Run-time

Our global subdivision approach is not sensitive to such a situation. Over sufficiently long run times of direct simulation both methods eventually yield roughly the same results, see Fig. 6. 

Another method of detection of overfitting/overtraining is cross-validation. Here, test sets are compiled at run-time, i.e., some predefined number, n, of the compounds is removed, the rest are used to build a model, and the objects that have been removed serve as a test set. Usually, the procedure is repeated several times. The number of iterations, m, is also predefined. The most popular values set for n and m are, respectively, 1 and N, where N is the number of the objects in the primary dataset. This is called one-leave-out cross-validation. 

One limitation of clique detection is that it needs to be run repeatedly with differei reference conformations and the run-time scales with the number of conformations pt molecule. The maximum likelihood method [Bamum et al. 1996] eliminates the need for reference conformation, effectively enabling every conformation of every molecule to a< as the reference. Despite this, the algorithm scales linearly with the number of conformatior per molecule, so enabling a larger number of conformations (up to a few hundred) to b handled. In addition, the method scores each of the possible pharmacophores based upo the extent to which it fits the set of input molecules and an estimate of its rarity. It is nc required that every molecule has to be able to match every feature for the pharmacophor to be considered. 

The integral of the Gaussian distribution function does not exist in closed form over an arbitrary interval, but it is a simple matter to calculate the value of p(z) for any value of z, hence numerical integration is appropriate. Like the test function, f x) = 100 — x, the accepted value (Young, 1962) of the definite integral (1-23) is approached rapidly by Simpson s rule. We have obtained four-place accuracy or better at millisecond run time. For many applications in applied probability and statistics, four significant figures are more than can be supported by the data. 

The simulation or run time includes time for the system to equilibrate at the simulation temperature plus the time for data collection, while the trajectory evolves. Simulation times depend on the time scale of the property you are investigating. 

If the heating time t or cooling time t are non-zero, or if the run time tj. is non-zero and constant temperature is selected, velocities are adjusted (rescaled) during the molecular dynamics run to change the temperature of the system. 

If the average distance between obstacles is L, the run time between obstacles is... 

Pump shaft and driver shaft alignment is very important for long useful equipment life, and to extend the running time between repairs. Besides, good alignment reduees the progressive degradation of the pump. 

The next graph (Figure 10-1) indicates the expected eontinuous running time of rotating equipment with inereasing misalignment. As you soon. see, the alignment improves and so does the service time. 

You ve just seen six different concepts to control the environment inside the seal chamber and mechanical seal. Some methods are economical. Others are costly. Some have secondary side effects to contend with. Now let s consider the 14 difficult sealing situations and apply the environmental controls to extend the running time of the seal and pump. 

It is interesting to note that some pump users literally know that their pumps will fail after a specific time period. They understand that the running time of the pump should be maximized to have an acceptable yield in the process. This type of strategy is expensive since it raises a doubt of the continuity of the pump performance. To compensate, some plants install back up or redundant pumps. 

In the moment of starting a new pump, that pump is headed for the day when it will need repair even if the design and operation is correet. One faetor that determines the repair is internal wear. Imagine an ideal application where the pump is operating at its BEP and the system is stable. Does this condition ever exit If you answer yes, you are one of fortunate few. However at some point, even if it does not break, the pump will go to the shop because of internal wear. This chapter presents different sources of internal wear and suggestions to extend the useful running time of the pump. 

Concentrations are in mol%. indicates results corrected on no change in CII/i moles basis. Date 4/9/80 Run time in minutes=94.00... 

It is most likely that in designing a new FCC unit the expander will drive the air blower and produee enough horsepower in the end-of-bladelife eondition to supply the horsepower required by the air blower at the expander s end-of-run effieieney. There would also be an allowanee for deviations from expeeted expander performanee and air blower performanee. Thus, the expander ean be expeeted to have available, at start of run, a eonsiderable amount of exeess horsepower. This exeess horsepower must be used in some eeonomie manner without jeopardizing the eontinued safe operation of the FCC unit over its normal on-stream run time. 

The reciprocating compressor has several strikes against it when it comes to reliability, if the main consideration of reliability is long run times as would normally be expected from the dynamic type machines. It has a lot of parts and the parts are subject to wear. Before one jumps to the conclusion and totally excludes this compressor from consideration because of these factors, the positive aspects of this machine should be... 

Several steps can be taken to maximize the run time for the reciprocating compressor. Since wear is a function of rubbing speed, the piston speed can be kept to a minimum. Chapter 3 made recommendations for piston speed. Reliability problems due to valves are reputed to account tor 40% of the maintenance cost of the compressor. Valves are the single largest cause for unplanned shutdowns. Basically, valve life can he increased by keeping the speed of the compressor as low as practical. At 360 rpm, the valves are operated six times a second. At 1,200 rpm, ihc valves operate 20 times a second or 1,728,000 times in a day. It is not difficult to understand why the valves are considered critical. To keep the reliability in mind, valve type, material selection and application considerations such as volume ratio, gas corrosiveness, and gas cleanliness need attention by the experts. One final note is that while lubrication is an asset to the rubbing parts, it is not necessarily good for valve reliability. 

The type of compressor selected sets the quality of design. The API-based compressor is generally regarded as a higher quality than a catalog blower. Most of the chapter to this point has attempted to emphasize the many factors involved in design. Quality of conformance is a measure of how well the compressor met the specification. One of these measures is the achievement of the desired run time. Another measure is the inspection for conformance of the parts to the drawings. 

It does not calculate source emission rates. While it handles jets, it does so simply and docs not calculate the details of the jet motions and thermodynamics. It should not be used for strongly buoyant plumes. The error diagnostics are limited to checking the consistency of input parameters. Run time error diagnostics are missing but are rarely needed due to its robustness. 

Thus, for instance, 10% aqueous suspensions of the adsorbents produced by the various manufacturers are different (Table 25). It is not a matter of indifference whether Silica gel 60 or Silica gel 60 W (water-resistant) layers are employed, for the two differ appreciably both in pH and in running time and, hence, in selectivity... 

The type of plate, chamber system, composition of mobile phase, running time and detection reagent used must naturally all be recorded The sample protocol illustrated in Figure 62 can be employed... 

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