computer simulation models
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Author(s):  
Hubert Sar ◽  
Mateusz Brukalski ◽  
Krzysztof Rokicki

Modelling of vehicle’s motion is one of the solutions applied in the research of automotive safety. There is always a discussion which model should be used for computer simulation. Models with higher number of degrees of freedom require identification of many parameters, which are usually difficult to obtain. So, very often relatively simple flat model of vehicle’s motion is applied. It needs only such parameters as mass of a vehicle, location of centre of gravity from front and rear axle, yaw mass moment of inertia and side slip characteristics of the front and rear axle. In this paper the upper mentioned model was applied, considering different side slip characteristics of the front and rear axle. The scenario of vehicle’s motion was based on random changes of steering wheel angle during the road test, recording signals from on-board CAN (Controller Area Network) bus of automobile simultaneously, which were further applied in simulation.


2021 ◽  
Vol 9 (4) ◽  
pp. 232596712199946
Author(s):  
Naomi Kobayashi ◽  
Shota Higashihira ◽  
Haruna Kitayama ◽  
Emi Kamono ◽  
Yohei Yukizawa ◽  
...  

Background: The influence of pelvic tilt mobility, which can be reproduced in computer-simulation models, is an important subject to be addressed in the understanding of femoroacetabular impingement (FAI) pathophysiology. Purpose: To use computer-simulation models of FAI cases to evaluate the optimum improvement in hip range of motion (ROM) achieved by decreasing the anterior pelvic tilt and compare the results with the improvement in ROM achieved after cam resection surgery. Study Design: Controlled laboratory study. Methods: The pre- and postoperative computed tomography (CT) images from 28 patients with FAI treated with arthroscopic cam resection were evaluated. Using a dynamic computer-simulation program, 3-dimensional models with a 5° and a 10° decrease in anterior pelvic tilt from the supine functional pelvic plane (baseline) were created from the preoperative CT scans. Similar models were constructed for hips before (at baseline) and after cam resection. Improvements from baseline in maximum internal rotation at 45°, 70°, and 90° of flexion were assessed for the 5° change in pelvic tilt, 10° change in pelvic tilt, and cam resection models, and the results were compared for all conditions. Results: The combination of a 10° change in pelvic tilt and cam resection showed the largest ROM improvement from baseline ( P < .001). Improvement in internal rotation in the cam resection model was significantly higher compared with the 5° pelvic tilt change model ( P < .001), while there was no significant difference between the cam resection model and the 10° pelvic tilt change model. Conclusion: Decreasing anterior pelvic tilt by 10° in the preoperative computer simulation model resulted in an equivalent effect to cam resection, while a 5° change in pelvic tilt was inferior to cam resection in terms of ROM improvement. Clinical Relevance: Enough of a decrease in anterior pelvic tilt may contribute to ROM improvement that is as effective as that of cam resection surgery.


ASJ. ◽  
2021 ◽  
Vol 1 (46) ◽  
pp. 40-48
Author(s):  
M. Lutfillaev ◽  
E. Abdullaev ◽  
F. Eshkobilov

This article examines the development of computer simulation models for laboratory work on the subject "Invertebrate Zoology". In particular, simulation models are shown for the following laboratory work: the external structure of the sponge, the accumulation of amoebocytes, the internal and external structure of the sponge, stinging cells, water circulation, the movement of the freshwater and longitudinal section of the hydra, the general view of the colony, the colony of the hydroid polyp in close-up, budding of jellyfish in blastostyle, parenchymula, planula, formed by a new colony.


Author(s):  
Pedro de Sousa Jr. ◽  
Simone Pereira ◽  
Ronaldo Rocha ◽  
Mateus Alves ◽  
Luciana Pinheiro ◽  
...  

The introduction of potentially toxic elements (PTEs) from industrial activities in water bodies, highlights the vulnerability of the environment and the need for actions focused on the implementation of mechanisms that help in the control and remediation of these impacts. The objective of the study was based on the integration of instrumental analytical methods, multivariate statistics, and computer simulation models, with the proposal of implementing realistic scenarios of the red mud plume behavior in the Pará River. The selected location was the municipality of Barcarena-PA, where is located an important alumina/aluminum industrial center. With the aid of the inductively coupled plasma optical emission spectrometer (ICP OES), the chemical elements Al, B, Cr, Fe, Mn, P, Ti, and Zn were quantified and the principal component analysis (PCA) allowed to select Al, B, Fe, P, and Zn as the most relevant with 98.68% of the accumulated variance. Some scenarios were proposed by the simulated hydrodynamic model, which evidenced that the Trambioca community would be the most affected in the first 13 h after the effluent overflowed, and the other locations in domino effect. The main scientific gain of the proposal is the possibility of the predictive scenarios to help the actions of containment and mitigation of environmental damages by public control agencies, institutions involved, and other competent bodies.


2021 ◽  
Vol 35 (1) ◽  
pp. 51-67
Author(s):  
Yashar Saghai

AbstractWill we, by 2050, be able to feed a rapidly growing population with healthy and sustainably grown food in a world threatened by systemic environmental crises? There are too many uncertainties for us to predict the long-term evolution of the global agri-food system, but we can explore a wide range of futures to inform policymaking and public debate on the future of food. This is typically done by creating scenarios (story lines that vividly describe what different futures could look like) and quantifying them with computer simulation models to get numerical estimates of how different aspects of the global agri-food system might evolve under different hypotheses. Among the many scenarios produced over the last twenty years, one would expect to see the future advocated by the food sovereignty movement, which claims to represent roughly two hundred million self-described “peasants” (small farmers) worldwide. This movement defends a vision of the future based on relocalized, sustainable, and just agri-food systems, self-governed through direct and participatory democratic processes. Yet, food sovereignty is conspicuously absent from quantified scenarios of global food futures. As part of the roundtable, “Ethics and the Future of the Global Food System,” this essay identifies seven obstacles that undermine the creation of food sovereignty scenarios by examining two attempts at crafting such scenarios.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6089
Author(s):  
X. Philip Ye ◽  
Shoujie Ren

Producing value-added chemicals from glycerol is imperative for the sustainable future of biodiesel. Despite worldwide efforts, the commercial production of acrylic acid from glycerol faces challenges, both technologically and economically. Based on our new technology using CO2 as a reaction medium in a two-step process to catalytically convert glycerol to acrylic acid, we established computer simulation models to analyze the energy efficiency and estimate production costs at different scenarios. The analysis was conducted in conjunction with published data of a typical, intermediate-sized biodiesel facility, aiming at the feasibility of producing acrylic acid on-site in the context of a circular economy. Variable analysis in response to the market value of glycerol, the source and cost of carbon dioxide recycling, and the changes in process scale and conditions are also presented. Results indicates that a cost-effective supply of CO2 to the acrylic acid plant is key to the further research and development.


2020 ◽  
Vol 117 (45) ◽  
pp. 27777-27785
Author(s):  
Edze R. Westra ◽  
Bruce R. Levin

Articles on CRISPR commonly open with some variant of the phrase “these short palindromic repeats and their associated endonucleases (Cas) are an adaptive immune system that exists to protect bacteria and archaea from viruses and infections with other mobile genetic elements.” There is an abundance of genomic data consistent with the hypothesis that CRISPR plays this role in natural populations of bacteria and archaea, and experimental demonstrations with a few species of bacteria and their phage and plasmids show that CRISPR-Cas systems can play this role in vitro. Not at all clear are the ubiquity, magnitude, and nature of the contribution of CRISPR-Cas systems to the ecology and evolution of natural populations of microbes and the strength of selection mediated by different types of phage and plasmids to the evolution and maintenance of CRISPR-Cas systems. In this perspective, with the aid of heuristic mathematical–computer simulation models, we explore the a priori conditions under which exposure to lytic and temperate phage and conjugative plasmids will select for and maintain CRISPR-Cas systems in populations of bacteria and archaea. We review the existing literature addressing these ecological and evolutionary questions and highlight the experimental and other evidence needed to fully understand the conditions responsible for the evolution and maintenance of CRISPR-Cas systems and the contribution of these systems to the ecology and evolution of bacteria, archaea, and the mobile genetic elements that infect them.


2020 ◽  
Vol 9 (2) ◽  
pp. 13-19 ◽  
Author(s):  
Amos Lal ◽  
Yuliya Pinevich ◽  
Ognjen Gajic ◽  
Vitaly Herasevich ◽  
Brian Pickering

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