Research on Grey Predictive Control of PMSM Based on Reduced-order Luenberger Observer

Huang Xianghui,Guan Penglin,Pan Hongguang,Liu Shulin,Du Guanghui,Huang Xinyi,Wang Xueyan 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

To further improve the dynamic and anti-interference performance of permanent magnet synchronous motor (PMSM) control system, a dual closed loop model predictive control (MPC) strategy combining with grey prediction and reduced-order Luenberger observer is proposed in this paper for speed and current control. To be specifi c, fi rstly, the dual closed loop MPC strategy is introduced based on the mathematical model of PMSM, that is, the model predictive controller is used for the outer loop of speed, and the deadbeat predictive controller for the inner loop of current. Secondly, considering the grey prediction method can establish grey model and whiten the system grey quantity to some extent, it is used in the PMSM control system to improve the dynamic performance. Finally, to solve the problem that the motor is easy to be aff ected by disturbances, a reduced-order Luenberger observer is designed to combine with the model predictive controller to improve the system anti-interference performance. The simulation results show that the dual MPC strategy based on grey prediction makes the system more stable and dynamic response faster, while the dual MPC strategy combining with the grey prediction and the reduced-order Luenberger observer makes the system more resistant to load disturbance.

Effect and stability of miniscrew-assisted rapid palatal expansion: A systematic review and meta-analysis

Xinyi Huang,Yu Han,Shuangyan Yang 대한치과교정학회 2022 대한치과교정학회지 Vol.52 No.5

Objective: This study aimed to systematically analyze the effect and stability of miniscrew-assisted rapid palatal expansion (MARPE) to provide a reference for the clinical treatment of patients with maxillary transverse deficiency (MTD). Methods: We searched PubMed, Science Direct, Web of Science, Embase, Cochrane Library, CNKI, and Wanfang Database for relevant studies published before February 18, 2021 and selected them according to the eligibility criteria. The Cochrane Handbook for Systematic Reviews (version 5.1.0) criteria were used for the quality assessment of randomized controlled trials, while the scoring protocol of the methodological index for non-randomized studies was used for non-randomized controlled trials. Statistical analysis was performed using the RevMan5.3 software. Results: All the included studies showed a relatively high success rate of expansion. The changes in both the intermolar and alveolar widths after MARPE were statistically significant. MARPE exhibited greater skeletal expansion effects than did conventional RPE. The midpalatal suture was opened in parallel after MARPE. A small amount of relapse was observed 1 year after expansion. MARPE caused tooth inclination and a decrease in alveolar height, but it was less significant than in conventional RPE. Conclusions: MARPE may be an effective treatment modality for patients with MTD. It causes great transverse skeletal expansion in late adolescence. In comparison to conventional RPE, MARPE has lower detrimental periodontal effects and has certain clinical advantages.

Hydrothermal Synthesis of PbTiO3 Nanocrystals with a pH-Adjusting Agent of Ammonia Solution

Xinyi Li,Zhi-Xiong Huang,Lian-Meng Zhang,Dongyun Guo 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.5

The PbTiO3nanocrystals were synthesized by a hydrothermal method, and ammonia solution was firstly used as a pH-adjustingagent. The effect of ammonia concentration on formation and morphologies of PbTiO3nanocrystals was investigated. At low ammonia concentration (0–2.2 mol/L), no perovskite PbTiO3phase was formed. When the ammonia concentrationwas 4.4 mol/L, the rod-like PbTiO3nanocrystals with highly crystalline were successfully synthesized. As the ammoniaconcentration further increased to 13.2 mol/L, the flake-like PbTiO3nanocrystals were formed.

Tumor evolution and intratumor heterogeneity of an oropharyngeal squamous cell carcinoma revealed by whole-genome sequencing.

Zhang, Xinyi Cindy,Xu, Chang,Mitchell, Ryan M,Zhang, Bo,Zhao, Derek,Li, Yao,Huang, Xin,Fan, Wenhong,Wang, Hongwei,Lerma, Luisa Angelica,Upton, Melissa P,Hay, Ashley,M?ndez, Eduardo,Zhao, Lue Ping Stockton Press 2013 Neoplasia Vol.15 No.12

<P>Head and neck squamous cell carcinoma (HNSCC) is characterized by significant genomic instability that could lead to clonal diversity. Intratumor clonal heterogeneity has been proposed as a major attribute underlying tumor evolution, progression, and resistance to chemotherapy and radiation. Understanding genetic heterogeneity could lead to treatments specific to resistant and metastatic tumor cells. To characterize the degree of intratumor genetic heterogeneity within a single tumor, we performed whole-genome sequencing on three separate regions of an human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma and two separate regions from one corresponding cervical lymph node metastasis. This approach achieved coverage of approximately 97.9% of the genome across all samples. In total, 5701 somatic point mutations (SPMs) and 4347 small somatic insertions and deletions (indels)were detected in at least one sample. Ninety-two percent of SPMs and 77% of indels were validated in a second set of samples adjacent to the discovery set. All five tumor samples shared 41% of SPMs, 57% of the 1805 genes with SPMs, and 34 of 55 cancer genes. The distribution of SPMs allowed phylogenetic reconstruction of this tumor's evolutionary pathway and showed that the metastatic samples arose as a late event. The degree of intratumor heterogeneity showed that a single biopsy may not represent the entire mutational landscape of HNSCC tumors. This approach may be used to further characterize intratumor heterogeneity in more patients, and their sample-to-sample variations could reveal the evolutionary process of cancer cells, facilitate our understanding of tumorigenesis, and enable the development of novel targeted therapies.</P>

The updated role of exosomal proteins in the diagnosis, prognosis, and treatment of cancer

Wang Xinyi,Huang Jing,Chen Wenjie,Li Genpeng,Li Zhihui,Lei Jianyong 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Exosomes are vesicles encompassed by a lipid bilayer that are released by various living cells. Exosomal proteins are encapsulated within the membrane or embedded on the surface. As an important type of exosome cargo, exosomal proteins can reflect the physiological status of the parent cell and play an essential role in cell–cell communication. Exosomal proteins can regulate tumor development, including tumor-related immune regulation, microenvironment reconstruction, angiogenesis, epithelial–mesenchymal transition, metastasis, etc. The features of exosomal proteins can provide insight into exosome generation, targeting, and biological function and are potential sources of markers for cancer diagnosis, prognosis, and treatment. Here, we summarize the effects of exosomal proteins on cancer biology, the latest progress in the application of exosomal proteins in cancer diagnosis and prognosis, and the potential contribution of exosomal proteins in cancer therapeutics and vaccines.

Cryptanalysis and Improvement of an Efficient Certificateless Signature Scheme

Li, Jiguo,Huang, Xinyi,Mu, Yi,Wu, Wei The Korea Institute of Information and Commucation 2008 Journal of communications and networks Vol.10 No.1

In traditional digital signature schemes, certificates signed by a trusted party are required to ensure the authenticity of the public key. In Asiacrypt 2003, the concept of certificateless signature scheme was introduced. The advantage of certificateless public key cryptography successfully eliminates the necessity of certificates in the traditional public key cryptography and simultaneously solves the inherent key escrow problem suffered in identity-based cryptography. Recently, Yap et al. proposed an efficient certificateless signature scheme and claimed that their scheme is existentially unforgeable in the random oracle model. In this paper, we show that the certificateless signature scheme proposed by Yap et al. is insecure against public key replacement attacks. Furthermore, we propose an improved certificateless signature scheme, which is existentially unforgeable against adaptive chosen message attacks under the computational Diffie-Hellman assumption in the random oracle model and provide the security proof of the proposed scheme.

The Effect of Beta-Herding on Taiwan’s Market: DCC-MIDAS Approach

Yi Chang Chen Cong Huang,Chunxiu Qiu,Yantong Jin,Xinyi Ma 한국유통과학회 2017 KODISA ICBE (International Conference on Business Vol.2017 No.-

The aim of this study is to investigate the herding of beta transmission between return and volatility. We have used the dynamic conditional correlation model with the mixed-data sampling (DCC-MIDAS) model for the analysis. Evidence demonstrates that herding is a key transmitter in Taiwan’s stock market. The significant estimation of DCC-MIDAS explains the herding phenomenon is highly dynamic and time-varying in herding behavior. By means of time-varying beta of herding based on our rolling forecasting method and robustness check of the Markov switching regression approach using four types of portfolios, we find evidence of superior forecasting ability of the model indicates that there are conditional correlations between betas and herding. The evidence also reveals herding formation in Taiwan’s markets during the subprime crisis period.

Static Var Generator Based on Accurate Linearization Combined with Sliding Mode Controller

Liu Fei,Wang Xueyan,Huang Xinyi,Yan Honglin,Huang Xiangdong,Pan Hongguang 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

The active and reactive current are hard to be decoupled completely with strong robustness when the traditional proportional integral (PI) algorithm is adopted to feedforward decoupling control for static var generator (SVG). This paper proposed a compound control strategy for SVG based on precise linearization and sliding mode control (SMC). To be specifi c, fi rst, the theory of diff erential geometry is used to prove that the mathematical model of SVG satisfi es the necessary and suffi - cient condition of precise linearization. Second, the precise linearized high-order system of SVG was transformed into two completely independent decoupled fi rst-order linear systems, and realize complete decoupling of active current and reactive current. Finally, SMC was used to design both the voltage outer loop and the current inner loop. Simulations ware carried out for the SVG mathematical model under three conditions which were inductive load, capacitive load and sudden change load. The results of those simulation showed that the controller designed by the proposed control strategy has the advantages of quick reactive power compensation, strong robustness and anti-interference performance.

Carotid stiffening predicts cardiovascular risk stratification in mid-life: non-invasive quantification with ultrafast ultrasound imaging

Zhengqiu Zhu,Lingshan Chen,Wenjun Liu,Yiyun Wu,Chong Zou,Xinyi Zhang,Shanshan He,Yinping Wang,Bixiao Shen,Xuehui Ma,Hui Gao,Yun Luan,Hui Huang 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.3

Purpose: The present study investigated the association between Systematic COronary Risk Evaluation (SCORE)-estimated cardiovascular risk and carotid stiffening in a middle-aged population using ultrafast pulse wave velocity (ufPWV).Methods: This study enrolled 683 participants without known cardiovascular disease or diabetes mellitus who underwent ufPWV measurements. Clinical interviews, physical examinations, laboratory findings, carotid intima-media thickness (cIMT), pulse wave velocity (PWV) at the beginning of systole (PWV-BS), and PWV at the end of systole (PWV-ES) were assessed. Each participant underwent an assessment of SCORE risk based on major cardiovascular risk factors (CVRFs), including age, sex, smoking, systolic blood pressure (SBP), and total cholesterol (TC). Crude and adjusted odds ratios (ORs) with 95% confidence intervals and ordinal logistic regression were used. Overall CVRFs were adjusted to assess ORs.Results: cIMT and carotid stiffening in PWV-BS and PWV-ES were significantly different between sex subgroups (all P<0.05), but only PWV-ES increased gradually in age and SCORE-estimated risk subgroups (all P<0.05). Compared with cIMT (r=0.388, P<0.001) and PWV-BS (r=0.159, P<0.001), PWV-ES was more strongly correlated with SCORE categories (r=0.405, P<0.001). Higher PWV-ES values were associated with SCORE categories independently of sex, SBP, TC, and smoking in moderate-risk and high-risk subgroups (OR, 1.63; P<0.001 and OR, 2.12; P=0.024, respectively), but were not independent of age in all risk subgroups (all P>0.05).Conclusion: Carotid stiffening quantified by ufPWV is linked to SCORE categories, and elevated PWV-ES may aid in cardiovascular risk stratification.

Study on the Formation of the Crater and Modified Layer in EDM Titanium Alloys Based on Fluid–Solid Coupled Temperature Field Model

Yini Chen,Changping Li,Shuang Li,Moran Xu,Lei Huang,Shujian Li,Pengnan Li,Xinyi Qiu,Tae Jo Ko 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.3

Electric discharge machining (EDM) is used widely in machining titanium alloys, but the modified layer formed can weaken the mechanical properties of the parts. The present study examined the formation of craters and the evolution of the modified layer (melting layer + heat-affected layer) in RC-type EDM using a fluid–solid coupled temperature field model. This model adopts the level set method to track the liquid–solid two-phase and the driving force equation to control the recoil pressure. The results showed that the discharge energy has a significant effect on the formation of the modified layer. The formation of the modified layer showed phased characteristics with time. The variation law and formation mechanism of the modified layer are described in detail. A verification experiment showed that the diameter and depth of the crater were in good agreement with the simulation results. These results can provide an important reference for EDM to formulate the machining parameters.