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High-Impact Bug Report Identification with Imbalanced Learning Strategies

Journal of Computer Science & Technology 2017年第1期32卷 181-198页

作者： Xin-Li Yang David Lo Xin Xia qiao Huang jian-Ling sun College of Computer Science and Technology Zhejiang University Hangzhou 310027 China School of Information Systems Singapore Management University Singapore Singapore

In practice, some bugs have more impact than others and thus deserve more immediate attention. Due to tight schedule and limited human resources, developers may not have enough time to inspect all bugs. Thus, they often concentrate on bugs that are highly impactful. In the literature, high-impact bugs are used to refer to the bugs which appear at unexpected time or locations and bring more unexpected effects （i.e., surprise bugs）, or break pre-existing functionalities and destroy the user experience （i.e., breakage bugs）. Unfortunately, identifying high-impact bugs from thousands of bug reports in a bug tracking system is not an easy feat. Thus, an automated technique that can identify high-impact bug reports can help developers to be aware of them early, rectify them quickly, and minimize the damages they cause. Considering that only a small proportion of bugs are high-impact bugs, the identification of high-impact bug reports is a difficult task. In this paper, we propose an approach to identify high-impact bug reports by leveraging imbalanced learning strategies. We investigate the effectiveness of various variants, each of which combines one particular imbalanced learning strategy and one particular classification algorithm. In particular, we choose four widely used strategies for dealing with imbalanced data and four state-of-the-art text classification algorithms to conduct experiments on four datasets from four different open source projects. We mainly perform an analytical study on two types of high-impact bugs, i.e., surprise bugs and breakage bugs. The results show that different variants have different performances, and the best performing variants SMOTE （synthetic minority over-sampling technique）＋ KNN （K-nearest neighbours） for surprise bug identification and RUS （random under-sampling）＋ NB （naive Bayes） for breakage bug identification outperform the Fl-scores of the two state-of-the-art approaches by Thung et al. and Garcia and Shihab.

关键词： high-impact bug imbalanced learning bug report identification

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Statics, vibration, and buckling of sandwich plates with metamaterial cores characterized by negative thermal expansion and negative Poisson's ratio

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Applied Mathematics and Mechanics(English Edition) 2023年第9期44卷 1457-1486页

作者： qiao ZHANG Yuxin sun National Key Laboratory of Strength and Structural Integrity School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100191China

This paper proposes a three-dimensional(3D)Maltese cross metamaterial with negative Poisson’s ratio(NPR)and negative thermal expansion(NTE)adopted as the core layers in sandwich plates,and aims to explore the relations between the mechanical responses of sandwich composites and the NPR or NTE of the ***,the NPR and NTE of the metamaterial are derived analytically based on energy *** effective elastic modulus and mass density of the 3D metamaterial are obtained and validated by the finite element method(FEM).Subsequently,the general governing equation of the 3D sandwich plate under thermal environments is established based on Hamilton’s principle with the consideration of the von Kármán *** differential quadrature(DQ)FEM(DQFEM)is utilized to obtain the numerical *** is shown that NPR and NTE can enhance the global stiffness of sandwich *** geometric parameters of the Maltese cross metamaterial significantly affect the responses of the thermal stress,natural frequency,and critical buckling load.

关键词： negative Poisson's ratio(NPR) negative thermal expansion(NTE) sand-wich plate vibration buckling

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Novel congestion control approach in wireless multimedia sensor networks

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The Journal of China Universities of Posts and Telecommunications 2011年第2期18卷 1-8页

作者： LIN qiao-min WANG Ru-chuan GUO jian sun Li-juan College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China State Key-lab for Novel Software Technology Nanjing University Nanjing 210093 China

Data generated in wireless multimedia sensor networks （WMSNs） may have different importance and it has been claimed that the network exert more efforts in servicing applications carrying more important information. Nevertheless, importance of packets cannot generally be accurately represented by a static priority value. This article presents a dynamic priority based congestion control （DPCC） approach that makes two major innovations in WMSNs. First, DPCC employs dynamic priority to represent packet importance. Second, it prioritizes the local traffic of motes near the base station when WMSN is highly congested. Simulation results confirm the superior performance of the proposed approach with respect to energy efficiency, loss probability and latency as well.

关键词： wireless multimedia sensor network congestion control quality of service (QoS) dynamic priority

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Study on tidal gravity observations obtained at stations Zhongshan and Changcheng, Antarctic

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Acta Seismologica Sinica(English Edition) 2001年第3期14卷 325-332页

作者： XU jian-qiao Laboratory of Dynamic Geodesy Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China

Based on the international tidal gravity reference values at station Wuhan, the tidal gravity parameters, including the amplitude factors and phase differences are determined accurately by using the observations with three La-Coste-Romberg (LCR) gravimeters (G-589, ET-20 and ET-21) at stations Zhongshan and Changcheng in the Antarctic, respectively. The standard deviations of the determined amplitude factors of the main tidal waves are better than 0.5%. The amplitude of each tidal wave observed at station Zhongshan is much less than that of the same wave at station Changcheng. The differences of amplitude factors in the diurnal band (O1) at these two stations are less than 7% while those in the semi-diurnal band (M2) are larger than 40%. The influences of meteorology factors, such as atmospheric pressure and temperature, on the tidal gravity observations are very obvious. The oceanic loading effects on the tidal gravity are also very prominent. It is found that the amplitude of the final residual vector of every tidal wave reduces significantly after oceanic correction based on the Schwiderski's global co-tides. However, because the local oceanic loading is not taken into account, the discrepancies of amplitude factors of wave O1 observed at Zhongshan from the corresponding values of theoretical tidal model are about 4%, and 9% at Changcheng.

关键词： Antarctic International tidal gravity reference values Stations Zhongshan and Changcheng Theoretical tidal model Tidal gravity observations

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基于改进粒子群算法的光伏逆变器控制参数辨识

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河南理工大学学报（自然科学版） 2025年第1期44卷 124-133页

作者：罗建孙越江丽娟重庆大学输配电装备及系统安全与新技术国家重点实验室重庆400044 国网安徽省电力有限公司培训中心安徽合肥230022

精准的光伏并网逆变器模型是研究大规模光伏接入下电力系统故障特性的重要工具。目的为了解决现有光伏逆变器仿真模型与实际工作中的光伏逆变器特性相差较大的问题,方法提出采用参数辨识的方法构建逆变器的辨识模型。以重庆云阳某1 MW... 详细信息

精准的光伏并网逆变器模型是研究大规模光伏接入下电力系统故障特性的重要工具。目的为了解决现有光伏逆变器仿真模型与实际工作中的光伏逆变器特性相差较大的问题,方法提出采用参数辨识的方法构建逆变器的辨识模型。以重庆云阳某1 MW光伏电站为实际参照模型,首先根据实际工作情况将逆变器的工作区间划分为3个阶段,利用数学扰动法分别对3个阶段中的待辨识参数划分灵敏度高低等级,并由此提出不同阶段不同灵敏度参数分步辨识策略;其次,分阶段采集实际光伏电站工作数据,对该数据进行分析处理,获得各待辨识参数的初始取值范围,设计同步辨识参数实验作为参照;最后提出改进的混沌遗传粒子群优化算法(chaos genetic algorithm of particle swarm optimization,CGAPSO)作为辨识算法,分步分工作阶段辨识相关参数,通过对比参数的同步辨识结果,验证所提方法的优越性,并将辨识结果代入仿真模型。结果结果表明,低灵敏度参数的同步辨识结果误差远超过可接受范围,而CGAPSO分步辨识出的相关参数误差皆在1.1%以下,精度远高于同步辨识结果。结论基于改进粒子群算法构建的辨识模型输出数据与实际逆变器工作数据契合度高,可准确反映逆变器实际工作特性。

关键词：光伏并网逆变器逆变器控制策略参数辨识数学扰动法改进粒子群优化算法

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影响牙髓干细胞成骨及成牙本质分化的相关物理因素及作用机制

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中国组织工程研究 2025年第7期29卷 1531-1540页

作者：孙玉婷吴家媛张剑遵义医科大学口腔医学院贵州省遵义市563000

背景:牙髓干细胞是口腔颌面部组织工程中极具应用潜力的干细胞之一,较骨髓间充质干细胞具有采集方便、伦理问题少以及增殖分化潜能高等优势。目前,除了生物化学等因素外,物理刺激对于牙髓干细胞的成骨/成牙本质分化也起着关键性的作用... 详细信息

背景:牙髓干细胞是口腔颌面部组织工程中极具应用潜力的干细胞之一,较骨髓间充质干细胞具有采集方便、伦理问题少以及增殖分化潜能高等优势。目前,除了生物化学等因素外,物理刺激对于牙髓干细胞的成骨/成牙本质分化也起着关键性的作用。目的:综述影响牙髓干细胞成骨/成牙本质分化的相关物理因素以及可能涉及的信号传导通路作用机制,寻找影响其分化的最佳诱导条件。方法:检索PubMed和中国知网数据库,以“牙髓干细胞,成骨分化,成牙本质分化,低氧,机械力,激光,磁场,微重力”为中文检索词,以“dental pulp stem cells(DPSCs),osteogenesis differentiation,odontoblastic differentiation,hypoxia,mechanical force,laser therapy,magnetic fields,microgravity”为英文检索词,选取与影响牙髓干细胞成骨/成牙本质分化相关物理因素有关的79篇文献进行综述。结果与结论:(1)微环境中直接或间接的物理信号在调控牙髓干细胞定向分化方面展现出了广阔的应用前景。低氧、力学刺激(动静水压力、机械牵张力及剪切力等)、激光、微重力和磁场等相关物理因素对牙髓干细胞的影响以促进成骨/成牙本质分化为主,因口颌系统拥有复杂的力学环境,力学刺激是细胞环境改变的关键物理因素,同时也是组织工程的一个前沿领域,深入探讨牙髓干细胞对力学环境的响应为口腔疾病的诊断及治疗提供新思路。(2)因该领域比较“年轻”,相关因素涉及的设备参数尚未统一,相关结果存在不一致性,未能达成共识,之后应进一步探索及优化相关物理因素的最佳诱导参数及作用条件。(3)支架材料作为组织工程的三要素之一,在牙髓干细胞成骨/成牙本质分化方面也起到了促进作用,同时也推动了材料学的发展及临床技术的进步。(4)其中涉及到的信号通路有Notch,Wnt,MAPK等,关于物理刺激如何调控牙髓干细胞行为的相关生物学基础尚未明确,未来将进一步探究其具体作用机制,为物理因素影响下的牙髓再生及骨组织工程提供新思路。

关键词：牙髓干细胞成骨分化成牙本质分化物理因素力学因素信号通路干细胞组织工程

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Mean estimation over numeric data with personalized local differential privacy

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Frontiers of Computer Science 2022年第3期16卷 183-192页

作者： qiao XUE Youwen ZHU jian WANG College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China School of Cyber Security Gansu University of Political Science and LawLanzhou 730070China

The fast development of the Internet and mobile devices results in a crowdsensing business model,where individuals(users)are willing to contribute their data to help the institution(data collector)analyze and release useful ***,the reveal of personal data will bring huge privacy threats to users,which will impede the wide application of the crowdsensing *** settle the problem,the definition of local differential privacy(LDP)is ***,to respond to the varied privacy preference of users,resear-chers propose a new model,i.e.,personalized local differential privacy(PLDP),which allow users to specify their own privacy *** this paper,we focus on a basic task of calculating the mean value over a single numeric attribute with *** on the previous schemes for mean estimation under LDP,we employ PLDP model to design novel schemes(LAP,DCP,PWP)to provide personalized privacy for each *** then theoretically analysis the worst-case variance of three proposed schemes and conduct experiments on synthetic and real datasets to evaluate the performance of three *** theoretical and experimental results show the optimality of PWP in the low privacy regime and a slight advantage of DCP in the high privacy regime.

关键词： personalized local differential privacy mean estimation crowdsensing model

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Phylogeny and Biogeography of Thuja L. （Cupressaceae）, an Eastern Asian and North American Disjunct Genus

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Journal of Integrative Plant Biology 2005年第6期47卷 651-659页

作者： jian-HuaLI qiao-PingXIANG ArnoldArboretumofHarvardUniversity CambridgeMA02138USA LaboratoryofSystematicandEvolutionaryBotany InstituteofBotanytheChineseAcademyofSciencesBeijing100093China

: In order to develop better insights into biogeographic patterns of eastern Asian and North American disjunct plant genera, sequences of nuclear ribosomal DNA internal transcribed spacer (nr DNA ITS) region were used to estimate interspecific relationships of Thuja L. (Cupressaceae) and infer its biogeography based on the phylogeny. According to the phylogenetic analysis, two clades were recognized. The first clade included Thuja plicata D. Don (western North America) and T. koraiensis Nakai (northeastern Asia), and the second one contained T. occidentalis(Gord.) Carr. (Japan). The ancestral area of Thuja was inferred to be eastern Asia, and two dispersal events were responsible for the modern distribution of Thuja in North America. Both the North Atlantic land bridge and Bering land bridge were possible routes for the migration of ancestral populations to North America.

关键词： biogeography Cupressaceae Thuja nuclear ribosomal DNA internal transcribed spacer phylogeny

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Effects of altitude and slope on the climate–radial growth relationships of Larix olgensis *** in the southern Lesser Khingan Mountains,Northeast China

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Ecological Processes 2022年第1期11卷 618-630页

作者： Jingjing qiao Yujun sun National Forestry&Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry UniversityBeijing 100083China

Background:The relationship between climate and radial growth of trees exhibits spatial variation due to environ-mental ***,elucidation of how the growth–climate responses of trees vary in space is essential for understanding forest growth dynamics to facilitate scientific management with the ongoing global climate *** explore the altitudinal and slope variations of these interactions,tree-ring width chronologies of Larix olgensis *** were analyzed in the southern Lesser Khingan Mountains,Northeast ***:The radial growth of *** exhibited significant 5-to 10-year periodic changes at three altitudes and two slopes,and the frequency change occurred mainly during the early growth stage and after *** radial growth of *** was significantly negatively correlated with September precipitation only at low altitudes,but also with the mean temperature in July–August and the mean maximum temperature in June–August at high *** radial growth of *** at low and middle altitudes as well as on the sunny slope led to a higher demand for moisture,while temperature was the key limiting factor at high altitudes and on the shady ***:The climate–radial growth relationship of *** exhibits altitudinal and slope *** study quantitatively describes the spatially varying growth–climate responses of *** in the southern Lesser Khingan Mountains,which provides basic data for the management of *** forests and the prediction of future climate impacts on forest ecosystems.

关键词： Larix olgensis A.Henry Altitudinal gradient Slope variability Lesser Khingan Mountains

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Augmented reality-based BIM multi-user collaboration system

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The Journal of China Universities of Posts and Telecommunications 2022年第1期29卷 71-80页

作者： sun Heng qiao Xiuquan Shanxi Transportation Planning Survey and Design Institute Company Limited Taiyuan 030024China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

The rapid development of building information modelling(BIM) and its enabling technologies has attracted extensive attention in the field of architecture, engineering and construction(AEC). By combining BIM models with the real world, the potential of BIM can be further exploited with the help of augmented reality(AR) technology. However, a BIM model usually involves a huge amount of data. Considering the limited computing capability of current mobile devices, these applications therefore suffer from significant performance problems, especially model loading and rendering problems. To this end, an AR-based multi-user BIM collaboration system, which can realise the on-demand dynamical loading of the BIM model by using the block-wise loading strategy of model transformation, thus solving the problem of model loading delay, was proposed. In addition, dynamic rendering technology is adopted to solve the problem of rendering lag. Experimental results show that the realisation of virtual-reality fusion and interaction for the BIM model and remote multi-user collaboration can effectively improve work efficiency and intelligence in the engineering field.

关键词： building information modelling augmented reality multi-user collaboration block-wise loading dynamic rendering

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