Moment-independence global sensitivity analysis for the system with fuzzy failure state and its Kriging method

For the system with the fuzzy failure state, the effects of the input random variables and the fuzzy failure state on the fuzzy probability of failure for the structural system are studied, and the moment-independence global sensitivity analysis（GSA） model is proposed to quantitatively measure these effects. According to the fuzzy random theory, the fuzzy failure state is transformed into an equivalent new random variable for the system, and the complementary function of the membership function of the fuzzy failure state is defined as the cumulative distribution function（CDF） of the new random variable. After introducing the new random variable, the equivalent performance function of the original problem is built. The difference between the unconditional fuzzy probability of failure and conditional fuzzy probability of failure is defined as the moment-independent GSA index. In order to solve the proposed GSA index efficiently, the Kriging-based algorithm is developed to estimate the defined moment-independence GSA index. Two engineering examples are employed to verify the feasibility and rationality of the presented GSA model, and the advantages of the developed Kriging method are also illustrated.

基于FUZZY-BN-FTA的厂区架空燃气管道泄漏可能性研究

为研究厂区架空燃气管道泄漏的故的可能性,提出模糊数学方法、贝叶斯网络模型以及故障树模型相结合的集成模型。通过GeNIe软件建立架空燃气管道泄漏事故的模糊贝叶斯网络模型;引入Leaky Noisy-or Gate扩展模型对模糊贝叶斯网络中节点的条件概率表进行修正,结合基本事件先验概率预测架空燃气管道泄漏的概率值,并引入3个基本事件重要度确定基本事件的重要性排序,同时进行敏感性分析确定主要影响因素,提出控制措施。研究结果表明:厂区车辆撞击、管道疲劳损耗、管材质量不佳、安装设计不合理、焊接缺陷为导致架空燃气管道泄漏的主要因素。研究结果可为工业企业安全管理人员有针对性地制定控制措施,减少事故发生率提供参考。

Stability analysis and controller design of T-S fuzzy systems with time-delay under imperfect premise matching

The issue of the stability and controller design of Takagi-Sugeno（T-S） fuzzy control systems with time-delay is investigated under imperfect premise matching when the T-S fuzzy time-delay model and fuzzy controller do not share the same membership functions.A new stability criterion which contains the information of membership functions is derived.The new stability criterion is less conservative,and enhances the design flexibility.Two numerical examples are presented to illustrate the conservativeness and effectiveness of the proposed method.

Bio-Inspired Numerical Analysis of COVID-19 with Fuzzy Parameters

Fuzziness or uncertainties arise due to insufficient knowledge,experimental errors,operating conditions and parameters that provide inaccurate information.The concepts of susceptible,infectious and recovered are uncertain due to the different degrees in susceptibility,infectivity and recovery among the individuals of the population.The differences can arise,when the population groups under the consideration having distinct habits,customs and different age groups have different degrees of resistance,etc.More realistic models are needed which consider these different degrees of susceptibility infectivity and recovery of the individuals.In this paper,a Susceptible,Infected and Recovered(SIR)epidemic model with fuzzy parameters is discussed.The infection,recovery and death rates due to the disease are considered as fuzzy numbers.Fuzzy basic reproduction number and fuzzy equilibrium points have been derived for the studied model.Themodel is then solved numerically with three different techniques,forward Euler,Runge-Kutta fourth order method(RK-4)and the nonstandard finite difference(NSFD)methods respectively.The NSFD technique becomes more efficient and reliable among the others and preserves all the essential features of a continuous dynamical system.

Stability Analysis of Continuous-Time Fuzzy Large-Scale System

A continuous-time fuzzy large-scale system F consists of some interconnected Takagi-Sugeno fuzzy subsystems. Two sufficient conditions for the asymptotic stability of this system (namely, theorem 1 and theorem 2) are derived via a multiple Lyapunov function approach. In theorem 1, the information of membership functions of fuzzy rules should be known in order to analyze the stability of F. But in general this information is not easy to be acquired for their time-varying property. So theorem 2 is provided to judge the asymptotic stability of F, based on which there is no need to know the information of membership functions in stability analysis. Finally, a numerical example is given to show the utility of the method proposed in this paper.

Effectiveness of Fuzzy Overlay Function for Multi-Criteria Spatial Modeling—A Case Study on Preparation of Land Resources Map for Mawsynram Block of East Khasi Hills District of Meghalaya, India

Multi-criteria spatial modeling is one of the important components of spatial decision support system (SDSS). Multi-criteria spatial modeling often requires a common scale of values for diverse and dissimilar inputs to create an integrated analysis. Weighted overlay function is most commonly used for site suitability analysis which identifies the most preferred locations for a specific phenomenon. However, weighted overlay function gives inconsistent and erroneous results for highly dissimilar inputs as it assumes that most favorable factors result in the higher values of raster, while identifying the best sites. This paper conveys the effectiveness of fuzzy overlay function for multi-criteria spatial modeling. It is based on the principle of fuzzy logic theory which defines membership using Gaussian function on each of the input rasters instead of giving individual rank to them like in weighted overlay function. A case study on preparation of land resources map for Mawsynram block of East Khasi Hills district of Meghalaya, India is presented here. It was observed that fuzzy overlay function has given more satisfactory output in terms of site suitability while comparing with the result of weighted overlay function.

Spatial Analysis and Modelling of Wind Farm Site Suitability in Nasarawa State, North-Central Nigeria

There has been an increasing global and local interest in developing renewable, clean, and cheap energy towards achieving Goal number 7 of the Sustainable Development Goals (SDG). However, decisions involving suitable and sustainable locations for renewable energy projects remain an important task. This study employed Geographic Information System (GIS) and Multi-Criteria Decision Analysis (MCDA) to spatially analyze and model wind farm site suitability in Nasarawa State. The aim is to integrate the environmental, social, and economic aspects of decision-making for identifying sustainable wind farm sites. The study distinguished between two sets of decision criteria: decision constraints and decision factors. The former defined the exclusion zones while the latter were standardized based on fuzzy logic to depict varying degrees of suitability across the State. The MCDA applied the weighted linear combination method, with relative weights generated through pairwise comparisons of the analytic hierarchy process to analyze three policy scenarios: equal weights, environmental/social priority, and economic priority scenario. A combination of resulting composite maps from the constraints and the factors gave the final suitability maps. The resulting suitability index (SI) for the respective policy scenario describes the degrees of suitability: Ideal locations were denoted by one (1) and the not suitable locations by zero (0), with values in-between depicting varying degrees of wind farm site suitability. Based on the SI, priority locations indicating areas with good prospects, in addition to the most suitable parcels of land, were identified and delineated. The composite decision constraint revealed that wind farm projects would not be viable in more than half (57.58%) of the State. Wind speed was the major constraint and accounted for the exclusion of 46.25%, with a mean fuzzy membership value of 0.2008 indicating low suitability across the State. Also, the average acceptable wind farm location for the three-policy scenario was 33.33% of the entire study area. Lafia, Obi, Keana, Awe, Nasarawa-Eggon, Wamba and Kokona LGAs were the identified priority Local Government Areas (LGAs). However, only Lafia, Obi, and Nasarawa-Eggon were consistent with changes in the policy objectives. All the priority LGAs have one or more of the most suitable parcels within their administrative boundaries except for Wamba. Despite the severe limitations of wind speed, substantial parts of Nasarawa State still provide great development potentials for wind energy. The “most suitable” locations in Lafia, Nasarawa-Eggon, and Obi LGAs should have first consideration for the development of wind energy in the State.

Structural Reliability Analysis Method in Fuzzy Environment

In this paper, the fuzzy-set-based structural possibility theory is investigated, and this theory can be used to deal with the subjective uncertainties in the design of engineering structures. Furthermore, a comprehensive model of structural safety assessment, which can merge subjective uncertainties with objective uncertainties, is presented. In this model, the fuzziness of stress-strength inference model, safety margin functions of single or multiple limit-state, structural failure state and the final assessment result are taken into account. This continuous model can be transformed into an equivalent model of probability-based and solved by the present structural reliability analysis method and parallel algorithm. An example is given to show the main idea of the method presented in this paper.

Employment Quality EvaluationModel Based on Hybrid Intelligent Algorithm

In order to solve the defect of large error in current employment quality evaluation,an employment quality evaluation model based on grey correlation degree method and fuzzy C-means(FCM)is proposed.Firstly,it analyzes the related research work of employment quality evaluation,establishes the employment quality evaluation index system,collects the index data,and normalizes the index data;Then,the weight value of employment quality evaluation index is determined by Grey relational analysis method,and some unimportant indexes are removed;Finally,the employment quality evaluation model is established by using fuzzy cluster analysis algorithm,and compared with other employment quality evaluation models.The test results show that the employment quality evaluation accuracy of the design model exceeds 93%,the employment quality evaluation error can meet the requirements of practical application,and the employment quality evaluation effect is much better than the comparison model.The comparison test verifies the superiority of the model.

多维驱动因素联动效应对企业数字化创新的影响——基于SEM与fsQCA的实证分析

随着云计算、大数据、人工智能等数字科技蓬勃发展,数字化创新深刻影响着企业创新与运营模式。利用结构方程模型(SEM)与模糊集定性比较分析方法(fsQCA)分析技术不确定性、市场不确定性、企业家精神、组织学习、组织忘记对企业数字化创新的影响。结果发现:技术不确定性、市场不确定性、企业家精神、组织学习、组织忘记和数字化创新6个要素存在因果线性关系,并发现学习主导型、市场驱动学习型和市场主导型3条数字化创新路径,以及3条非高数字化创新路径。其中,市场驱动学习型最有可能激发数字化创新。结合结构方程模型(SEM)分析结果,比较上述6条路径发现,数字化创新的影响因素具有非对称性,3条非高数字化创新路径并不是3条高数字化创新路径的对立面。

教育数字化战略引领下大学生数字素养培养多组态路径

文章基于活动理论模型,运用fsQCA方法分析教育数字化战略引领下大学生数字素养培养的多组态路径及不同要素之间的联动匹配关系。研究发现,大学生高数字素养培养包括思维主导型、资源任务型、协同驱动型和内涵自主型4条组态路径,不同前因变量之间存在替代关系;数字化思维和评价反馈机制同时存在于4条组态路径中,表明二者是大学生高数字素养不可或缺的前因条件。在此基础上,从学校、教师、学生3个层面提出大学生数字素养培养策略,即落实国家教育数字化战略,优化校园顶层设计;强化教师职业素养,完善人才培养反馈机制;增强数字道德意识,提升学生数字化思维。

商业模式设计如何匹配产业政策以获得高企业绩效——源自中国新能源汽车企业的证据

采用NCA与fsQCA相结合的方法对89家新能源企业进行研究,求解引致企业高水平绩效和低水平绩效的多元路径,探究商业模式设计如何匹配产业政策,进而影响企业绩效。研究发现:①商业模式设计、产业政策等单个要素并不是引致企业高水平绩效和低水平绩效的必要条件;②政府补贴、税收优惠均有助于产生高水平企业绩效,但是低水平低息贷款与低水平企业绩效无关;③不同商业模式设计类型之间可能存在协同效应,新奇型与效率型商业模式设计之间的协同性对实现高水平企业绩效具有关键作用;④产生高水平企业绩效的产业政策与商业模式设计组合可划分为两种类型;⑤相比于技术创新,高水平企业绩效更依赖于资源能力。因此,无论是政府还是企业都应该重视产业政策与商业模式的匹配。

组织文化认同对铁路工程企业员工建言行为的影响研究

为激发铁路工程企业员工建言行为的发生,研究以组织文化认同为切入点,在文献理论分析基础上,基于社会认同理论和自我决定理论,引入情感投入和感知组织支持作为组织文化认同和建言行为间关系的中介变量和调节变量,探究组织文化认同对铁路工程企业员工建言行为影响机理。使用组织文化认同和建言行为等成熟量表,以中国铁道建筑总公司、中国铁路工程总公司,中国交通建设集团有限公司企业员工为研究对象进行问卷调查;运用Mplus8.0和SPSS27.0等分析软件对收集数据进行验证性因子分析、相关性分析;在验证性因子分析和相关性分析的基础上,将建立的结构方程模型通过运用Mplus8.0进行路径假设检验;运用fsQCA3.0进行前因变量对建言行为模糊定性比较分析。结构方程模型检验结果表明,组织文化认同显著正向影响情感投入;情感投入正向影响建言行为;即情感投入在组织文化认同和建言行为影响关系中起中介作用;组织文化认同显著正向影响建言行为;感知组织支持显著正向调节情感投入对建言行为的影响。fsQCA分析结果表明,有5种组态可以发生建言行为,其中组织文化认同3个维度为核心存在条件,与结构方程模型检验结果相符合。以上结果丰富了建言行为边界机制和作用条件,基于“想做”和“能做”二元视角,揭示了组织工作氛围中,组织文化认同对员工产生“想建言”的心理动机产生重要影响,感知组织支持(“能建言”)正向促进了员工将建言的动机转化为实际的建言行为,为铁路工程企业管理者在实践中提供建议和启示。

基于Fuzzy偏好关系的一种方案排序方法

如何根据Ｆｕｚｚｙ 偏好关系选择最优方案或进行方案的排序是一个重要的研究内容·针对Ｆｕｚｚｙ 偏好关系提出了一种新的方案排序方法·首先描述了Ｆｕｚｚｙ 偏好关系及其含义， 然后建立了一个最优化模型并通过求解该模型来得到方案的参考排序值， 使最终方案的排序结果最大程度地反映决策者的偏好， 最后给出了一个算例·

基于有效性分析的自组织模糊神经网络建模方法

提出了一种基于有效性分析的自组织模糊神经网络(self-organizingfuzzyneural network based on effectiveness analysis, SOEFNN)建模方法。首先,提出了一种针对模糊规则的有效性评价指标,利用样本与规则层输出之间的映射关系进行网络模型的有效性分析,通过累积触发的方式实现相应模糊规则的增加或删减,使网络模型在能够处理复杂非线性问题的同时降低其冗余性,使模型更为紧凑。采用梯度下降算法对网络模型进行训练。然后,对所提出的SOEFNN模型进行非线性系统仿真实验和污水处理过程中的出水生化需氧量预测建模,并与其他自组织模糊神经网络模型进行对比。仿真结果表明,所提出的SOEFNN模型能够很好地实现结构和参数的自适应调整,并且具有较好的逼近能力。

基于相关分析和带遗忘因子的随机梯度的非线性系统Wiener模型辨识

实际工业过程往往呈现强非线性和时滞特性,在复杂工况下如何建立过程的高精度模型并对其进行有效控制是研究重点.本文研究了一种基于相关分析的非线性系统Wiener模型辨识.Wiener非线性模型由动态线性子系统和静态非线性子系统串联组成,利用时滞状态空间模型和神经模糊模型分别建立动态线性子系统和静态非线性子系统,并利用设计的组合信号实现Wiener非线性模型分离辨识.首先,利用后移算子的性质,将时滞状态空间模型转化为传递函数模型,在高斯信号作用下利用相关分析方法辨识动态线性子系统的参数,解决了Wiener模型中间变量不可测问题.其次,为了改善辨识模型的精度和收敛速度,推导了带遗忘因子的递推随机梯度方法,得到静态非线性子系统的参数估计.将提出的非线性Wiener模型辨识方法运用于连续搅拌反应釜,实验仿真结果表明,本文提出的Wiener模型辨识方法能够有效辨识连续搅拌反应釜系统,并取得较好的控制效果.

突发灾难事件中舆情发酵机理与内在逻辑研究——基于融知发酵模型

[研究目的]突发灾难事件网络舆情发酵为社会治理带来很大的压力,剖析突发灾难事件中舆情发酵机理,是提高突发灾难网络舆情事件治理精度和效率的实践理据。[研究方法]基于融知发酵模型,采用NCA与fsQCA相融合的方法,选取2018-2022年期间的133个突发灾难舆情事件,以发酵底物、发酵菌株、媒体酶、公众酶、发酵场域、发酵周期为条件变量,以发酵产物为结果变量,探究突发灾难事件舆情的发酵机理和理论模式。[研究结论]研究表明:单个变量对发酵产物的影响是有限的,各变量均不构成发酵产物产生的必要条件;突发灾难事件舆情发酵机理的组态包括10条路径;归纳了交融碰撞型、演化推进型和衍生变异型3种驱动突发灾难事件舆情发酵的理论模式。

平台型企业商业模式创新组态研究——基于共创生态视角

文章基于共生理论构建了涵盖“共创主体—共创网络—共创环境”的平台型企业商业模式创新前因条件联动模型,并结合NCA和fsQCA方法探讨了多维前因条件与平台型企业商业模式创新的必要性和充分性关系。结果表明:单个前因条件并不构成平台型企业商业模式创新的必要条件,但强化共创网络结构嵌入能够发挥较为普适的作用;存在“共创精神-生态联动”等3种引发高水平商业模式创新的组态模式,并且高管企业家精神、用户共创参与以及环境动态性存在互补关系;存在4种引发非高水平商业模式创新的组态模式,表明前因条件与商业模式创新之间属于非对称因果关系。研究结论能够为平台型企业商业模式创新提供实践指导,从而促进平台经济的健康发展。

基于改进FPPN的飞控系统故障传播路径分析方法

针对飞控系统多冗余、多闭环的结构特性,结合有向图模型和模糊Petri网(FPN)模型,构建飞控系统故障传播模糊概率Petri网(FPPN)模型,以解决飞控系统特定结构下的故障传播路径问题。改进的FPPN模型包含飞控系统有向图模型、故障传播特性量化计算模型和故障传播FPPN模型3个部分。采用面向对象技术分析飞控系统的功能行为和物理结构,综合复杂网络理论,构建系统故障传播有向图模型;引入Floyd算法,开展系统耦合关联分析,基于节点的度和边介数定义系统故障传播特性;在有向图模型的基础上,提出相应的结构映射规则,构建飞控系统故障传播FPPN模型,融合改进后的参数量化方法,设定2种推理算法对系统多冗余、闭环结构特性下的故障传播路径进行有效分析。通过数值分析与实例验证,获取飞控系统典型故障传播路径及路径上相关节点的状态值,验证所提方法的有效性。