Obstacle-set method

An alternative approach, called the obstacle-set method, idealizes each musculotendinous actuator as a frictionless elastic band that can slide finely over the bones and other actuators as the configuration of the joint changes (Gamer and Pandy, 2000). The musculotendinous path is defined by a series of stndght-line and curved-line segments joined together by via points, which may or may not be fixed relative to the bones. 

Gamer, B. A., and Pandy, M. G. (2000). The obstacle-set method for representing muscle paths in musculoskeletal models, Computer Methods in Biomechanics and Biomedical Engineering, 3 1-30. 

In an attempt to remove this obstacle, approximate methods exemplified by the time-dependent Hartree (TDH) method have been developed. Here, the wave function is represented as a Hartree product of one-dimensional functions, and, as a result, the equations of motion for the wave packet are a set of coupled one-dimensional equations. The effort required is thus significantly reduced, but at the cost that the correlation between the degrees of freedom is no longer treated correctly. For strongly correlated systems like the vibronic coupled ones, TDH completely fails. 

The spatial temperature distribution established under steady-state conditions is the result both of thermal conduction in the fluid and in the matrix material and of convective flow. Figure 2. 9.10, top row, shows temperature maps representing this combined effect in a random-site percolation cluster. The convection rolls distorted by the flow obstacles in the model object are represented by the velocity maps in Figure 2.9.10. All experimental data (left column) were recorded with the NMR methods described above, and compare well with the simulated data obtained with the aid of the FLUENT 5.5.1 [40] software package (right-hand column). Details both of the experimental set-up and the numerical simulations can be found in Ref. [8], The spatial resolution is limited by the same restrictions associated with spin... 

Another popular method to estimate overpressures is the Baker-Strehlow method. This method is based on a flame speed, which is selected based on three factors (1) the reactivity of the released material, (2) the flame expansion characteristics of the process unit (which relates to confinement and spatial configuration), and (3) the obstacle density within the process unit. A set of semi-empirical curves is used to determine the overpressure. A complete description of the procedure is provided by Baker et al.18 The TNO multi-energy and Baker-Strehlow methods are essentially equivalent, although the TNO method tends to predict a higher pressure in the near field and the Baker-Strehlow method tends to predict a higher pressure in the far field. Both methods require more information and detailed calculations than the TNT equivalency method. 

In section 4, we established that the orbital truncation error represents a serious obstacle to the accurate calculation of AEs. Next, in section 5, we found that this problem may be solved in two different ways we may either employ wave functions that contain the interelec-tronic distance explicitly (in particular the R12 model), or we may try to extrapolate to the basis-set limit using energies obtained with finite basis sets. In the present section, we shall apply both methods to a set of small molecules, to establish whether or not these techniques are useful also for systems of chemical interest. 

Differences in criteria and methods of assessment of the characteristics and properties of herbal products may represent a risk for consumers and an obstacle to their free circulation within the Community. Therefore, in 1997, an ad hoc working group was established at the EMEA, which was tasked with addressing the problems of demonstration of quality, safety and efficacy. Subsequently the group became a permanent Working Party of the CPMP and developed a set of guidelines on the requirements and assessment of herbal medicines. 

In Section 2.4 we review the concepts and modelling methods for dispersion from typical accident releases in urban areas over the three characteristic scales, but starting from the local obstacle scale, where the release occurs. Then the multi-obstacle and finally the overall dispersion is considered. Following the rationale set out in Section 2.4, different approaches are described, from the most simple and rapid modelling... 

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