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Journal of Systems Science and Systems Engineering 2021年第1期30卷 85-104页

作者： jiachen Sun Peter Gloor MIT Center for Collective Intelligence 245 First StreetCambridgeMA02142USA School of Electronics and Information Technology Sun Yat-Sen UniversityGuangzhou510275China

Rapid advances in machine learning combined with wide availability of online social media have created considerable research activity in predicting what might be the news of tomorrow based on an analysis of the *** this work,we present a deep learning forecasting framework which is capable to predict tomorrow’s news topics on Twitter and news feeds based on yesterday’s content and topic-interaction *** proposed framework starts by generating topics from words using word embeddings and K-means *** temporal topic-networks are constructed where two topics are linked if the same user has worked on both *** and dynamic metrics calculated from networks along with content features and past activity,are used as input of a long short-term memory(LSTM)model,which predicts the number of mentions of a specific topic on the subsequent *** dependencies among topics,our experiments on two Twitter datasets and the HuffPost news dataset demonstrate that selecting a topic’s historical local neighbors in the topic-network as extra features greatly improves the prediction accuracy and outperforms existing baselines.

关键词： Topic’s popularity trend forecasting social media

Systematic principles of surrounding rock control in longwall mining within thick coal seams

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International Journal of Mining Science and Technology 2019年第1期29卷 65-71页

作者： jiachen Wang Zhaohui Wang Faculty of Resources and Safety Engineering China University of Mining&TechnologyBeijing

Effective surrounding rock control is a prerequisite for realizing safe mining in underground coal *** the past three decades, longwall top-coal caving mining(LTCC) and single pass large height longwall mining(SPLL) found expanded usage in extracting thick coal seams in China. The two mining methods lead to large void space left behind the working face, which increases the difficulty in ground *** face failure is a common problem in both LTCC and SPLL mining. Such failure is conventionally attributed to low strength and high fracture intensity of the coal seam. However, the stiffness of main components included in the surrounding rock system also greatly influences longwall face ***, surrounding rock system is developed for LTCC and SPLL faces in this paper. The conditions for simultaneous balance of roof structure and longwall face are put forward by taking the stiffness of coal seam, roof strata and hydraulic support into account. The safety factor of the longwall face is defined as the ratio between the ultimate bearing capacity and actual load imposed on the coal *** influences provided by coal strength, coal stiffness, roof stiffness, and hydraulic support stiffness,as well as the movement of roof structure are analyzed. Finally, the key elements dominating longwall face stability are identified for improving surrounding rock control effectiveness in LTCC and SPLL faces.

关键词： Longwall top coal caving mining Single pass large height longwall mining Surrounding rock system Longwall face stability

Protecting the trust and credibility of data by tracking forgery trace based on GANs

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Digital Communications and Networks 2022年第6期8卷 877-884页

作者： Shuai Xiao jiachen Yang Zhihan Lv School of Electrical and Information Engineering Tianjin UniversityTianjin300072China Department of Game design Faculty of ArtsUppsala UniversitySweden

With the advent of the 5G Internet of Things era,communication and social interaction in our daily life have changed a lot,and a large amount of social data is transmitted to the *** the same time,with the rapid development of deep forgery technology,a new generation of social data trust crisis has also ***,how to ensure the trust and credibility of social data in the 5G Internet of Things era is an urgent problem to be *** paper proposes a new method for forgery detection based on *** first discover the hidden gradient information in the grayscale image of the forged image and use this gradient information to guide the generation of forged *** the classifier,we replace the traditional binary loss with the focal loss that can focus on difficult-to-classify samples,which can achieve accurate classification when the real and fake samples are *** results show that the proposed method can achieve high accuracy on the DeeperForensics dataset and with the highest accuracy is 98%.

关键词： Forgery detection Trace generation Social data Privacy protection

Experimental investigation on the movement mechanism of top coal in steeply inclined ultra-thick coal seams

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Acta Mechanica Sinica 2021年第4期37卷 631-648,I0003页

作者： jiachen Wang Fei Liu Zhaohui Wang School of Energy and Mining Engineering China University of Mining&TechnologyBeijing 100083China Coal Industry Engineering Research Center of Top-Coal Caving Mining Beijing 100083China

The pre-blasting zones have a significant influence on the coal broken and the recovery rate of the top coal caving *** paper explores the coal movement mechanism in the top coal with pre-blasting zones based on the geological parameters of Jiangcang No.1 mine in the western of *** steeply inclined ultra-thick coal seam was mined by using the sublevel top-coal caving mining *** geo-image process system(GIPS)software was used to track the mark points on the coal and *** support was used to record the load on the top of the support during the caving mining *** results show that the horizontal coal is moved to the shield window and the vertical coal is moved downward in the first level,while that in the second level shows consistency for the integrity of the *** vertical displacements of the corresponding points in the first level are lairger than that in the second ***,the load on the top of the support in the first level is smaller than that in the second *** indicated that the pre-blasting zones will give a more loosen top-coal and a small degree of difficulty in the top coal caving.

关键词： Sublevel Top coal caving Pre-blasting Physical modeling Movement mechanism

Entropy-based redundancy analysis and information screening

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Digital Communications and Networks 2023年第5期9卷 1061-1069页

作者： Yang Li jiachen Yang Jiabao Wen School of Electrical and Information Engineering Tianjin UniversityTianjin300072China College of Mechanical and Electrical Engineering Shihezi UniversityXinjiang832003China

The ongoing data explosion introduced unprecedented challenges to the information security of communication *** images are one of the most commonly used information transmission carriers;therefore,their data redundancy analysis and screening are of great ***,most of the current research focus on the algorithm improvement of commonly used image ***,we should consider an important question:Is there data redundancy in the open datasets?Considering the factors of model structures and data distribution to ensure the generalization,we conducted extensive experiments to compare the average accuracy based on few random data to the baseline accuracy based on all *** results show serious data redundancy in the open datasets from different *** instance,with the aid of deep model,only 20%data can achieve more than 90%of the baseline ***,we proposed a novel entropy-based information screening method,which outperforms the random sampling under many experimental *** particular,considering 20%of data,for the shallow model,the improvement is approximately 10%,and for the deep model,the ratio to the baseline accuracy increases to greater than 95%.Moreover,this work can also serve as a new way of learning from a few valuable samples,compressing the size of existing datasets and guiding the construction of high-quality datasets in the future.

关键词： Sampling Quality assessment Data mining Low-shot Few-shot

Exploration on the stability conditions in bubble columns by noncooperative game theory

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Chinese Journal of Chemical Engineering 2022年第10期50卷 75-84页

作者： jiachen Liu Xiaoping Guan Ning Yang State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

The energy-minimization multiscale(EMMS)model,originally proposed for gas-solid fluidization,features a stability condition to close the simplified conservation *** was put forward to physically reflect the compromise of two dominant mechanisms,i.e.,the particle-dominated with minimal potential energy of particles,and the gas-dominated with the least resistance for gas to penetrate through the particle *** stability condition was then formulated as the minimization of the ratio of these two physical ***,the EMMS approach was later extended to the gas-liquid flow in bubble columns,termed dual-bubble-size *** considers the compromise of two dominant mechanisms,i.e.,the liquid-dominated regime with small bubbles,and the gas-dominated regime with large *** stability condition was then formulated as the minimization of the sum of these two physical ***,the two stability conditions were expressed in different manner,though gas-solid and gas-liquid systems bear some *** addition,both the conditions transform the original multiobjective variational problem into a single-objective *** mathematical formulation of stability condition remains therefore an open *** study utilizes noncooperative game theory and noninferior solutions to directly solve the multi-objective variational problem,aiming to explo re the different pathways of compromise of dominant *** results show that only keeping the single dominant mechanism cannot capture the jump change of gas holdup,which is associated with flow regime *** of dominant mechanisms,noninferior solutions and noncooperative game theory can predict the flow regime ***,the game between the two mechanisms makes the two-bubble structure degenerate and reduce to the single-bubble *** game of the three mechanisms restores the two-bubble *** exploration on the formulation of stability conditions may

关键词： Bubble column Flow regimes Mesoscale Noncooperative gametheory

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不同胚层来源成体干细胞修复周围神经损伤

中国组织工程研究 2025年第19期29卷 4102-4110页

作者：郑家晨杨恩同朱弈舟刘芳海军军医大学基础医学院上海市200433 海军军医大学人体解剖学教研室上海市200433

背景:成体干细胞疗法是周围神经损伤修复与再生领域的研究热点之一。中胚层被视为成体干细胞的理想来源,间充质干细胞具有获得率高、来源广、增殖快等优异性能。而外胚层来源成体干细胞,尤其是神经嵴干细胞,具有神经源性,越来越受到研... 详细信息

背景:成体干细胞疗法是周围神经损伤修复与再生领域的研究热点之一。中胚层被视为成体干细胞的理想来源,间充质干细胞具有获得率高、来源广、增殖快等优异性能。而外胚层来源成体干细胞,尤其是神经嵴干细胞,具有神经源性,越来越受到研究人员的关注。目的:对来自外胚层和中胚层的多功能成体干细胞在周围神经损伤修复与再生中的作用及机制进行简要综述,探究不同来源成体干细胞的研究进展与应用前景,并结合临床研究,探讨成体干细胞疗法潜在的应用价值以及亟待解决的问题。方法:第一作者于2024年2月应用计算机在PubMed和SinoMed数据库检索2001年12月至2024年2月相关文献,以“ectodermal stem cells,mesenchymal stem cells,peripheral nerve injury,repair,regeneration”为英文检索词,以“外胚层干细胞、间充质干细胞、周围神经损伤、修复、再生”为中文检索词,最终纳入69篇文献进行分析论述。结果与结论:①外胚层来源成体干细胞具有优异的分化和再生潜能,尤其是毛囊神经嵴干细胞、嗅干细胞、牙外胚层干细胞等,具有神经源性,可在体外表达神经特异性标志物,但目前缺少临床试验研究。②中胚层来源成体干细胞种类多、易获得及纯化,其中骨髓间充质干细胞和脐带间充质干细胞在周围神经损伤修复的应用疗效及安全性方面有相关临床试验支持,能改善感觉及运动神经传导,且在随访中未出现并发症和明显不良反应。骨髓间充质干细胞的获取需行侵入性外科手术且要求患者与捐赠者骨髓配型吻合,应用受到一定限制;而脐带间充质干细胞虽无需侵入性获取,但分离较困难且表型不稳定。③内胚层来源成体干细胞常难以在体外生长,应用受限,目前应用于临床的可能性低。④综合来看,骨髓间充质干细胞仍为周围神经损伤干细胞治疗的首选细胞,适用于无外科手术禁忌且符合配型要求的情况,其次为脐带间充质干细胞,辅以分离方法的改进和表型稳定性的提高策略。⑤牙外胚层干细胞以及脂肪间充质干细胞具有较高应用潜能,有待进一步临床试验,其他外胚层、中胚层来源成体干细胞各以其优异特性在动物及细胞实验研究中具有显著优势。

关键词：成体干细胞周围神经损伤毛囊神经嵴干细胞嗅干细胞牙外胚层干细胞骨髓间充质干细胞脐带间充质干细胞羊水间充质干细胞皮肤干细胞肌肉间充质干细胞

Local spatial properties based image interpolation scheme using SVMs

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Journal of Systems Engineering and Electronics 2008年第3期19卷 618-623页

作者： Ma Liyong Shen Yi Ma jiachen School of Information Science and Engineering Harbin Inst. of Technology Weihai 264209 P. R. China

Image interpolation plays an important role in image process applications. A novel support vector machines （SVMs） based interpolation scheme is proposed with increasing the local spatial properties in the source image as SVMs input patterns. After the proper neighbor pixels region is selected, trained support vectors are obtained by training SVMs with local spatial properties that include the average of the neighbor pixels gray values and the gray value variations between neighbor pixels in the selected region. The support vector regression machines are employed to estimate the gray values of unknown pixels with the neighbor pixels and local spatial properties information. Some interpolation experiments show that the proposed scheme is superior to the linear, cubic, neural network and other SVMs based interpolation approaches.

关键词： image processing interpolation support vector machines local spatial properties support vectorregression.

Understanding self-accelerated water diffusion within poly-lactic acid via molecular dynamics simulation

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Chinese Journal of Chemical Engineering 2019年第4期27卷 759-764页

作者： Xiaohui Wang jiachen Li Li Zhang School of Economics and Management Tianjin University of Technology and Education Tianjin 300222 China Department of Chemistry Zhejiang Sci-Tech University XiaSha Higher Education Zone Hangzhou 310018 China

Poly-lactic acid(PLA) is widely used as a controlled drug release material and the diffusion property of water within the polymer matrix is closely related to the drug release profile. This paper studies the water diffusion in PLA by molecular dynamic simulations. Free volume analysis indicates that water molecules are expected to fill in the free volumes of the polymer matrix forming water clusters at low water content. Along with the increase of the water concentration, the polymer starts to swell and the density of the system starts to *** to the high mobility of water within water cluster, the calculated diffusion coefficient dramatically increases along with the incensement of water content. Thus, we conclude that the diffusion of water is a self-accelerate process, with higher mobility of water in the case where more water exists.

关键词： Water diffusion coefficient Controlled release Molecular dynamic simulation

Extended law of corresponding states for percolation threshold of short-range attractive spheres

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Science China(Physics,Mechanics & Astronomy) 2017年第1期60卷 74-75页

作者： jiachen Wei Fan Song Institute of Mechanics Chinese Academy of Sciences School of Engineering Science University of Chinese Academy of Sciences

The percolation threshold(PT)for colloidal system refers to the point at which particles aggregate to form an infinite cluster that spans the suspension[1].It is widely assumed that the percolation transition should follow the concept of scaling,and recent numerical studies[2-5]have shown that the wrapping probability of percolation can be described by the universal scaling functions,which enables the estimation of PTs for different types of system.

关键词： PT Extended law of corresponding states for percolation threshold of short-range attractive spheres