Spreadsheet, large

Note that different spreadsheets and different versions of the same spreadsheet vary in the details of the calculation but that the basic idea for all is to cany out the calculation for the top cell and fill in the remaining cells in the same column with the mouse—a very convenient technique for simple calculations on large data sets. Consult the Help section of your spreadsheet for specific details. 

The ubiquitousness of the personal computer and the increasing power of the program packages available for it have shifted the emphasis away from large, mainframe-based systems like PLATO. Instead, graphics are included in utihty programs such as equation solvers, spreadsheet processors, and word processors. 

Table 7.1 shows the construction of a typical activity chart using one of many computer spreadsheet packages. The cross (-F) identifies an activity in the plant and stars ( ) in the vertical lines denote where access to other activities is needed or an interrelationship exists. A wide scattering of the stars away from the diagonal line of crosses indicates large distances between the activities and thus large communicating distances. 

As each project task is completed, record the actual time and actual cost. Calculate variances and carry the cumulative total forward. This technique can easily be put into a spreadsheet format on your personal computer. Some large projects may be able to create this format for a report that uses cost and schedule data that is routinely captured by the company s computerized accounting system. Figure 51.10 illustrates a typical project control chart. 

So after having created the math spreadsheets and having improved the efficiency curves, I actually had to do the impossible now. I had to build it. What worried me was not just the fact that I had to obviously parallel over 10 large capacitors to get an effective ESR close to the target, but the fact that I had to ensure that the impedance of the intervening PCB traces also virtually canceled out. 

For your spreadsheet construction, we suggest that you set up the cells to move with the puff center. Otherwise, you will need a large number of cells. 

For reasons discussed above, we needed a complementary, ancillary tool for comparison of the mass spectra of components from multiple urine samples. We desired that the procedure have several characteristics (1) requires little if any manual data entry by the operator (2) utilizes data automatically generated by ChemStation and organized into Microsoft Excel spreadsheets (3) displays both retention times and mass spectral data in the same window (4) minimizes subjective operator judgments and (5) is simple and rapid to use. What emerged after several iterative improvements are the FindPeak macros discussed below. These are largely due to the expertise of Y. Aubut, with valuable input from J. Eggert. 

When the user, whether working on stand-alone software or through a spreadsheet, supplies only the values of the problem functions at a proposed point, the NLP code computes the first partial derivatives by finite differences. Each function is evaluated at a base point and then at a perturbed point. The difference between the function values is then divided by the perturbation distance to obtain an approximation of the first derivative at the base point. If the perturbation is in the positive direction from the base point, we call the resulting approximation a forward difference approximation. For highly nonlinear functions, accuracy in the values of derivatives may be improved by using central differences here, the base point is perturbed both forward and backward, and the derivative approximation is formed from the difference of the function values at those points. The price for this increased accuracy is that central differences require twice as many function evaluations of forward differences. If the functions are inexpensive to evaluate, the additional effort may be modest, but for large problems with complex functions, the use of central differences may dramatically increase solution times. Most NLP codes possess options that enable the user to specify the use of central differences. Some codes attempt to assess derivative accuracy as the solution progresses and switch to central differences automatically if the switch seems warranted. 

A historical control database can take on many formats, from a simple spreadsheet (e.g., Microsoft Excel) to a fully searchable database that is interfaced or a part of the laboratory s computer data collection system. Most laboratories that conduct large numbers of studies according to GLP standards have a validated computer data collection system, and some of these systems automatically compile control data ftom studies so the user does not have to reenter the data into a separate historical control database. However, because of the inflexibility of the data acquisition systems, many laboratories still compile their historical control data by manually entering into a stand-alone database, such as customized spreadsheet format (e.g., Microsoft Excel). 

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