Computer processing speed limits

Modeling has become a powerful tool in the past 10-20 years with improved algorithms to predict operational conditions in glass melting furnaces, forehearths, regenerators, and annealing lehrs, etc. Furthermore, improvements in computer processing speeds have enabled the modeler to work from conventional computers rather than the exotic workstations of the past. However one needs to understand what it can do and what it cannot do . Someone must understand these limits, such that the interpreter is not left with a choice of Believe it or nof . 

In general, the processor speeds and memory capacities of modem personal computers are sufficient to support most systems (e.g., milliseconds timing resolution and response monitoring requirements). However, running these systems on older computers having a slower processing speed and limited memory capacity could have a detrimental impact on the accuracy of the test, so caution is recommended. 

There have been a number of computer simulations of block copolymers by Binder and co-workers (Fried and Binder 1991a,ft), and this work was reviewed in Binder (1994). Although computer simulations are limited due to the restriction on short chain lengths that can be studied, finite size effects and equilibration problems at low temperatures, the advantages are that the models are perfectly well characterized and ideal (monodisperse, etc.) and microscopic details of the system can be computed (Binder 1994). In the simulations by Binder and co-workers, diblocks were modelled as self- and mutually-avoiding chains on a simple cubic lattice, with chain lengths N = 14 to 60 for/ = 1.A purely repulsive pairwise interaction between A and B segments on adjacent sites was assumed. A finite volume fraction of vacancies was included to speed the thermal equilibration process (Binder 1994). 

The most accurate method of calculating the dynamical behaviour of surfactants is to integrate the equations of motion of all of the atoms in the system. It is obvious that the molecular dynamics calculations described in this chapter give only a rough estimate of the real situation. Such MD techniques require computer processor speeds and memory capacities that currently limit their applicability to a few nanoseconds of molecular motion. This is inadequate for many chemical processes of surfactants which occur on the microsecond (or longer) time-scales. Effects which are dependent on molecular diffusion cannot be investigated due to the... 

Abstract. Molecular dynamics (MD) simulations of proteins provide descriptions of atomic motions, which allow to relate observable properties of proteins to microscopic processes. Unfortunately, such MD simulations require an enormous amount of computer time and, therefore, are limited to time scales of nanoseconds. We describe first a fast multiple time step structure adapted multipole method (FA-MUSAMM) to speed up the evaluation of the computationally most demanding Coulomb interactions in solvated protein models, secondly an application of this method aiming at a microscopic understanding of single molecule atomic force microscopy experiments, and, thirdly, a new method to predict slow conformational motions at microsecond time scales. 

Parallel processing of information is a technique that speeds computer operations without the need to push the limits of existing technology by attempting to build increasingly faster processors. A typical outline of transputer architecture compared with that of a standard computer is shown m Figure 43.3. 

The results processor computes the test results from the raw data furnished by the AP and coUates these results together with the demographic patient data into test reports. Test results falling outside normal limits are flagged on the report to speed up the diagnosis process. These data managers can also store thousands of patient reports in their current memory. Some of the more sophisticated systems also store the actual reaction curves used to determine the test results. 

The exact computation of P W) in this simple one-dipole model is already a very arduous task that, to my knowledge, has not yet been exactly solved. We can, however, consider a limiting case and try to elucidate the properties of the work (heat) distribution. Here we consider the limit of large ramping speed r, where the dipole executes just one transition from the down to the up orientation. A few of these paths are depicted in Fig. 13b. This is also called a first-order Markov process because it only includes transitions that occur in just one direction (from down to up). In this reduced and oversimplified description, a path is fully specified by the value of the field H at which the dipole reverses orientation. The work along one of these paths is given by... 

High transmission rates can be achieved, if necessary, over the relatively short distances required in a process plant. The PCM equivalent of the 4-20 mA analog transmission system shown in Fig. 6.1 can operate at up to 9,600 baud for distances up to 3000 m. The standard RS-232C transmission link is limited to about 15 m at rates up to 20,000 baud. Higher speed interfaces (such as versions of the IEEE-488 connection) used for computer control systems can handle up to 20,000 bytes/s (which for an 8-bit system is about 1.6 x 105 baud). However, in this case, the distance between devices is limited to about 2 m(4). The more recent RS-422A standard allows the transmission of data rates of 107 baud over distances not exceeding 16.4 m and 105 baud over distances not exceeding 1220 m(9S). 

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