Global Parallelism

The next step is to evaluate parallelism from a very broad view four anatomical sites, each treated with two different products. Recall that, if the slopes are parallel, no interaction terms are present. To evaluate whether the regression slopes are parallel on a grand scheme requires only that any interaction term be removed. 

Looking at the model breakdown, the interaction term is b(,Zs, where Z5 = time X product. So, if the slopes are parallel, the interaction term must be equal to 0 that is, b = 0. 

V is the number of indicator variables in full model minus number of indicator variables in partial model = 6—5 = 1. n-k-1 = 48-6-1 = 41. 

Step 5 Perform the computation. Table 9.20 presents the partial model. SSR(ft,ii) = 48.5813 (Table 9.18), 

Step 6 Because = 115.9274 Fj-=4.08, reject//q at a = 0.05. The slopes are not parallel at a = 0.05. To determine which of the equations are not parallel, run the four anatomical sites as separate problems. 

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The force decomposition algorithm maps all possible interactions to processors and does not require inter-processor communication during the force calculation phase of MD simulation. However, to obtain the net force on each particle for the update phase would need global communication. In this section, we will present parallel algorithms based on force decomposition. 

Most of the styrene monomer manufactured globally goes into the manufacture of PS and its copolymers, thus the price of the two tend to parallel each other (Fig. 32). 

PS is a global product, of which North America, Western Europe, and Southeast Asia are the principal consumers (Fig. 33). Global PS production capacity generally parallels the demand for the material (Fig. 34). However, the trend siace early 1980s has been toward narrowiag the gap between capacity and demand ia an effort to maximize the profitabiUty of the busiaess. 

The pattern of commercial production of 1,3-butadiene parallels the overall development of the petrochemical industry. Since its discovery via pyrolysis of various organic materials, butadiene has been manufactured from acetylene as weU as ethanol, both via butanediols (1,3- and 1,4-) as intermediates (see Acetylene-DERIVED chemicals). On a global basis, the importance of these processes has decreased substantially because of the increasing production of butadiene from petroleum sources. China and India stiU convert ethanol to butadiene using the two-step process while Poland and the former USSR use a one-step process (229,230). In the past butadiene also was produced by the dehydrogenation of / -butane and oxydehydrogenation of / -butenes. However, butadiene is now primarily produced as a by-product in the steam cracking of hydrocarbon streams to produce ethylene. Except under market dislocation situations, butadiene is almost exclusively manufactured by this process in the United States, Western Europe, and Japan. 

The students strongly approve of using current press accounts of global change issues, both scientific and policy related, in parallel with basic reference material. Some advised that future classes should require subscription to a high quality newspaper or journal, in addition to purchase of basic texts, for example one of those that were used in class. 

Assume that we have a program we will run on np processors and that this program has a serial portion and a parallel portion. For example, the serial portion of the code might read in input and calculate certain global parameters. It does not make any difference if this work is done on one processor and the results distributed, or if each processor performs identical tasks independently this is essentially serial work. Then the time t it takes the program to run in serial on one processor is the sum of the time spent in the serial portion of the code and the time spent in the parallel portion (i.e., the portion of the code that can be parallelized) is t = tg + tp. Amdahl s law defines a parallel efficiency, Pe, of the code as the ratio of total wall clock time to run on one processor to the total wall clock time to run on np processors. We give a formulation of Amdahl s law due to Meijer [42] ... 

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