Robust Attitude Control of Near Space Vehicles with Time-varying Disturbances

Mou Chen,Bin Jiang 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.1

In this paper, the robust attitude control scheme is developed for near space vehicles (NSVs) with time-varying disturbances based on backstepping technique. To efficiently handle the time-varying distur-bance and the system uncertainty, the disturbance observer is employed to estimate them. Using back-stepping technique and the disturbance observer output, the robust attitude control is firstly developed for the NSV. And then, considering the actuator dynamics, another robust attitude control scheme is proposed for the NSV based on the disturbance observer. The uniformly ultimate boundedness of all closed-loop signals are guaranteed via Lyapunov analysis under both developed robust attitude control schemes. Finally, simulation results are presented to illustrate the effectiveness of the proposed attitude control schemes.

Disturbance-Observer-based Robust Control for Time Delay Uncertain Systems

Mou Chen,Wen-Hua Chen 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.2

A robust control scheme is proposed for a class of systems with uncertainty and time delay based on disturbance observer technique. A disturbance observer is developed to estimate the disturbance generated by an exogenous system, and the design parameters of the disturbance observer are determined by solving linear matrix inequalities (LMIs). Based on the output of the disturbance ob-server, a robust control scheme is proposed for the time delay uncertain system. The disturbance-observer-based robust controller is combined of two parts: one is a linear feedback controller designed using LMIs and the other is a compensatory controller designed with the output of the disturbance ob-server. By choosing an appropriate Lyapunov function candidate, the stability of the closed-loop sys-tem is proved. Finally, simulation example is presented to illustrate the effectiveness of the proposed control scheme.

Urodynamic and Bladder Diary Factors Predict Overactive Bladderwet in Women: A Comparison With Overactive Bladder-dry

Sheng-Mou Hsiao,Pei-Chi Wu,Ting-Chen Chang,Chi-Hau Chen,Ho-Hsiung Lin 대한배뇨장애요실금학회 2019 International Neurourology Journal Vol.23 No.1

Purpose: To identify factors predicting the presence of overactive bladder syndrome (OAB)-wet, compared with OAB-dry. Methods: Between September 2007 and September 2013, the medical records of 623 women with OAB who completed a 3-day bladder diary and underwent urodynamic studies in a medical center were retrospectively reviewed. OAB-wet was diagnosed in patients who complained of at least one episode of urgency incontinence in the previous month; otherwise, OABdry was diagnosed. Multivariable logistic regression analysis was used to predict the presence of OAB-wet. Results: Age (odds ratio [OR], 1.05; P<0.001), maximal flow rate (Qmax) (OR,1.06; P<0.001), voided volume (OR, 0.996; P=0.001), detrusor pressure at maximal flow rate (PdetQmax) (OR, 1.02; P=0.003), urgency episodes (OR, 1.04; P<0.001) and urodynamic stress incontinence (OR,1.78; P=0.01) were independent predictors for the presence of OAB-wet vs. OABdry. If we use bladder contractility index as a variable for multivariable logistic regression analysis, bladder contractility index (OR, 1.012; P<0.001) become an independent predictor for OAB-wet. Conclusions: A smaller bladder capacity and more frequent urgency episodes were predictors of OAB-wet, and the above findings indicate that OAB-wet and OAB-dry might be a continuum of OAB. Old age, high Qmax, high PdetQmax and urodynamic stress incontinence were also predictors for OAB-wet, and the above results reveal that OAB-wet and OAB-dry have partially different clinical and urodynamic features. Further studies might be performed to elucidate whether different treatment strategies between OAB-dry and OAB-wet can improve treatment efficacy.

Static Output-feedback Controller Synthesis for Positive Systems under ℓ∞ Performance

Xiaoming Chen,Mou Chen,Liqun Wang,Jun Shen,Jiapan Hu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.11

This paper investigates the ℓ∞-induced output-feedback controller synthesis problem for discrete-time positive systems. For positive linear systems, a necessary and sufficient condition for stability and ℓ∞-induced performance is first put forward using a group of linear inequalities. Then, on the basis of these inequalities, theconditions on which static output-feedback controllers exist are set up, and to solve these conditions, a method of iterative convex optimization is provided. Moreover, a complete solution to the synthesis problem of the controller is proposed based on linear programming for positive systems with single output or input. Finally, two examples are presented to illustrate and verify the effective and applicable methods derived in this paper.

Treatment outcomes of patients with stage II pure endometrioid-type endometrial cancer: a Taiwanese Gynecologic Oncology Group (TGOG-2006) retrospective cohort study

Hung-Chun Fu,Jen-Ruei Chen,Min-Yu Chen,Keng-Fu Hsu,Wen-Fang Cheng,An Jen Chiang,Yu-Min Ke,Yu-Chieh Chen,Yin-Yi Chang,Chia-Yen Huang,Chieh-Yi Kang,Yuan-Yee Kan,Sheng-Mou Hsiao,Ming-Shyen Yen 대한부인종양학회 2018 Journal of Gynecologic Oncology Vol.29 No.5

Objective: Choice of hysterectomy and adjuvant treatment for International Federation of Gynecology and Obstetrics (FIGO) 2009 stage II endometrioid endometrial cancer (EEC) is still controversial. Aims of this study were to evaluate survival benefits and adverse effects of different hysterectomies with or without adjuvant radiotherapy (RT), and to identify prognostic factors. Methods: The patients at 14 member hospitals of the Taiwanese Gynecologic Oncology Group from 1992 to 2013 were retrospectively investigated. Patients were divided into simple hysterectomy (SH) alone, SH with RT, radical hysterectomy (RH) alone, and RH with RT groups. Endpoints were recurrence-free survival (RFS), overall survival (OS), disease-specific survival (DSS), adverse effects and prognostic factors for survival. Results: Total of 246 patients were enrolled. The 5-year RFS, OS, DSS and recurrence rates for the entire cohort were 89.5%, 94.3%, 96.2% and 10.2%, respectively. Patients receiving RH had more adverse effects including blood loss (p<0.001), recurrent urinary tract infections (p=0.013), and leg lymphedema (p=0.038). Age over 50-year (HR=9.2; 95% confidence interval [CI], 1.2–70.9) and grade 3 histology (HR=7.28; 95% CI, 1.45–36.6) were independent predictors of OS. Grade 3 histology was an independent predictor of RFS (HR=5.13; 95% CI, 1.38–19.1) and DSS (HR=5.97; 95% CI, 1.06–58.7). Patients receiving adjuvant RT had lower locoregional recurrence (p=0.046), but no impact on survival. Conclusion: Different treatment modalities yield similar survival outcomes. Patients receiving SH with RT had lower locoregional recurrent with acceptable morbidity. Age and tumor grading remained significant predictors for survival among patients with FIGO 2009 stage II EEC.

Research of Least Privilege for Database Administrators

Mou Shen,Mengdong Chen,Min Li,Lianzhong Liu 보안공학연구지원센터 2013 International Journal of Database Theory and Appli Vol.6 No.6

Drug-induced hyperglycaemia and diabetes: pharmacogenomics perspectives

Mou-Ze Liu,Hai-Yan He,Jian-Quan Luo,Fa-Zhong He,Zhang-Ren Chen,Yi-Ping Liu,Da-Xiong Xiang,Hong-Hao Zhou,Wei Zhang 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.7

Drug-induced diabetes is widely reported inclinical conditions, and it is becoming a global issuebecause of its potential to increase the risk of severe cardiovascularcomplications. However, which drug mechanismsexert their diabetogenic effects and why the effectspresent significant inter-individual differences remain largelyunknown. Pharmacogenomics, which is the study ofhow genomic variation influences drug responses, providesan explanation for individual differences in drug-induceddiabetes. We highlight that pharmacogenomics can beinvolved in regulating the expression of genes in signalingpathways related to the pharmacokinetics or pharmacodynamicsof drugs or the pathogenesis of diabetes, contributingto the differences in drug-induced glucoseimpairment. The pharmacogenomics studies of the majordiabetogenic drugs are reviewed, including calcineurininhibitors, antipsychotics, hormones, and antihypertensivedrugs. We intend to elucidate the genetic basis of druginduceddiabetes and pave the way for the precise use ofthese drugs in the clinic.

Performance analysis of two-dimensional DOA estimation for uniform circular array

Chen Liupeng,Mou Weihua,Lv Zhicheng,Zhang Yonghu,Hu Lizhi,Ou Gang 한국통신학회 2023 ICT Express Vol.9 No.5

Perturbation analysis of direction of arrival (DOA) estimation has been studied mostly on one-dimensional arrays rather than planar arrays, which remains room for exploration. For uniform circular arrays with various model errors, we establish the corresponding system model. Then a performance analysis of the two-dimensional MUSIC algorithm is proposed by first-order error analysis and verified by simulation. The results show that the root-mean-squared error of DOA estimation is proportional to the standard deviation of the model errors, including gain-phase errors, sensor position errors, and mutual coupling effect.

Non-ideal effects on ballooning mode stability in the presence of resonant magnetic perturbations

Mou, M. L.,Jhang, Hogun,Rhee, T.,Chen, S. Y.,Tang, C. J. American Institute of Physics 2018 Physics of plasmas Vol.25 No.8

High yield engineered nanovesicles from ADSC with enriched miR-21-5p promote angiogenesis in adipose tissue regeneration

Sun Di,Mou Shan,Chen Lifeng,Yang Jie,Wang Rongrong,Zhong Aimei,Wang Wei,Tong Jing,Wang Zhenxing,Sun Jiaming 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background: Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have been found to have a great potential for soft tissue repair due to various biological functions, including pro-angiogenesis and low immunogenicity. However, the low yield and heterogeneity of MSC-EVs limited their clinical transformation. This study was designed to develop a novel adipose-derived stem cell engineered nanovesicles (ADSC-NVs) with high production and explore its pro-angiogenetic effect and application in adipose tissue regeneration. Methods: Adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) were isolated from an EVs-free culture medium for human ADSCs (hADSCs). ADSC-NVs were prepared by sequentially extruding ADSCs followed by iodixanol density gradient ultracentrifugation and were compared with ADSC-EVs in morphology, size distribution, protein contents and yield. The pro-angiogenetic effect of ADSC-NVs in different doses (0, 5, 20 and 80 μg/mL) in vitro was determined using transwell assay, tube formation assay, western blot and qRT-PCR. In vivo, BALB/c nude mice were administered injection of a mixture of fat granules and different dose of ADSC-NVs and grafts were harvested at 12 weeks post-transplantation for further analysis. By analyzing the weight and volume of grafts and histological evaluation, we investigated the effect of ADSC-NVs in vessel formation and adipose tissue regeneration. Results: Our results showed yield of purified ADSC-NVs was approximately 20 times more than that of ADSC-EVs secreted by the same number of ADSCs. In vitro, both ADSC-NVs and ADSC-EVs exhibited a dose-dependent proangiogenetic effect, despite their distinct miRNA profiles. These effects of ADSC-NVs may be mediated by enriched miR-21-5p via PTEN inhibition and PI3K/p-Akt signaling activation. Furthermore, after a mixed injection of ADSC-NVs, vessel formation and adipose regeneration were observed in vivo in fat implants. Conclusions: Our study developed a potent alternative of ADSC-EVs. ADSC-NVs have a high pro-angiogenesis potential and can be used as cell-free therapeutic biomaterials in soft tissue regeneration.