The understanding of humanbehaviour in the real world is important aspect of attempts to develop effective tools that simulate humans in areas such as ergonomics, manufacturing, transportation, psychology and archite...
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ISBN:
(纸本)9789814417730
The understanding of humanbehaviour in the real world is important aspect of attempts to develop effective tools that simulate humans in areas such as ergonomics, manufacturing, transportation, psychology and architecture. In this research, video observation studies and analysis is applied to understand the individual humanbehaviour in crowded spaces. Individual humanbehaviour is modelled and simulated using 'agents' with differing characteristics and abilities in a virtual environment. The focus is on developing a simulation method that supports an 'inclusive' sustainable environment which allows full participation of the elderly and disabled people in society.
A bold, but effective analytical method was demonstrated to extract dominant factors of deforestation, in a complex, non-controlled, interrelated, and multi-dimensional data structure of actual environment. human popu...
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A bold, but effective analytical method was demonstrated to extract dominant factors of deforestation, in a complex, non-controlled, interrelated, and multi-dimensional data structure of actual environment. human population was obtained as the factor in test field, followed by modeling based on the analytical result. An explicit mathematical relation defined by Weibull model emerged as an integral of the differential model. The equation was evaluated by non-linear regression, and it was revealed that a third factor of relief energy affects the process of deforestation, but the obtained model was in good agreement with stratified grid cell data of gentle slopes.
The objective of this study is to characterise the two-phase flow hydrodynamic behaviour of a rectangular air-lift loop reactor. The local and global gas hold-up, the global liquid circulation velocity, and the bubble...
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The objective of this study is to characterise the two-phase flow hydrodynamic behaviour of a rectangular air-lift loop reactor. The local and global gas hold-up, the global liquid circulation velocity, and the bubbles diameter, were measured and correlated to the superficial gas velocity or the pressure drop created by the gas sparger. The influence of geometrical and operating parameters was also studied. Then, a mathematical model was developed to predict the average gas hold-up (respectively, in the riser and the downcomer), and the global liquid circulation velocity. It was validated with experimental data. (C) 1999 Elsevier Science Ltd. All rights reserved.
In this paper, we outline the implementation of Hibler’s visco-plastic (VP) sea ice model into OpenFOAM, an open-source finite-volume modelling toolkit. Hibler’s visco-plastic model is arguably the most widely used ...
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Due to increasing product requirements the numerical simulation has become a powerful tool for the effective and efficient design of individual process steps as well as entire process chains. In order to model hot for...
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Due to increasing product requirements the numerical simulation has become a powerful tool for the effective and efficient design of individual process steps as well as entire process chains. In order to model hot forging processes with finite element based numerical methods realistic models are required which consider the detailed mathematical description of the material behaviour during the forging process, the surface phenomena at die and workpiece as well as machine kinematics. Although this data exist for several steel grades, yet general mathematical models for steel groups based on alloying elements like carbon content are not available. In hot forging the surface properties are strongly affected by the growth of oxide scale, which influences material flow, friction as well as product quality of the finished components. The influence of different carbon contents on oxide scale growth and material behaviour is investigated by considering three different steel grades (C15, C45 and C60). For a general description of the material behaviour, an empirical approach is used to implement mathematical functions so as to express the relationship between flow stress and dominant influence variables like alloying elements, initial microstructure and reheating mode. The oxide scale consists of three different components namely wuestite, magnetite and haematite. In order to take the oxide scale into account, additional models are required to describe the growth kinematic and flow behaviour of the oxide scale components. The mathematical relationship between oxidation time, temperature, carbon content and oxide scale height is based on Arrhenius approach. The deformation behaviour of oxide scale is separately modelled for each component with parameterized flow curves. This paper gives first approaches on the numerical modelling of plastic deformation of oxide scale in a hot forging process. The main focus lies on the involvement of the different materials as well as the calc
Concerning surgical and therapy planning for interventions at human eyes, especially at cornea and lens, computer based simulations are needed to predict the postoperative behaviour of the eye (vision) before surgical...
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ISBN:
(纸本)088986408X
Concerning surgical and therapy planning for interventions at human eyes, especially at cornea and lens, computer based simulations are needed to predict the postoperative behaviour of the eye (vision) before surgical acts at the patients. In the Institute of computer science in the Research Center Karlsruhe a simulation system is developed for the refractive surgery methods. Biomechanical simulations are performed with the commercial tool ANSYS, where morphometric and material data of the human eye are very important. The deformation of the cornea after interventions is the input for further optical simulations to give answer concerning the quality of vision.
In this paper a suggested control system for a solenoid coil is proposed. This control model is based on the employment of the electrical part of the solenoid with a conventional proportional, integral, and derivative...
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In this paper a suggested control system for a solenoid coil is proposed. This control model is based on the employment of the electrical part of the solenoid with a conventional proportional, integral, and derivative (PID) controller unit to investigate the performance of the control system. A mathematical model of the system has been derived, and the entire control system simulated via the MATLAB software package. The simulation process included tuning the gain parameters of the controller unit to achieve best behaviour of the system. In the computer simulation, two mathematical models of the electrical part of the solenoid coil were implemented;the first one involved the typical transfer functions of the coil, while the second dealt with an approximate model. The obtained results showed that the control system using the approximate model of the electrical part of the solenoid coil provides a more stable system and can thus be applied with acceptable response.
mathematical models of human operator play a very important role in the human-in-the-Loop manual control system. For several decades, modeling human operator's dynamic has been an active research area. The traditi...
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ISBN:
(纸本)9780791857199
mathematical models of human operator play a very important role in the human-in-the-Loop manual control system. For several decades, modeling human operator's dynamic has been an active research area. The traditional classical human operator models are usually developed using the Quasi-linear transfer function method, the optimal control theory method, and so on. The human operator models established by the above methods have deficiencies such as complicated and over parameterized, even for basic control elements. In this paper, based on the characteristics of human brain and behaviour, two kinds of fractional order mathematical models for describing human operator behavior are proposed. Through validation and comparison by the actual data, the best_fit model with smallest root mean squared error (RMSE) is obtained, which has simple structure with only few parameters, and each parameter has definite physical meaning.
Research on pedestrian crossing behaviour in urban areas is extensive and has contributed to very useful insights into the role of road, traffic and pedestrian characteristics on the crossing decisions of pedestrians,...
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Research on pedestrian crossing behaviour in urban areas is extensive and has contributed to very useful insights into the role of road, traffic and pedestrian characteristics on the crossing decisions of pedestrians, their compliance with traffic rules and the related safety. However, human factors are rarely incorporated in pedestrian crossing behaviour research. The objective of this research is to analyse the development of pedestrian crossing choice models on the basis of road traffic and human factors. For that purpose, a questionnaire was distributed to 663 respondents among pedestrians in the Shah Alam district. The respondents were asked to fill in a questionnaire about their travel motivations, ability characteristics, risk perceptions and preferences with respect to walking and road crossing, as well as their opinion on drivers, etc. From the modelling analysis, the results showed that there is a significant relationship between human Factor and Crossing behaviour;there were two components of human Factor that influenced pedestrian crossing behaviour to emerge, namely a "risk-taker" and a "rule-follower". Based on 'path coefficient' of human Factor analysis, this study concludes that a 'risk-taker' component contributed more to Crossing behaviour. The findings of this research can be used to evaluate the implementation of new pedestrian crossings and a redesign of existing pedestrian crossing environments.
This paper proposes a complete dynamical model of MEMS-based AC voltage reference sources. Static and dynamic models are investigated in both ideal and non-ideal conditions. State space equations are proposed to extra...
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ISBN:
(纸本)9781467356343
This paper proposes a complete dynamical model of MEMS-based AC voltage reference sources. Static and dynamic models are investigated in both ideal and non-ideal conditions. State space equations are proposed to extract the non-ideal dynamic model considering instability factors such as, offset voltage across dielectric layer and built-in voltage. These state space equations provide the opportunity to control system behaviour, enabling accurately stabilized reference voltages.
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