The ANZIAM journal最新文献

METHODOLOGY AND CHALLENGES OF SURROGATE MODELLING METHODS FOR MULTI-FIDELITY EXPENSIVE BLACK-BOX PROBLEMS 多保真度昂贵黑箱问题的代用建模方法及其挑战

The ANZIAM journal Pub Date : 2024-05-31 DOI: 10.1017/s1446181124000087

NICOLAU ANDRÉS-THIÓ, MARIO ANDRÉS MUÑOZ, KATE SMITH-MILES

{"title":"METHODOLOGY AND CHALLENGES OF SURROGATE MODELLING METHODS FOR MULTI-FIDELITY EXPENSIVE BLACK-BOX PROBLEMS","authors":"NICOLAU ANDRÉS-THIÓ, MARIO ANDRÉS MUÑOZ, KATE SMITH-MILES","doi":"10.1017/s1446181124000087","DOIUrl":"https://doi.org/10.1017/s1446181124000087","url":null,"abstract":"Many industrial design problems are characterized by a lack of an analytical expression defining the relationship between design variables and chosen quality metrics. Evaluating the quality of new designs is therefore restricted to running a predetermined process such as physical testing of prototypes. When these processes carry a high cost, choosing how to gather further data can be very challenging, whether the end goal is to accurately predict the quality of future designs or to find an optimal design. In the multi-fidelity setting, one or more approximations of a design’s performance are available at varying costs and accuracies. Surrogate modelling methods have long been applied to problems of this type, combining data from multiple sources into a model which guides further sampling. Many challenges still exist; however, the foremost among them is choosing when and how to rely on available low-fidelity sources. This tutorial-style paper presents an introduction to the field of surrogate modelling for multi-fidelity expensive black-box problems, including classical approaches and open questions in the field. An illustrative example using Australian elevation data is provided to show the potential downfalls in blindly trusting or ignoring low-fidelity sources, a question that has recently gained much interest in the community.","PeriodicalId":74944,"journal":{"name":"The ANZIAM journal","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141197047","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

ELECTRO-OSMOTIC EFFECT ON PERISTALTIC FLOW OF PHAN–THIEN–TANNER FLUID IN A PLANAR CHANNEL 电渗对平面通道中范-天-丹纳流体蠕动流动的影响

The ANZIAM journal Pub Date : 2024-05-24 DOI: 10.1017/s1446181124000075

M. M. Channakote, SHEKAR M., V. K. Dilipkumar

{"title":"ELECTRO-OSMOTIC EFFECT ON PERISTALTIC FLOW OF PHAN–THIEN–TANNER FLUID IN A PLANAR CHANNEL","authors":"M. M. Channakote, SHEKAR M., V. K. Dilipkumar","doi":"10.1017/s1446181124000075","DOIUrl":"https://doi.org/10.1017/s1446181124000075","url":null,"abstract":"\u0000 There are several factors that can cause the excessive accumulation of biofluid in human tissue, such as pregnancy, local traumas, allergic responses or the use of certain therapeutic medications. This study aims to further investigate the shear-dependent peristaltic flow of Phan–Thien–Tanner (PTT) fluid within a planar channel by incorporating the phenomenon of electro-osmosis. This research is driven by the potential biomedical applications of this knowledge. The non-Newtonian fluid features of the PTT fluid model are considered as physiological fluid in a symmetric planar channel. This study is significant, as it demonstrates that the chyme in the small intestine can be modelled as a PTT fluid. The governing equations for the flow of the ionic liquid, thermal radiation and heat transfer, along with the Poisson–Boltzmann equation within the electrical double layer, are discussed. The long-wavelength (\u0000 \u0000 \u0000 \u0000$delta ll 1$\u0000\u0000 \u0000 ) and low-Reynolds-number approximations (\u0000 \u0000 \u0000 \u0000$Re to 0$\u0000\u0000 \u0000 ) are used to simplify the simultaneous equations. The solutions analyse the Debye electronic length parameter, Helmholtz–Smoluchowski velocity, Prandtl number and thermal radiation. Additionally, streamlines are used to examine the phenomenon of entrapment. Graphs are used to explain the influence of different parameters on the flow and temperature. The findings of the current model have practical implications in the design of microfluidic devices for different particle transport phenomena at the micro level. Additionally, the noteworthy results highlight the advantages of electro-osmosis in controlling both flow and heat transfer. Ultimately, our objective is to use these findings as a guide for the advancement of lab-on-a-chip systems.","PeriodicalId":74944,"journal":{"name":"The ANZIAM journal","volume":"7 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141099875","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

EXPONENTIAL ASYMPTOTICS USING NUMERICAL RATIONAL APPROXIMATION IN LINEAR DIFFERENTIAL EQUATIONS 线性微分方程中使用数值有理近似的指数渐近法

The ANZIAM journal Pub Date : 2024-04-22 DOI: 10.1017/s1446181124000038

CHRISTOPHER J. LUSTRI, SAMUEL CREW, S. JONATHAN CHAPMAN

{"title":"EXPONENTIAL ASYMPTOTICS USING NUMERICAL RATIONAL APPROXIMATION IN LINEAR DIFFERENTIAL EQUATIONS","authors":"CHRISTOPHER J. LUSTRI, SAMUEL CREW, S. JONATHAN CHAPMAN","doi":"10.1017/s1446181124000038","DOIUrl":"https://doi.org/10.1017/s1446181124000038","url":null,"abstract":"Singularly perturbed ordinary differential equations often exhibit Stokes’ phenomenon, which describes the appearance and disappearance of oscillating exponentially small terms across curves in the complex plane known as Stokes lines. These curves originate at singular points in the leading-order solution to the differential equation. In many important problems, it is impossible to obtain a closed-form expression for these leading-order solutions, and it is therefore challenging to locate these singular points. We present evidence that the analytic leading-order solution of a linear differential equation can be replaced with a numerical rational approximation using the adaptive Antoulas–Anderson (AAA) method. Despite such an approximation having completely different singularity types and locations, we show that the subsequent exponential asymptotic analysis accurately predicts the exponentially small behaviour present in the solution. For sufficiently small values of the asymptotic parameter, this approach breaks down; however, the range of validity may be extended by increasing the number of poles in the rational approximation. We present a related nonlinear problem and discuss the challenges that arise due to nonlinear effects. Overall, our approach allows for the study of exponentially small asymptotic effects without requiring an exact analytic form for the leading-order solution; this permits exponential asymptotic methods to be used in a much wider range of applications.","PeriodicalId":74944,"journal":{"name":"The ANZIAM journal","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140636905","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

FLUID INJECTION IN A POROUS MEDIUM: THE RADIAL SAFFMAN–TAYLOR INSTABILITY 多孔介质中的流体注入：径向萨夫曼-泰勒不稳定性

The ANZIAM journal Pub Date : 2024-04-19 DOI: 10.1017/s144618112400004x

SIENNA E. COOK, LARRY K. FORBES, STEPHEN J. WALTERS

引用次数: 0

DETECTING MOISTURE IN BAUXITE USING MICROWAVES 利用微波检测铝土矿中的水分

The ANZIAM journal Pub Date : 2024-04-17 DOI: 10.1017/s1446181124000026

LATA I. PAEA, SIONE PAEA, MARK J. MCGUINNESS

{"title":"DETECTING MOISTURE IN BAUXITE USING MICROWAVES","authors":"LATA I. PAEA, SIONE PAEA, MARK J. MCGUINNESS","doi":"10.1017/s1446181124000026","DOIUrl":"https://doi.org/10.1017/s1446181124000026","url":null,"abstract":"Mathematical modelling of microwaves travelling through bauxite ore provides a way to compute moisture content in the free space transmission method given data on signal attenuation, phase shift and variable bauxite depth. We extend a recently developed four-layer model that uses coupled ordinary differential wave equations for the electric field together with continuity boundary conditions at interfaces between ore, air and antenna to find a solution that incorporates multiple internal reflections in ore and air. The model provides good fits to data, depending on ore permittivity and conductivity. Our extensions are to use effective medium models to obtain electromagnetic properties of the ore mixture from moisture content and to incorporate the damping effects of scattering from the ore surface. Our model leads to a formula for the received signal showing how signal strengths SS and phase shifts depend on the moisture content of the bauxite ore, through the effects of moisture on permittivity and conductivity. We show that SS may be noninvertible, indicating that attenuation data alone cannot be used to infer moisture content. Combining with phase data typically corrects the noninvertibility. Reducing the operating frequency dramatically improves the usefulness of signal strength data for inferring moisture content.","PeriodicalId":74944,"journal":{"name":"The ANZIAM journal","volume":"2012 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140612337","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

OPTIMAL QUEUING STRATEGIES FOR AN M/G/1 RETRIAL QUEUE SYSTEM WITH RWV AND ISEV POLICIES 采用 rwv 和 isev 策略的 m/g/1 复审队列系统的最佳排队策略

The ANZIAM journal Pub Date : 2024-03-19 DOI: 10.1017/s1446181124000014

Z. CHEN, H. XU, H. HUO

{"title":"OPTIMAL QUEUING STRATEGIES FOR AN M/G/1 RETRIAL QUEUE SYSTEM WITH RWV AND ISEV POLICIES","authors":"Z. CHEN, H. XU, H. HUO","doi":"10.1017/s1446181124000014","DOIUrl":"https://doi.org/10.1017/s1446181124000014","url":null,"abstract":"Designing a reasonable M/G/1 retrial queue system that enhances service efficiency and reduces energy consumption is a challenging issue in Information and Communication Technology systems. This paper presents an M/G/1 retrial queue system incorporating random working vacation (RWV) and improved service efficiency during vacation (ISEV) policies, and examines its optimal queuing strategies. The RWV policy suggests that the server takes random working vacations during reserved idle periods, effectively reducing energy consumption. In contrast, the ISEV policy strives to augment service efficiency during regular working periods by updating, inspecting or maintaining the server on vacations. The system is transformed into a Cauchy problem to investigate its well-posedness and stability, employing operator semigroup theory. Based on the system’s stability, steady-state performance measures, such as service efficiency, energy consumption and expected costs, are quantified using the steady-state solution. The paper subsequently demonstrates the existence of optimal queuing strategies that achieve maximum efficiency and minimum expected costs. Finally, two numerical experiments are provided to illustrate the effectiveness of the system.","PeriodicalId":74944,"journal":{"name":"The ANZIAM journal","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140172706","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

ACTIVE REMODELLING OF TISSUES TO DESCRIBE BIPHASIC RHEOLOGICAL RESPONSES 用组织的主动重塑来描述双相流变反应

The ANZIAM journal Pub Date : 2024-02-26 DOI: 10.1017/s1446181123000226

DOMENIC P. J. GERMANO, STEPHANIE KHUU, ADRIANNE L. JENNER, JAMES M. OSBORNE, MARY R. MYERSCOUGH, MARK B. FLEGG

{"title":"ACTIVE REMODELLING OF TISSUES TO DESCRIBE BIPHASIC RHEOLOGICAL RESPONSES","authors":"DOMENIC P. J. GERMANO, STEPHANIE KHUU, ADRIANNE L. JENNER, JAMES M. OSBORNE, MARY R. MYERSCOUGH, MARK B. FLEGG","doi":"10.1017/s1446181123000226","DOIUrl":"https://doi.org/10.1017/s1446181123000226","url":null,"abstract":"<p>Tissues form from collections of cells that interact together mechanically via cell-to-cell adhesion, mediated by transmembrane cell adhesion molecules. Under a sufficiently large amount of induced stress, these tissues can undergo elastic deformation in the direction of tension, where they then elongate without any topological changes, and experience plastic deformation within the tissue. In this work, we present a novel mathematical model describing the deformation of cells, where tissues are elongated in a controlled manner. In doing so, the cells are able to undergo remodelling through elastic and then plastic deformation, in accordance with experimental observation. Our model describes bistable sizes of a cell that actively deform under stress to elongate the cell. In the absence of remodelling, the model reduces to the standard linear interaction model. In the presence of instant remodelling, we provide a bifurcation analysis to describe the existence of the bistable cell sizes. In the case of general remodelling, we show numerically that cells within a tissue may populate both the initial and elongated cell sizes, following a sufficiently large degree of stress.</p>","PeriodicalId":74944,"journal":{"name":"The ANZIAM journal","volume":"2014 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139968019","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

APPROXIMATE PRICING OF DERIVATIVES UNDER FRACTIONAL STOCHASTIC VOLATILITY MODEL 分数随机波动模型下衍生产品的近似定价

The ANZIAM journal Pub Date : 2024-01-15 DOI: 10.1017/s1446181123000202

Y. HAN, X. ZHENG

引用次数: 0

NONLINEAR SELF-MODULATION OF GRAVITY-CAPILLARY WAVES ON SHEAR CURRENTS IN FINITE DEPTH 有限深度剪切流上重力-毛细管波的非线性自调制

The ANZIAM journal Pub Date : 2024-01-12 DOI: 10.1017/s1446181123000196

TANMOY PAL, ASOKE KUMAR DHAR

引用次数: 0

ON MODELLING WATER QUALITY WITH STOCHASTIC DIFFERENTIAL EQUATIONS 用随机微分方程模拟水质

The ANZIAM journal Pub Date : 2024-01-09 DOI: 10.1017/s1446181123000214

MAHMOUD B. A. MANSOUR

引用次数: 0