Weighted power means of q-rung orthopair fuzzy information and their applications in multiattribute decision making

Weighted power means with weights and exponents serving as their parameters are generalizations of arithmetic means. Taking into account decision makers' flexibility in decision making, each attribute value is usually expressed by a $q$-rung orthopair fuzzy value ($q$-ROFV, $q\ge 1$), where the former indicates the support for membership, the latter support against membership, and the sum of their $q$th powers is bounded by one. In this paper, we propose the weighted power means of $q$-rung orthopair fuzzy values to enrich and flourish aggregations on $q$-ROFVs. First, the $q$-rung orthopair fuzzy weighted power mean operator is presented, and its boundedness is precisely characterized in terms of the power exponent. Then, the $q$-rung orthopair fuzzy ordered weighted power mean operator is introduced, and some of its fundamental properties are investigated in detail. Finally, a novel multiattribute decision making method is explored based on developed operators under the $q$-rung orthopair fuzzy environment. A numerical example is given to illustrate the feasibility and validity of the proposed approach, and it is shown that the power exponent is an index suggesting the degree of the optimism of decision makers.     

水文水资源学家陈守煜先生学术研究的知识图谱分析

为探索水文水资源学家陈守煜先生学术研究历程及其演变规律,以其335篇文献作为数据基础,采用共现分析等文献计量可视化分析方法,通过文献发表的时间分布、学科和期刊分布、高被引文献分布和研究主题等方面的知识图谱分析,系统分析了陈先生的学术研究历程。结果显示:陈守煜先生学术研究生命周期历时达62年,在其60岁后出现了2个学术创新高峰期;其学术研究特色荟萃于其河渠非恒定流计算、模糊集理论的水文水资源应用、模糊水文水资源学基本理论、模糊聚类-识别-优选统一理论、可变模糊集理论和可变模糊集理论的水文水资源应用6个研究主题,其中主题1为后续的5个模糊水文水资源学创新主题奠定了数值计算的研究方法论,主题2为模糊集现有理论的应用探索,主题3至主题5为面向工程应用的模糊集理论不断深入创新,主题6为可变模糊集理论的应用探索,形成了"紧密结合应用-持续理论创新-创新理论再应用"这种理论与实践互馈的研究特色。他每一阶段的研究目标比较集中、明确,与其研究主题密切对应,显著提高了研究效率;他的学术研究影响广泛,合计被引8554次,缘于他的源头理论创新。陈先生的研究,理论与应用不断互馈,贵在厚积薄发、深入钻研、持续创新,其研究理念和方法论,对水利科学的学术创新研究具有重要的启示作用和深远影响。     

基于模糊多元联系度模型的尾矿库综合安全评价

为准确评价尾矿库的安全等级，以黄金洞尾矿库为例，分析影响尾矿库安全的各因素之间的关系，综合运用模糊多元联系度理论与层次分析法（AHP），建立了包含5个影响因素和26个影响因子的尾矿库综合安全评价模型。由AHP得出各项主、客观指标的权重系数，引入模糊多元联系度理论，综合考虑确定性与不确定性因素，处理综合集成问题，构造隶属函数量化指标的实测值。结果表明：黄金洞尾矿库安全等级为Ⅱ级，尾矿库处于较稳定状态。经比较不确定性因素大小，得出尾矿排放（B₃）>尾矿坝（B₂）>安全管理（B₁）>尾矿输送与回水（B₅）>排洪系统（B₄），说明尾矿排放指标的不确定性因素最大，需对尾矿排放加强管理。该模型得到的评价结果与实际结果相吻合，为尾矿库安全性评价提供了一种可行的方法。     

Study on the influence of maintenance operations on energy consumption and emissions in healthcare centres by fuzzy cognitive maps

The present work is aimed at performing a qualitative analysis of the effect of maintenance intensity on energy consumption, energy costs and emissions in healthcare centres. Most relevant variables involved in the maximization of the building efficiency were determined by means of fuzzy cognitive maps. Twelve variables were observed to show a direct connection to the energy and environmental efficiency as well as to its maintenance condition. The joint effect of these factors was seen to improve the overall performance of the building in terms of efficiency. However, even though maintenance appeared as one of the most highly-rated variables, it did not seem to affect the overall performance by itself, but it was rather due to the synergistic action of the remaining variables. The behaviour of those variables was evidenced to show a significant change for buildings below 1250?m² floor area as compared to those exceeding such threshold value.     

Prediction of rock mass P wave velocity using blasthole drilling information

In this paper, the development of the models for the prediction of rock mass P wave velocity is presented. For model development, the database of 53 cases including widely used and recorded drilling parameters and P wave velocity was constructed from the field studies conducted in 13 open pit lignite mines. Both conventional linear, non-linear multiple regression and Adaptive Neuro Fuzzy Inference System (ANFIS) were used for model development. Prediction performance indicators showed that ANFIS model presented the best performance and it can successfully be used for the preliminary prediction of P wave velocities of rock masses.     

改进模糊划分聚类的协同过滤推荐算法

针对传统协同过滤（CF）推荐算法存在评分矩阵稀疏、扩展性弱和推荐准确率低的缺陷，提出一种改进模糊划分聚类的协同过滤推荐算法（GIFP-CCF+）。在传统基于修正余弦相似度计算方法上，引入时间差因子、热门物品权重因子以及冷门物品权重因子以改善相似度计算结果；同时引入改进模糊划分的GIFP-FCM算法，将属性特征相似的项目聚成一类，构造索引矩阵，同索引间根据项目间的相似度寻找项目最近邻居构成推荐，从而提高协同过滤算法（CF）的精度。通过与Kmeans-CF、FCM-CF和GIFP-CCF算法进行仿真对比实验，证明了GIFP-CCF+算法在推荐结果和推荐精度上具有一定的优越性。     

铝电解关键指标预测方法的研究与应用

为维持铝电解生产的持续性，保证电解槽的物耗稳定和能耗稳定，通过对铝厂数据的挖掘与建模，提出一整套维持电解槽稳定的策略方法，并用于指导实际生产。首先为数据去噪，针对铝厂数据分布特征未知的特点，提出一种无参自适应的模糊聚类方法，通过迭代自适应得到类簇个数和簇中心；根据聚类结果，将铝厂数据按实际意义标签化，提出一种基于距离的连续属性朴素贝叶斯算法，对分类器使用增量思想，使算法动态分类准确率得到提高；应用单槽测试集数据，通过累积法完成当天各指标等级趋势的预测，确定各指标下变量相对于前一天的变化量，完成预测。实验发现，预测模型可完成铝电解关键指标的预测；提出的聚类、分类算法在UCI数据及铝厂数据上表现良好。     

重力坝坝基多斜面抗滑稳定模糊体系可靠度研究

以基岩具有多斜面、多滑移通道的某实际重力坝工程为例,基于刚体极限平衡法,采用模糊理论和几种典型的体系可靠度计算方法,研究其典型坝段的坝基深层抗滑稳定模糊体系可靠度,探讨模糊理论中隶属函数形式、隶属度以及隶属函数中关键参数的取值对可靠度计算结果的影响。研究结果表明,采取限制失效概率模糊界限比的方法可使计算结果更具有参考性,考虑模糊性的抗滑稳定可靠指标的下限较常规可靠度计算值偏小,这在重力坝坝基抗滑稳定分析中应引起重视。     

Telesurgery QoS improvement over SDN based on a Type‐2 fuzzy system and enhanced cuckoo optimization algorithm

Telemedicine is a new area based on the information and communication technology for collecting, storing, organizing, retrieving and exchanging medical information. One of the most important applications of telemedicine is indeed telesurgery in which an efficient telecommunication infrastructure between the surgery room and remote surgeons need to be established. One of the most important issues to be tackled in telesurgery is to find favorable links for routing as well as providing high Quality of Service (QoS). In this paper, an efficient model based on the hybridization of Type‐2 Fuzzy System (T2FS) and Cuckoo Optimization Algorithm (COA) over the Software Defined Networks (SDN) is proposed in order to achieve optimal and reliable routes for telesurgery application. Using T2FS, the fitness of the links is determined; then, a COA is conducted over the Constraint Shortest Path (CSP) problem to find the best routes. Delay is considered as a CSP problem which is satisfied by trying to find the paths with minimum cost. Due to the NP‐completeness of the CSP problem, an Enhanced COA (so‐called E‐COA) is proposed and utilized as a metaheuristic solver. To the best of our knowledge, this paper is the first SDN‐based communication model that applies both T2FS and E‐COA for assigning proper costs to the network's links, and solves the consequence CSP problem according to the QoS requirement for telesurgery. The model also recognizes and preserves the second‐best routes in order to keep the reliability for such a critical application. In addition to the simulations, the performance evaluation is also conducted on a real experimental scenario. Many comparisons are carried out between the proposed model and other conventional methods, and the evaluation study shows the superiority of the proposed model on all the three QoS‐related metrics, i.e. average end‐to‐end delay, packet loss ratio and PSNR.     

Modified transform-based gamma correction for MRI tumor image denoising and segmentation by optimized histon-based elephant herding algorithm

Medical image processing is typically performed to diagnose a patient's brain tumor prior to surgery. In this study, a technique in denoising and segmentation was developed to improve medical image processing. The proposed approach employs multiple modules. In the first module, the noisy brain tumor image is transformed into multiple low- and high-pass tetrolet coefficients. In the second module, multiple low-pass tetrolet coefficients are applied through a modified transform-based gamma correction method. Generalized cross-validation is used on multiple high-pass tetrolet coefficients to obtain the best threshold value. In the third module, all enhanced coefficients are applied to the partial differential equation method. In the final module, the denoised image is applied to Atanassov's intuitionistic fuzzy set histon-based fuzzy clustering method with centroid optimization using an elephant herding method. Accordingly, the tumor part is segmented from the nontumor part in the magnetic resonance imaging brain images. The method was assessed in terms of peak signal-to-noise ratio, mean square error, specificity, sensitivity, and accuracy. The experimental results showed that the suggested method is superior to traditional methods.