Journal of Computational Science最新文献

{"title":"BPMT: A hybrid model for secure and effective electronic medical record management system","authors":"Mehar Nasreen,&nbsp;Sunil Kumar Singh","doi":"10.1016/j.jocs.2024.102457","DOIUrl":"10.1016/j.jocs.2024.102457","url":null,"abstract":"<div><div>Designing an efficient distributed blockchain system to store and access rising electronic medical records (EMR) is still challenging. Although many techniques have been designed to utilize EMRs proficiently, they still suffer from accessing time, storage time, and throughput. In this work, we have proposed a Merkle and B+ tree-based hybrid model to improve the performance of the blockchain system. B+ tree has improved the system's performance because of its practical layout and balanced structure. At the same time, Merkle Tree has ensured the integrity and security of the information. The proposed (B+ Merkle tree) BPMT model has reduced the storage time of records, improved the system's throughput, and significantly reduced memory use. These enhancements are supported by a thorough complexity analysis and testing on several datasets, which validate the efficacy and scalability of the model. The outcomes validate the performance improvements of the model and lay the groundwork for further developments in blockchain-based EMR management.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102457"},"PeriodicalIF":3.1,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572829","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":"Enhanced heat transfer in ternary tangent hyperbolic nanofluids through non-darcy porous media","authors":"Lim Yeou Jiann ,&nbsp;Sharena Mohamad isa ,&nbsp;Noraihan Afiqah Rawi ,&nbsp;Sharidan Shafie ,&nbsp;Ahmad Qushairi Mohamad ,&nbsp;Dennis Ling Chaun Ching ,&nbsp;Nur Azlina Mat Noor","doi":"10.1016/j.jocs.2024.102462","DOIUrl":"10.1016/j.jocs.2024.102462","url":null,"abstract":"<div><div>The effectiveness of heat transfer fluids (HTFs) is pivotal in maximizing the efficiency and longevity of various devices, from small-scale applications to large industrial systems. A comprehensive understanding of the properties of innovative ternary heat transfer nanofluids (TNFs) is essential, particularly when utilized over a Darcy-Forchheimer porous medium. This study explores tangent hyperbolic thermal nanofluids (TNFs) made up of nanoparticles such as graphene, zirconium oxide and magnesium oxide and, suspended in an ethylene glycol base fluid, within a non-Darcy porous medium. Similarity variables are used to streamline the mathematical representation of fluid flow and heat transmission in TNFs. Then, semi-analytical solutions to the reduced governing equations are obtained using the homotopy analysis method. The influence of tri-nanoparticles, porosity, and the Forchheimer parameter on skin friction, fluid flow dynamics, heat transfer rates, and the Nusselt number is investigated. The Forchheimer parameter lowers the Nusselt number by 27.80 % for TNFs, 21.27 % for the hybrid nanofluid, and 21.08 % for the nanofluid. As a result, the temperature within TNFs is more evenly distributed. TNFs can transfer more heat by raising the medium’s porosity and the tri-nanoparticle volume fraction. These results unveil groundbreaking insights into enhancing the efficiency of heat transfer fluids. The introduction of a porous medium emerges as an alternate strategy to boost the performance of TNFs.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102462"},"PeriodicalIF":3.1,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553932","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":"Modeling and simulation of Fuzzy-rule based WBAN using multi-level fuzzy colored petri-nets and reinforcement learning","authors":"Negar Majma ,&nbsp;Seyed Morteza Babamir","doi":"10.1016/j.jocs.2024.102455","DOIUrl":"10.1016/j.jocs.2024.102455","url":null,"abstract":"<div><div>By developing IoTs (Internet of Things), a new concept is arising in WBANs (Wireless Body Area Networks), called IoBs (Internet of Bodies). WBANs are the safety-critical devices that use rule-based knowledge with fuzzy variables for monitoring patients. There are two issues with the knowledgebase: (1) appropriate knowledge representation and inference and (2) handling the situations for which there is no rule in the knowledgebase. In this paper, for the first issue we present MFCPN (Multi-level Fuzzy Colored Petri-nets) and for the second one we present a RL (Reinforcement Learning) mechanism for decision making based on the past device’s feedback to the environment. Through a few scenarios and two datasets, the proposed approach has been applied to pacemakers to show the approach's effectiveness. The comparison between decision making by our approach and two real datasets indicates the proposed approach has 79.3 % accuracy.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102455"},"PeriodicalIF":3.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531421","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":"Generative model-based framework for parameter estimation and uncertainty quantification applied to a compartmental model in epidemiology","authors":"Vinicius L.S. Silva ,&nbsp;Claire E. Heaney ,&nbsp;Nenko Nenov ,&nbsp;Christopher C. Pain","doi":"10.1016/j.jocs.2024.102451","DOIUrl":"10.1016/j.jocs.2024.102451","url":null,"abstract":"<div><div>We propose a new method in which a generative network (GN) set within a reduced-order model (ROM) framework is used to solve inverse problems for partial differential equations (PDE). The aim is to match available measurements and estimate the corresponding uncertainties associated with the states and parameters of a numerical physical simulation. We train the GN using only unconditional simulations of the discretized PDE model. A GN is used here to exploit the ability of these methods to generate realistic outputs from complex probability distributions, such as the ones that represent the possible states and parameters of a physical problem. We compare the proposed method with the gold standard Markov chain Monte Carlo (MCMC). Additionally, we suggest the use of a novel type of time-stepping regularization to improve the representativeness of the physical solution, and we present a new way of evaluating the GN training, taking advantage of the real/generated sample structure. We apply the proposed approaches to a spatio-temporal compartmental model in epidemiology. The results show that the proposed GN-based ROM can efficiently quantify uncertainty and accurately match the measurements and the gold standard. This is achieved using only a limited number of unconditional simulations from the full-order numerical PDE model (40 simulations). The GN-based ROM operates 60 times faster than the gold standard (MCMC), while producing uncertainties that closely match those generated by the MCMC approach. The proposed method is a general framework for quantifying uncertainties in numerical physical simulations and is not restricted to the specific physics of this application.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102451"},"PeriodicalIF":3.1,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531422","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":"On the theory of quantum and towards practical computation: A review","authors":"Robert Kudelić","doi":"10.1016/j.jocs.2024.102454","DOIUrl":"10.1016/j.jocs.2024.102454","url":null,"abstract":"<div><div>Quantum computing exposes the brilliance of quantum mechanics through computer science (in theory and otherwise), giving oneself a marvelous and exhilarating journey to go through. This review article leads along that journey with a historical and current outlook on quantum computation that is geared toward computer experts (via algorithmics) but also to experts from other disciplines as well. It is an article that will open an entering wedge through which one will be able to bring himself up to speed on quantum computation and challenges/limitations thereof. We are indeed in luck to be living in an age where computing is being reinvented, and not only seeing history in the making firsthand but, in fact, having the opportunity to be the ones who are reinventing—and that is quite a thought.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102454"},"PeriodicalIF":3.1,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445580","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":"A numerical framework for modeling evaporation and combustion of isolated, spherically-symmetric, multi-component fuel droplets","authors":"Alberto Cuoci ,&nbsp;Edoardo Cipriano ,&nbsp;Abd Essamade Saufi ,&nbsp;Alessio Frassoldati","doi":"10.1016/j.jocs.2024.102453","DOIUrl":"10.1016/j.jocs.2024.102453","url":null,"abstract":"<div><div>This paper presents a comprehensive numerical framework for simulating the evaporation and combustion of isolated, spherically-symmetric, multi-component fuel droplets. The framework incorporates a detailed description of chemical reactions in the gaseous phase and is capable of modeling pure evaporation, autoignition, and hot-wire ignition scenarios.</div><div>The transport equations for mass, species, and energy are solved in both the liquid (droplet) and gaseous (surrounding atmosphere) phases. Diffusion in the liquid phase is described using the Stefan–Maxwell theory, while in the gaseous phase, both molecular and thermal diffusion are considered. The model also includes the thermophoretic effect for carbonaceous particles and accounts for gas radiation through various models, ranging from optically-thin approximations to more complex methods like the P1 and discrete ordinate methods. Non-gray radiative effects are handled using the Weighted-Sum-of-Gray-Gases Model (WSGGM). Liquid/gas interface conditions are evaluated by imposing flux continuity of mass and energy, along with thermodynamic equilibrium for species. Deviations from ideal thermodynamic behavior in the liquid droplet are managed by incorporating a suitable activity coefficient or by using a proper cubic equation of state. Additionally, the presence of supporting fibers is modeled using a simplified one-dimensional approach. The transport equations are solved using the method of lines, with spatial discretization performed via the finite difference method on a body-fitted grid. The resulting system of Differential–Algebraic Equations (DAEs) is then solved using a fully-coupled approach.</div><div>Thanks to its generality in terms of kinetic and thermodynamic descriptions and the reduced computational time, the proposed framework offers significant potential for advancing our understanding of the complex combustion processes of multi-component liquid fuels and for enhancing the planning and execution of experiments involving isolated fuel droplets.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102453"},"PeriodicalIF":3.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433345","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":"Dynamic numerical calculation of multi-physics fields in IGBT chip layer based on ETM-PINN","authors":"Zhang Jiawei,&nbsp;Peng Hao,&nbsp;Han Wenxin,&nbsp;Yao Zhang,&nbsp;li Jueying,&nbsp;Min Yuan,&nbsp;Yuan yannan Mayu","doi":"10.1016/j.jocs.2024.102436","DOIUrl":"10.1016/j.jocs.2024.102436","url":null,"abstract":"<div><div>The electric-thermal-mechanical (ETM) multi-physics coupling fields commonly exists in power electronic devices such as insulate-gate bipolar transistor (IGBT), which dominates the evolution of key state variables inside the components. Among them, the junction e and electric potential of the chip layer, as the dependent variables of various lifetime physical models, directly affect its remaining service life and health status. Aiming at the problem that the key physical variables inside the IGBT are difficult to monitor and predict, this paper first integrates and establishes the ETM coupling partial differential equations (P<u>DEs</u>) inside the IGBT, then accordingly proposes an accurate numerical calculation method for coupled physical fields based on ETM-physics-informed neural networks (ETM-PINN).Through relevant simulation verification, it can not only realize the numerical calculation of the chip layer junction temperature and electric potential field without data, but also perform multi-physics predictive calculation with reduced accuracy in the absence of the key coefficients in PDEs. In the presence of additional physical field data, it can also perform data-model fusion calculations to further improve the solution accuracy.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102436"},"PeriodicalIF":3.1,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416164","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":"Sharkovskii’s theorem and the limits of digital computers for the simulation of chaotic dynamical systems","authors":"Peter V. Coveney","doi":"10.1016/j.jocs.2024.102449","DOIUrl":"10.1016/j.jocs.2024.102449","url":null,"abstract":"<div><div>Chaos is a unique paradigm in classical physics within which systems exhibit extreme sensitivity to the initial conditions. Thus, they need to be handled using probabilistic methods commonly based on ensembles. However, initial conditions generated by digital computers fall within the sparse set of discrete IEEE floating point numbers which have non-uniform distributions along the real axis. Therefore, there are many missing initial conditions whose absence might be expected to degrade the computed statistical properties of chaotic systems. The universality of this problem is enshrined in Sharkovskii’s theorem which is the simplest mathematical statement of the fact that no finite number representation of a chaotic dynamical system can account for all of its properties and shows that the precision of the representation limits the accuracy of the resulting digital behaviour.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102449"},"PeriodicalIF":3.1,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416161","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":"Bivariate Jacobi polynomials depending on four parameters and their effect on solutions of time-fractional Burgers’ equations","authors":"Khadijeh Sadri ,&nbsp;David Amilo ,&nbsp;Muhammad Farman ,&nbsp;Evren Hinçal","doi":"10.1016/j.jocs.2024.102450","DOIUrl":"10.1016/j.jocs.2024.102450","url":null,"abstract":"<div><div>The utilization of time-fractional Burgers’ equations is widespread, employed in modeling various phenomena such as heat conduction, acoustic wave propagation, gas turbulence, and the propagation of chaos in non-linear Markov processes. This study introduces a novel pseudo-operational collocation method, leveraging two-variable Jacobi polynomials. These polynomials are obtained through the Kronecker product of their one-variable counterparts, concerning both spatial (<span><math><mi>x</mi></math></span>) and temporal (<span><math><mi>t</mi></math></span>) domains. The study explores the impact of four parameters (<span><math><mrow><mi>θ</mi><mo>,</mo><mi>ϑ</mi><mo>,</mo><mi>σ</mi><mo>,</mo><mi>ς</mi><mo>&gt;</mo><mo>−</mo><mn>1</mn></mrow></math></span>) on the accuracy of resulting approximate solutions, marking the first examination of such influence. Collocation nodes in a tensor approach are constructed employing the roots of one-variable Jacobi polynomials of varying degrees in <span><math><mi>x</mi></math></span> and <span><math><mi>t</mi></math></span>. The study delves into analyzing how the distribution of these roots affects the outcomes. Consequently, pseudo-operational matrices are devised to integrate both integer and fractional orders, presenting a novel methodological advancement. By employing these matrices and appropriate approximations, the governing equations transform into an algebraic system, facilitating computational analysis. Furthermore, the existence and uniqueness of the equations under study are investigated and the study estimates error bounds within a Jacobi-weighted space for the obtained approximate solutions. Numerical simulations underscore the simplicity, applicability, and efficiency of the proposed matrix spectral scheme.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102450"},"PeriodicalIF":3.1,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416160","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":"Learnability of state spaces of physical systems is undecidable","authors":"Petr Spelda,&nbsp;Vit Stritecky","doi":"10.1016/j.jocs.2024.102452","DOIUrl":"10.1016/j.jocs.2024.102452","url":null,"abstract":"<div><div>Despite an increasing role of machine learning in science, there is a lack of results on limits of empirical exploration aided by machine learning. In this paper, we construct one such limit by proving undecidability of learnability of state spaces of physical systems. We characterize state spaces as binary hypothesis classes of the computable Probably Approximately Correct learning framework. This leads to identifying the first limit for learnability of state spaces in the agnostic setting. Further, using the fact that finiteness of the combinatorial dimension of hypothesis classes is undecidable, we derive undecidability for learnability of state spaces as well. Throughout the paper, we try to connect our formal results with modern neural networks. This allows us to bring the limits close to the current practice and make a first step in connecting scientific exploration aided by machine learning with results from learning theory.</div></div>","PeriodicalId":48907,"journal":{"name":"Journal of Computational Science","volume":"83 ","pages":"Article 102452"},"PeriodicalIF":3.1,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416152","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}