{"title":"Fuzzy calculator – A tool for management needs","authors":"Simona Hašková, Petr Šuleř, Martin Smrt","doi":"10.1016/j.jocs.2024.102515","DOIUrl":"10.1016/j.jocs.2024.102515","url":null,"abstract":"<div><div>Fuzzy logic and fuzzy system models have become popular tools in the field of management as they enable efficient handling of uncertainty. We present a tool based on the authors´ original approach focused on solving complex managerial problems affected by the vagueness or uncertainty caused by the human factor. For this purpose, we show the connection between the functioning principle of the tool and processes occurring in the human mind including a description of its structure as perceived by an external observer. This is followed by an overview of selected fragments of fuzzy propositional logic, the theory of fuzzy sets, and the conclusions derived from it. The main part consists of formulating an algebraic description of the computational process of multi-criteria evaluation of the considered alternative performed by a fuzzy system, which serves as the executive unit of a Fuzzy calculator. This is supplemented by a flowchart diagram illustrating the algorithm of its functioning. The Fuzzy calculator distinguishes itself from other fuzzy systems by standardizing all linguistic variables, regardless of the number of linguistic values, into a unified framework comprising three terms <em>L</em>, <em>M</em>, and <em>H</em>, which are represented using trapezoidal fuzzy numbers, ensuring precise mathematical characterization. During the transformation, the original linguistic terms are preserved by incorporating the positions of their support intervals, thereby maintaining the specificity of the input information. This approach establishes the Fuzzy calculator as a universal and highly adaptable tool, capable of addressing a wide range of practical managerial problems with improved consistency and control.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102515"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Srati , A. Oulmelk , L. Afraites , A. Hadri , M.A. Zaky , A.S. Hendy
{"title":"On a computational paradigm for a class of fractional order direct and inverse problems in terms of physics-informed neural networks with the attention mechanism","authors":"M. Srati , A. Oulmelk , L. Afraites , A. Hadri , M.A. Zaky , A.S. Hendy","doi":"10.1016/j.jocs.2024.102514","DOIUrl":"10.1016/j.jocs.2024.102514","url":null,"abstract":"<div><div>Physics-Informed Neural Networks (PINNs) have recently gained significant attention for their ability to solve both forward and inverse problems associated with linear and nonlinear fractional partial differential equations (PDEs). However, PINNs, relying on feedforward neural networks (FNNs), overlook the crucial temporal dependencies inherent in practical physics systems. As a result, they fail to globally propagate the initial condition constraints and accurately capture the true solutions under various scenarios. In contrast, the attention mechanism offers flexible means to implicitly exploit patterns within inputs and, moreover, establish relationships between arbitrary query locations and inputs. Thus, we present an attention-based framework for PINNs, which we term PINNs-Transformer (Zhao et al., 2023). The framework was constructed using self-attention and a set of point-wise multilayer perceptrons (MLPs). The novelty is in applying the framework to the various fractional differential equations with stiff dynamics as well as their inverse formulations. We have also validated the PINNs-Transformer on two examples: one involving a fractional diffusion differential equation over time, and the other focused on identifying a space-dependent parameter associated with the direct problem described in the first example. We reinforce this finding by conducting a numerical comparison with variant of PINN methods based on criteria such as relative error, complexity, memory needs and execution time.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102514"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Onco*: An umbrella Python framework for modelling and simulation of oncological scenarios","authors":"Marlon Suditsch , Arndt Wagner , Tim Ricken","doi":"10.1016/j.jocs.2025.102533","DOIUrl":"10.1016/j.jocs.2025.102533","url":null,"abstract":"<div><div>The umbrella software Onco* provides a workflow for patient-specific tumour simulations. The general framework is exemplarily shown for brain tumours, where users are allowed to input medical image data or work with benchmark geometries. Three pre-processing Python packages generalise the magnetic resonance imaging series of the brain and segments the tumour and the heterogeneous microstructure of the tissue. The interpretation of collected information is followed by numerical simulations in a package, where users have the option to use pre-implemented model set-ups. These model set-ups can be customised, where each entity is editable, providing flexibility for ongoing development in the interdisciplinary field of tumour prediction. Two examples from a provided tutorial demonstrate the workflow and its capabilities from patient-specific and academic geometry input to potential tumour evolutions.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102533"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143335840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An efficient 6th-order compact difference scheme with error estimation for nonlocal Lane–Emden equation","authors":"Nirupam Sahoo, Randhir Singh","doi":"10.1016/j.jocs.2025.102529","DOIUrl":"10.1016/j.jocs.2025.102529","url":null,"abstract":"<div><div>In this manuscript, we present a new and efficient 6th-order compact difference method for solving the nonlocal Lane–Emden equation. This method effectively addresses singular-type problems without the need to modify or remove the singularities. To achieve this, we construct a uniform mesh across the domain and develop a new sixth-order discrete method that approximates the derivatives, transforming the differential equation into a system of equations. Use Newton or any iterative technique to obtain the numerical solution of the system of equations. Our new scheme efficiently handles the singularity at <span><math><mrow><mi>t</mi><mo>=</mo><mn>0</mn></mrow></math></span>. Additionally, we conduct a mathematical analysis of the method’s consistency, stability, error bounds, and convergence rate. We also include several numerical problems from the existing literature to demonstrate the accuracy, efficiency, and applicability of the proposed scheme. Also, compare the numerical approximations with the existing recent techniques. The newly proposed scheme offers 6th-order accuracy using a small-size matrix and delivers better numerical results than the existing methods.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102529"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jake Lever , Sibo Cheng , César Quilodrán Casas , Che Liu , Hongwei Fan , Robert Platt , Andrianirina Rakotoharisoa , Eleda Johnson , Siyi Li , Zhendan Shang , Rossella Arcucci
{"title":"Facing & mitigating common challenges when working with real-world data: The Data Learning Paradigm","authors":"Jake Lever , Sibo Cheng , César Quilodrán Casas , Che Liu , Hongwei Fan , Robert Platt , Andrianirina Rakotoharisoa , Eleda Johnson , Siyi Li , Zhendan Shang , Rossella Arcucci","doi":"10.1016/j.jocs.2024.102523","DOIUrl":"10.1016/j.jocs.2024.102523","url":null,"abstract":"<div><div>The rapid growth of data-driven applications is ubiquitous across virtually all scientific domains, and has led to an increasing demand for effective methods to handle data deficiencies and mitigate the effects of imperfect data. This paper presents a guide for researchers encountering real-world data-driven applications, and the respective challenges associated with this. This article proposes the concept of the Data Learning Paradigm, combining the principles of machine learning, data science and data assimilation to tackle real-world challenges in data-driven applications. Models are a product of the data upon which they are trained, and no data collected from real world scenarios is perfect due to natural limitations of sensing and collection. Thus, computational modelling of real world systems is intrinsically limited by the various deficiencies encountered in real data. The Data Learning Paradigm aims to leverage the strengths of data improvement to enhance the accuracy, reliability, and interpretability of data-driven models. We outline a range of methods which are currently being implemented in the field of Data Learning involving machine learning and data science methods, and discuss how these mitigate the various problems associated with data-driven models, illustrating improved results in a multitude of real world applications. We highlight examples where these methods have led to significant advancements in fields such as environmental monitoring, planetary exploration, healthcare analytics, linguistic analysis, social networks, and smart manufacturing. We offer a guide to how these methods may be implemented to deal with general types of limitations in data, alongside their current and potential applications.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102523"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaohui Su , Mingliang Zhang , Degao Zou , Yong Zhao , Jiantao Zhang , Haoyang Su
{"title":"Numerical scheme for solving the soil-water coupling problems based on finite volume method with unstructured mesh","authors":"Xiaohui Su , Mingliang Zhang , Degao Zou , Yong Zhao , Jiantao Zhang , Haoyang Su","doi":"10.1016/j.jocs.2025.102526","DOIUrl":"10.1016/j.jocs.2025.102526","url":null,"abstract":"<div><div>In this paper, a novel matrix-free finite volume (FV) numerical scheme with unstructured mesh is proposed for simulating unsaturated seepage-stress coupling problems in earth science. The proposed model solves Richards Equation (RE) for unsteady unsaturated infiltration flow and Cauchy Equation (CE) for soil dynamics. A universal finite volume (FV) numerical scheme is developed for solving the governing equations mentioned above with unstructured mesh. The techniques of matrix-free and fully implicit time stepping algorithm are utilized in the numerical discretization in order to avoiding for the calculation and storage of large matrices. The new model is assessed and evaluated by benchmarks and test infiltration cases. Comparing with the solutions of commercial software packages called GEO-Studio and AutoBANK, the accuracy of the proposed model is assessed and verified. A slope infiltration simulation case is carried out as the engineering application of the current model at last. With the advantage of novel numerical scheme and high accuracy, the proposed model shows its potential value in engineering application.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102526"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flow field analysis of Vortex Ring State through descent experiments and simulations with a quadcopter","authors":"Ryuki Mori , Ayato Takii , Masashi Yamakawa , Shinichi Asao , Seiichi Takeuchi , Yusei Kobayashi , Yongmann M. Chung","doi":"10.1016/j.jocs.2025.102528","DOIUrl":"10.1016/j.jocs.2025.102528","url":null,"abstract":"<div><div>Vortex Ring State (VRS), which can occur during descent of rotorcraft including drones, is a flow field phenomenon that causes instability and may result in a crash. In the Lecture Note, Mori (2024) focused on the rotor model of a quadcopter to analyze the flow field during VRS [1]. In this study which is an extension of that research, descent experiments using a quadcopter drone was conducted to collect flight data on the descent speed and attitude angle at which VRS can occur. As a result, large roll angle change was observed at descent speeds close to hovering induced velocity. Next, descent simulation using the same quadcopter model as in the descent experiment was conducted using the velocity data obtained in the real experiments to verify the flow field in the VRS. The numerical fluid dynamics simulations were performed by combining Moving Computational Domain (MCD) method and sliding mesh method, and by considering the coupling between the fluid and the rigid body. As a result, vortex ring was observed around the rotors when the descent velocity was close to the hovering induced velocity. From the Q criterion isosurface, it is considered that the flow including the disturbance generated by the rotors is stagnant around the rotors, which leads to the instability of the quadcopter. Furthermore, the lift value fluctuation rate of more than 15 % indicates that VRS was likely to have occurred at descent speeds close to the hovering induced speed.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102528"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diyi Liu , Weijie Du , Lin Lin , James P. Vary , Chao Yang
{"title":"An efficient quantum circuit for block encoding a pairing Hamiltonian","authors":"Diyi Liu , Weijie Du , Lin Lin , James P. Vary , Chao Yang","doi":"10.1016/j.jocs.2024.102480","DOIUrl":"10.1016/j.jocs.2024.102480","url":null,"abstract":"<div><div>We present an efficient quantum circuit for block encoding a pairing Hamiltonian often studied in nuclear physics. Our block encoding scheme does not require mapping the creation and annihilation operators to the Pauli operators and representing the Hamiltonian as a linear combination of unitaries. Instead, we show how to encode the Hamiltonian directly using controlled swap operations. We analyze the gate complexity of the block encoding circuit and show that it scales polynomially with respect to the number of qubits required to represent a quantum state associated with the pairing Hamiltonian. We also show how the block encoding circuit can be combined with the quantum singular value transformation to construct an efficient quantum circuit for approximating the density of states of a pairing Hamiltonian. The techniques presented can be extended to encode more general second-quantized Hamiltonians.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102480"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Integration of multi-fidelity methods in parametrized non-intrusive reduced order models for industrial applications","authors":"Fausto Dicech , Konstantinos Gkaragkounis , Lucia Parussini , Anna Spagnolo , Haysam Telib","doi":"10.1016/j.jocs.2024.102511","DOIUrl":"10.1016/j.jocs.2024.102511","url":null,"abstract":"<div><div>Exploring the behavior of complex industrial problems might become burdensome, especially in high-dimensional design spaces. Reduced Order Models (ROMs) aim to minimize the computational effort needed to study different design choices by exploiting already available data. In this work, we propose a methodology where the full-order solution is replaced with a Proper Orthogonal Decomposition based ROM, enhanced by a multi-fidelity surrogate model. Multi-fidelity approaches allow to exploit heterogeneous information sources, and consequently reduce the cost of creating the training data needed to build the ROM. To explore the multi-fidelity ROM capabilities, we present and discuss results and challenges for an automotive aerodynamic application, based on a geometric morphing of the DrivAer test case with multi-fidelity fluid-dynamics simulations.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102511"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A filling method for missing soft measurement data based on a conditional denoising diffusion model","authors":"Dongnian Jiang, Shuai Zhang","doi":"10.1016/j.jocs.2025.102531","DOIUrl":"10.1016/j.jocs.2025.102531","url":null,"abstract":"<div><div>In complex industrial processes, incomplete datasets are common due to problems such as different sampling periods and data loss, which reduces the accuracy of industrial soft sensing models. To solve this problem, this paper proposes a missing data generation and filling method based on a conditional denoising diffusion model. First, a missing area detection method based on a binary mark array is used to locate the region of missing data, and a masking mechanism is applied to obtain the accurate location and size of the missing data. Then, the correlation between the original data and the mask matrix is learned with a multi-head self-attention mechanism, and is used as the condition for the original denoising diffusion model to ensure the accuracy of the generated data. Finally, the generated data are filled into the missing areas to construct a complete dataset, with the aim of improving the prediction accuracy of the soft sensor model. The simulation results demonstrate that the proposed imputation method performs exceptionally well in filling missing data. Compared to traditional methods, it significantly enhances the prediction accuracy of the soft sensor model, reducing the mean squared error by approximately 40 %.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"85 ","pages":"Article 102531"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}