Adaptive Fuzzy Sliding Mode Control Based on Pi-sigma Fuzzy Neutral Network for Hydraulic Hybrid Control System Using New Hydraulic Transformer

Wei Shen,Jiehao Wang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.7

Control issue is the key for applying hydraulic hybrid system, especially for common pressure rail (CPR)system which has the huge potential to enhance efficiency. In the paper, the mathematical model of hydrauliccylinder speed control system using new hydraulic transformer is established. Then an adaptive fuzzy sliding modecontroller based on Pi-sigma fuzzy neutral network is designed to solve the problem of parameter uncertainty andnonlinearity without establishing the precise model. Furthermore, compared to PID and conventional adaptivefuzzy system, the controller proposed can achieve good control performance and strong robustness in the presenceof time-varying uncertainty.

Fatigue Life Evaluation of Welded Joints Considering the Local Multiaxial Stress/Strain States and Numerically Determined Residual Stresses/Strains

Wei Shen,Renjun Yan,Xiaoxing Wang,Enqian Liu,Lin Xu 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.1

This paper puts forward a kind of calculation method of estimating fatigue crack initiation life by considering welding residual stresses as initial stresses. The numerical method could be used to quantitatively analyze the influence of residual stresses on the cumulative fatigue damage. In order to gain the distribution of weld-induced residual stresses, the FE analyses as well as measurements were carried out. Based on critical plane approach, analysis of damage parameters was performed considering both welding residual stress and biaxial loads. Subsequently, validity of the proposed numerical method is verified by analyzing fatigue test results for several typical welded joints. It is concluded that the result of the present method is closer to the experimental value than that obtained with empirical formula method in the estimation of fatigue crack initiation life of welded structures.

SRSF7 is a promising prognostic biomarker in hepatocellular carcinoma and is associated with immune infiltration

Shen Wei,Yuan Lebin,Cheng Fei,Wu Zhao,Li Xiaodong 한국유전학회 2024 Genes & Genomics Vol.46 No.1

Background Previous studies indicate that the splicing process, regulated by the cellular machinery of tumors (spliceosome), undergoes alterations, leading to oncogenic splicing events associated with the progression of tumors towards aggressiveness. However, the role of serine/arginine-rich splicing factor 7 (SRSF7) in hepatocellular carcinoma (HCC) and the tumor microenvironment (TME) remains unclear. Methods This study was aimed to explore the role and clinical significance of SRSF7 in HCC. By conducting functional analysis and gene set enrichment analysis, it was discovered that SRSF7 contributes to multiple pathways associated with immune response and tumor advancement. Further experiments verified that silencing of SRSF7 obviously inhibits progression of HCC. Results Aberrant expression of SRSF7, which were referred as an independent prognostic risk factor, effectively predicts the prognosis of patients with HCC. Functional and gene enrichment analyses revealed that SRSF7 is linked with multiple immune and tumor progression-related pathways, including the B cell receptor signaling pathway, positive regulation of leukocyte and immunoglobulin receptor binding cell activation, nuclear division, membrane invagination, cell cycle, as well as mTOR signaling pathway. Furthermore, increased SRSF7 expression was associated with tumor-infiltrating inflammatory cells (CD4+, monocytes/macrophages, CD8 + and endothelial). Additionally, multiple immune checkpoint genes were markedly positively related to SRSF7. The efficiency of SRSF7 in predicting immunomodulator and chemokine responses were also assessed in microenvironment. Moreover, in vitro analyses demonstrated that knockdown of SRSF7 suppressed the malignant evolution of HCC possibly by deactivating the PI3K/AKT/mTOR signaling. Conclusion The role of SRSF7 in the tumor microenvironment has been successfully assessed. It may be a valid bio-index for predicting the HCC prognosis, thereby guiding individualized immunotherapy for cancer. Background Previous studies indicate that the splicing process, regulated by the cellular machinery of tumors (spliceosome), undergoes alterations, leading to oncogenic splicing events associated with the progression of tumors towards aggressiveness. However, the role of serine/arginine-rich splicing factor 7 (SRSF7) in hepatocellular carcinoma (HCC) and the tumor microenvironment (TME) remains unclear. Methods This study was aimed to explore the role and clinical significance of SRSF7 in HCC. By conducting functional analysis and gene set enrichment analysis, it was discovered that SRSF7 contributes to multiple pathways associated with immune response and tumor advancement. Further experiments verified that silencing of SRSF7 obviously inhibits progression of HCC. Results Aberrant expression of SRSF7, which were referred as an independent prognostic risk factor, effectively predicts the prognosis of patients with HCC. Functional and gene enrichment analyses revealed that SRSF7 is linked with multiple immune and tumor progression-related pathways, including the B cell receptor signaling pathway, positive regulation of leukocyte and immunoglobulin receptor binding cell activation, nuclear division, membrane invagination, cell cycle, as well as mTOR signaling pathway. Furthermore, increased SRSF7 expression was associated with tumor-infiltrating inflammatory cells (CD4+, monocytes/macrophages, CD8 + and endothelial). Additionally, multiple immune checkpoint genes were markedly positively related to SRSF7. The efficiency of SRSF7 in predicting immunomodulator and chemokine responses were also assessed in microenvironment. Moreover, in vitro analyses demonstrated that knockdown of SRSF7 suppressed the malignant evolution of HCC possibly by deactivating the PI3K/AKT/mTOR signaling. Conclusion The role of SRSF7 in the tumor microenvironment has been successfully assessed. It may be a valid bio-index for predicting the HCC prognosis, thereby guiding individualized immunotherapy for cancer.

Prognostic Significance of Tumor Mutation Burden among Patients with Non-small Cell Lung Cancer Who Received Platinum-based Adjuvant Chemotherapy: An Exploratory Study

Wei-Xi Shen,Guang-Hua Li,Yu-Jia Li,Peng-Fei Zhang,Jia-Xing Yu,Di Shang,Qiu-Shi Wang 대한암예방학회 2023 Journal of cancer prevention Vol.28 No.4

This study aimed to investigate the prognostic significance of tumor mutation burden (TMB) among patients with non-small cell lung cancer (NSCLC) who received platinum-based adjuvant chemotherapy. Tumor tissue specimens after surgical resection were collected for DNA extraction. Somatic mutation detection and TMB analysis were conducted using next-generation sequencing (NGS). Recurrence status of the patients was assessed in the hospital during the adjuvant chemotherapy period, and long-term survival data of patients were obtained by telephone follow-up. Univariate analysis between TMB status and prognosis was carried out by survival analysis. A retrospective review of 78 patients with non-squamous NSCLC who received platinum-based adjuvant chemotherapy showed a median disease-free survival of 3.6 years and median overall survival (OS) of 5.3 years. NGS analysis exhibited that the most common mutated somatic genes among the 78 patients were tumor suppressor protein p53 (TP53), epidermal growth factor receptor, low-density lipoprotein receptor related protein 1B, DNA methyltransferase 3 alpha and FAT atypical cadherin 3, and their prevalence was 56.4%, 48.7%, 37.2%, 30.7%, and 25.6%, respectively. TMB status was divided into TMB-L (≤ 4.5/Mb) and TMB-H (> 4.5/Mb) based on the median TMB threshold. Relevance of TMB to prognosis suggested that the median OS of patients with TMB-L was significantly longer than that of patients with TMB-H (NR vs. 4.6, P = 0.014). Higher TMB status conferred a worse implication on OS among patients with non-squamous NSCLC who received platinum-based adjuvant chemotherapy.

Working Memory and Second Language Learning: A Review of the Past Twenty Years’ Research in China

Wei Shen,박혜숙 범태평양 응용언어학회 2020 범태평양응용언어학회지 Vol.24 No.1

This paper systematically reviews the studies of working memory in second language learning in China over the past 20 years. A total of 140 studies that were published in 13 major foreign language journals during the past 20 years (2000-2019) were categorized and analyzed according to research method, educational level, and research content. For research method, two phases could be identified: from 2000 to 2006, more attention focused on introducing theory and reviewing literature regarding the association between working memory and second language learning; and from 2007 to 2019, there is a growing body of quantitative and qualitative research. For educational level of the 75 empirical studies, the majority were targeted at adult learners, whose L2 proficiency was assumed to be at or beyond intermediate level. For the research content, they were classified into three dimensions: L2 understanding, L2 output, and the integration of L2 understanding and output. These three dimensions were sub-divided into a total of seven aspects: vocabulary, grammar, listening, reading, speaking, writing, and interpretation. Considerable advances have been made in the knowledge of working memory and second language learning. Nevertheless, more research is needed to develop a deeper understanding of the interrelationships between working memory and different domains of second language learning.

High-precision Position Tracking Control of Electro-hydraulic Servo Systems Based on an Improved Structure and Desired Compensation

Wei Shen,Xinyu Liu,Xiaoyu Su 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.11

How to improve the position tracking accuracy of electro-hydraulic servo system is a hot issue today. Full state feedback control has received widespread attention for its ability to significantly improve control performance,however, its practical application range is limited in view of the large influence of measurement noise. In terms of this issue, we propose an adaptive robust controller based on improved structure and desired compensation. Firstly,to reduce the impact of measurement noise, the actual state value is substituted by the corresponding desired value in the controller design based on model compensation and the adaptive model compensator. Then, we introducea new auxiliary variable into the controller to optimize its structure. In addition, nonlinear robust control laws are integrated in the controller to balance unstructured uncertainties. Simulation analysis shows that the proposedcontrol strategy not only achieves the asymptotic tracking when parameter perturbation exists, but also ensures a specified transient response and final tracing precision under the combined influence of structured and unstructureduncertainties. The results indicate that the control strategy has good control accuracy as well as strong robustness

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.

Blind Source Separation of Instantaneous Mixture of Delayed Sources Using High-Order Taylor Approximation

Wei Zhao,Zhi-Gang Yuan,Yue-hong Shen,Yufan Cao,Yimin Wei,Pengcheng Xu,Wei Jian 한국전자통신연구원 2015 ETRI Journal Vol.37 No.4

This paper deals with the problem of blind source separation (BSS), where observed signals are a mixture of delayed sources. In reference to a previous work, when the delay time is small such that the first-order Taylor approximation holds, delayed observations are transformed into an instantaneous mixture of original sources and their derivatives, for which an extended second-order blind identification (SOBI) approach is used to recover sources. Inspired by the results of this previous work, we propose to generalize its first-order Taylor approximation to suit higher-order approximations in the case of a large delay time based on a similar version of its extended SOBI. Compared to SOBI and its extended version for a first-order Taylor approximation, our method is more efficient in terms of separation quality when the delay time is large. Simulation results verify the performance of our approach under different time delays and signal-to-noise ratio conditions, respectively.

Using Adaptive Bandwidth Allocation Approach to Defend DDoS Attacks

Wei-Shen Lai,Chu-Hsing Lin,Jung-Chun Liu,Hsun-Chi Huang,Tsung-Che Yang 보안공학연구지원센터 2008 International Journal of Software Engineering and Vol.2 No.4

Denial of service attacks occur when the attacks are from a single host, whereas distributed denial of service attacks occur when multiple affected systems flood the bandwidth or resources of a targeted system. Although it is not possible to exempt entirely from denial of service or distributed denial of service attacks, we can limit the malicious user by controlling the traffic flow. In the paper, we propose to monitor the traffic pattern in order to alleviate distributed denial of service attacks. A bandwidth allocation policy will be adopted to assign normal users to a high priority queue and suspected attackers to a low priority queue. Simulations conducted in network simulator of our proposed priority queue-based scheme shows its effectiveness in blocking attacking traffic while maintaining constant flows for legitimate traffic.

A New Ambiguity Elimination Method for BSS Block Signals in Time Domain

Wei Zhao,Fengshan Wang,Yuehong Shen,Yuanyuan Wu,Zhigang Yuan,Pengcheng Xu,Pengcheng Xu,Yimin Wei,Wei Jian 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.11

This paper deals with the ambiguity problem of blind source separation (BSS) in the case where continuously received mixture signals are split in time and processed block by block. Due to the inherent permutation and scaling ambiguities of BSS, tying the separated components at each adjacent time blocks doesn’t recover the original source signals correctly in general. Inspired by the Permutation Method of reconstructing source signal blocks in time domain, a new ambiguity elimination approach is proposed in this paper. This method aims to concatenate the separated components in adjacent blocks by artificially setting contrast blocks for each adjacent time blocks. The core idea of this method is to utilize the associativity between components recovered from contrast blocks and corresponding adjacent blocks. Compared with Permutation Method, the main advantage of this new method consists in the fact that it is much more efficient in terms of separation quality and computational speed. Besides, a tradeoff can be adjusted between separation quality and computational speed by choosing different length of contrast blocks. Real-life experiments are performed to validate the performance of this method on the wireless communication system with two transmitting and receiving antennas.