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H_∞ drift control of time-delayed seismic structures

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Earthquake Engineering and Engineering Vibration 2009年第4期8卷 617-626页

作者： chang-ching chang Department of Civil Engineering Chung Hsing University(NCHU)

In this paper, an optimal H∞ control algorithm was applied to the design of an active tendon system installed at the first story of a multi-story building to reduce its interstory drift due to earthquake excitations. To achieve optimal control performance and to guarantee the stability of the control system, an optimum strategy to select control parameters γ and α was developed. Analytical expressions of the upper and the lower bounds of γ and α were obtained for a single degree-of-freedom system with state feedback control. The selection ranges for both γ and α are graphically defined so that the controlled system is always stable and the control performance is better than by the conventional LQR control algorithm. Numerical results from a controlled three-story building under real earthquake excitations demonstrate that the peak first interstory drift can be significantly reduced with maximum control force around 10% of the building weight. An optimum design flow chart was provided. In addition, for a time-delayed structure, this study gave explicit formulae to calculate the critical values of γ and a. The system stability and control performance can thus be guaranteed even with time delay.

关键词： H∞ control time delay stability analysis active control active tendon system: state feedback control

Efficient and simple synthesis of B_(2)O_(3)-Al_(2)O_(3)nanocomposites assisted by deep eutectic solvent for production of 5-hydroxymethylfurfural from glucose

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Nano Research 2025年第1期18卷 236-248页

作者： Yuchen Wang Kai Rong Shanlei chang Youxing Fang Shaojun Dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China College of Chemistry Jilin UniversityChangchun 130012China

The catalytic conversion of glucose to high valueadded platform chemical 5-hydroxymethylfurfural(HMF)is a promising biorefinery process,and alumina-boria catalysts are considered to be green and mild solid acid catalysts for this catalytic ***,compared to the common synthesis methods with complicated steps,we reported a simple and efficient strategy to prepare B_(2)O_(3)-Al_(2)O_(3)nanocomposites by calcining cost-effective glucose-urea deep eutectic solvent(DES)solution containing the *** prepared B_(2)O_(3)-Al_(2)O_(3)nanocomposites exhibited an open three-dimensional skeleton and two-dimensional porous lamellar substructure,endowing them with a high specific surface area(228.27 m2/g).The introduction of boron changed the ratios of different aluminum species(AlⅣ,AlⅤ,and AlⅥ)and borate species(BO3 and BO4),thus further affecting the acidity and the types of acid sites of the *** prepared B_(2)O_(3)-Al_(2)O_(3)bifunctional acid catalysts possessing abundant Lewis acid sites and adjustable Brønsted acid sites showed complete glucose conversion and 55.38%of HMF yield under the optimum *** study proposed a concise method to synthesize alumina-boria solid acid catalysts assisted by glucose-urea *** hope to extend the application and prospect of this efficient and simple synthesis strategy.

关键词： 5-hydroxymethylfurfural(HMF) deep eutectic solvent glucose alumina-boria acid catalyst

Self-sustained oscillation for compressible cylindrical cavity flows

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Chinese Journal of Aeronautics 2017年第4期30卷 1294-1299页

作者： kung-Ming CHUNG Kuan-Huang LEE Keh-Chin chang Aerospace Science and Technology Research Center National Cheng Kung University Tainan 711 China Department of Aeronautics and Astronautics National Cheng Kung University Tainan 701 China

The presence of a cavity changes the mean and fluctuating pressure distributions. Similarities are observed between a cylindrical cavity and a rectangular cavity for a compressible *** type of cavity flow field depends on the diameter-to-depth ratio and the length-to-depth *** feedback loop is responsible for the generation of discrete acoustic tones. In this study, the selfsustained oscillation for a compressible cylindrical cavity flow was investigated experimentally. For open-type cavities, the power spectra show that the strength of resonance depends on the diameterto-depth ratio（4.43–43.0） and the incoming boundary layer thickness-to-depth ratio（0.72–7.0）. The effective streamwise length is used as the characteristic length to estimate the Strouhal number. At higher modes, there is a large deviation from Rossiter＇s formula for rectangular cavities. The gradient-based searching method was used to evaluate the values of the empirical parameters. Less phase lag and a lower convection velocity are observed.

关键词： Cavity flow Compressible flow Convection velocity Open cavity Oscillation

Interconnections between diabetic corneal neuropathy and diabetic retinopathy:diagnostic and therapeutic implications

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Neural Regeneration Research 2025年第8期20卷 2169-2180页

作者： Mingyi Yu Faith Teo En Ning chang Liu Yu-Chi Liu Tissue Engineering and Stem Cell Group Singapore Eye Research InstituteSingapore Yong Loo Lin School of Medicine National University of SingaporeSingapore Department of Cornea and External Eye Disease Singapore National Eye CenterSingapore Ophthalmology and Visual Sciences Academic Clinical Program Duke-NUS Medical SchoolSingapore

Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes *** corneal neuropathy refers to the progressive damage of corneal *** retinopathy has traditionally been considered as damage to the retinal ***,growing evidence suggests that diabetic retinopathy is a complex neurovascular disorder resulting from dysfunction of the neurovascular unit,which includes both the retinal vascular structures and neural *** retinopathy is one of the leading causes of blindness and is frequently screened for as part of diabetic ocular ***,diabetic corneal neuropathy is commonly overlooked and underdiagnosed,leading to severe ocular surface *** studies have found that these two conditions tend to occur together,and they share similarities in their pathogenesis pathways,being triggered by a status of chronic *** review aims to discuss the interconnection between diabetic corneal neuropathy and diabetic retinopathy,whether diabetic corneal neuropathy precedes diabetic retinopathy,as well as the relation between the stage of diabetic retinopathy and the severity of corneal *** also endeavor to explore the relevance of a corneal screening in diabetic eyes and the possibility of using corneal nerve measurements to monitor the progression of diabetic retinopathy.

关键词： cornea corneal nerves diabetes diabetic corneal neuropathy diabetic retinopathy retina

Modeling for critical state line of granular soil with evolution of grain size distribution due to particle breakage

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Geoscience Frontiers 2020年第2期11卷 473-486页

作者： ching S.chang Yibing Deng Department of Civil and Environmental Engineering University of Massachusetts

Determination of the critical state line(CSL)is important to characterize engineering properties of granular *** size distribution(GSD)has a significant influence on the location of *** influence of particle breakage on the CSL is mainly attributed to the change in GSD due to particle ***,GSD has not been properly considered in modeling the CSL with influence of particle *** study aims to propose a quantitative model to determine the CSL considering the effect of *** hypothesize that the change of critical state void ratio with respect to GSD is caused by the same mechanism that influences of the change of minimum void ratio with respect to ***,the particle packing model for minimum void ratio proposed by chang et al.(2017)is extended to predict critical state void *** developed model is validated by experimental results of CSLs for several types of granular *** the evolution of GSD due to particle breakage is incorporated into the *** model is further evaluated using the experimental results on rockfill material,which illustrates the applicability of the model in predicting CSL for granular material with particle breakage.

关键词： Critical state void ratio Particle breakage Grain size distribution Particle packing model Granular material

A REMARK ON THE PERTURBATION OF CRITICAL MANIFOLDS

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Acta Mathematica Scientia 1991年第3期11卷 298-300页

作者：张恭庆 Inst. of Math. Beking Univ. Beijing China

Given a C~2-function f on a Hilbedrt Riemannian manifold M, let ∑ be a. nondegonerate critical manifold of f, what becomes of ∑, if we perturbe f to f+g? When g is a C~2 perturbation, i.e. ||g||c~2 is small, there w... 详细信息

关键词： A REMARK ON THE PERTURBATION OF CRITICAL MANIFOLDS

Reynolds number effect on compressible cylindrical cavity flow

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Chinese Journal of Aeronautics 2020年第2期33卷 456-464页

作者： kung-Ming CHUNG Yi-Xuan HUANG Kuan-Huang LEE Keh-Chin chang Aerospace Science and Technology Research Center National Cheng Kung UniversityTainan 711China Department of Aeronautics and Astronautics National Cheng Kung UniversityTainan 701China

Presence of a cavity changes the mean and fluctuating pressure distributions inside and near the *** cylindrical cavity flow,the diameter-to-depth ratio is the dominant *** this study,flow is naturally developed along a flat plate with two different lengths,resulting in different incoming boundary layer thicknesses ahead of the *** effect of Reynolds number based on incoming boundary layer thickness on characteristics of mean and fluctuating pressure distributions is *** sensitive paint was also used to visualize the mean surface pressure *** effect of Reynolds number on the classification of compressible cylindrical cavity flow and self-sustained oscillating frequency is not *** increase in Reynolds number results in a reduction in the value of differential pressure or momentum flux near the rear edge.

关键词： Cavity flow Compressible flow Convection velocity Open cavity Oscillation

The fabrication and application of Ni-DNA nanowire-based nanoelectronic devices

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Nano Research 2019年第6期12卷 1293-1300页

作者： Pang-Chia chang Chia-Yu chang Wen-Bin Jian Chiun-Jye Yuan Yu-chang Chen Chia-ching chang Department of Electrophysics "National Chiao Tung University"Hsinchu 30010TaiwanChina Department of Biological Science and Technology "National Chiao Tung University"Hsinchu 30068TaiwanChina Center for Intelligent Drug Systems and Smart Bio-devices(IDS^2B) "National Chiao Tung University"Hsinchu 30068TaiwanChina Institute of Physics "Academia Sinica"Taipei 11529TaiwanChina

DNA is a self-assembled,double stranded natural molecule that can chelate and align nickel ions between its base *** fabrication of a DNA-guided nickel ion chain (Ni-DNA) device was successful,as indicated by the conducting currents exhibiting a Ni ion redox reaction-driven negative differential resistance effect,a property unique to mem-elements (1).The redox state of nickel ions in the Ni-DNA device is programmable by applying an external bias with different polarities and writing times (2).The multiple states of Ni-DNA-based memristive and memcapacitive systems were characterized (3).As such,the development of Ni-DNA nanowire device-based circuits in the near future is proposed.

关键词： DNA-guided nickel ion chain (Ni-DNA) negative differential resistance (NDR) memristive systemmem capacitive system nanowire

New Challenges for Biological Text-Mining in the Next Decade

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Journal of Computer Science & Technology 2010年第1期25卷 169-178,F0003页

作者： Yen-ching chang Richard Tzong-Han Tsai Wen-Lian Hsu Institute of Information Science "Academia Sinica" Department of Computer Science and Engineering Yuan Ze University Department of Computer Science "National Tsing-Hua University"

The massive flow of scholarly publications from traditional paper journals to online outlets has benefited biologists because of its ease to access. However, due to the sheer volume of available biological literature, researchers are finding it increasingly difficult to locate needed information. As a result, recent biology contests, notably JNLPBA and BioCreAtIvE, have focused on evaluating various methods in which the literature may be navigated. Among these methods, text-mining technology has shown the most promise. With recent advances in text-mining technology and the fact that publishers are now making the full texts of articles available in XML format, TMSs can be adapted to accelerate literature curation, maintain the integrity of information, and ensure proper linkage of data to other resources. Even so, several new challenges have emerged in relation to full text analysis, life-science terminology, complex relation extraction, and information fusion. These challenges must be overcome in order for text-mining to be more effective. In this paper, we identify the challenges, discuss how they might be overcome, and consider the resources that may be helpful in achieving that goal.

关键词： bioinformatics database mining method and algorithm text mining