Filters
total: 241
Search results for: DIFFUSION MODELS
-
Asymptotic Expansion Method with Respect to Small Parameter for Ternary Diffusion Models
PublicationTernary diffusion models lead to strongly coupled systems of PDEs. We choose the smallest diffusion coefficient as a small parameter in a power series expansion whose components fulfill relatively simple equations. Although this series is divergent, one can use its finite sums to derive feasible numerical approximations, e.g. finite difference methods (FDMs).
-
Application of Diffusion Models in the Analysis of Financial Markets: Evidence on Exchange Traded Funds in Europe
PublicationExchange traded funds (ETFs) are financial innovations that may be considered as a part of the index financial instruments category, together with stock index derivatives. The aim of this paper is to explore the trajectories and formulates predictions regarding the spread of ETFs on the financial markets in six European countries. It demonstrates ETFs’ development trajectories with regard to stock index futures and options that...
-
Rothe’s method for physiologically structured models with diffusion
PublicationWe consider structured population models with diffusion and dynamic boundary conditions. The respective approximation, called Rothe’s method, produces positive and exponentially bounded solutions. Its solutions converge to the exact solution of the original PDE.
-
Method of lines for physiologically structured models with diffusion
PublicationWe deal with a size-structured model with diffusion. Partial differential equations are approximated by a large system of ordinary differential equations. Due to a maximum principle for this approximation method its solutions preserve positivity and boundedness. We formulate theorems on stability of the method of lines and provide suitable numerical experiments.
-
Diffusion process modeling by using fractional-order models
Publication -
Financial markets diffusion patterns. The case of Mexican investment funds
PublicationExchange traded funds (ETFs) are one of the most influential financial innovations, reshaping the investment funds market in many countries, including Mexico. Due to their similar investment objectives, ETFs are considered substitutes for mutual funds. The aim of the article is to provide an in-depth insight into the issues associated with the development of financial markets in Mexico...
-
New technologies and diffusion of innovative financial products: Evidence on exchange-traded funds in selected emerging and developed economies
PublicationExchange-traded funds (ETFs) are one of the most rapidly-expanding categories of innovative financial products that have been introduced on many financial markets, in both emerging and developed economies. Our research contributes to the present state of knowledge by examining factors, including information and communication technologies (ICTs), influencing the diffusion of ETFs. In our research, we consider also the impact of...
-
On possible applications of media described by fractional-order models in electromagnetic cloaking
PublicationThe purpose of this paper is to open a scientific discussion on possible applications of media described by fractional-order (FO) models (FOMs) in electromagnetic cloaking. A 2-D cloak based on active sources and the surface equivalence theorem is simulated. It employs a medium described by FOM in communication with sources cancelling the scattered field. A perfect electromagnetic active cloak is thereby demonstrated with the use...
-
Balance error generated by numerical diffusion in the solution of Muskingum equation
PublicationIn the paper the conservative properties of the lumped hydrological models with variable parameters are discussed. It is shown that in the case of the non-linear Muskingum equation the mass balance is not satisfied. The study indicates that the mass balance errors are caused by the improper form of equation and by the numerical diffusion which is generated in the solution. It has been shown that the classical way of derivation...
-
A compartment model of alveolar–capillary oxygen diffusion with ventilation–perfusion gradient and dynamics of air transport through the respiratory tract
PublicationThis paper presents a model of alveolar–capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differentia equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen transported into the human body are proposed as the connection between these models,...
-
Tracing financial innovation diffusion and substitution trajectories. Recent evidence on exchange-traded funds in Japan and South Korea.
PublicationSince the rapid growth of the popularity of ETFs, the potential substitution between innovative financial products, exchange-traded funds (ETFs), and traditional investment funds (open-end and closed-end funds) is recognized as one of the most-discussed issues in the financial industry. This is the first study to empirically verify and compare the diffusion and substitution of ETFs using monthly data on their assets in two selected...
-
Information and communication technologies versus diffusion and substitution of financial innovations. The case of exchange-traded funds in Japan and South Korea
PublicationThe substitution between financial innovations, exchange-traded funds (ETFs), and stock index derivatives (i.e. index financial instruments) is one of the relatively understudied topics of the financial sciences. The current study aims to verify empirically the diffusion and substitution of ETFs in the market for index financial instruments. It presents in-depth analysis of the development of index financial instruments traded...
-
Sustainable investing exchange-traded funds: US and European market
PublicationThe key aim of the paper is to examine the diffusion of the sustainable investing exchange-traded funds (ETFs) on the European and US ETFs markets, with the special focus on the market shares of sustainable investing and conventional funds. The model of diffusion of innovation (logistic growth model) is applied. Monthly data on the assets of ETFs in the time period of 2006-2017 are used. Increasing assets of sustainable investing...
-
Public Perception of Digital Contact Tracing App and Implications for Technology Acceptance and Use Models
PublicationGovernments are increasingly adopting digital contact tracing applications (DCT) as a key component of their response to the COVID-19 pandemic. However, governments are struggling to achieve widespread adoption of DCT necessary for obtaining the expected individual and public benefits associated with its use. Consequently, studies on DCT have focused on the barriers to DCT adoption in different contexts and possible ways of overcoming...
-
Nanosize effect of clay mineral nanoparticles on the drug diffusion processes in polyurethane nanocomposite hydrogels
PublicationStudies of swelling and release of naproxen sodium (NAP) solution by polyurethane nanocomposite hydrogels containing Cloisite® 30B (organically modified montmorillonite (OMMT)) have been performed. Polyurethane nanocomposite hydrogels are hybrid, nontoxic biomaterials with unique swelling and release properties in comparison with unmodified hydrogels. These features enable to use nanocomposite hydrogels as a modern wound dressing....
-
Reshaping financial systems: The role of ICT in the diffusion of financial innovations – Recent evidence from European countries
PublicationExchange-traded funds (ETFs) are among the fastest-growing types of innovative financial products. The emergence and spread of these instruments have been facilitated by the digital revolution. Information and communication technology (ICT) is profoundly reshaping the global economic landscape, laying solid foundations for unrestricted and unbounded flows of information and knowledge, eliminating information asymmetries, and furthering...
-
Nodal models of Pressurized Water Reactor core for control purposes – A comparison study
PublicationThe paper focuses on the presentation and comparison of basic nodal and expanded multi-nodal models of the Pressurized Water Reactor (PWR) core, which includes neutron kinetics, heat transfer between fuel and coolant, and internal and external reactivity feedback processes. In the expanded multi-nodal model, the authors introduce a novel approach to the implementation of thermal power distribution phenomena into the multi-node...
-
Exchange-Traded Funds in Europe
PublicationExchange-Traded Funds in Europe provides a single point of reference on a diverse set of regional ETF markets, illuminating the roles ETFs can play in risk mitigation and speculation. Combining empirical data with models and case studies, the authors use diffusion models and panel/country-specific regressions—as well as graphical and descriptive analyses— to show how ETFs are more than conventional, passive investments. With new...
-
Structural Adaptive, Self-Separating Material for Removing Ibuprofen from Waters and Sewage
Publication-cyclodextrin nanosponge (CDM) was used for the adsorption of ibuprofen (IBU) from water and sewage. The obtained material was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), Barrett– Joyner–Halenda (BJH), Harkins and Jura t-Plot, zeta potential, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elementary analysis (EA)....
-
Half-Order Modeling of Saturated Synchronous Machine
PublicationNoninteger order systems are used to model diffusion in conductive parts of electrical machines as they lead to more compact and knowledge models but also to improve their precision. In this paper a linear half-order impedance model of a ferromagnetic sheet deduced from the diffusion of magnetic field is briefly introduced. Then, from physical considerations and finite elements simulation, the nonlinear half-order impedance model...