Global weighted mean

The global weighted mean of Z can also be shown to be zero ... 

One comprehensive study of surface DMS concentrations was that of Andreae and Raemdonck (42). Hie concentration of DMS was determined in 628 surface seawater samples, collected at 0.05 and 3 m. From this data base they estimated that a global weighted-mean DMS concentration in surface waters is 3.2 nmol I/1, higher than the values obtained in earlier studies (21.441. They noted that the DMS concentrations varied significantly from one location to the next and suggested that this patchiness might be related to primary production and also species variations from locale to locale. The correlation between chlorophyll a and DMS concentration for 225 samples was r = 0.53, = 0.001. 

Fig. 4.3. (A) Composite multispecies benthic foraminiferal Mg/Ca records from three deep-sea sites DSDP Site 573, ODP Site 926, and ODP Site 689. (B) Species-adjusted Mg/Ca data. Error bars represent standard deviations of the means where more than one species was present in a sample. The smoothed curve through the data represents a 15% weighted average. (C) Mg temperature record obtained by applying a Mg calibration to the record in (B). Broken line indicates temperatures calculated from the record assuming an ice-free world. Blue areas indicate periods of substantial ice-sheet growth determined from the S 0 record in conjunction with the Mg temperature. (D) Cenozoic composite benthic foraminiferal S 0 record based on Atlantic cores and normalized to Cibicidoides spp. Vertical dashed line indicates probable existence of ice sheets as estimated by (2). 3w, seawater S 0. (E) Estimated variation in 8 0 composition of seawater, a measure of global ice volume, calculated by substituting Mg temperatures and benthic 8 0 data into the 8 0 paleotemperature equation (Lear et al., 2000).

Global SMILES attributes were defined as (%,0,l,2,3)-code of six symbols si, s2, s3, s4, s5, and s6. The first symbol (si) is % . This symbol indicates this SMILES attribute is global. The s2 is descriptor of a presence of fluorine 0 means F symbol is absent in the SMILES 1 means there is one F symbol 2 means there are two F symbols finally 3 means that there are three or more F symbols in the SMILES the s3, s4, s5 are the same descriptors for Cl , Br , and O , respectively the s6 is the descriptor for the ( symbol in the SMILES. The brackets are tools to reflect the branching of molecular skeleton (Weininger, 1988, 1990 Weininger et al., 1989). Thus, ( and ) are indicators of the same phenomenon These SMILES attributes (i.e., brackets) have common correlation weight. 

The oxidation of most hydrocarbons requires a small increase in the mole number (decrease in mean molecular weight). Thus, contrary to the hydrogen-air situation, dissociation is needed in the hydrocarbon flames. Consider, for example, the overall global reaction for methane combustion... 

Figure 1.11, prepared by the U.S. Energy Information Administration, describes the global carbon cycle. It provides data that was collected in 2001. Since that date, the yearly anthropogenic carbon emissions (measured in carbon equivalent terms) increased from 6.3 to about 9 billion metric tons (over 1 ton per capita in the world). In November 2007, the National Academy of Science reported actual emissions for 2006 as 8.4 billion tons. Carbon equivalent means that the emission of 3.7 tons of COz is counted as the emission of 1 ton of carbon, so the 8.4 billion tons per year of carbon that enters the atmosphere owing to fossil fuel combustion corresponds to 33 billion tons per year of C02 because of the molecular weight ratio of COz to carbon (44/12). 

Owing to its gradient-descent nature, back-propagation is very sensitive to initial conditions. The choice of initial weights will influence whether the net reaches a global (or only a local) minimum of the error and, if so, how quickly it converges. In practice, the weights are usually initialized to small zero-mean random values between -0.5 and 0.5 (or between -1 and 1 or some other suitable interval). 

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