Comparative analysis of lower limbs muscles effort during standing-sitting motion by musculoskeletal mathematical model

2016 ◽  
Vol 2016 (0) ◽  
pp. B-2
Author(s):  
Yuya ONODERA ◽  
kaito WATANABE ◽  
Ayumi TAKAHASHI ◽  
masaki IZAWA ◽  
Kazuhito MISAJI
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Lower Limbs

scholarly journals A comparative Analysis of PV Cell Mathematical Model

2021 ◽  
Vol 1795 (1) ◽  
pp. 012042
Author(s):  
M. Rasheed ◽  
O. Y. Mohammed ◽  
S. Shihab ◽  
Aqeel Al-Adili
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Pv Cell

scholarly journals Turbogenerator: Part 1: Simulation

2018 ◽  
Vol 7 (3.15) ◽  
pp. 277
Author(s):  
Lev Yu. Lezhnev ◽  
Alexey P. Tatarnikov ◽  
Arсady A. Skvortsov ◽  
Igor A. Papkin ◽  
Aleksandr S. Nekrasov
Keyword(s):  
Mathematical Model ◽  
Power Generation ◽  
Comparative Analysis ◽  
Power Plants ◽  
Computational Analysis ◽  
Exhaust System ◽  
Electric Machine ◽  
Distributed Power Generation ◽  
Technical Solutions ◽  
Work Done

The article describes the process of developing a turbogenerator for power plants of small and distributed power generation. The analysis of the component base for the turbogenerator was carried out, and thereof a comparative analysis of possible technical solutions was conducted. The work considered the installation variants of a turbogenerator in the exhaust system, an electric machine of a turbogenerator, types of turbines of a generator. A mathematical model for computation of the output effective and geometric parameters of a turbogenerator was described. The results of computational analysis were presented, and the parameters of the turbogenerator being developed were selected. Based on the results of the work done the conclusions were made  

Dehydration of Methylbutenes to Isoprene. Part 3: Comparative Mathematical Analysis of Methylbutene Dehydrogenation in Axial and Radial Reactors

2018 ◽  
Vol 18 (6) ◽  
pp. 55-60
Author(s):  
B. Sh. Gilmurakhmanov ◽  
P. V. Urtyakov ◽  
M. V. Nazarov ◽  
O. S. Roshchina ◽  
A. A. Lamberov
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Mathematical Analysis ◽  
Contact Time ◽  
Heat Energy ◽  
Energetic Efficiency ◽  
Target Product ◽  
Radial Reactor ◽  
Fixed Catalyst ◽  
Best Parameters

A mathematical model of the process of dehydrogenation of methylbutenes to isoprene was used for comparative analysis of energetic efficiency of two versions of modernization: (1) a system of consecutively connected two axial reactors with a fixed catalyst beds, and (2) adiabatic radial reactor with fixed catalyst bed. The purpose was to determine the dependence of yield (Y) and selectivity (S) to the target product on the heat energyQsupplied with vapor. In the two-reactor system, the best parameters (Y= 53.1 % andS= 82.9 %) were achieved atQ= 9.0 MJ/kg and contact time t = 0.8 s. At the same time, in the radial reactor the best performance (Y= 42.0 % andS= 86.1 %) was observed atQ= 7.8 MJ/kg andt= 0.8 s. Hence, the radial reactor consumes less heat energy (by 13.0 %) than the radial reactor for methylbutene dehydrogenation.

Choosing the Optimum Method of Treating the Ballast Water Onboard Ships

2013 ◽  
Vol 837 ◽  
pp. 727-732
Author(s):  
Nicoleta Acomi ◽  
Ovidiu Cristian Acomi ◽  
Alina Lucia Bostina ◽  
Aurel Bostina
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Ballast Water ◽  
Unit Cost ◽  
Aquatic Organisms ◽  
Treatment Method ◽  
Quality Parameters ◽  
Ship Owner ◽  
Ballast Water Treatment ◽  
The Cost

The transport of aquatic organisms from one place to another by ships ballast water has created substantial environmental impact on discharging areas. In order to avoid that, the International Maritime Organization (IMO) recommends treating the ballast water by different methods. The paper presents four methods of managing ballast water, accepted by the Organization: treating by filtration and irradiation with ultraviolet light, treating by de-oxygenation, treating with biocide and treating by heating. The comparative analysis of the treating technologies allows the ship-owner to choose such equipment by analyzing the advantages and the disadvantages. Considering that not only the quality parameters are important but also the cost, the study is completed by a mathematical model for calculation of unit cost for treating ballast water onboard. The purpose of this study is to develop an instrument for selecting the optimum method of ballast water treatment suitable for each type of vessel or voyage, so the ship-owners would be able to choose a treatment method comparing the costs, based on the specific requirements.

scholarly journals AVERAGED MODEL OF A BOOST–TYPE PULSE DC CONVERTER

2019 ◽  
pp. 168-174
Author(s):  
Dmitriy Alekseevskiy ◽  
Olena Mikhailutsa ◽  
Andriy Pozhuyev
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Current Mode ◽  
Widespread Application ◽  
Semiconductor Switches ◽  
Proposed Model ◽  
Reference Circuit ◽  
Circuit Elements ◽  
Averaged Models ◽  
Averaged Model

Urgency of the research. In the present paper, the questions of synthesis and application of the mathematical model of a boost-type DC converter, which has found widespread application in modern electrical devices and complexes, are considered. Target setting. Modeling of electrical complexes, which include semiconductor converters together with electromechanical, thermodynamic and other relatively slow processes, is faces the problem of a significant increase in simulation time. One way to solve this problem is to use the mathematical description of the semiconductor converter in the values averaged over the period of operation of the semiconductor switch. Actual scientific researches and issues analysis. In publications on this topic over the past few years, averaged models of DC converters of all basic types have been proposed. Both continuous and intermittent current modes are considered. Uninvestigated parts of general matters defining. In the models described in the publications, the continuous and intermittent current modes are considered as separate models in which ideal semiconductor switches are used. In addition, the adequacy of the models used is not given enough attention. The research objective. The objective of this work is to synthesize an averaged mathematical model of a boost-type DC converter, which would take into account the effect of direct voltage drops on the circuit elements in continuous and intermittent current modes, as well as assess the adequacy of applying the averaged approach. The statement of basic materials. In the article a description of an averaged mathematical model of a boost-type DC converter, which takes into account direct drops on the circuit elements and provides simulation both in continuous and intermittent current mode, is given. To confirm the performance and assess the adequacy of the proposed model, a joint simulation was performed using the proposed and reference (circuit) model, and its comparative analysis is given. Conclusions. The results of the comparative analysis confirmed the adequacy of the proposed model and revealed the occurrence of an error in the intermittent current mode, and also determined its cause.

scholarly journals A Mathematical Model to Study the Mechanical Information Induced by Lifting-Thrusting Needle

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Yi Yu ◽  
Wei Yao ◽  
Guanghong Ding
Keyword(s):  
Mathematical Model ◽  
Mechanical Response ◽  
Numerical Solutions ◽  
Stimulus Frequency ◽  
Angular Frequency ◽  
Mechanical Effect ◽  
Lower Limbs ◽  
Mechanical Stimuli ◽  
Mechanical Information ◽  
The Right

Focusing on the mechanical effect of traditional Chinese acupuncture, this study builds a mathematical model that simulates the mechanical process of lifting-thrusting needle. Analytic and numerical solutions are obtained to explore the mechanical information (displacement, strain, stress, and energy) in the skin tissue. Our results show that (1) needle manipulation leads to tissue displacement and mechanical stress field, but the needle should be inserted into the right position (about π/ω cm around the acupoint, where ω is the angular frequency) and enough depth (about 2 cm in lower limbs) to achieve effective mechanical stimuli; (2) the tissue displacement decays with an increase of distance from the stimulus position, more rapidly at higher frequencies; (3) there is an inverse relationship between the area of the ‘effective influence region’ (where shear strain > 0.2) and the stimulus frequency, which means larger needle movement is needed at higher frequencies to achieve a better curative effect; (4) more energy is required to maintain high frequency manipulation. This study proposes a preliminary comprehension of the mechanical response around the needle during the acupuncture process.

Walking on five legs: investigating tail use during slow gait in kangaroos and wallabies

2015 ◽  
Vol 63 (3) ◽  
pp. 192 ◽  
Author(s):  
Rebekah S. Dawson ◽  
Natalie M. Warburton ◽  
Hazel L. Richards ◽  
Nick Milne
Keyword(s):  
Comparative Analysis ◽  
Swing Phase ◽  
Lower Limbs ◽  
Relative Movement ◽  
Joint Angles ◽  
Video Recordings ◽  
Constant Height ◽  
Wide Range ◽  
The Mean ◽  
Tail Use

Pentapedal locomotion is the use of the tail as a fifth leg during the slow gait of kangaroos. Although previous studies have informally noted that some smaller species of macropodines do not engage in pentapedal locomotion, a systematic comparative analysis of tail use during slow gait across a wide range of species in this group has not been done. Analysis of relative movement of the pelvis, tail, and joint angles of the lower limbs during slow gait, using 2D landmark techniques on video recordings, was carried out on 16 species of Macropodinae. We also compared the relative lengthening of the tibia using crural index (CI) to test whether hindlimb morphology was associated with pentapedal locomotion. Pentapedal locomotion was characterised by three features: the presence of the ‘tail repositioning phase’, the constant height of the pelvis and the stationary placement of the distal tail on the ground during the hindlimb swing phase. The mean CI of pentapedal species was significantly greater than that of non-pentapedal species (1.71 versus 1.36; P < 0.001). This lends support to the hypothesis that the use of pentapedal locomotion is associated with the relative lengthening of the hindlimb, which in turn is associated with body size and habitat preference within the Macropodinae.

Mathematical Model of Generalized Assessment of the Rating of Similar Objects Based on Statistical Data from the Standpoint of Epidemiological Safety (on the Example of the Incidence of COVID-19 in the Regions of the Volga Federal District)

2021 ◽  
Vol 18 (5) ◽  
pp. 58-71
Author(s):  
V. M. Karaulov ◽  
L. V. Karaulova ◽  
E. V. Karanina
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Incidence Rate ◽  
Russian Federation ◽  
Statistical Data ◽  
Federal District ◽  
Disease Spread ◽  
Risk Of Disease ◽  
The Russian Federation

Th e article describes the construction of a generalized assessment of the incidence of COVID-19 in the regions of the Russian Federation. Th e mathematical model includes normalization of relative morbidity indicators, which allows comparing the incidence rate in diff erent regions and the degree of change in morbidity. Based on the developed scale of epidemiological safety and the risk of disease spread, the assessment of the level of disease and the spread of COVID-19 in the subjects of the Volga Federal District is carried out.The relevance of the study is due to the fact that a comparative analysis of the incidence of COVID-19 by region is currently one of the main conditions for identifying factors in the spread/localization of the disease, assessing the eff ectiveness of eff orts and developing a system of measures to counter the spread of the disease.

Gauging inequality among pastoralists

Focaal ◽  
2005 ◽  
Vol 2005 (45) ◽  
pp. 46-55 ◽  
Author(s):  
Paul Spencer
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Social Inequality ◽  
East Africa ◽  
Binomial Series ◽  
The Social ◽  
Different Types ◽  
Social Profiles ◽  
Over Time ◽  
Relative Concept

Poverty is a relative concept that is most meaningful within the context of social inequality in a particular culture. Among pastoralists in east Africa, often with mixed economies and herds that tend to fluctuate erratically over time, the problem of assessing poverty and wealth can be resolved by examining profiles of polygyny to provide a comparable index of wealth. Several profiles are examined in relation to a mathematical model based on the binomial series, with an emphasis on its social rather than mathematical implications. These series are especially apt because they closely follow the distribution of wives in a substantial sample of African societies, and they reveal different types of balances between competition and conformity associated with age and with status. The purpose of this essay is to redefine the problem of poverty in terms of the social profiles of inequality, leading toward a comparative analysis between cultures.

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