Static and Dynamic Output Feedback Control for Polytopic Uncertain Fractional Order Systems with 0 < μ < 1

Xuefeng Zhang,Zerui Han 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.1

The stabilization conditions of fractional order systems (FOS) with order 0 < µ < 1 via two different types of output feedback controls are discussed in this paper. Firstly, by using variable substitution, an alternative condition that guarantees autonomous FOS to be asymptotically stable is proposed, the condition contains only a single variable. Then, based on this stability criterion, the stabilization conditions for FOS and polytopic FOS are given in the form of direct linear matrix inequality. And the obtained results can overcome some drawbacks in the existing work. Furthermore, we extend the results to the singular fractional order case. Finally, the effectiveness of the results is verified by numerical examples.

Removal of Cu2+ from aqueous solution by adsorption onto mercapto functionalized palygorskite

Jun Han,Xuefeng Liang,Yingming Xu,Yuanjian Xu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.23 No.-

In order to enhance sorption capacity of palygorskite for heavy metals, mercapto functionalized palygorskite (MPAL) were prepared and utilized for the sorption of Cu2+ from aqueous solution. Sorption kinetic and thermodynamic experiments were conducted to assess the sorption behavior and application potentials for the remediation of heavy-meta-polluted soil. Sorption mechanisms were investigated by XRD, FT-IR, 29Si CP/MAS NMR, SEM-EDS and XPS in detail. The maximum sorption amount of Cu2+ on MPAL was approximately 30 mg/g, which was 10 times more than pristine palygorskite. Freundlich isotherm describes the sorption data better than other isotherms, and pseudo second order kinetic model fit the sorption kinetic processes well. The positive enthalpy change confirmed that the sorption process of MPAL was endothermic and the positive entropy changes revealed that sorption of Cu2+ was driven by entropy changes. Further characterization analyses and the ‘‘Hard and Soft Acids and Bases theory’’ for mechenism research exhibited the complexation existence of Cu2+ with mercapto groups. The good performance demonstrated that MPAL has great potential application values in removal of heavy metals both from aqueous and soils.

선행스케줄링에서 배타적 자원접근

박학봉(Xuefeng Piao),한상철(Shangchul Han),김희헌(Heeheon Kim),박민규(Minkyu Park),조성제(Seongje Cho),조유근(Yookun Cho) 한국정보과학회 2006 한국정보과학회 학술발표논문집 Vol.33 No.2A

선행스케줄링(pre-scheduling)은 정적인 작업(periodic job)과 동적인 작업(sporadic job)을 유연하게 처리하기 위해 제안된 스케줄링 방식이다. 이 방식은 오프라인 컴포넌트와 온라인 컴포넌트로 구성되며 오프라인 컴포넌트에서는 비주기적으로 도착하는 동적인 작업들을 고려하여 정적인 작업들을 여러 부분작업으로 분할하고, 그리고 각 부분작업들의 실행시간, 준비시간, 마감시간을 부여하고 실행순서를 결정한다. 온라인 컴포넌트에서는 이 정보들을 이용하여 정적인 작업들을 정해진 실행순서에 따라 스케줄하고, 동적인 작업이 도착하면 EDF(Earliest Deadline First) 스케줄링 방식으로 처리한다. 그러나 선행스케줄링에서는 자원공유문제를 고려하지 않고 실행시간을 부여하였으므로 여러 정적인 작업들이 하나의 자원을 공유할 경우에 배타적인 자원접근을 보장하지 못한다. 본 논문에서는 단일처리기 환경에서 여러 정적인 작업들의 자원공유를 고려하여 자원의 배타적 사용을 보장하는 선행스케줄 생성기법을 제시한다. 이 기법은 각 작업의 자원방출시간을 예측하고 예측시간에 근거하여 각 작업의 자원사용구간이 중복되지 않도록 실행시간을 결정한다.

Peroxisome Proliferator-Activated Receptor-Alpha Deficiency Protects Aged Mice from Insulin Resistance Induced by High-Fat Diet

Cha, Dae Ryong,Han, Jee Young,Su, Dong Ming,Zhang, Yahua,Fan, Xuefeng,Breyer, Matthew D.,Guan, Youfei S. Karger AG 2007 American journal of nephrology Vol.27 No.5

<P><I>Background/Aims:</I> Insulin resistance is a central feature of the metabolic syndrome and progressively increases with age, resulting in excessively high incidence of type II diabetes in the elderly population. Peroxisome proliferator-activated receptor-α (PPARα) is widely expressed in insulin target tissues, including those of the liver, kidney, and muscle, where it mediates expression of genes promoting fatty acid β-oxidation. The aim of this study was to evaluate the potential role of PPARα in insulin resistance in aging mice induced by a high-fat diet. <I>Methods:</I> We used male PPARα knockout (KO) mice and wild-type (WT) littermates that were 18 months old. Animals were fed with a high-fat diet (HFD) for 4 weeks, and metabolic parameters associated with insulin sensitivity were assessed. <I>Results:</I> Following HFD treatment, WT mice showed more severe insulin resistance than did mice lacking the PPARα gene, as assessed by both the glucose tolerance test (GTT) and insulin tolerance test (ITT). In addition, WT mice exhibited significantly higher HOMA-IR, plasma total cholesterol levels and urinary albumin-creatinine ratio but less liver weight than did PPARα KO mice. <I>Conclusion:</I> These data suggest that PPARα gene deficiency may protect aged mice from developing insulin resistance and albuminuria induced by a HFD.</P><P>Copyright © 2007 S. Karger AG, Basel</P>

Dual input step‑up inverter with low leakage current for PV generation applications

Kunshu Mu,Chenjin Fei,Xuefeng Hu,Han Xu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

The non-isolated inverter has been widely used in photovoltaic generation applications due to its low cost, reduced size, low weight, and high efficiency. However, when there is no galvanic isolation between the photovoltaic (PV) plant and the grid, leakage current may be generated due to the parasitic capacitor to the ground of the photovoltaic (PV) plant, which brings electromagnetic interference (EMI) and security problems. The main idea of this article is to construct a step-up voltage source inverter with two low-voltage input sources. The proposed inverter integrates a step-up dc–dc converter and a modified step-up dc–dc converter that has the advantages of a simple structure and strong voltage boosting capability. Moreover, the negative polarity of a solar cell and the neutral point of a power grid are linked together, which can greatly reduce the leakage current and improve the reliability and efficiency of the PV system. The operating principle, modulation strategy, and static behavior of the proposed inverter are described in detail. To verify the effectiveness of the proposed structure, a 250w laboratory test setup is established, and test results have been shown.

地方应用型本科高校大学物理课程教学改革与实践

甘新磊(Xinlei Gan),彭雪峰(Xuefeng Peng),韩引霞(Yinxia Han) YIXIN 출판사 2024 教育教学研究论丛 Vol.2 No.4

针对地方应用型本科院校传统大学物理课程教学中存在的四大痛点问题,以学生的发展为中心,基于建构主义教学理论,提出了案例形象化、问题原始化等十大教学策略,并结合慕课及对分课堂各自优点,研究探索了基于“慕课+对分”的“四维度十策略”混合式教学模式。教学实践表明,这种教学模式可以有效的提升学生的学习兴趣和综合能力,课堂教学效果得到明显改进。 Aiming at the four major pain points existing in the traditional college physics teaching in local application-oriented universities, this paper puts forward ten teaching strategies, including case visualization and problem originalization, focusing on the development of students and based on the constructivism teaching theory. The research explored the mixed teaching mode of “four dimensions and ten strategies” based on “MOOCs + PAD”. The teaching practice shows that this teaching mode can effectively enhance students’ learning interest and comprehensive ability, and the classroom teaching effect has been significantly improved.

Regulatory Mechanism of MicroRNA-145 in the Pathogenesis of Acute Aortic Dissection

Tianbo Li,Chencheng Liu,Lingchao Liu,Han Xia,Yingbin Xiao,Xuefeng Wang,Yong Wang 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.4

Purpose: Previous studies have confirmed that microRNAs play important roles in the pathogenesis of acute aortic dissection(AAD). Here, we aimed to explore the role of miR-145 and its regulatory mechanism in the pathogenesis of AAD. Materials and Methods: AAD tissue samples were harvested from patients with aortic dissection and normal donors. Rat aorticvascular smooth muscle cells (VSMCs) were transfected with miR-145 mimic/inhibitor or negative control mimic/inhibitor. Geneand protein expression was measured in human aortic dissection tissue specimens and VSMCs by qRT-PCR and Western blot. Luciferasereporter assay was applied to verify whether connective tissue growth factor (CTGF) was a direct target of miR-145 inVSMCs. Methyl thiazolyl tetrazolium assay was used to detect VSMC viability. Results: miR-145 expression was downregulated in aortic dissection tissues and was associated with the survival of patients withAAD. Overexpression of miR-145 promoted VSMC proliferation and inhibited cell apoptosis. Moreover, CTGF, which was increasedin aortic dissection tissues, was decreased by miR-145 mimic and increased by miR-145 inhibitor. Furthermore, CTGF wasconfirmed as a target of miR-145 and could reverse the promotion effect of miR-145 on the progression of AAD. Conclusion: miR-145 suppressed the progression of AAD by targeting CTGF, suggesting that a miR-145/CTGF axis may provide apotential therapeutic target for AAD.

Revisiting the Knoevenagel condensations: A universal and flexible bis-ammoniated fiber catalyst for the mild synthesis of α,β-unsaturated compounds

Qianqian Hu,Xian-Lei Shi,Yongju Chen,Xuefeng Han,Peigao Duan,Wenqin Zhang 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

A universal fiber catalyst for the Knoevenagel condensations is presented. The detailed characterization by mechanical properties, elemental analysis, FTIR spectroscopy, and SEM confirmed the rangeability of the fiber catalyst during the full-course. Moreover, the mediated condensations proceeded smoothly with lower catalyst amount (1 mol%) in different solvents of varying polarities and the products were obtained in good to excellent yields (95–99%), and even with water as the solvent could also achieve a series of a,b-unsaturated compounds with nearly quantitative yields at room temperature. Furthermore, the catalyst exhibited excellent flexibility and could be easily recovered and recycled with prominent stability over 10 cycles, and the procedure was operationally convenient and effectively amenable to the gram scale on a simple fixed-bed reactor.

Evaluation of Different Yeast Species for Improving In vitro Fermentation of Cereal Straws

Wang, Zuo,He, Zhixiong,Beauchemin, Karen A.,Tang, Shaoxun,Zhou, Chuanshe,Han, Xuefeng,Wang, Min,Kang, Jinhe,Odongo, Nicholas E.,Tan, Zhiliang Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.2

Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a $3{\times}4$ factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, $0.25{\times}10^7$, $0.50{\times}10^7$, and $0.75{\times}10^7$ colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen ($NH_3$-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The $NH_3$-N concentration and $CH_4$ production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be $0.25{\times}10^7$ cfu/500 mg substrates in vitro.

Epigenetic silencing of UBXN8 contributes to leukemogenesis in t(8;21) acute myeloid leukemia

Yang Erna,Guan Wei,Gong Desheng,Li Jieying,Han Caixia,Zhang Juan,Wang Hong,Kang Synat,Gao Xuefeng,Li Yonghui,Yu Li 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

The formation of the RUNX1-RUNX1T1 fusion protein, resulting from the t(8;21) translocation, is considered to be one of the initiating events of t(8;21) acute myeloid leukemia (AML). However, the mechanisms of the oncogenic mechanism of RUNX1- RUNX1T1 remain unclear. In this study, we found that RUNX1-RUNX1T1 triggers the heterochromatic silencing of UBXN8 by recognizing the RUNX1-binding sites and recruiting chromatin-remodeling enzymes to the UBXN8 promoter region. Decitabine, a specific inhibitor of DNA methylation, upregulated the expression of UBXN8 in RUNX1-RUNX1T1+ AML cell lines. Overexpression of UBXN8 inhibited the proliferation and colony-forming ability of and promoted cell cycle arrest in t(8;21) AML cell lines. Enhancing UBXN8 levels can significantly inhibit tumor proliferation and promote the differentiation of RUNX1-RUNX1T1+ cells in vivo. In conclusion, our results indicated that epigenetic silencing of UBXN8 via methylation of its promoter region mediated by the RUNX1- RUNX1T1 fusion protein contributes to the leukemogenesis of t(8;21) AML and that UBXN8 targeting may be a potential therapeutic strategy for t(8;21) AML. The formation of the RUNX1-RUNX1T1 fusion protein, resulting from the t(8;21) translocation, is considered to be one of the initiating events of t(8;21) acute myeloid leukemia (AML). However, the mechanisms of the oncogenic mechanism of RUNX1-RUNX1T1 remain unclear. In this study, we found that RUNX1-RUNX1T1 triggers the heterochromatic silencing of UBXN8 by recognizing the RUNX1-binding sites and recruiting chromatin-remodeling enzymes to the UBXN8 promoter region. Decitabine, a specific inhibitor of DNA methylation, upregulated the expression of UBXN8 in RUNX1-RUNX1T1 + AML cell lines. Overexpression of UBXN8 inhibited the proliferation and colony-forming ability of and promoted cell cycle arrest in t(8;21) AML cell lines. Enhancing UBXN8 levels can significantly inhibit tumor proliferation and promote the differentiation of RUNX1-RUNX1T1 + cells in vivo. In conclusion, our results indicated that epigenetic silencing of UBXN8 via methylation of its promoter region mediated by the RUNX1-RUNX1T1 fusion protein contributes to the leukemogenesis of t(8;21) AML and that UBXN8 targeting may be a potential therapeutic strategy for t(8;21) AML.