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基于域敏感指向分析的区间运算在软件测试中的应用

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计算机研究与发展 2012年第9期49卷 1852-1862页

作者：周虹伯金大海宫云战网络与交换技术国家重点实验室(北京邮电大学) 北京100876

静态分析由于并不执行源代码,导致无法获取变量在实际运行中的取值,进而对一些和变量取值相关的缺陷检测带来了一定困难.利用符号执行和区间运算技术,虽然可以模拟程序实际执行时变量的可能取值范围,但对于结构体、数组等,由于不能对其... 详细信息

静态分析由于并不执行源代码,导致无法获取变量在实际运行中的取值,进而对一些和变量取值相关的缺陷检测带来了一定困难.利用符号执行和区间运算技术,虽然可以模拟程序实际执行时变量的可能取值范围,但对于结构体、数组等,由于不能对其成员进行独立描述,导致数据流无法支持域敏感分析,对和其成员变量相关的缺陷的检测难以实现,产生很多漏报.基于域敏感指向分析的区间运算模型,在域敏感指向分析模型的基础上对其进行了改进,将复杂数据类型拆分成独立的成员变量进行分析,并提出一种关联抽象取值集的类型系统,该系统可以保守的描述程序在动态执行时变量的可能取值.结合赋值语句的抽象语法定义,给出了该类型系统在数据流计算时的具体推导算法,并将其应用在缺陷检测系统(DTSGCC和DTSCPP)中.选用DTSCPP作为实验平台,对6个C++开源工程进行了测试,并对其数据进行了统计分析,结果表明该方法可以减少漏报,且测试效率与非域敏感版本相当.

关键词：静态分析缺陷检测域敏感指向分析区间运算

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静态缺陷检测中的误报消除技术研究

计算机研究与发展 2012年第9期49卷 1822-1831页

作者：赵云山宫云战周傲王前周虹伯北京邮电大学网络与交换技术国家重点实验室北京100876

误报率是衡量静态缺陷检测工具的重要指标.在对比分析了各种误报消除技术的基础上,提出了一种前向数据流分析结合逆向约束搜索技术的误报消除方法:前向数据流分析的保守数据流解可以用于缺陷状态迭代,并得到初始的缺陷检测结果;根据缺... 详细信息

误报率是衡量静态缺陷检测工具的重要指标.在对比分析了各种误报消除技术的基础上,提出了一种前向数据流分析结合逆向约束搜索技术的误报消除方法:前向数据流分析的保守数据流解可以用于缺陷状态迭代,并得到初始的缺陷检测结果;根据缺陷发生处的数据流特征,逆向搜索可能导致缺陷发生的约束条件,该约束条件可以作为通用约束求解器的输入判断缺陷的可满足性,从而对初始的缺陷检测结果进行精化.同时,在数据流分析过程中引入符号执行技术,不仅提高了数据流分析的精度,且便于约束表示及转化,提高了约束搜索的效率.对SPECCPU2000中11个工程的对比实验表明,前向数据流分析与逆向约束搜索相结合的误报消除方法在增加了有限开销的同时有效地消除了部分误报,且与同类工具相比具有更好的可扩展性.

关键词：误报数据流分析抽象解释约束求解符号执行

基于双闭环的混合储能直流微电网稳定控制策略

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黑龙江电力 2019年第4期41卷 319-323,366页

作者：葛鹏张亚亚吴馥郁安允展周磊南京工程学院电气工程学院

针对光伏发电系统功率输出随机性强、波动性大等问题,利用蓄电池-超级电容对光伏发电系统出力的互补特性,构成蓄电池-超级电容和光伏发电的直流微电网系统。在对比分析控制原理的基础上,提出一种适用于直流微电网混合储能的双闭环PI控... 详细信息

针对光伏发电系统功率输出随机性强、波动性大等问题,利用蓄电池-超级电容对光伏发电系统出力的互补特性,构成蓄电池-超级电容和光伏发电的直流微电网系统。在对比分析控制原理的基础上,提出一种适用于直流微电网混合储能的双闭环PI控制策略,在Matlab/Simulink下搭建超级电容器与蓄电池相结合的混合储能的光伏发电系统模型。仿真结果表明,双闭环控制下的微电网具有更好的暂态响应速度及稳定性。

关键词：光伏发电直流微网双闭环控制混合储能暂态响应

不同杀菌方式对延边酱牛肉挥发性风味物质的影响

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食品科技 2024年第2期49卷 106-110页

作者：李昀展陈俊霞周阳孙德鹏李官浩王娟牟柏德朴春香延边大学农业农村部延边特色高品质牛肉精深加工创新重点实验室延边大学东北寒区肉牛科技创新教育部工程研究中心吉林延吉133002

为探究不同杀菌方式对延边酱牛肉挥发性风味的影响,选择巴氏杀菌、微波杀菌、臭氧杀菌、高温高压杀菌和超声波杀菌5种方式,利用固相微萃取结合气相色谱-质谱联用(Solid phase microextraction combined with gas chromatography-mass sp... 详细信息

为探究不同杀菌方式对延边酱牛肉挥发性风味的影响,选择巴氏杀菌、微波杀菌、臭氧杀菌、高温高压杀菌和超声波杀菌5种方式,利用固相微萃取结合气相色谱-质谱联用(Solid phase microextraction combined with gas chromatography-mass spectrometry,SPME-GC-MS)和电子鼻分析技术对延边酱牛肉挥发性风味进行检测及分离判定。研究结果表明不同杀菌处理后的延边酱牛肉挥发性风味物质存在明显差异。由于臭氧的强氧化作用,酱牛肉中醛类含量显著提升,达到总挥发性化合物含量的64.61%;与未杀菌组相比,高温高压杀菌能更好地保持延边酱牛肉的风味。

关键词：延边酱牛肉杀菌方式挥发性风味物质

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离合器参数对汽车起步抖动影响的研究

装备制造技术 2021年第10期 30-36,49页

作者：徐云展刘夫云周星余汉红胡汝凯桂林电子科技大学广西桂林541004 桂林福达股份有限公司广西桂林541199

起步抖动主要发生在离合器滑磨阶段,其产生的途径可分为离合器的自激振动和强迫振动。针对某车型汽车起步抖动现象,建立汽车传动系统的动力学模型,考虑到离合器主从动盘间的粘滑特性,利用双曲正切摩擦模型来对主从动盘间的摩擦力矩进行... 详细信息

起步抖动主要发生在离合器滑磨阶段,其产生的途径可分为离合器的自激振动和强迫振动。针对某车型汽车起步抖动现象,建立汽车传动系统的动力学模型,考虑到离合器主从动盘间的粘滑特性,利用双曲正切摩擦模型来对主从动盘间的摩擦力矩进行表征,后利用四阶龙格库塔法对模型求解,得到离合器接合过程的动态响应。为研究离合器结构性能参数对汽车起步抖动的影响,分别对不同的静摩擦系数、摩擦系数梯度、主从动盘总成转动惯量、主从动盘总成阻尼、离合器扭转刚度等进行仿真,仿真结果选取从动盘角速度波动值和离合器接合时间作为参考和对比,验证不同的离合器参数对汽车起步抖动的影响,对目标车型的离合器参数进行适当调整,验证调整后汽车起步抖动程度,为离合器设计提供参考。

关键词：离合器起步抖动离合器参数参数优化

Electric-magnetic-force characteristics of rare earth barium copper oxide superconductor high-field coils based on screening effect and strain sensitivity

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Applied Mathematics and Mechanics(English Edition) 2022年第8期43卷 1249-1268页

作者： Wenhai zhou Youhe zhou Key Laboratory of Mechanics on Environment and Disaster in Western China The Ministry of Education of ChinaCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou730000China School of Petrochemical Technology Lanzhou University of TechnologyLanzhou730050China

Rare earth barium copper oxide(REBCO)is the most researched and commercialized second-generation high-temperature superconducting material.Due to the anisotropic structure,strong deformation sensitivity,and central field errors caused by screening current effects,it is still a challenge for commercialization applications.In this study,the transversely isotropic constitutive relationship is selected as the mechanical model based on the structural characteristics of REBCO tapes,and suitable microelements are selected to equate the elastic constants using their average stress-strain relationships.Then,a two-dimensional axisymmetric model for coils wound by single-layer tapes is constructed to analyze the dependence of the electric-magnetic-force distribution in the tape on the strain.Finally,the anisotropic approximation of the homogenized bulk method is used to equate large-turn high-field coils,and the electric-magnetic-force distribution characteristics of the coils with/without screening effects and mechanical strain conditions are investigated,respectively.The results reveal that the mechanical strain has a weakening effect on the electromagnetic field distribution of superconducting tapes,but causes a significant enhancement in the force field distribution.In the presence of 0.5% mechanical strain,the maximum weakening of the peak value of the current density and the critical current density inside the high-field coil can reach about 8% and 13%,respectively,with a nearly 5 times increase in the peak stress.The screening current makes the current field distribution inside the coil improve by about 10 times.The screening current induced magnetic field can reach up to 0.8 T,making the relative error of the high-field coil center up to 7.8%.

关键词： screening current strain sensitivity mechanical behavior rare earth barium copper oxide(REBCO)high-field coil electromagnetic field distribution

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不同运行方式下微网逆变器并网特性比较分析

电工技术 2019年第5期 15-18页

作者：张亚亚葛鹏安允展瞿吉葛家宁周磊南京工程学院电力仿真与控制工程中心江苏南京211167

介绍了逆变器的下垂控制和VSG控制的两种不同的并网控制策略,并分别建立了下垂控制和VSG控制并网时的输出功率方程,分析了下垂控制并网时具有较快响应的原因。借鉴下垂控制的优点,通过对VSG控制方式加入比例微分环节,引入有功输出及有... 详细信息

介绍了逆变器的下垂控制和VSG控制的两种不同的并网控制策略,并分别建立了下垂控制和VSG控制并网时的输出功率方程,分析了下垂控制并网时具有较快响应的原因。借鉴下垂控制的优点,通过对VSG控制方式加入比例微分环节,引入有功输出及有功参考闭环反馈来改善系统的动态特性。仿真结果表明,所提出的优化策略能优化VSG的系统阻尼,改善逆变器并网运行的动态特性。

关键词：逆变器 VSG 下垂控制阻尼特性

Mechanism and characterization of microplastic aging process: A review

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环境科学与工程前沿(英文) 2023年第8期17卷 107-125页

作者： Qinwei Lu Yi zhou Qian Sui Yanbo zhou State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process East China University of Science and TechnologyShanghai 200237China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

With the increasing production of petroleum-based plastics,the problem of environmental pollution caused by plastics has aroused widespread concern.Microplastics,which are formed by the fragmentation of macro plastics,are bio-accumulate easily due to their small size and slow degradation under natural conditions.The aging of plastics is an inevitable process for their degradation and enhancement of adsorption performance toward pollutants due to a series of changes in their physiochemical properties,which significantly increase the toxicity and harm of plastics.Therefore,studies should focus on the aging process of microplastics through reasonable characterization methods to promote the aging process and prevent white pollution.This review summarizes the latest progress in natural aging process and characterization methods to determine the natural aging mechanism of microplastics.In addition,recent advances in the artificial aging of microplastic pollutants are reviewed.The degradation status and by-products of biodegradable plastics in the natural environment and whether they can truly solve the plastic pollution problem have been discussed.Findings from the literature pointed out that the aging process of microplastics lacks professional and exclusive characterization methods,which include qualitative and quantitative analyses.To lessen the toxicity of microplastics in the environment,future research directions have been suggested based on existing problems in the current research.This review could provide a systematic reference for in-depth exploration of the aging mechanism and behavior of microplastics in natural and artificial systems.

关键词： Microplastics Aging Degradation Characterization Mechanism

Open-environment machine learning

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National Science Review 2022年第8期9卷 211-221页

作者： Zhi-Hua zhou National Key Laboratory for Novel Software Technology Nanjing University

Conventional machine learning studies generally assume close-environment scenarios where important factors of the learning process hold invariant. With the great success of machine learning, nowadays, more and more practical tasks, particularly those involving open-environment scenarios where important factors are subject to change, called open-environment machine learning in this article, are present to the community.Evidently, it is a grand challenge for machine learning turning from close environment to open environment. It becomes even more challenging since, in various big data tasks, data are usually accumulated with time, like streams, while it is hard to train the machine learning model after collecting all data as in conventional studies. This article briefly introduces some advances in this line of research,focusing on techniques concerning emerging new classes, decremental/incremental features, changing data distributions and varied learning objectives, and discusses some theoretical issues.

关键词： machine learning artificial intelligence open-environment machine learning open ML