Search results for "Simulation."
showing 10 items of 4779 documents
The mechanism of aquaporin inhibition by gold compounds elucidated by biophysical and computational methods
2017
The inhibition of water and glycerol permeation via human aquaglyceroporin-3 (AQP3) by gold(iii) complexes has been studied by stopped-flow spectroscopy and, for the first time, its mechanism has been described using molecular dynamics (MD), combined with density functional theory (DFT) and electrochemical studies. The obtained MD results showed that the most effective gold-based inhibitor, anchored to Cys40 in AQP3, is able to induce shrinkage of pores preventing glycerol and water permeation. Moreover, the good correlation between the affinity of the Au(iii) complex to Cys binding and AQP3 inhibition effects was highlighted, while no influence of the different oxidative character of the c…
Usability Challenges in Surgical Simulator Training
2009
Surgical virtual reality simulators have been taken into use in order to improve surgical skills training. Emergence of simulators increases the need for research and knowledge related to usability of medical simulators. In this study usability of laparoscopic surgical simulator was researched experimentally through combined analysis. Data was gathered with heuristic evaluation, questionnaires, and interviews as well as recorded simulator parameters. Results suggest that the surgical simulator could be more efficient learning and training tool if usability issues such as support and error prevention were reconsidered in more detail. There also seem to be grounds for connecting user support …
Reshaping End-of-Life components by sheet hydroforming: An experimental and numerical analysis
2022
In this study, a numerical/experimental analysis is proposed to investigate the possibility of reshaping sheet metal-based End-of-Life (EoL) components using sheet Hydroforming (SHF). Returned EoL components are challenging to be reformed, they are usually characterised by high heterogeneity as there are localised thinning areas (caused by the original forming processes), and the overall formability is reduced with respect to the original flat sheet material. The reshaping route was replicated: a deep drawing process was adopted to impart a square feature; subsequently, SHF was performed. The capability of remove the deep drawn feature was analysed with varying Blank-holder force, oil press…
How can we apply the models of the quality of life and the quality of life management in an economy based on knowledge?
2017
The scientific substantiations of quality have been applied to models that pertain to mathematical statistics, the probability theory, the information theory, fuzzy systems, graphic methods, time series, and algebraic and numerical methods. To these, this article aims to present a new method of applying mathematical modelling in an economy based on knowledge, by using the concept of the definite integral, the composite function, and mathematical optimisation. The research methods used in the realisation of this article are bibliographic research, creation of new models, and problem-solving. Mathematical modelling, the simulation of the quality of life, etc. are methods and techniques of bot…
PRESCHOOL TEACHER’S ATTITUDE TO ENTERPRISE IN PRESCHOOL INSTITUTION
2014
Research on enterprise is known all over the Globe. Enterprise in education can serve as an opportunity for improving quality and effectiveness of education; it can be realized as added value. The Latvian National Development Plan shows that the education system task is to reach an educated man competitive labour market to develop people’s initiative, enterprise and creativity needed for the sustainable development of society. In the education sector is always an issue of how and whether the existing education system prepare new generation needs for adult life, pace of work and the changing environment etc. Question is: do we have preschool teachers who think and work in enterprise manner …
Can international environmental cooperation be bought?
2010
In this paper a two-stage game of international environmental agreement formation with asymmetric countries is analytically solved. The equilibrium of the game makes it possible to determine the size and composition of a stable agreement. Two cases are studied. In the first case, countries differ only in abatement costs, while in the second case, they differ in environmental damages. In both cases, two different institutional settings, one without transfers and another with transfers, are considered. The results establish that the asymmetry assumption has no important effects on the scope of cooperation in comparison with the symmetric case if transfers are not used or abatement costs repre…
Order allocation in a multiple suppliers-manufacturers environment within a dynamic cluster
2015
This study faces the problem of how to evaluate order allocation strategies in a multiple suppliers-manufacturers environment within a dynamic industry cluster that is an environment in which suppliers adopt a policy based on their performance to select the clusters in which to operate. Therefore, the allocation strategy performed by the manufacturers is crucial to keep a long-term supply chain partnership with a specific industry cluster. We use simulation to evaluate order allocation strategies under different market conditions. We show how an allocation strategy that takes into account the whole supply chain’s perspective leads to a sustainable development of the clusters of suppliers.
Analysis of discrete and continuous distributions of ventilatory time constants from dynamic computed tomography.
2005
In this study, an algorithm was developed to measure the distribution of pulmonary time constants (TCs) from dynamic computed tomography (CT) data sets during a sudden airway pressure step up. Simulations with synthetic data were performed to test the methodology as well as the influence of experimental noise. Furthermore the algorithm was applied to in vivo data. In five pigs sudden changes in airway pressure were imposed during dynamic CT acquisition in healthy lungs and in a saline lavage ARDS model. The fractional gas content in the imaged slice (FGC) was calculated by density measurements for each CT image. Temporal variations of the FGC were analysed assuming a model with a continuous…
Modeling and simulation of a digital control design approach for power supply systems
2006
Electronic designers need to model and simulate system features as close as possible to its effective behaviour. Moreover, today, electronics systems are often composed of mixed analog and digital components. The increasing complexity has led to the use of different simulation softwares, each one specific for a particular level of abstraction: mathematical, circuital, behavioural, etc. In order to simulate the entire system these softwares should work together: co-simulation is necessary for digitally controlled power electronics systems. In this paper, the modeling of a digitally controlled switching power supply system using MATLAB/Simulink, ALDEC Active-HDL and Powersys PSIM is presented…
Quantum Simulations of One-Dimensional Nanostructures under Arbitrary Deformations
2016
A powerful technique is introduced for simulating mechanical and electromechanical properties of one-dimensional nanostructures under arbitrary combinations of bending, twisting, and stretching. The technique is based on a novel control of periodic symmetry, which eliminates artifacts due to deformation constraints and quantum finite-size effects, and allows transparent electronic structure analysis. Via density-functional tight-binding implementation, the technique demonstrates its utility by predicting novel electromechanical properties in carbon nanotubes and abrupt behavior in the structural yielding of Au7 and MoS nanowires. The technique drives simulations markedly closer to the reali…