scholarly journals Some insights into an integrative mathematical model: a prototype-model for bodyweight and energy homeostasis

2016 ◽  
Vol 7 (3) ◽  
pp. 1271
Author(s):  
Jorge Guerra Pires

The ambition of this document is to set in evidence the prerequisite for integrative (mathematical) models, mechanism-based models, for appetite/bodyweight control. For achieving this goal, it is provided a scrutinized literature review and it is organized them in such a way to make the point. The quantitative methods exploited by the authors are called differential equations solved numerically; they are discussed briefly since it is not our goal herein to handle details. On the current state of the art, there is no mathematical model to the best of the author’s knowledge targeting at integrating several hormones at once in mathematical descriptions: even for single hormones, the literature is either occasional or do not exist at all; it is depicted some results for simple models already built. As it can be seen, the functions and roles seem fuzzy, most hormones seem to be piloting the same undertaking. The key challenge from a mathematical modeling perspective is how to separate properly the mechanisms of each hormone. The kind of pursuit presented herein could initiate an imperative cascade of mathematical modeling applied to metabolism of bodyweight control and energy homeostasis.

2021 ◽  
Vol 10 (11) ◽  
pp. e449101119810
Author(s):  
Dhiego Henrique Ferreira Revoredo ◽  
Ana Cecília Vieira Nobrega ◽  
Arnaldo Manoel Pereira Carneiro ◽  
João Emanuell Araújo Marciano

Predictive mathematical models have been proposed in alkali-silica reaction (ASR). Predicting concrete degradation and its effects on mechanical properties is of interest given the long time until degradation becomes critical for intervention and recovery, and difficult structural access for predictive and corrective monitoring and treatment. The present paper presents a general overview of the evolution of the aforementioned predictive mathematical models, interrelating them to the maturation of the phenomenological state of the art associated with ASR.  For this purpose, a systematic literature review was used, followed by bibliometric analysis and meta-analysis. In this study, 104 articles from 1974 to 2020 were selected, of which 31 articles were reviewed on the topic of mathematical modeling of ASR. The results of the method indicated the importance of the methodological approach of literature review to provide a comprehensive and chronological view of the evolution of ASR consolidated in the literature. It was found that the mathematical models have evolved considering the phenomenological approach of ASR.


Author(s):  
И.А. Шаповалова

Современная иммунология не может успешно развиваться без помощи математического моделирования. Математические модели являются эффективным фильтром идей и индикатором правильности выбранных предположений, позволяют дать правильную интерпретацию результатам и выбирать критерии для оценки правильности, могут быть использованы как средство для визуализации результатов вычисления, что помогает дальнейшему развитию вычислительных алгоритмов. Исследование математической модели иммунной системы позволяет сравнивать теоретические и экспериментальные результаты и уточнять предположения, положенные в основу математического моделирования. Иммунная система является высокоразвитой биологической системой, функция которой заключается в выявлении и уничтожении чужеродного агента, поэтому она должна распознавать разнообразных возбудителей. Иммунная система способна к обучению, запоминанию, распознаванию образов, аналогичными свойствами обладают искусственные нейронные сети. Искусственные нейронные сети, подобно биологическим, являются вычислительной системой с огромным числом параллельно функционирующих простых процессоров с огромным числом связей. Нейросетевые алгоритмы используются в кластеризации, визуализации данных, контроле и оптимизации управляемых процессов, разработке искусственных нейронных сетей. В работе исследуется математическая модель иммунной системы, которая моделируется с помощью искусственной нейронной сети и описывается системой дифференциальных уравнений с запаздыванием. При анализе модели используется аппарат математической теории оптимального управления, а именно принцип максимума для систем дифференциальных уравнений с запаздыванием в аргументе функции состояния и аппарат методов оптимизации, базирующийся на методе быстрого автоматического дифференцирования. Вместо традиционных методов программирования используется обучение полносвязной искусственной нейронной сети с помощью метода распространения ошибки. Modern immunology can not be developed successfully without the help of mathematical modeling. Mathematical models are an effective way filter and indicator of the correctness of the selected assumptions. Mathematical models allow us to give a correct interpretation of the results, to select criteria for evaluating the correctness and that help the development of the numerical methods and algorithm. The research of the mathematical model of the immune system allow to compare theoretical and experimental results and clarified mathematical assumptions laid down in the basis of mathematical modeling. The immune system is a highly developed biological system, whose function is to detect and destroy foreign substance, so it needs to recognize a variety of pathogens.The immune system is capable of learning to remember the recognitions of images. The similar properties possess artificial neural networks. Similar to biological ones artificial neural networks are computer systems with a huge number of parallel functioning simple processors and with a large number of connections. Neural networks algorithms are used in clustering, data visualization, control and optimization of processes, the development of artificial neural networks. In the article we consider mathematical model of immune system modeled with the help of artificial multi layer neural net described by the system of differential equations with delay in argument of state functions. The model is analyzed with the help of the theory of optimal control namely the maximum principle of Pontrjagin for the systems of differential equations with delay in argument of the state functions. The method of optimization is based on the method of fast automatic differentiations. Instead of traditional methods of programming the training of the fully connected neural networks and the error propagation method are used.


2018 ◽  
Vol 8 (5) ◽  
pp. 529-546
Author(s):  
Christofer Laurell ◽  
Sten Soderman

PurposeThe purpose of this paper is to provide a systematic review of articles on sport published in leading business studies journals within marketing, organisational studies and strategy.Design/methodology/approachBased on a review of 38 identified articles within the subfields of marketing, strategy and organisation studies published between 2000 and 2015, the articles’ topical, theoretical and methodological orientation within the studied subfields were analysed followed by a cross-subfield analysis.FindingsThe authors identify considerable differences in topical, theoretical and methodological orientation among the studied subfields’ associated articles. Overall, the authors also find that articles across all subfields tend to be focussed on contributing to mature theory, even though the subfield of marketing in particular exhibits contributions to nascent theory in contrast to organisation studies and strategy.Originality/valueThis paper contributes by illustrating the current state of research that is devoted or related to the phenomenon of sport within three subfields in business studies. Furthermore, the authors discuss the role played by leading business studies journalsvis-à-vissport sector-specific journals and offer avenues for future research.


2016 ◽  
Vol 5 (S7) ◽  
pp. S1521-S1530 ◽  
Author(s):  
Thomas Wilhelm ◽  
Guoyang Wu ◽  
Afshin Teymoortash ◽  
Christian Güldner ◽  
Thomas Günzel ◽  
...  

Author(s):  
Nicklas Svendsen ◽  
Torben Anker Lenau

AbstractAs catalysts for product innovation and product development, different approaches for biologically inspired design (BID) are exciting options. However, while general BID theory require a focus on single functions, real world products are characterized by performing multiple functions. The development of an anterior eye-chamber model is used to showcase the issue.In a systematic literature review (SLR), state-of-the-art methodologies, methods and tools BID practice are discovered and the current state of multi-functionality in BID are assessed.The SLR revealed 18 contributions with 8 BID methodologies and 12 stage-specific BID tools (of which 50% addressed the solution search phase) in addition to 5 papers addressing multi-functionality in BID. At present multi-functionality in BID is only treated in a limited set of papers. While designers interested in BID are advised to discover multi-functional analogies, the present approach to handling multi-functional problems in BID suggest functional decomposition and multiple BID efforts. Therefore, the development of design support for handling multi-functional problems, including tools for problem analysis are needed.


Author(s):  
Albert C. J. Luo ◽  
Mohammad Dehghani ◽  
Hamid R. Hamidzadeh

Research on vibration of soils and foundations has yielded several fundamental methods for formulation of interaction problems. This paper is intended to survey the development of the current state-of-practice for design and analysis of dynamically loaded foundations. Extensive studies in this field utilize various linear mathematical models for interaction between foundations and different soil media. The effective analytical, numerical and experimental techniques and their methodologies which are well established for treating problems in dynamic soil-foundation interaction are outlined. Described techniques are categorized based upon formulation procedures and their applications. Some areas are indicated where further research is needed.


Author(s):  
David P. Nickerson ◽  
Martin L. Buist

In this era of widespread broadband Internet penetration and powerful Web browsers on most desktops, a shift in the publication paradigm for physiome-style models is envisaged. No longer will model authors simply submit an essentially textural description of the development and behaviour of their model. Rather, they will submit a complete working implementation of the model encoded and annotated according to the various standards adopted by the physiome project, accompanied by a traditional human-readable summary of the key scientific goals and outcomes of the work. While the final published, peer-reviewed article will look little different to the reader, in this new paradigm, both reviewers and readers will be able to interact with, use and extend the models in ways that are not currently possible. Here, we review recent developments that are laying the foundations for this new model publication paradigm. Initial developments have focused on the publication of mathematical models of cellular electrophysiology, using technology based on a CellML- or Systems Biology Markup Language (SBML)-encoded implementation of the mathematical models. Here, we review the current state of the art and what needs to be done before such a model publication becomes commonplace.


2000 ◽  
Vol 08 (04) ◽  
pp. 347-371 ◽  
Author(s):  
MINI GHOSH

In this paper, some nonlinear mathematical models are proposed and analyzed to study the spread of asthma due to inhaled pollutants from Industry. The following two types of demographics are considered here; (i) population with constant immigration, (ii) population with logistic growth. In each type of demography, the following three cases have been considered regarding the release of pollutant into the environment; (i) when emission of the pollutant into the environment is constant, (ii) when emission of the pollutant is population dependent, and (iii) when emission of the pollutant is periodic. Using stability theory of differential equations and computer simulation, it is shown that due to an increase in the air pollutant, the asthmatic (diseased) population increases in the region under consideration.


2021 ◽  
Vol 273 ◽  
pp. 08003
Author(s):  
Arthur Alukhanyan ◽  
Olga Panfilova

This work is devoted to development of economic and mathematical models for selection of the optimum investment solution. Moreover, it states the basis for development of model examples and correction of the model considering the results obtained in the examples. In the work the problem is set for selection of the investment sources and objects, which is limited to the linear programming problem. The controlled variable and basic limitations simulating real credit and monetary relations are distinguished in the provided model. The discounted profit obtained from implementation of the optimum investment portfolio is considered as a target function. The economic and mathematical model presented in the article allows finding the optimum investment solution within the limits of the credit and monetary relations taking place both at the micro- and macroeconomic level.


2021 ◽  
Vol 11 (24) ◽  
pp. 11811
Author(s):  
Christian Delgado-von-Eitzen ◽  
Luis Anido-Rifón ◽  
Manuel J. Fernández-Iglesias

Blockchain is one of the latest technologies attracting increasing attention from different actors in diverse fields, including the educational sector. The objective of this study is to offer an overview of the current state of the art related to blockchain in education that may serve as a reference for future initiatives in this field. For this, a systematic review of reference journals was carried out. Eleven databases were systematically searched and eligible papers that focused on blockchain in education that made significant contributions, and not only generic statements about the topic, were selected. As a result, 28 articles were analyzed. Lack of precision, and selection and analysis bias were then minimized by involving three researchers. The analysis of the selected papers provided invaluable insight and answered the research questions posed about the current state of the application of blockchain in education, about which of its characteristics can benefit this sector, and about the challenges that must be addressed. Blockchain may become a relevant technology in the educational field, and therefore many proofs of concept are being developed. However, there are still some relevant technological, regulatory and academic issues to be addressed to pave the way for the mainstream adoption of this technology.


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