SecMVX:Analysis on the Vulnerability of Multi-Variant Execution

As an active defenses technique,multivariant execution(MVX)can detect attacks by monitoring the consistency of heterogeneous variants with parallel execution.Compared with patch-style passive defense,MVX can defend against known and even unknown vulnerability-based attacks without relying on attack feature information.However,variants generated with software diversity technologies will introduce new vulnerabilities when they execute in parallel.First,we analyze the security of MVX theory from the perspective of formal description.Then we summarize the general forms and techniques for attacks against MVX,and analyze the new vulnerabilities arising from the combination of variant generation technologies.We propose SecMVX,a secure MVX architecture and variant generation technology.Experimental evaluations based on CVEs and SPEC 2006 benchmark show that SecMVX introduces 11.29%of the average time overhead,and avoids vulnerabilities caused by the improper combination of variant generation technologies while keeping the defensive ability of MVX.

Strategic Planning for Equitable RWIS Implementation:A Comprehensive Study Incorporating a Multi-variable Semivariogram Model

This paper extends the previously developed method of optimizing Road Weather Information Systems(RWIS)station placement by unveiling a sophisticated multi-variable semivariogram model that concurrently considers multiple vital road weather variables.Previous research primarily centered on single-variable analysis focusing on road surface temperature(RST).The study bridges this oversight by introducing a framework that integrates multiple critical weather variables into the RWIS location allocation framework.This novel approach ensures balanced and equitable RWIS distribution across zones and aligns the network with areas both prone to traffic accidents and areas of high uncertainty.To demonstrate the effectiveness of this refinement,the authors applied the framework to Maine’s existing RWIS network,conducted a gap analysis through varying planning scenarios and generated optimal solutions using a heuristic optimization algorithm.The analysis identified areas that would benefit most from additional RWIS stations and guided optimal resource utilization across different road types and priority locations.A sensitivity analysis was also performed to evaluate the effect of different weightings for weather and traffic factors on the selection of optimal locations.The location solutions generated have been adopted by MaineDOT for future implementations,attesting to the model’s practicality and signifying an important advancement for more effective management of road weather conditions.

CON-MVX:一种基于容器技术的多变体执行系统

多变体执行是一种网络安全防御技术,其利用软件多样性生成等价异构的执行体,将程序输入分发至多个执行体并行执行,通过监控和比较执行体的状态来达到攻击检测的目的。相较于传统的补丁式被动防御技术,多变体执行不依赖于具体的攻击威胁特征进行分析,而是通过构建系统的内生安全能力来对大多数已知、甚至未知的漏洞做出有效防御。近年来,多变体执行技术在不断改进和完善,但是误报问题是制约其发展的主要因素。本文针对多变体执行产生误报的原因进行了详细分析,并在此基础上提出利用容器技术实现多变体执行系统在解决误报问题上的优势。为提升多变体执行技术的可用性,本文设计并实现了一种基于容器技术的多变体执行系统CON-MVX,有效解决传统多变体执行系统的误报问题。CON-MVX利用多个经过运行时随机化技术构建的异构容器作为执行体,使用可重构的模块化组件和独立的容器管理工具对容器执行体进行编排管理,建立进程间监控器CGMon,在内核层级实现对多个执行体的输入同步和输出裁决。同时,为满足与客户端良好交互性,建立中继端口策略,保证系统运行状态的正常反馈。实验结果表明, CON-MVX在保证安全能力的前提下,能有效降低多变体执行系统的误报率,在双冗余度执行条件下使用SPEC CPU 2006测试集测试时,系统带来的平均额外性能损耗不超过15%。

高可靠信息系统非相似冗余架构中的执行体同步技术

非相似冗余架构被广泛使用到信息系统中,提高系统的安全性和可靠性。非相似冗余架构中的执行体之间存在差异,当系统正常工作时,执行体表现一致,但在面对恶意攻击行为时,执行体会表现出不一致。架构通过比较执行体的表现监控系统、感知威胁,从而提升系统安全可靠性。执行体的同步监控,是所有非相似冗余架构都需要解决的难题。目前没有针对同步技术比较系统性的描述和总结。该文首先对执行体同步问题进行了抽象建模,然后提出基于同步点的同步技术分类方法,并分别对每种技术的基本方式、流行度、优缺点进行了总结。该文还提出了影响同步效果的3个重要指标:同步点、误报率和性能,同时给出了同步技术的数学模型,可用于同步技术的设计评估。最后,结合网络弹性工程领域和软件定义晶上系统领域的发展,指出了同步技术未来的发展潜力和可能的发展方向。

MLST技术分析中国烟草野火病菌遗传多样性

明确烟草野火病菌多位点序列分型(MLST)情况,能为制订有效防治措施和选育品种提供强力技术支撑,并为病菌的生物学特性研究提供新视角。从湖南、重庆等5个产烟省(市)烟草生产区采集烟草野火病样,组织分离并鉴定,应用MLST分型,筛选管家基因,分析供试菌株遗传多样性。结果表明,从湖南等5个产烟省(市)分离获得烟草野火病菌144株,筛选得到Pgi、Pfk和Gap 3个管家基因,共获得92个ST型。以Pgi基因为标准,供试菌株可分出亚群5个,单一群4个,亚群1和亚群2菌株数量较多,亚群1菌株来自5个产烟省(市),此亚群的ST43属于中国主要种群。说明中国烟草野火病菌遗传多态性丰富,烟草品种与病菌组群间不存在关联性。

Combined model based on optimized multi-variable grey model and multiple linear regression

The construction method of background value is improved in the original multi-variable grey model （MGM（1,m）） from its source of construction errors. The MGM（1,m） with optimized background value is used to eliminate the random fluctuations or errors of the observational data of all variables, and the combined prediction model together with the multiple linear regression is established in order to improve the simulation and prediction accuracy of the combined model. Finally, a combined model of the MGM（1,2） with optimized background value and the binary linear regression is constructed by an example. The results show that the model has good effects for simulation and prediction.

Multi-Variable Flocking Control for Multi-Agent Systems via a Received Signal Strength Indicator

A novel flocking control approach is proposed for multi-agent systems by integrating the variables of velocities, motion directions, and positions of agents. A received signal strength indicator （RSSI） is applied as a variable to estimate the inter-distance between agents. A key parameter that contains the local information of agents is defined, and a multi-variable controller is proposed based on the parameter. For the position control of agents, the RSSI is introduced to substitute the distance as a control variable in the systems. The advantages of RSSI include that the relative distance between every two agents can be adjusted through the communication quality under different environments, and it can shun the shortage of the limit of sensors. Simulation studies demonstrate the effectiveness of the proposed control approach.

The Research and Application of Prediction Control in Multi-variable Control Process

The modern industrial control objects become more and more complicated,and higher control quality is required, so a series of new control strategies appear,applied,modified and develop quickly.This paper researches a new control strategy- prediction control-and its application in Multi-Variable Control Process.The research result is worthy for automatic control in pro- cess industry.

ENHANCING GROUND RESOLUTION OF TM6 BASED ON MULTI-VARIATE REGRESSION MODEL AND SEMI-VARIOGRAM FUNCTION

It is well known that Landsat TM images are the most widely used remote sensing data in various fields.Usually,it has 7 different electromagnetic spectrum bands,among which the sixth one has much lower ground resolution compared with the other six bands.Nevertheless,it is useful in the study of rock spectrum reflection,geothermal resources exploration,etc.To improve the ground resolution of TM6 to the level as that of the other six bands is a problem .This paper presents an algorithm based on the combination of multivariate regression model with semivariogram function which can improve the ground resolution of TM6 by "fusing" the data of other six bands.It includes the following main steps: （1） testing the correlation between TM6 and one of TM15,7.If the correlation coefficient between TM6 and another one is greater than a given threshold value,then select the band to the regression analysis as an argument.（2） calculating the size of the template window within which some parameters needed by the regression model will be calculated; （3） replacing the original pixel values of TM6 by those obtained by regression analysis; （4） using image entropy as a measurement to evaluate the quality of the fused image of TM6.The basic mechanism of the algorithm is discussed and the V C ++ program for implementing this algorithm is also presented.A simple application example is given in the last part of this paper,showing the effectiveness of the algorithm.

PRECISE INTEGRAL ALGORITHM BASED SOLUTION FORTRANSIENT INVERSE HEAT CONDUCTION PROBLEMSWITH MULTI-VARIABLES

By modeling direct transient heat conduction problems via finite element method (FEM) and precise integral algorithm, a new approach is presented to solve transient inverse heat conduction problems with multi-variables. Firstly, the spatial space and temporal domain are discretized by FEM and precise integral algorithm respectively. Then, the high accuracy semi-analytical solution of direct problem can be got. Finally, based on the solution, the computing model of inverse problem and expression of sensitivity analysis are established. Single variable and variables combined identifications including thermal parameters, boundary conditions and source-related terms etc. are given to validate the approach proposed in 1-D and 2-D cases. The effects of noise data and initial guess on the results are investigated. The numerical examples show the effectiveness of this approach.

基于多头卷积和差分自注意力的小样本故障诊断方法

轴承是工业设备中使用最广泛的旋转部件之一,如果轴承在故障状况下运行较长时间,将会造成巨大的经济损失并威胁人身安全,因此,对轴承故障诊断进行研究具有十分重要的意义。基于深度学习的故障诊断技术目前日趋成熟,但在小样本情况下存在过拟合、效果不稳定、准确率不高等问题。为了解决这类问题,文中提出了一种融合多头卷积(Multi-Head Convolution,MC)的数据嵌入新算法和差分自注意力(Differential Self-Attention,DSA)机制的Transformer变种模型MDT(Multi-Head Convolu⁃tion and Differential Self-Attention Transformer),以实现端到端的小样本故障诊断。MC算法对样本进行多路径一维卷积,由多通道输出将样本从一维扩展到二维,通过多个卷积核尺寸提取出原样本中各个频域的丰富故障信息。相较于Transformer中原有的点积自注意力机制,DSA机制通过差分为每个特征求得对应的注意力权重向量,从而可从样本中提取出更为深层次的故障特征。MDT继承了Transformer对于处理序列数据的强大能力,可从时域信号中提取更为丰富的故障信息,同时避免了小样本模型中常见的过拟合问题。实验结果表明,该方法在每个故障种类仅有100个训练样本的轴承故障诊断任务中能稳定获得99%以上的测试准确率,具有强抗过拟合性和强鲁棒性。

编译支持的多线程程序多变体执行方法

多变体执行(multi-variant execution, MVX)是目前最流行的主动防御技术之一。理想情况下,当未受到攻击时,多变体执行架构提供正常的程序功能。但不幸的是,当多线程程序在多变体执行架构下运行时,由于各个程序变体中共享资源操作的线程执行顺序不一致,不同变体将会产生状态不一致,从而产生攻击误报,该问题导致了多线程程序难以以多变体执行方式运行。基于多变体执行环境,提出了一种编译支持的多线程程序对共享资源操作的同步编译模型,该模型以共享资源操作为同步点,分析确定多线程程序中对共享资源的操作时机和操作方式,保证各程序变体在运行时多线程对共享资源操作的一致性,从而消除了由此而引起的攻击误报。以LLVM 12.0编译框架为基础,设计实现了基于该同步编译模型的原型系统,并对该原型系统进行了仿真实验测试。实验结果显示,经过原型系统处理的多线程程序在多变体执行架构中的误报率显著降低,表明该同步编译模型作为一种通用性的方法,可有效消除多线程程序在多变体执行架构下运行时的攻击误报,提高了多变体执行的可用性。

多变体系统服务质量及损耗评估方法

多变体系统利用多样化技术和动态冗余策略从架构层面实现系统的高安全性和高可靠性,然而现有研究很少涉及多变体系统服务质量(QoS)的量化评估。针对以上问题,提出一种多变体系统QoS及损耗评估方法。首先,在多变体系统架构形式化建模的基础上,基于QoS属性及权重矩阵提出QoS评估模型和流程,并使用信息熵法则评估QoS属性的重要程度;然后,构造典型的多变体系统测试实例,设计并选取影响系统性能和安全性的QoS属性;最后,量化评估系统的QoS属性权重、QoS值、QoS差异和损耗,其中,性能属性平均损耗15.86个百分点,安全属性增益4.98个百分点。评估结果表明多变体机制存在QoS损耗,但它的安全属性带来了一定程度的QoS增益,可为构造高QoS以及低QoS损耗的多变体系统提供一些参考。

多组学诠释食源性致病菌小菌落变种形成分子机制研究进展

食源性致病菌在环境胁迫下可形成小菌落变种(small colony variants,SCVs),被认为是其抗逆存活的重要调控方式之一。SCVs的形成及防治给食品安全领域带来重大挑战,因为与正常细胞相比,SCVs通常具有较强的耐药性,而且能够抵抗宿主细胞的清除并存活数十年。当条件适宜时,SCVs细胞甚至能够在保持耐药性的同时,重新转变为快速生长细胞。随着生物技术的高速发展,多组学方法在微生物抗逆分子机制研究领域的应用越来越常见。基因组学、转录组学、蛋白质组学、代谢组学和联合组学等手段大大增加研究者对细胞中基因调控及蛋白质表达关键途径的理解。本文就近年来食源性致病菌SCVs诱导途径及多组学诠释SCVs分子机制研究进展进行综述,并对冷链食品中金黄色葡萄球菌SCVs形成机制及低温耐受性研究进行展望,以期为建立针对性的安全控制技术,抑制食品加工中致病菌SCVs形成提供参考。

基于多能互补的储能系统需求响应策略研究

随着双碳目标在电力系统中的不断落实与应用,储能和分布式电源得到了广泛应用,传统受电端正由被动供电向主动需求响应的趋势进行转变。然而,电价政策与分布式电源的随机性等因素会对微电网经济与稳定供电产生较大影响。因此,提出基于多能互补的储能系统需求响应策略研究。首先对电网中多能互补方式与需求响应策略进行建模与优化,其次构建了考虑分时电价政策的微电网储能需求响应管理系统,以最优配置各类用电方式并实现用电成本最优。通过Simulink仿真场景进行案例分析,结果表明所得优化策略可有效降低用电成本。

编译支持的程序栈空间布局运行时随机化方法

多变体执行(Multi-Variant Execution,MVX)是目前最流行的主动防御技术之一,其通过并行运行一组功能等价的异构变体,检测不同变体之间不一致的状态转换实现对攻击行为的识别。多变体执行的防御效果在很大程度上依赖于程序变体之间的异构性,程序变体之间的异构性越高多变体执行的防御效果就越好。为了提高程序变体之间的异构性,文中提出了一种编译支持动静态相结合的程序栈空间布局随机化方法,该方法基于LLVM 12.0编译框架,首先在静态编译阶段根据外部输入获取函数识别程序中的关键变量,定位其栈空间分配指令,并在这些分配指令前添加额外的调用和分配指令,其次在程序运行阶段,利用静态编译时添加的指令在栈空间中的关键变量前进行内存块的随机化填充,从而实现程序运行时内存空间布局随机化。仿真实验结果表明,所提动静结合程序栈空间布局随机化方法可有效提高多变体执行程序间的异构性,对于基于程序内存地址溢出类攻击,不仅提升了其本身的攻击难度,也使得其不能通过不断试探程序地址来进行攻击,有效提高了程序的防御能力。

儿童咳嗽变异性哮喘转为典型哮喘风险调查及列线图预测模型的构建和验证

目的构建儿童咳嗽变异性哮喘转为典型哮喘风险的列线图预测模型并进行验证。方法选择2020年1月至2022年12月我院接诊的306例咳嗽变异性哮喘患儿进行研究。收集可能影响儿童咳嗽变异性哮喘转为典型哮喘相关因素,患儿均随访1年,随访结束后根据《儿童支气管哮喘诊断与防治指南(2016年版)》中典型哮喘诊断标准对患儿进行评估,根据有无转变为典型哮喘将患儿分为两组,比较两组个体因素、环境相关因素及检测指标,以LASSO回归筛选出潜在变量后采用Logistic回归筛选出影响儿童咳嗽变异性哮喘转为典型哮喘的独立性影响因素,依此建立列线图模型并进行验证。结果模型组214例咳嗽变异性哮喘患儿中38例(17.76%)转变为典型哮喘,转变组与未转变组患儿病程、病情严重程度、特应性疾病史、哮喘家族史、治疗依从性、家中使用地毯、家中种养花草、居室酶斑、FVC、FEF 50%、MMEF、FeNO及EOS比较差异具有统计学意义(P<0.05)。以LASSO回归基础上行多因素Logisitc回归分析结果显示:特应性疾病史、哮喘家族史、治疗依从性、家中种养花草、MMEF、FeNO及EOS为儿童咳嗽变异性哮喘转为典型哮喘的独立性影响因素。根据多因素分析结果以R语言建立儿童咳嗽变异性哮喘转为典型哮喘预测列线图模型。ROC分析结果显示,模型组列线图模型预测儿童咳嗽变异性哮喘转为典型哮喘的AUC为0.929[95%CI(0.886~0.972)];验证组AUC为0.914[95%CI(0.864~0.964)]。采用Bootstrap法重复抽样1000次,并以验证组进行验证,校准曲线结果显示:模型组与验证组预测曲线与标准曲线基本拟合,提示模型预测准确度较高。模型组决策曲线分析结果显示:当该列线图模型预测儿童咳嗽变异性哮喘转为典型哮喘的概率阈值为0.15~1.00时,患者的净受益率大于0。结论儿童咳嗽变异性哮喘转为典型哮喘受患儿特应性疾病史、哮喘家族史、治疗依从性等因素的影响,本研究建立列线图模型可用于预测儿童咳嗽变异性哮喘转为典型哮喘风险具有较高的准确度与区分度。

An Efficient Maple Program for Calculating Adomian Polynomials

The immense quest for proficient numerical schemes for the solution of mathematical models featuring nonlinear differential equations led to the realization of the Adomian decomposition method (ADM) in the 80th. Undoubtedly, the solution of nonlinear differential equations using ADM is presided over by the acquisition of Adomian polynomials, which are not always easy to find. Thus, the present study proposes easy-to-implement Maple programs for the computation of Adomian polynomials. In fact, the proposed algorithms performed remarkably on several test functions, consisting of one- and multi-variable nonlinearities. Moreover, the introduced programs are advantageous in terms of simplicity;coupled with the requirement of less computational time in comparison with what is known in the literature.

多变体系统风险评估与动态防御方法

多变体系统被提出以从架构层面实现信息系统的高安全和高可靠,但其安全性受到严重挑战。针对此问题,本文基于通用漏洞评分系统(CVSS)提出系统漏洞风险评估模型,对基于K多数裁决的多变体系统进行攻击建模,基于漏洞风险以及攻击行为提出执行体动态切换算法。最后构建了一个典型的多变体系统来评估漏洞风险与系统安全的相关性,以及算法带来的安全增益。评估结果表明,漏洞风险与多变体系统安全呈负相关,且算法约提高了10%~67%的抗攻击能力,该算法能够有效提高系统的安全性。

中国古陶瓷的断源断代

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