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A New Sine Family of Generalized Distributions: Statistical Inference with Applications 一个新的广义分布正弦族:统计推断及其应用
IF 1.9 Pub Date : 2023-07-16 DOI: 10.3390/mca28040083
SidAhmed Benchiha, L. Sapkota, Aned Al Mutairi, Vijay Kumar, Rana H. Khashab, Ahmed M. Gemeay, M. Elgarhy, S. G. Nassr
In this article, we extensively study a family of distributions using the trigonometric function. We add an extra parameter to the sine transformation family and name it the alpha-sine-G family of distributions. Some important functional forms and properties of the family are provided in a general form. A specific sub-model alpha-sine Weibull of this family is also introduced using the Weibull distribution as a parent distribution and studied deeply. The statistical properties of this new distribution are investigated and intended parameters are estimated using the maximum likelihood, maximum product of spacings, least square, weighted least square, and minimum distance methods. For further justification of these estimates, a simulation experiment is carried out. Two real data sets are analyzed to show the suggested model’s application. The suggested model performed well compares to some existing models considered in the study.
在本文中,我们使用三角函数广泛地研究了一类分布。我们给正弦变换族增加了一个额外的参数并把它命名为sin g分布族。族的一些重要的功能形式和性质以一般形式提供。并以威布尔分布为父分布,引入了该族的一个具体子模型-正弦威布尔,并对其进行了深入研究。研究了这种新分布的统计特性,并使用最大似然、最大间隔积、最小二乘、加权最小二乘和最小距离方法估计了预期参数。为了进一步证明这些估计,进行了模拟实验。通过对两个实际数据集的分析,说明了该模型的应用。与研究中考虑的一些现有模型相比,所提出的模型表现良好。
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引用次数: 2
Thermal Stress Formation in a Functionally Graded Al2O3-Adhesive Single Lap Joint Subjected to a Uniform Temperature Field 均匀温度场作用下功能梯度Al2O3胶粘剂单搭接接头的热应力形成
IF 1.9 Pub Date : 2023-07-11 DOI: 10.3390/mca28040082
M. Apalak, J. Reddy
This study investigates the strain and stress states in an aluminum single lap joint bonded with a functionally graded Al2O3 micro particle reinforced adhesive layer subjected to a uniform temperature field. Navier equations of elasticity theory were designated by considering the spatial derivatives of Lamé constants and the coefficient of thermal expansion for local material composition. The set of partial differential equations and mechanical boundary conditions for a two-dimensional model was reduced to a set of linear equations by means of the central finite difference approximation at each grid point of a discretized joint. The through-thickness Al2O3-adhesive composition was tailored by the functional grading concept, and the mechanical and thermal properties of local adhesive composition were predicted by Mori–Tanaka’s homogenization approach. The adherend–adhesive interfaces exhibited sharp discontinuous thermal stresses, whereas the discontinuous nature of thermal strains along bi-material interfaces can be moderated by the gradient power index, which controls the through-thickness variation of particle amount in the local adhesive composition. The free edges of the adhesive layer were also critical due to the occurrence of high normal and shear strains and stresses. The gradient power index can influence the distribution and levels of strain and stress components only for a sufficiently high volume fraction of particles. The grading direction of particles in the adhesive layer was not influential because the temperature field is uniform; namely, it can only upturn the low and high strain and stress regions so that the neat adhesive–adherend interface and the particle-rich adhesive–adherend interface can be relocated.
研究了均匀温度场作用下功能梯度Al2O3微颗粒增强粘结层粘结铝单搭接接头的应变和应力状态。考虑局部材料组成的lam常数和热膨胀系数的空间导数,给出了弹性理论的Navier方程。通过离散关节各网格点的中心有限差分逼近,将二维模型的偏微分方程和力学边界条件简化为线性方程组。采用功能分级概念对全厚度al2o3 -胶粘剂组合物进行了定制,并采用Mori-Tanaka的均质化方法预测了局部胶粘剂组合物的力学和热性能。黏着-黏着界面表现出明显的不连续热应力,而沿双材料界面的热应变的不连续性质可以通过梯度幂指数来缓和,梯度幂指数控制了局部黏着成分中颗粒量的穿过厚度变化。粘接层的自由边缘也很关键,因为发生了高的法向和剪切应变和应力。梯度功率指数只有在足够高的颗粒体积分数时才能影响应变和应力分量的分布和水平。由于温度场均匀,胶粘剂层内颗粒的级配方向不受影响;也就是说,它只能将低应变和高应变和应力区域向上翻转,从而使整洁的粘接界面和富含颗粒的粘接界面重新定位。
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引用次数: 0
Vehicle Make and Model Recognition as an Open-Set Recognition Problem and New Class Discovery 开集识别问题与新类发现
IF 1.9 Pub Date : 2023-07-03 DOI: 10.3390/mca28040080
Diana-Itzel Vázquez-Santiago, H. Acosta-Mesa, E. Mezura-Montes
One of the main limitations of traditional neural-network-based classifiers is the assumption that all query data are well represented within their training set. Unfortunately, in real-life scenarios, this is often not the case, and unknown class data may appear during testing, which drastically weakens the robustness of the algorithms. For this type of problem, open-set recognition (OSR) proposes a new approach where it is assumed that the world knowledge of algorithms is incomplete, so they must be prepared to detect and reject objects of unknown classes. However, the goal of this approach does not include the detection of new classes hidden within the rejected instances, which would be beneficial to increase the model’s knowledge and classification capability, even after training. This paper proposes an OSR strategy with an extension for new class discovery aimed at vehicle make and model recognition. We use a neuroevolution technique and the contrastive loss function to design a domain-specific CNN that generates a consistent distribution of feature vectors belonging to the same class within the embedded space in terms of cosine similarity, maintaining this behavior in unknown classes, which serves as the main guide for a probabilistic model and a clustering algorithm to simultaneously detect objects of new classes and discover their classes. The results show that the presented strategy works effectively to address the VMMR problem as an OSR problem and furthermore is able to simultaneously recognize the new classes hidden within the rejected objects. OSR is focused on demonstrating its effectiveness with benchmark databases that are not domain-specific. VMMR is focused on improving its classification accuracy; however, since it is a real-world recognition problem, it should have strategies to deal with unknown data, which has not been extensively addressed and, to the best of our knowledge, has never been considered from an OSR perspective, so this work also contributes as a benchmark for future domain-specific OSR.
传统的基于神经网络的分类器的主要局限性之一是假设所有查询数据在其训练集中都得到了很好的表示。不幸的是,在现实场景中,情况往往并非如此,在测试过程中可能会出现未知的类数据,这大大削弱了算法的鲁棒性。对于这类问题,开放集识别(OSR)提出了一种新的方法,该方法假设算法的世界知识是不完整的,因此它们必须准备好检测和拒绝未知类别的对象。然而,这种方法的目标不包括检测隐藏在被拒绝实例中的新类,这将有利于增加模型的知识和分类能力,即使在训练之后也是如此。本文提出了一种OSR策略,并扩展了针对车型和模型识别的新类发现。我们使用神经进化技术和对比损失函数设计了一个特定领域的CNN,该CNN根据余弦相似度在嵌入空间内生成属于同一类的特征向量的一致分布,并在未知类中保持这种行为,这作为概率模型和聚类算法的主要指导,以同时检测新类的对象并发现它们的类。结果表明,该策略能够有效地将VMMR问题作为OSR问题来解决,并且能够同时识别隐藏在被拒绝对象中的新类。OSR专注于展示它在非特定于领域的基准数据库中的有效性。VMMR致力于提高其分类精度;然而,由于它是一个现实世界的识别问题,它应该有策略来处理未知数据,这还没有得到广泛的解决,据我们所知,从来没有从OSR的角度考虑过,所以这项工作也有助于作为未来特定领域OSR的基准。
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引用次数: 0
Effect of Chrome and Vanadium on the Behavior of Hydrogen and Helium in Tungsten 铬和钒对钨中氢和氦行为的影响
IF 1.9 Pub Date : 2023-07-03 DOI: 10.3390/mca28040081
Meicong Li, Zheng Zhang, Yang Li, Qiang Zhao, Mei Huang, Xiaoping Ouyang
Tungsten is a promising material for nuclear fusion reactors, but its performance can be degraded by the accumulation of hydrogen (H) and helium (He) isotopes produced by nuclear reactions. This study investigates the effect of chrome (Cr) and vanadium (V) on the behavior of hydrogen and helium in tungsten (W) using first-principles calculations. The results show W becomes easier to process after adding Cr and V. Stability improves after adding V. Adding Cr negatively impacts H and He diffusion in W, while V promotes it. There is attraction between H and Cr or H and V for distances over 1.769 Å but repulsion below 1.583 Å. There is always attraction between He and Cr or V. The attraction between vacancies and He is stronger than that between He and Cr or V. There is no clear effect on H when vacancies and Cr or V coexist in W. Vacancies can dilute the effects of Cr and V on H and He in W.
钨是一种很有前途的核聚变反应堆材料,但其性能可能会因核反应产生的氢(H)和氦(He)同位素的积累而降低。本研究利用第一性原理计算研究了铬(Cr)和钒(V)对钨(W)中氢和氦行为的影响。结果表明,添加Cr和V后,W变得更容易加工。添加V后,稳定性提高。添加Cr对H和He在W中的扩散产生负面影响,而V促进了扩散。在1.769Å以上的距离内,H和Cr或H和V之间存在吸引,但在1.583Å以下存在排斥。He与Cr或V之间总是存在吸引力。空位与He之间的吸引力强于He与Cr或V之间的吸引力。当W中空位与Cr或V共存时,对H没有明显的影响。空位可以稀释Cr和V对W中H和He的影响。
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引用次数: 0
A New Method for Improving Inverse Finite Element Method Material Characterization for the Mooney–Rivlin Material Model through Constrained Optimization 基于约束优化的Mooney-Rivlin材料模型反演有限元表征新方法
IF 1.9 Pub Date : 2023-06-24 DOI: 10.3390/mca28040078
J. V. Van Tonder, M. Venter, G. Venter
The inverse finite element method is a technique that can be used for material model parameter characterization. The literature shows that this approach may get caught in the local minima of the design space. These local minimum solutions often fit the material test data with small errors and are often mistaken for the optimal solution. The problem with these sub-optimal solutions becomes apparent when applied to different loading conditions where significant errors can be witnessed. The research of this paper presents a new method that resolves this issue for Mooney–Rivlin and builds on a previous paper that used flat planes, referred to as hyperplanes, to map the error functions, isolating the unique optimal solution. The new method alternatively uses a constrained optimization approach, utilizing equality constraints to evaluate the error functions. As a result, the design space’s curvature is taken into account, which significantly reduces the amount of variation between predicted parameters from a maximum of 1.934% in the previous paper down to 0.1882% in the results presented here. The results of this study demonstrate that the new method not only isolates the unique optimal solution but also drastically reduces the variation in the predicted parameters. The paper concludes that the presented new characterization method significantly contributes to the existing literature.
逆有限元法是一种可以用于材料模型参数表征的技术。文献表明,这种方法可能会陷入设计空间的局部极小值中。这些局部最小解通常以较小的误差拟合材料试验数据,并且经常被误认为是最优解。当应用于不同的加载条件时,这些次优解的问题变得明显,在这些条件下可以看到显著的误差。本文的研究为Mooney–Rivlin提出了一种解决这一问题的新方法,并建立在之前的一篇论文的基础上,该论文使用被称为超平面的平面来映射误差函数,从而分离出唯一的最优解。新方法可替代地使用约束优化方法,利用等式约束来评估误差函数。因此,考虑了设计空间的曲率,这大大减少了预测参数之间的变化量,从上一篇论文中的最大值1.934%下降到这里给出的结果中的0.1882%。这项研究的结果表明,新方法不仅分离出唯一的最优解,而且大大减少了预测参数的变化。本文的结论是,所提出的新的表征方法对现有文献做出了重大贡献。
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引用次数: 0
Solve High-Dimensional Reflected Partial Differential Equations by Neural Network Method 用神经网络方法求解高维反射偏微分方程
IF 1.9 Pub Date : 2023-06-24 DOI: 10.3390/mca28040079
Xiaowen Shi, Xiangyu Zhang, Renwu Tang, Juan Yang
Reflected partial differential equations (PDEs) have important applications in financial mathematics, stochastic control, physics, and engineering. This paper aims to present a numerical method for solving high-dimensional reflected PDEs. In fact, overcoming the “dimensional curse” and approximating the reflection term are challenges. Some numerical algorithms based on neural networks developed recently fail in solving high-dimensional reflected PDEs. To solve these problems, firstly, the reflected PDEs are transformed into reflected backward stochastic differential equations (BSDEs) using the reflected Feyman–Kac formula. Secondly, the reflection term of the reflected BSDEs is approximated using the penalization method. Next, the BSDEs are discretized using a strategy that combines Euler and Crank–Nicolson schemes. Finally, a deep neural network model is employed to simulate the solution of the BSDEs. The effectiveness of the proposed method is tested by two numerical experiments, and the model shows high stability and accuracy in solving reflected PDEs of up to 100 dimensions.
反射偏微分方程在金融数学、随机控制、物理学和工程中有着重要的应用。本文旨在提出一种求解高维反射偏微分方程的数值方法。事实上,克服“维度诅咒”和近似反射项是一项挑战。最近开发的一些基于神经网络的数值算法在求解高维反射偏微分方程方面失败了。为了解决这些问题,首先,使用反射的Feyman–Kac公式将反射的偏微分方程转换为反射的后向随机微分方程。其次,使用惩罚方法对反射的BSDE的反射项进行近似。接下来,使用结合Euler和Crank–Nicolson方案的策略对BSDE进行离散化。最后,采用深度神经网络模型对BSDE的求解进行了仿真。通过两个数值实验验证了该方法的有效性,该模型在求解高达100维的反射偏微分方程时显示出较高的稳定性和准确性。
{"title":"Solve High-Dimensional Reflected Partial Differential Equations by Neural Network Method","authors":"Xiaowen Shi, Xiangyu Zhang, Renwu Tang, Juan Yang","doi":"10.3390/mca28040079","DOIUrl":"https://doi.org/10.3390/mca28040079","url":null,"abstract":"Reflected partial differential equations (PDEs) have important applications in financial mathematics, stochastic control, physics, and engineering. This paper aims to present a numerical method for solving high-dimensional reflected PDEs. In fact, overcoming the “dimensional curse” and approximating the reflection term are challenges. Some numerical algorithms based on neural networks developed recently fail in solving high-dimensional reflected PDEs. To solve these problems, firstly, the reflected PDEs are transformed into reflected backward stochastic differential equations (BSDEs) using the reflected Feyman–Kac formula. Secondly, the reflection term of the reflected BSDEs is approximated using the penalization method. Next, the BSDEs are discretized using a strategy that combines Euler and Crank–Nicolson schemes. Finally, a deep neural network model is employed to simulate the solution of the BSDEs. The effectiveness of the proposed method is tested by two numerical experiments, and the model shows high stability and accuracy in solving reflected PDEs of up to 100 dimensions.","PeriodicalId":53224,"journal":{"name":"Mathematical & Computational Applications","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46800597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Inducing Perceptual Dominance with Binocular Rivalry in a Virtual Reality Head-Mounted Display 虚拟现实头戴式显示器双目竞争诱导知觉优势
IF 1.9 Pub Date : 2023-06-17 DOI: 10.3390/mca28030077
Julianne Blignaut, Martin Venter, D.J. van den Heever, M. Solms, Ivan Crockart
Binocular rivalry is the perceptual dominance of one visual stimulus over another. Conventionally, binocular rivalry is induced using a mirror-stereoscope—a setup involving mirrors oriented at an angle to a display. The respective mirror planes fuse competing visual stimuli in the observer’s visual field by projecting the stimuli through the stereoscope to the observed visual field. Since virtual-reality head-mounted displays fuse dichoptic vision in a similar way, and since virtual-reality head-mounted displays are more versatile and more readily available than mirror stereoscopes, this study investigated the efficacy of using a virtual-reality headset (Oculus Rift-S) as an alternative to using a mirror stereoscope to study binocular rivalry. To evaluate the validity of using virtual-reality headsets to induce visual dominance/suppression, two identical experimental sequences—one using a conventional mirror stereoscope and one using a virtual-reality headset—were compared and evaluated. The study used Gabor patches at different orientations to induce binocular rivalry and to evaluate the efficacy of the two experiments. Participants were asked to record all instances of perceptual dominance (complete suppression) and non-dominance (incomplete suppression). Independent sample t-tests confirmed that binocular rivalry with stable vergence was successfully induced for the mirror-stereoscope experiment (t = −4.86; p ≤ 0.0001) and the virtual-reality experiment (t = −9.41; p ≤ 0.0001). Using ANOVA to compare Gabor patch pairs of gratings at +45°/−45° orientations presented in both visual fields, gratings at 0°/90° orientations presented in both visual fields, and mixed gratings (i.e., unconventional grating pairs) presented in both visual fields, the performance of the two experiments was evaluated by comparing observation duration in seconds (F = 0.12; p = 0.91) and the alternation rate per trial (F = 8.1; p = 0.0005). The differences between the stimulus groups were not statistically significant for the observation duration but were significantly different based on the alternation rates per trial. Moreover, ANOVA also showed that the dominance durations (F = 114.1; p < 0.0001) and the alternation rates (F = 91.6; p < 0.0001) per trial were significantly different between the mirror-stereoscope and the virtual-reality experiments, with the virtual-reality experiment showing an increase in alternation rate and a decrease in observation duration. The study was able to show that a virtual-reality head-mounted display can be used as an effective and novel alternative to induce binocular rivalry, but there were some differences in visual bi-stability between the two methods. This paper discusses the experimental measures taken to minimise piecemeal rivalry and to evaluate perceptual dominance between the two experimental designs.
双眼竞争是一种视觉刺激对另一种视觉激励的感知优势。传统上,双目竞争是使用镜面立体镜来诱导的,这种设置包括与显示器成一定角度的镜子。各个镜平面通过将刺激通过立体镜投射到观察到的视野来融合观察者视野中的竞争性视觉刺激。由于虚拟现实头戴式显示器以类似的方式融合了二视视觉,并且虚拟现实头戴式显示器比镜面立体镜更通用、更容易获得,本研究调查了使用虚拟现实耳机(Oculus Rift-S)作为使用镜面立体镜的替代品来研究双眼竞争的效果。为了评估使用虚拟现实耳机诱导视觉优势/抑制的有效性,对两个相同的实验序列——一个使用传统的镜面立体镜,另一个使用虚拟现实头戴式耳机——进行了比较和评估。该研究使用不同方向的Gabor贴片来诱导双眼竞争,并评估两个实验的疗效。参与者被要求记录感知支配(完全抑制)和非支配(不完全抑制)的所有情况。独立样本t检验证实,镜面立体镜实验(t=−4.86;p≤0.0001)和虚拟现实实验(t=−9.41;p≤.0001)成功诱导了具有稳定收敛性的双眼竞争。使用ANOVA比较两个视野中+45°/-45°方向的Gabor补片光栅对,在两个视野中呈现的0°/90°取向的光栅,以及在两个视场中呈现的混合光栅(即非常规光栅对),通过比较以秒为单位的观察持续时间(F=0.12;p=0.91)和每次试验的交替率(F=8.1;p=0.0005)来评估两个实验的性能。刺激组之间的差异在观察持续时间方面没有统计学意义,但在每次试验的变化率基础上有显著差异。此外,方差分析还显示,在镜像立体镜和虚拟现实实验之间,每次试验的优势持续时间(F=141.1;p<0.0001)和交替率(F=91.6;p<0.001)显著不同,虚拟现实实验显示交替率增加,观察持续时间减少。这项研究表明,虚拟现实头戴式显示器可以作为一种有效而新颖的替代品来诱导双眼竞争,但这两种方法在视觉双稳定性方面存在一些差异。本文讨论了为尽量减少零碎竞争而采取的实验措施,并评估了两种实验设计之间的感知优势。
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引用次数: 0
Developing a Robust Bioventing Model 开发一个稳健的生物通气模型
IF 1.9 Pub Date : 2023-06-16 DOI: 10.3390/mca28030076
Mohammad Khodabakhshi Soureshjani, R. Zytner
Bioventing is a widely recognized technique for the remediation of petroleum hydrocarbon-contaminated soil. In this study, the objective was to identify an optimal mathematical model that balances accuracy and ease of implementation. A comprehensive review of various models developed for bioventing was conducted wherein the advantages and disadvantages of each model were evaluated and compared regarding the different numerical methods used to solve relevant bioventing equations. After investigating the various assumptions and methods from the literature, an improved foundational bioventing model was developed that characterizes gas flow in unsaturated zones where water and non-aqueous phase liquid (NAPL) are present and immobile, accounting for interphase mass transfer and biodegradation, incorporating soil properties through a rate constant correlation. The proposed model was solved using the finite volume method in OpenFOAM, an independent dimensional open-source coding toolbox. The preliminary simulation results of a simple case indicate good agreement with the exact analytical solution of the same equations. This improved bioventing model has the potential to enhance predictions of the remediation process and support the development of efficient remediation strategies for petroleum hydrocarbon-contaminated soil.
生物通气是一种公认的修复石油碳氢化合物污染土壤的技术。在这项研究中,目的是确定一个平衡准确性和易用性的最佳数学模型。对为生物通气开发的各种模型进行了全面审查,其中评估并比较了每个模型的优缺点,以及用于求解相关生物通气方程的不同数值方法。在研究了文献中的各种假设和方法后,开发了一个改进的基础生物通气模型,该模型表征了水和非水相液体(NAPL)存在且不动的不饱和带中的气体流动,考虑了相间传质和生物降解,并通过速率常数相关性结合了土壤特性。所提出的模型是使用OpenFOAM中的有限体积方法求解的,OpenFOAM是一个独立的维度开源编码工具箱。一个简单情况的初步模拟结果表明,与同一方程的精确解析解吻合良好。这种改进的生物通气模型有可能增强对修复过程的预测,并支持开发有效的石油烃污染土壤修复策略。
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引用次数: 0
Evolutionary Selection of a Set of Association Rules Considering Biological Constraints Describing the Prevalent Elements in Bacterial Vaginosis 考虑描述细菌性阴道病流行因素的生物学约束的一组关联规则的进化选择
IF 1.9 Pub Date : 2023-06-14 DOI: 10.3390/mca28030075
María Concepción Salvador-González, Juana Canul-Reich, Rafael Rivera-López, E. Mezura-Montes, E. de la cruz-Hernandez
Bacterial Vaginosis is a common disease and recurring public health problem. Additionally, this infection can trigger other sexually transmitted diseases. In the medical field, not all possible combinations among the pathogens of a possible case of Bacterial Vaginosis are known to allow a diagnosis at the onset of the disease. It is important to contribute to this line of research, so this study uses a dataset with information from sexually active women between 18 and 50 years old, including 17 numerical attributes of microorganisms and bacteria with positive and negative results for BV. These values were semantically categorized for the Apriori algorithm to create the association rules, using support, confidence, and lift as statistical metrics to evaluate the quality of the rules, and incorporate those results in the objective function of the DE algorithm. To guide the evolutionary process we also incorporated the knowledge of a human expert represented as a set of biologically meaningful constraints. Thus, we were able to compare the performance of the rand/1/bin and best/1/bin versions from Differential Evolution to analyze the results of 30 independent executions. Therefore the experimental results allowed a reduced subset of biologically meaningful association rules by their executions, dimension, and DE version to be selected.
细菌性阴道病是一种常见的疾病,也是反复出现的公共卫生问题。此外,这种感染还会引发其他性传播疾病。在医学领域,并非所有可能的细菌性阴道病病原体组合都能在疾病发作时进行诊断。为这一研究领域做出贡献是很重要的,因此本研究使用了一个数据集,该数据集包含18至50岁性活跃女性的信息,包括微生物和细菌的17个数字属性,BV的阳性和阴性结果。Apriori算法对这些值进行了语义分类,以创建关联规则,和lift作为统计度量来评估规则的质量,并将这些结果纳入DE算法的目标函数中。为了指导进化过程,我们还引入了一位人类专家的知识,该知识被表示为一组具有生物学意义的约束。因此,我们能够比较差分进化的rand/1/bin和best/1/bin版本的性能,以分析30个独立执行的结果。因此,实验结果允许通过执行、维度和DE版本来选择具有生物学意义的关联规则的缩减子集。
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引用次数: 0
Convexity-Preserving Rational Cubic Zipper Fractal Interpolation Curves and Surfaces 保凸有理三次Zipper分形插值曲线和曲面
IF 1.9 Pub Date : 2023-06-10 DOI: 10.3390/mca28030074
Vijay, A. Chand
A class of zipper fractal functions is more versatile than corresponding classes of traditional and fractal interpolants due to a binary vector called a signature. A zipper fractal function constructed through a zipper iterated function system (IFS) allows one to use negative and positive horizontal scalings. In contrast, a fractal function constructed with an IFS uses positive horizontal scalings only. This article introduces some novel classes of continuously differentiable convexity-preserving zipper fractal interpolation curves and surfaces. First, we construct zipper fractal interpolation curves for the given univariate Hermite interpolation data. Then, we generate zipper fractal interpolation surfaces over a rectangular grid without using any additional knots. These surface interpolants converge uniformly to a continuously differentiable bivariate data-generating function. For a given Hermite bivariate dataset and a fixed choice of scaling and shape parameters, one can obtain a wide variety of zipper fractal surfaces by varying signature vectors in both the x direction and y direction. Some numerical illustrations are given to verify the theoretical convexity results.
由于一种称为签名的二进制矢量,一类拉链分形函数比相应的传统和分形插值类更通用。通过拉链迭代函数系统(IFS)构建的拉链分形函数允许使用负和正水平尺度。相反,用IFS构造的分形函数只使用正的水平尺度。本文介绍了几类新的连续可微保凸拉链分形插值曲线和曲面。首先,我们为给定的单变量Hermite插值数据构造拉链分形插值曲线。然后,我们在不使用任何额外节点的情况下,在矩形网格上生成拉链分形插值曲面。这些曲面插值一致收敛于一个连续可微的二元数据生成函数。对于给定的Hermite二元数据集和固定的缩放和形状参数选择,可以通过在x方向和y方向上改变特征向量来获得各种各样的拉链分形表面。给出了一些数值例子来验证理论上的凸性结果。
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引用次数: 0
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