyroid radiofrequency ablation

Wei-Che Lin,Wen-Chieh Chen,Pei-Wen Wang,Yi-Chia Chan,Yen-Hsiang Chang,Harn-Shen Chen,Szu-Tah Chen,Wei-Chih Chen,Kai-Lun Cheng,Shun-Yu Chi,Pi-Ling Chiang,Chen-Kai Chou,Feng-Fu Chou,Shun-Chen Huang,Feng 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.3

Radiofrequency ablation (RFA) is a minimally invasive management strategy that has been widely applied for benign and recurrent malignant thyroid lesions as an alternative to surgery in Taiwan. Members of academic societies for specialists in interventional radiology, endocrinology, and endocrine surgery collaborated to develop the first consensus regarding thyroid RFA in Taiwan. The modified Delphi method was used to reach a consensus. Based on a comprehensive review of recent and valuable literature and expert opinions, the recommendations included indications, pre-procedural evaluations, procedural techniques, post-procedural monitoring, efficacy, and safety, providing a comprehensive review of the application of RFA. The consensus effectively consolidates advice regarding thyroid RFA in clinical practice for local experts.