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International Journal of Automation and computing 2010年第4期7卷 447-454页

作者： xu-Dong Zhao qing-Shuang Zeng Space Control and Inertial Technology Center Harbin Institute of Technology Harbin 150001 PRC

This paper deals with the H∞ control problems of Markovian jump systems with mode-dependent time delays. First, considering the mode-dependent time delays, a different delay-dependent H∞ performance condition for Markovian jump systems is proposed by constructing an improved Lyapunov-Krasovskii function. Based on this new H∞ disturbance attenuation criterion, a full-order dynamic output feedback controller that ensures the exponential mean-square stability and a prescribed H∞ performance level for the resulting closed-loop system is designed. Illustrative numerical examples are provided to demonstrate the effectiveness of the proposed approach.

关键词： H∞ performance Markovian jump systems time-varying delay output feedback control linear matrix inequality (LMI)

Delay-dependent Stability Analysis for Markovian Jump Systems with Interval Time-varying-delays

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International Journal of Automation and computing 2010年第2期7卷 224-229页

作者： xu-Dong Zhao qing-Shuang Zeng Space Control and Inertial Technology Center Harbin Institute of Technology Harbin 150001 PRC

This paper proposes improved stochastic stability conditions for Markovian jump systems with interval time-varying delays. In terms of linear matrix inequalities （LMIs）, less conservative delay-range-dependent stability conditions for Markovian jump systems are proposed by constructing a different Lyapunov-Krasovskii function. The resulting criteria have advantages over some previous ones in that they involve fewer matrix variables but have less conservatism. Numerical examples are provided to demonstrate the efficiency and reduced conservatism of the results in this paper.

关键词： Stochastic stability Markovian jump systems linear matrix inequality (LMI).

Primary graft dysfunction after liver transplantation

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Hepatobiliary & Pancreatic Diseases International 2014年第2期13卷 125-137页

作者： Xiao-Bo Chen Ming-qing xu Department of Liver and Vascular Surgery West China Hospital Sichuan University

BACKGROUND: Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay and have higher mortality and graft loss rates compared with those without graft dysfunction. However, because of the lack of universally accepted definition, early diagnosis of graft dysfunction is difficult. Additionally, numerous factors affect the allograft function after transplantation, making the prediction of PGD more difficult. The present review was to analyze the literature available on PGD and to propose a *** SOURCE: A search of PubMed (up to the end of 2012) for English-language articles relevant to PGD was performed to clarify the characteristics, risk factors, and possible treatments or interventions for ***: There is no pathological diagnostic standard; many documented definitions of PGD are different. Many factors such as donor status, procurement and transplant process and recipient illness may affect the function of graft, and ischemia reperfusion injury is considered the direct cause. Potentia managements which are helpful to improve graft function were investigated. Some of them are ***: Our analyses suggested that the definition of PGD should include one or more of the following variables: (1)bilirubin ≥10 mg/dL on postoperative day 7; (2) internationa normalized ratio ≥1.6 on postoperative day 7; and (3) alanine aminotransferase or aspartate aminotransferase >2000 IU/L within 7 postoperative days. Reducing risk factors may decrease the incidence of PGD. A majority of the recipients could recover from PGD; however, when the graft progresses intoprimary non-function, the patients need to be treated with retransplantation.

关键词： graft function primary graft dysfunction initial poor function primary non-function liver transplantation

FLUID-STRUCTURE INTERACTION OF HYDRODYNAMIC DAMPER DURING THE RUSH INTO THE WATER CHANNEL

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Journal of Hydrodynamics 2008年第5期20卷 583-590页

作者： xu qing-xin SHEN Rong-ying State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University Shanghai 200240China

The hydrodynamic damper is a device to decrease the motion of armament carrier by use of the water resistance. When hydrodynamic damper rushes into the water channel with high velocity, it is a complicated flow phenomenon with fluid-structure interaction, free surface and moving interface. Numerical simulation using the Smoothed Particle Hydrodynamics （SPH） method coupled with the Finite Element （FE） method was successfully conducted to predict the dynamic characteristics of hydrodynamic damper. The water resistance, the pressure in the interface and the stress of structure were investigated, and the relationship among the peak of water resistance, initial velocity and actual draught was also discussed. The empirical formula was put forward to predict the water resistance. And it is found that the resistance coefficient is commonly in the range of 0.3 ≤ C ≤ 0.5, when the initial velocity is larger than 50 m/s. It can be seen that the SPH method coupled with the FE method has many obvious advantages over other numerical methods for this complicated flow problem with fluid-structure interaction.

关键词： hydrodynamic damper fluid-structure interaction Smoothed Particle Hydrodynamics (SPH) method Finite Element (FE) method

Model fitting of the seasonal population dynamics of the soybean aphid, Aphis glycines Matsumura, in the field

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Journal of Integrative Agriculture 2023年第6期22卷 1797-1808页

作者： xu Lei ZHAO Tong-hua XING Xing xu Guo-qing xu Biao ZHAO Ji-qiu Institute of Plant Protection Liaoning Academy of Agricultural SciencesShenyang 110161P.R.China Agricultural Technology Extension Center of Xiuyan Manchu Autonomous County Anshan 114300P.R.China

The soybean aphid, Aphis glycines Matsumura(Hemiptera: Aphididae), is one of the greatest threats to soybean production, and both trend analysis and periodic analysis of its population dynamics are important for integrated pest management(IPM). Based on systematically investigating soybean aphid populations in the field from 2018 to 2020, this study adopted the inverse logistic model for the first time, and combined it with the classical logistic model to describe the changes in seasonal population abundance from colonization to extinction in the field. Then, the increasing and decreasing phases of the population fluctuation were divided by calculating the inflection points of the models, which exhibited distinct seasonal trends of the soybean aphid populations in each year. In addition, multifactor logistic models were then established for the first time, in which the abundance of soybean aphids in the field changed with time and relevant environmental conditions. This model enabled the prediction of instantaneous aphid abundance at a given time based on relevant meteorological data. Taken as a whole, the successful approaches implemented in this study could be used to build a theoretical framework for practical IPM strategies for controlling soybean aphids.

关键词： soybean aphid population dynamics logistic model inverse logistic model multifactor logistic model

Role of microRNA in liver regeneration

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Hepatobiliary & Pancreatic Diseases International 2016年第2期15卷 141-146页

作者： Peng-Sheng Yi Ming Zhang Ming-qing xu Department of Liver and Vascular Surgery West ChinHospital Sichuan University

BACKGROUND： Liver regeneration is a complex process. micro RNAs（mi RNAs） are short, single-stranded RNAs that modify gene expression at the post-transcriptional level. Recent investigations have revealed that mi RNAs are closely linked to liver *** SOURCES： All included studies were obtained from Pub Med, Embase, the Science Direct databases and Web of Science, with no limitation on publication year. Only studies published in English were ***： We grouped studies that involved mi RNA and liver regeneration into two groups： mi RNAs as promoters and as inhibitors of liver regeneration. We summarized the relevant mi RNAs separately from the related ***： Blocking or stimulating the pathways of mi RNAs in liver regeneration may be novel therapeutic strategies in future regeneration-related liver managements. We may discover additional chemotherapy targets of mi RNA.

关键词： microRNAs liver regeneration gene expression target pathway

Computing for Chinese Cultural Heritage

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Visual Informatics 2022年第1期6卷 1-13页

作者： Meng Li Yun Wang Ying-qing xu Communication University of China Beijing 100024China Beijing University of Posts and Telecommunications Beijing 100876China Beihang University Beijing 100191China Tsinghua University Beijing 100084China

Implementing computational methods for preservation,inheritance,and promotion of Cultural Heritage(CH)has become a research trend across the world since the *** China,generations of scholars have dedicated themselves to studying the country’s rich CH resources;there are great potential and opportunities in the field of computational research on specific cultural artefacts or *** on previous works,this paper proposes a systematic framework for Chinese Cultural Heritage Computing that consists of three conceptual levels which are Chinese CH protection and development strategy,computing process,and computable cultural *** computing process includes three modules:(1)data acquisition and processing,(2)digital modeling and database construction,and(3)data application and *** modules demonstrate the computing approaches corresponding to different phases of Chinese CH protection and development,from digital preservation and inheritance to presentation and *** computing results can become the basis for the generation of cultural genes and eventually the formation of computable cultural ecosystem Case studies on the Mogao caves in Dunhuang and the art of Guqin,recognized as world’s important tangible and intangible cultural heritage,are carried out to elaborate the computing process and methods within the *** continuous advances in data collection,processing,and display technologies,the framework can provide constructive reference for building up future research roadmaps in Chinese CH computing and related fields,for sustainable protection and development of Chinese CH in the digital age.

关键词： Cultural computing Chinese Cultural Heritage Computable cultural ecosystem Mogao caves Guqin

Phase transformation behaviors and mechanical properties of Ti_(50)Ni_(49)Fe_1 alloy with severe plastic deformation

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Rare Metals 2013年第5期32卷 448-452页

作者： Wen Ma Bin Chen Fu-Shun Liu qing xu Division of Science and Technology Information General Research Institute for Nonferrous Metals School of Material Science and Engineering Beijing University of Aeronautics and Astronautics Metrology and Phsico-Chemical Institute Capital Aerospace Machinery Company

In this work, transformation behaviors and mechanical properties of cold-rolled shape memory alloy TisoNia9Fel by severe plastic deformation （SPD） were intensively investigated. The phase transformation behaviors, phase analysis, and microstructures were characterized by differential scanning calorimetry （DSC）, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）, respectively. Tensile testing was performed to analyze the effect of SPD on the mechanical properties and shape memory of TisoNi49Fel alloy. When the thickness reduction is beyond 30 %, the martensitic transformation is suppressed. After cold-rolling, the alloy is mainly com- posed of B2 parent phases with some stress-induced martensitic B 19t phases, and high density of dislocations are generated and the grains are obviously refined. The yield stress ab significantly raises from 618 MPa of 0 % cold rolling to 1,338 MPa of 50 % SPD. Shape-memory effect increases from 6.5 % without cold rolling to 8.5 % after 30 % SPD, ascribed to the induced defects in cold rolling. Those results indicate that TisoNi49Fel alloy has improved mechanical properties and potential commercial applications after SPD.

关键词： TiNiFe alloy Cold-rolling Severe plasticdeformation (SPD) Shape memory effect

LMR-CBT: learning modality-fused representations with CB-Transformer for multimodal emotion recognition from unaligned multimodal sequences

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Frontiers of Computer Science 2024年第4期18卷 39-47页

作者： Ziwang FU Feng LIU qing xu Xiangling FU Jiayin QI School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing 100876China Key Laboratory of Trustworthy Distributed Computing and Service(BUPT) Beijing 100876China Shanghai International School of Chief Technology Officer East China Normal UniversityShanghai 200062China School of Computer Science and Technology East China Normal UniversityShanghai 200062China School of Cyberspace Security Guangzhou UniversityGuangdong 510006China

Learning modality-fused representations and processing unaligned multimodal sequences are meaningful and challenging in multimodal emotion *** approaches use directional pairwise attention or a message hub to fuse language,visual,and audio ***,these fusion methods are often quadratic in complexity with respect to the modal sequence length,bring redundant information and are not *** this paper,we propose an efficient neural network to learn modality-fused representations with CB-Transformer(LMR-CBT)for multimodal emotion recognition from unaligned multi-modal ***,we first perform feature extraction for the three modalities respectively to obtain the local structure of the ***,we design an innovative asymmetric transformer with cross-modal blocks(CB-Transformer)that enables complementary learning of different modalities,mainly divided into local temporal learning,cross-modal feature fusion and global self-attention *** addition,we splice the fused features with the original features to classify the emotions of the ***,we conduct word-aligned and unaligned experiments on three challenging datasets,IEMOCAP,CMU-MOSI,and *** experimental results show the superiority and efficiency of our proposed method in both *** with the mainstream methods,our approach reaches the state-of-the-art with a minimum number of parameters.

关键词： modality-fused representations cross-model blocks multimodal emotion recognition unaligned multimodal sequences computational affection

Transient Appearance of Double Spontaneous-Snakes in EAST H Mode Plasma

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Chinese Physics Letters 2014年第3期31卷 96-98页

作者： xu Li-qing HU Li-Qun ZHANG Zi-Jun Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031

Transient lasting of double spontaneous snakes is observed in energy confinement improved plasma on the EAST tokamak. The destabilization of snakes with superb particle confinement can lower plasma energy confinement and slow plasma toroidal rotation. The non-monotonic q profile with double q=1 surface, slightly above unity in central, is constructed. The prevailing harmonic modes are susceptible to the nearly zero magnetic shear. Finally, the role of anomalous particle transport and the formation of off-axis peaking electron profile on the excitation of double snakes are discussed.

关键词： Magnetoplasma