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Instance selection method for improving graph-based semi-supervised learning

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Frontiers of Computer Science 2018年第4期12卷 725-735页

作者： Hai WANG shao-Bo WANG Yu-feng LI 1 National Key Laboratory for Novel Software Technology Nanjing University Nanjing 210023 China Collaborative Innovation Center of Novel Software Technology and Industrialization Nanjing 210023 China

Graph-based semi-supervised learning is an important semi-supervised learning paradigm. Although graphbased semi-supervised learning methods have been shown to be helpful in various situations, they may adversely affect performance when using unlabeled data. In this paper, we propose a new graph-based semi-supervised learning method based on instance selection in order to reduce the chances of performance degeneration. Our basic idea is that given a set of unlabeled instances, it is not the best approach to exploit all the unlabeled instances; instead, we should exploit the unlabeled instances that are highly likely to help improve the performance, while not taking into account the ones with high risk. We develop both transductive and inductive variants of our method. Experiments on a broad range of data sets show that the chances of performance degeneration of our proposed method are much smaller than those of many state-of-the-art graph-based semi-supervised learning methods.

关键词： graph-based semi-supervised learning performance degeneration instance selection

Low-temperature utilization of CO_2 and CH_4 by combining partial oxidation with reforming of methane over Ru-based catalysts

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Journal of Natural Gas Chemistry 2010年第6期19卷 575-582页

作者： Hongbing ji Danyan feng Yunbing He School of Chemistry and Chemical Engineering The Key Laboratory of Low-carbon Chemistry ＆ Energy Conservation of Guangdong Province Sun Yat-sen University Guangzhou 510275 Guangdong China

Combination of partial oxidation of methane （POM） with carbon dioxide reforming of methane （CRM） has been studied over Ru-based catalysts at 550℃.POM,CRM and combined reaction were performed over 8wt%Ru/γ-Al2O 3 and the results show that both POM and CRM contribute to the combined reaction,between which POM plays a more important ***,the addition of Ce to Ru-based catalyst results in an improvement in the activity and CO selectivity under the adopted reaction *** Ce-doped catalyst was characterized by N2 adsorption-desorption,SEM,XRD,TPR,XPS and in situ *** mechanism has been studied by in situ DRIFTS together with the temperature distribution of catalyst *** mechanism of the combined reaction is more complicated and it is the combination of POM and CRM mechanisms in *** present paper provides a new catalytic system to activate CH4 and CO2 at a rather low temperature.

关键词： combined reaction partial oxidation of methane carbon dioxide reforming of methane synthesis gas ruthenium

A dynamic cellular vertex model of growing epithelial tissues

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Acta Mechanica Sinica 2017年第2期33卷 250-259页

作者： shao-Zhen Lin Bo Li Xi-Qiao feng Institute of Biomechanics and Medical Engineering AMLDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China

Intercellular interactions play a significant role in a wide range of biological functions and processes at both the cellular and tissue scales, for example, embryogenesis, organogenesis, and cancer invasion. In this paper, a dynamic cellular vertex model is presented to study the morphomechanics of a growing epithelial monolayer. The regulating role of stresses in soft tissue growth is revealed. It is found that the cells originating from the same parent cell in the monolayer can orchestrate into clustering patterns as the tissue grows. Collective cell migration exhibits a feature of spatial correlation across multiple cells. Dynamic intercellular interactions can engender a variety of distinct tissue behaviors in a social context. Uniform cell proliferation may render high and heterogeneous residual compressive stresses, while stress-regulated proliferation can effectively release the stresses, reducing the stress heterogeneity in the tissue. The results highlight the critical role of mechanical factors in the growth and morphogenesis of epithelial tissues and help understand the development and invasion of epithelial tumors.

关键词： Soft tissue Cellular vertex model Cell Morphogenesis

Development of Chinese duplex stainless steel in recent years

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Journal of Iron and Steel Research International 2017年第2期24卷 121-130页

作者： Zhi-gang Song Han feng shao-mei Hu Institute for Special Steels Central Iron and Steel Research Institute Beijing 100081 China

The development in research, production, applications, and national standards of Chinese duplex stainless steel （DSS） in recent years was introduced in light of the worldwide development in the field of DSS. The results showed that the output of Chinese DSS increased greatly, and at the same time its grade gradually evolved into a collaborative developing series including the main grade type 2205 and other DSS types in recent years. Economical DSS and super DSS underwent rapid development, especially after 2010. In re- cent years, the application of Chinese DSS has been expanded further not only in traditional application ar- eas such as the petrochemical industry, but also in diverse new fields such as oil and gas transportation, chemical tanker manufacturing, nuclear power plants, and construction. Moreover, due to the increase in output and improvement in quality, as well as applications in Chinese projects, Chinese DSS has also been exported to the Middle East, Eastern Europe, and other regions.

关键词： Duplex stainless steelNitrogen alloyingHot ductilityPrecipitated phase

Automatic video mosaicking algorithm via dynamic key-frame

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Journal of Systems Engineering and Electronics 2020年第2期31卷 272-278页

作者： ji Yufeng LI Weixing feng Kai XING Boyang PAN feng School of Automation Beijing Institute of TechnologyBeijing 100081China Kunming-BIT Industry Technology Research Institute Co. LtdKunming 650106China

Automatic video mosaicking is a challenging task in computer vision. Current researches consider either panoramic or mapping tasks on short videos. In this paper, an automatic mosaicking algorithm is proposed for both mapping and panoramic tasks based on the adapted key-frame on videos of any *** speeded up robust features(SURF) and the grid motion statistic(GMS) algorithm are used for feature extraction and matching between consecutive frames, which are used to compute the transformation. In order to reduce the influence of the accumulated error during image stitching, an evaluation metric is put forward for the transformation matrix. Besides, a self-growth method is employed to stitch the global image for long videos. The algorithm is evaluated by using aerial-view and panoramic videos respectively on the graphic processing unit(GPU) device, which can satisfy the real-time requirement. The experimental results demonstrate that the proposed algorithm is able to achieve a better performance than the state-of-art.

关键词： video mosaicking image stitching speeded up robust feature(SURF) panorama mapping

Differentially Private Distributed Parameter Estimation

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Journal of Systems Science & Complexity 2023年第1期36卷 187-204页

作者： WANG jimin TAN jianwei ZHANG ji-feng School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

Data privacy is an important issue in control systems,especially when datasets contain sensitive information about *** this paper,the authors are concerned with the differentially private distributed parameter estimation problem,that is,we estimate an unknown parameter while protecting the sensitive information of each ***,the authors propose a distributed stochastic approximation estimation algorithm in the form of the differentially private consensus+innovations(DP-CI),and establish the privacy and convergence property of the proposed ***,it is shown that the proposed algorithm asymptotically unbiased converges in mean-square to the unknown parameter while differential privacy-preserving holds for finite number of ***,the exponentially damping step-size and privacy noise for DP-CI algorithm is *** estimate approximately converges to the unknown parameter with an error proportional to the step-size parameter while differential privacy-preserving holds for all *** tradeoff between accuracy and privacy of the algorithm is effectively ***,a simulation example is provided to verify the effectiveness of the proposed algorithm.

关键词： Differential privacy distributed parameter estimation stochastic approximation

Heuristic Benders Decomposition Efficiency Improvement for SCUC

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CSEE Journal of Power and Energy Systems 2021年第4期7卷 889-892页

作者： Chenjia feng Chengcheng shao Biyang Wang Xifan Wang school of Electrical Engineering and Shaanxi Key Laboratory on Smart Grid in Xi'an jiaotong University Xi'an 710049China State Grid Shaanxi Electric Power Company Xi'an 710049China

The Benders Decomposition method is widely used to manage large-scale problems in power system *** this paper,a simple but effective method is proposed to improve the Benders Decomposition efficiency using the security constrained unit commitment(SCUC)problem as an *** heuristic weights are introduced for constraint violations to accelerate their elimination,and thereby improving the Benders Decomposition *** validity of the proposed method is verified through case studies on multiple IEEE test systems.

关键词： Benders Decomposition feasibility cut heuristic weight SCUC

Stability in Inverse Problem of Determining Two Parameters for the Moore-Gibson-Thompson Equation with Memory Terms

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Journal of Systems Science & Complexity 2024年第6期37卷 2368-2389页

作者： FU Songren CHEN Liangbiao ZHANG ji-feng Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Automation and Electrical Engineering Zhongyuan University of TechnologyZhengzhou 450007China

In this paper,the authors consider the inverse problem for the Moore-Gibson-Thompson equation with a memory term and variable diffusivity,which introduce a sort of delay in the dynamics,producing nonlocal effects in *** H¨older stability of simultaneously determining the spatially varying viscosity coefficient and the source term is obtained by means of the key pointwise Carleman estimate for the Moore-Gibson-Thompson *** the sake of generality in mathematical tools,the analysis of this paper is discussed within the framework of Riemannian geometry.

关键词： Carleman estimate memory term Moore-Gibson-Thompson equation stability Riemannian geometry

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共价有机框架材料在金属分离富集中的应用

分析测试学报 2025年第1期44卷 51-60页

作者：李松涛董少锋林月琳孙颖林子俺福州大学化学学院食品安全与生物分析教育部重点实验室福建福州350108

随着工业的发展,重金属及放射性物质的污染加剧,同时对稀有金属的需求上升,因此对金属进行分离富集非常必要。共价有机框架材料(COFs)具有比表面积大、孔隙率高、结晶度高和孔径可调等特点,在金属分离富集领域展现出巨大潜力。通过结合... 详细信息

随着工业的发展,重金属及放射性物质的污染加剧,同时对稀有金属的需求上升,因此对金属进行分离富集非常必要。共价有机框架材料(COFs)具有比表面积大、孔隙率高、结晶度高和孔径可调等特点,在金属分离富集领域展现出巨大潜力。通过结合特定官能团,能够提高COFs对某些金属离子的选择性,COFs材料稳定的共价键连接方式也增强了其在恶劣环境中的稳定性。鉴于此,该文对近年来COFs在金属分离富集中的应用进行了综述,重点对COFs的不同连接方式,及其在贵金属、重金属、稀土元素和放射性元素中的分离富集以及吸附机理进行介绍。最后对COFs在金属分离富集中存在的挑战进行分析,并对未来的研究趋势进行了展望。

关键词：共价有机框架分离富集金属